Manure and Nutrient Management on Tile- Drained Landsmanure.mb.ca/projects/pdfs/Final Report 2015-12... · Figure 3-25 Illustration of a. Free Drainage, b. Controlled Drainage and

Manure and Nutrient Management on Tile-Drained Lands

A Literature Review

Prepared for: Manitoba Livestock Manure Management Initiative Inc.

Prepared by: Stantec Consulting Ltd. and PBS Water Engineering Ltd.

111440364

November 18, 2016

Disclaimer

This report entitled Manure and Nutrient Management on Tile-Drained Lands was prepared by Stantec Consulting Ltd. (“Stantec”) and PBS Water Engineering Ltd. for the account of Manitoba Livestock Manure Management Initiative Inc. (the “Client”). This report has been produced solely to introduce and provide a summary of existing information on the subject matter. Although the data and information used in this report was gathered from various reliable sources, the report is based upon certain assumptions which may differ from case to case. The report was compiled with due care and diligence, notwithstanding the contained information may vary due to changes in any of the factors and the actual results may differ substantially from the presented information. Any data summaries, analyses and interpretation of data, findings and conclusions are those of the research team and not of the governments of Canada or Manitoba. Stantec Consulting Ltd. and PBS Water Engineering Ltd. and their employees do not assume any liability for any financial or other loss resulting from reliance upon this report. The information contained in the report does not constitute professional advice, nor does it preclude any further professional advice. Any prospective user of this report should carry out additional due diligence and gather further information specific to the purpose of the user, including professional advice from a qualified consultant/technical expert.

Acknowledgements

This project is supported by the Manitoba Livestock Manure Management Initiative (MLMMI). MLMMI is funded by the Canada and Manitoba governments through Growing Forward 2, a federal-provincial-territorial initiative.

MANURE AND NUTRIENT MANAGEMENT ON TILE-DRAINED LANDS

Table of Contents

EXECUTIVE SUMMARY ............................................................................................................... I

1.0 INTRODUCTION ...........................................................................................................1.1 1.1 OBJECTIVES ..................................................................................................................... 1.1 1.2 BACKGROUND ............................................................................................................... 1.2

1.2.1 Subsurface Drainage Improvements in Manitoba ................................. 1.2 1.2.2 Nutrient Management ................................................................................ 1.3 1.2.3 Pathogen Transport ..................................................................................... 1.3 1.2.4 Regulatory Environment in Manitoba ....................................................... 1.4

2.0 HYDROLOGY AND HYDROGEOLOGY ........................................................................2.1 2.1 PRECIPITATION AND INFILTRATION ............................................................................... 2.1 2.2 SOIL WATER AND SHALLOW WATER TABLE .................................................................. 2.3 2.3 CAPILLARY RISE .............................................................................................................. 2.5 2.4 EVAPOTRANSPIRATION AND WATER TABLE ................................................................ 2.7 2.5 AGRONOMIC AND LANDSCAPE CONSIDERATIONS ................................................. 2.9 2.6 PREFERENTIAL FLOW..................................................................................................... 2.11 2.7 GEOLOGIC SETTING ..................................................................................................... 2.12

2.7.1 Groundwater Flow Regime ...................................................................... 2.12 2.7.2 Influence of Hydrogeology on Tile Drainage ........................................ 2.17 2.7.3 Implications of Hydrogeology for Tile Drainage Investigation and

Design .......................................................................................................... 2.21 2.7.4 Implications of Tile Drainage on Aquifer Water Quality ....................... 2.22

3.0 SUBSURFACE DRAINAGE .............................................................................................3.1 3.1 TILE DRAINAGE SYSTEMS ................................................................................................ 3.1 3.2 A BRIEF HISTORY OF TILE DRAINAGE IN MANITOBA .................................................... 3.4 3.3 BENEFITS OF TILE DRAINAGE .......................................................................................... 3.6 3.4 FACTORS AFFECTING THE ADOPTION OF SUBSURFACE DRAINAGE ........................ 3.7

3.4.1 Soil Landscape Factors ............................................................................... 3.7 3.4.2 Agro-Climatic and Agronomic Factors .................................................. 3.10 3.4.3 Salinity .......................................................................................................... 3.13 3.4.4 Hydrological and Hydrogeological Factors .......................................... 3.18 3.4.5 Water Quality ............................................................................................. 3.18

3.5 SUBSURFACE DRAINAGE STRUCTURES AND METHODS ............................................ 3.19 3.5.1 Uncontrolled Subsurface Drainage Systems .......................................... 3.20 3.5.2 Controlled Drainage Systems .................................................................. 3.22

3.6 BENEFICIAL MANAGEMENT PRACTICES FOR SUBSURFACE DRAINAGE SYSTEMS AND OPERATION .......................................................................................... 3.24 3.6.1 Controlled Drainage ................................................................................. 3.25 3.6.2 Bioreactors and Enhanced Bioreactors ................................................. 3.33 3.6.3 Saturated Buffers (Vegetated Subsurface Drain Outlet) ..................... 3.38 3.6.4 Alternative Surface Inlets .......................................................................... 3.41


3.6.5 Tile Water Capture and Recycling .......................................................... 3.44 3.6.6 Constructed Wetlands, Reconstructed Wetlands ................................ 3.48 3.6.7 Other Beneficial Management Options................................................. 3.53

4.0 NUTRIENT MANAGEMENT ............................................................................................4.1 4.1 FACTORS AFFECTING NUTRIENT AVAILABILITY IN AND LOSS FROM SOIL ................. 4.1

4.1.1 Synthetic Fertilizers vs. Manure as Nutrient Sources ................................ 4.1 4.1.2 Manure Properties ....................................................................................... 4.3 4.1.3 Soil Properties ............................................................................................... 4.4 4.1.4 Weather Conditions .................................................................................... 4.5

4.2 BENEFICIAL MANAGEMENT PRACTICES FOR NUTRIENT MANAGEMENT .................. 4.6 4.2.1 Determining the Right Nutrient Source ..................................................... 4.6 4.2.2 Application Rate ......................................................................................... 4.8 4.2.3 Timing of Application ................................................................................ 4.10 4.2.4 Application Method and Placement ..................................................... 4.12 4.2.5 Preferential Flow ........................................................................................ 4.16 4.2.6 Research Gaps for Nutrient Management of Manure on Tiled

Lands ........................................................................................................... 4.18

5.0 PATHOGEN LOSS FROM AGRICULTURAL FIELDS RECEIVING MANURE ......................5.1 5.1 FACTORS AFFECTING PATHOGEN TRANSPORT .......................................................... 5.1 5.2 BENEFICIAL MANAGEMENT PRACTICES TO REDUCE PATHOGEN TRANSPORT ....... 5.2

5.2.1 Application Timing and Rate ..................................................................... 5.3 5.2.2 Application Method .................................................................................... 5.4 5.2.3 Controlled Tile Drainage ............................................................................. 5.4

6.0 SYNTHESIS OF FINDINGS .............................................................................................6.1 6.1 NUTRIENT AND PATHOGEN TRANSPORT ON TILE DRAINED LANDS ........................... 6.1 6.2 BENEFICIAL MANAGEMENT PRACTICES FOR TILED LANDS RECEIVING

MANURE APPLICATION .................................................................................................. 6.4 6.2.1 Controlled Drainage ................................................................................... 6.4 6.2.2 Bioreactors .................................................................................................... 6.5 6.2.3 Saturated Buffers ......................................................................................... 6.5 6.2.4 Alternative Surface Inlets ............................................................................ 6.6 6.2.5 Tile Water Recycling .................................................................................... 6.6 6.2.6 Constructed and Reconstructed Wetlands ............................................ 6.7 6.2.7 Nutrient Management ................................................................................ 6.7 6.2.8 Other Beneficial Management Practices ................................................ 6.8

6.3 KNOWLEDGE GAPS ....................................................................................................... 6.9 6.3.1 Beneficial Management Practices Knowledge Gaps ........................... 6.9 6.3.2 Tile and Ancillary Structure – Investigation and Design ......................... 6.9

6.4 RECOMMENDATIONS FOR FUTURE RESEARCH AND DEVELOPMENT NEEDS ......... 6.10 6.4.1 Beneficial Management Practices Research Recommendations .... 6.10 6.4.2 Extension, Education and Training Materials ......................................... 6.11


7.0 REFERENCES .................................................................................................................7.1

LIST OF TABLES Table 3-1 Typical Stop Log Operations – Upper Midwest USA (Miller et

al. 2012) vs. Suggested Manitoba Operations ............................................ 3.30 Table 4-1 Common Fertilizers and their Characteristics ................................................ 4.2 Table 4-2 Ammonium Nitrogen Contents of Various Manure Types ........................... 4.4 Table 4-3 Distribution of Excreted Phosphorus in Feces and Urine for

Different Livestock ............................................................................................. 4.4 Table 4-4 The Relative Effectiveness of Nitrogen Fertilizer by

Application Method and Timing ................................................................... 4.15 Table 4-5 Nitrogen Availability in Manure and Loss as Affected by

Livestock Type and Manure Application Method ...................................... 4.15 Table 5-1 Survival Times of Some Bacteria in Soil ........................................................... 5.2

LIST OF FIGURES Figure 2-1 Water Cycle as it Pertains to A Cropped, Tile-drained,

Agricultural Field (modified from Stantec 2013) ............................................ 2.1 Figure 2-2 Rainfall Intensity and Infiltration Rate Impact on Runoff ............................. 2.2 Figure 2-3 Ponded Water due to Surface Runoff, High Water Table and

Topography ........................................................................................................ 2.3 Figure 2-4 Depiction of Water Storage in Soil Structure – Saturation,

Field Capacity and Wilting Point ..................................................................... 2.4 Figure 2-5 Conceptual Model of Free Water Table between Tiles (Matrix

Flow) .................................................................................................................... 2.4 Figure 2-6 Water Table Variation, Daily Evapotranspiration (ET), and

Hourly Evapotranspiration (ET) on a Corn Crop in Fine Sandy Loam Soil (Cordeiro 2013) ................................................................................ 2.5

Figure 2-7 Evapotranspiration from Shallow Ground Water by Cotton as Affected by Soil Texture and Water Table Depth (Grismer and Gates 1988) ................................................................................................ 2.6

Figure 2-8 Shallow Water Table Fluctuation versus Precipitation, Irrigation and Evapotranspiration, Corn Crop, CMCDC 2012 (AAFC) ................................................................................................................. 2.7

Figure 2-9 Tile Drainage Flow versus Rainfall; 1995 – Manitoba Corn Growers Demonstration Project (Harland et al. 1997) ................................. 2.8

Figure 2-10 Deep Ripping in Southern Manitoba to Remove Compaction Layer (Shewfelt) ................................................................................................. 2.9

Figure 2-11 Influence of Topography on Drainage and Drainability (Canada Manitoba Soil Survey, Soils Report D60 1988) ............................. 2.10


Figure 2-12 Surface Tile Inlet (OMAFRA) ........................................................................... 2.11 Figure 2-13 Mechanisms for Infiltration of Surface Water through Matrix

and Macro pores, and Associated Dissolved Phosphorus (DP) and Particulate Phosphorus (PP); Tile Drains in Cracking Clay Soils (Radcliffe et al. 2015); (cited in VAAFM and VANR 2016) ................. 2.12

Figure 2-14 Schematic Depicting Groundwater Recharge/Discharge ....................... 2.14 Figure 2-15 Conceptual Understanding of Distribution of Groundwater

Recharge and Discharge Zones and Associated Chemical and Thermal Environment (Modified from Toth 1999) ................................ 2.15

Figure 2-16 Mathematical models (Freeze and Witherspoon, 1967); illustrating the effect of topography (1) and a buried higher permeable layer (2) upon groundwater flow pattern and location of recharge and discharge areas ................................................. 2.16

Figure 2-17 Typical Soil Profile and Water Table (Almassipi Series) – Michalyna et al. 1988 ...................................................................................... 2.18

Figure 2-18 Buried Sand Channel Aquifer; North Portage Area; EM31 Map Delineation (AAFC unpublished data) ............................................... 2.19

Figure 2-19 Typical Hydrogeologic Setting and Piezometric Levels relative to Soil Surface as a function of a higher permeable underlying Limestone Aquifer (Rutulis 1985; Springs of Southern Manitoba) ........................................................................................ 2.20

Figure 3-1 Tile Drainage Plough and Sock Tile Being Installed in Southern Manitoba ............................................................................................................ 3.1

Figure 3-2 Slotted HDPE Drain Tile Covered with Filter Cloth ......................................... 3.2 Figure 3-3 Gravity Tile Outlet to Road Ditch ..................................................................... 3.2 Figure 3-4 Pumped Tile Outlet to Road Ditch .................................................................. 3.3 Figure 3-5 Typical Ponding of Water and Surface Runoff during Rain

Event in Southern Manitoba............................................................................. 3.4 Figure 3-6 Manitoba Corn Growers Demonstration Site – 1994 – Site C

(Harland et al. 1997) .......................................................................................... 3.5 Figure 3-7 Percentage of Cropped Land with Tile Drainage – Iowa,

Illinois, Indiana, Ohio (Kalita et al. 2007) ......................................................... 3.6 Figure 3-8 Soil Variability in Field that Is Tile Drained and Irrigated in

Southern Manitoba ........................................................................................... 3.8 Figure 3-9 CanSIS Drainage Classes; Canada Manitoba Soil Survey ........................... 3.9 Figure 3-10 Typical 1:20,000 Soil Survey Map Polygons .................................................... 3.9 Figure 3-11 Saturated Hydraulic Conductivity of Manitoba Soils by

Texture (after CANSIS) ..................................................................................... 3.10 Figure 3-12 Water Table Variation - CMCDC Winkler (AAFC Unpublished

Data) ................................................................................................................. 3.11 Figure 3-13 DRAINMOD RESULTS; 100 Year Record; Crookston Minnesota

Climatic Data; Bearden Loam Soil (Sands, 2013); DC – Drainage Coefficient; Drain – Tile Drain Flow; RO – Surface Run Off; W-Yld – Water Yield RO + Drain; C-Yld – Relative Crop Yield (%) .................................................................................................. 3.12


Figure 3-14 Water Table Variation on Tiled Land – Kelburn Farms – Clay Soil – 2010 – 10 m Tile Spacing (Tile Elevation in Black Line) (AAFC unpublished data) .............................................................................. 3.13

Figure 3-15 Horizontal EM38 Readings (Shallow) – 1995 to 2011 – Classified for Salinity (AAFC unpublished ..................................................... 3.14

Figure 3-16 Vertical EM38 Readings (Deep) – 1995 to 2011 – Classified for Salinity (AAFC unpublished) ........................................................................... 3.15

Figure 3-17 EM38 Readings by Year (Horizontal) (reference Figure 3-15) .................... 3.16 Figure 3-18 Veris Mapping – Morden Research Station (Stantec) ................................ 3.17 Figure 3-19 Tile Drainage Layout ....................................................................................... 3.19 Figure 3-20 Tile Drainage Layout ....................................................................................... 3.20 Figure 3-21 Typical Systematic Tile Drainage System – Uniform Spacing,

Pumped Outlet, Uncontrolled Drainage (Shewfelt) ................................... 3.21 Figure 3-22 Variable Spacing and Controlled Drainage Tile System near

Homewood, MB (courtesy of Bud McKnight) .............................................. 3.22 Figure 3-23 Agri Drain Control Structure (www.agridrain.com) .................................... 3.24 Figure 3-24 Agri Drain WaterGate Valve (www.agridrain.com) ................................... 3.24 Figure 3-25 Illustration of a. Free Drainage, b. Controlled Drainage and

c. Subirrigation (Satchithanantham 2013) ................................................... 3.26 Figure 3-26 Corn Yields for Hespler Research Project (Cordeiro 2013)......................... 3.27 Figure 3-27 Controlled Drainage versus Free Drainage

(Satchithanantham 2013) .............................................................................. 3.29 Figure 3-28 Drainage Intensity versus Relative Yield, Subsurface

Drainage, and Surface Drainage; Controlled versus Uncontrolled Tile Drains – DRAINMOD Modelling (Iowa); Crumpton et al. (2012) .................................................................................... 3.29

Figure 3-29 UW GWQ064 Fact Sheet No. 3 (2013) Restricting Tile Discharge (Cooley et al. 2013) ...................................................................... 3.31

Figure 3-30 Bud McKnight Seeds – Controlled Drainage Project – 300 Acres – Homewood Manitoba ...................................................................... 3.32

Figure 3-31 Woodchip Bioreactor; Containment Geotextile; Agri-Drain Diversion Structure; Morden Research Station ............................................ 3.34

Figure 3-32 Illustration of Woodchip Bioreactor (Christianson and Helmers 2011) .................................................................................................................. 3.35

Figure 3-33 Comparison of Woodchip Bioreactor Nitrate Removal to other Best Management Practices. (Christianson and Helmers 2011) ................................................................................................... 3.36

Figure 3-34 Spreadsheet Design Program – Bioreactors – Iowa State University ........................................................................................................... 3.37

Figure 3-35 Saturated Buffer - Schematic of Diversion, Distribution and Saturated Flow to Stream (Jayne USDA-ARS) .............................................. 3.39

Figure 3-36 Bear Creek and Maass Farm Data (Miler et al. 2012) – Flow Diverted as % Total Tile Flow – Data from Dan Jaynes, USDA-ARS ..................................................................................................................... 3.40

Figure 3-37 Hickenbottom Surface Inlet to Tile Drain ...................................................... 3.41


Figure 3-38 Water Quality Inlet – (www.agridrain.com) ................................................. 3.42 Figure 3-39 Blind Rock Inlet ................................................................................................. 3.42 Figure 3-40 USDA-NRCS Fact Sheet Blind Inlet ................................................................. 3.43 Figure 3-41 Transforming Drainage Research Sites Upper Midwest States

– Including 10 Recycling Tile Water Sites ...................................................... 3.45 Figure 3-42 La Salle Redboine Conservation District – University of

Manitoba – Drainage Water Capture and Recycling Site ........................ 3.46 Figure 3-43 Nitrate Reduction – Reconstructed Wetland (Site 3);

Minnesota Board of Water and Soil Resources (Peterson 2009) .................................................................................................................. 3.49

Figure 3-44 Average Observed and Predicted Nitrate – N Export (kg/ha/yr) for the Monitored Watersheds with Different Size Wetlands (Crumpton et al. 2012) .................................................................. 3.50

Figure 3-45 Measured (2004-2011) and Modelled Performance of Wetlands in Iowa CREP (Crumpton 2012) .................................................... 3.51

Figure 4-1 Effect of N Rate and Time of Application on Nitrate N Losses (Randall and Mulla 2001) .............................................................................. 4.11

Figure 4-2 Liquid Manure Injection System in Manitoba .............................................. 4.14 Figure 4-3 Manure Injection System – Aerway SSD Precision Manure

Application System (Manitoba) .................................................................... 4.18


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Executive Summary

The installation of subsurface drainage systems, generally through the use of tile drains, on agricultural land offers agronomic and economic as well as environmental benefits for agricultural producers. However, the use of livestock manure as a nutrient source for crop production on tile-drained cropland has raised questions and concerns regarding the potential for loss of nutrients and pathogens from the applied manure to tile drains, and possibly surface waterways fed by the tiles. The Manitoba Livestock Manure Management Initiative (MLMMI) retained Stantec Consulting Ltd. (Stantec) and PBS Water Engineering Ltd (PBS) to conduct a literature review focused on beneficial management practices for the application of manure on tile-drained lands. This report presents the findings of the literature review.

The objective of this literature review is to provide a summary of relevant published, non-published and extension-based research and demonstration on nutrient and pathogen transport from manure-amended lands to tile drains and associated surface water focused on:

• factors to be considered when determining whether subsurface drainage is beneficial, and the applicability of these factors to Manitoba conditions;

• nutrient and pathogen transport on agricultural lands, including a comparison of such transport between tiled and non-tiled lands;

• describing the structures, methods and approaches that are currently being used in controlled drainage water systems (those systems that go beyond conventional tile drainage) and their suitability for use under Manitoba conditions;

• summarizing the subsurface drainage system beneficial management practices (BMPs) that reduce the risk of nutrient and pathogen transport to water via tile drainage; and

• outlining knowledge gaps in the research that has been conducted to date and making recommendations regarding future research and development needs/priorities in the use of tile drainage in Manitoba.

The use of tile drainage in agricultural fields affects the hydrology and hydrogeology, that is the way water moves across the surface of the land and through the soil after it infiltrates. Simply stated, relative to the undrained condition, tile drainage shifts water movement from surface runoff to internal drainage via vertical and lateral drainage of free or gravitational water from the saturated zone if that zone is located at or above the depth of the tile. Conceptually, the implementation of tile drainage reduces the pathway of nutrient and pathogen loss from an agricultural field via surface runoff but introduces a new mechanism for entry of such into surface water via concentrated tile outflow while influencing the entry of constituents into groundwater systems. There has been less research conducted on pathogen entry into tile


compared with the body of knowledge regarding nutrients.

With tile drainage acres increasing in Manitoba (and other jurisdictions in Canada and the US), as producers attempt to improve productivity of their land and manage risk associated with excess water, concern over the environmental impacts of this management approach has grown, as has the focus on determining management practices to reduce these impacts.

The effectiveness of BMPs to reduce nutrient losses from fields is influenced by the likely primary nutrient transport pathways and the timing of nutrient movement from specific systems. This report describes controlled drainage, bioreactors, saturated buffers, alternative surface inlets, tile water recycling, constructed and reconstructed wetlands, nutrient management and infers these BMPs’ applicability to Manitoba conditions. Deciding on the appropriateness of BMPs for an operation depends on various factors including soil type (e.g., sand vs. loam vs. clay), crop, nutrient source (e.g., manure vs. synthetic fertilizer; solid manure vs. liquid manure), and land management practices like tillage, soil conservation, and drainage improvements. These factors are generally variable over time and geography – from regional to local (i.e., between field and within field) scales. Because the beneficial management practice needs to be customized to each operation or field, there is no “one size fits all” design. Understanding local environmental conditions and management systems is key to determining appropriate beneficial management practices.

A key consideration in nutrient and pathogen transport from applied manure is preferential flow (i.e., flow through fissures, cracks and macropores), which act to short circuit the flow of water through a soil. In the presence of tile drains, preference flow can result in relatively rapid movement of water from the soil surface to tile drainage lines. Soil type influences the nature of infiltration, as soils with high clay content are known to contain significant size cracks that can transmit higher levels of surface water to subsurface macropores. Additionally, conservation tillage practices preserve macro pores (e.g., root channels, worm holes, etc.) which can have the same effect as cracks. Water moving through preferential flow paths can carry higher levels of dissolved or particulate nutrients and pathogens than would be transmitted solely through the soil matrix. Conversely, where water flow to tile is mainly through the soil matrix, phosphorus and pathogens may be absorbed by the soil, while nitrate is still relatively mobile and prone to entry into the shallow groundwater and tiles if applied in excess of crop removal rates.

Beneficial Management Practices (BMPs) for tile drainage have been researched extensively in the Midwest USA and in Ontario. The target of these BMPs has been to reduce off-site movement of agrochemicals, improve efficiency of use of inputs for crop production, and understand production benefits of selected in-field BMPs. Limited research has been conducted in Manitoba, and while many BMPs established in other jurisdictions show promise for application in Manitoba additional research is required in many instances to confirm the applicability and efficacy of individual BMPs over the range of Manitoba variable agro-climatic and soil-landscape conditions.


iii

The following BMPs have strong potential to mitigate concerns associated with nutrient and pathogen transport into tile drainage water in Manitoba:

• Nutrient management – improved nutrient management holds significant promise for mitigating concerns with nutrient and pathogen transport to tiles. The principles of 4R – Right Source, Right Rate, Right Time and Right Place all have application to manure management for tile lands. Nitrogen management has been shown to have potential to reduce tile nitrate loading by 15% or more. Management of nitrogen could include reduced rates, split applications, inhibitors, soil testing, real time manure monitoring/injection systems, and variable rate technologies including mapping. The manure form and source dictates the nutrient value, the presence of pathogens, the volume of liquid, and consequently the impact on soil moisture conditions (and leaching conditions). Manure treatments may reduce pathogens (e.g., composting) or liquid amounts; both of which can lead to reduced potential for off-site contamination. The manure application rate must account for unbalanced nutrients in manure relative to plant needs and be implemented on the most critical nutrient for environmental protection. Commercial fertilizer may be required to supplement plant needs. Split applications are promising to reduce liquid volumes applied in order to prevent leaching. Equipment designed to distribute manure uniformly across the field, and new technology capable of variable manure nutrient application rates both show promise for improving nutrient uniformity. The potential for “tile avoidance” using GPS technology appears to be on the horizon, however this may create other agronomic challenges to producers (e.g., impracticality associated with equipment width relative to tile spacings, inconsistent nutrient application within the field). The timing of manure application must consider many factors such as soil temperature, weather conditions concurrent with application, soil conditions (e.g., soil moisture, soil cracking, shallow water table, tile flow), and anticipated weather conditions (e.g., frost, precipitation). Pre- or post-application tillage, uniformity of application (i.e. equipment design), smaller or split applications of liquid manure, are all methods of keeping the manure in the soil and out of the tile. Manure management on tiled lands must be tailored to the individual field, cropping rotation, equipment, soils, hydrogeology and tile drainage design. Fortunately, extension materials exist in other jurisdictions (e.g., Michigan, Ohio, Wisconsin) relating to manure management on tile drained lands that have applicability to Manitoba. A simple beneficial management practice will be to apply manure during a time period when the tiles are not anticipated to drain water. Fortunately, in Manitoba, water tables are often below the tile depth in fall, therefore fall manure application offers an opportunity to reduce entry of manure constituents into tile drainage water.

• Controlled Drainage - is the practice of creating water table management “zones” within the tile drainage design to allow for drainage and providing additional soil moisture for crop production relative to free drainage systems. While a significant component of the the environmental benefits attributed to controlled drainage in other geographies are limited in Manitoba due to frozen soil conditions for a portion of the year, limited Manitoba research confirms benefits in reduction of total nutrient loading and tile water outflows and Ontario researchers have shown a reduction of nitrate loading from the


application of liquid and solid manure to tiled lands relative to free draining tiles. Consideration to using controlled drainage during manure application, may be tempting due to the potential to “shut down” tile flows, however, this may result in surface ponding of water/manure on downslope portions of fields and may provide avenues for liquid manure to access lateral preferential flow paths. Furthermore, tiles need to be drained prior to freeze up and manure is typically applied after harvest, so there is little potential for fall nutrient and water uptake unless cover crops are also employed (this is addressed further below). Controlled drainage has been shown to significantly reduce pathogen transport in research fields in Ontario.

• Bioreactors - these engineered in-ground structures can provide water treatment to a portion of the tile flow. Bioreactors have the advantage of having little impact of tile flow rate and water levels in the drained field. Bioreactors are being promoted in the USA where they have been noted to reduce nitrate loading by nearly 40%, while research results have not yet been published on for a system installed in in Manitoba but appear promising. Amendments to bioreactors such as biochar appear to have promise in reducing phosphorus in tile outflow, but more research, design and testing is required. The benefit of bioreactors as a BMP is their small footprint, predictable costs, standardized design and operations, leading to their potential to be a relatively affordable and robust technology (e.g., land, design, construction). There are no local examples of bioreactors at the producer scale and no adoption of this promising technology in Manitoba to date. A major consideration for implementation will be enhancing cold water performance, which is currently being studied in Minnesota.

• Alternative surface inlets - alternative surface inlets filter the surface water trapped in topographic depression areas prior to entering the tile system. Blind inlets utilize graded sand and gravel filters to remove significant portions of suspended solids and associated particulate phosphorus and reportedly remove dissolved phosphorus as well. Reported removal rates exceed 65%. The studies reviewed did not comment on the use of surface inlets to treat incoming water for removal of nitrates or pathogens. To date in Manitoba, tile installers report very few installations of open inlets. There are no local examples of alternative surface inlets at the producer scale and no adoption of this technology in Manitoba to date.

The following BMPs related to buffer and constructed wetland development show promise for improving tile outflow water quality but more research is required to confirm benefits under Manitoba conditions and the implementation may be more challenging due to land requirements which may be “off-site” and involve entities other than the agricultural producer:

• Saturated buffers - a zone of saturated soil adjacent to the stream or waterway that the tile is discharging to as a means to treat a portion of the tile drainage water by diverting it to create are being promoted in the USA where they have been noted to reduce nitrate loading by nearly 50%. The research on saturated buffers is fairly scant but the focus on this research has been growing recently. The uniqueness of each buffer zone, namely the soils,


v

vegetation and hydrogeology will make design guidelines more difficult, and prediction of benefits less certain. Since the design involves limited structures and only additional tile materials, it is simple in construction and could be implemented by the tile industry. Unfortunately, unlike bioreactors which discharge to a single point, saturated buffer performance would be hard to monitor from an operational standpoint, as say part of a manure management plan. The literature reviewed does not report on the impact of saturated buffers on phosphorus or pathogens. There are no local examples of saturated buffers at the producer scale and no adoption of this technology in Manitoba to date. The USDA-NRCS has developed an interim standard for this practice, to guide implementation in the USA.

• Constructed and reconstructed wetlands - targeted constructed wetlands have been utilized extensively in Iowa to intercept and treat tile drainage effluent for the purposes of reduction of nitrate levels in receiving waters. Modelling studies in Iowa reveal that nitrate reductions of up to 55% are possible with a combination of targeted wetlands and nitrogen management. Wetland design is complex, as are their operations and maintenance. Concerns with constructed wetlands include land, design and construction costs; project siting and variable performance for removal of phosphorus. Wetland designs in Iowa utilize a ratio of wetland to drainage area of about 1%; and as such a modestly sized wetland can treat a significant number of acres at a sub-watershed scale. This study did not review the research on the impact of constructed wetlands on bacteria in the watershed. Monitoring of wetland performance is possible. There are no local examples of constructed wetlands for treatment of tile drainage water at the producer scale and no adoption of this technology in Manitoba to date.

• Two stage ditches and/or linear wetlands, as means to transport and teat tile effluent within modified linear drainage systems. Issues to consider would include cost of new ditching, ditch maintenance, ditch capacities (for flooding) land access and costs, and efficacy over time for nitrogen and phosphorus removal. Reduction of flood flows due to tile could be factored into the studies.

The following BMP has the potential benefit to water management, while the impact to tile water quality is uncertain:

• Tile water recycling - water recycling has recently become a consideration, especially where semi-arid conditions may exist, as a means to re-use drainage water for crops through irrigation or subirrigation. In Manitoba, tile water recycling has been practiced at two locations in the Morden-Carman area. More recently, research has begun to look at recycling surface and tile water in the Red River valley. The largest draw backs to recycling water will be the additional cost of storage (e.g., $2,500 per acre-foot); the need for water security for the irrigation component (e.g., tiles don’t run in a dry spring); and the impact of the tile water quality (e.g., salts, agrochemicals, pathogens, nutrients) on water, soil, plant and human health.


Future considerations could be given other beneficial management practices such as:

• Tile drainage design – could include more site/field/crop specific designs with respect to depth and spacing, area avoidance (e.g., overtop aquifers), in relation to potential for nutrient and water transport and as they may affect other design elements (e.g. CD, Bioreactors, etc.).

• Cover crops – as a means to utilize residual moisture and nutrients after harvest. Issues to consider would be increase to preferential flow, manure application equipment compatibility, suitable crops and crop rotations, net benefits to nutrient capture and release, impact on spring infiltration and runoff. While cover crops are uncommon in Manitoba and their application as a BMP may be limited, they may provide some value as a companion BMP under controlled drainage systems.

A summary of knowledge gaps for BMPs and tile drainage design in Manitoba is provided. Recommendations for research on BMPs under Manitoba’s agro-climatic and soil-landscape conditions and cropping production practices are provided, as are recommendations for public and producer education, extension and training.


Introduction November 18, 2016

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1.0 INTRODUCTION

The installation of subsurface drainage systems, generally through the use of tile drains, on agricultural land offers agronomic and economic as well as environmental benefits for producers. Land preparation and planting can be completed earlier in the season due to quicker and uniform drying of the soil surface as well as faster warming up of soils (Hill 1976; Harland et al. 1997; Mahoney et al. 2011; MAFRD n.d.1). Crops can establish a deeper root system and have greater soil water and nutrient use efficiency as well as reduced sensitivity to extreme wet and dry conditions (Mahoney et al. 2011). Crop yields and forage quality increase relative to undrained conditions (Mahoney et al. 2011). Tile drainage maintains and improves soil capability through a reduction of overland water flow resulting in reduced loss of soil through erosion and nutrients in runoff (Mahoney et al. 2011) and also through salinity reduction or control.

The use of livestock manure as a nutrient source for crop production on tile-drained cropland raises questions and concerns regarding the potential for loss of nutrients and pathogens from the applied manure to tile drains, and possibly surface waterways fed by the tiles (Bolton et al. 1970; Harland et al. 1997; Randall 2013; Harris 2015). The Manitoba Livestock Manure Management Initiative (M LMMI) retained Stantec Consulting Ltd. (Stantec) and PBS Water Engineering Ltd (PBS) to conduct a literature review focused on beneficial management practices for the application of manure on tile-drained lands. This report presents the findings of the literature review.

1.1 OBJECTIVES

The objective of this literature review is to provide a summary of relevant published, non-published and extension-based research and demonstration on nutrient and pathogen transport from manure-amended lands to tile drains and associated surface water focused on:

• detailing the factors that need to be considered when determining whether or not subsurface drainage is beneficial, and the applicability of these factors to Manitoba conditions;

• describing nutrient and pathogen transport from agricultural lands, including a comparison of such transport between tiled and non-tiled lands;

• describing the structures, methods and approaches that are currently being used in controlled drainage water systems (those systems that go beyond conventional tile drainage) and their suitability for use under Manitoba conditions;

• summarizing tile drainage system BMPs that decrease the risk of nutrient and pathogen transport to water; and



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• outlining gaps in the research that has been conducted to date and making recommendations as to future R&D needs/priorities in the use of tile drainage in Manitoba.

1.2 BACKGROUND

The installation of tiles on croplands receiving manure applications creates a complex system from agronomic, environmental and management standpoints.

Manure constituents include raw feces, urine, waste feed, spilled water, and bedding material (Sims and Sharpely 2005) which make it a wholesome source of nutrients for crops (OMAFRA 2009). Soil properties (e.g., moisture, temperature, texture, nutrient levels), and management practices (e.g., tillage practices, application rate and timing) affect the availability of nutrients in soil regardless of nutrient source. However, for soils receiving manure, the availability of nutrients is also affected by manure properties (e.g., livestock type, animal diet, bedding, manure treatment).

The quantity of nutrients in manure is not as important as the availability of these nutrients to crops. Synchrony of nutrient availability with crop uptake requires an understanding of manure properties and is important for sustainable use of manure as a nutrient source. Repeated applications of manure pose environmental concerns especially due to elevated levels of nitrate and phosphate in soil which can be leached or lost in surface runoff (Hao and Benke 2012).

The imbalance of nutrients, variability among manures (even for the same livestock type), difficulties in estimating nutrient availability, and the relatively low nutrient concentration that limits the distances over which manure can be profitably transported, present challenges for efficient use of manure as a fertilizer (Lory and Massey 2006). To offset these challenges, producers should implement practices that optimize the agronomic benefits of manure use while reducing the potential for environmental losses.

1.2.1 Subsurface Drainage Improvements in Manitoba

In Manitoba, the area under tile-drainage is estimated to be increasing at 15,000 – 20,000 acres a year and is made up of lands that range in soil texture from clay loam to loamy sands (Shewfelt pers. comm. 2016). Some tile-drained lands are known to be saline, and installation of tile drainage is an accepted management practice for mitigation of salinity issues in the crop root zone (Shewfelt pers. comm. 2016). Within the province, tile drainage is often associated with irrigated crop production, especially for potatoes. According to the 2006 Manitoba Irrigation Survey (Gaia Consulting Limited 2007), in 2006, potatoes made up more than 70% of the irrigated acres in Manitoba, with cereals and oilseeds making up about 17% of the irrigated acres. Based on potato-producer responses, approximately 4,300 acres of irrigated potato land were tile-drained in 2006, and 61% of irrigators indicated that tile-drain water was flowing in April/May/June of 2006 (Gaia Consulting Limited 2007). The seven tile drainage companies that are operating in Manitoba estimate having a current tile installation capacity of about 30,000




acre per year (Loewen pers. comm. 2016). However, the rising interest in tile drainage and area of tiled lands raise concerns about potential adverse effects on surface water quality due to nutrient and pathogen transport through tiles, particularly for lands that receive manure application.

1.2.2 Nutrient Management

Nutrient management refers to the adjustments in the source, rate, placement, and timing of nutrient applications to maximize crop nutrient removal while reducing the potential for nutrient losses (Manitoba Agriculture, Food and Rural Initiatives [MAFRI] 2008; Fertilizer Canada, n.d.).

Regardless of nutrient source (synthetic fertilizers or livestock manures), once a nitrogen-rich material is applied to soil, most of the nitrogen is converted by microorganisms in the soil to soluble forms of nitrate and ammonium that are readily taken up by plants (MAFRI 2008). Soluble forms of nitrogen can be lost from the root zone:

• as molecular nitrogen or nitrogen oxides through denitrification;

• as ammonia through volatilization;

• as a result of downward movement of nitrate beyond the root zone (leaching); and

• temporarily through immobilization, when soil microorganisms take up soluble nitrogen forms for their own growth (Havlin et al. 2005).

The application of phosphorus-rich materials (fertilizer or manure) to soil is entailed by chemical and biochemical processes, namely dissolution-precipitation, sorption-desorption, mineralization-immobilization, and oxidation-reduction (Sims and Sharpley 2005). The addition of phosphorus to soils in the form of synthetic fertilizer or manure causes an immediate increase in the concentration of soluble phosphorus, which in turn initially participates in easily reversible sorption process and is available for plant uptake (Sims and Sharpley 2005). Solid forms of phosphorus formed may later convert to less available forms reducing plant-available phosphorus. Applied phosphorus can be lost from the root zone:

• as sediment through erosion and in solution via runoff;

• as a result of downward movement beyond the root zone (leaching); and

• temporarily through immobilization, when soil microorganisms take up soluble phosphorus forms for their own growth (Sims and Sharpley (ed.) 2005).

1.2.3 Pathogen Transport

Unlike synthetic fertilizers, livestock manure is biologically active and contains microorganisms including bacteria, viruses and protozoa some of which cause sickness in people. While the




greatest risk of pathogen transfer from manured lands to surface waters is through runoff, transport of pathogens through tiles can result in surface water contamination (Spiehs and Goyal 2007). Some of the most commonly recognized pathogens from livestock (e.g., scherichia coli (E. coli), Salmonella, Campylobacter, and Yersinia) can result in illness for people who come into direct or indirect contact with the contaminated manure (Spiehs and Goyal 2007).

1.2.4 Regulatory Environment in Manitoba

1.2.4.1 The Livestock Manure and Mortalities Management Regulation

The Livestock Manure and Mortalities Management Regulation (133/2008) of The Environment Act (C.C.S.M. c. E125) prescribes requirements for the use, management and storage of livestock manure and mortalities in agricultural operations so that livestock manure and mortalities are handled in an environmentally sound manner. The regulation is administered under Manitoba Sustainable Development’s Livestock Program.

Per Section 12 of the regulation, livestock manure shall not be applied to land in a manner or application rate that may result in the concentration of residual nitrate nitrogen being:

• more than 157.1 kg/ha (140 pounds per acre) within the top 0.6 m (2 feet) of soil at any place in the application area for soils under agriculture capability classes 1, 2 and 3 (except Class 3 soils with a limitation of moisture deficiency, i.e., 3M or 3 MW);

• more than 101 kg/ha (90 pounds per acre) within the top 0.6 m (2 feet) of soil at any place in the application area for soil classes 3M, 3MW and 4; or

• more than 33.6 kg/ha (30 pounds per acre) within the top 0.6 m (2 feet) of soil at any place in the application area for soil class 5.

According to Section 13 of the regulation, before applying livestock manure to land as part of the fertilization program for a growing season, an operator shall submit a manure management plan for the growing season to the director for registration. The detailed instructions for completing phosphorus-related portions of the Manure Management Plan Form (Manitoba Conservation and Water Stewardship 2014) provide guidance for determination of maximum manure-phosphate application rate based on the following thresholds based on the Nutrient Management Regulation (see Section 1.2.4.2):

• If soil P is less than 60 ppm there are no restrictions to P2O5 application.

• If soil P is 60 ppm or more but less than 120 ppm, no more than two times (2x) crop removal P2O5 can be applied.

• If soil P is 120 ppm or more but less than 180 ppm, no more than the crop removal of (1x) P2O5 can be applied.




• If soil P is 180 ppm or higher, no manure can be applied. However, the director may approve application in an emergency situation or other extenuating circumstances.

1.2.4.2 The Nutrient Management Regulation

The Nutrient Management Regulation (106/2008) of The Water Protection Act seeks to protect water quality by encouraging responsible nutrient planning, regulating the application of materials containing nutrients and restricting the development of certain types of facilities in environmentally sensitive areas.

Section 3 of the regulation categorizes land into water-quality management zones for the management of nutrients, based on the land’s agriculture capability class:

• Zone N1, consisting of land belonging to, or having the characteristics of, soil class 1, 2 or 3 , other than 3M, 3ME, 3MI, 3MN, 3MP, 3MT, 3MW and any other subclass of soil class 3 having an "M" subclass designation;

• Zone N2, consisting of:

- land belonging to, or having the characteristics of, soil subclass 3M, 3ME, 3MI, 3MN, 3MP, 3MT, 3MW or any other subclass of soil class 3 having an "M" subclass designation;

- land belonging to, or having the characteristics of, soil class 4, and

- land belonging to, or having the characteristics of, soil subclass 5M, if it is being irrigated;

• Zone N3, consisting of land belonging to, or having the characteristics of, soil class 5 that is not included in zone N2;

• Zone N4, consisting of:

- land belonging to, or having the characteristics of, soil class 6 or 7, and

- land comprised of unimproved organic soils;

• Zone 5 consisting of non-agricultural land (e.g., land in a city, town, village, built-up areas).

Section 3 of the regulation defines nutrient buffer zones that should be maintained regardless of water-quality management zone to protect water bodies from nutrient contamination.

Section 7 of the regulation prohibits the application of a nitrogen-containing substance within nutrient management zones N1, N2 or N3 except:

• as a fertilizer; and either;




• in accordance with a registered plan; or

• in the absence of a registered plan, in a manner or at a rate of application that results in a residual concentration of nitrate nitrogen within the top 0.6 m (2 ft.) of soil at the end of the growing season, at any place within the application area, no greater than:

- 157.1 kg/ha (140 lbs/acre), in the case of land in zone N1;

- 101 kg/ha (90 lbs/acre), in the case of land in zone N2; or

- 33.6 kg/ha (30 lbs/acre), in the case of land in zone N3.

• Section 8 of the regulation prohibits the application of a phosphorus-containing substance to land in nutrient management zones N1, N2 or N3 except: as a fertilizer; and either

• in accordance with a registered plan; or

• in the absence of a registered plan:

- at a rate of application that does not exceed.

(A) two times the applicable phosphorus removal rate, if the soil test phosphorus levels are less than 120 ppm, or

(B) the applicable phosphorus removal rate, if the soil test phosphorus levels are 120 ppm or more but less than 180 ppm; or

- as otherwise permitted by subsection 12.1(3) of the Livestock Manure and Mortalities Management Regulation , Manitoba Regulation 42/98.

Section 12 prohibits the application of nitrogen and phosphorus sources to land in any nutrient management zone between (a) November 10 of one year, or any later date specified by the director; and (b) April 10 of the following year, or any earlier date specified by the director.

1.2.4.3 Tile Drainage Licensing

The installation of tile drains is considered a water control work under The Water Rights Act (C.C.S.M. c.W80) and requires a licence application to and approval from the Water Control Works and Drainage Licensing Section of Manitoba Sustainable Development. The application for a tile-drainage licence should include the following:

• Identify the location of the proposed tile drainage.

• Provide drawings of the tile drainage system (e.g., length, depth, slope, flow direction of nearby watercourses).




• Description of the proposed tile drainage system.

The Government of Manitoba has proposed a new regulatory approach to drainage and water retention that will categorize projects involving tile drains under Class 3 (Tile Drainage) in a conceptual Drainage, Retention, and Water Control Works Regulation under The Water Rights Act.


Hydrology and Hydrogeology November 18, 2016


2.0 HYDROLOGY AND HYDROGEOLOGY

The water or hydrologic cycle describes the existence and continuous movement of water on, in and above the soil-landscape. Figure 2-1 shows the major components of the water cycle for a cropped agricultural field. An understanding of these variables is critical to an understanding of the impact of tile drainage, its influence on the hydrologic cycle, and the movement of applied nutrients and pathogens.

Figure 2-1 Water Cycle as it Pertains to A Cropped, Tile-drained, Agricultural Field (modified from Stantec 2013)

2.1 PRECIPITATION AND INFILTRATION

A major hydrologic cycle component is precipitation of water in the form of rain and snow; or artificially via irrigation systems. The growing crop and/or the cultivated field can intercept the precipitation, and evaporation from the plant or soil surface can occur. Precipitation that

Infiltration

Capillary Rise Tile Discharge

Groundwater Out-flow

Soil Storage

Recharge

Saturated Zone

Vadose (unsaturated)

Zone

Precipitation

Irrigation

Evaporation Transpiration

Surface Run-on Surface Run-off

Groundwater In-flow Deep Recharge

Crop Uptake

Lateral In-flow Lateral Out-flow

Artesian Flow




reaches the ground surface can infiltrate into the soil and be stored in the crop rooting zone of the soil or transit through the rooting zone into the underlying subsurface soil or into the shallow water table, depending on the amount of precipitation and antecedent soil moisture conditions. Alternatively, if precipitation is of sufficient intensity to exceed the infiltration rate of the soil (i.e., water intake rate of the soil), surface runoff may occur. For a given area of land, run-off entering the area can exceed that leaving the area, resulting in ponding of water (see Figures 2-2 and 2-3). Soil surface factors and conditions including soil texture, frozen ground, antecedent soil water content, surface roughness, slope, and surface residue also influence how much water infiltrates a soil.

Figure 2-2 shows that soil texture and rainfall intensity interact directly. Surface runoff on a soil that has a relatively high infiltration capacity (e.g., loam, sand), or a soil subject to relatively low intensity rains, is typically minimal. In contrast, surface runoff on a soil that has a lower infiltration capacity (e.g., clay loam, clay), or a soil with a rainfall intensity that exceeds infiltration capacity, can result in substantive runoff. A saturated soil (see Figure 2-3) will have limited infiltration and generate surface runoff. Infiltration can be influenced by the presence of frozen ground – typically surface runoff rates will be higher when the soil surface is frozen. Spring snowmelt is subject to reduced infiltration and hence enhanced surface runoff conditions.

Figure 2-2 Rainfall Intensity and Infiltration Rate Impact on Runoff




Figure 2-3 Ponded Water due to Surface Runoff, High Water Table and Topography

2.2 SOIL WATER AND SHALLOW WATER TABLE

Within the soil, water is stored, being held loosely or tightly to the soil particles, depending on the soil water content, the size and shape of the soil particles, and associated soil tension. Within the vadose zone, the soil is typically not saturated; but once the field capacity of the soil is exceeded (see Figure 2-4) gravitational water freely moves downward, pulled by gravity towards a free water surface at some depth, which represents the water table.

Photo credit: Bruce Shewfelt




Figure 2-4 Depiction of Water Storage in Soil Structure – Saturation, Field Capacity

and Wilting Point

The top of the saturated zone is defined by the free water surface (see Figure 2-1); this free water surface is of prime significance to tile drains. If tiles are located above the surface of the free water surface, tile drainage systems will not move water. As the free water surface rises above the elevation of the tile, tiles drainage systems will accept water both vertically and laterally and move this water off the field until such time as the water level falls below the bottom of the tile drain. Conceptually, water will mound higher between the tiles with the maximum height of water table at one half the distance between the tiles (see Figure 2-5). The conceptual model assumes matrix flow, where water moves within and between the pore spaces of the soil, not including preferential or macropore flow which are described in Section 2-6.

Where: W – Tile Depth Below Ground; S – Tile Spacing; D - Depth below Tile to Restrictive Layer; H – Depth Below Ground Surface to Water Table at Mid Tile Spacing; h - Water Table Depth above Tile at Mid Tile Spacing. (http://climate.sdstate.edu/water/DrainSpacingCalculatorDocumentation.html)

Figure 2-5 Conceptual Model of Free Water Table between Tiles (Matrix Flow)

http://climate.sdstate.edu/water/DrainSpacingCalculatorDocumentation.html




2.3 CAPILLARY RISE

Of significance to the agricultural crop usage is the concept of capillary rise. As the plant removes water from its root zone, the resulting difference in soil water tension with the underlying soils compels water to move upwards from higher moisture to lower moisture areas. The significance of capillary rise is that it can allow movement of water from the shallow water table and into the crop rooting zone for uptake by the crop, and thus drive the water table lower than the elevation of the tile. The estimated height of capillary rise varies soil texture: very coarse sand - 0.8" (2.0 cm), coarse sand - 1.6" (4.1 cm), medium sand - 3.2" (8.1 cm), fine sand - 6.8" (17.3 cm), very fine sand - 16.0" (40.6 cm), silt - 40.0" (101.6 cm), and clay >40.0" (>101.6 cm)1.

Cordeiro (2013) provided quantitative proof of this phenomenon for Manitoba soils. Cordeiro (2013) showed that during a four-day period in August 2010, over which period no rainfall was received, shallow groundwater fell some 86 mm and contributed approximately 11 mm water to the crop, representing close to 83% of the crop water demand during that period (see Figure 2-6).

Figure 2-6 Water Table Variation, Daily Evapotranspiration (ET), and Hourly Evapotranspiration (ET) on a Corn Crop in Fine Sandy Loam Soil (Cordeiro 2013)

1 Manitoba Agriculture, Food and Rural initiatives (https://www.gov.mb.ca/agriculture/environment/soil-management/soil-management-guide/soil-salinity.html)




The fact that the water table can be drawn to depths approaching 2 m (see Figure 2-6) substantiates that under normal Manitoba conditions, as evapotranspiration begins to exceed precipitation, tile drains will no longer run. Furthermore, tile water will only resume running when the soil profile once again exceeds field capacity and downward, gravitational movement of water resumes and increases the level of the water table above the depth of the tile drains. At that point there is a delay between rainfall and tile drain flow, associated with recharging of the soil water content in the vadose or unsaturated zone to a point above field capacity after cessation of crop growth. Figure 2-7 provides a graphical representation of the influence of texture and depth to water table on the potential for shallow groundwater to meet a percentage of the crop evapotranspiration demand (Grismer and Gates, 1988) This figure illustrates that even at 2 m depth a shallow groundwater table in a sandy loam soil can provide a significant percent of crop water demand, driving the drop in the water table.

Figure 2-7 Evapotranspiration from Shallow Ground Water by Cotton as Affected by

Soil Texture and Water Table Depth (Grismer and Gates 1988)




2.4 EVAPOTRANSPIRATION AND WATER TABLE

The water table (see Figure 2-1) is not static; water can move laterally following the slope of the land, vertically under the influence of gravity and during capillary rise, and from upward underground pressure (artesian conditions) (see Figure 2-8). Typically, in Manitoba, for tile drains to run there must be a confining layer that contributes to restricting the downward movement or deep recharge rates. The presence of the confining layer in combination with a large variation in the balance of precipitation and crop evapotranspiration is expressed as a significant variation of water tables during an individual crop season (Cordeiro 2013).

Figure 2-8 shows the variation of the water table (line labelled A5) during 2012 at a Canada Manitoba Crop Diversification Center (CMCDC) corn field, south of Winkler, Manitoba (unpublished data, Agriculture and Agri-Food Canada [AAFC]). As implied in Figure 2-8, tiles did not run in 2012, being located within 100 cm of the ground surface on this plot; or 20 cm above the highest recorded water level. Figure 2-8 shows a gradual rise in water table during the spring when precipitation exceeded evapotranspiration. The water table began to fall towards the end of June, and was recharged slightly in early July by excess precipitation and irrigation, with a noticeable lag between rainfall and irrigation events and increased water table height. As the corn crop matured and required more water (e.g., in early July) evapotranspiration steadily drew on the water table, lowering it approximately 80 cm over a three-month period. After harvest in October, significant fall rains replenished soil moisture and then gravitational water percolated to raise the water table; to a stable pre-winter level.

Figure 2-8 Shallow Water Table Fluctuation versus Precipitation, Irrigation and

Evapotranspiration, Corn Crop, CMCDC 2012 (AAFC)




Figure 2-9 is illustrative of tile flow on imperfectly drained soils in Southern Manitoba. This site represents tile flow in spring, summer and fall, on a fine loamy sand (Almassippi soil series), where tiles are located at the sand/clay interface at about three feet depth (Harland et al. 1997). Of note, the tiles started flowing in early spring, presumably due to infiltration of snowmelt water and small rains or as the frost came out of the soil. During May the tiles responded directly and quickly to the rainfall events. The peak tile flow at this site corresponded to about 0.25 inch per day. As the corn crop started to utilize significant water the tiles stopped responding to the rainfall. This indicates that the water table was being drawn below the tiles by crop water usage through capillary rise. It was only after the crop had been harvested and late fall rains fell that the tiles ran again.

Figure 2-9 Tile Drainage Flow versus Rainfall; 1995 – Manitoba Corn Growers Demonstration Project (Harland et al. 1997)




2.5 AGRONOMIC AND LANDSCAPE CONSIDERATIONS

There are many individual soil and landscape factors that influence the water table, its interaction with tile drainage, and the movement of water and associated nutrients.

Figure 2-10 illustrates the use of deep tillage equipment to break up compacted layers that have been observed on fields in southern Manitoba. The producer’s objective for implementing this practice is to improve potential crop rooting depth and improve potential infiltration by breaking up an artificially restrictive layer resulting from farming operations and soil moisture conditions (Shewfelt pers. comm. 2016). In concept, this practice would result in more infiltration (see Figure 2-2A) and less runoff, which could result in a higher water table.

Figure 2-10 Deep Ripping in Southern Manitoba to Remove Compaction Layer (Shewfelt)

Other agronomic practices that may influence infiltration and hence water balance equations, include:





• use of dammer dykers to create indentations in potato rows to “trap” surface water and extending time for infiltration to occur;

• use of cover crops after harvest to protect soils from erosion and take up excess water and nutrients prior to freeze up;

• incorporation of solid and green manure to build soil organic matter; and

• minimum tillage methods and residue management.

Topography has a huge influence on water movement, accumulation and soil drainage (see Figure 2-11). In Figure 2-11, soils are largely differentiated on the basis of drainage. Soils located in higher elevation exhibit better drainage due to greater depth to the water table surface, while soils located in lower or depressional areas exhibit poorer drainage as a result of shallow depth to the water table surface largely from surface water run-on. In many jurisdictions, tile drainage is used selectively to drain lower lying areas of fields, including surface drainage connections to move ponded water through the tile drains. Surface inlets are used in Ontario to integrate surface drainage in depressional areas with subsurface drainage systems, as illustrated in Figure 2-12.

Figure 2-11 Influence of Topography on Drainage and Drainability (Canada Manitoba Soil Survey, Soils Report D60 1988)




Figure 2-12 Surface Tile Inlet (OMAFRA)

2.6 PREFERENTIAL FLOW

King et al. (2015) point to research showing that preferential flow paths (i.e., fissures, cracks and macropores) short circuit the flow of water within a soil. Soil type influences the nature of infiltration, as soils with high clay content are known to contain significant size cracks that can transmit higher levels of surface water to subsurface macropores (King et al. 2015; Klieman et al. 2015). Additionally, conservation tillage practices preserve macro pores (e.g., root channels, worm holes, etc.) which can have the same effect as cracks. Water moving through macro pores can make its way directly and rapidly to tiles and can carry higher levels of dissolved or particulate nutrients than would be transmitted through the soil matrix (VAAFM and VANR 2016) (see Figure 2-13). Frey et al. (2013) postulated that lateral seepage along preferential flow paths was associated with the plow layer. Figure 2-13 also highlights the trapping effect of matrix flow on dissolved and particulate phosphorus.

redit: OMAFRA




Figure 2-13 Mechanisms for Infiltration of Surface Water through Matrix and Macro pores, and Associated Dissolved Phosphorus (DP) and Particulate Phosphorus (PP); Tile Drains in Cracking Clay Soils (Radcliffe et al. 2015); (cited in VAAFM and VANR 2016)

2.7 GEOLOGIC SETTING

The geologic setting within which a tile drainage system operates influences the behaviour of the tile and vice versa. Understanding the influence that a tile drainage system could have on water quantity and/or water quality, requires an understanding of the groundwater flow regime, the geological setting and the position of the field and tile drains in relation to these features.

2.7.1 Groundwater Flow Regime

Manitoba has a wide diversity in geologic and hydrogeologic attributes, ranging from PreCambrian Bedrock to Karstic Limestone to Glaciated Terrian to Alluvial/Fluvial Deposits and much more (Betcher et al. 1995). While a detailed description of these attributes is beyond the scope of this report, a fundamental understanding of the impact that the variety of geologic/ hydrogeologic conditions can impose on a tile-drained field is important.




In its simplest form groundwater flow is governed by a simple equation (referred to as Darcy's Equation):

Q = KiA

Where:

• Q is volume of groundwater flow

• K is the permeability (more accurately the hydraulic conductivity) of the soil

• i is the gradient as groundwater flows from a higher elevation potential to a lower one under the influence of gravity

• A is the area through which groundwater flow is occuring

While groundwater exists virtually everywhere, there needs to be geologic conditions that create significant flow from higher areas to lower ones. Figure 2-14 illustrates a scenario where there is potential for groundwater to flow from left to right. The greater the elevation difference and the shorter the distance from left to right the greater the gradient would be. If the geology were all sand and gravel (e.g., the Assiniboine Delta Aquifer) the permeability would be very high and groundwater flow volumes would be considerable. However, if the geology consisted of a nearly impervious clay (e.g., Red River clays) then the volume of flow would be neglibible. Impacts of a field tile drainage anywhere along this profile would vary substantively depending on the geologic/hydrogeologic conditions.




Figure 2-14 Schematic Depicting Groundwater Recharge/Discharge

There has been considerable interest on the interaction between Groundwater Recharge/ Discharge Zone and field tile drainage (Oosterveen pers. comm. 2016). Groundwater Recharge/ Discharge Zones were defined by J. Toth (1963) (see Figure 2-15).

• Groundwater Recharge Zone is an area where groundwater flows downward from the land surface (i.e., piezometric water levels decrease with increasing depth).

• Groundwater Discharge Zone is an area where groundwater flows upward toward the land surface (i.e., piezometric levels increase with increasing depth) (see Figure 2-14).




Groundwater recharge/discharge zones occur at a range of scales, from local to regional. According to Toth (1963), the groundwater regime reflects the combined effects of topography and geology, which together affect the distribution, motion, chemistry and temperature of groundwater (see Figure 2-15). Often, groundwater discharge areas are represented on the landscape by a wetland area, saline soil zones and/or groundwater spring discharges (e.g., flowing water).

Figure 2-15 Conceptual Understanding of Distribution of Groundwater Recharge and Discharge Zones and Associated Chemical and Thermal Environment (Modified from Toth 1999)

Intuitively, one would expect tile drainage to be located primarily in groundwater discharge areas, but this is not always the case. There would be a need for field tile drainage in a recharge zone if a low permeability geologic layer preventing water from moving downward quickly enough for cropping purposes. In such an instance, tile drainage could reduce short-term water logging of soils but may have the impact of reducing overall recharge to the groundwater system. Tile drainage in a discharge zone seems more likely but this could result in excessive tile discharge, groundwater level suppression and potential reduction of wetland habitat.




In an effort to further understand the effect of geology on groundwater flow pattern, Freeze and Witherspoon (1966, 1967) used computer modeling of 2D-vertical geologic cross-sections to determine the effect of topography and geologic substrates of differing permeability upon groundwater flow pattern by simulating groundwater flow systems. They compared two 2D-vertical sections where the only difference between the two was the presence of a more pervious horizontal geological zone at depth in one section (see Figure 2-16). Determining the locations of discharge zones in a landscape is more complicated than just examining the topography of the surface because changes in the geologic conditions result in changes in the location, extent and magnitude of the groundwater recharge and discharge areas. Site-specific investigations are recommended.

Figure 2-16 Mathematical models (Freeze and Witherspoon, 1967); illustrating the effect of topography (1) and a buried higher permeable layer (2) upon groundwater flow pattern and location of recharge and discharge areas




2.7.2 Influence of Hydrogeology on Tile Drainage

With respect to the potential influence and interaction of tile drainage with groundwater it is important to understand where within the groundwater flow system a project occurs is and how the upward groundwater flow can be impacted by local geology/soil conditions. So while the variation in potential geology/hydrogeology in Manitoba is considerable, for the purpose of this report some simplifying concepts were adopted.

For tile drainage fields, geologic / hydrogeologic considerations can be broken into three general categories:

1. Zero or limited effects beyond the field margins.

2. Shallow geology/hydrogeology affects lateral water flow beyond the field margins.

3. Underlying geology/hydrogeology affects deeper groundwater flow conditions.

Category 1 – Zero or Limited Effects Beyond the Field Margins

Perched water table zones such as the area downslope of the Manitoba Escarpment, within the influence of the former Lake Agassiz, generally has negligible influence of flow from adjacent fields or from underlying aquifers. As such these fields fall into the first category, where hydrogeology has zero or limited effects. Tile drains installed within the zone of variation of the groundwater tables influence from evapotranspiration (e.g., 2 m) will typically only operate during time periods when cumulative precipitation exceeds evapotranspiration (see Figure 2-8).

For areas around Morden, Winkler and Carman, the geology is primarily a shallow layer (3 to 5 m) of nearshore silt and sand overlying lacustrine clay (see Figure 2-17). The clay is impervious enough to impede any short term upward or downward groundwater movement. As a result there is a perched water table that exists within the silt and sands and causes water logged soils during periods of wet weather (spring/fall) and low evapotranspiration. Water table level variation is primarily a function of the balance between evapotranspiration and rainfall; with a higher water table in the spring and late fall, and lower water tables in late summer (see Figures 2-17 and 2-8).

Elevation of tile drain placement is an important design criterion in order to allow the crop access to the shallow water table for growth, while preventing waterlogging of the plant root zone from excess rainfall and ensuring that the tile stays above the impervious clays. Controlled tile drainage is typically the optimum design solution for this type of scenario. When mainlines are installed deeper in such a situation (Figure 2-17), it is recommended that they be non-perforated, so as to not draw down the water table further than can be accessed by the plants.




Figure 2-17 Typical Soil Profile and Water Table (Almassipi Series) – Michalyna et al. 1988

Category 2 – Shallow Geology/Hydrogeology Affects Lateral Water Flow Beyond the Field Margins

Margin effects come into play with increasing geologic complexity, often associated with rapidly changing topography (e.g., the Manitoba Escarpment) and / or associated near shore geologic features. Alluvial fans, beach ridges, shale outcrops, and other geologic anomalies can lead to downslope hydraulic pressure resulting in springs, or groundwater discharge areas. These types of features are very local in nature and hence require intensive investigations if they are suspected to be in play (see Figure 2-18). If tile drains are installed within the water table zone of a shallow aquifer, the result can be tile drain discharge volumes in excess of the amount required to drain the field and with potential for tile water discharge year-round.

In the area directly north of Portage La Prairie, the geology was influenced heavily by the history of the Assiniboine River in relation to Lake Manitoba. Evidence of buried valley aquifers, remnants of the history of the Assiniboine River, can be shown by ground conductivity mapping




using an EM31 ground conductivity meter. Low EM31 readings indicative of the existence and location of an ancestral course of the Assiniboine River which has been subsequently filled up with sand and buried within the landscape near Macdonald, MB (Figure 2-18). These sand channels are linear, highly permeable, connected and are generally not artesian except where they may cross present day water courses or are intercepted by deeper man-made installations (e.g., irrigation ponds). A systematic tile drainage design in such an area could have groundwater flowing into tile drains within the silt/clay portions of the landscape and water flowing out of the tile drains into the sand contained within the ancestral channels. If there are water-quality issues in the tile drainage water then it will impact the water quality in the groundwater within the sand-filled channels.

Figure 2-18 Buried Sand Channel Aquifer; North Portage Area; EM31 Map Delineation (AAFC unpublished data)




Category 3 – Underlying Geology/Hydrogeology Affects Deeper Groundwater Flow Conditions

Underlying geology/hydrogeology effects have the most potential to interact with tile drainage IF artesian conditions exist and geologic conductivity is available. Examples of this type of feature are regional aquifers (e.g., Figure 2-19), and associated or defined regional discharge locations (e.g., Oak Hammock Marsh). The evaluation of these situations requires careful consideration and investigation of overburden thickness and the potential for activation or short circuit of the regional groundwater flow.

In the Interlake area of Manitoba, the surficial soils are underlain by karst limestones which are highly fractured, higher permeability and represent a regional aquifer. The surficial soils are overlying till and lacustrine deposits varying considerably in thickness. There are significant recharge zones where water readily seeps into the ground and significant discharge zones where flowing artesian conditions contribute to creek base flow, flow in ditches or discharge to wetland area (e.g., Oak Hammock Marsh) (see Figure 2-19). In these types of areas, if the overlying glacial till or clay is thin, or fissured, groundwater discharge areas may be coincident with poor field drainage, and tiles installed can intercept this upward flowing water.

Figure 2-19 Typical Hydrogeologic Setting and Piezometric Levels relative to Soil Surface as a function of a higher permeable underlying Limestone Aquifer (Rutulis 1985; Springs of Southern Manitoba)




2.7.3 Implications of Hydrogeology for Tile Drainage Investigation and Design

There are numerous permutations and combinations of groundwater recharge/discharge vs. local geological conditions that can affect the decision-making process for field tile drainage. Understanding the geological variability in a field and the potential for any margin defects is a critical element in the tile drainage decision/design. Tile drainage contractors have started to recognize the complexity of the influence of geology and have more recently made use of professional services intended to identify risks associated with geologic influences on tile performance (Oosterveen pers. comm. 2016).

The first step to review a field tile drain proposal is a Phase 1 report that summarizes the available soil/ geology/ groundwater information to determine if there are extraordinary considerations that need to be accounted for.

If it is determined that Category 1 (Zero or limited effects beyond the field margins) is the most probable scenario, then there will be negligible interaction between the field to be tile drained and the surrounding environment. In this case investigation could be limited to test holes to establish optimum tile drain elevations and soil samples (for permeability determination) to determine tile drain spacing with the design criteria of only having to account for water which falls as precipitation on the field. There are surface water flow conditions that can contribute to soil water logging but those are beyond the scope of the hydrogeologic analysis.

If Category 2 (Shallow geology/hydrogeology affects lateral water flow beyond the field margins) is the prevailing geology/hydrogeology condition, then there is concern for lateral flow of groundwater beyond the field margins. These conditions can be extreme enough to render tile drainage as unadvisable or benign enough to be a nuisance consideration. In the example provided in Section 2.7.2, a field tile drainage system which intersects a buried sand channel could;

• leach tile drainage water into the sand channel (considered an aquifer) potentially impacting water-quality downslope; or

• intercept groundwater flow in the buried sand channel resulting in excessive tile drain discharge, dilution of tile effluent water quality, lower of aquifer water levels.

Investigations would include georeferenced field electromagnetic surveys to accurately map the field margin defects, test holes to assess groundwater levels, groundwater quality and flow direction and assessment of potentially affected groundwater users in the vicinity; and mitigating tile design strategies (e.g., avoidance).

Finally, if Category 3 (Underlying geology/hydrogeology affects deeper groundwater flow conditions) is the case then an expanded geology/hydrogeology investigation is warranted. Tile drains which intercept regional groundwater flow in discharge area can affect water levels and quality over a significant area. There is potential to impact on wetland habitat, and incur year-




round tile discharge (a potential nuisance for municipal drains/culverts in winter). Groundwater is a valuable natural resource that needs to be carefully managed in order to meet environmental requirements and competing demands.

2.7.4 Implications of Tile Drainage on Aquifer Water Quality

Generally, the in-field impacts of tile drainage on aquifers are limited to the interception of upward moving or artesian flowing water. As such, the influence of tile drainage water quality on underlying aquifer water quality is minimal. However, there are conditions where field tile drains have the potential to impact the quality of groundwater. Given the potential for presence of dissolved or suspended constituents in tile water, two scenarios for potential impact of tile water quality on aquifers are considered.

The first consideration is the discharge course, drain or creek to which the tile water is flowing. In some instances, these discharge courses may cross or otherwise intersect and or be linked to aquifer recharge. The second consideration is closely related. In this scenario, perforated tile drains within a field cross an aquifer recharge area and tile water is actively draining into the recharge area. While both these scenarios can be rare occurrences, and tile water is mainly a concern for surface water quality (e.g., lakes and rivers), Figure 2-18 illustrates a geologic environment where both these scenarios are possible.


Subsurface Drainage November 18, 2016


3.0 SUBSURFACE DRAINAGE

3.1 TILE DRAINAGE SYSTEMS

According to the USDA-NRCS (2011) subsurface drainage is the installation of conduits “beneath the ground surface to collect and/or convey excess water. Excess water can be defined by saturation of the root zone that water which impacts plant growth negatively.”

Figure 3-1 shows a tile plough system which utilizes GPS controlled software to guide alignment, grade and depth of tile that is fed continuously through the plough. In Manitoba, a significant portion of tile installations (Shewfelt pers. comm. 2016) uses the filter cloth which is capable of preventing silt size particles from being carried into the tile (see Figure 3-2). This may also have significance when looking at cracking soils and “filtering” soil particles of any preferential water coming from the surface to the tile.

Figure 3-1 Tile Drainage Plough and Sock Tile Being Installed in Southern Manitoba





Figure 3-2 Slotted HDPE Drain Tile Covered with Filter Cloth

Tile outlets can be gravity or pumped depending on grade requirements, topography and opportunities to improve ditches (see Figures 3-3 and 3-4).

Figure 3-3 Gravity Tile Outlet to Road Ditch

Photo credit: Unknown





Figure 3-4 Pumped Tile Outlet to Road Ditch

In certain jurisdictions, subsurface drainage systems are connected to ponded surface water through the use of inlet structures. As such subsurface drainage can convey accumulated surface water to its outlet also. The practice of using surface water inlets is more common in clay soils and is utilized extensively in hummocky topography, in both cases to alleviate ponded water situations (see Figure 3-5). To date industry representatives (Loewen pers. comm. 2016) report using minimal surface inlets in Manitoba (see Figure 2-12).





Figure 3-5 Typical Ponding of Water and Surface Runoff during Rain Event in Southern Manitoba

3.2 A BRIEF HISTORY OF TILE DRAINAGE IN MANITOBA

The first known tile drainage system in Manitoba was installed on the Morden Research Station in the 1960s by the Canadian government (Shewfelt pers. comm. 2016). That system comprised of clay tiles, installed quite deeply, with very wide spacing. The system drained approximately 100 acres of land subject to high water table, and employed a series of pumped outlets. Interestingly, that system was augmented by the Morden Research Station in 2013, with the addition of pattern tiling at shallower depth.

Tile drainage was studied during the 1970s and 80s as part of the efforts of the Prairie Farm Rehabilitation Administration to look at large scale irrigation systems from the Assiniboine River south to the imperfectly drained soils near Carman and Winkler.

In the early 1990’s the Manitoba Corn Growers commissioned a small demonstration project at several sites from Morden to Haywood. A fact sheet was developed which indicated the typical drainage flow (see Figure 2-8; Harland et al. 1997) and recommended nutrient management as a BMP to reduce loss of nitrogen fertilizer in the form of nitrates into the tile. One of the sites was an 80 acre site near Roland, MB (see Figure 3-6).

During the 1990s, potato producers were early adopters of tile drainage, concentrating on imperfectly drained soils (e.g., Almassippi Sands).





Figure 3-6 Manitoba Corn Growers Demonstration Site – 1994 – Site C (Harland et al.

1997)

During the 2000s interest in tile has increased along with capacity to manufacture tile in Manitoba, resulting in a substantive capacity to install tile. At the time of this report (2016) there are seven tile drainage companies operating in Manitoba. The estimated capacity of the tile industry is close to 30,000 acres per year currently (Manitoba Agricultural Water Management Association [MAWMA] pers. comm. 2016). Influences on the utilization of this capacity are update, weather and land and commodity prices.

In southern Manitoba, farmers are considering many soils as candidates for subsurface drainage; and the tile drainage industry has recently begun to expand to meet a growing interest and demand from the farm community. Tile installations have extended beyond the potato industry and into other crops such as soybeans, corn, and other high value crops. A significant driver has been the disproportionate increase in land values, which has made investing in tile a reasonable option to an expanding land base. The current cost of tile is about $1000 (+-$200) per acre (MAWMA pers. comm. 2016).




Tile drainage is not a panacea for all agricultural lands and will not be adopted where natural subsurface drainage is adequate and/or surface runoff is already rapid. Even in areas where it has been long-recognized as a management option, tile still typically is done on less than 50% of the cropped land (Kalita et al. 2007; see Figure 3-7). In Canada, tile is a common agricultural practice in Southern Ontario, Quebec and parts of British Columbia; it is also gaining some traction in Saskatchewan and Alberta (Shewfelt pers. comm. 2016).

Early studies in Manitoba identified water quality of tile effluent as a potential concern (Harland et al. 1997). Even in US states with low percentages of tile drained cropland like Vermont, where an estimated 4% of total landbase is tiled (VAAFM and VANR 2016), water quality is a significant concern for tile drainage. Several other states (e.g., Wisconsin, Ohio) have produced fact sheets to guide managing tile drained landscapes for nutrient and manure applications (Hoorman et al. 2009; Cooley et al. 2013).

Figure 3-7 Percentage of Cropped Land with Tile Drainage – Iowa, Illinois, Indiana, Ohio (Kalita et al. 2007)

3.3 BENEFITS OF TILE DRAINAGE

According to the USDA-NRCS (2011) subsurface drainage can mitigate the following field crop conditions associated with shallow water table conditions:

1. Poor crop productivity stemming from plant health and vigor.




2. Poor soil conditions, leading to reduced capability to access the field (trafficability).

3. Reduction of salt in the crop root zone.

In Manitoba, tile drainage has grown from experimental to a considered option for producers looking to reduce the risk to crop loss and improve soil health and trafficability. This is largely reflected in the growth of the tile manufacturing and installation industry to its current level.

3.4 FACTORS AFFECTING THE ADOPTION OF SUBSURFACE DRAINAGE

Factors affecting the adoption of tile drainage as an agronomic practice include soil and landscape drainage restrictions, field access ability, balance of crop water use and crop water supply (evapotranspiration vs. rainfall), rising land prices, yield improvements or risk reduction. Risk factors associated with the adoption of tile drainage include risk to water quality and interaction with near surface aquifers.

3.4.1 Soil Landscape Factors

As previously discussed in Section 2.7.2, fields with seasonal high water tables within the effective crop rooting zone are ideal candidates for tile drainage (see Figure 2-1). Many of the applicable fields (see Figure 3-8) remain variable in texture, depth to impermeable layer, micro topography, and surface drainage patterns. The concept of one size fits all is slowly being replaced by the concept of precision drainage depending on the applicable soil factors. As nutrient management for tiled land becomes more commonplace, these factors will need to be accounted for in that planning.




Figure 3-8 Soil Variability in Field that Is Tile Drained and Irrigated in Southern Manitoba

The best-available source of soils data remains the Canada-Manitoba soil surveys. Soil resource information for a large portion of intensively farmed land in Manitoba exists at a scale of 1:20,000-50,000. The reports and associated data base of soils information provide the basis for rational decisions regarding the need for and potential benefits to implementation of tile drainage works.

The CanSIS soil data base is accessible online providing information on soil stratigraphy, soil chemistry, seasonal water table, soil hydraulic conductivity and other factors which may influence feasibility of tile drainage improvements. Tile drainage is typically targeted at the Imperfect (I) and Poor (P) drainage classes (see Figure 3-9). Individual soil properties can be determined for soils identified on a 1:20,000 map (see Figure 5-10) using an online look-up table at (http://sis.agr.gc.ca/cansis/soils/mb/soils.html). Generalized characteristics such as saturated hydraulic conductivity (e.g., Figure 3-11) can be used along with online tools to determine potential tile spacing. However, none of these tools can take the place of direct professional evaluation, additional field testing and local knowledge and experience.

Photo credit: Chris Unrau

http://sis.agr.gc.ca/cansis/soils/mb/soils.html




Figure 3-9 CanSIS Drainage Classes; Canada Manitoba Soil Survey

Figure 3-10 Typical 1:20,000 Soil Survey Map Polygons




Figure 3-11 Saturated Hydraulic Conductivity of Manitoba Soils by Texture (after CANSIS)

3.4.2 Agro-Climatic and Agronomic Factors

In Manitoba, there are seasonal imbalances between rainfall and crop evapotranspiration. In May and June precipitation exceeds evapotranspiration; and in July and August the opposite occurs (see Figure 3-12). Early spring snowmelt and associated rainfall events, saturate the soil root zone and subsequently leach water to the underlying water table. If that water table is impeded from downward or lateral drainage, the shallow water table will rise; saturating the soil root zone. As the water table gets closer to the root zone, the saturation risk for plant roots increases; especially when surface water accumulation and micro-topography impacts are taken into account.




Figure 3-12 Water Table Variation - CMCDC Winkler (AAFC Unpublished Data)

Monitoring reveals that the water table rise in May and June can approach 2 m or more (Cordeiro, 2013) (AAFC unpublished data; Figure 3-14), and that subsequent water table decrease can match that number. Equally important, the reduction in water table in late August also results in a delay in recharge of the water table in fall, even with large rainfalls, due to the need to replenish soil moisture depletion by the crop (e.g. to reach field capacity) (see Figure 3-14). The concept of water table variation due to influence of tile drainage and evapotranspiration is critical to understanding tile drainage design options as well as more advanced concepts of shallow tile drains, controlled drainage and subirrigation.

A significant study with respect to understanding the influence of climate on tile drainage was undertaken by the University of Minnesota (Sands 2013). The study utilized the program DRAINMOD (Skaggs et al., 2012) to simulate water table and crop response to tile drainage on several soil types typical in the Red River Valley. Weather inputs from 100 years of records were utilized to simulate the “with” and “without” drainage scenarios. Figure 3-13 illustrates the results




of one of the simulations, using data from Crookston, Minnesota for a Bearden loam soil.

Source: http://www1.extension.umn.edu/agriculture/water/reports/docs/final_report__developing_drainage_guidelines_for_rrb_sands.pdf

Figure 3-13 DRAINMOD RESULTS; 100 Year Record; Crookston Minnesota Climatic Data; Bearden Loam Soil (Sands, 2013); DC – Drainage Coefficient; Drain – Tile Drain Flow; RO – Surface Run Off; W-Yld – Water Yield RO + Drain; C-Yld – Relative Crop Yield (%)

Generally, the results of the DRAINMOD simulations were consistent across several differing soil types (Sands, 2013). Addition of tile drains within the Red River Valley was found to:

• Increase infiltration (e.g., 2.4 inches in Figure 3-13 for 0.5 inch DC).

• Decrease surface runoff (e.g., 2.3 inches in Figure 3-13 for 0.5 inch DC).

• Increase drain water (e.g., 2.9 inches in Figure 3-13 for 0. 5 inch DC).

• Increase in water yield (e.g., 0.6 inches in Figure 3-13 for 0.5 inch DC).

• Increase in relative crop yield (e.g., from 59 % to 96 % for UD and 0.5 inch DC respectively).

It is this basic change in the hydrology, and specifically in root zone saturation that allows for benefits to accrue to the crop and makes the investment in tile drainage considered a sound economic investment.

Significant water table monitoring on a variety of soils in Manitoba verifies that tile drainage can reduce water tables in spring. Appreciable increases in water table height occur in spring, triggering tile flow at repeated intervals, until such time as evapotranspiration draws the water table below the tile elevation (see Figure 3-14; tile at 90-cm depth).

http://www1.extension.umn.edu/agriculture/water/reports/docs/final_report__developing_drainage_guidelines_for_rrb_sands.pdf

http://www1.extension.umn.edu/agriculture/water/reports/docs/final_report__developing_drainage_guidelines_for_rrb_sands.pdf




Figure 3-14 Water Table Variation on Tiled Land – Kelburn Farms – Clay Soil – 2010 – 10 m Tile Spacing (Tile Elevation in Black Line) (AAFC unpublished data)

3.4.3 Salinity

Salinity is a result of the hydrologic cycle and the soil environment it interacts with. Salinity is a reality for many soil types in Southern Manitoba. Manitoba Agriculture’s web site provides a good summary of the causes of soil salinity, diagnostics, and management opportunities. (https://www.gov.mb.ca/agriculture/environment/soil-management/soil-management-guide/soil-salinity.html). Tile drainage is recognized as a potential means to help modify the salt balance within the root zone of certain soils.

Unpublished results from long term monitoring of a field south of Winkler illustrate the impact of tile drainage on slightly saline fine sandy loam soil. Both the shallow and deep electromagnetic (i.e., EM 38) mapping results of an 80 acre field that has been tile-drained and irrigated since 1995 reveal a significant shift in the extent and magnitude of the salinity levels in this field, resulting from improved sub surface drainage (see Figures 3-15 and 3-16). The maximum and minimum readings verify the change in state observed over time (see Figure 3-17).

-250

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AH1, AH2 & AH3 Precipitation Effects on Water LevelsNarrrow Spacing - 10m

Precipitation AH1 Water Level

https://www.gov.mb.ca/agriculture/environment/soil-management/soil-management-guide/soil-salinity.html

https://www.gov.mb.ca/agriculture/environment/soil-management/soil-management-guide/soil-salinity.html




Figure 3-15 Horizontal EM38 Readings (Shallow) – 1995 to 2011 – Classified for Salinity (AAFC unpublished




Figure 3-16 Vertical EM38 Readings (Deep) – 1995 to 2011 – Classified for Salinity (AAFC unpublished)




Figure 3-17 EM38 Readings by Year (Horizontal) (reference Figure 3-15)

Salinity is a major reason for tile drainage update in Eastern North Dakota (Scherer pers. comm. 2016). AGVISE, a private soils laboratory has documented soil and yield improvements associated with tile drainage (http://www.agvise.com/wp-content/uploads/2012/07/John-TileDrainageProject2002-2011.pdf); although they note the main changes are limited to the topsoil rather than the subsoil initially.

It is important to recognize the nature and distribution of the salts in order to pre determine the feasibility of reclamation with tile drainage. NDSU publication SF1617 provides a guideline for evaluation of the soils for suitability for tile drainage performance (NDSU, 2012). Of significance, this publication gives guidelines and a warning about sodic soils (i.e., soils with high concentrations of exchangeable sodium, typically with soil structural issues) and tile drainage, which may warrant special consideration by growers and installers prior to undertaking a tile project. Challenges with sodic soils may become more serious under tile drainage as leaching of soluble salts from the soil profile may result in relative increases in exchangeable sodium relative to other cations.

That there is a significant relationship between salinity, landscape position, surface and subsurface drainage should not be a surprise, indeed these relationships are an indicator of poor drainage and the potential benefit of tile drainage. Stantec (2013) found an increase in salinity in the low-lying, eastern portion of a poorly-drained field and attributed the salinity to long term surface ponding and subsurface water logging in this portion of the field (see Figure 3-18). Tile drainage was installed in this field, in 2013, and unpublished data has revealed large salt loading in the tile drain outlet flow (Sager pers. comm. 2015)

http://www.agvise.com/wp-content/uploads/2012/07/John-TileDrainageProject2002-2011.pdf

http://www.agvise.com/wp-content/uploads/2012/07/John-TileDrainageProject2002-2011.pdf




Figure 3-18 Veris Mapping – Morden Research Station (Stantec)




3.4.4 Hydrological and Hydrogeological Factors

The hydrological and hydrogeological factors impacting the adoption of tile drainage were described in Section 2.7. These factors (e.g., surface-water ponding, artesian flow) may lead to adoption of tile drainage without careful consideration of the downstream impacts.

Tile drainage companies have recently been requested by several regulatory bodies to document the anticipated downstream hydrologic impacts prior to approval of the outlet (MAWMA pers. comm. 2015, 2016). Professional services have been brought to bear on these issues by most if not all the tile companies operating in Manitoba, on a project by project basis.

3.4.5 Water Quality

Water quality is a significant risk associated with tile drainage. Cordeiro (2013) presented results showing elevated levels of nitrate, associated with leaching of nutrients applied for crop growth. Harland et al. (1997) observed elevated levels of nitrate from all sites installed as part of the Manitoba Corn Growers Demonstration project. Tile effluent from saline lands can be expected to have elevated conductivities as well (Harland et al. 1997). King et al. (2015) documented significant concerns regarding phosphorus transport to tiles, mainly associated with preferential flow paths. A large body of research is aimed at the reduction in nitrate outflow from tile drainage system (Hernandez-Ramirez 2011; Christenson and Helmers 2011, 2012; Crumpton et al. 2012; Christenson et al. 2013; Bock et al. 2015) and more recently to reducing phosphorus (King et al. 2015; Klieman et al. 2015).

Most of the literature related to manure and tile drainage is focused on the mobility of liquid manure. The potential for liquid manure to leach to tile drains and to affect tile water quality is clear (Hoorman et al. 2005; Hoorman et al. 2009; Frey et al. 2013; Harrigan et al. 2015). Yet, significant studies show reduced level of nutrients and no additional loading of bacteria for manure treated soils versus synthetic fertilizer (Randall 2003). Hoorman et al. (2005) postulated that the controlling factors for the movement of manure constituents to tile included: soil texture, initial water content, tillage history, amount of manure application, application method, water content of manures, and the amount of rainfall after application. To that list it would seem sensible in Manitoba to add the level or starting point of the shallow groundwater table that the tile drains are intercepting (see Figure 3-14). As described in Section 2, the balance between evapotranspiration and precipitation generally results in water tables at or above the tiles during April, May and June; whereas it can be substantially below the tile elevation by late August, September and October (see Figures 3-12 and 3-14). The depth to water table is a controlling factor in the potential for tile flow and indeed for surface runoff following a rainfall event. Similar results, showing low fall water tables accompanied by little to no tile flow, have been observed in North Dakota (Scherer pers. comm. 2016).




Currently in Manitoba, there are no options for tile water-quality improvement being substantively promoted for adoption by producers as part of tile drainage design and installation.

3.5 SUBSURFACE DRAINAGE STRUCTURES AND METHODS

Manitoba contractors utilize state of the art design and installation equipment and associated software. Traditionally, in many jurisdictions, tile drainage was installed in targeted areas (Figure 3-19), and this is certainly prevalent and warranted in hummocky topography (see Figure 2-10). In Manitoba, the prevalent nature of our fields, including flat topographies and uniform soils, has resulted in pattern drainage (e.g., parallel; see Figure 3-19).

Source: http://www.extension.umn.edu/agriculture/water/planning-a-subsurface-drainage-system/docs/planning-a-subsurface-drain.pdf

Figure 3-19 Tile Drainage Layout




The use of the latest design systems and software also means that contrary to planning recommendations, laterals are generally run perpendicular to the contours (see Figure 3-20). This results from the ability of the new software technology to automatically design and modify the pipe grade and depth to maintain minimum slope and minimum depth requirements. In this method the main is sized for a very flat slope and the laterals are run uphill using the computer/software as the design tool (see Figure 3-21).

Source: http://www.extension.umn.edu/agriculture/water/planning-a-subsurface-drainage-system/docs/planning-a-subsurface-drain.pdf

Figure 3-20 Tile Drainage Layout

3.5.1 Uncontrolled Subsurface Drainage Systems

In an uncontrolled sub-surface drainage system, the design starts at the outlet. The outlet and main discharge pipe are sized for the available slope and the required flow to match the desired drainage coefficient (i.e., lateral spacing and depth). In Manitoba, the tendency is to default to a 50-feet lateral spacing as a minimum consideration. This despite the data that suggests that wider tile spacing could be suitable for tiles in sandier soils (Sands 2013; University of Minnesota 2001), and tighter spacing may be required for heavier soils. As contractors are provided with more information on the relationship of tile spacing to texture, they have become more comfortable in providing more options to their clients. Figure 3-21 shows a uniformly spaced design at 50 feet, while Figure 3-22 shows a variable spacing design from 30–60 feet, based on soil texture, sub soil conditions, surface topography and salinity.




Soil texture has been the main determinant in the requirement for a tile sock. Manitoba has an appreciable proportion of soils with very fine sand/silt contents above 50%. These soils have the potential for the associated fine soil particles to move into the tile, and have resulted in the adoption of the tile sock to prevent this from happening. When clay content exceeds 25% it is generally considered that a tile sock may not be required, as the soil exhibits sufficient cohesive tendencies with prevent particulate movement.

Figure 3-21 Typical Systematic Tile Drainage System – Uniform Spacing, Pumped Outlet, Uncontrolled Drainage (Shewfelt)




Figure 3-22 Variable Spacing and Controlled Drainage Tile System near Homewood, MB (courtesy of Bud McKnight)

3.5.2 Controlled Drainage Systems

Controlled drainage systems have been promoted in the Upper Midwest USA for a number of years by an academic-research led task force that is supported by an industry led coalition (www.admc.com). Extension services from major universities (e.g., Ohio, Minnesota, Indiana, Iowa, Michigan) have researched and developed extension materials on the design of controlled drainage systems. In concept, the controlled drainage system is provided with a “structure” or number structures that can control the outflow of water from a zone of a field that is tile drained.

The control structures can be manual or automated and are being promoted as part of a new approach to tile drainage design, including by tile drainage companies based in the USA (http://www.ellingsoncompanies.com/our-services/agricultural-drainage/drainage-design-engineering/). The largest controlled drainage project in Manitoba is shown in Figure 3-22. This

http://www.admc.com/

http://www.ellingsoncompanies.com/our-services/agricultural-drainage/drainage-design-engineering/

http://www.ellingsoncompanies.com/our-services/agricultural-drainage/drainage-design-engineering/




project currently has 6 control structures (see Figure 3-23) on a 300-acre field with consideration to add two more in-ground controls (see Figure 3-24). The zones are separated by sub-mains shown in purple in Figure 3-22, which intercept and control water within a topographic limit of about 1 to 1½ feet.

Cordeiro (2013) and Satchithanantham et al. (2012) studied controlled drainage and subirrigation systems for corn and potatoes in Southern Manitoba. Both studies showed that reduction of tile outflow volume by controlled drainage had no negative impact the crop yield of the tiled plots. However, the systematic study of any net positive benefits of controlled drainage was masked by the simultaneous study of irrigation of the plots.

As shown in Figure 2-8, the potential for net benefit from controlled drainage in Manitoba is apparent in the period of time after planting and prior to large evapotranspiration periods, when there is an opportunity to store additional water above the tile depth using the control type structure. Given the ability of the crop to access this water during a drought scenario, it is felt that this could amount to an additional 1 inch of moisture for the crop during extended drought. Ayers et al. (2006) noted that shallow groundwater should reduce irrigation requirement and recommended joint management of tile and irrigation to effectively capture and use water to the best benefit of the grower. A more recent publication by University of California (Grismer 2015), suggests that shallow groundwater can be managed to help crop growth, depending on salinity levels in the water.

At this point, controlled drainage systems are not prevalent in Southern Manitoba, presumably as a function of some of the following observations (Shewfelt pers. comm. 2016).

• Lack of locally illustrated benefits.

• Lack of Manitoba based operational guidelines.

• Lack of Manitoba based research and monitoring (separated from irrigated effects).

• Additional information on net cost versus prescribed benefits is not readily available.

• Additional technical training to contractors not readily available.

• Lack of promotion of potential environmental benefits.




With respect to tile drained fields that are being considered for manure management, controlled drainage may provide an optional design that could result in the ability to control time of residence in the soil during manure injection operations. Again there is currently insufficient Manitoba data or experience with this approach. Some guidance on the potential benefits are provided by Frey et al. (2015), who studied the impacts of controlled drainage in Eastern Ontario, on fields where liquid swine manure was applied. Similarly, Drury et al. (2014) presented results for research on controlled drainage on clay loam soils in South West Ontario (see Section 3.6).

Figure 3-23 Agri Drain Control Structure (www.agridrain.com)

Figure 3-24 Agri Drain WaterGate Valve (www.agridrain.com)

3.6 BENEFICIAL MANAGEMENT PRACTICES FOR SUBSURFACE DRAINAGE SYSTEMS AND OPERATION

Given the positive impact of tile drainage on plant growth, surface run off reduction and overall nutrient utilization, tile drainage can be considered to be a beneficial management practice (BMP) from an agronomic or farm perspective (University of Guelph 2001). Despite these positive benefits, tiles are known source of excess nitrates and in certain instances, dissolved and particulate phosphorus as well (see Figure 2-13).

The Minnesota Agriculture Department has developed an Agricultural BMP Handbook (Miller et. al., 2012). This section draws heavily on the background research and options presented for tile drainage systems within that manual with Manitoba conditions/situations factored into the

http://www.agridrain.com/

http://www.agridrain.com/




review of the presented BMPs. The intent of the review is not to be prescriptive, but to highlight the many avenues available to farmers employing tile drainage to make a good practice better.

Implementation of tile drainage or water management BMPs is gaining momentum in the USA (http://www.cleanwateriowa.org/farm-practices.aspx). Iowa is a leading state in looking at nitrate movement into water ways and how to reduce it, with a goal of a 45 percent reduction in nitrogen and phosphorus losses to their waters. Since 2013, the Iowa Clean Water initiative has worked with 1800 farmers in 99 counties across Iowa, as well as 100 organizations collaborating in 32 demonstration projects. The projects are funded by farmers, organizations, the State and the Federal Government. Iowa has a large corn/soybean rotation and has a significant hog manure component to much of their production.

3.6.1 Controlled Drainage

Description

NRCS Standard (554) describes the practice of controlled drainage (CD), also known as drainage water management. Controlled drainage can be installed as part of a new project or can be implemented as a retrofit to an existing project. The elements of controlled drainage were described in Section 3.5.2.

Water-Quality Effects

In warmer climates (e.g., upper mid-west USA, Southern Ontario) benefits to water quality are largely attributed to the cessation of tile water flow during the period from November to March; which reduces the volume of tile flow significantly. Miller et al. (2012) do not attribute a significant reduction to change in the nitrate level in the drainage water. Results presented in ADMC (2011) for the 5 State Conservation Innovation Grant study indicates nitrogen load reductions of 20 to 60% depending on climate and agronomy. In Manitoba, Cordeiro, (2013) studied free drainage (and overhead irrigated) and controlled drainage (and subirrigation) on plots growing corn (2010 and 2011). Satchithanantham, (2013) simultaneously studied free drainage, controlled drainage and subirrigation of potatoes on adjacent plots (2010 and 2011). Figure 3-25 (Satchithanantham, 2013) illustrates the operational differences between free drainage, controlled drainage and subirrigation.

http://www.cleanwateriowa.org/farm-practices.aspx




Figure 3-25 Illustration of a. Free Drainage, b. Controlled Drainage and c. Subirrigation (Satchithanantham 2013)

Cordeiro (2013) concluded that Controlled Drainage Subirrigation (CDSI) reduced drainage outflow by 39% in 2011 in comparison to Free Drainage Overhead Irrigation (FDIR). Additionally, Cordeiro (2013) concluded that CDSI reduced nitrogen loading versus FDIR from 36 to 10 kg/ha NO3-N; and phosphorus loading from 0.27 to 0.08 kg/ha PO4-P. Yield differences reported in Cordiero (2013) for the four conditions tested are shown in Figure 3-26. The data is conclusive only to the value of the irrigation. The amount of water reportedly “saved” in 2011 between the CDSI and the FDIR was the difference between an average of 87 mm for FDIR and 53 mm for CDSI; or 34 mm (1 ½ inch); consistent with expectation for Manitoba.




Notes: NDNI – No Drains, No Irrigation; NDIR – No Drains, Overhead Irrigation; FDIR – Free Flowing Sub Surface Drains, Overhead Irrigation; CDSI – Controlled Sub Surface Drains; Sub Irrigation.

Figure 3-26 Corn Yields for Hespler Research Project (Cordeiro 2013)

Satchithanantham (2013) concluded that during the controlled drainage period (June to October) controlled drainage could reduce tile flow significantly. However, when taking into account the closer tile spacing for the subirrigation trials, the subirrigated plots actually increased tile outflow during the free draining period (April – May) (see Figure 3-27). In all cases, tiles were allowed to be free draining from November to March, in order to prevent tiles from freezing solid. Satchithanantham (2013) also noted overall reductions in nitrate loading but not in phosphorus loading during 2011.




Expectations for controlled drainage impact on nutrients varies between researchers and extension publications. Miller et al. (2012) concluded that research shows little impact of controlled drainage on nitrate concentrations. Drury et al. (2014) on the other hand, observed reduction in nitrogen concentrations by 15 to 33%, and nitrate loads by 38% when compared to uncontrolled or free tile drainage. Drury et al. (2014) further noted that controlled drainage in combination with cover crops reduced tile drainage nitrate concentrations and loading by 47%.

Regarding phosphorus, Satchithanantham (2013) indicates concentrations may increase due to water being retained in the root zone, where higher phosphorus levels existed. The potential for higher phosphorus concentrations in tile water due to controlled drainage was confirmed by Frey et al. (2013). They measured significant increase in phosphorus concentrations in tile water from controlled drainage (CD) tiles versus uncontrolled drainage (FD) tiles, during the first significant rain event after application of liquid manure. They postulated that the CD water levels induced lateral seepage along the plowpan layer, thus connecting preferentially with the tile drains, and increasing the tile P concentration levels. This was supported by higher turbidity levels in the CD water (Frey et al. 2013). It is thought that the liquid manure in the free drainage plots may have initially seeped vertically below the layer where preferential lateral flow was possible (Frey et al. 2013). In the end, the CD and FD nutrient loading was similar, but CD reduced bacterial counts in tile water significantly (Frey et al. 2013).

Crumpton et al. (2012) suggested that more intense drainage coupled with wetland treatment systems (see Section 3.6.6) was a better nutrient management strategy then controlled drainage within the Des Moines Lobe in Iowa. Primary reasons cited were the reduction in tile outlet flow associated with implementation of controlled drainage was largely matched by an increase in surface water flow (see Figure 3-28). While controlled drainage may decrease total flow and nitrate transport, the increase in surface runoff was associated with increasing phosphorus loading. In addition, within the Des Moines Lobe in North Central Iowa the rolling topography was not well suited to controlled drainage. Instead, Crumpton et al. (2012) argued that increasing tile drainage intensity and then treating the resulting nitrate loading would lead to a lower overall nutrient export, considering both phosphorus and nitrogen.




Figure 3-27 Controlled Drainage versus Free Drainage (Satchithanantham 2013)

Figure 3-28 Drainage Intensity versus Relative Yield, Subsurface Drainage, and Surface

Drainage; Controlled versus Uncontrolled Tile Drains – DRAINMOD Modelling (Iowa); Crumpton et al. (2012)




Design and Cost Considerations

The amount of water that can be stored through controlled drainage amounts to the difference in water levels during the time periods that it is employed. Table 3-1 shows typical control structure operations in wetter (non-freezing) climates (Miler et al. 2012). In Manitoba the 6 inch level from November to March would not be feasible. Additionally, in Manitoba, tile depths are typically 30 to 36 inches rather than 48 inches. These two changes mean that the environmental benefits to controlled drainage in Manitoba will be significantly different from those reported for the Upper Mid-West USA (ADMC 2011).

Table 3-1 Typical Stop Log Operations – Upper Midwest USA (Miller et al. 2012) vs.

Suggested Manitoba Operations

Dates

Traditional Depth of Stop

logs Below Surface

(Inches)1

Manitoba Depth of Stop logs

Below Surface (Inches)2 Comments

November to March 6 36 Could possibly raise during snowmelt

April to Planting 48 36 Adjust after planting

Planting to Pre Harvest 24 24 Could adjust for large rain events

Pre Harvest to October 48 36 Could adjust for manure application 1 After Miller et al. 2015 2 Determined by PBS Water Engineering Ltd. based on 36 inch tile depth

The key factors in determining the feasibility of controlled drainage are slope of the field; which limits the area that can be controlled by the structure. Miller et al. (2012) suggest practical maximum field slopes are about 1%. Based on experience in Manitoba the more likely scenario is slopes of 0.2 – 0.5 %. A major concern is the location of the control structures (see Figure 3-23) which protrude from the ground. In-ground structures have been developed (see Figure 3-24) to overcome this limitation, but these in-ground structures have not been extensively tested in freezing Manitoba conditions.

There is currently no good cost information available for Manitoba conditions. Contractors are able to estimate the incremental cost of controlled drainage, but are typically not actively promoting it as an option. Some of this may still be a function of uncertainty regarding technical feasibility and certainly the other is remaining cost competitive. ADMC (2011) estimated the costs at $65 to $88 per ac ($160 to $217 per ha). Christensen (2012) estimated establishment costs (8 ha field per structure) at $61 to $138 per ac ($150 to $340 per ha). It is not clear that these costs recognize the need for intermediate mains and additional connections to control zones on a field in which laterals are not developed on contours (see Figure 3-22). Typical free drain tile costs range in the $2,500 per ha range in Manitoba (MAWMA pers. comm. 2016). Therefore, it is not inconceivable that control drainage will add 10% to a tile project’s base cost.




Implementation and Operational Considerations

The exact conditions regarding implementation of controlled drainage need to be considered based on design, soil type, crop and other factors, including the tile spacing. Miller et al. (2012) suggest raising stop logs 0 – 20 days after planting and lowering them approximately one to one-half month prior to crop maturity.

The cost to operate is not extreme, if a structured approach (see Table 3-1) is utilized. Some consideration could be given to intermediate settings which recognize the impact of crop growth and a declining water level as evapotranspiration occurs.

A significant concern for manure spreading is during fall periods when soils are already saturated and tiles are running, or when soils are dry and have deep cracks. Operational strategies for these conditions include tillage prior to injection (cracking soils) or avoiding manure injection during saturated or running tile conditions (Section 3.6.7 and Section 4.0). University of Wisconsin Extension (Cooley et al. 2013) recommend the approach highlighted in Figure 3-29. CD structures would allow for this type of control to be established within a field. It should be noted that any control would be temporary if undertaken in the fall, given the pending freezing conditions. It is not clear if this type of delay would be beneficial to nutrient and pathogen loss.

Figure 3-29 UW GWQ064 Fact Sheet No. 3 (2013) Restricting Tile Discharge (Cooley et al. 2013)




Local Design Examples

Three local design examples are available for consideration. University of Manitoba (Cordeiro, 2013) developed controlled drainage research plots at Hespler Farm. Each plot is 0.5 acre and 6 of the 24 plots can be operated for controlled drainage. Canada Manitoba Crop Diversification Center developed 6 controlled drainage plots at their site in Winkler, Manitoba. The site is currently operated by Keystone Vegetable Producers’ Association. University of Manitoba (Dr. Sri Ranjan) has done research at this site regarding nitrogen fate and mobility. Lastly, McKnight Seeds at Homewood developed a controlled drainage layout, reproduced here as Figure 3-30.

Figure 3-30 Bud McKnight Seeds – Controlled Drainage Project – 300 Acres – Homewood Manitoba




Research Gaps

Controlled drainage is an understood, but little adopted practice in Manitoba. Unlike in the USA, in Manitoba, there is no incentive program, including technical support, to the implementation. Also, unlike the USA and Ontario, there has been very little specific research to differing soil and crop types, with respect to design and operational considerations, and anticipated benefits. Lastly, there has been no Manitoba specific research into the capacity to control tile and nutrient flow from manured fields after application during wet conditions or on cracking clay soils subject to subsequent large rainfalls.

Miller et al. (2012) reported studies showing plant uptake of N may be more efficient under controlled drainage (cited Thorp et al. (2008)). To some extent this was verified by Cordeiro (2013) results. Specific studies aimed at quantifying this using existing research sites (e.g., Hespler) would be useful. It could be speculated that this is also a method to utilize untapped N floating in the shallow groundwater table; something which has been observed by AAFC at CMCDC sites (Unpublished data AAFC).

The secondary benefit of controlled drainage is that is can be utilized for subirrigation. While initial research has been done on subirrigation in Manitoba, it was limited to fine sandy loam soils with deep profile and potential lateral water movement (Cordeiro 2013). Additional research is warranted specific to the ability of subirrigation systems to be an effective means of making water available for crop production. This could include one-time spring recharge of the soil to the controlled drainage level; in anticipation of capillary rise during the high evapotranspiration months of July and August and to help to utilize any nutrients previously leached to the shallow water table as part and parcel of a nutrient management strategy.

3.6.2 Bioreactors and Enhanced Bioreactors

Definition

NRCS Standard (747 Interim) describes the practice of woodchip bioreactor treatment for nitrate removal from tile drainage water. Bioreactors can be installed as part of a new project or can be implemented as a retrofit to an existing project.

Nitrates are removed from the drainage water as it flows through the woodchips. The process involves bacteria which use the carbon from the wood chips to breakdown the nitrates in the water to nitrogen gas (Christenson and Helmers 2011, 2012). Woodchip bioreactors are located at the outlet of a tile drainage system, where a portion of the water is diverted through the bioreactor bed using an Agri-Drain stop log control structure (Figure 3-23). Figure 3-31 illustrates a recently installed bioreactor at the Morden Research Station. The photo illustrates the dimensions of a two cell bioreactor (required for research purposes). The woodchips are placed within an impermeable liner and water is diverted to the bed using Agri-Drain structures to control the rate of diversion and the retention time (see Figure 3-32).




The major advantages of the woodchip bioreactor system, include relatively small footprint, standardize design (by climate), little to no maintenance during design life (e.g., 15-20 years), and relatively low and predictable installation costs (Miller et al. 2012). Bioreactors are actively being promoted in Iowa, Minnesota, South Dakota, and portions of North Dakota; all of which are warmer than Manitoba, but are nonetheless geographic neighbors to Manitoba.

Christianson et al. (2012) presented a comprehensive review of design criteria and considerations (e.g., woodchip materials), operational and monitoring strategies for woodchip bioreactor systems. The current NRCS standard is interim, which indicates that the NRCS considers the practice worthy of their financial investment as part of their Drainage Water Management Initiatives (http://www.nrcs.usda.gov/wps/portal/nrcs/list/national/water/ manage/list/?position=Outreach).

Figure 3-31 Woodchip Bioreactor; Containment Geotextile; Agri-Drain Diversion Structure; Morden Research Station

Photo credit: AAFC-Morden

http://www.nrcs.usda.gov/wps/portal/nrcs/list/national/water/%20manage/list/?position=Outreach

http://www.nrcs.usda.gov/wps/portal/nrcs/list/national/water/%20manage/list/?position=Outreach




Figure 3-32 Illustration of Woodchip Bioreactor (Christianson and Helmers 2011)


According to Christianson et al. (2012), nutrient removal rates are influenced by structure design and operations to optimize retention time as well as significantly by the temperature of the tile water. Nitrate removal has been documented are water temperatures as low as 2 to 4 C; which may be relevant to the Manitoba experience since the largest tile flows are in May and June; just after spring thaw when water temperatures are relatively cold.

The structure operation is also sized to only treat the base flow (e.g., 20% of the peak design flow) in order to have more continuous flow conditions and to not create conditions which limit




the effectiveness of the tile for reducing peak water tables in the field.

Christensen and Helmers (2011) report that bioreactors have nitrate nitrogen removal rates varying from 10 to 90%; and have similar anticipated treatment potential to controlled drainage and wetlands (see Figure 3-33).

Figure 3-33 Comparison of Woodchip Bioreactor Nitrate Removal to other Best Management Practices. (Christianson and Helmers 2011)

Recent research, Bock et al. (2015) has examined enhancement of bioreactor water-quality treatment using the addition of Biochar. Initial studies, indicated that P removal of 65% and enhanced nitrate removal, including a reduction in residence time to achieve the enhanced rates. This recent research holds promise for enhanced designs to remove nitrate and phosphorus using bioreactors.


The design criteria for bioreactors in Manitoba conditions are still a work in progress. Ongoing research at the Morden Research Station should provide guidance in this regard. As size of the




bioreactor will be related to anticipated loading and water temperatures, one would expect or anticipate slightly larger bioreactors to be required in Manitoba.

Cost estimates (Christianson and Helmers 2011; Christianson et al. 2013) from experience in the Upper Midwest USA suggest that bioreactors could be priced in the order of $200 to $400 per ha (based on 20 ha sized reactor). There is no doubt some significant economy of scale associated with larger bioreactor sizes or multiple cells at the same site. Christianson and Helmers (2011) suggest total establishment costs of $7,000 to $10,000 for 100 acres (40 ha).


It is recommended that bioreactors be provided with both inlet and outlet control structures capable of adjustment for flow depth. This practice will allow for any operational optimization, and guidelines that may come out of the Morden Research Station bioreactor experiment. Iowa State University has developed a spreadsheet system (Figure 3-34) to assist with design of bioreactors. This spreadsheet would have to be modified to apply to Manitoba conditions.

Figure 3-34 Spreadsheet Design Program – Bioreactors – Iowa State University





The only local design example is the Morden Research Station experimental bioreactor installed on the 100 acre (40 ha) field shown in Figure 3-18. Research results at this site are not yet available.

Research Gaps

The current research gaps in this technology are being addressed by Morden Research Station, AAFC, including efficacy in cold climates, review of design parameters, suitability of local woodchips and % nitrate-nitrogen loading and reduction targets.

In order to gain adoption, demonstration sites, sponsored by the industry and government would go a long way to proving the robustness and applicability of the technology to Manitoba conditions. In the USA, collaboration between producer groups, local watershed authorities, State and Federal agencies, have provided technical and financial incentives for these types of significant demonstration projects. The USDA–NRCS provides a cost share of close to 50% to develop this practice on individual farms.

3.6.3 Saturated Buffers (Vegetated Subsurface Drain Outlet)

Definition

Interim NRCS Standard (739) describes the practice of saturated buffers, also known as vegetated subsurface drain outlet. Saturated buffers can be installed as part of a new project or can be implemented as a retrofit to an existing project.

A saturated buffer involves diverting a portion of the water flowing to the tile drainage outlet and distributing it using perforated tile mains, along a strip of vegetated land parallel to the drain outlet channel or stream. The Agri Drain control structure (Figure 3-23) is utilized to back the water up in the main to allow it to divert to the buffer area, adjacent to the outlet drain/creek (see Figure 3-35).

The practice is premised on water flow through the riparian buffer, removing nitrate nitrogen as it travels to the stream or channel through the saturated ground.

The purpose of the Interim standard, approved in 2012, is to allow for a three-year evaluation period, after which determination will be made to convert to a national standard, or discontinue.




Figure 3-35 Saturated Buffer - Schematic of Diversion, Distribution and Saturated Flow to Stream (Jayne USDA-ARS)

Source: http://web.extension.illinois.edu/iwrc/pdf/presentations/2012/7.%20Biomass%20Crops%20to%20Enhance%20Water%20Quality/3%20Jaynes_Saturated_Buffers.pdf


Dan Jaynes, research scientist for USDA–ARS, in Ames, Iowa has been the lead researcher on the topic of saturated buffers. The USDA-ARS developed the Bear Creek site in 2010 to evaluate the effectiveness of the concept. Leopold Center (2013) reports that 50% of the tile flow over 2010 and 2011 was diverted through the saturated buffer strip, and that 100% of the nitrate-nitrogen was removed.

Miller et al. (2012) presented preliminary data from the Bear Creek Site, revealing the variation in the percentage of flow diverted (see Figure 3-36). Data presented in Miller et al. (2012) suggests that nitrate removal amounted to between 8 to 29 kg per hectare.




Figure 3-36 Bear Creek and Maass Farm Data (Miler et al. 2012) – Flow Diverted as % Total Tile Flow – Data from Dan Jaynes, USDA-ARS


The Interim NRCS standard gives guidance to the investigations required to design a saturated buffer site. Each and every design would be site specific; taking into account, soils, riparian width and gradient, head available (e.g., slope of main); utilities and/or obstacles (e.g., trees).

From first glance it would appear that the saturated buffer may be more relevant to small plots given the length of buffer required; not to mention the geographic and land ownership constraints that are likely to arise.





Where feasible, the concept of the saturated buffer is fairly simple and should require relatively little maintenance or operation. Monitoring would be associated with tracking % flow diverted; judging nitrate removal performance would be more difficult given that the discharge is distributed and potentially diluted (e.g., by rain).


There are no local design examples. The nearest examples are in Minnesota, installed by Agricultural Drainage Management Coalition; results were still incomplete in January 2015.

Research Gaps

The research to date has lacked enough detail to document cause and effect; without knowing the physical and chemical mechanisms one cannot properly design with a reasonable expectation of performance.

Properly instrumented and replicated research is required to understand the variables the control the performance with respect to nutrient removal.

3.6.4 Alternative Surface Inlets

Drainage

Surface inlets are used in certain landscapes and soils to allow isolated accumulations of surface water to enter directly to tiles. Traditional surface inlet solutions include the Hickenbottom style inlet (see Figure 3-37).

Figure 3-37 Hickenbottom Surface Inlet to Tile Drain

(http://www.hickenbottominc.com/)

The direct ingress of ponded water will naturally include all the nutrients and potentially sediment that is associated with the surface water runoff. Newer style inlets have been promoted by the Agri-Drain Corporation, namely the water-quality inlet (see Figure 3-38) which reduce inlet velocities and hence can provide some level of water filtration prior to the tile drains. Other options for reduction of sediment and nutrient ingress are:

• Inverse gravel filters, sometimes referred to as “blind inlets” (see Figure 3-39).

• Dense pattern tile under the depression area.





Figure 3-38 Water Quality Inlet – (www.agridrain.com)

Figure 3-39 Blind Rock Inlet

(http://fyi.uwex.edu/drainage/files/2012/06/Blind-Inlet-Factsheet-2012.pdf)


The benefits of alternative tile intakes are:

• Temporary ponding of water and associated settlement of soil particles.

• Filtering of sediment laden water through the in-ground filter system (blind inlets) or the in-situ soil (dense pattern tile).

• A third benefit not discussed is the use/utility of using geotextile filtered tile in the blind or dense patterned inlets. The standard geotextile will not filter clay soils but can easily filter silt size particles.

Miller et al. (2012) reports a strong body of research supporting the efficacy of the alternative intakes, and in particular the blind/gravel inlets and the dense pattern tile. They report trapping efficiencies of 70 to 100% of sediment associated with surface water.

A more recent paper, Feyereisen et al. (2015), reported on reductions in total suspended sediments (TSS) and phosphorus (P), from replacing open tile inlets with blind or gravel inlets. Seven years data on paired plots in Indiana showed TSS (Total Suspended Sediment) loads reduced from 40 kg/ha-event to 14 kg/ha-event; TP (Total Phosphorus) loads reduced 66% and SRP (Soluble Reactive Phosphorus) loads reduced 50% through the use of blind inlets. Feyereisen et al. (2015) suggest an effective design life exceeds 10 years.

Another benefit of the blind or dense patterned inlets could be a reduction in peak tile flow relative to the open inlet (Miller et al. 2012). Significant progress is being made in Lake Erie basin,





towards adoption of this practice (http://www.farmanddairy.com/news/drainage-innovations-can-improve-lake-erie/173441.html).


Gravel and Blind Inlets

The difference between gravel and blind inlets is the ground cover. Blind inlets have a layer of natural topsoil which can be cultivated through and maintained weed free. Gravel inlets must be mounded slightly above surrounding ground surface and will require additional maintenance to maintain their integrity. The USDA-NRCS has developed guidelines for implementation in certain states. Figure 3-40 is a typical design guideline based on a recent fact sheet. (https://efotg.sc.egov.usda.gov/references/ public/IA/Blind_Inlet_620_FS_2015_07.pdf).

Conservation Practice Standard “Underground Outlet” (USDA-NRCS, 2015) allows the use of blind inlets as a component of the underground outlet system. Design of blind inlets can be facilitated by using one of the standard drawings – IA-1550 and IA-1551 – available on the Iowa NRCS Engineering web page.

((http://fyi.uwex.edu/drainage/files/2012/06/Blind-Inlet-Factsheet-2012.pdf)

Dense Tile Inlets

As an option dense tile alternative inlets can forgo the need for the expense of imported granular materials, relying on in situ soils and a dense pattern of perforated, socked tiles to improve local drainage. USDA-NRCS Standard IA-980 provides guidance in sizing these inlets based on soil infiltration properties.

Figure 3-40 USDA-NRCS Fact Sheet Blind Inlet

http://www.farmanddairy.com/news/drainage-innovations-can-improve-lake-erie/173441.html

http://www.farmanddairy.com/news/drainage-innovations-can-improve-lake-erie/173441.html

https://efotg.sc.egov.usda.gov/references/%20public/IA/Blind_Inlet_620_FS_2015_07.pdf

https://efotg.sc.egov.usda.gov/references/%20public/IA/Blind_Inlet_620_FS_2015_07.pdf




To our knowledge, no cost information has been developed for Manitoba projects, nor has this practice been adopted.


Given the positive performance and reception to this practice elsewhere, there is no reason why this couldn’t become a standard practice for tile drainage in Manitoba, where surface inlets are desired. Choice between the options (i.e., gravel, blind, dense pattern), will likely boil down to cost and local availability of materials.

Operationally, the blind and dense pattern options make more sense with respect to maintenance and reducing impacts on farming operations. However, it is not clear from the literature which of these can filter the water faster, thus maintaining the desired water removal rates.


To our knowledge, there are no local design examples. However, the practice has received substantial attention in nearby Minnesota.

Research Gaps

For Manitoba the research gaps include:

• Efficacy and longevity of blind, rock and dense pattern intakes for a variety of Manitoba soils and geography’s should be studied.

• Design criteria, especially related to filter materials, use of sock tile, and use of in situ materials (for dense tile option).

• Amendments to further reduce SRP (soluble reactive phosphorus); similar to the discussion for bioreactors; but at the inlet end rather than the outlet.

3.6.5 Tile Water Capture and Recycling

Definition and Standard

The recycling of tile water has not been studied in a great detail, although there are case studies and promotional materials from Ohio and Ontario on the potential benefits. For example, Tan et al. (2007) reported on a tile drainage recycling experiment where tile water was captured in a wetland complex and recirculated to the corn and soybean crops during dry summer periods, using subirrigation through the tiles. This system was established in the 1990s and has been featured in recent publications as industry interest in total water management has grown (http://www.drainagecontractor.com/drainage-management-systems/irrigation-and-drainage).

http://www.drainagecontractor.com/drainage-management-systems/irrigation-and-drainage




Dr. Larry Brown (University of Ohio) and Dr. Norm Fausey (USDA/ARS) have studied recycling tile drainage water in northern Ohio. Their system named Wetland Reservoir Subirrigation System (WRSIS) has been studied at three sites, from the years 1997–2006, during which water balances, crop yield and water quality were monitored closely. Significant yield differences were attributed to recycling the tile water back to the crop during the growing season. (http://www.ars.usda.gov/sp2UserFiles/Place/50800000/WRSISfactsheet.pdf)

More recently, a collaborative team comprised of leading researchers and extension specialists from Upper Midwest United States, led by Dr. Matt Helmers (Iowa State University), has been formed to study the concepts, constraints and opportunities for water recycling in an attempt to “transform drainage” into water management (https://www.cals.iastate.edu/news/releases/iowa-state-university-studying-water-storage-benefit-crops-waterways)( https://transformingdrainage.org/practices/drainage-water-recycling/) (see Figure 3-41).

Figure 3-41 Transforming Drainage Research Sites Upper Midwest States – Including 10 Recycling Tile Water Sites

http://www.ars.usda.gov/sp2UserFiles/Place/50800000/WRSISfactsheet.pdf

https://www.cals.iastate.edu/news/releases/iowa-state-university-studying-water-storage-benefit-crops-waterways

https://www.cals.iastate.edu/news/releases/iowa-state-university-studying-water-storage-benefit-crops-waterways

https://transformingdrainage.org/practices/drainage-water-recycling/

https://transformingdrainage.org/practices/drainage-water-recycling/





If tile water is reused, one would anticipate that the nutrients could be recycled to the crop, if proper accounting and nutrient management was employed.

Tan et al. (2007) reported a reduction in nitrate losses by 41% and total dissolved phosphorus by 36% for a controlled drainage/subirrigation system compared to a traditional tile drainage system. Furthermore, during the droughty years of 2001 and 2002, this system was associated with higher corn yields (91% increase 2001) and soybean (49% increase 2002) relative to the traditional tile drainage only system.

Design and Cost Consideration

The basic consideration for tile drainage recycling is the incremental cost of storage and recycling. Recent pump storage projects completed in Southern Manitoba, ranging in size from 150 to 300 acre feet, cost upwards of $2,500 to $3,000 per acre foot of water stored (Shewfelt pers. comm. 2016).

Recycling tile water into these reservoirs is possible if:

• Conditions are such that the reservoir cannot fill (e.g., low spring runoff).

• Room is intentionally left in the reservoir for tile water.

• The tiles actually run or run intermittently between demand for irrigations.

• The tile outlet is convenient to the reservoir.

Given these criteria, the potential to utilize existing pumped storage reservoirs is limited, given that they are largely filled through spring snowmelt and subsequently not utilized until the tile drainage systems stop running. There could be some potential to capture fall tile drainage water to supplant the need for spring filling.

Figure 3-42 La Salle Redboine Conservation District – University of Manitoba – Drainage Water Capture and Recycling Site





The recycling of tile water requires a firm understanding of the potential water yield from the tiles, the volume of water to be stored, the purpose or utility of the water and its economic return, the cost to store and redistribute the water, and the quality of the water to be recycled.

Timing of tile water versus other water sources is a major consideration for re-use of tile water for irrigation. With respect to the recycling of water, nutrient, disease and pesticide loading also require consideration as do salt loading potential build up within the irrigated soil profile.

Currently, in-depth research around these issues is lacking.


One southern Manitoba farm recycles water into two reservoirs, near Morden and Carman. In both cases, spring snowmelt water is also utilized to fill the reservoirs. In one case, all the tile water at that location is recycled. In the other case, only a portion of the tile water is recycled with the remainder pumped to the creek.

The University of Manitoba, in collaboration with the La Salle Redboine Conservation District, is studying the economics, agronomics and water-quality aspects of recycling tile drainage water (see Figure 3-42). Research is ongoing until spring, 2017 (https://galiresearch.files.wordpress.com/2015/07/classen-brochure-final_reducedsize.pdf)

Research Gaps

The widespread adoption of recycling of tile drainage water will require specific and extended hydrologic risk/return studies. These studies will have to take into account the nature of the soils being tile drained, the cropping patterns and nutrient balances, the other options for filling the reservoir; the options and costs for capture and recycling of water.

A logical next step would be employing a model such as DRAINMOD (Skaggs et al. 2012) linked to a surface-water model, to estimate and compare tile water quantities and qualities in comparison to unit runoff volumes, frequencies and harvesting. A model to look at integrated snow, rain and tile water harvesting, in relation to soil and cropping patterns and geography would provide base information required to evaluate the economics of storage and recycling.

Monitoring of existing projects could be stepped up as a means of testing the validity of the models especially where it is known that surface runoff is inadequate or being influenced by large scale tile drainage systems.

https://galiresearch.files.wordpress.com/2015/07/classen-brochure-final_reducedsize.pdf




3.6.6 Constructed Wetlands, Reconstructed Wetlands

Definition and Standard

The USDA-NRCS provides standards for Wetland Creation (658); Wetland Restoration (657); and Wetland Enhancement (659) (USDA-NRCS, 2010). In addition, the USDA-NRCS provides program and design guidance under the Conservation Cover Reserve Program (CCRP) Practice CP39 for constructed wetlands (USDA-NRCS 2011). To our knowledge, Manitoba does not have similar standards.

Constructed wetlands are man-made engineered water storages that mimic the biological processes of natural wetlands. Constructed wetlands have been used in Manitoba to successfully treat runoff from intensive livestock operations (McGarry and Pries 2001). Miller et al. (2012) suggest that if properly designed, constructed wetlands can remove excess nutrients and sediment from inflowing surface (or tile) waters. Crumpton et al. (2012) presented the concept of widespread adoption of constructed wetland systems to reduce nitrate loading to Iowa streams from tile drainage outflow. King et al. (2015) suggested that wetlands have been proposed to reduce P losses from subsurface drainage, but noted a wide variation in performance. Sokais and Tanner (2011) related the performance variability to issues of wetland maturation and design. Christianson and Helmers (2011) presented comparative results for wetlands versus bioreactors as a means of reducing nitrates in tile outflow (Figure 3-32). Cooley et al. (2013) suggested that temperature effects on microbial activity may limit wetland capacity to remove N in colder climates (e.g., Wisconsin). Also they noted the risk that wetlands, if not designed and constructed properly, could increase levels of ammonium N and dissolved and total P in the wetland effluent.

To our knowledge, wetlands have not been utilized in Manitoba for the purposes of treating tile drainage discharge, but their documented performance on similar applications, and in other nearby jurisdictions, suggest that they may be effective. A new initiative in Minnesota is geared to accelerating adoption of measures including constructed wetlands for treating of agricultural runoff from tile drainage (https://www.pca.state.mn.us/sites/default/files/wq-s1-80q.pdf).

Reconstructed wetlands are intended to recover and rehabilitate existing wetlands which have had their hydrology, plant communities or soils modified as a result of drainage or other man made intervention. They differ from constructed wetlands in that their primary purpose may be to recover biodiversity and wildlife habitat. Water treatment may be a secondary benefit that in some cases may be contrary to the primary objective if not managed properly. The location of reconstructed wetlands within the watershed may not be ideally suited to treatment of tile drainage outflow (Crumpton et al. 2006).

https://www.pca.state.mn.us/sites/default/files/wq-s1-80q.pdf





Wetlands can be effective settling basins, if designed and sized relative to the contributing watershed area and the anticipated sediment (total suspended sediment, TSS) loading (Miller et al. 2012). With respect to nutrients, Miller et al. (2012) suggest that wetlands are efficient at converting nitrates to nitrogen gas, if anaerobic conditions prevail. Some promising results have been reported for a 27-acre reconstructed wetland in Nicollet County Minnesota (Site 3) (see Figure 3-43). Christenson and Helmers (2011); concluded that wetlands designed in accordance with Iowa standards would reduce nitrates by between 30 and 55 % (Figure 3-32). Christenson and Helmers (2011) did not consider phosphorus removal. Crumpton et al. (2012), reported on a five-year project, aimed at evaluating the potential for integrating nitrate removing wetlands with in-field technologies in drainage water management (e.g., cover crops, nutrient management and controlled drainage). Crumpton et al. (2012) focused on the Des Moines Lobe in North Central Iowa. Results from calibrated wetland/tile water-quality modelling suggested that nitrate yield reductions could be increased from 26% to 59% depending on the wetland size expressed as a percent of the contributing watershed (e.g., 0.5% to 2.5%) (see Figure 3-44).

Figure 3-43 Nitrate Reduction – Reconstructed Wetland (Site 3); Minnesota Board of Water and Soil Resources (Peterson 2009)




Figure 3-44 Average Observed and Predicted Nitrate – N Export (kg/ha/yr) for the Monitored Watersheds with Different Size Wetlands (Crumpton et al. 2012)

To illustrate the potential regional effects, Crumpton et al. (2006, 2012) completed GIS assessments of nitrogen loading to streams and analyzed strategic locations to intercept the tile drainage water with the highest concentrations on 50% of the Des Moines Lobe area. From their studies they estimated reduction in nitrate export by 34 to 46%. If wetlands were combined with nitrogen fertilizer management, the reduction could be expanded by an additional 9–11 %.

Phosphorus reductions in constructed and reconstructed wetlands are reported to be more variable ranging from reduction to increase in total phosphorus loads (Sukais and Tanner 2011). Typically, the phosphorus reduction is associated with reduction in TSS, which is not typically associated with tile drainage water. Sukais and Tanner (2011) reported that phosphorus export from the wetlands was reduced at best by 33%, and at worst was increased by a factor of 2. Miller et al. (2012) suggest that phosphorus harvesting (e.g., cattails) may be required to maintain the potential for phosphorus uptake by wetland systems.


USDA-NRCS has developed standards for Wetland Restoration (657), Wetland Creation (658) and Wetland Enhancement (659) (USDA-NRCS, 2010). New Zealand has developed a design manual




for guiding wetland treatment of tile drainage outflow (Tanner et al. 2010). In general, wetland design needs to be specific to the nutrient and hydraulic loading that is expected (see Figure 3-45). Miller et al. (2012) indicated that surface flow wetlands were more suited to nitrate removal (see Figure 3-43), whereas subsurface flow wetlands maximize the removal of sediment and particulate phosphorus, through filtration and adsorption processes.

Figure 3-45 Measured (2004-2011) and Modelled Performance of Wetlands in Iowa CREP (Crumpton 2012)

Christenson and Helmers (2011) assumed a wetland size of 1% of drained area, as a mean of the recommended Iowa standard sizing criteria. For Manitoba, this criterion would require a setting aside of 2.6 ha for every section of land (i.e., 259 ha); with an accompanying buffer of approximately 7.4 ha (3:1 approximate); for a total of 10 ha. This amounts to a significant land cost (e.g., $150,000 @ $15,000 per ha); which could be a substantial part of the reason for lack of implementation. Having said that, land values are >$7,000/acre (2011$) in the Des Moines Lobe of Iowa, where Crumpton et al. (2012) are promoting integrated wetland treatment systems. In Iowa, the Conservation Reserve Enhancement Program (CREP) provides financial and technical assistance to landowners to adopt wetland creation, restoration and enhancement (Crumpton et al. 2012). The CREP initiative is a partnership between the US Department of Agriculture (USDA) and the Iowa Department of Land and Water Stewardship; and has been in existence since 2001. As of 2015, 77 sites have been completed and another 18 were in development




(http://www.iowaagriculture.gov/ waterResources/CREP.asp). GIS planning expedited and targeted specific locations for locals to consider.


Farmland values have increased dramatically in Manitoba in the past decade (FCC 2014), with annual increases in 2012, 2013 and 2014 at 25%, 25% and 12 % respectively. Under this pressure, there is little to no incentive to identify and set aside less productive lower lying acres for conversion or re-establishment as wetlands. This is not to say that certain landscapes with existing wetlands, or with potential for wetland re-construction cannot be considered as an alternative.

The other implementation consideration is the custom nature of the design process, which requires careful consideration of factors including site selection, site topography, controls for water depth, organic carbon availability, oxygen levels in water, upstream and downstream impacts. Miller et al. (2012) provide some guidance to hydraulic loading rates that are required to ensure adequate nutrient supply to vegetation while not overloading the system and reducing efficiency. Miller et al. (2012) indicate that denitrification may be limited during the spring runoff period due to higher levels of oxygen rich water; as anaerobic conditions are required for the denitrification process. Consideration could be given to modify the New Zealand standard (Tanner et al. 2010).

Lastly, many tile drainage projects have pumped outlets in Manitoba which could allow for perched wetlands to be constructed downstream of the pumps, providing additional landscape options to gravity wetlands.


With respect to tile drainage there are no local examples of treatment of tile drainage water by wetland systems in Manitoba.

Examples of larger constructed or managed wetland complexes are certainly available, such as Lizard Lake (Pembina Valley Conservation District) or Pellee Lake (Redboine LaSalle Conservation District); although it is doubtful these receive much tile drainage water as they are upland projects.

Research Gaps

In order for this option to gain wide spread consideration research is required to itemize and present loading and design parameters for Manitoba conditions. Research and development is required to establish design standards, and costing tools. For example, characterization of tile water should be based on soil types, salt profiles, cropping and nutrient patterns and history, season (spring, summer, fall) and soil nutrient profiles. This data currently does not exist.

Ideally, demonstration / research projects would be established to verify design parameters and highlight potential and efficacy of wetlands for tile water remediation.

http://www.iowaagriculture.gov/%20waterResources/CREP.asp




Research is required into efficacy of wetland systems for phosphorus removal. Mitch and Fink (2001) reported as much as 59% phosphorus removal using a constructed wetland.

Site selection methods utilized in Iowa, including specific GIS targeting of potential sites, could be provided to Conservation Districts as a means to promote community discussion and interaction of this type of option; as part of Watershed plans (e.g., example of typical watershed management planning - http://www.pvcd.ca/goudney.html ).

3.6.7 Other Beneficial Management Options

There are several additional beneficial management options that time did not permit consideration of. These are listed in no specific order, and briefly commented on.

a. Cover Crops - Special crop producers (e.g., potatoes) often utilize cover crops to protect their soils against wind and water erosion in Manitoba. The benefits of these cover crops on extraction of nutrients and in providing additional fall evapotranspiration (e.g. utilization of applied liquid) should be considered. It is not clear how the existence of cover crops impacts preferential flow, manure application equipment, manure application rates and timing.

b. Two Stage Ditches – Cooley et al. (2013) highlighted the potential for redesigning ditches, to have two stages. The low flow stage associated with tile drainage flow would have a very small channel attached to a wide and shallow overbank area that is designed to increase residence time and biological removal of nutrients (e.g., a linear wetland). The implementation of this type of system would require significant design and expense at the municipal and provincial level. Further study is required to assess applicability to Manitoba.

c. Linear Wetlands – King et al. (2015) highlight the potential to change management of existing ditches, in an attempt to maintain their phosphorus and nitrogen trapping abilities with the watershed. The implementation of this type of system would require significant input and direction from municipalities and Conservation Districts with drainage mandates. Further study is required to assess applicability to Manitoba.

d. Tile Drainage Design Parameters – Miller et al. (2012) highlight the potential to modify tile system designs (other than controlled drainage). Crumpton et al. (2012) also comment on design coefficients for tile drainage as it relates to impact on surface runoff and potential BMPs for Nitrate – N reduction strategies. For example, decreasing tile spacing increases drainage coefficient and reduces surface runoff. Decreasing tile depth (at constant spacing) reduces drainage coefficient and results in less tile drainage effluent, along with associated agro chemicals (i.e., similar to Controlled Drainage). Both of these options have implications in Manitoba, and could have benefits for specific situations (e.g., salt reduction, nitrate reduction, surface runoff and associated flooding reduction). Further study is required to direct options with are economically feasible and have significant benefits to the producer and the environment.

http://www.pvcd.ca/goudney.html


Nutrient Management November 18, 2016


4.0 NUTRIENT MANAGEMENT

Nutrient management pertains to the management of the amount, method, and timing of applications of fertilizers, manure, and other soil amendments (e.g., biosolids, industrial organic effluent). The goal of nutrient management is to optimize yields and economic return while reducing nutrient losses to the environment. Effective nutrient management helps reduce the potential for contamination of surface and groundwater by cropping operations.

4.1 FACTORS AFFECTING NUTRIENT AVAILABILITY IN AND LOSS FROM SOIL

4.1.1 Synthetic Fertilizers vs. Manure as Nutrient Sources

Synthetic fertilizers consist of known, plant available constituents that occur in known proportions in the fertilizer (see Table 4-1). In contrast, nutrient quantity, form and availability in manures depends on multiple factors including livestock type, diet, manure handling system, livestock housing and bedding materials.

While synthetic fertilizers contain nitrogen and phosphorus in forms that are plant-available or can be easily converted to forms taken up by crops, manures contain a substantive proportion of nitrogen and phosphorus in organic form which is not readily available to plants (Hernandez and Schmitt 2012). Most of the nitrogen in manure occurs as either organic nitrogen or ammonium. Following manure application, these forms of nitrogen undergo multiple transformations, which affect the amount of nitrogen available for crop uptake, or losses from the root zone. Soil microorganisms break down organic nitrogen through a process called mineralization, converting organic nitrogen to ammonium, a nitrogen form that is plant-available. Between 25-50% of organic nitrogen in manure is converted to ammonium each year following manure application (Hernandez and Schmitt 2012).

Ammonium is relatively immobile and not subject to loss, and is plant-available. Nitrifying soil organisms convert ammonium to nitrate, which is also available to plants but is mobile and can be lost from the root zone via leaching in medium and coarse-textured soils (Hernandez and Schmitt 2012). If manure is not incorporated following application, ammonium can be lost from the soil through a process called volatilization, which converts ammonium to ammonia. Plant available nitrogen can also be lost from the soil when nitrate is converted to volatile nitrogen compounds through denitrification (particularly in fine-textured soils) and when soil microbes take up inorganic nitrogen for their own needs (a process called immobilization) (Havlin et al. 2005). While the residual effects of manure’s organic nitrogen can have far reaching benefits for crop yields years after manure application, there are environmental hazards associated with the transformations of the residual nitrogen amounts. Following application, the nitrogen from synthetic fertilizers can also undergo transformations described for manure nitrogen, i.e., denitrification, leaching, and immobilization. The differences in manure properties influence how




different manure types compare to synthetic fertilizer. For example, with relatively high inorganic-N compared with other manures, liquid hog and poultry manures (see Table 4-2) compare more favorably with synthetic fertilizers than manures with less inorganic N content. Randall (2003) investigated nutrient and pathogen losses to subsurface tile drainage from swine manure and reported similar crop yields between urea and liquid swine manure. While liquid swine manure was applied at a rate equivalent to 310 lbs/ac of available-N (5,000 gal/ac) while urea fertilizer was applied at a rate of 160 lbs/ac in the study, in the following spring, the manured plots had lower nitrate lost to tile drainage water than the urea-fertilized plots. The significantly lower nitrate-N concentrations in the tile drainage water samples from the manured plots in early June suggested substantial loss of nitrate from the fall-applied hog manure due to denitrification during the wet June period (Randall 2003).

Table 4-1 Common Fertilizers and their Characteristics

Name Nutrient Make-up (Nitrogen-Phosphorus-Potassium) Physical Properties

Fertilizers used primarily as sources of nitrogen:

Anhydrous Ammonia 82-0-0 Compressed gas; high affinity for water; pungent odour; corrosive

Urea 46-0-0 Granular

Polymer Coated Urea (Environmentally Smart Nitrogen)

44-0-0 Granular

Nitrogen Solution (Urea Ammonium Nitrate, UAN)

28-0-0 Solution - 50% of the nitrogen is in the urea form and 50% is in the ammonium nitrate form. Contains 0.79 lb N/litre or 3.57 lb N/imperial gallon

Ammonium Nitrate 34-0-0 Granular, prilled

Fertilizers used primarily as sources of phosphorus:

Monoammonium Phosphate (MAP)

11-52-0; 12-51-0; 10-50-0 Solid, granular, does not absorb moisture during storage, fairly resistant to breakdown during handling.

Diammonium Phosphate (DAP) 18-46-0 Solid, granular

Ammonium Polyphosphate Solution (APP)

10-34-0 Liquid - contains 0.31 lb N and 1.06 lb P2O5/litre or 1.42 lb N and 4.83 lb P2O5/imperial gallon

Phosphoric Acid 0-54-0 Liquid - contains 1.87 lb P2O5/litre or 8.50 lb P2O5/imperial gallon

Triple Super Phosphate 0-45-0 Solid, granular

Source: (Manitoba Soil Fertility Advisory Committee 2007).




Manure contains inorganic phosphorus which may behave similarly to phosphate fertilizers, as well as organically-bound phosphate at various stages of breakdown whose availability is affected by other manure constituents, e.g., aluminum, iron, or calcium (Hedley and McLaughlin 2005). The fate of organic phosphorus in soils depends on factors affecting mineralization by micro-organisms (similar to organic nitrogen), as well as the soil physical and chemical factors which influence the solubility of both organic and inorganic phosphorus compounds (Hedley and McLaughlin 2005). The behaviour of manure phosphorus in soil is largely influenced by reactions of inorganic phosphorus which is mainly found in the solid phase of manure (Gerritse and Vriesema 1984) as cited in Hedley and McLaughlin (2005). As much as 80% of the phosphorus in manure can be available for plant uptake in the first year (Hernandez and Schmitt 2012).

Leaching losses of phosphorus can occur following the application of synthetic fertilizers or manure. Leaching of phosphorus is influenced by soils characteristics (e.g., low phosphorus sorption capacity, presence of macropores), agronomic management practices (e.g., amount and forms of phosphorus added) and climatic conditions (e.g., precipitation greatly exceeding evapotranspiration) (Gburek et al. 2005). Phosphorus immobilization by microorganisms and sorption onto soil particles are considered temporary or transfer pathways, instead of losses since they can be reversed with mineralization or desorption.

Given the differences in nutrient forms and availability between synthetic fertilizers and manure, the use of synthetic fertilizers allows prescriptive application of nitrogen and phosphorus whereas with manure these constituents are variable and have to decide to apply based on nitrogen or phosphorus crop needs or by most limiting factor.

4.1.2 Manure Properties

The amounts of manure nitrogen and phosphorus that are available to crops primarily depend on the characteristics of the manure, as well as the time that the manure is applied and how soon following application the manure is incorporated into the soil. Manure from different farming systems contains varying proportions of organic and ammonium-N. Generally, liquid manure contains a higher proportion ammonium-N than solid manure (see Table 4-2). Following land application, ammonium-N may be converted to nitrate-N , taken up by crops or lost via leaching, denitrification or temporarily lost for plant uptake if immobilized by soil microbes. Manure phosphorus primarily comes from feces (Table 4-3) and generally occurs in higher concentrations in solid than liquid manure fractions.




Table 4-2 Ammonium Nitrogen Contents of Various Manure Types

Type Ammonium-N Content (%)

Liquid hog 66

Liquid dairy 42

Liquid beef 43

Liquid poultry 67

Solid hog 26

Solid dairy 21

Solid beef (high bedding) 12

Solid horse 15

Solid poultry (broilers) 6

Solid poultry (layers) 46

Composted cattle 0.6

Notes: Source: NMAN software, OMAFRA 2009

Table 4-3 Distribution of Excreted Phosphorus in Feces and Urine for Different Livestock

Livestock Type Total Phosphorus Excreted (%)

Feces Urine

Cattle 97.3 2.7

Sheep 93.8 6.2

Swine 83.1 16.9

Source: Azevedo and Stout 1974)

4.1.3 Soil Properties

Soil properties affecting the availability and transport of nutrients in the soil include texture, organic matter content, moisture content, soil pH, soil temperature and soil nutrient levels (Comerford 2005; Sims and Sharpley 2005). Compared to natural drainage, tile drains increase infiltration, which reduces runoff and associated nutrient losses, while simultaneously creating an additional flow path of potentially nutrient-laden water, which often drains directly into surface waters (Ball Coelho et al. 2012a).

Generally, higher soil moisture results in higher crop yields at comparable nitrogen supply levels, and a larger response to applied fertilizer or manure (Manitoba Soil Fertility Advisory Committee 2007). However, under flooded or saturated soil conditions, soil bacteria convert nitrate-N to




nitrogen gas (N2O) through denitrification, reducing the amount of nitrogen for crop uptake and creating environmental concern through losses of nitrogen to the atmosphere (N2O is a potent greenhouse gas). Volatilization losses of applied ammonia-nitrogen are favoured by moist soil conditions, high soil pH and high levels of free lime or calcium carbonate (Manitoba Soil Fertility Advisory Committee 2007). Coarse textured soils (with moisture holding limitations; agricultural capability subclass M); soils with shallow bedrock (agricultural capability subclass R) or soils with a combination of the preceding properties are susceptible to leaching of nutrients, particularly nitrate-N, which can impact the underlying groundwater (MAFRI 2008). The potential for nitrate leaching is enhanced under conditions where there is high residual nitrogen concentration in the soil following harvest.

While coarse textured-soils (e.g., sands) allow more rapid infiltration of rainfall, irrigated water or liquid manure, fine-textured soils (e.g., clays) have slower infiltration and hydraulic conductivity. However, macropores formed due to soil organism activity (also referred to as biopores, e.g., roots, worm burrows) and cracks or fissures, can cause rapid movement of nitrogen and phosphorus from applied manure or fertilizer, and bypassing of the soil matrix which presents a tortuous pathway for nutrient movement. Macropores are generally considered to have an equivalent pore diameter of greater than 0.001 mm (Fleming and Bradshaw 1992). The occurrence of macropores on tile-drained lands can create a direct link between the field surface and tile lines resulting in large nutrient losses (called preferential flow) (Jensen et al. 1998; Stamm et al. 1998; Simard et al. 2000; Lawrence et al. 2011). Phosphorus sorption capacity of finer-textured soils is much greater than that of sandy or organic soils. However, the potential for development of preferential flow paths in finely textured soils appears to be an important driver of subsurface phosphorus losses. The effect of macropores on nutrient loss from the soil to tile drains is enhanced by crop irrigation, storm and snowmelt events that provide a transport medium for applied manure or fertilizer at the surface.

Loss of phosphorus from soil has largely been associated with surface runoff because of the way the nutrient adsorbs to fine sediments; abundance of nutrients in surface soil horizons; and increased soil erodibility (Sims and Sharpley 2005; King et al. 2015). With the installation of subsurface drains, surface runoff and sediment loss are generally reduced (Dolezal et al. 2001), resulting in lower losses of phosphorus via surface runoff. However, tile drains have been reported as a potentially significant source of phosphorus in agricultural watersheds (Sims and Sharpley 2005).

4.1.4 Weather Conditions

Immediately following the application of manure or urea-containing fertilizers to a field, ammonium-N is lost as ammonia due to volatilization. This process continues until the manure is moved into the soil by incorporation or rainfall or until the ammonium in the manure is depleted to the point that it is stable (OMAFRA 2009). Manures that are incorporated soon after application will provide much more nitrogen to the crop than manure that is not incorporated. Volatilization losses of applied nitrogen are promoted by higher temperatures (Manitoba Soil




Fertility Advisory Committee 2007).

Precipitation amount and intensity affects nutrient loss from soils (Bolton 1970; Ulen 1994; Dils and Heathwaite 1999; Frey et al. 2013). Early-season moisture and late-year precipitation are important drivers for nitrate loss to groundwater because of the absence of crop nutrient uptake at these times coupled with rising water tables (Harland et al. 1997). Ball Coelho et al. (2012a) found snow-melting events to be the main driver of nitrogen loading via both overland and tile drain pathways to surface water. In Manitoba and other similar cold, dry regions, snowmelt nutrient export is the main factor affecting nutrient export and with nutrients occurring in dissolved- rather than sediment form (Tiessen et al. 2010). The concentrations of soluble reactive phosphorus and total phosphorus in tile effluent are typically low during base-flow (background conditions) but increase during storm events (Dils and Heathwaite 1999). Bolton (1970) conducted a field study on nutrient losses through tile drains under three cropping systems and two fertility levels on a clay loam soil and found the amount of water flowing through the soil to be the predominant factor influencing nutrient loss. Frey et al. (2013) reported the largest movement of total nitrogen and total phosphorus to tile drains to be triggered by the first rain event following liquid swine manure application to a poorly drained, clay loam soil in eastern Ontario.

Weather conditions also affect the forms of nutrients lost from the soil. Under snowmelt, flowing water leads to erosion whereas during a rainfall event, erosion occurs due to both detachment by raindrop impact and transport by runoff. As a result, there is more nitrate-nitrogen and soluble-phosphorus than sediment-associated nitrogen and phosphorus in snowmelt than in growing season runoff, which in turn has more sediment-associated nitrogen and phosphorus (Ball Coelho et al. 2012a; Ball Coelho et al. 2012b).

4.2 BENEFICIAL MANAGEMENT PRACTICES FOR NUTRIENT MANAGEMENT

Nutrient management is the collective of producer practices that seek to supply nutrients in adequate quantities to sustain maximum crop productivity and profitability while minimizing associated environmental impacts of nutrient use (Havlin et al. 2005). It hinges on the principles of nutrient source, rate of application, time of application and placement or method of application.

4.2.1 Determining the Right Nutrient Source

Determining the right nutrient source is a unique process for each operation and is driven by multiple factors including economics, type of operation, size of operation, soil properties, crop types and yield goals. For example, a mixed livestock and cropping operation may prefer the use of manure as a nutrient source due to availability and to ensure continued availability of manure storage capacity. On the other hand, for a high-value cropping operation, fertilizers may be preferable since they allow prescriptive nutrient application, can be better matched with target crop yields and can often be applied during seeding operations. Because of the




readily available nature of fertilizer nutrients, timing, placement and rate aspects should be carefully considered to achieve optimum use of fertilizer nutrients while reducing the potential for nutrient losses via leaching, volatilization, and denitrification (Havlin et al. 2005).

The application of livestock manure on cropland utilizes nutrients and organic matter in the manure to enhance soil fertility and tilth, while allowing producers continued availability of manure storage facilities (Pappas et al. 2008). Compared to synthetic fertilizer which has a known composition, manure can provide more nutrient types. However, unlike fertilizers, manure’s nutrient content is variable and its nutrients may not be as readily available for plant uptake. Manure nutrient content also depends of multiple factors including animal species, diet, and manure storage method (Miller et al. 2012). Organic forms of nitrogen and phosphorus will have to undergo mineralization to be available for crop uptake (Havlin et al. 2005). Given phosphorus’ slower reaction, mobility and tendency to accumulate in soil compared to nitrogen, historical nutrient applications should be considered when selecting a nutrient source for an operation. Coppi (2012) and Tenuta et al. (2013) reported substantial phosphate accumulation but little ammonium and nitrate accumulation in a gravelly sand soil at a site in La Broquerie, Manitoba, that had received repeated annual pig slurry applications to grassed hay fields and pasture. There is no economic advantage of adding phosphorus to fields that have an Olsen test phosphorus result of at least 16 ppm (University of Minnesota Extension 2002). Utilization of manure as a nutrient source therefore requires an understanding of the manure nutrient status and potential nutrient transformations that could occur, to determine the amount of nutrient that will become available to the crop.

Tan et al. (2015) compared the impact of three optional nutrient management regimes and two drainage scenarios. Synthetic fertilizer, liquid cattle manure and solid cattle manure were compared; under free drainage and controlled drainage systems. During the four year study, 800 kg N per ha of nitrogen were added to each plot. The cumulative nitrogen losses for the six treatments can be summarized as follows:

Application rate: 200 kg N ha-1

Cumulative application in 4 years = 4 x 200 = 800 kg

Total export in 4 years (runoff + tile) – Free Drainage

Synthetic fertilizer 13 + 135 = 148 kg N ha-1

Liquid cattle manure 15 + 80 = 95 kg N ha-1

Solid cattle manure 32 + 98 = 130 kg N ha-1

Total loss by treatment (%) – Free Drainage

Synthetic fertilizer 148/800 = 18.5 %




Liquid cattle manure 95/800 = 11.9 %

Solid cattle manure 130/800 = 16.2 %

The study also indicated that controlled drainage increased losses due to surface runoff but reduced losses through the tile drainage system.

Hao et al. (2015), studied the application of three forms of manure, namely liquid manure, solid manure and liquid manure compost in comparison to commercial fertilizer and impact on phosphorus uptake and crop yield. They concluded that the form-based P source agronomic coefficients are needed to optimize P utilization efficiency. P utilization is important in controlling losses to the environment.

4.2.2 Application Rate

According to Hernandez and Schmitt (2012), the steps to be followed in determining a sustainable application rate for manure are:

(i) Establishing nutrient needs of the crop;

(ii) Manure testing to determine the manure’s nutrient content;

(iii) Determining quantities of nutrients assumed to be available in the first growing season (i.e., nutrient availability factor); and

(iv) Calculating the rate of application using the nutrient availability factor and nutrient amount needed by the crop.

Crop nutrient budgeting, recent yields, soil productivity, climatic conditions, level of management, nutrient costs, expected return are all factors used in selecting an application rate (Miller et al. 2012). BMPs focused on nutrient application rate include:

• Developing and maintaining operation-specific nutrient management plans to guide sustainable decisions regarding nutrient sources (Manitoba Soil Fertility Advisory Committee 2007; Hernandez and Schmitt 2012).

- Determine fertilizer application rates taking into consideration crop needs and soil test recommendations for fertilizer rates.

- A reduction in nitrogen fertilizer rates from applied rates to those recommended on the basis of maximum return for nitrogen could reduce nitrate exports from the Des Moines Lobe by some 18% (Crumpton et. al. 2012). In this same study, tile flow was noted to account for approximately 90% of water yield from the studied watersheds which is the reason that tile water quality is so vitally important to the overall stream water quality in this area. Crumpton et al. (2012) concluded that a targeted wetland restoration program in conjunction with nitrogen rate management has the potential to reduce nitrate export by 45-55%.




• Collecting manure samples regularly for laboratory analysis presents a good basis for manure application rates since the nutrient content of manure is highly variable, even for the same operation and livestock type. Using variable rate fertilizer application or precision agriculture technology to optimize nutrient use efficiency and reduce loss through recognition of in-field variation due to soil type, organic matter content and water holding capacity (Miller et al. 2012).

• Using precision agriculture technology can assist with getting more accurate application rates for manure.

- John Deere (https://www.deere.ca/en_INT/our_company/news_and_media/ press_releases/2015/aug/connected-fields.page) released a new manure sensing application in 2013, which is supported by near infrared technology.

- The John Deere technology is said to allow producers to make on-the-fly adjustments to rate of nitrogen, ammonium, phosphate, potassium and dry matter through a combination of tractor speed and flow control. It can also be utilized to leverage precision mapping of the need for addition of mineral fertilizer, as it provides an accurate representation of the manure constituents as applied.

- Manitoba companies have geared up to providing topographic, texture, and salt mapping of fields, nutrient management prescriptions and manure management planning (http://www.krcropcheck.com/soil-testing-and-veris.htm l; http://www.farmersedge.ca/precision-solutions/ ).

• Using phosphorus-based manure application rates since crop phosphorus needs are typically exceeded when manure is applied to meet crop nitrogen needs and to conform to regulatory requirements.

- Section 13 of the Livestock Manure and Mortalities Management Regulation (133/2008) (see Section 1.2.4), provides guidance on phosphorus-based manure management planning where soil test phosphorus exceeds 60 ppm (Olsen method).

o Supplemental fertilizer can be used to make up for the additional nitrogen required. There appears to be a general lack of reported specific studies on manure applied to meet only phosphorus needs and supplemented (in spring) with commercial nitrogen fertilizer.

• Growing a cover crop, seeded in the fall and grown through the winter, to reduce the amount of nitrate available for leaching (Ulen 1995). While cover crops are uncommon in Manitoba and their application as a BMP may be limited, they may provide some value as a companion BMP under controlled drainage systems.

http://www.krcropcheck.com/soil-testing-and-veris.htm

http://www.farmersedge.ca/precision-solutions/




4.2.3 Timing of Application

The timing of fertilizer or manure application influences the nutrient transformations that occur in the soil and ultimately affects the quantities of nutrients available for crop uptake or lost from the root zone via runoff, leaching, volatilization, and denitrification. Table 4-4 shows nitrogen fertilizer efficiency as a function of timing and method of application. BMPs focused on timing of nutrient application include:

• Applying synthetic fertilizers in the spring offers the best nutrient use efficiency.

- Fall application of manure or fertilizers allows producers enough time to work in their fields as well as more time for mineralization of organic nutrients before crop uptake compared to spring application. Spring fertilizer application can increase risk of soil compaction especially when coupled with extended rainy conditions. Fertilizer is also cheaper in the fall (Miller et al. 2012). However, fall application also provides more time for potential loss of nitrogen (Randall and Vetsch 2005).

- If fall application is most practical, application late in the fall is recommended because early in the fall can be associated with temperatures warm enough for significant nitrification and potential for loss of nitrate by leaching or denitrification later in the fall or spring.

- Randall and Vetsch (2005) reported greater fertilizer nitrate losses under fall than spring application timing for urea fertilizer. They also found that use of a nitrification inhibitor to retard conversion of ammonium in urea to nitrate is more beneficial with fall than spring application.

- Hernandez-Ramirez et al. (2011) found that compared to the fall, moving liquid-manure application to the spring resulted in the reduction of leaching of nitrates to tile drains by 30%; making it similar to spring applied commercial fertilizer.

- Randall and Mulla (2011), showed that spring application of N and lower rates resulted in reduced Nitrate N loss to drainage water (see Figure 4-1). They also noted that tile drainage water quality can also be significantly impacted by the high organic matter content of some soils, and their ability to mineralize N. Bolton et al. (1976) concluded that high nitrate levels in tile drainage was specifically related to the amount of fertilizer used in a specific crop rotation (e.g., continuous corn).




Figure 4-1 Effect of N Rate and Time of Application on Nitrate N Losses (Randall and Mulla 2001)

• Applying manure in late fall or spring, or implementing split manure applications.

- Spring application of manure has the least amount of time for nitrogen loss potential. However, rapid mineralization of manure organic nitrogen in the spring may cause short-term nitrogen imbalances in the soil due to immobilization of inorganic nitrogen.

- Waiting to apply all manure in the spring can result in delayed field operations and planting making late fall application more favourable.

- Tile drainage flows are typically more frequent in the spring then the fall, due to the summer drawdown of the shallow water table.

In Manitoba, where manure is typically applied in the fall, split applications in the fall and spring could better match crop demand with nutrient availability and help reduce environmental losses (Coppi 2012).

- Several publications (Hoorman et al. 2005; Cooley et al. 2013; Harrigan et al. 2015) recommended reviewing soil conditions prior to liquid manure application in order to assess the risk for tile drainage interception of the manure application and practicing a split application approach for manure. Soils that are near field capacity (water) and soils that have significant cracking or macropores, are recommended for reduced “volumes” of liquid manure to prevent leaching of the liquid manure, which can make its’ way directly to the tiles. Outstanding nutrient requirements can then be applied as manure or fertilizer at another time. In practice Harrigan et al. (2015) has found little issue with rates of 6000 gallons/acre or less.

- Cooley et al. (2013) recognized the benefits of split application and recommends waiting to apply fall manure until soil temperatures are less than 50 F; to reduce the potential for




nitrification of ammonia.

• Not applying manure during winter.

- Winter manure application is least favorable, especially for Manitoba conditions, because with snow on the ground, incorporation of manure is not possible, and with manure left on the surface, the potential for nutrient losses in runoff during snowmelt is enhanced.

- Winter application of manure is restricted in Manitoba from November 10 to April 10 of the following year as per the Livestock Manure and Mortalities Management Regulation (M.R. 42/98).

• Taking weather conditions and forecast into consideration when planning manure or fertilizer application to reduce the potential for nutrient losses.

- Within the chosen season of manure application, attention should be paid to weather forecast to reduce the chances of fertilizer or manure application occurring immediately before a major rainfall event. Findings from a study investigating nutrient and bacteria transport to tile drains in free drainage plots and controlled drainage plots indicated that the majority of nutrient and bacteria transmission occurred during the hydrologic response to the first post-manure application rain event (Frey et al. 2013).

- Observe soil moisture in relation to field capacity and the level of the shallow groundwater relative to the tile elevation to judge potential for tiles to activate.

• Following recommendations for fertilizer application rates or applying only enough nutrients to meet crop needs.

• Implementing fertigation where land is under irrigation and split application to match crop nutrient needs and reduce the amount of nutrient susceptible to loss (Manitoba Soil Fertility Advisory Committee (2007).

4.2.4 Application Method and Placement

The placement method used for fertilizer or manure application affects nutrient availability for crop uptake; nutrient loss via leaching, denitrification or volatilization; and ultimately crop yields and producer economic returns. While manures are typically applied in the fall or in the spring prior to seeding via broadcasting or injection, synthetic fertilizers have more options for placement method. Banding fertilizer (8-15 cm deep) has become a common method for nitrogen fertilizer application (Alberta Agriculture and Forestry 2001). Banding provides producers with the opportunity to apply their nitrogen fertilizers in the fall when they have more available time for field operations and when they can take advantage of fertilizer price discounts. However, since banding results in relatively nitrogen-concentrated pockets in the soil, banded fertilizer can be a source of enhanced nitrogen losses through denitrification under wet soil




conditions (e.g., during and soon after spring thaw, conditions that are applicable to Manitoba). Banding placement options that can be considered include pre-plant band, side band or mid-row band at planting, and seed row placement (Manitoba Soil Fertility Advisory Committee 2007; Alberta Agriculture and Forestry 2001). The relative efficiencies of the various placement methods for nitrogen fertilizers depends on multiple factors including crop type, soil properties, climatic conditions, type of fertilizer, row spacing and spread of seed and fertilizer (Alberta Agriculture and Forestry 2001). Table 4-4 shows the relative efficiencies for nitrogen fertilizers in increasing crop yield as a function of placement method and timing of application.

Unlike nitrogen fertilizer which is readily soluble and mobile when applied, phosphorus is less mobile and gets fixed in high pH soils, such as those in Manitoba (Manitoba Soil Fertility Advisory Committee 2007), reducing the plant-available phosphorus in soil. As a result, the placement of phosphorus fertilizer plays an important role in the amount of phosphorus available to plants, crop quality and yields. Fertilizer phosphorus use efficiency is highest with placement which limits soil contact with fertilizer, for example, banding, and when fertilizer is applied with seed. Compared to banding, broadcast and incorporated phosphate results in the lower yield increase per unit of P fertilizer. However, high rates of phosphorus fertilizer can adversely affect crops, e.g., flax. This can be averted by application of phosphorus at rates just sufficient to meet crop needs.

The addition of tile drainage to a field complicates the placement decisions. Smith et al. (2015) indicated that in their research fields, located in the Maumee basin in Ohio, 49% of soluble P and 48% of total P losses occurred via tile discharge. Cooley et al. (2013) noted that preferential flow can intercept liquid manure placed by traditional sweep and knife injection systems; transporting manure directly to tiles. Frey et al. (2013) also noted rapid transmittal of liquid manure to tiles, under the specific conditions of their study. In the Frey et al. (2013) study it was noted that the short term increase in tile flows, due to the manure application, was generally low and losses of nutrients and bacteria were “minimal”.

Beneficial management practices focused on the method of application and placement include:

• Broadcasting followed by incorporation of solid manures and synthetic fertilizers within a few days to reduce volatilization losses of nitrogen and promote mineralization of organic nitrogen (Manitoba Soil Fertility Advisory Committee 2007; Hernandez and Schmitt 2012).




• Injecting liquid manures (e.g., hog and dairy) reduces odour and volatilization nitrogen losses (see Figure 4-2).

Figure 4-2 Liquid Manure Injection System in Manitoba

• Miller et al. (2012) recommend incorporation for liquid manure with soluble P content as a means to reduce P losses due to surface runoff. There is a trade off with surface disturbance which may exacerbate surface movement of P.

- Injection of liquid manure with chisel-type knives could create conditions that favor denitrification. However, the associated denitrification losses are much less than the volatilization losses that occur when the liquid manure is left on the surface (Hernandez and Schmitt 2012). Compared to chisel-type knives, sweep knife injection systems reduce denitrification potential (see Table 2-1).

- Cooley et al. (2013) indicated that knife and sweep injection systems can exacerbate liquid manure movement to tiles (via macro pores); either through lack of adequate pre-tillage, proximity of sweeps or pulling the implement too fast creating a plunger effect with the soil.

• Subsurface banding of nitrogen and phosphorus fertilizers reduces volatilization losses of nitrogen and enhances crop phosphorus-use efficiency (Manitoba Soil Fertility Advisory Committee 2007).




• Using inhibitors to delay the processes of volatilization and nitrification following application of fertilizer

- Agrotain, a urease inhibitor, will delay volatilization from urea and UAN solutions for up to 14 days (Manitoba Soil Fertility Advisory Committee 2007).

• Developing site specific plans based on observation and monitoring of tile outlets during and after manure placement to ensure the manure management plan is working (Harrigan et al. (2015). Monitor and adjust as required.

Table 4-4 The Relative Effectiveness of Nitrogen Fertilizer by Application Method and

Timing

• Method and time of application

Soil-climatic categories1

Average values2 1 2 3 4

Dry3 Medium Wet4 Irrigated

Spring broadcast and incorporated 100 100 100 100 100

Spring banded 120 110 105 110 120

Fall broadcast and incorporated1 90 75 65 95 80

Fall banded 120 110 85 110 100

Notes: 1 Source: Alberta Agriculture and Forestry (2001). 2 Source: Manitoba Soil Fertility Advisory Committee (2007). 3 Although spring and fall banded nitrogen were equally effective in research trials, fall banding may be more practical under farm conditions. The extra tillage associated with spring banding may dry the seedbed and reduce yields. 4 In research trials conducted in the higher rainfall areas, spring broadcast nitrogen was well incorporated and seeding and packing completed within a short period of time. Under farm conditions, shallow incorporation or loss of seedbed moisture resulting from deeper incorporation may cause spring broadcasting to be somewhat less effective than shown here.

Table 4-5 Nitrogen Availability in Manure and Loss as Affected by Livestock Type and Manure Application Method

Animal Species and Year of Application2

Surface Broadcast and Incorporation Timing1 Injection

None <4 days <12 hours Sweep Knife

% Total N

Beef

Year 1 25 45 60 60 50

Year 2 25 25 25 25 25

Lost3 40 20 5 5 10




Table 4-5 Nitrogen Availability in Manure and Loss as Affected by Livestock Type and Manure Application Method

Animal Species and Year of Application2

Surface Broadcast and Incorporation Timing1 Injection

None <4 days <12 hours Sweep Knife

% Total N

Dairy

Year 1 20 40 55 55 50

Year 2 25 25 25 25 25

Lost3 40 20 10 5 10

Swine

Year 1 35 55 75 80 70

Year 2 15 15 15 15 15

Lost3 50 30 10 5 15

Poultry

Year 1 45 55 70 NA NA

Year 2 25 25 25 NA NA

Lost3 30 20 5 NA NA

Notes: 1 The categories refer to the length of time between manure application and incorporation. 2 Third-year available N can be calculated by adding Year 1 and Year 2 and lost percentages and subtracting this sum from 100. 3 Lost refers to estimated volatilization and denitrification processes. Source: Hernandez and Schmitt 2012

4.2.5 Preferential Flow

Nutrient loss through preferential flow is most likely to be an issue if manure is being spread within about 10 feet to either side of subsurface drainage lines and tiles are running (Lawrence et al. 2011). Extension specialists in several states (Harrigan et al. 2015) have utilized smoke bombs (into the tile) to illustrate the presence and persistence of preferential flow paths at ground surface. Indications are that the direct surfaces to tile paths are limited to an area directly above the tile and to a distance either side. Tillage directly over the tile lines has been suggested to break up these paths (King et al. 2015). While manure application directly over tile lines could be avoided where the location of underlying tiles is known, this approach may not be practical for several reasons (e.g. uniformity of fertility). Fluid viscosity is an important factor for flow and transport in macroporous soil. Modeling results have shown that increasing liquid manure viscosity during the application of liquid manure reduces nutrient movement to tile drains in the days following application (Frey et al. 2012). Manure with greater than 5% solids has a reduced tendency to access preferential flow paths (Cooley et al. 2013).




BMPs that can be adopted to reduce the potential for preferential nutrient and pathogen transport from the surface to tile are:

• Avoiding application of manure when tiles are actively flowing and monitor tile outflow during spreading events (Lawrence et al. 2011).

• Increasing soil-manure contact at application through manure incorporation or through the installation of water table control technologies (Lawrence et al. 2011). Incorporation of manure soon after application also reduces nitrogen losses as ammonia through volatilization and reduces odour.

• Tilling fields to break up preferential flow pathways and mix manure with the soil.

- For minimum or reduced till systems, an aerator can be used to achieve shallow incorporation with less soil disturbance than conventional tillage (Lawrence) et al. 2011).

- Several extension publications (Harrigan et al. 2007; Hoorman et al. 2009; Cooley et al. 2013) recommend tillage to break up preferential flow paths prior to, or concurrently with manure application.

- Cooley et al. (2013) recommended that soils should be tilled to at least three inches below the depth of manure injection.

- Harrigan (2015) suggested that injection with the Aerway SSD Precision Manure Application System has worked well for them, although no direct research results were presented. This system is also being utilized in Manitoba by some producers (see Figure 4-3). The nature of the equipment will dictate how even a distribution and actual application rate of liquid manure.

- Hoorman et al. (2009) indicate an effective application rate of 50,000 gallons per acre; for a nominal 10,000 gallon per acre liquid manure applied through an injection toolbar with 6 inch sweeps and 30 inch spacing. If this more intensive application takes place directly above the tile drain, where preferential flow is maximized, one would anticipate higher leaching rates.




Figure 4-3 Manure Injection System – Aerway SSD Precision Manure Application System (Manitoba)

- For liquid manure application in a tile-drained field (lateral tile spacing of ∼60 ft.) prone to macropores, broadcast application preceded by tillage resulted in lower nitrogen losses to the tile drains compared to application by a narrow-tooth injector to a depth of 15 mm (Fleming and Bradshaw 1992). While the till followed by broadcast application approach might reduce nitrogen losses via tile drains versus injection, the former method would likely be associated with greater volatilization losses offsetting its credit.

• Applying manure under good weather conditions and as close to crop uptake as practical to enhance crop nutrient use efficiency and reduce potential for nutrient loss under inclement weather.

• Agitating liquid manures prior to application to create uniform viscosity during application. Modeling studies have shown that increasing the viscosity of liquid manure reduces nutrient movement to tile drains in macroporous soil (Frey et al. 2012). Liquid manure with greater than 5% solids can reduce the potential for preferential flow to tiles (Cooley et al. 2013).

• Using approaches to remove phosphorus from tile discharge at the tile outlet, e.g., lining drainage ditches with gypsum, inserting a highly absorptive material directly into the tile line, and use of external “end-of-pipe” filters (Lawrence et al. 2011).

4.2.6 Research Gaps for Nutrient Management of Manure on Tiled Lands

The relationship of the 4R’s to manure management on tile-drained land has received little attention in Manitoba. Building on research findings in other jurisdictions, namely, Minnesota,




Wisconsin, Ohio and Ontario, and adjusting for Manitoba’s climate (e.g., frozen soils); will require intelligently designed research programs.

Questions to be asked and answered would pertain to:

• Best methods to characterize manure (i.e., source) for manure management planning for tiled lands; could involve testing protocols, in field monitoring equipment, etc.

• Best timing of manure application (by type) relative to nutrient and pathogen loss through tiles, with special attention to soil type, soil moisture, manure rates. with specific consideration of split application of manure in the fall and synthetic fertilizer in the spring.

• Best rate of manure application (by type) relative to nutrient and pathogen loss through tiles. Miller et al. (2012) recommended research into incremental nitrogen application rates relative to tile nitrate loads in Minnesota.

• Best method of manure application (by type) relative to nutrient and pathogen loss through tiles, taking into consideration preferential flow paths, equipment options, tillage, surface flow and nutrient transport, cropping systems, etc.

In addition, extension materials such as University of Wisconsin Fact Sheet No. 3 (Cooley et al. 2013) are urgently required in Manitoba for education of producers, local residents and government officials (e.g., Manitoba Agriculture, Sustainable Development). These extension materials should be accompanied by field and classroom training and education series (e.g., Harrigan et al. 2015) and may be developed by provincial agencies, university departments, industry organizations, consulting companies or cooperative working groups comprised of various organizations.


Pathogen Loss from Agricultural Fields Receiving Manure November 18, 2016


5.0 PATHOGEN LOSS FROM AGRICULTURAL FIELDS RECEIVING MANURE

Livestock manures contain a wide range of microorganisms, namely bacteria, viruses and protozoa. Bacteria known to be human pathogens include E. coli, Salmonella spp., Listeria, Streptococcus spp., Campylobacter, Clostridium spp., while protozoa known to be human pathogens include Giardia and Cryptosporidium (OMAFRA n.d.; Sobsey et al. n.d.). The levels of pathogens in manure vary and depend on livestock type. While generic E. coli can be found in the manure from all species, E. coli 0157:H7 is most common in cattle; Salmonella is most commonly found in poultry manure; Campylobacter is common in poultry manure and Cryptosporidium are common in cattle manure (OMAFRA n.d).

5.1 FACTORS AFFECTING PATHOGEN TRANSPORT

Soil properties (e.g., texture, nutrient levels, organic matter content) and environmental variables (e.g., moisture, temperature and freezing and thawing) affect pathogen densities in soil.

The application of manure can improve the viability of pathogens in soil due to increased manure nutrient availability and moisture. Freitas et al. (2003) showed that the decomposition of the organic matter in liquid hog manure was rapid and used as a source of energy, nutrients and biomass production by soil microorganisms. Holley et al. (2005), found significantly greater survival of Salmonella in treatments containing manure slurry.

Regardless of temperature or sampling times, Holley et al. (2005) found salmonella to survive significantly (p≤0.05) better in clay loam than in sandy loam soil, likely due to the finer-textured soil’s higher organic matter content and moisture compared. Generally, fine-textured soils with a relatively higher water holding capacity (e.g., clay loams) exhibit higher microbial survival by providing a source of water for microorganisms over a longer period compared to the coarser-textured soils.

The occurrence of macropores in soil due to roots, soil organisms’ burrowing or cracks can cause the rapid transport of manure-derived pathogens through the soil profile. On tiled lands, the presence of macropores has been found to magnify the populations of pathogenic microorganisms in the tiles following liquid manure or biosolids application (Natsch et al. 1996; Lapen et al. 2008; Frey et al. 2013), indicating the movement of bacteria from these nutrient sources via preferential flow.

Following manure application, the persistence of manure pathogens in soil is affected by soil type, moisture, pH, temperature, and organic matter as well as sunlight. Pathogen characteristics, particularly winter survival rates, influence the potential for their detection in subsurface drains (Pappas et al. 2008). The survival time of bacteria in soil ranges from a few




hours to more than a year depending soil texture, moisture and temperature (see Table 5-1).

Table 5-1 Survival Times of Some Bacteria in Soil

Bacteria Soil Type of Manure Moisture Temp. (°C) Survival Reference

Streptococci loam - - - 9 - 11 weeks

Feachem et al. (1980)

Streptococci sandy loam - - - 5 - 6 weeks

S. typhi various soils - - - 2 days - 400 days

Bovine tubercule bacilli

soil Cow dung - - less than 178 days

Leptospires varied - varied summer 12 hours - 15 days

Salmonella sp. sandy loam

and clay loam

Cattle slurry - summer 30 days Nicholson et

al. (2005)

Salmonella Sandy loam

and clay loam

Pig slurry 60% and 80% of field capacity

summer-winter simulation

more than 180 days

Holley et al. 2005

While Hutchinson et al. (2004) reported that pathogens in soil decline at similar rates regardless of season, Holley et al. (2005) demonstrated that summer-winter temperature regimen provided a larger Salmonella reduction in soils during the first month compared to the spring-summer temperature, from a study simulating Manitoba temperature conditions with pig-slurry amended soils. Holley et al. (2005) inferred that fall temperatures would prolong Salmonella survival in manure-amended soils and that freeze-thaw cycles occurring from the fall to spring would shorten the survival of Salmonella.

5.2 BENEFICIAL MANAGEMENT PRACTICES TO REDUCE PATHOGEN TRANSPORT

While a greater extent of pathogen transfer from manured land is through runoff to surface waters, pathogen transport via tiles or preferential flow pathways can contaminate groundwater as well (Spiehs and Goyal 2007). Manure management approaches such as anaerobic storage, composting, aeration, anaerobic digestion and chemical treatment reduce pathogens in livestock manure (Krieger et al. 1975; Kearney et al. 1993; Watkins et al. 1996; Oeschner and Doll 2000) and in so doing form a line of defense for pathogen transport before manure is land-applied (Spiehs and Goyal 2007). Management of other livestock-related aspects like diet and diet modifications have also been reported to reduce pathogens in manure (Muralidhara et al. 1977; Zhao et al. 1998; Nisbet et al. 1999; Ohya et al. 2000; Ebner and Mathew 2000; Byrd et al. 2001; van der Wolf et al. 2001). However, the current study focused on




BMPs at the field-level to reduce the risk of pathogen transfer when manure is land-applied. Adoption of practices that reduce nutrient transport to tiles also reduces potential for pathogens transport.

5.2.1 Application Timing and Rate

In the absence of firm guidance on timing of manure application, storage limitations often predominantly influence the timing of manure application (Pappas et al. 2008). Manure application rate correlates positively with indicator organisms for pathogenic viruses (Gessel et al. 2004). The following practices are beneficial for sustainable manure application and reducing pathogen transmission from manure to soil:

• Avoiding manure application during winter months when the ground is frozen and likelihood of manure runoff into nearby waters during spring snowmelt is higher (Spiehs and Goyal 2007; Pappas et. al 2008).

- Low temperatures enhance the potential for pathogen survival in manure and soil, magnifying the risk of transport of viable pathogens in surface runoff from winter-applied manure (Guan and Holley 2003).

- In Manitoba, manure application is restricted from November 10, through the winter, until after April 10. By upholding this regulation, producers will be adopting this BMP.

• Basing manure application rates on soil and manure testing results as well as next crop nutrient requirements.

• Applying manure at rates that match crop uptake is vital for reducing the potential for pathogens transport through runoff or via tiles.

- Significantly higher Enterococci densities were found in subsurface drain water when manure application rate was increased from 168 kg N ha-1 to 336 kg N ha-1 (Pappas et al. 2008).

- Applying manure at higher application rates than those needed by crops results in greater quantities of pathogens available for leaching.

• Calibrating manure-application equipment prior to application of manure and applying manure at rates recommended for crop nutrient needs (Spiehs and Goyal 2007).

- The application of manure at higher rates than those required by crops has resulted in higher levels of indicator pathogenic organisms relative to soils not receiving manure (Hutchison et al. 2004).




5.2.2 Application Method

Manure application method differs among livestock types and forms, with broadcasting or surface spreading typically used for solid manures (e.g., cattle, poultry) and injection typically used for manures with relatively higher moisture contents (e.g., dairy, hog). BMPs focused on reducing the transport of pathogens in fields receiving manure include:

• Incorporating solid manure soon after spreading, to reduce the potential for pathogen transport through pathogen runoff.

- However, given the potential for pathogen desiccation and exposure to detrimental action of sunlight at the soil surface (via manure broadcasting), the incorporation of manure may help preserve the viability of pathogens (Hutchinson et al. 2004; Gessel et al. 2004).

- Fall injection of liquid manures disturbs macropores and results in lower pathogen densities than late winter broadcasting of manure (Pappas et al. 2008).

5.2.3 Controlled Tile Drainage

Tile drains present a pathway for applied manure pathogens to contaminate ground or surface water (Natsch et al. 1996; Lapen et al. 2008; Frey et al. 2013). Frey et al. (2013) found rapid movement of E. coli to free draining tiles following application of liquid swine manure to a poorly drained, macroporous, clay loam soil. However, compared to free tile drainage, controlled tile drainage has been found to reduce the occurrence of some pathogens, e.g., Salmonella spp. and Arcobacter spp. in the watershed (Wilkes et al. 2014).


Synthesis of Findings November 18, 2016


6.0 SYNTHESIS OF FINDINGS

The installation of subsurface drainage systems, generally through the use of tile drains, on agricultural land offers agronomic and economic as well as environmental benefits for agricultural producers. The use of tile drainage in agricultural fields affects the hydrology and hydrogeology, that is the way water moves across the surface of the land and through the soil after it infiltrates. Simply stated, relative to the undrained condition, tile drainage shifts water movement from surface runoff to internal drainage via vertical and lateral drainage of free or gravitational water from the saturated zone if that zone is located at or above the depth of the tile. This results in positive benefits including earlier access to the land following spring melt for land preparation and seeding, more uniform drying and faster warming of the soils (Hill 1976; Harland et al. 1997; Mahoney et al. 2011; MAFRD n.d.1). Despite these positive benefits, tiles are a known source of excess nitrates and in certain instances, dissolved and particulate phosphorus as well. Conceptually, the implementation of tile drainage reduces the pathway of nutrient and pathogen loss from an agricultural field via surface runoff but introduces a new mechanism for entry of such into surface water via concentrated tile outflow while influencing the entry of constituents into groundwater systems. There has been less research conducted on pathogen entry into tile compared with the body of knowledge regarding nutrients, however, Spiehs and Goyal (2007) note that while a greater extent of pathogen transfer from manured land is through runoff to surface waters, pathogen transport via tiles or preferential flow pathways can contaminate groundwater as well.

With tile drainage acres increasing in Manitoba (and other jurisdictions in Canada and the US), as producers attempt to improve productivity of their land and manage risk associated with excess water, concern over the environmental impacts of this management approach has grown, as has the focus on determining management practices to reduce these impacts. In Manitoba, this has manifested a recent ruling by a Rural Municipality to prohibit the application of animal manures on lands which are tile drained.

The effectiveness of BMPs to reduce nutrient losses from fields is influenced by the likely primary nutrient transport pathways and the timing of nutrient movement from specific systems. Deciding on the appropriateness of nutrient management BMPs for an operation depends on various factors including soil type, crop, nutrient source, and land management practices like tillage, soil conservation, and drainage improvements. Because beneficial nutrient management practices need to be customized to each operation or field, there is no “one size fits all” design.

6.1 NUTRIENT AND PATHOGEN TRANSPORT ON TILE DRAINED LANDS

Tile drainage changes the hydrology of water flow within an agricultural landscape. Mathematical modelling on soils in the Red River Valley indicates that as the drainage coefficient increases, surface water runoff decreases, tile drainage outflow increases, crop yield increases, and overall water yield (tile outflow and runoff) increases slightly (Sands 2013). Tile




design will affect drainage coefficient; deeper and more closely spaced tiles will result in a higher drainage coefficient, and “stopping up” the tiles to a prescribed depth (e.g., controlled drainage) will result in a lower drainage coefficient. Implementation of controlled drainage (CD) can result in increased surface water runoff when compared to uncontrolled or free tile drainage (FD) (Crumpton et al. 2012), unless tile spacing is adjusted (Satchithanantham 2013). As flow shifts from surface runoff to tile outflow, downstream water quality will change. Generally, surface runoff has higher phosphorus and particulate in it, while tile drainage water has higher nitrate and salts. The general case is associated with matrix flow through the soil’s natural pore spaces, and is a function of soil saturation and shallow groundwater levels. Preferential flow paths can develop in soils, associated in particular with cracking clay soils, or soils with extensive macropores. Under preferential flow, phosphorus and pathogens are more likely to show up in tile water. Tillage tends to reduce conditions favourable to preferential flow.

Other subtle changes can affect tile water quality. The presence of surface inlets results in higher concentrations of phosphorus in tile drains relative to drainage systems without surface inlets (King et al. 2015). Compared to shallow placement of tiles, deep placement of tiles reduces phosphorus concentrations but increases phosphorus load (King et al. 2015). Soil salt levels existing as a result of near surface evapotranspiration of saline water, may dissipate to a degree after installation of tiles (AAFC unpublished data). The soluble salts are transferred downstream in the drainage water.

The implications of tile drainage for manure application are the same as for all farming operations; close reconsideration of standard management practices is needed to optimize the tile benefit while reducing the potential for adverse environmental effects. Special considerations for manure management include:

• Potential for direct flow of liquid manure to tiles in soils with significant macropores or in soils with high soil water content (near field capacity) around the time of application.

• Potential for decreased surface runoff due to increased infiltration, allowing for additional tillage (i.e., prior to manure application to disrupt macropore network).

• Additional management options not available to undrained conditions (e.g., controlled drainage, edge of field treatments) to deal with water-quality issues directly and proactively.

• Capability to monitor a large part of the field runoff water quality directly at the tile outlet and the ability to measure the impact of these BMPs directly at the tile outlet.

Compared to synthetic fertilizers, manure can potentially pose a greater risk of phosphorus leaching to tile drains (King et al. 2015), but regardless of nutrient source (manure or fertilizer), the potential for phosphorus and nitrogen losses to subsurface drains:

• increases with increasing levels of soil test nutrient concentrations;

• increases with increasing nutrient application rate;




• decreases with broadcast application followed by incorporation vs. broadcasting alone;

• increases with antecedent soil moisture content;

• Increases when tiles are flowing at the time of application; and

• can increase when there is precipitation soon after manure or fertilizer application depending on soil moisture status.

While fine-textured soils have a relatively higher capacity to sorb phosphorus than coarse-textured soils, nutrient loss in fine-textured soils can be greater due to preferential flow (King et al. 2015). A high water table on controlled tile-drained land can increase concentrations of phosphorus in tile flow (King et al. 2015), which poses an issue for fall nutrient application if tiles are “stopped up”. Fields receiving high manure application rates, under no till or with perennial cropping present a greater risk of phosphorus loss than those under annual cropping and conventional tillage (King et al. 2015). The presence of macropores in soils that are tile drained has been found to magnify the populations of pathogenic microorganisms in the tiles following liquid manure or biosolids application (Natsch et al. 1996; Lapen et al. 2008; Frey et al. 2013) indicating the movement of bacteria from these nutrient sources via preferential flow. Additional tillage during manure applications can act to disrupt the connectivity of the macropore network, and reduce preferential flow of water and associated nutrients and pathogens following application of manure amendments. Following manure application, the persistence of manure pathogens in soil is affected by soil type, moisture, pH, temperature, and organic matter as well as sunlight (when surface applied). Pathogen characteristics, particularly winter survival rates, influence the potential for their detection in subsurface drains (Pappas et al. 2008).

The variable nature of manure properties requires diligence in understanding favourable timing and method of application and ramifications of application rates relative to soil residual nutrient content, potential crop usage and potential losses via surface runoff and transit to tile through preferential flow or movement through the soil matrix.

If handled properly the net impact of tile drainage on water quality could become a net positive. Some have suggested combining BMPs (e.g., wetlands) with increased tile drainage intensity as a means of reducing agriculture’s net impact on downstream water quality (Crumpton et al. 2012).

A cautionary approach needs to be identified with respect to influence of hydrogeology on tile drainage and vice-versa. The major concern for water quality in aquifers arises from the potential of downstream discharge to “cross” paths with aquifer recharge areas. Tile drainage companies in Manitoba are increasingly taking advantage of professional hydro-geologic services to avoid these problems, as well as to avoid the interception of artesian waters (Oosterveen pers. comm. 2016).




The sustainability of tile drainage, with or without manure application, will be a function of a holistic approach with application of a suite of BMPs tailored to the specifics of the farmer’s field(s), the soil and cropping regime and the climate we operate in (King et al. 2015).

6.2 BENEFICIAL MANAGEMENT PRACTICES FOR TILED LANDS RECEIVING MANURE APPLICATION

Beneficial Management Practices (BMPs) for tile drainage have been researched extensively in the Midwest USA and in Ontario by Agriculture and Agri-Food Canada. The target of these Best Management Practices has been to reduce off-site movement of agrochemicals, improve efficiency of use of inputs for crop production, and understanding production benefits of selected in-field BMPs.

Given the existence of BMP research, this study was commissioned to examine the suitability of selected BMPs for adoption in Manitoba. Consideration was given to availability of standard design practices, efficacy for improving water quality, operation and maintenance issues, and identification of current Manitoba examples where these BMPs have been successfully adopted.

The following sub sections address the BMPs considered within the scope of this study.

6.2.1 Controlled Drainage

Controlled Drainage (CD) is the practice of creating water table management “zones” within the tile drainage design and installation. Typically, these zones include land within an elevation increment of 1–1.5 foot. Controls (e.g., Agri-Drains) are used to “stop-up” the water after planting in order to capture additional moisture for crop uptake. As a result, controlled drainage has potential in Manitoba to provide additional moisture for crop production, in relationship to typical free drainage (FD) systems.

In many geographic locations, the environmental benefits attributed to CD systems in comparison to FD systems are significantly related to overwinter reduction in tile flows. This benefit does not exist in Manitoba due to frozen soil conditions, and hence the benefit of CD is reduced here relative to results reported for USA and Eastern Canada research studies.

Manitoba research on fine sandy loam soils, confirms the benefits of controlled drainage on reduction of total nutrient loading and tile water outflows (Cordeiro 2013; Satchithanantham 2013). Surface runoff can however be increased according to US-based modelling results, to an extent negating some of the benefits of CD (Crumpton et al. 2012). Nonetheless, Ontario researchers have shown the benefits of controlled drainage in the Canadian context, including the reduction of nitrate loading from the application of liquid and solid manure to tiled lands relative to free draining tiles (Tan et al. 2015).

Consideration to using controlled drainage during manure application, may be tempting due to the potential to “shut down” tile flows. In practice, the total blocking of tiles could result in




surface ponding of water/manure on downslope portions of fields (Shewfelt pers. comm. 2016). Ontario researchers determined that controlled drainage may provide avenues for liquid manure to access lateral preferential flow paths, at least during initial application. Controlled drainage was shown to significantly reduce pathogen transport in research fields in Ontario (Frey et al. 2013).

Manitoba has only two full scale controlled drainage projects. Neither project has been studied in great detail, with respect to efficacy, operational issues, and producer satisfaction. To date, adoption of controlled drainage in Manitoba is very limited, and is not being actively promoted. This is contrary to the USA where, for example, the USDA-NRCS actively promotes CD.

It is estimated that controlled drainage could add 10% to a tile drainage project cost.

6.2.2 Bioreactors

Bioreactors are engineered in-ground structures, which can provide water treatment to a portion of the tile flow. Bioreactors have the advantage of having little impact of tile flow rate and water levels in the drained field. Bioreactors are being promoted in the USA where they have been noted to reduce nitrate loading by nearly 40% (Christenson and Helmers 2011). The USDA-NRCS has developed an interim standard for this practice.

Researchers at AAFC, Morden, have installed a bioreactor to treat a 100-acre field. Research results are promising (Zoski pers. comm. 2015) but have as yet not been published.

Research into amendments to bioreactors for the purpose of phosphorus removal has accelerated (Bock et al. 2015) concurrently with the understanding that phosphorus is indeed carried by tile drains, under preferential flow conditions (Smith et al. 2015). Bioreactor amendments such as biochar appear to have promise, but more research, design and testing is required.

The benefit of bioreactors as a BMP is their small footprint, predictable costs, standardized design and operations, leading to their potential to be a relatively affordable and robust technology (e.g., land, design, construction).

There are no local examples of bioreactors at the producer scale and no adoption of this promising technology in Manitoba to date.

6.2.3 Saturated Buffers

Saturated buffers have been first proposed by the USDA-ARS (Agricultural Research Service), as a means to treat a portion of the tile drainage water by diverting it to create a zone of saturated soil adjacent to the stream or waterway that the tile is discharging to. Saturated Buffers are being promoted in the USA where they have been noted to reduce nitrate loading by nearly 50%.




The research on saturated buffers is fairly scant. The uniqueness of each buffer zone, namely the soils, vegetation and hydrogeology will make design guidelines more difficult, and prediction of benefits less certain. Since the design involves limited structures and only additional tile materials, it is simple in construction and could be implemented by the tile industry. Unfortunately, unlike bioreactors which discharge to a single point, saturated buffer performance would be hard to monitor from an operational standpoint, as say part of a manure management plan.

The literature reviewed does not report on the impact of saturated buffers on phosphorus or pathogens.

There are no local examples of saturated buffers at the producer scale and no adoption of this technology in Manitoba to date. The USDA-NRCS has developed an interim standard for this practice, to guide implementation in the USA.

6.2.4 Alternative Surface Inlets

Traditional open surface inlets deliver surface runoff water from trapped topographic depressions directly to tile drainage systems. They are widely utilized in certain locals and watersheds (Smith et al. 2015), particularly in more hummocky landscapes and tighter soils (e.g., clay soils). Consequently, traditional surface inlets deliver all the constituents in surface runoff directly to tiles, including manure byproducts.

Alternative surface inlets filter the surface water prior to entering the tile system. Blind inlets utilize graded sand and gravel filters to remove significant portions of TSS and associated particulate phosphorus and reportedly remove dissolved phosphorus as well. Reported removal rates exceed 65%. The studies reviewed did not comment on the use of surface inlets to treat incoming water for removal of nitrates or pathogens.

To date in Manitoba, tile installers report very few installations of open inlets (MAWMA pers. comm. 2016).

There are no local examples of alternative surface inlets at the producer scale and no adoption of this technology in Manitoba to date.

6.2.5 Tile Water Recycling

Water recycling has recently become a consideration in the USA, especially in States where semi-arid conditions may exist. Researchers in Ohio and Ontario have for some time researched small scale “looped” systems involving controlled drainage, water capture and recycling and subirrigation (Brown et al. 1998). More recently, USA researchers are looking to recycling water as a strategy to add resilience to Midwest farms against swings of weather from dry to wet.

In Manitoba, tile water recycling has been practiced at two locations from as early as the mid – 1990s in the Morden-Carman area. More recently, research has begun to look at recycling surface and tile water in the Red River valley.




The largest draw backs to recycling water will be the additional cost of storage (e.g.$2,500 per acre-foot); the need for water security (e.g., tiles don’t run in a dry spring); and the impact of the tile water quality (e.g., salts, agrochemicals, pathogens, nutrients) on water, soil, plant and human health.

The local producer scale examples have not been studied in detail. The research on the Red River Valley storage option continues, but results were unavailable to date. Mathematical modelling (e.g., DRAINMOD) has potential to provide answers to the water security questions.

6.2.6 Constructed and Reconstructed Wetlands

Targeted constructed wetlands have been utilized extensively in Iowa to intercept and treat tile drainage effluent for the purposes of reduction of nitrate levels in receiving waters. Modelling studies in Iowa reveal that nitrate reductions of up to 55% are possible with a combination of targeted wetlands and nitrogen management (Crumpton et al. 2012).

Wetland design is complex, as are their operations and maintenance. Design standards have been developed by the USDA–NRCS for constructed wetlands. New Zealand has developed a wetland design manual that could potentially be adopted and modified for Manitoba. Iowa uses a rule of thumb that the wetland area must be between 0.5 and 2.0% of the drained area to be effective.

Concerns with constructed wetlands include land, design and construction costs; project siting and variable performance for removal of P. This study did not review the research on the impact of constructed wetlands on bacteria in the watershed. Monitoring of wetland performance is possible.

There are no local examples of constructed wetlands for treatment of tile drainage water at the producer scale and no adoption of this technology in Manitoba to date.

6.2.7 Nutrient Management

Nutrient Management holds significant promise for mitigating concerns with nutrient and pathogen transport to tiles. The principles of 4R – Right Source, Right Rate, Right Time and Right Place all have application to manure management for tile lands. Nitrogen management has been shown to have potential to reduce tile Nitrate N loading by 15% or more (Crumpton et al. 2012). Management of nitrogen could include reduced rates, split applications, inhibitors, soil testing, real time manure monitoring/injection systems, and variable rate technologies including mapping. Shallow groundwater nitrate levels could be taken into account in nutrient budgets, considering the role of the water table in crop growth in Manitoba (Ayers et al. 2006; Cordeiro 2013).

The manure form and source dictates the nutrient value, the presence of pathogens, the volume of liquid, and consequently the impact on soil moisture conditions (and leaching).




Manure treatments may reduce pathogens (e.g., composting) or liquid amounts; both of which can lead to reduced potential for off-site contamination.

The manure application rate must account for unbalanced nutrients in manure relative to plant needs and be implemented on the most critical nutrient for environmental protection. Commercial fertilizer may be required to supplement plant needs. This gives rise to the opportunity for split applications. Soil moisture as a percentage of field capacity may dictate liquid manure application rates, in order to prevent leaching. Equipment designed to distribute manure uniformly across the field, and new technology capable of variable manure nutrient application rates both show promise for improving nutrient uniformity. The potential for “tile avoidance” using GPS technology appears to be on the horizon (King et al. 2015). However this may create other agronomic challenges to producers (e.g., impracticality associated with equipment width relative to tile spacings, inconsistent nutrient application within the field).

The timing of manure application is a function of the manure constituents, and in particular the liquid volume, and the ratio of organic to ammonium N. Soil temperature plays a role in nitrification and hence potential for phosphorus leaching (Miller et al. 2012). Precedent climate conditions will influence surficial soil conditions (e.g., soil moisture, soil cracking, shallow water table, tile flow) and future climate conditions (e.g., frost, precipitation) can be expected to interact with the applied manure and the application conditions (e.g., placement).

The application of liquid manure has largely been by injection in Manitoba. The addition of tile drainage complicates the impacts of this method, as it was meant to reduce surface flow and odor; but may increase access to preferential flow to tiles. Pre- or post-application tillage, uniformity of application (i.e. equipment design), smaller or split applications of liquid manure, are all methods of keeping the manure in the soil and out of the tile.

Manure management on tiled lands must be tailored to the individual field, cropping rotation, equipment, soils, hydrogeology and tile drainage design. The test of a proper manure management “system” for tiled lands is the monitoring of the tile outflow quality and the adjustment of the management “system” to achieve the desired water-quality goals or target reductions (Cooley et al. 2013; Harrigan et al. 2015). Monitoring of the tile should include periodic inspection of all physical components, including laterals, surface inlets, outlets and mains, to ensure all maintained in good and functioning shape.

6.2.8 Other Beneficial Management Practices

Future considerations could be given to cover crops, as a means to utilize residual moisture and nutrients after harvest. Issues to consider would be increase to preferential flow, manure application equipment compatibility, suitable crops and crop rotations, net benefits to nutrient capture and release, impact on spring infiltration and runoff. While cover crops are uncommon in Manitoba and their application as a BMP may be limited, they may provide some value as a companion BMP under controlled drainage systems.




Future consideration could be given to two stage ditches and/or linear wetlands, as means to transport and teat tile effluent within modified linear drainage systems. Issues to consider would include cost of new ditching, ditch maintenance, ditch capacities (for flooding) land access and costs, and efficacy over time for N and P removal. Reduction of flood flows due to tile could be factored into the studies.

Future consideration of tile drainage design could include more site/field/crop specific designs with respect to depth and spacing, area avoidance (e.g., overtop aquifers), in relation to potential for nutrient and water transport and as they may affect other design elements (e.g. CD, Bioreactors, etc.).

6.3 KNOWLEDGE GAPS

6.3.1 Beneficial Management Practices Knowledge Gaps

The knowledge gaps for Beneficial Management Practices in Manitoba fall into several broad categories. These gaps could be parsed into significantly greater detail as required.

a. Beneficial practices for manure management on soils under tile drainage to reduce nutrient and pathogen movement via preferential flow and through the soil matrix, including application rates, split applications, tillage and tile “avoidance”.

b. Nutrient and pathogen losses and loading to tile and surface waters for a variety of soil types, manure forms, cropping “systems”, application methods, tile designs (controlled and uncontrolled, depth, spacing).

c. Efficacy of edge of field treatments (bioreactors, saturated buffers, wetlands) for nitrate reduction in Manitoba tile conditions, and modifications to treat for phosphorus and pathogens.

Design and cost of BMPs specific to Manitoba conditions, including accounting for anticipated nutrient and pathogen loading from Manitoba based cropping, nutrient management, soils and climate(s).

6.3.2 Tile and Ancillary Structure – Investigation and Design

The design of tile drainage systems in Manitoba is relatively generic, assuming ¼ inch drainage coefficient, 2.5- to 3-foot depth and 50-foot spacing regardless of geographic constraints, hydrogeology, downstream considerations, crop or soil type. While some consideration is given to the impact of tile on downstream hydrology (Shewfelt pers. comm. 2016), little consideration is given to water quality.




Considerations that could improve confidence in system performance both on and off the farm are:

a. Develop and extend economic and design alternatives, guidelines and methods for controlled drainage, free drainage and water recycling options. This could involve significant mathematical modelling involving Manitoba climate and soils.

b. Regional hydrogeologic investigations aimed at delineating actual risk areas within specific municipalities (e.g., North Portage, Interlake, etc.). This step could include the development of project specific investigation guidelines and risk assessment protocols.

c. Interim design guidelines or standards for edge of field treatments (wetlands, bioreactors, saturated buffers) for Manitoba conditions.

6.4 RECOMMENDATIONS FOR FUTURE RESEARCH AND DEVELOPMENT NEEDS

6.4.1 Beneficial Management Practices Research Recommendations

The research recommendations for Beneficial Management Practices in Manitoba are as follows:

a. Replicated trials on nutrient and pathogen losses and subsequent loading to tile and surface waters for a variety of soil types, manure forms, cropping “systems”, application methods, tile designs and nutrient management plans.

b. Replicated trials and demonstration sites to prove the efficacy of edge of field treatments (bioreactors, saturated buffers, wetlands) for nitrate reduction in Manitoba tile conditions (soils, crops, climate, nutrients), and modifications to treat for phosphorus and pathogens.

c. Economic and engineering research and development into the cost of BMPs specific to Manitoba conditions, including anticipated nutrient and pathogen loading from Manitoba based cropping options, soils and climates.

d. Further research on tile design options (free drainage, controlled drainage, drainage depth, drainage coefficient, water recycling) making use of mathematical models (e.g., DRAINMOD; Skaggs et al. 2012) to consider extended weather records, typical soils (e.g. clayey, loamy, sandy) and hydrogeologic scenarios (e.g. lateral flow). This modelling would serve two purposes. Firstly, it would provide information on potential environmental impacts of these design options. Secondly, it would provide producers and designers with data to base risk/cost decisions on spacing vs. crop yield and potentially on downstream loading.

e. Development and identification of soil-landscape constraints (e.g., soils, slopes, topography, hydrogeology) to adoption of specific BMPs.




6.4.2 Extension, Education and Training Materials

Public and producer education remains a critical element of dealing with manure management on tile drained lands. Even though questions and answers on impacts and mitigation have a level of uncertainty, risks should be communicated as well as options to deal with them. Fact sheets such as the University of Wisconsin Fact Sheet 3 (Cooley et al. 2013), provide an excellent basis for moving forward. Key messages that could be communicated:

a. Each field is unique combination of tile design, soils, geology, cropping, manure source, nutrient levels and beneficial management planning options.

b. Performance measured selection of BMPs starts with appropriate nutrient and pathogen management.

c. Special considerations should be given to cracking clay soils and soils with extensive macro pores.

d. Performance can be measured at the tile outlet; and as such progressive measures should be allowed for, including multiple BMPs needed to attain water-quality objectives.

e. Uncertainties in existing BMP options.

The industry (MAWMA pers. comm. 2015) has also prioritized the development of a Manitoba Tile Drainage Manual. The purpose of the manual would be to establish standards, which could be agreed to and abided by tile installation companies, and to provide a standardized document to inform producer and public education.


References November 18, 2016


7.0 REFERENCES

ADMC. 2011. “Drainage Water Management for Midwestern Row Crop Agriculture”. NRCS Conservation Innovation Grant 63- 3A75-6-116, Final Report.

Alberta Agriculture and Forestry. 2001. Fertilizer Application and Placement. Available online at: http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex621#table6 (accessed on April 29, 2016).

Ale, S., Bowling, L.C., Brouder, S.M., Frankenberger, J.R., & Youssef, M.A. 2009. “Simulated Effect of Drainage Water Management Operational Strategy on Hydrology and Crop Yield for Drummer Soil in the Midwestern United States”. Agricultural Water Management, 96, 653-665.

Ayers, J.E., Christen, E.W., Soppe, R.W.O, and Meyer, W.S. 2006. “Resource Potential of Shallow Groundwater for Crop Water Use; A Review”. Irrigation Science 24:147-160.

Azevedo, J., P.R. Stout. 1974. Farm animal manures: an overview of their role in the agricultural environment. Manual 44- Calif. Agric. Exp. Stn. And Ext. Serv.

Betcher, B., Grove, G., Pupp, C. 1995. “Groundwater in Manitoba; Hydrogeology, Quality Concerns, and Management”. NHRI Contribution CS-93017, Saskatoon, SK. http://manitoba.ca/waterstewardship/reports/groundwater/hg_of_manitoba.pdf.

Bock, E., N. Smith, M. Rogers, B. Coleman, M. Reiter, B. Benham, and Z.M. Easton. 2015. “Enhanced Nitrate and Phosphate Removal in a Denitrifying Bioreactor with Biochar”. J. Environ. Qual. 44:605–613. doi:10.2134/jeq2014-03.0111.

Bolton E.F., J.W. Aylesworth and F.R. Hore. 1970. Nutrient losses through tile drains under three cropping systems and two fertility levels on a Brookston clay soil. Can. J. Soil Sci. 50:275-279.

Brown, L.C., Czartoski, B.J., Fausey, N.R., and H.W. Belcher. 1998. Integrating constructed wetlands, water supply reservoirs, and subirrigation into a high yield potential corn and soybean production system. In: Drainage in the 21st Century: Food Production and the Environment. Proceedings of the 7th Annual Drainage Symposium, Orlando FL, Mar 8-10. pp 523-529. ASAE, St. Joseph, MI.

Byrd, J.A., B.M. Hargis, D.J. Cadwell, R.H. Bailey, K.L. Herron, J.L. McReynolds, R.L. Brewer, R.C. Anderson, K.M. Bischoff, T.R. Callaway, and L.F. Kubena. 2001. Effect of lactic acid administration in the drinking water during preslaughter feed withdrawal on Salmonella and Campylobacter contamination in broilers. Poult. Sci. 80:278-283.

Christianson, Laura E. and Helmers, Matthew J. 2011. “Woodchip Bioreactors for Nitrate in Agricultural Drainage”. Agriculture and Environmental Extension Publication Book 85.

http://www1.agric.gov.ab.ca/$department/deptdocs.nsf/all/agdex621#table6

http://manitoba.ca/waterstewardship/reports/groundwater/hg_of_manitoba.pdf




http://lib.dr.iastate.edu/extension_ag_pubs/85. Iowa State University.

Christianson, Laura E., Bhandari, A., Helmers, M.J. 2012. “A Practice-Oriented Review of Woodchip Bioreactors for Subsurface Agricultural Drainage”. Applied Engineering in Agriculture. ASABE. Vol.28(6): 861-874.

Christianson L., Helmers, M.J., Tyndall, J., “Financial Comparison of Seven Nitrate Reduction Strategies for Midwestern Agricultural Drainage”. Water Resources and Economics (2013), http://dx. doi.org/10.1016/j.wre.2013.09.001.

B. Ball Coelho, D. Lapen, R. Murray, E. Topp, A. Bruin, B. Khand. 2012. Nitrogen loading to offsite waters from liquid swine manure application under different drainage and tillage practices. Agric. Water Man. 104:40-50.

B. Ball Coelho, R. Murray, D. Lapen, E. Topp, A. Bruin. 2012. Phosphorus and sediment loading to surface waters from liquid swine manure application under different drainage and tillage practices. Agric. Water Man. 104:51-61.

Comerford N.B. 2005. Soil factors affecting nutrient bioavailability. In H. BassiriRad (ed). Nutrient Acquisition by Plants – An Ecological Perspective. Springer-Verlag, Berlin.

Cooley, E.T., Ruark, M.D., and Panuska, J.C. 2013. “Managing Tile-Drained Landscape to Prevent Nutrient Losses”, University of Wisconsin Discovery Farms, Fact Sheet No. 3 GWQ064- Madison, Wisconsin.

Cordeiro, M.R.C., 2013. “Agronomic and Environmental Impacts of Corn Production under Different Water Management Strategies in the Canadian Prairies”. PhD Thesis. Department of Bio Systems Engineering. University of Manitoba. Winnipeg, Manitoba.

Crumpton, W.G., Stenback, G.A., Miller, M.A., Helmers, M. J. 2006. “Potential Benefits of Wetland Filters for Tile Drainage Systems: Impact on Nitrate Loads to Mississippi River Subbasins”, Final Project Report to U.S. (Proj. No. IOW06682), Department of Agriculture, 2006 ⟨http://www.fsa.usda.gov/Internet/FSA_File/fsa_final_report_crumpton_rhd.pdf⟩.

Crumpton, W.G., Helmers, M.J., Stenback, G.A., Lemke, D.W. and Richmond, S. 2012. “Integrated Drainage Wetland Systems for Reducing Nitrate Loads from Des Moines Lobe Watersheds". (2012). Agricultural and Biosystems Engineering Technical Reports and White Papers. Paper 13. http://lib.dr.iastate.edu/abe_eng_reports/13.

Dils R.M. and A.L. Heathwaite. 1999. The Controversial Role of Tile Drainage in Phosphorous Export from Agricultural Land. Water Sci & Tech 39(12):55-61.

Dolezal, F., Z. Kulhavy, M. Soukup, and R. Kodesova. 2001. Hydrology of tile drainage runoff. Phys. Chem. Earth B 26:623–627.

http://lib.dr.iastate.edu/extension_ag_pubs/85

http://lib.dr.iastate.edu/abe_eng_reports/13

https://www.researchgate.net/profile/Ann_Heathwaite2




Drury, C.F., C.S. Tan, T.W. Welacky, W.D. Reynolds, T.Q. Zhang, T.O. Oloya, N.B. McLaughlin, and J.D. Gaynor. 2014. "Reducing nitrate loss in tile drainage water with cover crops and water-table management systems." Journal of Environmental Quality, 43(2), pp. 587-598.

Ebner, P.D. and A.G. Mathew. 2000. Effects of antibiotic regimens on the fecal shedding patterns of pigs infected with Salmonella Typhimurium. J. Food Protect. 63:709-714.

FCC. 2014. “Farmland Values Report, 2014”. Government of Canada Publication. https://www.fcc-fac.ca/fcc/about-fcc/corporate-profile/reports/farmland-values/farmland-values-report-2014-pdf.

Fertilizer Canada. No date. Nutrient Stewardship – 4R Nutrient Stewardship Planning Guide for Manitoba. Available at https://cdn2.fertilizercanada.ca/wp-content/uploads/2015/07/4R-Nutrient-Stewardship-Planning-Guide-for-Manitoba-English.pdf (accessed September 13, 2016).

Feyereisen, G.W., Francesconi, W., Smith, D.R., Papiernik, S.K., Kruger, E.S., Wente, C.D. 2015. “Effect of Replacing Surface Inlets with Blind or Gravel Inlets on Sediment and Phosphorus Subsurface Drainage Losses”. Journal of Environmental Quality. 2015 Mar; 44(2):594-604- Doi:10.2134/jeq2014-05.0219.

Fleming, R. J., Bradshaw, S.H., 1992. “Detection of Soil Macropores Using Smoke”. Canadian Society for Agricultural Engineering. Agricultural Institute of Canada Annual Meetings. Brandon, Manitoba, July 5-9. Paper 92-103.

Freeze, R. A., and Witherspoon, P.A. 1967. "Theoretical Analysis of Regional Groundwater Flow: 2. Effect of Water‐table Configuration and Subsurface Permeability Variation." Water Resources Research 3.2: 623-634.

Freeze, R. Al., and Witherspoon, P.A. 1966. "Theoretical Analysis of Regional Groundwater Flow: 1. Analytical and Numerical Solutions to the Mathematical Model." Water Resources Research 2.4: 641-656.

Frey S.K., D.L. Rudolph, D.R. Lapen, B.R. Ball Coelho. 2012. Viscosity dependent dual-permeability modeling of liquid manure movement in layered, macroporous, tile drained soil. Water Resour. Res. 48, W00L11, doi:10.1029/2011WR010809.

Frey S.K., E. Topp, B. R. Ball, M. Edwards, N. Gottschall, M. Sunohara, E. Zoski, and D.R. Lapen. 2013. Tile Drainage Management Influences on Surface-Water and Groundwater Quality following Liquid Manure Application. J. Environ. Qual. 42:881–892 (2013), doi:10.2134/jeq2012.0261.

Gaia Consulting Limited. 2007. 2006 Manitoba Irrigation Survey.

Gburek W.J., E. Barbers, P.M. Haygarth, B. Kronvang, C. Stamm. 2005. Phosphorus mobility in the landscape. In: Sims J.T. and Sharpley A.N. (editors). 2005. Phosphorus: Agriculture and the

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/drury-craig-phd/?id=1181935966389

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/tan-chin-phd/?id=1181922955360

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/welacky-tom-msc/?id=1181925535876

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/reynolds-dan-phd/?id=1181920244629

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/zhang-tiequan-phd/?id=1181926163334

http://www.agr.gc.ca/eng/?id=1181851140502

https://www.fcc-fac.ca/fcc/about-fcc/corporate-profile/reports/farmland-values/farmland-values-report-2014.pdf

https://www.fcc-fac.ca/fcc/about-fcc/corporate-profile/reports/farmland-values/farmland-values-report-2014.pdf

https://cdn2.fertilizercanada.ca/wp-content/uploads/2015/07/4R-Nutrient-Stewardship-Planning-Guide-for-Manitoba-English.pdf

https://cdn2.fertilizercanada.ca/wp-content/uploads/2015/07/4R-Nutrient-Stewardship-Planning-Guide-for-Manitoba-English.pdf




environment. American Society of Agronomy Inc., Crop Science Society of America Inc., Soil Science Society of America Inc. Madison, Wisconsin.

Gessel, P.D., N.C. Hansen, S.M. Goyal, L.J. Johnston, and J. Webb. 2004- Persistence of zoonotic pathogens in surface soil treated with different rates of liquid pig manure. Appl. Soil. Ecol. 25:237-243.

Grimes, D.W. and D.W. Henderson. 1984. “Developing the Resource Potential of a Shallow Water Table”. Project # B-216-CAL. Davis: California Water Resources Center, University of California.

Grismer, Mark. 2015. University of California. “Use of Shallow Groundwater for Crop Production”, Agriculture and Natural Resources Publication 8521; https://anrcatalog.ucanr.edu/pdf/8521.pdf.

Grismer, M.E. and T.K. Gates. 1988. “Estimating Saline Water Table Contributions to Crop Water Use”. California Agriculture 32(2): 23-24.

Guan, T.Y. and R.A. Holley. 2003. Pathogen survival in swine manure environments and transmission of human enteric illness—a review. J. Environ. Qual. 32:383-392.

Hao X. and M. Benke. 2012. Long-Term Cattle Manure Plots. Prairie Soils and Crops Journal 5:132-138.

Hao, X.J., Zhang, T.Q., Tan, C.S., Welacky, T.W., Wang, Y.T., Lawrey, J.D., and Hong, J.P. 2015. "Crop Yield and Phosphorus Uptake as Affected by Phosphorus-Based Swine Manure Application under Long-Term Corn-Soybean Rotation." Nutrient Cycling in Agroecosystems, 103(2), pp. 217-228. doi : 10.1007/s10705-015-9735-0.

Harland, M., Shewfelt, P.B., Yarotski, J., Oosterveen, J., Miller, T., Braul, L. 1997. “Tile Drainage in Manitoba”. USCID Conference on Best Management Practices for Irrigated Agriculture and the Environment. Fargo, ND, July 16-19.

Harrigan, T., and Northcott, B. 2007. “Keeping Land Applied Manure in the Root Zone; Part 2 – Tile Drained Land”. Michigan State Extension Bulletin WO-1037. February.

Harrigan, T.,Strock, J., Kleiman, P., Hoorman, J., and Brown, L. 2015. “Nutrient and Manure Management on Tile Drained Land”. Extension seminar. Livestock and Poultry Environmental Learning Center. http://articles.extension.org/sites/default/files/15aprflyer.pdf.

Harris, B. (2015, September 9). RM addresses manure on tile-drained land. PortageOnline. Retrieved from http://www.portageonline.com/local/45297-rm-addresses-manure-on-tile-drained-land# (accessed March 2, 2016).

Havlin J.L., J.D. Beaton, S.L. Tisdale, W.L. Nelson. 2005. Soil fertility and fertilizers - An introduction to nutrient management. Upper Saddle River, New Jersey.

https://anrcatalog.ucanr.edu/pdf/8521.pdf

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/zhang-tiequan-phd/?id=1181926163334

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/tan-chin-phd/?id=1181922955360

http://www.agr.gc.ca/eng/science-and-innovation/research-centres/ontario/harrow-research-and-development-centre/scientific-staff-and-expertise/welacky-tom-msc/?id=1181925535876

http://articles.extension.org/sites/default/files/15aprflyer.pdf

http://www.portageonline.com/local/45297-rm-addresses-manure-on-tile-drained-land

http://www.portageonline.com/local/45297-rm-addresses-manure-on-tile-drained-land




Hedley M., M. McLaughlin. 2005. Reactions of phosphate fertilizers and by-products in soils. In: Sims J.T. and Sharpley A.N. (editors). 2005. Phosphorus: Agriculture and the environment. American Society of Agronomy Inc., Crop Science Society of America Inc., Soil Science Society of America Inc. Madison, Wisconsin.Hernandez-Ramirez, G., Brouder, S.M., Ruark, M.D., & Turco, R.F. 2011. “Nitrate, Phosphate, and Ammonium Loads at Subsurface Drains; Agroecosystems and Nitrogen Management”. Journal of Environmental Quality, 40, 1229-1240.

Hernandez J.A. and Schmitt M.A. 2012 Manure Management in Minnesota. University of Minnesota Extension publication WW.03553.

Hill, A.R. 1976. The environmental impacts of agricultural land drainage. Journal of Environmental Management. 4:251-274.

Hoorman, J. J., Rausch, J,. N., Harrigan, T.M., Bickert, W.G., Shipitalo, M.J., Reamer, J.R., Gibbs, F.E., Gangwar, J.J. and Brown, L.C. 2005. “Summary of Educationand Research Priorites for Liquid Manure Application to Drained Cropland; Preferential Flow Issues and Concerns”. ASABE Meeting, Paper No. 52062. Tampa Bay, FL.

Hoorman, J.J. & Shipitalo, M.J. 2006. Subsurface Drainage and Liquid Manure. Journal of Soil and Water Conservation, 61(3), 94A-97A.

Hoorman, J. J., Rausch, J. N., Brown, L.C., 2009. “Guidelines for Applying Liquid Animal Manure to Cropland with Subsurface and Surface Drains”. Ohio State University Extension Publication ANR21. Last Updated 10/29/2009. http://ohioline.osu.edu/factsheet/ANR-21.

Hutchison, M.L, L.D. Walters, A. Moore, K.M. Crookes, and S.M. Avery. 2004- Effect of length of time before incorporation on survival of pathogenic bacteria present in livestock wastes applied to agricultural soil. Appl. Environ. Microbiol. 70:5111-5118.

Iovanna R., Hyberg S., Crumpton W., Treatment wetlands: cost-effective practice for intercepting nitrate before it reaches and adversely impacts surface waters, Journal of Soil and Water Conservation 63 (2008) 14A–15A.

Jensen, M.B., P.R. Jorgensen, H.C.B. Hansen, and N.E. Nielsen. 1998. Biopore mediated subsurface transport of dissolved orthophosphate. J. Environ. Qual. 27:1130–1137.

Kalita, P.K., Cooke, R., Anderson, S.M., Hirschi, M.C., Mitchell, J.K. 2007. “Subsurface Drainage and Water Quality: The Illinois Experience”. Transactions of the ASABE. Vo. 50(5): 1651-1656.

King, K.W., Williams, M.R., Macrae, M. L., Fausey, N.R., Frankenberger, J., Smith, D.R., Kleinman, Brown, L.C. 2015. “Phosphorus Transport in Agricultural Subsurface Drainage: A Review”. Journal of Environmental Quality. March, 2015. Doi: 10.2134/jeq2014-04-0163.

Kleinman, Peter J., Smith, D. R., Bolster, C. H., Easton, Z.M. 2015. Phosphorus Fate, Management, and Modelling in Artificially Drained Systems. Journal of Environmental Quality. Vol. 44 No. 2.

http://ohioline.osu.edu/factsheet/ANR-21




http://dx.doi.org/10.2134/jeq2015.02.0090.

Lawrence J., Q. Ketterings, K. Czymmek, S. Mahoney, E. Young, L. Geohring. 2011. Subsurface (Tile) Drainage - Best Management Practices. Agronomy Fact Sheet Series. Fact Sheet 58. Cornell University Cooperative Extension.

Leopold Center. 2013. Success Stories in Sustainable Agriculture. Saturated Buffers.

Lory A. and R. Massey. 2006. Using Manure as a Fertilizer for Crop Production. Available at https://www.epa.gov/sites/production/files/2015-07/documents/2006_8_25_msbasin_symposia_ia_session8.pdf (accessed September 13, 2016).

Manitoba Soil Fertility Advisory Committee. 2007. Manitoba soil fertility guide.

MAFRI (Manitoba Agriculture, Food and Rural Initiatives). 2008. Soil management guide.

Mahoney S., J. Lawrence, Q. Ketterings, K. Czymmek, E. Young, L. Geohring. 2011. Subsurface (Tile) Drainage - Benefits and Installation Guidance. Agronomy Fact Sheet Series. Fact Sheet 57. Cornell University Cooperative Extension.

McGarry, P., Pries, J. 2001. Constructed Wetlands For Feedlot Runoff Treatment in Manitoba. http://agrienvarchive.ca/bioenergy/download/WEAO_2001_Pries.pdf.

Michalyna, W. and Podolsky, G., and St. Jacques, E., 1988. Soils of the Rural Municipalities of Grey, Dufferin, Roland, Thompson and part of Stanley, Canada - Manitoba Soil Survey Report D60, 1988. Published by Manitoba Department of Agriculture. MOVE

Miller, T.P., J.R. Peterson, C.F. Lenhart, and Y. Nomura. 2012. The Agricultural BMP Handbook for Minnesota. Minnesota Department of Agriculture.

Mitsch, W.J. and D.L. Fink. 2001. Wetlands for controlling nonpoint source pollution from agriculture: Indian Lake wetland demonstration project, Logan County, OH.

Muralidhara, K.S., G.G. Sheggeby, P.R. Elliker, D.C. England, and W.E. Sandine. 1977. Effect of feeding Lactobacilli on the coli-form and Lactobacillus flora of intestinal tissue and feces from pigs. J. Food Prot. 40:288-295.

Ohya, T., T. Marubashi, and H. Ito. 2000. Significance of fecal volatile fatty acids in shedding of Escherichia coli O157 from calves: experimental infection and preliminary use of a probiotic product. J. Vet. Med. Sci. 62: 1151 -1155.

Ontario Government. Drainage Guide for Ontario. Publication 29. http://www.omafra.gov.on.ca/english/landuse/facts/drain_p29.htm.

http://dx.doi.org/10.2134/jeq2015.02.0090

https://www.epa.gov/sites/production/files/2015-07/documents/2006_8_25_msbasin_symposia_ia_session8.pdf

https://www.epa.gov/sites/production/files/2015-07/documents/2006_8_25_msbasin_symposia_ia_session8.pdf

http://www.omafra.gov.on.ca/english/landuse/facts/drain_p29.htm




Nisbet, D.J., R.C. Anderson, R.B. Harvey, K.J. Genovese, J.R. DeLoach, and L.H. Stanker. 1999. Competitive exclusion of Salmonella serovar Typhimurium from the gut of early weaned pigs. Pages 80-82 in Proc. 3rd Int. Symp. on the Epidemiology and Control of Salmonella in Pork. Washington, D.C.

Peterson, 2009; Conservation Practices for Agriculture. 2009 Minnesota Association of Watershed Districts Meeting. http://www.bwsr.state.mn.us/drainage/cons_drainage_MAWD_2009.pdf.

Prairie Province’s Committee on Livestock Development and Manure Management. 2004. Manure Application and Use Guidelines, Manitoba Version.

Randall, G.W. 2003. Nutrient and pathogen losses to subsurface tile drainage from swine manure. A research report prepared for the National Pork Board. NPB #02-095. Available online at http://old.pork.org/filelibrary/researchdocuments/02-095-randall.5-28-03.pdf (accessed March 2, 2016).

Racz, G. 1981. Phosphorus application for annual crops. Manitoba Agriculture Farm Facts. Agdex 541.

Radcliffe, D.E, D.K. Reid, K. Blombäck, C.H. Bolster, A.S. Collick, Z.M. Easton, W. Francesconi, D.R. Fuka, H. Johnsson, K. King, M. Larsbo, M.A. Youssef, A.S. Mulkey, N.O. Nelson, K. Persson, J.J. Ramirez-Avila, F. Schmieder, and D.R. Smith. 2015. Applicability of Models to Predict Phosphorus Losses in Drained Fields; A Review. Journal of Environmental Quality. 44:614–628. doi:10.2134/jeq2014-05.0220.

Randall, G.W., and Mulla, D.J. 2011. “Nitrate Nitrogen in Surface Waters as Influenced by Climatic Conditions and Agricultural Practices“. Journal of Environmental Quality 20:337-344.

Randall, G.W., and Sawyer, J. E., 2008. Nitrogen Timing, Forms and Additives. Final Report: Gulf Hypoxia and Local Water Quality Concerns Workshop. St. Joseph, Michigan: ASABE. Pp. 73-85 in UMRSHNC (Upper Mississippi River Sub-Basin Hypoxia Nutrient Committee).

Rutulis, M. 1985. Springs in Southern Manitoba. Manitoba Water Resources Branch.

Sands, Gary, and Busman, Lowell. 2009. Issues and Answers. Agricultural Drainage Publication Series. University of Minnesota, 2009. Web http://www.extension.umn.edu/distribution/ cropsystems/DC7740.html.

Sands, Gary, and Wright, Jerry. Planning an Agricultural Sub Surface Drainage System. Agricultural Drainage Publication Series. University of Minnesota, 2001. Web http://www.extension.umn.edu/ agriculture/water/publications/pdfs/planning_for_a_drain_system.pdf.

Sands, 2013. Developing Optimum Drainage Design Guidelines for the Red River Basin; Department of Bioproducts and Biosystems Engineering, University of Minnesota, January, 2013.

http://www.bwsr.state.mn.us/drainage/cons_drainage_MAWD_2009.pdf

http://www.extension.umn.edu/distribution/%20cropsystems/DC7740.html

http://www.extension.umn.edu/distribution/%20cropsystems/DC7740.html

http://www.extension.umn.edu/%20agriculture/water/publications/pdfs/planning_for_a_drain_system.pdf

http://www.extension.umn.edu/%20agriculture/water/publications/pdfs/planning_for_a_drain_system.pdf




Web http://www.extension.umn.edu/agriculture/water/reports/docs/ final_report__developing_drainage_guidelines_for_rrb_sands.pdf.

Satchithanantham, Sanjayan; R. Sri Ranjan, R. Sri., Shewfelt, B. 2012. Effect of Water Table management and Irrigation on Potato Yields; Transactions of the Association of Agricultural and Biological Engineers; 55(6): 2175-2184; October, 2012.

Simard, R.R., S. Beauchemin, and P.M. Haygarth. 2000. Potential for preferential pathways of phosphorus transport. J. Environ. Qual. 29:97–105.

Sims J.T. and Sharpley A.N. (editors). 2005. Phosphorus: Agriculture and the environment. American Society of Agronomy Inc., Crop Science Society of America Inc., Soil Science Society of America Inc. Madison, Wisconsin.

Skaggs, R.W., Youssef, M.A., Chescheir, G.M. 2012. DRAINMOD: Model Use, Calibration, and Validation. Transactions of the American Society of Agricultural and Biological Engineers; Vol. 55(4): 1509-1522.

Smith, D.R. and Livingston, S.J. 2013. Managing Farmed Closed Depressional Areas Using Blind Inlets to Minimize Phosphorus and Nitrogen Losses. Soil Use and Management, March 2013, 29 (Suppl. 1), 94-102.

Smith, D.R., King, K.W., Johnson, L., Francesconi, W., Richards, P., Baker, D., Sharpley, A.N. 2015. Surface Runoff and Tile Drainage Transport of Phosphorus in the Midwestern United States. 2015 Mar; 44(2); 495-502. Doi:10.2134/jeq2014-04-0176.

Sobsey, M.D., L.A. Khatib, V.R. Hill, E. Alocilja, S. Pillai. 2006. Pathogens in animal wastes and the impacts of waste management practices on their survival, transport and fate. In Animal Agriculture and the Environment: National Center for Manure and Animal Waste Management White Papers. J.M. Rice, D.F. Caldwell, F.J. Humenik, eds. 2006. St Joseph, Michigan: ASABE. Pub. Number 913C0306.

Spiehs M. and S. Goyal. 2007. Best management practices for pathogen control in manure management systems. University of Minnesota Extension. Available at: http://www.extension.umn.edu/agriculture/manure-management-and-air-quality/manure-pathogens/best-management-practices/docs/pathogen-control.pdf (accessed April 8, 2016).

Stamm, C., H. Fluhler, R. Gachter, J. Leuenberger, and H. Wunderli. 1998. Preferential transport of phosphorus in drained grassland soils. J. Environ. Qual. 27:515–522.

Stantec. 2013. Scope and Method for Determining the Water Footprint of Agricultural Crop Production at the Field Level (draft). Prepared for Agriculture and Agri-Food Canada’s Science and Technology Branch.

http://www.extension.umn.edu/agriculture/water/reports/docs/%20final_report__developing_drainage_guidelines_for_rrb_sands.pdf

http://www.extension.umn.edu/agriculture/water/reports/docs/%20final_report__developing_drainage_guidelines_for_rrb_sands.pdf

http://www.extension.umn.edu/agriculture/manure-management-and-air-quality/manure-pathogens/best-management-practices/docs/pathogen-control.pdf

http://www.extension.umn.edu/agriculture/manure-management-and-air-quality/manure-pathogens/best-management-practices/docs/pathogen-control.pdf




State Line Observer, 2005. Down the Drain, Liquefied Manure and Tile. News Article Access June 14, 16. http://statelineobserver.com/stories/local-stories/252-down-the-drain-liquefied-manure-and-drainage-tile.

Sukais, J. and Tanner, C. 2011. Surface Flow Constructed Wetlands as a Drainage Management Tool – Long Term Performance. http://www.massey.ac.nz/~flrc/workshops/11/Manuscripts/Sukias_2011.pdf.

Tan, C.S., Zhang, T.Q., Drury, C.F., Reynolds, W.D., Oloya, T. and Gaynor, J.D. 2007. Water Quality and Crop Production Improvement Using a Wetland-Reservoir and Drainage/Subsurface Irrigation System. Canadian Journal of Water Resources. Vol 32(2) 129-136 (2007).

Tan, C.S., Zhang, T.Q., Zheng, Z.M., 2015. Impact of Subsurface Drainage Management and Organic Manure and Chemical Fertilizer on Nutrient Loss. ASABE Annual International Meeting. New Orleans, LA, July 28-29. 818-840.

Tanner, C.C.; Sukias, J.P.S.; Yates, C.R. (2010). New Zealand Guidelines: Constructed Wetland Treatment of Tile Drainage. NIWA Information Series No. 75 National Institute of Water & Atmospheric Research Ltd. https://www.niwa.co.nz/sites/niwa.co.nz/files/import/attachments/NZCW-guide4press_small.pdf.

Toth, Jozsef. 1963. A Theoretical Analysis of Groundwater Flow in Small Drainage Basins. Journal of Geophysical Research 68.16: 4795-481.

Toth, Jozsef. 1999. Groundwater as a Geologic Agent: an Overview of the Causes, Processes, and Manifestations. Hydrogeology Journal 7.1: 1-14.

Ulen B. Episodic precipitation and discharge events and their influence on losses of phosphorus and nitrogen from tile-drained arable fields. Swedish J. Agric. Res. 25:25-31.

University of Guelph. 2001. Fraser, Heather and Fleming, Ron. Environmental Benefits of Tile Drainage – Literature Review. Prepared for Land Improvement Contractors of Ontario.

USDA-NRCS; Conservation Practice Standard. Nutrient Management. Code 590. August, 2006.

USDA-NRCS; Conservation Practice Standard. Wetland Restoration. Code 657, September, 2010.

USDA-NRCS; Conservation Practice Standard. Wetland Creation. Code 658, September, 2010.

USDA-NRCS; Conservation Practice Standard. Wetland Enhancement. Code 659, September, 2010.

USDA-NRCS: Program Sheet CRP CP39. Constructed Wetland. NRCS Michigan March, 2011.

USDA-NRCS; Conservation Practice Standard. Vegetated Subsurface Drain Outlet. Cod 739, July,

http://statelineobserver.com/stories/local-stories/252-down-the-drain-liquefied-manure-and-drainage-tile

http://statelineobserver.com/stories/local-stories/252-down-the-drain-liquefied-manure-and-drainage-tile

http://www.massey.ac.nz/%7Eflrc/workshops/11/Manuscripts/Sukias_2011.pdf

https://www.niwa.co.nz/sites/niwa.co.nz/files/import/attachments/NZCW-guide4press_small.pdf




2012.

USDA-NRCS; Conservation Practice Standard. Underground Outlet. Code 620, February 2015.

USDA-NRCS; Conservation Practice Standard. Tile Intake Replacement. Interim Code IA-980.

USDA-NRCS: Conservation Practice Standard. Binitrifying Bioreactor. Code 747. n.d.

van der Wolf, P.J., F.W. van Schie, A.R.W. Elbers, B. Engel, H.M.J.F. van der Heijden, W.A. Hunneman, and M.J.M. Tielen. 2001. Administration of acidified drinking water to finishing pigs in order to prevent Salmonella infections. Vet. Quart. 23:121-125.

Vermont Agency of Agriculture, Food and Markets [VAAFM] and Vermont Agency of Natural Resources [VANR]. 2016. Vermont’s subsurface tile drainage interim report. Available online at http://agriculture.vermont.gov/sites/ag/files/pdf/water_quality/Tile-Drain/VAAFM-VANR-Subsurface-Tile-Drainage-Interim-Report-02152016.pdf (accessed March 2, 2016).

Woltemade, C.J. 2000. Ability of Restored Wetlands to Reduce Nitrogen and Phosphorus Concentrations in Agricultural Drainage Water. Journal of Soil and Water Conservation. vol. 55 no. 3.

Zhao, T., M.P. Doyle, B.G. Harmon, C.A. Brown, P.O. Mueller, and A.H. Parks. 1998. Reduction of carriage of enterohemorrhagic Escherichia coli O157:H7 in cattle by inoculation with probiotic bacteria. J. Clin. Microbiol. 36:641–647.

http://agriculture.vermont.gov/sites/ag/files/pdf/water_quality/Tile-Drain/VAAFM-VANR-Subsurface-Tile-Drainage-Interim-Report-02152016.pdf

http://agriculture.vermont.gov/sites/ag/files/pdf/water_quality/Tile-Drain/VAAFM-VANR-Subsurface-Tile-Drainage-Interim-Report-02152016.pdf

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