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SOIL AND WATER MANAGEMENT
Soil Functions
Nutrient Cycling
Carbon Cycling
Soil
WaterCycling
Plant Growth
Chemical Fate &
Transport
BiodiversityProtection
CONSEQUENCES OF MISMANAGEMENT
CRITICAL SOIL PROPERTIES AND
FUNCTIONS
Gas
Liquids
Solids
Pores
Porosity – Proportion of Pores
Volume of Pores
Total Soil Volume
= Porosity
Soil texture and particle size
Infiltration
■ How quickly water enters the soil
■ Impacted by:
- Soil Texture
- Pore size
Macropores
Alaou and Goetz, Geoderma 2008Sophocleuos et al., Kansas State Geological survey
Soil structure and macroporesimpact infiltration
Slope and Infiltration
Rain
Infiltration
RainInfiltration
Low Slope Field High Slope Field
Factors Influencing Infiltration■ Soil Texture
Sandy ClayeyHigh infiltration Low Infiltration
■ Porosity (greater porosity = more infiltration)
– Porosity is influenced by compaction
■ Slope (Higher Slope = less infiltration)
Importance of Porosity
Porosity controls:• Maximum water
content of soils• Root Aeration• Water infiltration
Compaction: • Decreases Porosity• Increases Density
Compaction degrades pore networks
Source: The Nature and Properties of Soil, 15e, Ray R. Weil and Nyle C. Brady
Source: The Nature and Properties of Soil, 15e, Ray R. Weil and Nyle C. Brady
Source: The Nature and Properties of Soil, 15e, Ray R. Weil and Nyle C. Brady
Source: The Nature and Properties of Soil, 15e, Ray R. Weil and Nyle C. Brady
• Tillage can influence Compaction susceptibility
• Effects are greatest in young soils (e.g. soils in the Midwest)
Young Prairie Soil (Nebraska)
Very Old Forest Soil (Kentucky)
Factors influencing compaction■ Moist soil is weaker and more susceptible to compaction
(avoid traffic on wet soils)
■ High OM soils are less susceptible
■ High tillage increases compaction susceptibility
■ Heavy vehicle traffic increases compaction
– High volume tires (and tracks) keep compaction shallow
WATER QUALITY
Ag. Chemical
Volatilization /off-gassing
Deposition
Leaching
Flow in deep ground water
Surface Water
Groundwater
Importance of each mechanism depends on:• Chemical Type• Application Timing• Application method• Landscape (soil, slope, infiltration, conservation
practice, etc.)
Right Source
Right Rate
Right Time
Right Place
4 R’s of Nutrient Management
Right Rate
Manure/fertilizer application timing (Right Time)
SOIL EROSION
Mechanism of soil erosion
Erosion vs. Sedimentation
Erosion = movement of soil (via wind or water)
Sedimentation = impairment of water bodies by excess sediment additions
CONSERVATION PRACTICES
Riparian buffers and filter strips
Contours and grass waterways
Contour strips and buffers
Grass waterways
Cover Crops
Cover crops
Conventional vs. reduced/conservation tillage
Conservation Tillage = more crop residue