The Vermont Dairy Farm Sustainability Project, Inc.pss.uvm.edu/vtcrops/vdfsp/VDFSP_WebPpt_0606.pdf2006-06-16The Vermont Dairy Farm Sustainability Project, Inc. The Vermont Dairy Farm Sustainability Project ... Use of Phosphorous Index to reduce risk of phosphorous

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  • The Vermont Dairy Farm Sustainability

    Project, Inc.

  • The Vermont Dairy Farm Sustainability Project

    A Collaboration to Improve Dairy Farm Nutrient Balance

    Greg Weber, Project Coordinator, 2001-2003 Bill Jokela, Univ. of Vermont, Interim Coordinator, 2003-2005Slide show created by Greg Weber; revised by Bill JokelaPhoto credits: Bill Jokela

  • A Collaboration Involving:Ben & JerrysSt. Albans Coop.Poulin GrainBourdeau Bros. of Middlebury

    University of Vermont Extension8 Dairy Farmers

    Funding from: Ben & Jerrys, NE SARE, The Ben & Jerrys and Windham Foundations.

  • Issues in Dairy Farm Sustainability

    EnvironmentalWater quality impacts

    Surface water P in runoff, erosionGroundwater nitrate leaching

    EconomicFarm profitability

    Milk priceProduction levelCost of production

  • Ben & Jerrys initiated an industry collaboration to investigate and document management practices that improve farm environmental and economic sustainability.

    Response

  • Unique Aspects of VDFSPWhole-farm nutrient approach

    Cows and feedCrops and soil

    CollaborativePrivate industry/public (university, Extension)Ag suppliers, consultants, processorsFarmers

    Environmental and Economic Goals

  • Technical Goals of VDFSP

    More precisely match feed supply to cow requirements.

    Utilize CNCPS software to reduce overfeeding of N and P.More precisely match manure and fertilizer application to crop requirements.

    Use of CropMD software to match application to requirements.Use of Phosphorous Index to reduce risk of phosphorous run-off.

    More precisely match crops grown on farm to herd nutritional requirements and soil fertility.

  • Approach

    BaselineOne year period to document N and P status of whole farm, feed and crop enterprises on 8 farms

    Nutrient Management Improvement PlanOpportunity identification, improvement plan development and implementation in collaboration with farmer, farm suppliers and advisors

    ImplementationOne year period to document impact of improvement implementations

    Educational PhaseDissemination of information to dairy industry concerning successful improvements for N and P efficiency and lessons learned

  • Feed Enterprise

    Periodic evaluation of diet N and P supply relative to requirement, by group(Use Cornell Net Carbohydrate and Protein System v4.0.31

    (CNCPS) software)

    Measured intake.Production level.Physiologic state.

    Work with feed suppliers, dairy nutritionists

  • Crop EnterpriseEvaluation of N and P supply relative to crop requirement, by field( Use VT CropMD or proprietary (NNYCMA) software.)

    Soil sampling and testingManure analysis and managementFertilizer applicationExpected crop yield/crop managementEvaluate P runoff potential with P Index

    Work with fertilizer suppliers and crop consultants.

  • Project success depended on farmer-cooperators, agsuppliers/consultants, and project staff working together for a common goal. Here project coordinator Greg Weber discusses management issues with a farmer and his crop consultant.

  • Whole FarmImports

    Feed, Animals, Fertilizer, N Fixation.Exports

    Milk, Feed, Manure, AnimalsWhole-farm nutrient balance

    Refers to the proportion of imported nutrients that are converted to useable product or retained on the farmMore nutrient retained means increased potential for loss to the environment via runoff or leaching

  • Feed

    Fertilizer

    Fixed N

    Milk andAnimalsConversion Efficiency

    Accumulation

    Farm Boundary

    Farm Boundary

  • Where are the Opportunities?

    Look at Results for Baseline Year8 Dairy Farms

    80-300 milkers (1 heifer operation)Cropland: 130-900 acres

    Most legume-grass and corn silageOne pasture-based

    7 in VT, 1 in NY

  • Conversion Efficiency

    Conversion Efficiency

    Nutrient Allocation, Timing, Method, Crops Grown

    Diet ParametersCP, MP, NSC, Rumen N, P

    Crops

    Feed

    Nutrient Accumulation

    ManureNutrients

    Total CropNutrients

    Crop NutrientSupply

    Home GrownRation Nutrients

    Total IntakeRation Nutrients

    NFixation

    PurchasedFertilizer

    PurchasedFeed

    Nutrient ExportIn Milk + Animals

    Farm Boundary

    Farm Boundary

    SoilNutrients

  • Whole Farm Nutrient Conversion EfficiencyExported N or P, as percent of imported nutrient

    Feed Nutrient Conversion EfficiencyProduct (milk and tissue) as percent of intake.

    Crop Nutrient StatusApplied crop available nutrient amount minus recommended application rate.

    Results

  • Whole-farm Phosphorus ImportBaseline Year

    Phosphorus Imports

    0

    2

    4

    6

    8

    10

    12

    14

    16

    1 2 3 4 5 6 7 8

    Farm

    Tons

    BeddingLivestock

    FertillizerPurchased Feed

    On most farms purchased feed was the largest import of P; fertilizer was the largest on others

  • Whole-farm Phosphorus ExportBaseline Year

    Phosphorus Exports

    0

    1

    2

    3

    4

    5

    6

    1 2 3 4 5 6 7 8

    Farm

    Tons

    Manure

    Forages

    Livestock

    Milk

    Milk was the primary P export (except on heifer operation)

  • Whole-farm P BalanceBaseline Year

    Phosphorus Mass Balance

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    1 2 3 4 5 6 7 8

    Farm

    Perc

    ent

    % Retained% Converted

    Conversion efficiencies ranged from 20 to 50% (50 to 80% retained), except for a grazing-based farm with a large land base, which had a 75% conversion efficiency.

  • Whole-farm Nitrogen BalanceBaseline Year

    Nitrogen Mass Balance

    0

    10

    20

    30

    40

    50

    60

    70

    80

    90

    100

    1 2 3 4 5 6 7 8

    Farm

    Tons

    % Retained% Converted

  • How much N and P in feed?

  • Farm 1 2 3 4 5 6 8 Average

    Dietary Crude Protein % 17.7 17.3 18.4 17.4 17.2 18.3 18.3 17.8

    Ruminal N Supply (% of req.) 129.5 121.4 143.0 144.8 126.4 150.4 129.7 135.0

    MP N Supply (% of req.) 107.1 106.7 105.2 92.5 103.4 103.3 112.7 104.4

    P Intake (% of req.) 111.0 111.6 124.0 127.3 116.4 99.7 120.5 115.8

    Lactating Averages - Baseline Year

    Feed Characteristics

    Overfeeding of N and P lowers nutrient efficiency and increases manure nutrient content.

  • Manure Application

    Farm 1 2 3 4 5 7 8Manure Rate, gal/Acre 6956 7526 5122 6968 5188 ? 3646% Acres Manured 63 94 81 94 83 77 62

    Manure sampled and analyzed 1-3 x per farm

    Percent of Acreage Manured by CropCorn silage 82%Legume-grass 68%Grass 76%

  • can result in phosphorus in runoff.

    Phosphorus in manure

  • Fertilizer Use: Phosphorus

    Commercial Fertilizer P Application

    Crop Acres Total Per AcreCorn Silage 1289 78138 61Legume-Grass Forage 2131 8120 4

    Total 3420 86258 25

    lbs P2O5 Applied

    Most P fertilizer was applied to corn land, mainly as starter fertilizer.

  • Soil Test P Distribution

    0%

    20%

    40%

    60%

    80%

    100%

    1 2 3 4 5 7 8

    Farm

    % o

    f acr

    es

    UVM ExcessiveUVM HighUVM OptimumUVM MediumUVM Low

    Soil test P distribution varies by farm; most had

    Soil test P distribution varied by farmMost farms had large acreage with low and/or high/excessive soil test P, showing need for improved manure and fertilizer allocation.

  • Soil Test P vs AU/Acre

    0102030405060708090

    100

    0 0.2 0.4 0.6 0.8 1 1.2 1.4

    Animal Units/ Acre

    STP:

    % H

    igh

    + Ex

    cess

    Soil Test P and Animal Density

    With 2 exceptions, % of fields testing high or excessive increased with animal density.

  • Dissolved Runoff P vs Soil Test P

    0 10 20 30 40 50 60 70Soil P, mg/kg (Mod. Morgan's)

    0.0

    0.1

    0.2

    0.3

    0.4

    0.5R

    unof

    f DR

    P, m

    g/L

    DRP = 0.0638 + 0.00519*STPR = 0.701

    Other research in VT showed that dissolved P in runoff increases with increasing soil test P (Tilley et al.).

  • P Index by Field (3 Farms)P Index: Farm 1

    0

    20

    40

    60

    80

    100

    120

    140

    Field

    P In

    dex

    Determination of P Index on 3 farms showed a wide range, most low to medium, some high, and only 2 very high (apply no P).

  • P Index: Farm 2

    020406080

    100120140160180200

    Field

    P In

    dex

    P Index: Farm 4

    0

    20

    40

    60

    80

    100

    Field

    P In

    dex

  • PSNT for Corn on 6 Farms

    0

    20

    40

    60

    80

    100

    120

    1401 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85

    Field

    NO

    3-N

    , ppm

    PSNT results showed many fields above the 25 ppm threshold (no more N needed) and many below (N recommended).

  • Crop Nutrient Applied - RecommendedBaseline Year

    Available N, Applied - Recommended

    -20

    -10

    0

    10

    20

    30

    40

    50

    60

    70

    1 2 3 4 5 7 8

    Farm

    N, l

    b/ac

    re

    P2O5, Applied - Recommended

    -20

    0

    20

    40

    60

    80

    100

    120

    140

    1 2 3 4 5 7 8

    Farm

    N, l

    b/ac

    re

    Nitrogen Phosphorus

    Averaged across fields, most farms were applying more N and P than recommended in the baseline year, showing an opportunity for reduced nutri