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 & Jerry’sSt. Alban’s Coop.Poulin GrainBourdeau Bros. of Middlebury

University of Vermont Extension8 Dairy Farmers

Funding from: Ben & Jerry’s, NE SARE, The Ben & Jerry’s 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 & Jerry’s 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*STPR² = 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 nutrient loading and potential cost savings.

Starter Fertilizer Demo

Demonstration trials on one of the cooperating farms showed an opportunity for decreased starter fertilizer rate with no effect on corn yield. (Project coordinator shown.)

What were the Impacts?

Feed Comparisons (Yr 2-Baseline)

Farm 1 2 3 4 5 6 8 Avg + -Milk lbs/hd/day 3.07 -5.29 2.65 5.70 2.05 0.25 1.00 1.35 6 1

MP supply (% of req.) 0.22 5.25 4.68 11.15 4.08 8.47 2.15 5.14 7 0Rumen N Balance g/hd/day -14.11 -2.29 -34.32 -51.62 -3.34 -42.43 2.45 -20.81 1 6Feed N Efficiency % 0.81 -1.51 1.60 1.58 -0.78 1.41 -0.45 0.38 4 3

Feed P Efficiency % 6.30 2.81 10.22 6.37 4.65 -0.85 7.39 5.27 6 1Diet P % -0.06 -0.04 -0.11 -0.10 -0.06 -0.01 -0.09 -0.07 0 7P supply (% of req) -18.13 -9.74 -28.39 -25.15 -13.61 1.81 -22.12 -16.48 1 6

Most farms showed improvement in milk production and several feed parameters in the implementation year (Year 2) compared to the baseline year.

Change in Nutrients Applied –Recomm: Year 2-Baseline

Farm 1 2 3 4 5 7 8 Avg + -N, lbs/A -10.0 -1.2 -12.0 -10.7 26.7 -34.7 27.1 -2.1 2 5P2O5, lbs/A 21.0 -33.3 14.3 -27.8 -22.2 -19.7 -33.5 -14.4 2 5

# of Farms

Five of seven farms reduced average N and P application rates to bring them closer to recommended rates.

Farm 8 Year 1 Year 2 DifferenceP2O5 lbs/acre 63.2 37.2 25.9Cost/acre $40.20 $26.27 $13.93

For 2002P2O5 Import Avoided (tons) 3.9Savings $4,197

Farm 7 Year 1 Year 2 DifferenceP2O5 lbs/acre 106.4 59.6 46.8Cost/acre $40.76 $28.83 $11.94

For 2002P2O5 Import Avoided (tons) 9.3Savings $4,765

Farm 2 Year 1 Year 2 DifferenceP2O5 lbs/acre 35.9 23.8 12.1 Prices used

Cost/acre $20.64 $13.69 $6.96 10-20-20 $230/ton7-27-27 $261/ton

For 2002 10-40-10 $283/ton

P2O5 Import Avoided (tons) 1.0 21-17-0 $240/ton

Savings $1,151 19-19-0 $240/ton

Corn Starter Comparison

Whole-farm Phosphorus Balance Change: Baseline to Year 2

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

Phosphorus Mass Balance - Year 2

0

10

20

30

40

50

60

70

80

90

100

1 2 3 4 5 6 7 8

FarmPe

rcen

t

% Retained% Converted

Change in Whole Farm Conversion Efficiency % (Year 2 minus Baseline)

-20

-10

0

10

20

30

40

1 2 3 4 5 6 7 8Perc

enta

ge C

hang

e

NP

Whole-farm conversion efficiency improved on most farms for phosphorus (7 of 8) and nitrogen (5 of 8).

OpportunitiesSuccessesCorn Starter PFeed PFeed N

PotentialsFertilizer N

PSNT

Cropping Strategy

Implemented practices reduced:Fertilizer P rate and cost (3 of 7).Feed (rumen) N excess (6 of 7)Diet P excess (6 of 7).

ImpactsExcess crop N and P reduced (5 of 7).Lactating Feed Efficiency improved for N (4 of 7) and P (6 of 7).Whole Farm Efficiency improved for N (5 of 8) and P (7 of 8).

Summary

Management tools that decrease excess nutrient supply improve net farm nutrient balance and profitability. Nutrient Conversion Efficiency and Balance are constrained by efficiency of biological processes and economics. Considerations in improving farm nutrient balance are farm information systems, quality control procedures and farm and supplier risk approach. Excess reduction requires accurate information, consistency and farm-supplier relationships capable of honestly assessing risk vs. gain. Farm P balances are more easily improved than N balances, partly due to increased risk of reduced performance with N.Nutrient accumulation depends more on management than on AU/acre.

CONCLUSIONS