Overview of Nitrogen and Phosphorus Flow Across — and Balance through — A Dairy Operation

1. Overview of Nitrogen and Phosphorus Flow Across — and Balance through — A Dairy Operation M. A. Wattiaux Department of Dairy Science

2. Purchased Feed Purchased Fertilizer Stored Feed Environment (air & water) Crops (Pastures) Livestock Soil Manure Manure Sold Milk/Livestock Sold Crop Sold Livestock - Soil - Crops Environment Farmgate (“Balance”)

3. Herd Herd ? ? Crop Crop Environ. Impact Environ. Impact Herd Herd ? ? Crop Crop Environ. Impact Environ. Impact Activity:Please discuss the “risk” of pollution associated with each of the following farm conditions for N and P. A) Few Cows - Few Crop Acres B) Few Cows - Lots of Crop Acres C) Lots of Cows - Few Crop Acres D) Lots of Cows - Lots of Crop Acres

4. Combined costs of production of crops, feed purchased and manure spreading2 ($/year) Percent of manure that cannot berecycled by the crops. Cow per hectare (c/ha) Cow per hectare (c/ha) 2 Adjusted for the sale of crops when cow/hectare is less thana 1.0. “Balance” between crops and herd size N-CyCLE simuation results for a 100-cow herd with cropping land varying from 200 hectares (c/ha = 0.5) to 16.7 ha (c/ha = 6.0) 1 Wattiaux and Pellerin, unpublished (http://dairynutrient.wisc.edu)

5. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

6. Animal Scientist Crop Scientist Animal Efficiency - Nutrition - Breeding - Management - Etc. Crop Productivity - Fertilization - Selection - Management - Etc. Soil Scientist • Soil Type • Soil Structure • Erosion control • Nutrient flow • Etc. Traditional Approach to “Solving Problems”:Disciplinary Views1 1 From a research, extension or Instruction point of view

7. Animal Scientist Crop Scientist Nutrition determines amount and composition of manure Manure impacts crop fertilization plan Soil Scientist Manure influences soil characteristics and risk of erosion. Manure Management:Disciplinary Views1 1 From a research, extension or Instruction point of view

8. Manure Management:Integrated (Farmer’s) View1 Animals Crops Soils 1 From a research, extension or Instruction point of view.

9. Vision of the “nutrition consultant” Feedpurchased Dairy Herd Forages

10. Fertilizer Purchased Vision of the “crop consultant” Forages Corn Alfalfa

11. Feed purchased Dairy Herd Silo Forages Manure Fertilizer purchased Corn Alfalfa The missing link What is missing?

12. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

13. International / Global Nitrous Oxide (N2O) Methane (CH4) Ammonia (NH3) Regional / National Volatiles Organic Compounds (VOC) Watershed Ammonia (NH3) Sulfure dioxide (H2S) other malodoferous compounds Farm Ammonia (NH3) Crops Soils Livestock Why? 1- Scale of Environmental Issues

14. Emphasized interactions rather than “main effects.” Integrate knowledge of various disciplines to solve “real-world” problems. Improved ability to modify system’s “behavior” in order to reduce environmental impacts and, at the same time, improve farm profitability. Study the herd & crop as a single unit of management. Scientific method of the disciplinary researcher (experimental research - hypothesis testing) vs. scientific method of the system researcher (“soft” system analysis vs. mathematical models and other “quantitative” tools). Lack of modeling skills and expertise. Little commercial interest (feed, fertilizer, supply, equipment, etc.). … Other Reasons to Advocate for System Research? Why isn’t it happening?

15. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

16. Introduction: What Is a “System”? • A “SYSTEM” is defined as: • an entity with boundaries or limits (physical or conceptual)… • made of internal interacting components, … • organized to complete a function (i.e., has a goal), and… • characterized by a set of relations with the “external” world (emerging properties from one level to the next).

17. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

18. Wu et al., 2000 J. Dairy Sci. 83:1028-1041 “Traditional” Research = Hypothesis Testing Cause Effect Independent variable Dependent variable

19. What is “System” Analysis?What is “Modeling”

20. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

21. Feeds Bedding Milk Animal Manure Crops Fertilizer Imported Exported Modeling Whole-Farm Nutrient Balance Balance = Imports - Exports

22. Dairy Herd sub-model Feed Harvesting & Storage (Bedding) Manure Collection & Storage Water Air Soil Sub-model Crops Modeling Whole-Farm Nutrient Cycling

23. Dairy Herd sub-model Feed Harvesting & Storage (Bedding) Manure Collection & Storage Nutrient not recycled Soil Sub-model Crop Balance = Imports - Exports Modeling Nitrogen Cycling and Balance Feeds Bedding Milk Animal Manure Crops Fertilizer Imported Exported

24. US1 NE2 NZ3 P - Metric Tons per year 6.1 3.3 7.2 1.0 0.7 10.9 15.8 3.6 0.7 14.9 0.0 26.9 -- -- -- 0.0 0.0 0.3 0.0 0.0 16.9 46.0 11.1 1.7 15.6 3.6 18.2 3.6 0.6 3.1 0.0 0.0 0.2 0.0 0.0 0.5 0.0 0.8 0.1 0.0 4.1 18.2 4.6 0.7 3.1 12.8 27.8 6.5 1.0 12.4 25 40 41 44 20 2NE : The Netherlands : 114 farms, 71 cows, 41 ha 3NZ : New Zealand : 5 farms, 666 cows, 222 ha Nutrient Balance in Dairy Farms from three Countries US1 NE2 NZ3 N - Metric Tons per year Imports Feeds 25.2 Fertilizers 8.3 Biological Fixation N 21.5 Other 0.4 Total 55.4 Exports Milk 18.4 Crops 4.1 Manurel 1.0 Total 23.6 Balance (Metric tons yr-1) 31.8 Efficiency (%,100*Exp./Imp.) 43 1US : 28 dairy farms in Wisconsin, 289 cows, 255 ha

25. 186 kg N consumed1 100% 18% - 30% 45 kg N Milk 141 kg N Manure 76% 28 kg N Ammonia (collection & storage) 113 kg N Applied 30% - 45% 61% 46% 27 kg N Ammonia (no incorporation) 86 kg N in Soil 52 kg N Organic Matter 34 kg NPlant Available (Ammonia or nitrate) Leaching Nitrate 18% 1 One dairy cow producing approximately 9,000 kg of milk per year. Eficiency of Nitrogen Utilization Modified from Satter, 2001

26. 21.9 kg P consumed1 100% 25% - 42% 9.1 kg P Milk 12.8 kg P Manure 58% 0 kg P volatilized (collection & storage) 12.8 kg P Applied 60% - 80% 58% 58% 0 kg P volatilized 12.8 kg P in Soil Runoffs (Erosion) 5.1 kg P Soluble and/or adsorbed to clay particles 7.7 kg P Plant Available (18 kg P2O5) 35% 1 One dairy cow producing approximately 9,000 kg of milk per year. Efficiency of Phosphorus Utilization

27. Outline • Solving problems: disciplinary vs. systems research • Why should we do systems research (systems analysis)? • What is a “system”? • Introduction to “system research” (system’s analysis)? • “Whole-farm” system: nutrient balance and recycling • Biological response vs. economic response to nutrients

28. Milk production (kg/c/y) 1- Product price 2- input price 3- response curve Crop yield (kg/ha/y) Biological Maximum Economic Optimum Concentrate, kg/c/d Nitrogen, kg/ha/y Biological Maximum vs. Economic Optimum What factors determine the economic optimum?

29. Primiparous cows Multiparous cows Conc.2 Milk3 Conc.2 Milk3 F/C1 kg/d kg kg/d kg 98 / 02 0.3 4750 0.4 6000 87 / 13 2.2 6013 2.7 6849 73 / 27 4.9 6976 5.7 7563 64 / 36 6.4 7177 8.1 8659 53 / 47 8.7 7334 10.2 8295 1 Percentage of forage and concentrate in the dry matter portion of the ration. 2 Average amount of concentrate dry matter offered daily over the entire lactation. 3 Average milk production adjusted to a 365-day basis. Milk Production Response to Concentrate Feeding Average milk production, kg/c/d Average concentrate offered, kg /c/d Modified from Tessmann et al., 1991.

30. Marginal response1 Cost Marginal Revenue Quantity per day marginal Price revenue per day Pesos/d Pesos/kg Kg / kg Con. Pesos/kg Pesos/kg Con. Kg/d Pesos/d 2.75 2.75 1.48 4.00 5.93 1.48 5.93 5.50 2.75 1.35 4.00 5.39 2.83 11.32 8.25 2.75 1.22 4.00 4.86 4.05 16.18 11.00 2.75 1.08 4.00 4.33 5.13 20.51 13.75 2.75 0.95 4.00 3.80 6.08 24.31 16.50 2.75 0.82 4.00 3.26 6.89 27.57 19.25 2.75 0.68 4.00 2.73 7.58 30.30 22.00 2.75 0.55 4.00 2.20 8.12 32.50 24.75 2.75 0.42 4.00 1.66 8.54 34.16 27.50 2.75 0.28 4.00 1.13 8.82 35.30 30.25 2.75 0.15 4.00 0.68 8.97 35.90 1 According to the response curve presented in the previous slide. Economic optimal Biological maximal What is the Optimal Amount of Concentrate? Concentrate Milk Quantity Kg/d 1 2 3 4 5 6 7 8 9 10 11

31. Economic Optimal What is the Optimal Amount of Concentrate? Milk sale Concentrate Cost Pesos / d Profit Concentrate, kg dry matter /d

32. Good 4.00 2.00 8.3 >11 6.8 8.0 4.00 4.00 4.8 >11 5.0 8.0 Good Good 2.50 2.75 4.0 >11 4.5 8.0 4.50 2.75 7.5 >11 6.3 8.0 Good Poor 4.00 2.00 4.5 ? 5.0 ? 4.00 4.00 1.0 ? 3.3 ? Poor Poor 2.50 2.75 0.8 ? 3.0 ? 4.50 2.75 3.8 ? 4.5 ? Poor 1Good = Expected response (mean of 1.48 kg milk / kg of concentrate). 2 Poor = Expected response minus 0.5 kg (mean of 0.98 kg milk / kg of concentrate) Response Curve: “Quality of Management” Price Concentrate, kg dry matter / d Multiparous Primiparous Milk Peso/l Conc. Peso/kg Mangmt1 Econ. Opt. Biol. Max Econ. Opt. Biol. Max.