Manure 101 Nutrient Management and the Dairy Industry

Manure 101: Nutrient Management and the Dairy Industry. Kevin Erb UW-Extension NPM Program University of Wisconsin - Extension UW-Madison College of Agricultural & Life Sciences

Farmer View of Site-Specific Future Manure Regulations

What is Nutrient Management? Common Sense. n Combine on-farm nutrient sources, with commercial fertilizer, to meet crop need. On-farm nutrient sources (manure) Soil reserves Commercial fertilizer Minimize nutrient losses

Environmental Aspects of Manure n Nutrients n Nitrogen n Phosphorus n Potassium n Bacteria/Pathogens n BOD

Nitrogen n Groundwater Concerns n EPA Standard: 10 ppm n Blue Baby Syndrome n Hypoxia

Hypoxia

Phosphorus n Surface Water Concern n Algae Growth

Environmentalist’s view of how farmers manage manure.

Phosphorus n Movement n Soil attached is most common route n n 1 lb P = 500 lb algae One ton soil eroded = 1 ton algae in water n Stop Erosion, Solve Big Part of the Problem n National Buffer Initiative (USA)

Potassium n Dairy Animal Health Concern n Too Much in Ration: Ketosis / Milk Fever

Bacteria n E. Coli n Up to 6 month + viable in soil n Does not survive as well on surface n Enters streams when manure runs off

Antibiotics n Animals DO NOT break them down. n Excreted intact with the urine n Low level resistance concerns

Biochemical Oxygen Demand * A measure of how much oxygen is removed from a water body by the bacteria breaking down organic materials. (BOD) Chemical Oxygen Demand (COD) * Oxygen required to break down chemical compounds in water body.

Manure Basics n What is Manure? n Urine, feces n Waste feed n Parlor water n Gray water (sinks, etc)

Manure Basics n How Much Manure Does a cow produce in a day? A week? A Month? A Year?

The Influence Of Milk Production On Daily Manure Production

How Much Manure? n Typical Dairy Cow: n 148 lbs/day (18 gal) n 1036 lbs/week (124 gal) n 4440 lbs/month (531 gal) n 54020 lbs/year (6460 gal) n Does not include youngstock, other wastes

Rule of Thumb #1 n One cow plus replacement plus wastewater = 10, 000 gal/year

What is in manure? n Nutrients n Nitrogen, Phosphorus, Potassium n Micro nutrients (Sulfur, Boron, etc) n Whatever the cow eats that does not become milk or meat becomes manure. n If it’s in the feed, it’s in the manure.

Dairy Diet and Runoff Manure from 2 rations applied n 1. 28 and 0. 48% P (rec is 0. 34 -0. 38) n n Runoff was 4 x higher for high P diet n Same n lbs P applied Runoff was 10 x higher when manure rates were the same. n Ebeling et al, 2001

Dairy Diet Impacts n Ave P in dairy ration is 0. 47% n Gunderson, Keuning & Erb, 2001 n NRC Recommendation is 0. 32 -0. 38% P n Higher rates are due to belief that lower P reduces reproductive efficiency.

The Manure Paradox Crops use N: P: K in a 3: 1: 2 ratio Dairy manure is a 1: 1: 2 ratio (available) Meet the crop’s N need = excess P Meet the crop’s P need = buy N fert

Manure Nutrient Content - Dairy ___________________ N P 2 O 5 K 2 O (surface/incorporated) Solid (lb/ton) ___________ 3/4 3 8 Liquid (lb/1, 000 gal) 8 / 10 8 21 ___________________

Crop Nutrient Removal N P 2 O 5 K 2 O - - - - - lb/a/yr - - - - Corn (160 bu/a) Corn silage Soybean Alfalfa (23 ton/a) (40 bu/a) (5 ton/a) Reed canarygrass 160* 60 40 225 90 170 115 35 40 250 65 250 125 325 (5 ton/a) *recommended application rate. Note that these numbers vary by state/prov.

Example of P 2 O 5 Recommendations for Corn Yield Goal bu/a Soil Test Level Low Optimum High Ex. High - - - - lb/acre - - - - 111 -130 131 -150 151 -170 65 75 80 45 55 60 25 25 30 0

Corn Nutrient Need vs. Manure Nutrient Supply Following a Nitrogen Strategy l cre b/a

Manure Application Rates Nitrogen Strategy n Maximum rates n P and K in excess of crop need n Efficient with time and labor n Preferred when land is limited

Corn Nutrient Need vs. Manure Nutrient Supply Following a Phosphorus Strategy cre b/a l

Manure Application Rates Phosphorus Strategy n Low rates n Need supplemental nitrogen n Increased time and labor n Need adequate acreage

Manure Nitrogen Content Total vs. Available Solid Manure lb N/ton

Soil Test P Changes Slowly n Soil buffering capacity n The amount of fertilizer needed to change the soil test level by 1 ppm n 18 lbs P 2 O 5/acre = 1 ppm change in soil P n Time is required to either lower or raise soil test levels.

Soil Test P Changes Slowly - Example Soil test P = 75 ppm (EH) n Track draw-down of P over a CCOHHH rotation. n

Soil Test P Changes Slowly - Example n n Soil test P = 75 ppm (EH) Track draw-down of P over a CCOHHH rotation. n n Oats @ 100 bu/a removes 25 lb P 2 O 5/a/yr n n Corn @150 bu/a removes 55 lb P 2 O 5/a/yr Alfalfa @ 5 tons/a removes 65 lb P 2 O 5/a/yr Removal of P 2 O 5 over rotation = 330 lbs P 2 O 5

Soil Test P Changes Slowly - Example n n n Soil test P = 75 ppm (EH) Track drawdown of P over a CCOHHH rotation. Removal of P 2 O 5 over rotation = 330 lbs P 2 O 5 Change in soil test P = 330 lb P 2 O 5/18 = 18 ppm P

Soil Test P Changes Slowly - Example n n Soil test P = 75 ppm (EH) Track drawdown of P over a CCOHHH rotation. Removal of P 2 O 5 over rotation = 330 lbs P 2 O 5 Change in soil test P = 330 lb P 2 O 5/18 = 18 ppm P Soil test P = 57 ppm (EH) after the 6 -year rotation. (75 ppm P - 18 ppm P = 57 ppm P)

Regulations n 1972 Clean Water Act n Point vs. Non-Point Sources n Problem Not Yet Solved.

Regulatory Future Each Providence, State, County, Township may be different. n Future n n Lower AU (animal unit) threshold for permit n More phosphorus emphasis n Future emphasis on bacterial / antibiotics / odor concerns n Short term focus will be on P based nutrient management

Economics (Nitrogen @ $0. 20/lb) 100 Cow Dairy Alfalfa N = $ 1, 200 (50 acres/yr @ 120 lbs N/a) Manure N = $ 1, 320 (22 tons/cow/year @ 3 lbs N/ton) Total On-Farm N = $ 2, 520

Economics (P 2 O 5 @ $0. 25/lb; K 2 O @ $0. 13/lb) 100 Cow Dairy Manure P 2 O 5 = $ 1, 650 (22 tons/cow/year @ 3 lbs P 2 O 5/ton) Manure K 2 O = $ 2, 288 (22 tons/cow/year @ 8 lbs K 2 O/ton) Total Manure P 205 & K 2 O = $ 3, 938

If You Are Going To Use Manure as a Fertilizer… Treat It Like A Fertilizer!

Soil Test Phosphorus Variability from a Wisconsin Dairy Farm

Public Relations n Manure Handling and Application n Odor control n Real or perceived excessive rates n Road spillage n Traffic hazards & delays n Spreading near water n Cattle in water

Challenges of the Future: n Dairy Trends. n Management: More cows, fewer farms. n Realization by farmers that manure management requires a cash investment. n Manure’s Internet IPO: Lots of ideas now, lots of broken ideas coming in a few years. Easiest to use / most farmprofitable techniques will remain.

Opportunities of the Future: n Every farm will have a nutrient management plan. n Nitrogen – Phosphorus Pendulum n Affiliated and independent consultants n Site-specific research n Between 1992 and 2001, UWGB was the lead institution for mass balance research.

Farmers are searching for answers. Manure is no longer considered the last item after everything else is done.

kevin. erb@ces. uwex. edu