Should I be Concerned About High Soil Test Levels on my Farm? Ohio Swine Symposium, February 11, 2015 Greg LaBarge, Field Specialist Agronomic Systems Ohio State University Extension labarge.1@osu.edu
How much water per day should a healthy adult living in a temperate climate drink? Men is roughly 3 liters Women is 2.2 liters The Institute of Medicine
As an Agronomist Manure is great for plant production Manure provides most (if not all) of the 16 essential elements for crop production Adds stable organic matter components Take advantage of moisture in liquids
Discussion How high is too high? Water Quality Crop production? Nutrient Balance Legislation
From both economic return and water quality there are two priority situations with phosphorus Fields that have a high soil test level As soil test are higher you lose nutrient use efficiency and more nutrient enters stream at edge of field Risk at fertilizer application Nutrient on the surface when a runoff producing rainfall event occurs (closer event is to application higher the loss)
Potential for DRP loss based on soil test Source: Sharpley, et.al. Journal of Environmental Quality 2001 30: 6: 2026-2036
Soil Test and Water Quality Ohio Edge of Field Study Source: Kevin King
Edge of Field Studies Soil silt loam, silty clay loam and clay loam Soil test range 9-380 ppm M3 Manure 12 sites (6 pairs) Tillage (No-till, strip till, conservation) Base line period
Edge of field study-year 1-2 Results
Why the Agricultural Focus? Back of the envelope calculations State Ohio Indiana Acres 3,806,780 821,540 Michigan 1,313,420 Total 5,941,740 Percentage Ag Ag Acres Lbs/A (EOF 1 Year) 72% 4,278,052 1.7 US Tons P (DRP) 3,636 P task Force non point US Tons 4,395
Tri-State Critical Level and Maintenance Limit Provide Target Range for Soil Test Nutrient Phosphorus (Bray P1) Crops in Rotation Cation Exchange Capacity (CEC) Critical Level Maintenance Limit Corn & NA 15 30 Soybean Wheat & Alfalfa NA 25 40 Potassium NA 10 100 130 NA 20 125 155
Crop Effects of High P and K Soil Test Values Phosphorus Zinc deficiency is seen on soils with high P levels especially where ph is more alkaline (6.5 or higher) Potassium Antagonism to uptake of several nutrient especially Magnesium (in forages) Forage nutrient imbalances Salt Injury
Zinc Deficiency Source: University of Illinois
Salt Injury Source: University of Delaware-Kent County
Nutrient Balance - a check of soil test results To calculate : beginning soil test and ending soil test for the period Crop yields off yield map or from weighed strips corresponding to soil test point Fertilizer/manure applied for period in lbs P205/acre Outcomes of Nutrient Balance Calculation How did soil test level change; did soil test level increase or decrease Did we apply more nutrient or less nutrient than crop removed? Is our sampling point reliable based on nutrient balance observed? What is the rate of soil test change; up or down as it relates to yield taken off and fertilizer applied?
Nutrient Balance Crop Removal Total Nutrient Removal From Grain and Forage Track trends in soil test value and yield response over time Fertilizer Added Total of Annual Fertilizer Application per Acre Crop Removal minus Fertilizer Added Change in Soil Value=Start-End Pounds of P205 to Change soil test 1ppm Nappanee Soil Type NW Ohio
Phosphorus and Potassium-Expected Soil Test Changes The buildup equations in the Tri-states 6 to 10 lbs./a of K2O are required to change soil test K one ppm (CEC interaction). 20 lbs./a of P2O5 to change soil test P levels one ppm.
Phosphorus Crop Removal Rates Crop Unit of Yield Removal Rate P 2 O 5 in lbs. per bushel 2013 Ohio Yield 2013 Removal Rate P 2 O 5 in lbs. Corn bushel 0.37 174 64 Corn Silage ton 3.30 28 92 Soybeans bushel 0.80 49 39 Wheat-Grain bushel 0.63 63 40 Wheat-Straw bushel 0.09 63 6 Alfalfa ton 13.00 3.5 46
Potassium Crop Removal Rates Crop Unit of Yield Removal Rate K 2 O in lbs. per bushel 2013 Ohio Yield 2013 Removal Rate K 2 O in lbs. Corn bushel 0.27 174 47 Corn Silage ton 8.00 28 224 Soybeans bushel 1.40 49 69 Wheat-Grain bushel 0.37 63 23 Wheat- bushel 0.91 63 60 Straw Alfalfa ton 50.00 3.5 175
Nutrient Balance- Bi-Annual Application
Nutrient Balance- Annual Application
Swine Finishing (3) 2002 Total Acres under Center Pivot = 103 acres Total Annual Rate under Pivots = 30,000 gallons Manure Analysis lbs per 1,000 gallons NH4 Organic N P2O5 K2O 6.3 lbs 2.2 lbs 2.7 lbs 18.8 lbs Total K2O applied per acre per year = 564 lbs. Total P2O5 applied per acre per year = 81 lbs Site: 1 2 3 K Level (ppm) 303 560 345 TEC 15 15 16
Potassium Levels under Manure Irrigation Swine Farrowing(1) 2003 Total Acres under Center Pivot = 53 acres Total Annual Rate under Pivot = 108,000 gallons Manure Analysis lbs per 1,000 gallons NH4 Organic N P2O5 K2O 4.64 lbs 0.25 lbs 0.41 lbs 7.29 lbs Total K 2 O applied per acre per year = 787 lbs. Total P 2 O 5 applied per acre per year = 44 lbs Soil Test Values Center Pivot Field divided into 4 quads Site: 1 2 3 4 K Level (ppm) 244 402 745 902 TEC 22 19 19 16
High Soil Test Fields- Legacy Fields Phosphorus Soil Test Value Annual Removal P 2 O 5 250 bu Corn Crop Annual Soil Test reduction in ppm Years to Critical Level 15 ppm 1000 ppm 92.5 4.6 214 300 ppm 92.5 4.6 60 200 ppm 92.5 4.6 40 150 ppm 92.5 4.6 30 80 ppm 92.5 4.6 14 50 ppm 92.5 4.6 8
Potential for DRP loss based on soil test Source: Sharpley, et.al. Journal of Environmental Quality 2001 30: 6: 2026-2036
Edge of field study-year 1-2 Results
What's next with legislation?
Legislation Ohio Ag Pollution Abatement Laws-Sediment Bound Nutrient Ohio Permitted Livestock Facilities-Environmental impact (2014) House Bill 150- Established Agricultural Fertilizer Applicators Certification by 9/30/17 and Affirmative Defense against civil law suite process. (2015 Proposed) Senate Bill 1 Application Conditions Criteria 2015 Bloom, then what???
Summary Manure is a great source of nutrients, that when used in an agronomic way, can lower fertilizer purchases. Look at manure application logistics and plan out based on soil test levels strategies to take the greatest advantage. When soil test levels are built up beyond agronomic needs the risk of off site movement increase dramatically. There will be another round of legislation in 2015, it will most likely affect application field conditions. What is next when the algae bloom happens in summer 2015?
Questions? For More Information http://agcrops.osu.edu/specialists/fertility Greg LaBarge Field Specialist, Agronomic Systems labarge.1@osu.edu