Managing P & N Nutrient Resources Agronomy In-service January 3, 2013 Greg LaBarge, Field Specialist, Agronomic Systems

Discussion Why be concerned with nutrient/sediment Phosphorus –What do we want farmers to do –Tri-state Philosophy and Status Nitrogen –Economic rate calculator Other Issues

Why be concerned about nutrients/sedimentation leaving edge of field? Water Quality Concerns in water bodies –EPA water quality measured as “intended use” –Regulation Ohio Ag Pollution Abatement from “manure and sediment bound nutrients” to “nutrients” –Sedimentation removal Cost Maumee and Harbor ($5,000,000 annual) Good Stewards and Public Pressure Economic Cost (Loss) of Nutrients

Value of Nutrient In Maumee River Average value of nutrient lost WY –based on $650 per ton P 2 O 5 & $0.65 cent Nitrogen NutrientValue Phosphorous$ 4,129,291 Nitrogen (Nitrate)$39,694,230 Total$43,823,521 Per acre$13.52

Phosphorus Soil reactions of phosphorous Nutrient Movement What do we want farmers to do Do the tri-state recommendations still work Recommendation resources

Three Important Soil P Fraction for Plant Nutrition Soil Solution Labile P Nonlabile P

Nutrient Movement Solution P H 2 PO 4 - HPO 4 2- <0.3 ppm Solution P H 2 PO 4 - HPO 4 2- <0.3 ppm Adsorbed P Labile P Secondary Minerals Fe/AlPO 4 CaHPO 4 Nonlabile P Primary Minerals Nonlabile P Organic Matter Bound P Nonlabile P Fertilizer Manure Adsorption Desorption Dissolution Precipitation Dissolution Mineralization Immobilization Plant uptake Leaching Total P in soil – ppm ~ lb/acre Labile P Leaching

Water Definitions Total Phosphorus "Total" phosphorus is largely defined on the basis of how much phosphorus in its various forms will be oxidized into orthophosphate by a specific oxidant. Water soluble P –Dissolved reactive phosphorus (DRP) –Bioavailable Phosphorus The soluble form of the nutrient phosphorus, which is readily available for use by plants. consist largely of the inorganic orthophosphate (PO 4 ) form of phosphorus. Particulate P Soil attached P

Source: Heidelberg University

Maumee River Gauging Station Source: Hiedelberg University

Increased DRP? Increased broadcast applications –Time required for nutrient to attach to sites –Stratification and preferential flow No-till Time needed to re-establish preferential flow after tillage Soil tests levels –STL are in decline & P fertilizer sales are declining Tile increased intensity Rotation changes Size of farm

Nutrient Movement Can they move? –Yes. Largest deciding factors are soil texture and nutrient concentration (tillage is a factor as well, obviously) Boem et al., SSSAJ, 2008

Nutrient Movement Nutrient concentration causing nutrient leaching Mehlich-3 soil P, mg/kg Dissolved P, mg/L Drainage from 50-cm undisturbed soil lysimeters

Discussions agricultural reductions Five month public process 100 plus individuals involved Final report us/portals/12/docs/water qualityreport.pdf

What contribution to reduction can agriculture make? 4R Nutrient Stewardship –‘Right’ Rate, ‘Right’ Timing, ‘Right’ Placement & ‘Right’ Source Industry Developed Program –Global – Goals –Increase crop production & improve profitability –Minimize nutrient loss & maintain soil fertility –Ensure sustainable agriculture for generations to come

Additional In-service For More Information:

Recommendations to Reduce Nutrient Movement off -site The ‘Right’ Rate. –Good representative soil sample should be the basis for fertilizer application. –Utilize Ohio State University Extension Agronomic Recommendations for nutrient application. –Records should be kept for all soil tests, recommendations and applications as well as crop and resulting yields. – sheets-and-bulletinshttp://agcrops.osu.edu/specialists/fertility/fertility-fact- sheets-and-bulletins Source: Ohio Director’s Working Group on Ag Nutrients 4/12

Fertility Rates

Critical Level “…the soil test level above which the soil can supply adequate quantities of a nutrient to support optimum economic growth.” Below the CL”…the soil is not able to provide P and K requirements of the crop.” Above the CL”…the soil is capable of supplying the nutrient required by the crop and no response to fertilizer would be expected.”

Critical Level CropP- Bray 1 (PPM) P- Bray 1 (lbs/A) Corn & Soybeans1530 Wheat & Alfalfa2550

218/23/2015 Spatial Variation Soil test P

228/23/2015 Nutrient Distribution Mean soil test P – 18 ppm Median soil test P – 16 ppm

Maintenance Plateau Range “Designed to replace nutrient lost each year through crop removal.” “…no response to fertilizer in the year of application expected.” “No response to placement technique such as banding or stripping or the use of P and K starter fertilizer…”

Corn

Maintenance Limit CropP- Bray 1 (PPM) P- Bray 1 (lbs/A) Corn & Soybeans3060 Wheat & Alfalfa4080

Drawdown “When soil test levels exceed maintenance plateau level (Maintenance Limit), the objective of the fertilizer recommendation is to utilize residual soil nutrients….There is no agronomic reason to apply fertilizer when soil test are above the maintenance plateau level.”

Drawdown CropP- Bray 1 (PPM) P- Bray 1 (lbs/A) Corn & Soybeans4080 Wheat & Alfalfa50100

Corn

"What do you mean do not put any P on, won't my soil test drop?" Two part answer. First yes, soil test levels will drop, but if you are above the crop response range for the crop it really is not a problem crop production wise. If you are above 30 PPM there is no yield benefit and if you are way above this level there is an economic benefit to using this soil stored P.

"What do you mean do not put any P on, won't my soil test drop?“ Part 2 The second part of the answer is soil test do not drop 1 to 1 with crop removal. A 150 bushel corn crop removes (150 bushel * 0.37 Crop removal = 56 lbs). Phosphorous chemistry in the soil buffers the crop removal so that for each lbs of P2O5 removal phosphorous levels in the soil are lowered 1 PPM. So our 150 bushel crop will lower the soil test at around 3-4 PPM.

Expected Soil Test Changes The buildup equations in the Tri-states 20 lbs./A of P2O5 to change soil test P levels one ppm. 6 to 10 lbs./A of K2O are required to change soil test 1 ppm depending upon the soil CEC.

Equations BUILDUP EQUATION for P: lb P 2 O 5 /A to apply = [(CL - STL) x 5] (YP x CR) MAINTENANCE EQUATION for P: lb P 2 O 5 /A to apply = YP x CR DRAWDOWN EQUATION for P: lb P 2 O 5 /A to apply = (YP x CR) - [(YP x CR) x (STL - CL 15))/10] CL = critical soil test level (ppm) STL = existing soil test level (ppm) YP = crop yield potential (bu per acre for grains, tons per acre for forages) CR = nutrient removed per unit yield (lb/unit) CEC = soil cation exchange capacity (meq/100g)

Recommendation Resources

Recent looks at Tri-state Critical Values Dr. Jay Johnson study at Western Branch relative yield without fertilizer 2006-present. Dr. Robert Mullen study at Western, Northwest and Wooster fertilizer at 0, 1X, 2X rate based on tri-state

Critical Levels Ohio State data – relative corn yield and STP Critical Value – 30 lb/ac

Critical Levels Ohio State data – relative soybean yield and STP Critical Value – 30 lb/ac

Iowa

Are Current Critical Levels Still Valid? Northwest Research Station near Custar, Ohio Initial soil test levels –P – 39 ppm; K – 272 ppm; CEC – 24 meq/100 g –Critical levels – 15 ppm (P) and 135 ppm (K) Would you expect much response at this location?

Are Current Critical Levels Still Valid? Phosphorus response in corn-soybean rotation

Are Current Critical Levels Still Valid? Phosphorus response in corn-corn-soybean rotation

Are Current Critical Levels Still Valid? Western Research Station near Springfield, Ohio Initial soil test levels –P – 20 ppm; K – 102 ppm; CEC – 14 meq/100 g –Critical levels – 15 ppm (P) and 110 ppm (K) Would you expect much response at this location?

Are Current Critical Levels Still Valid? Phosphorus response in corn-soybean rotation

Are Current Critical Levels Still Valid? Phosphorus response in corn-corn-soybean rotation

Are Current Critical Levels Still Valid? East Badger Farm near Wooster, OH Initial soil test levels –P – 17 ppm; K – 109 ppm; CEC – 11 meq/100 g –Critical levels – 15 ppm (P) and 103 ppm (K) Would you expect much response at this location?

Are Current Critical Levels Still Valid? Phosphorus response in corn-soybean rotation

Are Current Critical Levels Still Valid? Phosphorus response in corn-corn-soybean rotation

Other Rate Considerations Product Margin vs Service Consider all nutrient sources

Other Rate Considerations Precision Application –Sampling scheme –Variable rate across field Goal Even levels across field-good for pH Application rate based on crop response

Other Rate Considerations Rented vs Owned –Fertility Levels –Structures

Recommendations to Reduce Nutrient Movement off -site The ‘Right’ Time. –Nutrients should not be applied to frozen or snow covered ground. –Nutrients should be applied as close to crop utilization as possible. –Or if not applied close to utilization practices should be used to keep it in forms that limit movement offsite Source: Ohio Director’s Working Group on Ag Nutrients 4/12

Recommendations to Reduce Nutrient Movement off -site The ‘Right’ Place. –Phosphorous applications should be injected or incorporated whenever possible. –If surface applications are made, it should have a growing crop or cover as soon as possible. Source: Ohio Director’s Working Group on Ag Nutrients 4/12

Mullen, 2011, unpublished Rainfall simulator study, NW Ohio, Nov 2009 P sources applied at 80 lb P 2 O 5 per acre Total P loss < 2% of amount applied 2.4”/hour; first 30 minutes runoff

Placement Row Starter Foliar Strip Tillage Other banded application Incorporation

Recommendations to Reduce Nutrient Movement off -site In addition to the 4 R’s- Improve Soil Quality. –Soil organic matter. –Soil compaction. –Water infiltration rates. –Methods to reduce runoff. Source: Ohio Director’s Working Group on Ag Nutrients 4/12 Source:

Tiling

Blind Inlets

Contribution

Recommendations to Reduce Nutrient Movement off-site In addition to the 4 R’s- Improve Water Management and Possible Treatment of Drainage Water. –Repair broken subsurface drainage. –Treating surface inlets runoff into subsurface drainage systems. –Treating concentrated surface runoff areas. –Controlled drainage. –Constructed wetlands for treatment –Improved designed filtered areas, biofilters –Alternative drainage ditch designs Source: Ohio Director’s Working Group on Ag Nutrients 4/12

Nitrogen Recommendations

Relationship between yield level and agronomic optimum N rate in Ohio (90 sites – corn after soybeans) 628/23/2015

Nitrogen Recommendations So… Land Grant Universities (in the Midwest) have moved away from yield goal based recommendations as a result of this information What are we left with? It’s a risk model, what is the risk of a certain N rate with regard to agronomic performance while considering the economic factors 638/23/2015

Where we are today with new recommendations Where I think we should go? Using the above template, evaluate different sources, timings, and methods of N application to define risk of yield loss at various N rates Lots of data yet to be collected Where we are today with new recommendations Where I think we should go? Using the above template, evaluate different sources, timings, and methods of N application to define risk of yield loss at various N rates Lots of data yet to be collected Nitrogen Recommendations 648/23/2015

Economic Nitrogen Rate Calculators Mullen Developed ertility-fact-sheets-and-bulletins Will be updated by 3/1/ ertility-fact-sheets-and-bulletins Iowa State (houses midwest verson) y/nrate.aspx y/nrate.aspx

Iowa Site

Other Issues NRCS 590 Nutrient Management and 633 Manure Nutrients was combined into one 590 standard NRCS CAPS (Conservation Activity Plan) –102 Comprehensive Nutrient Management Plan –104 Nutrient Management Plan –Systems Soil testing, precision application, cover crops, controlled traffic, strip tillage echnical/tsp/

Summary Building case for better nutrient management-economic and environmental Tri-state Philosophy –Tri-state P & K Recommendations are sound What do we want farmers to do: –4R Nutrient Stewardship Introduction to Nitrogen –This is an area we need to more in moving forward. Economic implications are greater.