An update for nutrient recommendations for Ohio's major field crops (corn, soybean, wheat, and alfalfa) was published in 2020 as the Tri-State Fertilizer Recommendations for Corn, Soybean, Wheat, and Alfalfa. This fact sheet builds on that information, and expands it to include recommendations for other agronomic crops grown in Ohio.
The current philosophy in Ohio for crop nutrient management is to apply phosphorus (P) and potassium (K) fertilizer or manure equivalent at crop removal rates. Additionally, if soil test levels of P and K are below the critical level, then a "Buildup" recommendation would be considered to increase soil test levels into the "Maintenance" range.
The values in Table 1 are the averages for the crops listed and were gathered from neighboring state and national databases. See the References section of this fact sheet for a list of sources.
- See Table 2 for the maintenance ranges and Table 3 for calculating new fertilizer recommendations. Once in the maintenance range, crop removal would be the recommendation for P2O5; the K2O recommendation would be crop removal plus 20 lbs/A of additional K2O. If soil test levels are at or above their respective maintenance limit, then no further P2O5 or K2O would be applied.
- As stated above, these values are averages for the crop named. For more accurate numbers for a particular area and crop, send a sample to a lab for testing and use that value for crop removal.
- Critical soil test levels have not been recently evaluated for the additional crops beyond corn, soybean, wheat, and alfalfa listed in this fact sheet. It is reasonable to assume that critical soil test values used for crops listed here, and in the updated Tri-State Fertilizer Recommendations, can be used as guidance for the small grain or forage crops listed in Table 2.
- The nitrogen (N) recommendations for Ohio field crops come from several sources. Generally, these recommendations are based on yield goal, economics, or previous crop—not on crop removal for nitrogen, as shown in Table 1.
- No tables are shown for vegetable crops. Please use the information found in the Resources section of this fact sheet.
|Crop||Average nutrient removal|
|Cool-season grass hay||lb/ton||35.4||12.0||48.1|
|Corn silage1 35%DM||lb/ton||3.1||7.3|
|Mehlich-3 Potassium Maintenance Range|
|Crop||Mehlich-3 Phosphorus||Sandy soils||Loam and clay soils|
|Maintenance Range||(CEC <5 meq/ 100g)||(CEC >5 meq/ 100g)|
|Corn (grain or forage), Soybean||20–40 ppm||100–130 ppm||120–170 ppm|
|Wheat, Alfalfa||30–50 ppm||100–130 ppm||120–170 ppm|
|Phosphorus (lbs P2O5/ acre to apply)|
|Maintenance range||Yield × Nutrient Removal|
|Build-Up range||(Yield × Nutrient Removal) + [(CL – STP) x 5]|
|Potassium for Indiana and Ohio (lbs K2O/ acre to apply)|
|Maintenance range (grain crops)||(Yield × Nutrient Removal) + 20|
|Maintenance range (forage crops)||[(Yield × Nutrient Removal) + 20] - [((Yield × Nutrient Removal) + 20) x (STK – CL)/50]|
|Build-Up range||[(Yield × Nutrient Removal) + 20] + [(CL – STK) × (1 + (0.05 x CEC))]|
|Potassium for Michigan (lbs K2O/ acre to apply)|
|Maintenance range (grain crops)||Yield × Nutrient Removal|
|Maintenance range (forage crops)||(Yield × Nutrient Removal) - [(Yield × Nutrient Removal) x (STK – CL)/50]|
|Build-Up range||(Yield × Nutrient Removal) + [(CL – STK) × (1 + (0.05 x CEC))]|
For corn, Ohio uses the Corn Nitrogen Rate Calculator based at Iowa State University. A significant amount of Ohio farm trial work went into the Iowa recommendations. The rates are based on an economic model and vary with corn and nitrogen prices, as shown in Table 4 below.
|Price of Nitrogen Fertilizer ($/ lb)|
|Price/ bushel corn||$0.30||$0.35||$0.40||$0.45||$0.50|
Recommendations for wheat, a winter crop, are based on the yield goal; in the winter season, dramatic mineralization of organic matter is not expected, and thus does not supply much nitrogen.These recommendations are shown in Table 5 and in the Tri-State Fertilizer Recommendations.
|Wheat Yield Potential (bu/ac)||Nitrogen rate (lb/ac)|
Nitrogen recommendations for other small grains in Ohio follow the wheat model and are based on yield goal. Recommendations are shown in Table 6 and are in the Ohio Agronomy Guide, 15th edition.
|Spring application||Feed Barley||55||95||135|
Forage nitrogen needs can vary greatly depending on the amount of legume in the mixture. Yield potential drives those recommendations, which are shown in Table 7 and in the Ohio Agronomy Guide.
|Yield potential, ton/ac|
|Crop, Percent Legume||4||6||8|
|Annual application (lb N/ac*)|
|Tall grass, less than 20% legume||100||140||180|
|Mixed tall grass-legume, 20 to 35% legume||50||90||130|
|Mixed tall-grass legume, greater than 35% legume||0||0||0|
Nitrogen rates for annual forages (Table 8) are determined by yield goal and previous crop; since forages are a summer crop, mineralization of nitrogen will occur, contributing to nitrogen sources.
|Yield goal (tons dry matter/ac)|
|Good legume stand (5 plants/sq ft)||0||0||40|
|Average legume stand (3 pl/sq ft)||0||40||80|
Additional information for forage nitrogen rates can be found in the Ohio Agronomy Guide, 15th edition; Chapter 7, Forage Production and Chapter 9, Pasture and Grazing Management.
Nutrient content of field crops used in Table 1. (Accessed April 6, 2020) Dairy One, Feed Composition Library: dairyone.com/services/forage-laboratory-services/feed-composition-library/
- International Plant Names Index: ipni.net/article/IPNI-3296. IPNI Estimates of Nutrient Uptake and Removal. Updated May 2014. Table 4.5.
- Kentucky: 2020-2021 Lime and Nutrient Recommendations, AGR-1: ca.uky.edu/agcomm/pubs/agr/agr1/agr1.pdf. Drs. Edwin Ritchey and Josh McGrath, University of Kentucky College of Agriculture, Food and Environment. Page 4, Table 5.
- Michigan: Nutrient Recommendations for Field Crops in Michigan: soil.msu.edu/wp-content/uploads/2014/06/MSU-Nutrient-recomdns-field-crops-E-2904.pdf. Darryl Warncke, Jon Dahl and Lee Jacobs; Extension Bulletin E2904, August 2009; Page 8, Table 3.
- Pennsylvania: The Agronomy Guide 2019-2020; PennState Extension. Editors Jessica Williamson, Dwight Lingenfelter. Page 34, Table 1.2-9. extension.psu.edu/the-penn-state-agronomy-guide
- Tri-States (Illinois, Indiana and Pennsylvania): Tri-State Fertilizer Recommendations for Corn, Soybean, Wheat, and Alfalfa (Bulletin 974)
- United States Department of Agriculture: plants.usda.gov/npk/main
Nitrogen rates (Accessed April 6, 2020)
- “New Ohio Recommended Corn Nitrogen Fertilizer Rates.” Authors: Steve Culman, Anthony Fulford, Peter Thomison, Rich Minyo, Eric Richer, CCA, Harold Watters, CPAg/CCA, Greg LaBarge, CPAg/CCA, Joe Nester, Karen Chapman: agcrops.osu.edu/newsletter/corn-newsletter/2018-07/new-ohio-recommended-corn-nitrogen-fertilizer-rates-now-available.
- “Nitrogen Rate Calculator.” Corn Nitrogen Rate Calculator. Iowa State University, 2021. cnrc.agron.iastate.edu.
- Ohio Agronomy Guide, 15th Edition: agcrops.osu.edu/publications/ohio-agronomy-guide-15th-edition-bulletin-472. Editor Laura Lindsey.
- Wheat, Table 6-5
- Other small grains, Table 6-12
- Forage Production (Perennials: Table 7-9) and (Annuals: Table 7-11)
Nutrient content of vegetable crops (accessed April 7, 2020)
- Knotts Handbook for Vegetable Growers: extension.missouri.edu/sare/documents/KnottsHandbook2012.pdf
- New England Vegetable Management Guide: nevegetable.org/cultural-practices/removal-nutrients-soil
- Nutrient Recommendations for Vegetable Crops in Michigan: soils.msu.edu/wp-content/uploads/2014/06/MSU-Nutrient-recomdns-veg-crops-E-2934.pdf
- USDA Crop Nutrient Tool: plants.usda.gov/npk/main
Steve Culman, Associate Professor and State Specialist in Soil Fertility
R. Mark Sulc, Professor and State Specialist in Forages
Laura Lindsey, Associate Professor, Horticulture and Crop Science
The author would like to thank the following for their time and encouragement while reviewing this publication:
Greg LaBarge, Professor and Field Specialist, Agronomic Systems
Lee Beers, Area Leader and Extension Educator, Agriculture and Natural Resources, Trumbull County
Christine Gelley, Extension Educator, Agriculture and Natural Resources, Noble County
Brad Bergefurd, Horticulture Specialist, Agriculture and Natural Resources, South Centers
Visit The Ohio State University Agronomic Crops Network at agcrops.osu.edu/home for additional information on this topic and more.