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Agronomic Crops Network

Ohio State University Extension


Revising Fertilizer Recommendations for Corn, Soybean, and Wheat

Ohio State is in the process of updating the Tri-State Recommendations, looking specifically at N, P and K in corn, soybean and wheat. This is a major undertaking that will require a collective effort from numerous extension personnel, crop consultants and farmer cooperators. We will cast a broad net to collect data from a large number of farms across the state to determine economically-optimum fertilization rates.

Experiments will involve applying fertilizer or no fertilizer to replicated strip plots. If a farmer has grid-sampled and has variable rate capabilities, we can write fertilizer prescriptions to get even more information. Farmers can choose which nutrient they’d like to work with and will have a large degree of flexibility in the plot layout and applied rates. We are ideally looking for farms that capture a diversity of soil types, and are especially interested in fields that test low in P and K. Farmers will be paid for their time and effort, and crop consultants or co-op agronomists can get paid by helping facilitate on-trials on their clients’ fields.

Data to be collected:

Soil samples before planting

Leaf tissue samples for nutrient analysis at early reproductive stage

Grain yields and nutrient analysis of grain at harvest

Short questionnaire about soil management

All lab analyses will be paid for and we will work with you to ensure that you understand your results and implications it has on your farm. Interested cooperators can contact Steve Culman at or go to for more information. This work is being generously funded through farmer check-off dollars (Ohio Soybean Council and Ohio Corn and Small Grains Marketing Programs).

Crop Observation and Recommendation Network

C.O.R.N. Newsletter is a summary of crop observations, related information, and appropriate recommendations for Ohio crop producers and industry. C.O.R.N. Newsletter is produced by the Ohio State University Extension Agronomy Team, state specialists at The Ohio State University and the Ohio Agricultural Research and Development Center (OARDC). C.O.R.N. Newsletter questions are directed to Extension and OARDC state specialists and associates at Ohio State.