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Agronomic Crops Network

Ohio State University Extension


Growers and Retailers Needed: Understanding Yield Response to K Applications in Ohio

Potassium (K) is a key nutrient for growing profitable crops in Ohio.  Recently in Ohio, consultants, retailers, and farmers have been concerned that soil K values have been decreasing.  One cause for this decrease is higher soybean and corn yields leading to higher K removal rates in grain harvested from Ohio fields.   Further, moving to annual applications of P and K for corn-soybean rotations has been the trend over the past decade.  In recent years, certain regions in Ohio have noted corn and soybean yield responses to K that seem to fall outside the Tri-State Recommendations.

To further investigate the specific conditions and yield response to K, the Ohio AgriBusiness Association, the 4R Nutrient Council, and The Ohio State University have partnered to initiate a new project looking K management across Ohio. In 2023, a pilot study conducted with four, Nutrient Service Providers (NSPs) and support from Ohio Corn and Wheat and Ohio Soybean Council.  Results and discussion from the pilot study has prompted a larger, 4-year study investigating crop yield response to K applications in corn-soybean rotations. 

Consequently, we are looking for growers and Nutrient Service Providers interested in participating in this four-year K project.  Farmers and their consultant would identify fields for the project.  The research team would then work with them to block out replicated K treated and untreated areas.  Fields need to be in a corn and soybean rotation and have pH levels within acceptable range.  Fields would be committed for 4 years.  The farmer would need a yield monitor with GPS to document yield within field plots.  The Ohio State University will work with the farmer or consultant to collect needed soil and crop samples each year. 

If interested, please reach out to Aaron Heilers ( or John Fulton ( 

Additional Guest Authors: Aaron Heilers


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.