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Agronomic Crops Network

Ohio State University Extension


Updating the Tri-State Fertilizer Recommendations

In 2014, the OSU Soil Fertility Lab ( started work to update the Tri-State Fertilizer Recommendations. These recommendations form the basis of our corn, soybean, wheat and alfalfa nutrient recommendations, but were last updated in 1995. We have partnered with many OSU extension county educators, private crop consultants and individual farmers to run extensive strip trials across the state over the past 4 years. To date, we have over 100 P trials, and nearly 100 K trials that have been conducted in 33 Ohio counties (Figure 1). We have also conducted extensive N rate trials, N timing trials and some trials looking at sulfur needs (not included in map below).

Fig 1. Shaded counties denote where P or K on-farm trials were conducted.

At each site, we’ve collected: 1) soil samples for soil test, 2) leaf tissue concentration at flowering, 3) grain nutrient concentration at harvest, 4) grain yields and 5) management history information. The last of these trials are being harvested now. We are working with Michigan State University and Purdue University with the intention of continuing our recommendations as a 3-state document. Although this is a major undertaking, we hope to have summarized data and new recommendations ready in the summer of 2018. We are genuinely grateful for all the support, commitment and buy-in of the agricultural community in this process and we are looking forward to sharing results with the public in the coming months. This work is being supported by the Ohio Soybean Council and the 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.