Essential Nutrients Depleted in Crops of Corn, Soybeans, and Wheat Harvested in Ohio

In a collaborative effort involving farmer cooperators, crop consultants, Ohio State University Extension educators, the Ohio Soybean Council, Ohio Corn Checkoff, Ohio Small Grains Checkoff, and the U.S. Department of Agriculture, a significant study has been conducted to provide a robust estimate of grain nutrient removal rates across Ohio.

The research, spanning over 300 on-farm fertilizer trials in 39 Ohio counties, aimed to shed light on the variations in grain nutrient concentrations across corn, soybean, and wheat trials. The average nutrient concentrations for each crop are detailed in Table A1.

The study, which renews the Tri-State fertilizer recommendations first presented by John P. Peters and Howard F. Rhoades in 1995, has revealed some intriguing findings. For instance, the R values in Table A2 are quite low, indicating a poor relationship between grain yield and nutrient concentrations overall. However, the strength of this relationship varied by crop, with soybean generally having a stronger relationship, followed by corn and then wheat.

One of the key observations from the study is that as grain yields increase, nutrient concentrations decrease slightly. This suggests that higher yielding grain contains more starch (or lipids) relative to nutrient. This finding is further reflected in Table A3, which presents the slopes and R values of the regressions between grain nutrient removal rates and grain yield.

The study also reveals that grain nutrient removal rates per bushel of grain have decreased over the past several decades. This decrease in nutrient concentrations, while very subtle, is evident in the slopes reported, which are all small numbers.

Perhaps the most practical implication of this study is that grain yields are a good predictor of nutrient removal rates. As grain yield increased, nutrient removal rates increased as well. This insight could translate into considerable savings in fertilizer costs if farmers adjust their fertilization based on reduced grain nutrient removal rates.

It's important to note that while grain nutrient removal rates provide valuable information about the nutrients leaving a field, they do not offer insights into the total nutrient requirements of a crop. This underscores the need for a comprehensive approach to crop nutrition management.

In conclusion, this collaborative study offers valuable insights into grain nutrient removal rates across Ohio, providing farmers with essential data to make informed decisions about their fertilization practices. The study underscores the importance of considering grain yields when estimating nutrient removal rates and could lead to significant savings in fertilizer costs.

Essential Nutrients Depleted in Crops of Corn, Soybeans, and Wheat Harvested in Ohio