Corn nitrogen recommendations in Ohio are generated from an online tool: Maximum Return to N (MRTN). It uses corn yield response to nitrogen along with a farm’s nitrogen cost and corn market price. The web tool calculates the incremental corn yield increase for each unit of N added and then subtracts the cost of N from the return to find the point where the economic return to N application is maximized.
The web tool is found at https://www.cornnratecalc.org/, where new yield response data for Ohio was added in April 2025. The database reflects corn N response trials through 2024. The only input data required is the price of the N source used by the farm in dollars per ton and the market price of corn.
For Ohio, yield response data for two rotations are included: corn following soybeans and corn followed by corn. The database contains trials from a range of growing environments, representing 273 trial sites for soybean following corn and 83 sites for corn following corn. Trial yields range up to 277 bushels per acre.
If you want more details on using the tool, refer to CORN 2022-05 at https://agcrops.osu.edu/newsletter/corn-newsletter/2022-05/using-corn-nitrogen-rate-calculator