Military actions against Iran commenced on February 28, 2026. This has led to the closure of the Strait of Hormuz, a narrow shipping channel through which roughly 25% of the globally traded nitrogen passes (Quinn, 2026). Farmers who have not already purchased their nitrogen supplies will be forced to do business in a market with increased volatility and elevated prices as planting season rapidly approaches. This uncertainty should force those producers to revisit their planting intentions or nitrogen management strategy.
Nitrogen prices are up sharply in the two weeks since military action began in the Middle East. Recent figures show that Urea prices are up 20-25% at the port of New Orleans, while 28% UAN is up 15-20%. The national average retail price for nitrogen products, as reported by Progressive Farmer – DTN, are $674/ton for urea and $464/ton for 28% UAN. Traditionally the Ohio Quarterly Fertilizer Price Summary has seen Ohio prices slightly softer than the national average (Bennett et al., 2026). The results for the 2026 second quarter are set to be published mid-April and will provide a glimpse at current market prices in the state.
With some fertilizer prices elevated, growers may need to alter their plans to utilize a more economical approach to nitrogen management. This may include using a different product or adjusting their rate using the Corn Nitrogen Rate Calculator (CNRC), which finds the maximum return to nitrogen (MRTN), which can be accessed at this link: cornnratecalc.org. The MRTN tool utilizes economic data, including the projected new crop corn market price per bushel and nitrogen fertilizer retail prices, which can also be customized to reflect pre-paid nitrogen or current market prices. The tool then utilizes the ratio of nitrogen price to corn price, as well as historical yield response data, to determine at what nitrogen rate the highest returns to nitrogen will be realized, while protecting yield potential. The higher nitrogen prices and low corn prices in current markets show a larger ratio, and the MRTN tool will recommend a reduction in nitrogen rate. A scenario comparing 28% UAN at a price of $400/ton and the same fertilizer at $450/ton is shown below.
When utilizing the CNRC to determine MRTN, be sure to select Ohio (or the state you farm in) to ensure the yield response data aligns with your farm’s location. The default crop rotation is corn following soybean but can be changed to corn following corn. In addition, the CNRC can utilize a single nitrogen price, or multiple if a farm utilizes different forms of nitrogen. For this example, a single price will be utilized. The default values in the calculator reflect current market prices for both the selected nitrogen fertilizer and corn. Figure 1: At a 28% UAN price of $400/ton and a corn price of $4.50/bu, the price ratio is 0.158, the MRTN recommendation is 160 lb N/acre, which will result in a $242.14 per acre net return. At this nitrogen rate, based on 273 sites of Ohio data, the corn crop is expected to reach 96% of the maximum yield potential.
In the second scenario, shown in Figure 2, corn price remains constant at $4.50/bu, while 28% UAN price has increased to $450/ton. In this situation, the price ratio has increased to 0.178, and the suggested MRTN rate has decreased to 152 lb N/ac. At this rate, based on Ohio data, the predicted maximum yield potential is still 96%, and the return over nitrogen is expected to be $228.12 per acre.
In each scenario, there is a blue highlighted window on the graph to the left and right of the recommended MRTN rate. That window can also be found in the chart at the top of each figure and represents the potential nitrogen rates that could be utilized for a return within about $1 of the highest net return to nitrogen. For Figure 1, a producer could apply anywhere from 146-172 lb N/ac and would be within $1 of the net return at the MRTN-calculated rate. For Figure 2, that range would be 139-165 lb N/ac. This allows a producer the freedom to increase nitrogen by a small extent above the MRTN rate if they are nervous about cutting nitrogen rates or allows a producer to reduce nitrogen rates to the lower end to further conserve fertilizer and keep more money in their pocket.
Still curious how well this tool works in the real world? OSU Extension has conducted nitrogen rate trials utilizing this MRTN framework to show how this tool works on the farm. These results can be found in an On-Farm Research Report, linked here, or in the following eFields On-Farm Research Publications: 2023 eFields, pages 86-89 and 2024 eFields, pages 86-87.
References:
Quinn, R. 2026. DTN Retail Fertilizer Trends. DTN Progressive Farmer. https://www.dtnpf.com/agriculture/web/ag/crops/article/2026/03/04/seven-eight-major-fertilizers-higher
Bennett, A., Richer, E., & Schroeder, C, (2026). 2026 First Quarter Fertilizer Prices Across Ohio. Farm Office Blog. https://farmoffice.osu.edu/farm-management/quarterly-fertilizer-price-summary
Cochran, R. 2025. Using the Maximum Return to Nitrogen (MRTN) Framework to Determine Optimum Nitrogen Rate Following a Cereal Rye Cover Crop. Ohio State University Extension On-Farm Research Reports. https://agcrops.osu.edu/sites/agcrops/files /ofr_reports/Cochran_MRTN_Final.pdf