By Scout Nelson
Nitrogen (N) fertilizer is one of the largest variable costs in winter wheat production. Because fertilizer prices can change quickly, using more nitrogen than the crop needs can reduce farm profits. Better nitrogen management can help growers balance crop yield, grain quality, fertilizer costs, and environmental concerns during the 2027 growing season.
Research by Clarence Winter, SDSU Extension Agronomy Field Specialist along with Christopher Graham, and David Karki examined how winter wheat responds to nitrogen. Their research showed that nitrogen needs can change from one field and year to another, making soil testing and careful planning important tools for growers.
SDSU researchers conducted winter wheat nitrogen trials at Wall and Sturgis during 2023 and 2024. Before planting, researchers measured existing soil nitrogen levels and applied four fertilizer rates of 0, 50, 100, and 150 pounds of nitrogen per acre.
Results showed that nitrogen responses varied significantly between locations and years. At Sturgis in 2023, winter wheat yields reached a maximum of 61 bushels per acre with 135 pounds of total nitrogen per acre, including both soil nitrogen and applied fertilizer. This level generated an economic return of approximately $0.84 per pound of applied nitrogen, based on a wheat price of $6 per bushel.
At Wall in 2023, yields reached a maximum of 51 bushels per acre with 115 pounds of total nitrogen per acre. Researchers estimated a return of roughly $1 per pound of nitrogen, demonstrating positive economic benefits from fertilizer application under those growing conditions.
However, conditions differed substantially in 2024. At the Sturgis location, researchers observed no yield response from additional nitrogen applications. Findings suggested that residual soil nitrogen supplied enough nutrients to satisfy crop demand throughout the season.
The research highlighted two important scenarios for growers. In some years, crops respond strongly to applied nitrogen and produce economic returns. In other years, soil nutrients and favorable weather conditions meet crop needs without additional fertilizer. Because of this variability, relying on flat-rate nitrogen applications can increase the risk of unnecessary expenses and lower profitability.
Nitrogen recovery rates in responsive years averaged only 30% to 40%. Similar studies conducted by USDA-ARS and regional universities have shown that cereals often recover less than half of the nitrogen applied. With nitrogen fertilizer ranging from approximately $0.70 to $0.80 per pound, low efficiency can make achieving a positive return on investment more difficult.
Another strategy that improves nitrogen use efficiency is split nitrogen application. This practice involves applying a portion of the fertilizer at planting and applying the remainder later in the season when crop demand increases. Split applications help avoid excessive fall growth while ensuring nutrients remain available during spring growth periods.
This practice can also provide economic flexibility. For example, a smaller nitrogen application can be made at planting when crop demand is relatively low. If weather conditions remain favorable and nitrogen prices become more manageable later in the season, a second application can be made to support higher yield potential. This strategy can improve both return on investment and fertilizer efficiency.
Grain protein content remains another important factor for wheat producers. Most grain elevators require a minimum protein level of 12% for winter wheat. Wheat that falls below this level may receive price discounts, while grain exceeding 12% protein may qualify for market premiums.
Data collected across Vivian, Wall, and Sturgis over 14 site-years showed that increased nitrogen availability generally improved grain protein content. Analysis indicated that 76 pounds of total nitrogen per acre provided a 25% chance of achieving 12% protein, while 111 pounds of total nitrogen per acre increased the likelihood to 50%.
The economic outlook for the 2027 growing season remains challenging because of low commodity prices and high production costs. While growers cannot control fertilizer or grain markets, they can influence how efficiently nitrogen is used on their farms.
Photo Credit: gettyimages-dleonis
Categories: South Dakota, Crops, Wheat