By: Rebecca Konopka
Carter County Extension Agent
Nitrogen fertilizer is one of the most critical inputs for crop and forage production, but high prices and potential supply delays mean farmers need to be strategic to ensure every pound applied provides the greatest return.
Start with a soil test. Even though soil tests do not directly measure nitrogen, they are still the foundation of sound nitrogen management. Soil test results provide recommendations for lime, phosphorus (P) and potassium (K), which influence how efficiently crops use nitrogen, as fields with low soil pH or other nutrient deficiencies often respond poorly to nitrogen applications. Additional nitrogen will not overcome other nutrient limitations. Bringing soil pH and other nutrients into the recommended range allows plants to use applied nitrogen more efficiently, saving money.
Follow university recommendations for nitrogen rates. With higher nitrogen prices, applying more than recommended is a costly practice that rarely pays off. UK Extension fertilizer recommendations are based on years of field research across the state and are designed to match nitrogen rates with crop needs under Kentucky conditions. For many crops, especially corn, nitrogen recommendations are provided as a range, and moving toward the lower end can make economic sense — particularly when paired with practices that improve nitrogen efficiency.
Improve nitrogen use efficiency through timing. Nitrogen is most vulnerable to loss when it is applied too early or long before crop uptake. Rainfall and warm temperatures can lead to leaching, runoff or denitrification, reducing the amount of nitrogen available to the crop.
To reduce losses, farmers should consider applying nitrogen closer to when crops need it, splitting nitrogen applications on corn and avoiding fall nitrogen applications for spring-planted crops.
Nitrogen stabilizers and placement can reduce losses. Urease inhibitors can reduce volatilization losses of surface-applied urea-containing fertilizers. Nitrogen placement below residue or soil surface can also reduce nitrogen losses by limiting contact with residue, decreasing immobilization and reducing urea volatilization.
Consider alternative nitrogen materials. Animal manures — such as poultry litter or livestock manure composts — can supply meaningful amounts of nitrogen while also providing other nutrients and organic matter. When using manure, it is important to test the material to determine nutrient content, credit manure-supplied nitrogen toward total crop needs and apply at rates that align with crop demand. Manure is not “free fertilizer,” but when properly managed, it can reduce the need for purchased nitrogen products. Make sure that animal manures are appropriately priced relative to commercial fertilizer, accounting for the value of nitrogen, phosphorus and potassium supplied.
Think about cropping systems and forages. Forage systems and crop rotations can also influence nitrogen needs. Forages containing legumes can supply much of their own nitrogen, reducing or eliminating the need for purchased nitrogen fertilizer. Similarly, crops like soybeans do not require nitrogen fertilizer, while crops such as corn have much higher nitrogen demands. In a year with high nitrogen prices, understanding these differences is critical when planning rotations or forage management strategies.
Nitrogen management decisions carry more risk in years of high prices and limited supply. Contact your Carter County Extension office for help with soil testing, selecting appropriate nitrogen rates and timing, evaluating alternative nutrient sources and adjusting fertility plans to current economic conditions. Educational programs of the Cooperative Extension Service serve all people regardless of economic or social status and will not discriminate on the basis of race, color, ethnic origin, national origin, creed, religion, political belief, sex, sexual orientation, gender identity, gender expressions, pregnancy, marital status, genetic information, age, veteran status, or physical or mental disability.
Upcoming Events:
- Fencing School – April 28 in Mason County
- Understanding Seed Packets & Beginning Gardening – April 29 @ Noon
- UK North Farm Forage Variety Trail Tour – May 1
- Little Sandy Beekeepers – May 5 @ 6:30 – Speaker: Dr. Amanda Skidmore, State Apiarist
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