From the moment it’s applied, nitrogen is at risk for loss. If not managed properly, up to 30% of nitrogen loss can happen above ground, and up to 70% can be lost below ground, producing serious crop quality (and, therefore, economic) concerns.
By late summer, you should be able to visually identify how your corn crops are taking up nitrogen. Based on a few visual tests, along with soil tests for confirmation, you’ll be able to see how accurate your nitrogen application plan was, how spring and summer weather have impacted nitrogen use thus far, and what you might expect come harvest.
What happens if corn doesn’t have enough nitrogen?
Applied nitrogen can be lost through leaching (the loss of nitrates into the groundwater) and denitrification (the escape of greenhouse gases into the environment). If a plant can’t absorb enough nitrogen through the soil, it will cannibalize its internal sources of nitrogen — draining strength from its stalk and leaves. When that happens, weakened cornstalks, stalk rot and significantly reduced yield can result.
Signs of nitrogen deficiency in corn
Fields at the highest risk of nitrogen loss include fall- and preplant-applied nitrogen fields, those composed of sandy soils and fields with poor drainage. When scouting your fields for signs of nitrogen deficiency, look for the following:
How to address nitrogen loss
Finding a nitrogen deficiency at this point in the season is frustrating, disappointing and can leave you wondering: What do I do now?
“Some may consider a late-season nitrogen application as a rescue. This would only apply to V8 to V12 corn that is waist high to tasseling. But you’re gambling here,” said Scott Pringnitz, Corteva Agriscience market development specialist. “Consider applications at the first sign of loss, soil testing and visual tests. If you see deficiency, then you already have seen yield loss.”
Unfortunately, little can be done if nitrogen deficiencies are found at this time of year. It does, however, provide some key information and learnings so that you can adjust your nitrogen management plan for next year.
If nitrogen deficiencies are found in your fields this summer and fall, here are some tips to consider for next year:
A holistic approach to nutrient management
Realizing maximum yield in the fall not only relies on nitrogen, but also benefits from a holistic approach to nutrient management. This includes making sure phosphorus (P) and potassium (K) levels are adequate to support growth throughout the entire season and protecting nitrogen (N) applications with a nitrogen stabilizer. Remember: Nitrogen remains the staple nutrient required to maximize corn yield.
Soil fertility levels for P and K are affected by:
By supporting your nitrogen applications with a comprehensive approach to nutrient management, you’re covering all your bases when it comes to realizing the yield potential on your cornfields.
Instinct is not registered for sale or use in all states. Contact your state pesticide regulatory agency to determine if a product is registered for sale or use in your state. Federal law does not require any person who applies or supervises the use of Instinct to be certified in accordance with EPA regulations and state, territorial and tribal laws. Some states may have additional requirements related to liquid manure and nitrogen stabilizers. Be sure to consult your state or local Extension service to understand your requirements. When applying Instinct to deep pits, appropriate manure agitation safety steps should be followed. Instinct should be applied directly to the deep pit prior to pumping the pit; a thorough agitation system must be operating in order to evenly distribute Instinct within the deep pit; applicators and handlers of Instinct and manure treated with Instinct are required to use proper protective equipment as stated on the product label; air ventilation systems must be operational inside barns. Do not fall-apply anhydrous ammonia south of Highway 16 in the state of Illinois. Always read and follow label directions.