While high nitrogen prices are a common topic in the media, the key management strategies are nothing new. The key is increased nutrient use efficiency, and for most of our region that means reducing the risk of nitrogen loss. There is a wide continuum of nitrogen rates from 1.4 pounds of nitrogen per bushel of corn to 0.7 pounds of nitrogen per bushel of corn, the difference is the efficiency of nitrogen use.
Ways to increase nitrogen use efficiency:
- Using nitrogen stabilizers delays the conversion of nitrogen to forms that can be lost to the environment.
- Avoid preplant applications of nitrogen. The wider the time gap between nitrogen application and crop uptake, increases the chance of nitrogen loss. In some cases, fall applications of nitrogen, commercial or manure, can take place 7-10 months before the nitrogen is taken up by the crop.
Read more about fall applied manure:
- Split applications of nitrogen throughout the growing season brings the application closer to use and reduces the amount of nitrogen subject to loss at any one time. Split applications also allow for rate adjustments based on the growing season.
- Incorporate all forms of nitrogen if possible. Nitrogen left on the soil surface is subject to volatilization though more than one mechanism. These loss mechanisms are in addition to loss mechanisms the nitrogen is subject to in the soil.
Read more about nitrogen loss mechanisms:
- Apply sulfur. While the application of sulfur does not always increase yield, it often maintains yield at a lower nitrogen rate. The application of sulfur can increase the plant’s efficiency to utilize of nitrogen.
- Avoid situations where high C:N crop residues or livestock bedding material might reduce nitrogen availability to the crop.
Read more about nitrogen release from organic residues:
- Plant crops requiring supplemental nitrogen on fields with higher organic matter contents. The mineralization of nitrogen from soil organic matter can provide a significant nitrogen contribution.
Read more about ENR:
- Use soil nitrate and ammonium tests for manured fields and late nitrogen season applications. For manured fields, early spring weather can have a huge impact on nitrogen loss. PSNT testing can help determine supplemental nitrogen rates for manured fields. For late season split application of nitrogen in corn, nitrate and ammonium testing can dial late season application rates based on in season crop observations and realistic potential yield.
Read more about PSNT in manured fields:
Read more on late season commercial nitrogen rate determination:
- Focus on maximum profit rather than maximum yield. Often with high fertilizer prices focusing maximum yield or apply a bit extra nitrogen as a “insurance policy”, can be rather expensive management strategies. The MRTN model can help evaluate your options. This year it is very important to complete a crop budget ahead of the growing season.
Read more on MRTN:
- Tissue tests can monitor nitrogen levels in the plant through the growing season.
Read more about collecting plant tissue samples: