Leaching Keeps You From Reaching Goals
Nitrogen management is a complex issue because many different factors affect the overall nitrogen availability to crops. Here are some key agronomic principals behind nitrogen management and a few ways in which you can maximize your nitrogen investment.
Nitrogen is absorbed in one of two forms
Part of the reason nitrogen management can be so complex is because it can appear in different forms in the soil. Nitrogen can only be taken up by the plant in either the nitrate or ammonium forms. Most soils are naturally negatively charged and therefore can only hold positively charged nutrients. Nitrogen in the ammonium form is positively charged, meaning it can be held by the soil.
Over time, through a process called nitrification, ammonium in the soil will be converted to nitrate, which is negatively charged in the soil. Nitrate, being negatively charged, can be a problem because it is not held by the soil, and therefore can easily leach with water through the soil profile and out the drainage tile.
Timing is critical for conversion to the nitrate form
Because leaching is a possibility, nitrate is generally talked about in negative terms. The key to nitrogen management is to get it in the right form when the plant needs it. If you are truly trying to manage nitrogen, you need to convert as much nitrogen as possible to the nitrate form during the grand growth stage of corn.
Methods for converting nitrogen at the optimal stage
Making enough nitrogen available for the corn plant during the grand growth stage can be a challenge, but there are several different methods that can increase the amount of nitrogen available during this time.
- Side dress or top dress nitrogen. Apply nitrogen closer to when it is actually needed by the plant. Side dressing or top dressing can provide enough time for the nitrogen to convert for it to be efficiently taken up by the plant. It is recommended that these applications be done between V4 and V6 in corn so that the nitrogen has time to move with rain into the ground, and then convert to nitrate to be taken up.
- Stabilize the nitrogen. We often talk about stabilizing fall nitrogen to limit the amount that is lost over the winter, but we can lose just as much with spring applications if the weather does not cooperate with us. If the nitrogen converts to the nitrate before the crop can use it, it can very easily be lost, and it often becomes a race between the nitrate leaching and the growth rate of the plant’s roots. In a wet year like this year, the nitrate generally wins, and ends up reaching the tile lines before the plant has a chance to take it up. Stabilizing nitrogen can help keep it in the ammonium form longer, which greatly reduces leaching. Instead of the roots chasing the nitrogen down to the tile lines, stabilizers can help keep the nitrogen in the root zone longer and increase the chances of seeing a return on the nitrogen that was placed in the field.
Nitrogen management can be complex, but if you try to get as much nitrogen to the plant when it needs it, you have the potential to increase your ROI. Contact a Superior Ag Agronomy Sales Specialist for proven nitrogen stabilizer options that best fit your management practice. Don’t let leaching keep you from reaching your goals.