Update from the Field: Have We Lost Our Minds or Just Our Nitrogen?
Posted by Dave Dyson, Agronomist on June 25, 2019
The post may reference products and/or services only available to our Retail Farm Center customers. For more information contact your Territory Manager at The Andersons.
As the title suggests, the constant rainy weather the Corn Belt has been experiencing may cause us to lose our minds. Not only that, it can also leave us wondering how much nitrogen is left in the soil for the corn crop. Nitrogen can be one of the most expensive inputs purchased, which is why extra nitrogen is not always considered.
When nitrogen is applied to the soil, microorganisms start converting ammonium nitrogen to nitrate nitrogen. In a wet year, you can lose nitrogen in two different ways as shown in Figure 1. The first way to lose nitrogen is through leaching. This happens more in sandy soil since the excess water in the soil usually moves down and through the soil profile. However, we can still see nitrates leach out of heavier ground through tile. While the water is moving down and through the soil, the positively-charged water can pick up and carry away the negatively-charged nitrate. The second way to lose nitrogen is through denitrification. This happens when water saturates the soil and starts to pond. The excess water can change nitrate into nitrogen gas, which literally “gases off” into the air.
Figure 1: Once nitrogen is applied to the soil, it is at risk to either leaching or denitrification.
Now the question is, “Do I have enough nitrogen to finish my corn crop through grain fill?” The question is a valid one because soil nitrogen in the nitrate form can disappear at rates as high as 5% per day of ponding or saturated soil conditions (Hoeft, Robert. 2004. Predicting and Measuring Nitrogen Loss. Univ. of Illinois "The Bulletin"). Once the nitrogen is converted to nitrate, it can easily be leached out of the soil with water. Loss of nitrate nitrogen through leaching on coarse-textured, sandy soils is also very rapid. Pre-plant or early side-dress applications are at risk. More recent sidedress applications of unprotected nitrate-containing fertilizers (28% or 32%) are at most risk of N loss.
If you are worried about nitrogen loss in your farming operation, we suggest you perform a Pre-Sidedress Nitrate Test or PSNT. This will provide a snapshot of how much nitrogen is in the soil, and if more needs to be applied. This is a great opportunity to learn about the benefits of Y-drops and the advantages of a post application of UAN with Y-drops.
We encourage you to use a nitrogen stabilizer when applying nitrogen. You can increase the nitrogen stability in the soil when you use UltraMate® LQ or UltraMate Zn in conjunction with Y-drops while applying post nitrogen. UltraMate LQ will carbon chelate the nitrogen molecule, protecting it from both leaching and denitrification. If UltraMate Zn is applied, you’ll be adding 1qt/ac of Nulex® 15% Zinc to your cropping system for every gallon used. Contact your local Ag Advisor from The Andersons for more information and recommendations.
Take away bullets:
- Nitrogen can leave the soil by leaching and denitrification
- Use the PSNT to determine how much nitrogen is in the soil
- Learn about the benefits of using Y-drops to post apply nitrogen in corn
- Use UltraMate LQ or Zn as a nitrogen stabilizer when applying nitrogen
Dave Dyson is a regional agronomist for The Andersons’ Farm Centers which are located throughout Ohio, Michigan, and Indiana. He is an Indiana native and grew up on a dairy farm in Miami County. A graduate of Purdue University with a degree in Crop & Soil Science, Dave has a deep knowledge of various agronomic topics and is committed to helping growers improve their crops. If you have any questions, Dave can be reached at david_dyson@andersonsinc.com.
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