Ways to protect N
One of the first articles I wrote for Successful Farming magazine almost 28 years ago was about the nitrogen stabilizer N-Serve. It's a product that delays the conversion of nitrogen (N) from the ammonium form to the nitrate form and helps reduce nitrogen loss due to leaching and denitrification. It is primarily used for fall and early-spring applications of anhydrous ammonia.
One reason that story has stuck in my mind is that my predecessor, Chuck Sommers, furnished me a compelling photo to use. It was a picture of a giant N (representing nitrogen) being restrained by ropes so it wouldn't escape.
In simplest terms, when conditions are right for nitrogen loss, N-Serve can help prevent nitrogen from escaping. However, when conditions are not conducive to nitrogen loss, it's not needed and represents an extra expense.
N-Serve was a relatively young product then. But nitrogen was also relatively cheap in those days. (Unfortunately, corn was too.) Many farmers opted to simply apply an extra 30 or 40 pounds of nitrogen rather than buy N-Serve. Economically, that probably worked a lot of the time. Although if conditions are right for loss, the amount of nitrogen lost can be far greater than 30 or 40 pounds per acre.
Further complicating the picture in those days was the fact that nitrogen application rates were significantly higher than they are today even though corn yields have increased a lot. Rates were so high that they undoubtedly masked a lot of nitrogen losses.
Another obvious problem with simply applying extra N is that a lot of it ends up in the groundwater.
N-Serve is just one of a number of products that promises to protect nitrogen after you apply it. Contributing editor Larry Reichenberger and I produced eight pages of information about the various products for this issue.
That sounds like a lot. But in some respects we were barely able to scratch the surface. We included results from some research projects, but only a fraction of the hundreds of projects that have been done.
One of the difficulties in writing about nitrogen is that nitrogen management varies so much from one part of the country to another.The same goes for the products that protect nitrogen.
I'm going to use the rest of this space to tell you how to get some of the material we didn't have room for. I can't include meeting notes or phone interviews, but I can direct you to several very good university papers about nitrogen management.
- Click here to access a University of Kentucky paper entitled "Nitrogen Transformation Inhibitors and Controlled Release Urea."
- Click here for a paper entitled "Nitrogen Application Timing, Forms, and Additives" by University of Minnesota soil scientist Gyles Randall and Iowa State University soil fertility speciaist John Sawyer.
- University of Wisconsin soil scientist Carrie Laboski took a look at the performance and economics of nitrogen additives in a 2005 paper entitled "Does it Pay to Use Nitrification and Urease Inhibitors?" The values for corn and N have changed, but the value of her paper hasn't. It's worth reading. Click here to read it.
- There's a recent publication from the University of Missouri entitled "Best Management Practices for Nitrogen Fertilizer in Missouri."