Maximum Return to Nitrogen, or MRTN, is the online nitrogen rate calculator for corn that Land Grant universities across 12 Midwestern states, including Purdue and Michigan State, populate with data.
“I would say that the most notable thing that we keep reinforcing is that the MRTN is actually right,” says University of Illinois ag economist Gary Schnitkey. He helped the Illinois Corn Growers Association initiate a full-scale farm field management study about a decade ago.
“If you apply in the MRTN range, that is the most profitable range, and if you apply above it, you may get a bit higher yield, but you won’t get much higher.”
More importantly, those extra bushels will cost so much more to produce that they won’t pay for the extra nitrogen. You can use the online N-Rate calculator by visiting www.cornnratecalc.org.
There are more than half a million acres enrolled in the Precision Conservation Management Program used to collect the data.
Other takeaways from Schnitkey about the data are that, for cover crops, cereal rye terminated early in front of soybeans makes a lot of sense. And, generally, the most profitable tillage programs are either no-till or one-pass. Using two or more tillage passes burns extra fuel and boosts labor and machinery costs.
Source: NAFB News Service
