By KEVIN WALKER
URBANA, Ill. — Despite the severe drought in this region, corn and soybean grower Jay Johnston had a pretty good year. He said he’s getting yields of 200-plus bushels an acre of corn in some of his fields and yields of up to 60 plus bushels of soybeans, as well; he farms in south-central Illinois.
A couple weeks ago Johnston said he was getting ready to apply fertilizer to his fields. He said it’s usually a combination of potash and anhydrous ammonia.
Johnston uses strip-till and a method called deep banding to apply fertilizer. Deep banding is the placement of fertilizer in the subsoil with strip tillage tools.
Many farmers in the region weren’t as fortunate as Johnston. Fabian Fernandez, an extension agent at the University of Illinois, is advising farmers not to apply fertilizer this year.
“The main thing for nitrogen (N) is there’s a lot of nitrate left in the fields because the plants didn’t use all of the nitrogen applied,” he said. “The problem is a lot of it can leak out in the environment and denitrify. Because of that it’s hard to know how much of that will be available for next year. A lot of that has to do with the winter.”
He went on to say if there’s a rainy spring or warm winter, nitrogen applied in the fall could be lost. “Our recommendation is for farmers to apply less nitrogen now and then some in the spring, or don’t apply any now and apply it all in the spring,” he added.
There are advantages to applying fertilizer in the fall, however; for one, growers have more time in the fall, and second, farmers like to have nitrogen in the soil earlier to give crops an early boost come spring.
“If people decide to apply nitrogen in the fall they should wait until the temperature is 50 degrees and going down,” he advised.
Doing that will minimize the chance that nitrogen will leak out and be lost. Eric Beyers, a site manager for the Farmer’s Independent Research of Seed Technologies testing company, based in Monticello, Ill., agreed many farmers are shifting away from fall applications of N over concerns about product loss.
“But many still use the fall season to apply N because it may offer them a quicker spring planting date – because that process has already been completed,” he said. “Those using fall applications have combined the nitrogen with a stabilizer product that limits its volatilizing or leaching away.”
According to a report by M.L. Vitosh of Michigan State University, loss of anhydrous as a gas when it’s applied to the soil depends on the depth of injection and the soil moisture. Too little moisture will allow the gas to escape into the air, while too much will prevent the sealing of the injection knife opening to the soil surface.
“For very wet soils, application management strategies that minimize N loss include applying the (anhydrous) at least six inches deep and using some type of covering knife apparatus that closes the slot made by the knife,” the report states. “With very dry conditions, deeper applications are generally better.”
Fernandez said another issue worth noting is how to deal with cornstalks and other corn residue this time of year. Recently it’s become popular to apply N to fields in order to help break down the material.
It’s become more of an issue recently, as new corn hybrids have produced stronger stalks. The concept behind adding N is that doing this should increase the nitrogen-to-carbon ratio, which should in turn speed up the degradation process. But a recent study showed adding nitrogen to the field for this purpose doesn’t work; Fernandez said it’s probably because nitrogen is being lost to the environment.