Ongoing field trials since 2002 by a team that includes 16 farmers, Cornell researchers and Cornell Cooperative Extension field crops educators in 10 counties are showing the value of on-farm research. Their results are successfully quantifying and predicting the nitrogen needs for growing corn, saving farmers money and reducing environmental impact.
"With this program, we focus on determining under what situations extra nitrogen would be good to add and when a farmer can save money by reducing fertilizer applications without impacting yield and quality," says Quirine Ketterings, associate professor of crop and soil sciences, who co-leads the research team. "This is the best way to minimize the potential negative environmental and economic impacts of excess nitrogen fertilizer use."
The project evaluated five treatments when growing corn: no starter fertilizer and no additional nitrogen; a starter of 30 lbs nitrogen only; and starter of 30 lbs nitrogen plus 50, 100 of 150 lbs of added nitrogen on corn newly planted in fields that grew alfalfa (a legume), grass or an alfalfa/grass mix the year before.
None of the 16 first-year corn trials evaluated in 2005-06 responded to additional nitrogen after the starter fertilizer, said Cornell graduate student Joseph Lawrence. This indicates that the forage grass and/or legume gave enough nitrogen back to the soil to feed the following year's corn crop, he said. Forage quality was not negatively impacted either.
For example, after farmer Mike Kiechle of Garden of Eden Farm in Philadelphia, N.Y., cut the excess nitrogen in his applications in the 2005 research trial that evaluated all treatments at his farm. With excess nitrogen, the corn grew taller but the ears were smaller and produced less grain.
"The corn that received less nitrogen was shorter, sturdier and produced more corn in the silage," Kiechle said. "I had been happy to harvest 18 tons of corn silage on my clay s
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