Ithaca, New York
June 20, 2007
By Eleanor Jacobs and Kara Lynn
Dunn
Cornell University
ChronicleOnline
Ongoing field trials since 2002 by
a team that includes 16 farmers,
Cornell University
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 soils, so
when we harvested 20 tons in 2006, I was excited." This year,
Kiechle is applying half the nitrogen he used last year. "This
on-farm research trial showed I was just wasting money to apply
more. I cut back, and that has saved me about $10-$12 per acre."
And when farmer Dan Mulvaney used only 30 lbs of starter
nitrogen on second-year corn at his farm in Conesus, N.Y., his
corn silage yields increased 4 to 5 tons per acre, and his
shelled corn increased from 100 to 140 bushels per acre.
In Freeville, N.Y., Beck Farm crop manager Jerry Coller manages
2,000 acres of crops and does not have enough manure to meet the
nitrogen needs of those crops. He says the precision nitrogen
project showed him that his grass crops provide more nitrogen
than he thought, so less manure is required to fertilize those
lands to grow corn. Coller has reconfigured applications to
better distribute the farm's manure resources to other fields.
In New York state, some 460,000 acres produced 8.28 million tons
of silage in 2006. Nitrogen fertilizer is growing increasingly
expensive (about 40 cents per pound last year), so any reduction
in nitrogen use improves farmers' bottom line and prevents
nutrient losses into the environment.
This project, in its final year, is funded with grants from the
Northern New York Agricultural Development Program and New York
Farm Viability Institute and the Cornell Agricultural Research
Station. The project team will also provide conclusions about
use of soil nitrogen tests to determine when corn grown in New
York needs nitrogen.
Eleanor Jacobs and Kara Dunn are both freelance writers. |
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