Washington: Can farmers reduce nitrous oxide, thought to contribute to global warming, and increase crop production simply by adopting a new tillage practice?
Well, researchers at the University of Missouri think it is possible.
Lead researcher Kelly Nelson monitored fields of poorly drained claypan soil that was planted with corn after soybean.
One field was ‘strip tilled’ with nitrogen fertilizer placed in a band in the soil, while another field was left untilled with a surface application of nitrogen fertilizer.
The team found that strip tillage and banded fertilizer significantly reduced the amount of greenhouse gases emitted per bushel of corn grain production, when compared to that of surface applied no-till treatments.
Strip tillage is the practice of tilling a field in strips up to a foot wide and eight to nine inches deep, rather than tilling the entire field, so that crop residues can be left on the surface of most of the field.
By planting corn into those strips, and adding fertilizer during the process, farmers can use less energy, reduce soil erosion and conserve soil moisture in a large area of the field.
“This tells us that more efficient fertilizer use is needed to maintain productivity and profitability,” said Nelson.
“We saw grain yields increase, and this is important when it comes to nitrous oxide emissions and the amount of food produced,” he added.
The research was conducted during above average rainfall growing seasons from 2008 to 2010 in poorly-drained soils so the results of between 2.4 to 3.8 percent cumulative loss of the applied fertilizer N as nitrous oxide N are probably relatively high for conditions in Missouri.
“The main goal for our team has been to identify agricultural practices that maintain or increase production while reducing the environmental impact,” said Peter Motavalli, associate professor in the MU Department of Soil, Environmental and Atmospheric Sciences.
The study was presented at the national meetings of the American Society of Agronomy in November and at the Missouri Crop Management Conference in December.