The University of Missouri’s College of Agriculture, Food and Natural Resources reported that “strip tillage” is effective in reducing agriculturally-produced nitrous oxide contributions to global warming.
Nitrous oxide (N20), per molecule, contributes about 300 times more climatic warming effect than CO2 (carbon dioxide). It is the third most prevalent contributor to global warming. Applied agricultural nitrogen fertilizer is a chief source of the gas. U.S. farms contribute 58 percent of the global agriculturally-produced nitrous oxide that contributes to warming.
Nitrous oxide emission-reducing strip tillage conceptually incorporates cultivation, fertilization, and planting to minimize unnecessary financial and environmental costs:
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. Additionally, the nitrogen stays deep in the soil, where it less susceptible to environmental loss.
[Plant Science Professor Kelly] Nelson’s research team found that strip tillage with banded nitrogen significantly reduced the amount of greenhouse gases emitted per bushel of corn grain production, when compared to that surface no-till treatments with fertilizer applied on the surface.
Peter Motavalli, associate professor in the MU Department of Soil, Environmental and Atmospheric Sciences, directed the research measuring the soil nitrous oxide emissions.
© 2011 Curators of the University of Missouri, Greater Yields, Fewer Emissions: New farming method reduces nitrous oxide greenhouse gases, University of Missouri College of Argiculture, Food and Natural Resources (10 January 2011)
The study was small and probably imprecise, but it’s likely a good start
Without seeing the actual paper (which apparently has not been published yet), it is difficult to evaluate the soundness of the experimental methods used.
I’m a little leery about our ability to measure and extrapolate nitrous oxide production as compared between strips and whole-field applications, under varying soil and growing season conditions, and fertilizer types.
It stands to reason that confining fertilizer application to plant rows and tilling it in would reduce fertilizer’s overall exposure to the atmosphere.
What happens afterward remains a concern, if the carbon cycle can be used to indicate a comparable complexity in the nitrogen cycle’s relationship to climate warming.