Do your corn fields yield less than 170 bu/ac?
If so, you have to be careful when removing corn residue from those fields because you could be depleting the field’s soil organic matter.
That was the message USDA research agronomist Shannon Osbourne shared with those attending the recent Southwest Agricultural Conference at the University of Guelph’s Ridgetown Campus.
Osbourne, based in Brookings, South Dakota, has been studying U.S. Corn Belt residue removal rates since 2000. On this episode of RealAgriculture Corn School, she explains her research and how it indicates that removing residue on fields with long-term yields of less that 170 bu/ac can have a negative impact on soil organic carbon levels. If yields are above 170 bushels, removing residue is “not going to have much of an impact,” says Osbourne who notes that her conclusion is based on research in her region.
For farmers who remove residue for livestock feed sources, bedding or other income opportunities, Osbourne says they should consider planting a cover crop to help maintain soil heath. It will keep the soil covered, add biomass and provide living roots for soil organisms.
Osbourne started adding cover crops to her corn/soy rotation research plots in 2005. Based on her experience, the best results have come from interseeding the crop, “but you have to be careful in the cover crops you choose and the seeding rate so it doesn’t impact the crop itself or harvest.”
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