A study by scientists with the U.S. Department of Agriculture indicated soil quality would not decline if post-harvest corncob residue was removed from fields as a potential biofuel source.
"We didn't have data on how post-harvest cob residues might protect soil quality," USDA soil scientist Brian Weinhold said, "But corncobs make up 20 percent of residue by weight, which means that the average U.S. production of corn could provide 40 [million] to 50 million tons of cobs for feedstock every year."
The department's Agroecosystem Management Research Unit in Lincoln, Neb., led studies that compared runoff rates and sediment loss during post-harvest rainfall from cornfields where crop residues were either removed or retained.
The presence or absence of corn cobs on test plots did not significantly affect sediment loss rates during the rainfall events, the researchers said.
The results indicated cobs could be removed from other residue and used for bioenergy feedstock without significantly interfering with the role of crop residues in protecting soils, Wienhold said.