Concerns over hurting the soil quality when harvesting some crop residues for cellulosic biofuels, instead of leaving the residues on the fields to help the soil quality, might be unfounded. U.S. Department of Agriculture (USDA) research says that soil quality would not decline if post-harvest corn cobs were removed from the field.
“Crop residues have many useful functions when left in the field, [including] protecting against water and wind erosion [and] may contain essential nutrients for crop growth that can be recycled back into the soil,” among others says Agricultural Research Service (ARS) soil scientist Brian Wienhold, who conducted the study. But his work compared runoff rates and sediment loss from no-till corn fields where postharvest crop residues were either removed or retained and found no significant difference between fields’ sediment loss rates with and without the cobs. The cobs did slightly delay field runoff.
The study concluded that cobs could be removed from other residue and used for bioenergy feedstock without significantly interfering with the role of crop residues in protecting soils. But Wienhold cautions that you need to make sure you balance taking any residue off the fields with the potential benefits and losses it could cause.
Listen to Wienhold’s comments to USDA here: ARS soil scientist Brian Wienhold