Costs for alternative grain-residue-collection systems

The costs for alternative grain residue collection systems for corn and soybean production in Iowa are examined. All machinery field operations, fuel, other inputs, and labor requirements are identified for the base case with no residue harvest, and for residue harvest by stacks and large round bales, with the owner's equipment and for custom harvest. These five cases are developed for corn and soybeans for conventional and reduced tillage practices. Harvesting alternatives are compared on the basis of costs, fuel input requirements, and gross energy balances of residues collected less energy inputs. The cost of collecting corn and soybean residues varies widely over the collection and tillage systems examined. Other effects constant, the reduced tillage practice leads to a lower cost of harvest than conventional tillage, and stacks are always cheaper than large round bales; however, the former difference is greater than the latter. The dominating effect, in terms of cost of production, is the tillage employed by the producer. Collection of residues yields an energy equivalent 26 times the amount of energy consumed for conventional tillage and 135 times the amount of energy consumed for reduced tillage practices.