Location: Soil Dynamics ResearchTitle: Innovative method for cover crop termination using engine exhaust heat
Submitted to: European Agrophysical Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2018
Publication Date: 12/30/2018
Citation: Kornecki, T.S., Prior, S.A., Runion, G.B. 2018. Innovative method for cover crop termination using engine exhaust heat. European Agrophysical Journal. 5(4):145-156.
Interpretive Summary: The use of cover crops in no-till organic farm systems is increasing. A device was made for a walk-behind tractor powered by a single cylinder gasoline engine to kill a cover crop. This work evaluated the use of heat from engine exhaust (~399 deg. F) and electric heat strips (~860 deg. F) powered by an on-board generator to terminate a cover crop. The device pushes over the cover crop allowing for heat to damage flattened plants. Findings showed that engine generated heat is a viable means of killing cover crops without herbicides, and that cover crop residue can help conserve soil water resources.
Technical Abstract: In the Southern United States, the recommended time to plant cash crops into residue cover is typically three weeks after cover crop termination when the termination rate exceeds 90%; this minimizes resource competition between cover and cash crops. Thus, proper management of cover crop residues is the key to achieving effective no-till planting of cash crops into residue cover without interfering with planting operations. There are different cover crops management methods. One is mechanical termination utilizing a rolling/crimping technique to injure the plant with the crimping bars without cutting stems. Another method is to injure (desiccate) plants using a heat source. To evaluate this concept for terminating cover crops at a small farm scale, a mechanical pusher using exhaust heat from the internal combustion gasoline engine with supplemental heat from heater strips was developed to terminate cover crops. The prototype was developed for a walk-behind tractor powered by a single cylinder gasoline engine. Heat to damage plant tissue was directed from the exhaust manifold to a rectangular perforated delivery steel tube that was in continuous contact with the cover crop that had been flattened by the pusher. In addition, a generator powered by the tractor’s PTO provided electrical energy for three parallel supplemental heater strips. Results demonstrated that using exhaust heat (otherwise lost to the environment) is a viable option to manage cover crops.