Note to readers, attached is the complete final report for FNE97-179
Tony Potenza is an organic grower of soya, corn, and other grains. Heretofore he has seeded rye as a cover crop following his soya harvest, but he has not been able to obtain an adequate cover this way. His SARE project concerned 1) experimentation with several grass and legume species as cover crops, 2) earlier sowing to permit better stand establishment of the cover, and 3) modification of cultivation equipment to permit sowing of the cover crop between the rows of standing soya, prior to the soya harvest.
In preliminary trials he and his friend John Myers, who is also an organic grain grower, experimented with several species that they considered likely candidates for cover crops. They settled on four—Dutch white clover, medium red clover, annual ryegrass, and creeping red fescue—for further investigation. In order to sow the cover crops while the soya was still standing, they modified Danish shank row-crop cultivators to perform the task of sowing simultaneously with the last cultivation of the soya in mid-July. The modifications consisted of mounting Gandy seed boxes on the cultivators, and running tubes, through which the seeds drop, from the Gandy boxes to just behind the shanks. Mr. Myers mounted an electric motor on his cultivator to power the seed box; Mr. Potenza powered his with a drive wheel.
Mr. Potenza reports that their system worked well for Dutch white clover, medium red clover, and annual ryegrass. All established well between the rows of soya, but did not grow so much as to interfere with the operation of the combine, when it came time to harvest the soya. Ground cover through the winter was good, and by planting time the following spring enough biomass had accumulated that Mr. Myers was able to graze cattle on it. Of the various cover crops tried, Mr. Myers prefers ryegrass because it establishes well, the seed is cheap, and it provides plenty of biomass for spring grazing. Mr. Potenza prefers a mixture of ryegrass and Dutch white clover, because the clover fixes atmospheric nitrogen, and the ryegrass establishes well in wet spots where the clover does not easily take root.
Mr. Potenza followed his cover trials with corn. He reports an 8% increase in corn yields following legume winter cover crops, which translated into a net increase in profit of about $15 per acre, with little additional investment or labor, apart from the initial modifications done to the cultivator. Mr. Potenza estimates the cost of the modifications at $600 to $900.