EPHRATA, Pa. — In many parts of Pennsylvania, getting a cover crop seeded after corn or soybeans can be difficult, especially if it gets cold too soon.
And while a cover crop interseeder may provide a way to get seed in when a crop is standing, it’s not a perfect solution.
Greg Roth, professor of agronomy at Penn State, talked about cover crop interseeders Monday during a webinar on cover crop management.
It was the latest in a series of presentations by Northeast SARE (Sustainable Agriculture Research & Education) as part of its Cover Crop Innovations Program, which is aimed at putting in cover crop management practices on an additional 2,500 acres of farmland in the state.
Penn State’s first cover crop interseeder was developed in 2010.
An interseeder allows a grower to plant cover crops in standing corn or soybeans, which is especially helpful in colder areas such as the state’s northern tier, where the time frame between getting a crop off and seeding cover crops is very short.
“Producers have been very reluctant to invest in cover crops in those areas so the interseeder is an option to get it going before the preceding crop comes off,” Roth said.
Seeding cover crops is most effective when corn is between its 6- and 8-leaf stage, when the threat of weeds has largely dissipated, he said.
The interseeder concept has been used extensively in Europe, Canada and the Pacific Northwest.
Penn State’s interseeder is also capable of applying sidedress nitrogen and herbicide at one time to cut down on fuel costs.
“We’re trying to develop a system that would work in our no-till agriculture,” Roth said.
The first interseeder trials were done in 2010.
Roth said he was pleased with the quality of clover planted between corn rows at the Penn State research farm in Rock Springs, Pa., and even found good growth in cover crops the following spring.
Corn was planted in another plot of 4-foot-tall rye cover crop in spring 2011 to find out if the cover crop affected the corn yield.
Roth said the average corn yield with the rye cover crop was 100 bushels per acre, compared with 90 bushels in a plot planted with no cover crops.
“At $7 a bushel for corn, that can be fairly significant,” he said.
Experiments continued in 2012, with one also focusing on interseeding a mixture of rye and clover into soybeans.
Roth said it created a problem with harvesting the soybeans because the mixture became very active and competed with the soybeans for nutrients.
He said he’s looking into doing experiments with a less vigorous clover, such as white clover, as a solution.
On a farm in northeast Pennsylvania, the interseeder produced only mixed results in a cornfield.
Roth said he’s working on developing different seeding techniques to improve consistency. He’s also looking at more varieties of cover crops, including rye, and perhaps bumping up seeding rates to see what impact that has.
Other interseeder prototypes are in the works and with the potential benefits, Roth hopes farmers will get access to them in the next couple of years.
“You can get higher yields in the next year, combine spray and sidedress, reduce nitrogen inputs, and have some fall grazing potential and some wildlife benefits,” he said.
“If you add all these up, the economic potential can be significant.”