When Jeff Moyer, farm manager of the Rodale Institute, started cutting back on tillage out of concern for the long-term health of the soil on the institute’s 330-acre research farm in southeast Pennsylvania, he faced a predictable result.
Weeds – and lots of them.
“Year after year, our weed pressure was building until it was just about unmanageable,” said Moyer, in a presentation at Ag Days last week.
As an organic farmer, he couldn’t reach for a jug of Roundup to solve his problems.
“It wasn’t until we came to the conclusion that what we had to do was change the way we manage cover crops that we began to be able to manage weeds,” he said.
That, he says, is the key to reducing tillage under a non-chemically dependent farm production system.
Cover crops also have the added benefit of cycling nitrogen for successive crops, especially when legumes are used.
DON’T BUY IT, GROW IT
With an average frost-free growing season in his area running from May 15-Sept. 15, the Rodale Institute farm hasn’t bought nitrogen for 30 years. It helps that some legumes, such as hairy vetch, are able to overwinter in their mild climate.
“We don’t buy it. We don’t need it. We can grow all the nitrogen we need for our crop rotations,” he said, adding that a single growing season can put 200 pounds of N into the weathered shale forest loam of their farm.
In the off-season, when neighbouring farms are host to brown, dead stubble, the Rodale farm tries to squeeze extra , short-season cover crops into narrow windows in the growing season.
He noted that Bob Rodale, one of the farm’s founders, recognized that soil is a biological system.
“We treat it with chemicals, but it’s really a living, breathing biological organism in there all based on a