Cover crops become focus at U of M Winter Crops Meeting
Written by Jonathan Eisenthal
University of Minnesota Professor M. Scott Wells laid out a good news, bad news situation for Winter Crops Day attendees: The good news is cover crops are performing well in Minnesota. The bad news is farmers aren’t making any money at it.
The topic was very much of interest to the more than two dozen farmers meeting at Winter Crops Day in Rochester earlier this month. The annual event, which is also held in Waseca, is organized by the University of Minnesota and supported by the Minnesota Corn Growers Association (MCGA) to provide the latest in crop and soil science for production agriculture.
Wells’ survey of cover crop research showed there is no one-size-fits-all solution. Instead, the research is leading to more suitable matches of species mixes, planting times and cultivation methods to the topography and soils of Minnesota.
For row crops, Wells said Kura clover has been a perennial cover crop used by farmers that has seen growing success in areas of Wisconsin with enough dairy production to justify Kura’s production as a feed crop. Kura can be planted in inter rows and field margins. Another promising new crop with potential as a perennial cover is an oil seed called Pennycress. Cereal rye is another cover crop that works well in Minnesota, according to Wells.
Overall, Wells said the adoption of cover crops, combined with increased fertilizer efficiency and improved tile management, could cut nitrate levels in water sources by nearly fifty percent.
Building on the cover crops topic, University of Minnesota Extension Crops Educator Liz Stahl took growers through a pragmatic overview of herbicide programs needed to succeed with cover crops in a row crop farm operation. The first rule, she advised, was to use herbicides to the full strength advised on the label—cutting the rate will lead directly to evolutionary selection for herbicide-resistant weeds.
She noted that a growing number of farmers are trying to raise covers that can be grazed, where careful adherence to herbicide (and pesticide) labels are essential. They are legally binding to the farmer and are based on keeping these controls out of the food system. Each control is different, with some having a required waiting period of mere weeks before planting a crop that will be grazed, while others require 18 months or more.
It is also essential to know the action of the herbicide, according to Stahl. While residual herbicides are a key tool in the fight against resistant weeds, some will prevent the proper germination and establishment of cover crops. Again, following the advice on waiting periods is essential, she said.
Held annually, Winter Crops Day is open to the public. In addition to focusing on cover crop management, attendees learned about all aspects of potassium, nutrition in crops and soil test methods. MCGA supports Winter Crops Day as part of its mission to make Minnesota corn farmers the most environmentally responsible and sustainable corn farmers in the nation.
