Written by Jonathan Eisenthal
Many cover crop events focus, naturally, on the farmer. The April 4 Cover Crop Symposium held in St. Cloud shifted the focus to crop advisory personnel, because, in order to make cover crops a workable solution, crop advisers have to have an interactive relationship with the academic research community to assure that cover cropping systems beneficial to farmers become widely available.
Keynote speaker Prof. Rob Myers recently concluded a stint at the University of Minnesota ag campus as the endowed chair of the Minnesota Institute for Sustainable Agriculture. Meyers conducted cover crop research for the north central zone over the past two growing seasons.
Prof. Myers, an adjunct faculty member with University of Missouri Extension service, spoke about how the agriculture sector can get involved with cover crops and the potential that exists. Co-ops and crop advisers can get involved in termination services, establishments services, selling seed, and numerous other aspects in support of farmers who choose to use cover crops in their rotations. He also laid out the reasons why farmers might find cover crops to be a good addition.
“We had 62 attendees including co-op representatives, seed companies, farmers and staff from several agencies,” said Extension Educator Jill Sackett, the organizer of the event. “The audience was very engaged, interested. They were ready and willing to learn more about it. We did touch base on the potential advantage of including cover crops in an operation.”
Dr. Matt Rourke, University of Wisconsin, spoke about nitrogen credits generated by legume cover crops. Sackett noted that a lot of research already exists about how to grow these crops in Minnesota, it just needs to be adjusted from the use as a forage into the more specialized use as a cover crop. Usually cover crops are seeded more lightly, and the growing season is shorter — 4-6 weeks for a cover crop, compared to 8-10 weeks for a forage.
“The easiest way to incorporate cover crops into an operation would be to get it done mid-August, after a canning crop or a small grain. After red potatoes. After green beans,” said Sackett.
A growing body of research is looking into aerial seeding and other methods for planting a cover crop into a standing crop of corn, usually when it’s between v-4 and v-6.
Seed technology development for corn and soybeans is a part of the cover crop picture, Sackett said. One thing that may influence greater adoption of cover crops with corn and soybean rotations is the increasing parity between full season and shorter season varieties. Even two weeks makes a huge difference in the establishment of a cover crop and its effect on soil biology.
Sackett concluded: “The reason why we feel cover crops have an additional biological benefit is that we know there are specific microbes, bacteria, fungi, nematodes that feed well on corn and soybeans. We know that they are there. We also know that when you extend your rotation in any way, shape or form, you are feeding other things. Even more important, at least as far as nutrient cycling, water retention and soil organic matter are the roots out there until November or even going dormant and then growing again in the Spring. Depending on what you choose for your cover crop. It’s that active growth, active uptake and interaction with the soil microbes that gives a biological benefit to your soil. When you look at the research for no-till or strip-till, doing that together with cover crops provides an even greater benefit.”