Something for Your Toolbox – Cover Crops and Tillage

The question of cover crops is becoming more and more of a topic in Minnesota commodity groups, special interest groups, environmental groups and the Minnesota Department of Agriculture. Last week, University of Minnesota Extension held a Cover Crops workshop in a Corn/Soybean Rotation Field Day in Okabena, Minn., addressing exactly that topic.

With harvest and fall field work winding down and a cooler than normal fall day, the crowd packed into the American Legion hall was large (unofficial just shy of 170). The Worthington Daily Globe happened to be there and followed up with an article about Ray Archuleta and his philosophy on tillage

While there was nothing incorrect about the article and the writer correctly quoted Archuleta, I was also at the meeting and my personal impression of Mr. Archuleta was that he was a cheer leader for farming like nature but was not necessarily up to speed in his talk for Minnesota agriculture.

Dr. Paul Meints

Dr. Paul Meints

Much of what he said concerning tillage damaging soil structure is true and documented in the literature, however his approach may not take enough into consideration heavy residue from typical corn yields, etc., in the upper  Midwest.

UMN research and extension, as well as the USDA scientist from South Dakota who also spoke at the Okabena meeting indicated that every tillage pass disrupts soil structure; however we still do not have an absolute alternative to cease all tillage in Minnesota and retain economic production.

There is however, current scientific research looking into ideas and options. A recent article by Frank Lessiter in No Till Farmer Magazine cites research by Dr. Dave Franzen, NDSU Soil Extension Specialist, reporting continuous no-till for more than six years in corn can allow for reduced nitrogen input by 40-50 pounds per year without profit loss in North Dakota. This is pretty exciting science demonstrating the potential for northern production regions and finding viable options outside the traditional box in our farming systems.  

Mr. Archuleta lives in North Carolina where winter temps are low enough that plant residue is consumed by microbes much faster than it is in Minnesota with our long winter. His own talk referenced soils in NC where the organic matter content was naturally around 1 percent in coarse textured soils and up to near 5 percent in the grassland regions.

He stated that with intensive cover crop systems they had built OM up to 6 percent. He also mentioned that this was above the percentage it was when the land was first farmed. In that argument, farming like nature is not what he is advocating for North Carolina, either. He also strongly argued for all land to return to grazing within a row crop system without looking at the practicality for both the livestock industry and the typical Minnesota farm.

The MSR&PC Production Action Team has cover crops as an upper priority component in our current Request for Proposals (RFP) to stay ahead of the curve on what does and what does not currently work in Minnesota.

Are cover crops a good idea? Yes, but we are nowhere near the understanding needed to have widespread implementation in the state.

Cover crops work well in regions of the U.S. where the winter comes later than here but the same crops and technology do not readily adapt to our system. Cover crops can hold the soil against erosion, tie up nutrients to be retained on the farm rather than lost from the field, improve soil health and structure. Again, we don’t have a workable system here yet. Thus the common theme is expect failure while initiating this into a cropping system presented by Mr. Archuleta and others who shared at the meeting. We should develop a workable approach with sound science and viable economics in this as in all things we do for Minnesota soybean farmers.

In short, Mr. Archuleta gave an enthusiastic talk, but my impression of the crowd reception was that they listened, but also retained a healthy skepticism. His talk utilized the broad brush strokes employed to present a solid concept but did not offer direct implementation solutions for Minnesota farmers.

The MSR&PC through the Production Action Team currently funds a joint project with Jodi DeJong-Hughes, Phil Glogoza, and Dean Malvick (UMN) and Aaron Daigh and Abbey Wick (NDSU) titled “Maximizing soil warming and soil health under different tillage practices in a corn-soybean rotation.” This research and other work coupled with Dr. Franzen’s study noted above will help northern farmers understand how we can adjust our farming practice while remaining economically viable.

Minnesota soybean farmer’s willingness to invest check off funds to increase understanding of optimum land management for soil health, productivity and farm profitability will continue. In addition, the Production Action Team 2015 RFP includes a query for research into cover crops and related technology practical for Minnesota agriculture. It is the commitment of the Production Action Team to fund research that will lead to sound practical and financially viable options for Minnesota farmers in the areas of cover crops and tillage options for the various soils and cropping systems throughout the state.

 Dr. Paul Meints is the Director of Research at Minnesota Soybean and has an MS in plant breeding and genetics and a PhD in Seed Physiology. Email him at paul@mnsoybean.com.