Cover Crops: Not too soon for your fall plans.
As I travel the state, more farmers including pork producers are telling me “I don’t want to have soil exposed over winter.” Cover crops are becoming an integral part of crop rotations, and are recognized by state and federal agencies as an established and important practice. See, for example, the Illinois NRCS Conservation Practice and Code 590--Nutrient Management. Where soils and application timing of manure are classified as “high risk” for nitrate leaching, the 590 standard puts cover crops on the same footing as some more familiar nitrogen-uptake practices. For certain not-so-uncommon situations, liquid manure is singled out by the standard, specifically: “Fields targeted for manure application after small grain or corn silage harvest that meet the high risk conditions outlined in the Nitrogen Management Guidelines will be planted to a double crop grain, annual forage, or cover crop.”
The Illinois 590 Standard phosphorus index Source Factors for a field receiving manure, surface applied and unincorporated, in late summer or early fall can be reduced from “high risk” to “medium risk” by the use of a cover crop, thus dropping a precious three points from the P-index for the field (see the Excel spreadsheet for the P-index at IL NRCS). The new Illinois EPA regulations for livestock producers (Parts 501 and 502) give some implied credit to the use of cover crops, especially for selecting fields that might be suitable for winter manure application (502.630 c.).
Cover crops can do several things for livestock producers, including reducing nutrient movement off fields where manure is applied, increasing the options for “rescue acreage” for manure application, and taking up fall-applied nitrogen for later release to the next year’s crop. Other goals such as weed control and reducing soil compaction are also worth considering.
Cover crops won’t be planted until a few months from now. But those crops take planning—seed selection and purchase, herbicide selection, what fields are highest priority to receive them, what equipment to use, and any custom services to reserve. Some of those decisions need to be made soon, if you are going to implement cover crops on time, following this season’s row crops.
Are you new to cover crops? Here are a couple of tips from the experts. Start small, keep it simple. Every farming situation is different, and you should customize the use of cover crops for your situation, as you learn. Don’t use one year’s outcome to decide the entire fate of cover crops on your farm. As with any cropping system, there will be good years and not-so-good years.
Use the information resources available. For University of Illinois Extension, contact the Commercial Agriculture Extension Educator closest to you. DeKalb’s Northern Research and Extension Center - Russ Higgins (815) 824-2029; at Monmouth, Angie Peltier (309) 734-5161; for Champaign/Urbana Crop Sciences, call Dennis Bowman at (217) 244-0851; and for southern Illinois (Brownstown), call Robert Bellm at (618)-427-3349. Russ Higgins is the Illinois contact for the Midwest Cover Crops Council, whose website is at www.mccc.msu.edu. The Council includes contributors from state universities in the twelve north central states. Their website has been around for a few years, and has a cover crop selection tool that gives county-specific information. Along with your location, you input your field cash crop, expected plant and harvest dates, soil characteristics, and up to three goals for the cover crop; the selection tool shows feasible options for single cover crop species and some limited mixtures. In my view, this website should be a good resource for a cover-crop novice, because it has some experience-based options with the pros and cons for each cover crop choice. Don’t neglect to ask about cover crops at your local Illinois NRCS office. NRCS has a Cover Crop Economics Decision Support Tool available on-line if you want to explore short- and long-term expected benefits of specific cover crops on your farm’s soils. The tool presents a partial budget analysis showing results of a change in your farm’s practices, i.e. adding the cover crops.
There is a rapidly growing information base on cover crops, along with an increase in interest among Midwestern farmers. It’s safe to say that using cover crops on Illinois farms is no longer a “cutting edge” practice. Quite to the contrary, it is supported well enough that a livestock producer managing row crop acreage anywhere in our state should be able to make good decisions about where to start with cover crops.
Ted Funk, PhD, PE
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