Lengthen your Grazing Window - Plant a Cover Crop
By Jared Goplen, Extension Educator
There has been a lot of interest recently about incorporating cover crops into Minnesota cropping systems. While there are a number of environmental benefits that can be associated with using cover crops, it is often difficult to assess how they affect a farm's bottom line. One way cover crops can add value is through extending the grazing window for cattle producers. There are a number of cover crops that are well-suited for livestock grazing, including small grains, legumes, and brassica species that can extend the grazing season into the fall, winter, and early spring. The specific cover crops seeded should be chosen based on the desired grazing window and forage characteristics. Seeding rye or triticale following corn silage harvest is the ideal scenario for many cattle producers to extend the grazing season as it allows plenty of time for establishment before the first freeze while providing protection from soil erosion. It also provides a versatile grazing window since it can be grazed in the fall, winter, or spring. Rye and triticale can put on substantial biomass in the fall, and grow rapidly in the spring as soon as temperatures get above freezing, often accumulating up to one foot of spring growth by mid- to late-April.
Grazed cover crops can provide additional value to land in row-crop production. Rye or triticale can be seeded for $30 - $50 ac-1 depending on seed cost and availability of seeding equipment, and can provide up to 2.5 tons of dry matter ac-1 for spring grazing. Recent years have allowed farmers using this practice to begin grazing spring growth by mid-April through May. Planting soybeans in mid- to late-May allows over one month of spring grazing with less than a 10% loss in soybean yield potential, equating to approximately $40 ac-1. The total cost for seeding a cover crop and accounting for any potential yield loss will likely cost $70 - $90 ac-1, which is similar in cost to keeping a single dry cow in the feed lot for 1 - 1.5 months. One acre of cover crop will likely support 2-3 cows for one month, meaning there is $50 - $130 ac-1 in potential net return that can be gained by planting and grazing a cover crop. Manure hauling costs can also be reduced since cows spend less time in the feed lot. Cows calving in the spring will likely have less disease pressure since they can calve on the cover crop rather than in a feed lot. Permanent pastures will also benefit since the cover crop-grazing period allows additional recovery time for permanent pastures.
There are a number of difficulties that may be encountered when growing and grazing cover crops, despite the economic, agronomic, and environmental benefits that can be gleaned from growing them. Cover crop establishment may suffer if fall precipitation is limited. A harsh winter can result in winterkill of the cover crop. Hoof traffic from spring grazing can increase soil compaction. Cover crops or grazing may not be compatible with a farm’s herbicide-program due to carryover or restricted grazing intervals. Cover crops may also increase pest and diseases pressure for commodity crops grown following the cover crop.
Results from grazing cover crops will vary widely depending on the farm, production goals and what a farmer would like to gain from growing a cover crop. Utilizing cover crops to lengthen the grazing season and provide additional forage is one way to make the short-term economics of growing cover crops more attractive. If interested in growing cover crops, whether or not you want to graze them or not, the best advice is to start small and experiment with what works for you and your farming operation. If you don’t have livestock but would still like to benefit from grazing cover crops, the Minnesota Department of Agriculture has developed a Grazing Exchange website to help connect farmers growing cover crops with livestock producers looking for additional forage to harvest or graze. Utilizing the grazing exchange program provides a way for livestock producers to gain additional forage and provides crop farmers a way to earn additional income from growing cover crops. For more information and questions on growing and grazing cover crops, visit the UMN Extension website.
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