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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Dairy Forage Research » Research » Publications at this Location » Publication #336932

Title: Establishing alfalfa in corn silage

item Grabber, John
item RENZ, MARK - University Of Wisconsin
item Riday, Heathcliffe
item OSTERHOLTZ, WILLIAM - University Of Wisconsin
item LAUER, JOSEPH - University Of Wisconsin
item Vadas, Peter

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 1/3/2017
Publication Date: 1/10/2017
Citation: Grabber, J.H., Renz, M.J., Riday, H., Osterholtz, W.R., Lauer, J.G., Vadas, P.A. 2017. Establishing alfalfa in corn silage. In: Proceedings of 2017 Wisconsin Agribusiness Classic, January 10-12, 2017, Madison, Wisconsin. p. 67.

Interpretive Summary:

Technical Abstract: According to recent agricultural statistics, alfalfa was planted on 0.44 million acres and harvested from 2.2 million acres, and corn silage was planted and harvested from 1.0 million acres per year in Wisconsin. Because both crops are often grown in rotation, alfalfa could be interseeded at corn planting to serve as a dual-purpose crop to provide groundcover during corn silage production and forage during subsequent growing seasons. Unfortunately, this system has been unworkable because competition between the co-planted crops often leads to stand failure of interseeded alfalfa. Recent Wisconsin studies demonstrated that properly timed foliar applications of prohexadione-calcium on appropriate alfalfa varieties increased plant survival of interseeded alfalfa by up to 300%. When successfully established, first-year dry matter yield of interseeded alfalfa was twofold greater than that of conventionally spring-seeded alfalfa. Other studies revealed that interseeded alfalfa reduced fall and spring runoff of water and phosphorus by 60% and soil erosion by 80% compared to cropland containing only corn silage residues and weeds. Once established, alfalfa is known to be highly effective for reducing nitrate leaching into groundwater. Assuming an average establishment success rate of 80%, a 5% reduction in corn silage yield, and a prohexadione application cost of $40 per acre, a preliminary economic analysis suggests alfalfa establishment by interseeding followed by full alfalfa production the following year could improve net returns of producers by about 30% ($130 per acre) compared to alfalfa conventionally spring-seeded after corn silage. These improvements in crop yields and profitability and in soil and water conservation are powerful incentives for continued development of reliable and workable corn-interseeded alfalfa production systems on farms in Wisconsin and other northern states where alfalfa cannot be successfully established in the fall after corn silage harvest.