Submitted to: Forage Focus
Publication Type: Popular Publication
Publication Acceptance Date: August 4, 2009
Publication Date: August 24, 2009
Citation: Jokela, W.E. 2009. Cover Crops Can Improve Soil Quality Under No-till Corn Silage. Forage Focus Magazine, Midwest Forage Association, St. Paul, Minnesota. August 2009 Issue. p. 21.
Continuous corn silage production, even with no-till, can degrade soil quality because of nutrient depletion and minimal organic matter (OM) additions. This can reduce productivity and worsen environmental problems such as nutrient runoff and soil erosion. A study was conducted to evaluate effects of cover or companion crops, and/or low-solids liquid dairy manure on soil properties in a no-till corn silage system. Cropping treatments included corn grown 1) with a living mulch of Kura clover or 2) June-interseeded red clover, both followed by one year of clover forage production; and continuous corn grown with 3) June inter-seeded Italian ryegrass, 4) September-seeded winter rye, or 5) no cover crop. Liquid dairy manure was surface-applied annually in April to all treatments except 6) an additional no-cover treatment receiving only N. In this no-till system, most soil parameters were highest in the surface soil layer and decreased with soil depth. Companion/cover crops led to increased abundance of large water-stable soil aggregates. Microbial biomass and the active carbon fraction of OM were significantly increased by cover crops. Manure application alone showed no improvement in soil quality indicators, presumably because of low-solids content as a result of solids separation. Overall soil quality, as indicated by a soil quality index, was improved by the use of cover crops in manured corn silage.