ARS | Publication request: Cover cropping to enhance arbuscular mycorrhizal fungi in diversified crop rotations of the upper midwest U.S. corn belt

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 29, 2011
Publication Date: May 24, 2011
Citation: Lehman, R.M., Taheri, W.I., Buyer, J.S., Osborne, S.L. 2011. Cover cropping to enhance arbuscular mycorrhizal fungi in diversified crop rotations of the upper midwest U.S. corn belt. Soil Ecology Society, Kelowna, British Colombia, Canada.

Technical Abstract: Intensive agricultural practices, such as tillage, monocropping, seasonal fallow periods, and inorganic nutrient application, have been shown to reduce arbuscular mycorrrhizal fungi (AMF). Agricultural practices that reduce AMF may reduce the benefits provided to crops by AMF, such as nutrient acquisition and disease resistance, which costs producers who must pay for these services. Utilizing no-till agricultural production systems with greater crop diversity (such as wheat-corn-soybean compared to corn-soybean or continuous corn), we are evaluating the influence of different cover crops on the number of soil AMF propagules, their colonization of corn roots, and their relationship with P uptake in corn. At both a research farm and a producer’s farm, we have established replicated, no-till plots with cover crops seeded after wheat harvest and then burned down prior to corn seeding the following year. As determined by the most-probable-number technique using Bahai grass as a host, soil AMF propagule numbers were increased with forage oats as a cover crop in all three site-years sampled to date. The MPN data was corroborated by analysis of the neutral lipid fatty acid mycorrhizal biomarker, C16:1cis11. Identification of specific cover crops that promote AMF for inclusion in diversified, no till cropping rotations in the upper Midwest U.S. will provide opportunity for reduced inorganic nutrient application with economic and environmental benefit.