Results of a three-year soil health study focusing on arbuscular mycorrhizal (AM) fungi proves there is still much to learn about soil microbes.
“This is the purpose of research,” explains Mike Lehman, Soil Microbiologist for the U.S. Department of Agriculture-Agriculture Research Station (USDA-ARS) in Brookings, S.D.
The study focused on answering two questions.
1. Would extending the amount of time plants were growing in the soil, through cover crops, increase AM fungal numbers, biomass, or root colonization?
2. If there is an increased amount of AM present on corn roots (in other words, increased root colonization), will this lead to bigger plants with greater nutrient content, and increased yields?
So, what are the answers based on research? Yes and no.
“We learned cover crops can increase the numbers of native AM in the soil. But (the data also showed) we should not expect this increase to translate into an observable positive impact on the crop within one season,” Lehman explains.