Effects of Cover Crops on Soil Health.

Cover crops have been shown to provide many benefits to producers including increased soil carbon, aggregation, fertility, and water infiltration while reducing erosion potential.  Many of these outcomes are linked to the response of soil microbial communities and their activities to longer periods of growing vegetation and increased diversity of plants.  Given conservation program funding for cover crops, producers are eager to measure the tangible benefits of cover crops that offset their cost-share.  In  several different replicated field trials, the following measures were used to detect the influence of cover crops on soil microbial communities and their activities: (i) fungal:bacterial ratios, (ii) in situ N mineralization, (iii) arbuscular mycorrhizal fungi propagule numbers, and (iv) respiratory activities.  All of these approaches indicate a measureable response of soil microorganisms to cover crops.  The remaining question is: which of these measures, or an alternative, would provide the most compelling data to convince a producer to invest in cover crops?