Analyzing Microbial Functional Diversity Using Community Level Physiological Profiling

Biodiversity has an important role in maintaining agroecosystem sustainability. A common strategy to increase agricultural biodiversity is by planting both harvested and unharvested (cover) crops simultaneously. This serves to increase primary production rates by increasing plant biomass which is expected to augment ecosystem services and increase soil organic matter. As above ground plant biomass increases, so does root biomass. Roots are one of the principal carbon sources which influence the function of soil microbes. Microbes utilize carbon in living and dead roots; however, microbes vary in their ability to metabolize root carbon. Evaluation of the functional diversity of soil microbes gives insight into soil health and agricultural sustainability. Community level physiological profiling (CLPP) is a way to measure the rate at which microbes are able to metabolize varying carbon sources. The microbial functional diversity was measured on four above ground treatments, each replicated on four unique plots, at three depths. Using average well color development (AWDC) of BioLog EcoPlates as a measure of microbial metabolic activity, we found that microbial functional diversity increases as above ground biomass increases and in soil closer to the surface