Microbial Influences on Decomposition and Soil Organic Matter Formation in Agricultural Soils

Intensive agricultural management often depletes soil organic matter (SOM), the largest terrestrial carbon (C) pool, and reversing or preventing this trend remains a major global challenge. Agricultural strategies for building SOM typically rely on increasing C inputs to soil but the effectiveness of this as a C sequestration strategy has been inconsistent. This is in part because the influence of soil microbial communities on the fate of C inputs is often overlooked and poorly understood, especially in response to agricultural management. My research is centered on understanding the interactions of soil microbial communities and agricultural land use on microbial decomposition and the formation and stabilization of microbial-SOM. Results from this work demonstrate that historical legacy is an important control on microbial decomposition and that agricultural systems which facilitate the transformation of plant C into microbial biomass may be an effective novel strategy for building SOM. Thus, in managing agricultural soils for C sequestration, we should go beyond simply C input quantity and consider how influences of land-use history and microbial physiology affect the fate of C inputs and subsequently SOM formation