METATRANSCRIPTOME AND REDOX SIGNATURES OF MICROBIALLY CATALYZED PHOSPHORUS MOBILIZATION IN AGRICULTURAL LANDSCAPES

Our project focuses on the knowledge gap of microbial activities that directly affect the transport and retention of phosphorus (P) in agricultural landscapes. The long-term goal of this research effort is to complement and improve the existing and emerging tools for developing better land- and water-management strategies, with respect to improving P utilization and conservation, by integrating the fundamental framework of microbial mechanisms. Achieving this goal necessitates more information on the prevalence, diversity, and activities of relevant microbial populations and how these correlate with variations in hydrologic and temperature determinants at an event-scale, or "hot-moment," temporal resolution. This builds on our prior USDA-supported research on P "hot-spots," i.e., small parts of the landscape where biogeochemical processes are disproportionately high.To address these broad goals, we have designed a research scope with the following specific objectives:O1 - Landscape-scale monitoring: refine the temporal resolution of landscape-scale study by capturing fine-timescale dynamic responses to wetting/drying events. We will focus on microbial and physicochemical determinants that influence P mobility. O1a - Metatranscriptomics: capture transient activities relevant to P mobilization and retention that are masked in metagenomic characterizations due to archival and unexpressed DNA, andO1b - Redox potential: test whether real-time monitoring of redox potential provides easily measureable and interpretable correlations to relevant microbial activities.O2 - Water quality model refinement: assess the addition of a microbially informed P-load modeling component to an online water quality tool as a beta-test to potentially adding similar functionality to more widely used watershed models.