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

nutrient runoff from agroecosystems is costly; it wastes fertilizer intended to promote higher crop yields, and it promotes algal and cyanobacteria growth in receiving waters that impairs water quality and causes significant economic and environmental losses. despite decades of research and the implementation of improved land and water management policies and practices, the problem of excessive nutrient losses from agroecosystems persists. one contributor to this continued challenge is our lack of fundamental understanding related to how microorganisms affect whether phosphorus is retained in the soil, available to crops, or lost to surface or subsurface flows. while considerable advancements have been made in modeling landscape-scale nutrient budgets, these models do not presently include microbial processes that are known to affect phosphorus retention to and release from soil. moreover, the responses of these microbial processes to precipitation and drying events are unknown. the goal of this project is to use recently developed advanced genetic tools to measure and track microbial responses to variable wetting conditions, to determine how these responses affect phosphorus solubility, and to improve models to include these mechanistic findings. the long-term goal of these activities is the development of land management strategies, potentially including engineered treatment approaches, to reduce phosphorus losses. achieving this goal will increase the efficient of nutrient applications for their intended purpose of promoting crop growth, while alleviating the detrimental impacts caused by current state-of-the-art approaches.