Modern crop production is sustained by the application of phosphorus fertilizers. The ultimate source of this phosphorus is non-renewable deposits of high-grade phosphate rock. The logistic costs of extracting and transporting a bulky commodity, along with unpredictable fluctuations of the global market, have seen fertilizer prices rise over recent years, with unanticipated spikes placing strain on already tight farm budgets. And yet, although great effort and resources are invested to deliver phosphorus to farmer’s fields, only a small percentage of what is applied is acquired by the plants. Much of the phosphorus is washed out to end up in water courses and, ultimately, the ocean, contributing to the well-documented environmental problem of algal blooms. In wild ecosystems, most plant species acquire phosphorus from the soil at high efficiency through association with symbiotic soil fungi. Staple crop species retain the capacity to form such fungal associations, but the system is far from optimized for agricultural conditions. This project will build on the latest molecular and genetic understanding of the mechanisms regulating cereal interactions with beneficial soil fungi. Specifically, the project will employ natural plant genetic variants to boost the level of interaction with soil fungi in corn and rice and evaluate the impact on plant performance under both standard and low phosphorus field conditions. Additional molecular studies will characterize the nature of the f