SYNTHETIC NITROGEN (N) FERTILIZER IS ONE OF THE MOST EXPENSIVE AND ENERGY-INTENSIVE INPUTS TO PRODUCE IN AGRICULTURAL PRODUCTION SYSTEMS WORLDWIDE. INEFFICIENT USE OF N FERTILIZERS IN AGRICULTURE LEADS TO A HOST OF ENVIRONMENTAL AND ECONOMIC CONCERNS. TO ALLEVIATE THE ENVIRONMENTAL BURDENS AND INCREASE FARMING PROFITABILITY, IT IS CRITICAL TO IDENTIFY SUSTAINABLE ALTERNATIVES TO IMPROVE MAIZE NITROGEN USE EFFICIENCY (NUE). ROOT-ASSOCIATED MICROBIOMES REPRESENT AN IMPORTANT AVENUE TO SUSTAINABLY IMPROVING AGRICULTURAL PRODUCTIVITY AND NUE. IN THIS PROJECT, WE WILL USE A SET OF BENEFICIAL MICROBES THAT PREVIOUSLY IDENTIFIED AND TEST WHAT ARE THEIR EFFECTS ON PLANT PERFORMANCE. ADDITIONALLY, WE WILL PROFILE THE ROOT-ASSOCIATED MICROBIOME COMPOSITION IN A SET OF UNDERUTILIZED MAIZE GENETIC MATERIALS UNDER HIGH N AND LOW N CONDITIONS. FINALLY, WE WILL DEVELOP A MICROBIOME-ENABLED STATISTICAL MODEL TO FACILITATE PLANT BREEDING. THROUGH THIS PROJECT, WE WILL INTEGRATE STATE-OF-THE-ART METAGENOMICS, QUANTITATIVE GENETICS, STATISTICAL GENOMICS, AND HIGH-THROUGHPUT PHENOTYPING APPROACHES TO HARNESS THE SYMBIOTIC PARTNERSHIP FOR MAIZE NUE IMPROVEMENT. THE KNOWLEDGE AND THE RESULTING MICROBIOME-ENABLED METHOD WILL POSITIVELY IMPACT MAIZE PRODUCTION SYSTEMS AND THE SUSTAINABILITY OF U.S. AGRICULTURE.