** AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** AS AGRICULTURAL PRODUCTION SYSTEMS ARE CONFRONTED BY UNPRECEDENTED RECORD-BREAKING FLOODING EVENTS THAT THREATEN CROP GROWTH AND PRODUCTIVITY, PROFITABILITY, AND SUSTAINABILITY OF AGRICULTURAL ECOSYSTEMS AND FOOD SECURITY, THREE CRUCIAL QUESTIONS EMERGE:1.HOW DOES FLOODING ALTER THE FUNCTIONING AND STRUCTURE OF SOIL MICROBIAL COMMUNITIES THAT UNDERPIN PLANT AND SOIL HEALTH.2. HOW DOES FLOODING IMPACT CORN PLANT GROWTH AND TRAITS THAT PUTATIVELY MEDIATE PLANT AND INSECT INTERACTIONS.3. CAN POST-FLOODING NITROGEN MANAGEMENT RECOVER LOST YIELD POTENTIAL AND MAINTAIN CROP PRODUCTIVITY?THIS RESEARCH ADDRESSES TWO FOUNDATIONAL KNOWLEDGE OF AGRICULTURAL PRODUCTION SYSTEMS PRIORITIES: 1) DETERMINE HOW PRODUCTION SYSTEMS CAN ALTER PLANT AND SOIL MICROBIOMES, THE WAY ALTERATIONS AFFECT FUNCTIONS SUCH AS PLANT NUTRIENT UPTAKE, AND RESILIENCE TO INSECTS AND WEATHER EXTREMES ASSOCIATED WITH CLIMATE CHANGE AND OTHER STRESSORS; AND 2) INVESTIGATE HOW CHANGES TO CROPPING SYSTEMS AFFECT CROP PERFORMANCE, SOIL HEALTH, AND OTHER OUTCOMES BENEFICIAL TO SYSTEM RESILIENCE. THIS PROJECT WILL CHARACTERIZE THE IMPACTS OF FLOODING AND NITROGEN MANAGEMENT ON SOIL MICROBIOTA, CORN PLANT PHYSIOLOGY AND RESILIENCE, GRAIN YIELD AND NUTRITIONAL QUALITY, AND DEFENSIVE SECONDARY METABOLITES - TRAITS THAT ARE IMPORTANT MEDIATORS OF PLANT AND INSECT INTERACTIONS. NITROGEN AVAILABILITY MAY BE A STRONG DETERMINANT IN PLANT RECRUITMENT OF MICROBIAL COMMUNITIES AND HOW THEY INFLUENCE PLANT RESPONSES, SUCH AS ACC DEAMINASE PRODUCTION, TO FLOODING AND FINAL GRAIN YIELDS. RESULTS WILL PROVIDE CRUCIAL FOUNDATIONAL DATA ABOUT HOW SOILS, SOIL MICROBES, AND CORN PLANTS ARE AFFECTED BY FLOODING, WHICH GROWERS CAN USE WHEN MAKING POST-FLOOD MANAGEMENT DECISIONS, THEREBY MITIGATING THIS STRESS FOR CORN, AMERICA'S MOST ECONOMICALLY IMPORTANT CROP.