**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** THE FREQUENCY OF FLOOD EVENTS HAS CONTINUED TO RISE IN THE U.S. MIDWEST AND HAS RESULTED IN $7.7 BILLION IN DAMAGES FROM 2013-2017 ALONE. PAST RESEARCH HAS FOCUSED HEAVILY ON MANAGING FOR DROUGHT EVENTS, BUT MINIMAL EMPHASIS HAS BEEN PLACED ON MANAGEMENT FOR FLOODING EVENTS ALTHOUGH THE MAGNITUDE OF LOSS IS SIMILAR. THERE IS A CRITICAL NEED TO UNDERSTAND HOW ADVERSE WEATHER CONDITIONS ARE IMPACTING SOIL FOOD WEBS, NUTRIENT CYCLING PROCESSES, AND CROP ESTABLISHMENT AND YIELD IN ORDER TO IMPROVE NUTRIENT USE EFFICIENCY AND REDUCE LOSSES. OUR OVERALL OBJECTIVES ARE TO UNDERSTAND HOW FLOODING IMPACTS SOIL ECOSYSTEM FUNCTIONALITY AND DIVERSITY AND TO IDENTIFY KEY MANAGEMENT PRACTICES FOR USE IN CORN (ZEA MAYS L.) PRODUCTION TO MINIMIZE THE NEGATIVE EFFECTS OF FLOODING. THE SPECIFIC AIMS OF THE PROPOSAL ARE TO: 1.) DETERMINE HOW DIFFERENT COVER CROPS IMPACT WATER, NUTRIENT CYCLING, RHIZOSPHERE BIOLOGY, AND CROP YIELD IN THE EVENT OF FLOODING; 2.) MEASURE THE IMPACT OF N SOURCE (SYNTHETIC AND BIOLOGICAL) AND FLOODING ON NUTRIENT USE EFFICIENCY, YIELD AND RHIZOSPHERE BIOLOGY; AND 3.) DEVELOP A DIAGNOSTIC POST-FLOOD SOIL TEST FOR POST-FLOOD N RECOMMENDATIONS. EACH OBJECTIVE WILL BE ACHIEVED THROUGH IMPLEMENTING FIELD RESEARCH TRIALS REPLICATED IN TIME AND SPACE. SPECIFICALLY, THIS PROJECT WILL ADDRESS THE FOUNDATIONAL KNOWLEDGE OF AGRICULTURAL PRODUCTION SYSTEMS PROGRAM AREA PRIORITY BY INVESTIGATING EXPERIMENTALLY HOW NUTRIENT CYCLING AND SOIL COMMUNITIES ARE IMPACTED BY FLOODING AND MANAGEMENT PRACTICES. EMPHASIS WILL BE PLACED ON STUDYING SOIL BIOLOGICAL COMMUNITY STRUCTURE AND ACTIVITY, PLANT NUTRIENT UPTAKE AND USE EFFICIENCY, AND CROP YIELD AND QUALITY.