**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** TILLAGE IS AN ESSENTIAL FARMING PRACTICE THAT IS CLOSELY TIED TO PRODUCTION COST, CROP YIELD, AND ENVIRONMENTAL SUSTAINABILITY. THE U.S. MIDWEST HAS SEEN A RECENT TREND OF SHIFTING FROM CONVENTIONAL TILLAGE TO MORE CONSERVATION TILLAGE (E.G., NO-TILL), THOUGH THE ADOPTION RATE OF NO-TILL IS STILL LOW (~35% BY 2017) AND ITS CHANGE IS RELATIVELY STAGNANT. HOWEVER, THERE IS STILL NO CONSENSUS IN THE EXISTING SCIENTIFIC LITERATURE ABOUT THE IMPACTS OF CHANGING TILLAGE PRACTICES ON CROP PRODUCTION AND ENVIRONMENTAL SUSTAINABILITY, MAINLY BECAUSE OF THE SPATIALLY VARYING SOIL, WEATHER, AND MANAGEMENT CONDITIONS. HIGH-RESOLUTION SPATIALLY-EXPLICIT ASSESSMENTS OF TILLAGE IMPACTS ARE MOSTLY LACKING IN THE U.S. MIDWEST, AND ARE CRITICALLY NEEDED FOR FARMERS TO MAKE THE MOST INFORMED DECISIONS FOR THEIR FIELDS.IN THIS PROJECT, WE AIM TO INNOVATIVELY INTEGRATE META-ANALYSIS, AIRBORNE AND SATELLITE DATA, AND PROCESS-BASED MODELING TO CONDUCT HIGH SPATIOTEMPORAL ASSESSMENTS OF TILLAGE IMPACTS ON CROP PRODUCTIVITY AND ENVIRONMENTAL SUSTAINABILITY IN THE U.S. MIDWEST. THE FOLLOWING FOUR MAJOR MIDWEST STATES WILL BE INCLUDED AS OUR STUDY DOMAIN: ILLINOIS, INDIANA, IOWA, AND MINNESOTA. IN PARTICULAR, WE WILL STUDY THE TILLAGE IMPACTS ON CROP YIELD OF CORN AND SOYBEAN (THE TWO DOMINANT CROPS GROWN IN THE U.S. MIDWEST), AND SEVERAL ENVIRONMENTAL SUSTAINABILITY METRICS: GREENHOUSE GAS EMISSION, NITROGEN LEACHING, CHANGES IN SOIL ORGANIC CARBON, AND SOIL EROSION. WE AIM TO ACHIEVE THE FOLLOWING OBJECTIVES: (1) COLLECT HISTORICAL FIELD DATA FROM THE LITERATURE TO CONDUCT META-ANALYSES TO QUANTIFY IMPACTS OF VARIOUS TILLAGE PRACTICES ON CROP YIELD AND ENVIRONMENTAL SUSTAINABILITY METRICS; (2) USE AIRBORNE HYPERSPECTRAL IMAGING DATA, MULTI-SENSOR FUSED SATELLITE DATA, AND MACHINE-LEARNING ALGORITHMS TO MAP FIELD-SCALE TILLAGE PRACTICES FOR THE HISTORICAL PERIOD (2000-2023) FOR THE FOUR MAJOR MIDWEST STATES, AND QUANTIFY TEMPORAL TRENDS OF TILLAGE PRACTICES AT THE FIELD SCALE; (3) USE LONG-TERM EXPERIMENTAL DATA, META-ANALYSIS RESULTS, AND SATELLITE-BASED MEASUREMENTS TO CONSTRAIN AND VALIDATE THE ECOSYS MODEL SIMULATION ON TILLAGE IMPACTS FOR CROP YIELD AND ENVIRONMENTAL SUSTAINABILITY; AND (4) QUANTIFY THE IMPACTS OF TILLAGE PRACTICES ON CROP PRODUCTION AND ENVIRONMENTAL SUSTAINABILITY USING THE CONSTRAINED ECOSYS MODEL AND SATELLITE-BASED TILLAGE MAPS FOR THE MAJOR MIDWEST STATES AND CONDUCT SUITABILITY ASSESSMENT OF TILLAGE PRACTICES TO SUPPORT POLICY DESIGN AND FARMERS' DECISION MAKING.