**AWARDS ISSUED PRIOR TO JANUARY 20, 2025, WERE FUNDED UNDER PREVIOUS ADMINISTRATIONS AND MAY NOT REFLECT THE PRIORITIES AND POLICIES OF THE CURRENT ADMINISTRATION.** BIOCHAR HAS ATTRACTED THE INTEREST OF FARMERS IN RECENT YEARS BUT ENTHUSIASM FOR ITS PUTATIVE BENEFITS AS A SOIL AMENDMENT HAS OUTPACED SCIENTIFIC UNDERSTANDING OF HOW AND UNDER WHAT CLIMATE, SOIL, AND MANAGEMENT CIRCUMSTANCES ITS BENEFITS CAN BEST BE ACHIEVED. THE OBJECTIVE OF OUR PROPOSED RESEARCH IS TO EVALUATE METHODS FOR PRODUCING AND ACTIVATING BIOCHAR AS A SOIL AMENDMENT FOR IMPROVING SOIL HEALTH IN DIVERSE MANAGED ECOSYSTEMS. OUR RESEARCH ADDRESSES THE PRIORITIES OF THE USDA BIOENERGY, NATURAL RESOURCES, AND ENVIRONMENT PROGRAM BY EXAMINING THE EFFICACY OF A NATURAL BIO-BASED PRODUCT IN PROMOTING AGROECOSYSTEM SUSTAINABILITY AND THE ESSENTIAL ECOSYSTEM SERVICES THAT SOILS PROVIDE. BIOCHAR APPLICATIONS IMPROVE SOIL HEALTH IN A VARIETY OF ECOSYSTEMS, PRIMARILY THROUGH MODIFYING SOIL MICROSTRUCTURE IN WAYS THAT ENHANCE AGGREGATION AND HYDRAULIC PROPERTIES. WE HYPOTHESIZE THAT THESE CHANGES IN SOIL MICROSTRUCTURE PROMOTE SOIL HEALTH BY INCREASING CARBON SEQUESTRATION IN AGGREGATESAND RETENTION OF WATER, AND NUTRIENTS AMONG SOIL MICROSITES. USING A COMBINATION OF FIELD EXPERIMENTS, ADVANCED IMAGING TECHNIQUES, AND MODELING WE WILL EXAMINE THE MECHANISMS BY WHICH BIOCHAR INFLUENCES SOIL STRUCTURAL AND HYDRAULIC PROPERTIES, AND THEREBY THE MOBILITY OF NUTRIENTS, CARBON SEQUESTRATION, AND MICROBIAL COMMUNITIES IN CONTROLLED FIELD STUDIES ACROSS A RANGE OF MANAGED AGRICULTURAL SYSTEMS (PASTURE, ROW-CROP, FOREST) AND SOIL TYPES (FINE AND COARSE TEXTURE SOILS ACROSS 6 ORDERS). THIS RESEARCH WILL INCLUDE NEW AND EXISTING BIOCHAR EXPERIMENTS TO ENCOMPASS A RANGE OF TEMPORAL PERSPECTIVES ON THE BENEFITS OF BIOCHAR TO GROWERS AND THE LONG-TERM IMPLICATIONS FOR HOW BIOCHAR POTENTIALLY INFLUENCES MULTIPLE INDICATORS OF SOIL HEALTH.