ORGANIC FARMING SYSTEMS RELY ON BIOLOGICALLY MEDIATED PROCESSES TO PROVIDE PLANTS WITH ESSENTIAL NUTRIENTS AND TO SUPPRESS PESTS. THIS RELIANCE IS CENTRAL TO THE SOIL HEALTH CONCEPT, BUT SURPRISINGLY LITTLE SOIL HEALTH RESEARCH HAS BEEN CONDUCTED IN CERTIFIED ORGANIC SYSTEMS. ORGANIC GROWERS FACE ADDITIONAL CHALLENGES ASSOCIATED WITH THE NEED FOR MECHANICAL TILLAGE, WHICH IS KNOWN TO DECREASE SOIL ORGANIC CARBON AND AGGREGATION AND INCREASE SOIL EROSION, TO CONTROL WEEDS. GROWERS NEED SCIENCE-BASED TRAINING TO BUILD SOIL HEALTH USING ORGANIC-APPROVED MANAGEMENT OPTIONS. TO ADDRESS THIS NEED WE BRING TOGETHER RESEARCH AND EXTENSION SCIENTISTS, EXPERIENCED IN SOIL ECOLOGY AND SOIL HEALTH, TO DELIVER RELEVANT INFORMATION TO HELP GROWERS MANAGE FOR SOIL HEALTH AND PRODUCTIVITY. WE PROVIDE TOOLS AND TARGETS TO GUIDE SOIL MANAGEMENT DURING THE TRANSITION TO ORGANIC, THEREBY INCREASING SOIL HEALTH AND FUNCTION OF ORGANIC SYSTEMS. THE SPECIFIC GOAL OF THIS PROJECT IS TO IS TO FACILITATE THE DEVELOPMENT OF RESILIENT CERTIFIED ORGANIC FARMING SYSTEMS IN IDAHO AND EASTERN WASHINGTON THROUGH ENHANCED KNOWLEDGE OF THE IMPACTS OF TILLAGE MANAGEMENT AND ORGANIC AMENDMENTS ON SOIL BIOLOGICAL COMMUNITIES AND SOIL HEALTH, AND TO USE THIS KNOWLEDGE TO CREATE MEANINGFUL SOIL HEALTH TARGETS AND PATHWAYS TO SUCCESS FOR TRANSITIONING FARMERS. SPECIFIC AND INTERRELATED RESEARCH (R) AND EXTENSION (E) OBJECTIVES THAT DIRECTLY RELATE TO KEY BARRIERS TO SUCCESSFUL TRANSITION TO ORGANIC PRODUCTION WERE DEVELOPED TO ACHIEVE THIS GOAL. THEY INCLUDE:R1) ASSESS THE INTERACTION BETWEEN TILLAGE AND ORGANIC INPUTS AND HOW THESE PRACTICES IMPACT SOIL HEALTH INDICATORS AND YIELDS IN TRANSITIONAL SYSTEMS LOCATED IN TWO DIFFERENT CLIMATIC ZONES.R2) USE POPULATION AND COMMUNITY STRUCTURES OF NEMATODES, ARTHROPODS, AND EARTHWORMS TO ASSESS CHANGES IN SOIL HEALTH UNDER THREE DIFFERENT MANAGEMENT STRATEGIES DURING THE TRANSITION TO ORGANIC CERTIFICATION, WITH SPECIAL FOCUS ON KEY PEST AND BENEFICIAL SPECIES.R3) ASSESS A SUITE OF SOIL HEALTH INDICATORS TO DETERMINE HOW THEY CAN BE USED TO PREDICT MANAGEMENT AND YIELD POTENTIAL IN DIFFERENTLY AGED ORGANIC CERTIFIED SYSTEMS.RE4) DEVELOP, IN COLLABORATION WITH FARMERS, MEANINGFUL SOIL HEALTH TARGETS BASED ON KNOWLEDGE OF HOW INDICATORS VARY OVER TIME AND SPACE IN TWO CLIMATIC ZONES.E5) UTILIZE EXISTING FARMER NETWORKS TO CREATE REGIONAL LEARNING COMMUNITIES FOR SHARING BEST PRACTICES AND SOIL HEALTH SUCCESSES.E6) INCREASE KNOWLEDGE OF SOIL HEALTH, SOIL TESTING, AND CONSERVATION TILLAGE OPTIONS THROUGH DISSEMINATION OF PROJECT RESULTS.