SOILS ARE ONE OF OUR MOST VALUABLE RESOURCES. IN AGRICULTURAL SYSTEMS, MANAGEMENT PRACTICES THAT ENSURE HIGH YIELDS OFTEN HAVE NEGATIVE EFFECTS ON SOIL BIOLOGY. MANY CURRENT SOIL HEALTH ASSESSMENTS DO NOT ALLOW FOR A NUANCED ASSESSMENT OF SOIL BIOLOGICAL HEALTH. HOWEVER, TO ENSURE THE LONG-TERM SUSTAINABILITY OF CROPPING SYSTEMS, BOTH, THE WELLBEING OF SOIL MICROORGANISMS AND CROPS NEED TO BE TAKEN INTO ACCOUNT.WE PROPOSE IDENTIFYING BIOLOGICAL INDICATORS OF SOIL HEALTH AND COMBINE THEM WITH SOIL PHYSICOCHEMICAL PARAMETERS THAT ARE COMMONLY USED IN SOIL HEALTH ASSESSMENTS. THE CORE ASSUMPTION OF THE PROPOSED RESEARCH IS THAT HEALTHY SOILS PROVIDE AN ENVIRONMENT FOR SOIL MICROORGANISMS AND PLANTS THAT MINIMIZES STRESS. THE HYPOTHESIS THAT MICROBIAL AND PLANT STRESS INDICATORS CAN INFORM THE SOIL HEALTH STATUS WILL BE TESTED IN A LONG-TERM FIELD COMPARISON OF AGRICULTURAL SYSTEMS (ORGANIC AND CONVENTIONAL), A GREENHOUSE STUDY AND IN COMMERCIAL FIELDS. MICROBIAL STRESS WILL BE ASSESSED BY MICROBIAL COMMUNITY ANALYSIS AND BY METAGENOMICS ANALYSES TARGETING SPECIFIC TRANSCRIPTIONAL REGULATOR GENES EXPRESSED UNDER ENVIRONMENTAL STRESS CONDITIONS. PLANT STRESS WILL BE ASSESSED BY MEASURING PHOTOSYSTEM II ACTIVITY, STRESS-RELATED HORMONES, BIOMASS PRODUCTION AND NUTRIENT UPTAKE.