AGRICULTURAL SYSTEMS PLAY A KEY ROLE IN THE BALANCE OF GREENHOUSE GAS EMISSIONS (GHG). AGRICULTURAL SOILS ARE MAIN EMITTERS OF NITROUS OXIDE (N2O) AND, ALSO, THEY HAVE THE CAPABILITY TO SEQUESTER ATMOSPHERIC CARBON DIOXIDE (CO2). THE ADOPTION OF CERTAIN AGRICULTURAL MANAGEMENT PRACTICES MAY CONTRIBUTE TO DECREASE SOIL GHG EMISSIONS. IN RELATION WITH THE ROLE OF AGRICULTURAL MANAGEMENT ON CLIMATE CHANGE, THIS PROJECT AIMS TO IMPROVE THE KNOWLEDGE ON THE IMPACTS OF AGRICULTURAL MANAGEMENT PRACTICES ON GHG EMISSIONS IN MEDITERRANEAN RAINFED AND IRRIGATED CONDITIONS. IN SPAIN, THE AVAILABLE INFORMATION ABOUT THE ROLE OF AGRICULTURAL MANAGEMENT PRACTICES ON SOIL GHG (CO2, N2O Y CH4) EMISSIONS IS CONSTANTLY INCREASING. HOWEVER, MORE INFORMATION IS REQUIRED ON SOME PARTICULAR ASPECTS AND PRACTICES WHICH HAVE NOT BEEN ENOUGH STUDIED YET. IN THIS SENSE, THIS COORDINATED PROJECT IS FOCUSED ON THE STUDY OF FOUR MANAGEMENT PRACTICES IN FIELD CROPS: NITROGEN FERTILIZATION, SOIL AND RESIDUE MANAGEMENT, IRRIGATION MANAGEMENT AND CROPPING SYSTEM, WITH THE OBJECTIVE TO IDENTIFY MANAGEMENT PRACTICES WHICH MITIGATE SOIL GHG TO THE ATMOSPHERE. THE PROJECT WILL BE CONDUCTED ON TWO MAIN SPANISH AGRICULTURAL AREAS (THE EBRO VALLEY AND THE GUADALQUIVIR VALLEY) AND IT WILL INVOLVE SCIENTISTS FROM EIGHT DIFFERENT INSTITUTIONS SPLIT AMONG FOUR DIFFERENT SUBPROJECTS. SEVERAL INNOVATIVE ASPECTS ARE PRESENTED IN THE PROJECT. THUS, FOR INSTANCE, THE IMPACT OF SOIL MANAGEMENT (TILLAGE AND NO-TILLAGE) UNDER IRRIGATED CONDITIONS, IRRIGATION SYSTEMS AND FREQUENCY IN SPRINKLER IRRIGATION ON SOIL GHG EMISSIONS ARE PROPOSED. IN RELATION WITH FERTILIZATION MANAGEMENT, THE PROJECT WILL STUDY THE INTERACTION OF SOIL MANAGEMENT AND NITROGEN FERTILIZATION UNDER IRRIGATION CONDITIONS AND THE IMPACT OF NITRIFICATION AND UREASE INHIBITORS IN THE NITROGEN LOSSES BALANCE (LEACHING AND GASEOUS LOSSES). IN RAINFED CONDITIONS, THE PROJECT WILL INVESTIGATE THE IMPACT OF ALTERNATIVE CROPPING SYSTEMS TO THE TRADITIONAL CEREAL MONOCROPPING ON GHG EMISSIONS. IN THE PROJECT, THE MEASUREMENT OF SOIL GHG EMISSIONS FROM THE DIFFERENT MANAGEMENT PRACTICES WILL BE COMPLEMENTED WITH A SIMULATION STUDY AT DIFFERENT SCALES. THUS, MEASURED DATA WILL BE USED TO PARAMETERIZE AND VALIDATE THE DAYCENT MODEL FOR THE IRRIGATED CONDITIONS OF THE EBRO VALLEY AND THE GUADALQUIVIR VALLEY. ONCE VALIDATED, THE MODEL WILL BE USED TO BUILD A REGIONAL SCALE SIMULATION SYSTEM WITH THE HELP OF GEOGRAPHICAL INFORMATION SYSTEMS (GIS). AS INDICATED ABOVE, AGRICULTURAL SOILS ARE KEY EMITTERS OF GHG, THUS THIS PROJECT WILL CONTRIBUTE TO ESTABLISH MANAGEMENT STRATEGIES AND RECOMMENDATIONS ADAPTED TO OUR MEDITERRANEAN SYSTEMS AND FOCUSED TO MITIGATE GHG EMISSIONS FROM THE AGRICULTURAL SECTOR.