Physical degradation of agricultural and forest soils due to compaction ; Dégradation physique des sols agricoles et forestiers liée au tassement : principaux résultats du projet GESSOL ADD-DST

National audience ; Physical degradation of agricultural and forest soils due to compaction is an important concern for the actors in agriculture, forest and environment. Many questions are still pending on the importance of this degradation, the evaluation of its impact on environment, the effect of changes of climate and practices, its natural remediation. The DST (Agricultural and Forest Soil Degradation induced by Compaction ?) project has proposed a research action on soil compaction in metropolitan France in order to : quantify the impacts of soil compaction on important soil environmental functions ; identify the conditions leading to compaction ; prevent the occurrence of these conditions ; monitor the evolution of soil structure after compaction. The project was structured in five working packages : impact, prediction, prevention, follow-up and cartography. It was based on modelling (hydrology, soil deformation, soil-crop interactions models) to study the occurrence of compaction and its impacts on crop growth and the environment. It also aimed at developing non-destructive methods to monitor soil structure deformation. The project associated research laboratories working in agriculture, geophysics or civil engineering and extension services members and was also based on field and laboratory experimentations, performed in various conditions (field crops, vineyards, forests). Mains results concerned : (i) impacts of compaction, as we demonstrated the existence of a threshold value for the structural void ratio (0,15 m3m3 in loamy soils) beyond which crop performances and hydrological properties are systematically affected ; (ii) modelling, with a 2-D model of soil deformation ; (iii) compaction assessment, based on non-destructive geophysical methods ; (iv) prevention of compaction, with a predictive model of soil water content and (v) mapping of compaction risks in France, based on the knowledge acquired during the project. ; La degradación física de los suelos agrícolas y forestales ligada a la ...