Plastic pollution might lead to the degradation of soils, with major environmental and economical costs for agriculture. Considering the multiple facets of plastic pollution (contaminant cocktails including additives and non-intentionally added substances NIAS, added alone in mulching or closely entangled with residual organic matter in amendments), this project will take a lead in assessing the extent of this threat and propose ways to remediate it. With a novel methodology based on a back and forth collaboration between polymer chemistry and soil ecology we will explore several exposure scenarios of soil organisms to custom-made plastics, deciphering their toxicity in different environmental compartments (rhizosphere, microorganisms, mesofauna, plastisphere), their impacts on soil functions and on biogeochemical cycles, their dynamics and that of plastic-associated microorganisms and the physico-chemical and microbial retroactions of soils on plastics.