When the EU Soil Observatory stated that 61% of EU soils are in an unhealthy state, contamination was one of the main reasons. Common contaminants include persistent organic pollutants, drug and veterinary product residues, microplastics, and residues from excessive fertilizer or pesticide application. This chapter focusses on organic amendments in agricultural soils that have the potential to immobilize toxic trace elements and support the biodegradation of organic pollutants, by immobilizing and supporting microbiological degraders. The most commonly used organic amendments are compost, biochar and chitosan. The chapter reviews new developments in remediation treatments based on chemical modifications of classic amendments and/or the combination of different amendments. Complex contaminant mixtures require novel developments of tailor-made amendment combinations.