Contrasting organic amendments and agricultural management: Effects on soil fertility crop productivity in the Mediterranean region

Soil organic matter depletion, climate change, and soil degradation threaten Mediterranean agriculture. This work assessed the effects of organic amendments (manure, straw, biochar, sewage sludge, and cover crops) on soil properties, plant growth, and nutrient dynamics under contrasting soil textures and cropping systems. Manure was the most effective for rapid fertility restoration, increasing biomass by 25-50% and improving nitrogen availability. Biochar enhanced soil structure and water retention and supported legume growth, with effects depending on soil and crop type. Straw contributed to long-term soil organic matter stabilization and increased soil carbon, though short-term growth was sometimes limited by nitrogen immobilization. Sewage sludge improved fertility but raised concerns about salinity and contaminants. Cover crops had limited short-term effects but improved soil protection and nutrient availability. Combining nutrient-rich inputs with long-term soil health practices is essential to enhance resilience and productivity.