This review article, authored by Mariangela Diacono and Francesco Montemurro, examines the long-term effects of organic amendments on soil fertility. The authors highlight the degradation of soils due to excessive use of agro-chemicals, deep tillage, and luxury irrigation, and the need for sustainable agricultural practices to address these issues. They focus on long-term experiments (3-60 years) that assess the impact of organic amendments on soil biological, chemical, and physical fertility, as well as plant nutrition and yield responses. Key findings include: 1. **Soil Biological Fertility**: Repeated application of exogenous organic matter improves soil biological functions, such as microbial biomass carbon and enzymatic activity. 2. **Soil Chemical Fertility**: Organic amendments increase soil organic carbon content, enhancing cation exchange capacity and nutrient retention. 3. **Soil Physical Fertility**: Organic amendments improve soil aggregate stability and reduce bulk density, leading to better water retention and resistance to erosion. 4. **Agronomic Performance**: High rates and frequent applications of compost can significantly increase crop yields, with up to 250% yield increases observed in some studies. 5. **Climate Change Mitigation**: Organic amendments play a positive role in carbon sequestration, contributing to climate change mitigation. 6. **Environmental Impact**: There is no evidence of negative impacts from heavy metals in organic amendments, especially when high-quality compost is used over long periods. 7. **Nutrient Cycling**: Organic amendments enhance nutrient cycling by stabilizing organic nitrogen content and reducing nitrate leaching to groundwater. The authors conclude that organic amendments, particularly compost, are effective tools for improving soil fertility and sustainability in agriculture, provided they are applied according to best practices and considering the specific characteristics of the soil and climate.This review article, authored by Mariangela Diacono and Francesco Montemurro, examines the long-term effects of organic amendments on soil fertility. The authors highlight the degradation of soils due to excessive use of agro-chemicals, deep tillage, and luxury irrigation, and the need for sustainable agricultural practices to address these issues. They focus on long-term experiments (3-60 years) that assess the impact of organic amendments on soil biological, chemical, and physical fertility, as well as plant nutrition and yield responses. Key findings include: 1. **Soil Biological Fertility**: Repeated application of exogenous organic matter improves soil biological functions, such as microbial biomass carbon and enzymatic activity. 2. **Soil Chemical Fertility**: Organic amendments increase soil organic carbon content, enhancing cation exchange capacity and nutrient retention. 3. **Soil Physical Fertility**: Organic amendments improve soil aggregate stability and reduce bulk density, leading to better water retention and resistance to erosion. 4. **Agronomic Performance**: High rates and frequent applications of compost can significantly increase crop yields, with up to 250% yield increases observed in some studies. 5. **Climate Change Mitigation**: Organic amendments play a positive role in carbon sequestration, contributing to climate change mitigation. 6. **Environmental Impact**: There is no evidence of negative impacts from heavy metals in organic amendments, especially when high-quality compost is used over long periods. 7. **Nutrient Cycling**: Organic amendments enhance nutrient cycling by stabilizing organic nitrogen content and reducing nitrate leaching to groundwater. The authors conclude that organic amendments, particularly compost, are effective tools for improving soil fertility and sustainability in agriculture, provided they are applied according to best practices and considering the specific characteristics of the soil and climate.