From Waste to Soil Fertility: Comparative Assessment of Anaerobic Digestion and Aerobic Composting in Agricultural Sustainability

The increase in organic waste production, demographic growth, urbanization, and the intensification of agricultural activities have increased the need for sustainable nutrient recycling. Biological treatment of organic waste, represented by composting and anaerobic digestion, is one of the most effective solutions. Compost and digestate are the main products of these processes. These materials meet circular economy principles, though their chemical characteristics and agricultural functions differ. Digestate is rich in minerals readily assimilated by plants, providing rapid nutrient supply. Compost releases nutrients more slowly and contains stable organic matter that improves soil fertility and structure over time. If appropriate agricultural practices are not applied, rapid nutrient availability may lead to risks such as nutrient loss, salinity, or plant phytotoxicity. Compost and digestate are complementary. Their combined use can balance rapid plant nutrition with long-term improvements in soil’s physical and chemical properties and reduce reliance on mineral fertilizers.