Azolla Compost as a Sustainable Organic Fertilizer for Improving Soil Fertility and Crop Productivity

The increasing dependence on chemical fertilizers has contributed substantially to concerns regarding soil degradation, nutrient imbalance, environmental pollution, and the long-term sustainability of agricultural production, the use of locally available organic resources has gained considerable attention as an alternative or complementary approach to conventional fertilization. Azolla, a small floating aquatic fern belonging to the family Salviniaceae, is recognized for its rapid growth, high biomass production, and association with nitrogen-fixing cyanobacteria. These characteristics make Azolla a promising source of organic manure and compost. Azolla compost contains organic matter and essential plant nutrients and can contribute to improved soil structure, nutrient availability, microbial activity, and crop growth. Composting Azolla also provides an effective means of converting its rapidly produced biomass into a more stable organic fertilizer. This review discusses the biological characteristics and nutrient potential of Azolla, methods of Azolla compost production, its influence on soil physical, chemical, and biological properties, and its effects on crop productivity. The potential role of Azolla compost in sustainable agriculture, integrated nutrient management, and circular agricultural systems is also discussed. The available evidence indicates that appropriately prepared Azolla compost can serve as a valuable organic fertilizer, particularly when integrated with other nutrient-management practices. Further research is required to standardize composting methods, determine crop-specific application rates, evaluate long-term soil effects, and assess its economic feasibility under different farming conditions.