Composite compost and its impact on soil health and crop productivity: a comprehensive review

Context Composite compost (CC), an advanced form of composting that integrates diverse organic feedstocks, has emerged as a sustainable solution for enhancing soil health and crop productivity. Unlike traditional single-feedstock compost, CC optimizes nutrient profiles, accelerates decomposition, and improves microbial diversity, resulting in higher humic content and reduced phytotoxicity. Aims This review paper synthesizes current knowledge on the composition, benefits, and challenges of CC, emphasizing its role in sustainable agriculture. Methods This comprehensive review was developed following PRISMA guidelines and synthesizes existing literature to assess the formulation, benefits, and challenges of CC. Key results Our study demonstrated that CC enhances structure, texture, water retention capacity, and nutrient profile of soils, while promoting beneficial microbial activity. Conclusions Application of CC has been shown to increase crop yields by 10–40%, improve crop quality, and enhance crop resistance to pests and diseases. However, challenges such as feedstock variability, seasonal variability, immature compost risks, and nutrient imbalance must be addressed through standardized production protocols. Implications The study indicates enormous potential of CC as a key element in sustainable soil management strategies, thus providing valuable directions to researchers, policymakers, and practitioners for promoting its use and setting standards. By bridging gaps in research and practice, CC offers a viable pathway toward soil restoration, climate resilience, and food security.