A review of additives use in straw composting

Straw composting is not only a process of decomposition and re-synthesis of organic matter, but also a process of harmless treatment, avoiding air pollution caused by straw burning. Many factors, including raw materials, humidity, C/N, and microbial structure, may determine the composting process and the quality of final product. In recent years, many researches have focused on composting quality improvement by adding one or more exogenous substances, including inorganic additives, organic additives, and microbial agents. Although a few review publications have compiled the research on the use of additives in composting, none of them has specifically addressed the composting of crop straw. Additives used in straw composting can increase degradation of recalcitrant substances and provide ideal living surroundings for microorganism, and thus reduce nitrogen loss and promote humus formation, etc. This review's objective is to critically evaluate the impact of various additives on straw composting process, and analyze how these additives enhance final quality of composting. Furthermore, a vision for future perspectives is provided. This paper can serve as a reference for straw composting process optimization and composting end-product improvement.