Characterization and Recycling of Organic Waste after Co-Composting - A Review

Co-composting produces a valuable compost material that can be used as valuable soil amendment. The process of the co-composting and control of the composting factors are the current challenges for the researchers. There are different factors that govern the quality, stability and the maturity of the co-compost in terms of amount of plant nutrients and reduction of heavy metals. Among these, C-N ratio is a parameter that can affect the loss of plant nutrients. Different studies showed wide ranges of C-N ratios (14-40) for maturity of quality compost. Temperature, aeration and types of the bulking agents also regulate the process of co-composting. Most widely used co-composted materials are animal manures with agro-wastes (sawdust, wheat straw, rice straw, corn stalks etc.). This practice brought substantial loss of heavy metals and maximum retention of plant nutrients. Higher nutrients contents of the compost and favourable soil properties as a result of co-composting of the saw dust, cow dung and egg shells have been reported. The application of co-composted dairy manure with wheat straw and sawdust produced higher plant biomass. Co-compost of cattle manure with rice straw produced an organic matter, total N and C-N ratio contents suitable for soil amendment. Therefore, this review focuses on the characteristics and utilization of organic waste after a reasonable co-composting process.