Recycling of organic wastes by improved techniques of composting and other methods

Abstract

The recycling of organic wastes for maintenance of soil quality and improved crop productivity is of economic importance. Composting is a microbiological, non-polluting and safe method for disposal and recycling of organic wastes by bioconversion to fertilizers. Efficient cellulolytic cultures, such as species of Aspergillus, Trichoderma, Penicillium and Trichurus, accelerate composting for efficient recycling of dry crop wastes with high C/N ratio and reduce the composting period by about one month. Enrichment of partially composted crop wastes can be achieved by Azotobacter and phosphate solubilizers to improve the nitrogen, available phosphorus and humus content of finished compost compared with controls. Amendment of the finished compost with 1% rock phosphate, and inoculation with nitrogen-fixing and phosphate-solubilizing bacteria, increased the nitrogen and humus content and decreased the C/N ratio of the compost. Blending of finished urban compost and fresh moist sludge, in a 2:1 proportion, and amendment with 1% rock phosphate, resulted in a compost rich in nitrogen with a C/N ratio less than 10. The composts prepared by improved techniques were found to increase the yields of crops.