Chemical and Biochemical Changes during Vermicomposting and Conventional Composting of Different Organic Residues

Abstract

Composting basically being a microbiological process, enzymatic activities can be part of a reliable measureof compost stability and maturity. Assay of different chemical and biochemical changes during compostingis important for the optimization of the process and the quality of the end product. This study was,therefore, conducted to compare the chemical and biochemical properties of composts prepared from fourorganic residues of varying C/N ratios i.e. sugarcane trash, weeds, vegetable market waste and rice straw.Four residues were composted separately by vermicomposting and conventional method of composting.The results showed that vermicomposting is preferred over composting to overcome the deficiencies in thelong duration for decomposition apart from low nutrient status in composting. Total organic carbon (TOC)and C/N ratio decreased while total N content increased with the passage of time during composting in allthe organic residues, however the per cent decrease was more in vermicomposting than composting in aparticular period of time. Among different organic residues used for study highest total N content wasrecorded in vegetable market waste compost with a low C/N ratio, whereas reverse trend was observed incase of rice straw compost. The enzyme activities i.e. urease, phosphatase, dehydrogenase and cellulasewere decreased with increasing the composting period in all the organic residues. However, higher enzymeactivity was recorded in vermicomposting over composting of different organic residues and within theorganic residues, vegetable market waste recorded higher enzyme activities except cellulase, which washigher in rice straw compost. Weed compost exhibited on par with vegetable market waste. Type of organicresidue used for composting showed significant influence on chemical and biochemical properties.Vermicomposting should be preferred over composting with high N value and less C/N ratio apart fromhigh biochemical parameters.