Comparative studies on composting efficiency of Eisenia foetida (Savigny) and Perionyx excavatus (Perrier).

Abstract

The potential of two epigeic earthworms (Perionyx excavatus and Eisenia foetida) was studied for composting of crop residues (wheat straw and paddy straw) amended with farm yard manure. At the end of vermicomposting significant increase in total nitrogen (71 -150%), phosphorus (49 %–116%) and potassium (26.3–142%), along with decrease in organic carbon was recorded in different experimental vermibeds. Maximum total nitrogen as well as available phosphorous concentration was observed from vermibeds inoculated with E. foetida, whereas increased exchangeable potassium and reduction in organic carbon was shown in vermicompost produced by P. excavatus. Enhanced hydrolytic enzyme activities of CMCases (1.51 folds), Fpases (2.11 folds) and β-glucosidases (1.38 folds) were recorded in treatments vermicomposted with P. excavatus. Microbial activity parameters such as dehydrogenase, FDA hydrolase, alkaline phophatase, were also monitored during decomposition process and gradual increase was recorded in vermibeds up to 90 days of experimentation. The mean individual live weight, growth rate (mg wt. worm -1 day-1 ) of earthworm were higher for P. excavatus as compared to E. foetida. Overall, P. excavatus exhibited better growth and mineralization efficiency, which further support the suitability of the species for large scale vermiculture operations.