Gupta, R.K.Yadav, Jyoti2016-09-202016-09-202014http://krishikosh.egranth.ac.in/handle/1/77625A study of 90 days duration was conducted to evaluate the efficiency of an exotic earthworm species (epigeic- Eisenia foetida ) for decomposition of different kind of organic substrates. Five experimental vermibeds along with three replicates each were prepared by using cowdung along with different combinations of wheat straw, rice straw, vegetable waste and sugarcane baggasse having ratio 5:1. The result obtained indicates reduction in C: N ratio, which indicates the reduction in biodegradable organic content and increase in nitrogen content. The decrease in carbon and increase in nitrogen content improves the quality of vermicompost as manure. The best results of vermicomposting have been obtained from the substrate having cow dung and rice straw (5:1) due to the probability that rice straw is easily palatable and digestible for earthworms having constant pH. Then the survivability and reproduction rate of earthworms was checked on weekly intervals for one month which showed least survivability in case of Cd (0.06 ppm) followed by Cd(0.03 ppm) + Zn (0.03 ppm). Cocoon production rate and hatchling rate declined at high concentrations of heavy metals individually as well as in combination. Sewage also showed the significant decline in survivability, cocoon production rate as well as in number of hatchlings per cocoon. Then the effect of heavy metals on the biomolecular concentration of earthworms was analyzed for three months at interval of 45 days where sewage did not showed the significant differences in the biomolecular concentration as compared to the control. The maximum reduction among all heavy metals treatment was seen in the case of cadmium (0.06 ppm). Thus the study proves that Cadmium is more toxic and detrimental to earthworms as compared to control.enEisenia foetida, Vermicompost, Hatchling,, Survivability, CocoonThesis