Soil is a natural habitat to wide variety of life forms including insects, arthropods and annelids. It is also a vital non-renewable resource for human, too. Chemical fertilizers have been used frequently to feed the mouth of millions and boost productivity. Overdose of chemical fertilizer has posed threat to various soil dwelling microorganisms and earthworm, too. In managed agro-ecosystem, Urea is widely used fertilizer used in crops as nitrogenous supplement. The present study outlines the detrimental effect of nitrogen supplements to earthworm. To determine dose response relationship earthworms Eisenia fetida were subjected to varying urea concentrations between 300 and 1500 mg/kg with a standard urea gap of 100 mg/kg. After 14 days, the percentage mortality in each treatment was noted. Ten adult gut cleaned worms were inoculated in artificial soil mixed along with testing chemicals. Experimental set-up was maintained as per the recommendations of OECD guidelines no 207 (1984, ISO, 2020) for testing of chemicals Earthworm. Results of this study indicate 300 mg/kg of urea as NOEC (No observed effect concentration) i.e highest Tested concentration for urea causing no mortality. In this experiment, all adult earthworms perished/were found dead at a urea concentration of 1500 mg/kg. The study therefore, recommends to use fertilizers of organic origin in the agricultural fields and minimizes, if cannot stop the use of chemical fertilizers in agricultural practices.

Earthworm, Eisenia fetida, Chemical fertilizers, Mortality, Urea