effect of corn waste blended with cow dung and paper on vermicompost qualities using eisenia fetida

harvesting corn created annually a large amount of organic waste, which could be a suitable initial substrate for vermicomposting due to its high c/n ratio. the present study was aimed for recycling of corn residues and production of good quality vermicompost, after processing by eisenia fetida. the setup of experiments was conducted with 40, 60 and 80% of corn residue, compost, cow dung and paper. the mixtures were precomposted for 30 days to improve substrate for earthwprms and then vermicomposted for 40 days. the results showed that toc, tvs and c/n ratio was decreased in all treatments, while value of ec, tkn, tp, nitrate, heavy metals and other nutrients increased. with increasing corn residue from 40 to 80% in the substrates, the value of tkn and nitrate decreased significantly from 1.96 to 1.60% and from 1780 to 1458 mg/kg, respectively. however, comparable increase of toc from 28.11 to 33.80%, tvs from 44.41 to 51.97%, c/n ratio from 14.42 to 21.18, tp from 3.20 to 3.80 g/kg and ec from 2.97 to 3.48 ms/cm was obtained. results of this study revealed that bledding materials (corn residue with compost, cow dung and paper) were more suitable vermicomposting production. the mixtures with a corn residue of 80% had more positive effects on final vermicompost quality. therefore, the reproducibility of the process and the quality of the final products make it possible to propose the use of this experimental procedure for research requiring a mass reduction of the initial composting of agricultural waste mixtures.