Decomposition of poultry litter through vermicomposting using earthworm Drawida sulcata and its effect on plant growth

Abstract

Poultry litter contains an enormous amount of nutrients that create environmental problems like eutrophication and phytotoxicity. These challenges can be mitigated by stabilizing its nutrients using earthworms. The objective of the present study was to decompose poultry litter amended with cow dung and Tectona grandis leaf litter into vermicompost (VC) using Drawida sulcata, relatively a new earthworm species. D. sulcata is a hardy species, and its survival rate was high during the vermicomposting process under alkaline pH condition. D. sulcata improved the quality of vermicompost by increasing the level of nutrients like total nitrogen, total phosphorous and total potassium and decreased pH, organic carbon and carbon/nitrogen ratio. The quality of VC was checked through seed germination assay using Trigonella foenum-graecum. In comparison with control, 20% (20 g VC + 100 ml water) concentration of VC extract showed a statistically significant (P < 0.05) increase in seed germination, while 100% (100 g VC + 100 ml water) a decreased seed germination displaying phytotoxicity. Plant growth studies using Abelmoschus esculentus were conducted by amending soil with different concentrations of VC such as V1 (100% soil + 25% VC), V2 (100% soil + 50% VC), V3 (100% soil + 75% VC), V4 (100% soil + 100% VC) and control (C) (1 kg garden soil). Maximum plant growth was noticed in V3 and V2 treatments. The present study confirms that D. sulcata, an epigeic earthworm, can be used for in situ degradation of poultry litter.