Asian Journal of Research in Agriculture and Forestry

Elephant dung (ED) is one of the major waste products that cause the spread of pathogens, bad odours, and waste gases, creating an unpleasant environment. Vermicomposting is a beneficial way to dispose ED to reduce the problem engaged. Therefore, the present study aimed to utilize ED for okra (Abelmoschus esculentus) cultivation (variety Radha) through vermicomposting using the earthworm species Eisenia fetida. The experiment was conducted at the University of Colombo Institute for Agro-technology and Rural Sciences (UCIARS), Weligatta, Hambantota, Sri Lanka, from December 2024 to April 2025. Two separate experiments were carried out in a Completely Randomized Design (CRD) with three replications for each treatment of Experiment 01, and four replications for each treatment of Experiment 02. The first experiment consisted of 7 treatments containing different ratios of cow dung, and ED decomposed for 24 hours, 7 days and 30 days. The second experiment consisted of 9 potting mixtures prepared by mixing top soil and sand with typical compost and vermicompost produced from each treatment of Experiment 01. In the first experiment, the pH value of all treatments were in a slightly alkaline range of 7.28 – 7.92, and with a significant difference among them. Nitrogen and Potassium contents varied significantly among treatments with E₁T₂ (24 hours decomposed ED) producing a higher nitrogen level of 1.25% and a higher potassium level of 0.034%. The phosphorus content remained statistically insignificant among treatments within a range of 0.19 – 0.42%. The earthworm count increased 9-12 folds in different treatments with E₁T₂ and E₁T₄ (7 days decomposed ED) producing higher results (562 and 566 respectively) compared to others, indicating the suitability of ED as a substrate for E. fetida. The vermicompost yield produced significant differences among treatments within a range of 3.95 - 5.08kg, with E₁T₆ (30 days decomposed ED) and E₁T₇ (30 days decomposed ED + cow dung) performing better than other treatments, producing 5.08kg and 5.01kg respectively. In the second experiment, plant height, number of leaves per plant, days to flowering, and the total yield did not differ significantly among treatments. Therefore, the findings of this experiment reveal the potential of vermicompost prepared from ED as an eco-friendly and sustainable approach for ED waste management, and okra cultivation without negatively affecting its yield.