VERMICOMPOST PRODUCTION THROUGH HEAVY METAL ENRICH FEEDING MATERIAL: ACCUMULATION IN EARTHWORM'S BODY AND ITS CONSEQUENCES FOR QUALITY

Two experiments were conducted from January to April 2024 at the vermicompost shed and laboratory of the Department of Soil Science, Sylhet Agricultural University. The study aimed to determine the concentration of heavy metal accumulated in earthworm's body after vermicomposting and the physicochemical changes in produced vermicompost from cow dung. Both experiments were carried out by using two factors completely randomized designs (CRD) with three replications. In 1st experiment, factor A comprised of two earthworm species viz., Eisenia fetida and Eudrilus eugeniae; and factor B consisted of four concentrations of lead and chromium were applied; viz., i) Control (natural presence of Pb and Cr) ii) Pb (10 ppm), iii) Cr (0.7 ppm), iv) Pb+Cr (10+0.7, ppm). Twenty-five earthworms were released into 500 g of cow dung as feeding material in each bowl. The results showed that the physical characteristics of vermicompost were dark brown, ammonia off odour, non-granular and not sticky. The highest number of earthworms, hatchlings, and cocoons were 26.61, 17.33, and 66.50 bowl-1 found at control, respectively.