Vermicomposting of duckweed (Spirodela polyrhiza) by employing Eisenia fetida: Changes in nutrient contents, microbial enzyme activities and earthworm biodynamics
키워드
요약
This study investigated the vermicomposting of duckweed (DW) mixed with cow dung in 25 (T25), 50 (T50), 75 (T75), 100% (T100) ratio using Eisenia fetida under a 35 d trail. Decrease in pH, organic carbon (33.54-38.25%), C/N ratio (43.6-56.6%), but increase in total N (18.2-42.4%), Paval (137-187%), and TK (7.76-79.4%) was recorded. Macro-elements (Mg, Fe, Zn, Mn, and Cu) also showed a many-fold increase in vermicomposts. T50 and T75 showed the highest mineralization rates. Activities of enzymes (proteases; dehydrogenases; β-galactosidase; acid phosphatase; and alkali phosphatases) and soil respiration rate was also higher in DW-rich waste mixtures. Seed bioassay test indicates the high agronomic application of DW-based vermicomposts. High earthworm biomass (975-1395 mg) and fecundity rate (1.53-4.07 cocoons worm-1) was recorded in all vermi-setups suggesting the suitability of DW as a substrate for E. fetida culture.
Keywords: Aquatic weeds; C/N ratio; CO(2) emission rate; Germination index; Microbial enzymes; Vermicomposting.