Vermicomposting of invasive weed Ageratum conyzoids: Assessment of nutrient mineralization, enzymatic activities, and microbial properties

Abstract

Ageratum conyzoids biomass was vermicomposted with cow dung in 25 (T25), 50 (T50), and 75 (T75) % (v/v) ratios and changes in physicochemical characteristics, enzymatic activities (proteases, dehydrogenases, β-galactosidase and phosphatases), and microbial population (bacterial, fungal, and actinomycetes) was recorded. Vermicomposting caused a decrease in pH, OCtotal (27.3–35.3%), but an increase in Ntotal (59.6–69.9%), Paval (53.8–148.7%), Ktotal (32.2–92.43%), and Catotal (25.5–55.3%). The peaked enzymatic activities were recorded between 5 and 15 d. T50 and T75 showed the highest fold increase in bacteria (2.09-to-2.51), fungi (1.48-to-2.41), actinomycetes (1.52-to-1.79) population. The maximum biomass (883.67–1480 mg), cocoon production (85.33–145.33), and population build-up in earthworm were recorded in setups with a high content of Ageratum. Germination index (>80%) and soil respiration rate suggested the non-toxic impact of vermicomposted Ageratum. Results indicate that Ageratum could be biotransformed into toxic-free manure through vermitechnology.