Bioconversion of phytotoxic terrestrial weeds into soil conditioning bioproduct through two-stage biodegradation process

Mikania micrantha Kunth and Ageratum conyzoides are the most toxic and noxious terrestrial weeds of concern. The present research focuses on the bioconversion of these terrestrial weeds through an optimised biodegradation process: Degradation of feedstock initially in an in-vessel reactor (rotary drum) and further by introducing vermiculture (RDVC). RDVC was optimised to utilise the in-vessel reactor for initial thermophilic degradation of feedstock for 7 days and further vermicomposting using monocultures of Eudrilus eugeniae and Eisenia fetida for 20 days. In contrast with only in-vessel biodegradation, the results of the present study evidence that the significance of dual-stage biodegradation was coherent in the bioconversion of weeds. The vermicompost amended trials had shown greater nutritional value (Total nitrogen in the range of 2.89–3.92%) by the end of 27 days of RDVC. Further, the SGI% was more than 80%, which signifies the soil-safe performance of vermicompost. Among the conducted soil studies with end products, higher growth in Coriandrum sativum was observed in 20% (w/w) vermicompost amended trials. Also, the metal study signifies that the RDVC was coherent in the bioaccumulation of metals during biodegradation. The outcomes of this study can assist Agro policymakers in effectively utilising weed biomass.