1. Introduction
We have recently developed the concept of ‘high-rate vermicomposting’ (Abbasi et al., 2015) which enables substrates such as weeds, agricultural waste, and paper waste to be directly and rapidly vermicomposted. Pre-existing vermireacors have been unable to handle such wastes for reasons detailed earlier (Abbasi et al., 2015). We have also shown that vermicomposts derived from even toxic and allelopathic weeds like parthenium and ipomoea are benign organic fertilizers, as effective as manure-based vemricomposts are known to be (Hussain and Abbasi, 2018). The machine acronymed HEVSTOW (High Efficiency Vertically Stacked vermicomposting system for Treating Organic Waste), being presented here, has been designed to derive maximum advantage from the positive attributes of the high-rate vermicomposting paradigm. No similar machine has been designed or developed earlier, and after ascertaining its novelty in the context of global prior art, a patent has been granted to it (Tauseef et al., 2018). In the present paper the efficacy of the machine has been demonstrated by its utilization in simultaneous vermicomposting of two different substrates with two different species of earthworms.