Echinochloa crus-galli, commonly known as Barnyard grass, cock spur grass or water grass, is a semi-aquatic weed that belongs to family Poaceae and genus Echinochloa with 250 known species all over the world. Native to Europe and India, it is one of the world’s ruinous weeds which have invaded grasslands, coastal forest areas, agricultural fields and roadsides of Asia, Australia and America (FAO, 2014). It was initially inducted for fodder in these regions. E. crus-galli weed is a persistent competitor of rice crop due to fast growth, rapid germinating ability, imitation of rice characteristics particularly during early growth and great plausible allelopathy (Zhang et al., 2017). In addition, it is considered among the top 15 herbicide resistant weeds, responsible for reducing rice yields (Yang et al., 2017) along with other crops like maize, soybean, lucerne, root crops, orchards (Holm et al, 1991). This annual grass about 1.5 cm in height has smooth, hairless and thickened culms with lateral branches, tufted stem and fibrous root system. With high invasiveness, super capacity to compete with rice, significant allelopathy and strong herbicide resistance, this weed is one of an important environmental invading species in India too.
While competing with rice, E.crus-galli produces 5000–7000 seeds that are capable of dispersion too far off places due to their more buoyancy than rice seeds (Barret and Wilson,1983), another aspect is that these seeds have different time of germination which relies on suitable environmental conditions. Therefore, its control becomes troublesome for agriculturalists and scientists. Besides using several control methods of clean cultivation, hand weeding, use of pathogens and use of allelopathy sound biological strategies are required to manage these weeds on site where they are produced. Earlier several researchers have employed different methods for managing aquatic, semi-aquatic and terrestrial weeds, viz., biogas production from Ipomoea, Eicchornia (Jain and Kalamdhad, 2018a), biopolymer production from Parthenium and Eicchornia (Pradhan et al., 2017), etc. Trending innovative alternative methods include use of weed biomass as feed material in composting and vermicomposting thus converting them to a valuable resource. Many vermicomposting studies have been carried out for some invasive weeds including water hyacinth (Gupta et al., 2007), Parthenium hysterophorus (Hussain et al., 2016) Pistia stratiotes (Suthar et al., 2017), Hydrilla verticillata (Jain and Kalamdhad, 2018b), Lantana camara (Devi and Khwairakpam, 2020a), Ageratum conyzoides (Gusain and Suthar, 2020a; Devi and Khwairakpam, 2020b), duck weed/Spirodela (Gusain and Suthar, 2020b), Ipomoea (Balachandran et al, 2020), etc. Vermicomposting is a bio-degradative process performed by earthworms jointly with microorganisms to convert waste materials into a stabilized vermicompost. Feedstock quality and earthworm species employed in vermi-conversion has a great impact on amount and quality of manure formed. Earthworm Eisenia fetida does a marvelous job of organic waste degradation due to its palatability for large variety of wastes, high fecundity, wide temperature tolerance and faster vermi-conversion. Incorporation of blending material in form of animal dung or any other substrate is pre-requisite for getting vermicompost of good manurial quality as well as to sustain vermicomposting. As per the available literature, no single study has been done on harnessing the potential of E. crus-galli weed in vermicomposting to provide a cost-effective and eco-friendly solution for its management. This perilous rice weed has been found in peri-urban areas (agricultural fields) of Faridabad city (Haryana, India) and despite control by burning, manual hoeing and herbicide use, its management is still a nuisance for local farmers. In the light of aforestated information, authors have made a small attempt to divert the attention of scientists and researchers towards sustainable management of rice weed Barnyard grass by earthworm mediated process – vermicomposting. Present investigation is probably the first ever study to vermi-transform E. crus-galli and recovering nutrients engaging earthworm Eisenia fetida. Several feed mix ratios were tested for suitability of weed E. crus-galli for vermi-conversion, increment in nutrient levels, effect on fecundity and earthworm growth, assessing maturity of vermicompost through evaluation of ash content, C: N & C: P ratios and respiration rate. This comprehensive study can lay a foundation for vermi-conversion of pernicious rice weed E. crus-galli and henceforth its subsequent management.