Co-composting invasive aquatic macrophytes and pond sediment holds the potential for environmental amelioration: Selecting the right shade of grey

Co-composting of invasive aquatic weeds with pond sediment can be a cost-effective way to manage the problem of invasion and eutrophication in aquatic systems and improvement of soil fertility in agricultural systems. Nevertheless, preparation of good quality compost is a challenge because of the variations in the physico-chemical properties of the plant material and the bulking agent. Mixing the plant biomass and the bulking agent in an appropriate proportion is crucial to make good quality compost, which requires a systematic empirical study. We standardized a protocol for composting Eichhornia crassipes and Ipomoea carnea biomass using pond sediment as a bulking agent. For each species, we used a randomized block design with 3 treatments × 3 replicates. The study revealed that mixing pond sediment and the weed biomass in 1:5 ratio yielded better quality compost in both the species compared to other treatments. The study emphasizes that composting aquatic weeds with pond sediment should help in managing the problem of weed invasion, sedimentation, eutrophication, and loss of soil fertility in agricultural fields.