Vermicompost using water hyacinth substrates enhance the biomass and population of Eisenia fetida and improve the chemical composition of compost

Abstract

Despite its destructive and harmful nature as one of the most prevalent and fast-growing weeds globally, water hyacinth (Pontederia crassipes) can be effectively recycled through vermicomposting, which is widely recognized as the preferred method for managing organic waste. The objective of this study was to investigate how water hyacinth biomass, when used as a material for vermicomposting in combination with weed biomass (including leaves, roots, or a mixture of both), affects the growth of Eisenia fetida (a type of earthworm) and the yield of vermicompost and its nutrient composition. Therefore, the option to transform water hyacinth into vermicompost using various weed substrates was conducted within a shaded concrete pit. The worms were fed five kg of water hyacinth leaves, and roots and both mixed along with 100 adults of Eisenia fetida earthworms. The vermicompost was watered and inspected gently every four days. After 120 days the vermicompost yield was measured and the worm biomass was counted. The number of young worms observed in various substrates showed that there were the most in the leaf substrate (2260), with slightly fewer in the mixed substrate (1280) and roots (1240). The highest amount of vermicompost was achieved using leaves as the substrate, with a yield of 3.672 kg. This was closely followed by the mixed substrate at 3.336 kg and the roots substrate at 3.033 kg. 0.88% - 2.34% Organic Carbon was analyzed in which the maximum result was in leaves compost. pH 7.73 to 7.99 which all are in alkaline ranges. While N was between 1.01 to 1.13% which was higher in leaves and lower in roots. 0.143% to 0.147% P were recorded and it was high in both mixed. K values were 0.2826% for leaves, 0.2899% for roots, and 0.3280% for both mixed respectively. Therefore, it can be concluded that earthworms can transform organic waste into a significantly more beneficial product through vermicomposting. In addition, the presence of earthworms in various substrates of water hyacinth increases the number of microorganisms found in the vermicompost.