Vermicompost as an alternative of management for water hyacinth

Aquatic weeds, such as Eichhornia crassipes (Mart.) Solms (water hyacinth) can be used as raw material for vermicompost. Vermicompost is the product of microbial decomposition of organic waste through the digestive tracts of earthworms. The aim of this work was to use water hyacinth to obtain stable and mature vermicompost. Three treatments were performed for vermicomposting, treatment one with 100 % of water hyacinth, treatment two with 100 % of cow manure and treatment three with 50 % of water hyacinth and 50 % of cow manure. The earthworm used was Eisenia fetida Savigny. Vermicompost was characterized physically, chemically and microbiologically, and measured by indexes of stability and maturity, as well, metal concentrations were detemined. Germination index was obtained with four different seeds: radish (Raphanus sativus L.), lettuce (Lactuca sativa L.), cucumber (Cucumis spp.) and zucchini (Cucurbita pepo L.). The three different treatments for vermicompost were stable and mature after 110 days with 90 % of E. fetida survival in each treatment. The vermicompost with water hyacinth and water hyacinth plus cow manure had a high pH and electrical conductivity. Radish had the best performance in germination index and the three vermicompost were rich in metals. We conclude that vermicomposting is suitable for managing water hyacinth because it can produce a stable, mature, and rich in nutrients vermicompost, which is useful as organic fertilizer or soil improver.