Assessment of compost quality in agitated pile composting of water hyacinth collected from different sources

Background Water hyacinth (Eichhornia crassipes) cancause a diversity of problems due to its fast spread and congestedgrowth. The composting of water hyacinth can reducethe chemical fertilizer application to the agricultural field andproblems related to its fast growth rate and also help in nutrientrecycling. The present study was carried out on agitated pilecomposting of water hyacinth collected from four differentareas (Bharalu River, Agriculture site, Boragaon landfill siteand Industrial site). The nutrients and stability parameterswere evaluated during the 30 days of agitated pile compostingof water hyacinthmixed with cattle manure and sawdust. Thestability of compost was evaluated using respiration techniques(CO2 evolution and oxygen uptake rate).Results Results showed that nutrients (Na, K, Ca, total nitrogenand phosphorus) were increased significantly in allagitated pile composting. Stability parameters such as CO2evolution rate and oxygen uptake rate, biochemical chemicaloxygen demand and chemical oxygen demand were reducedsignificantly during the process. Highest reduction of moisturecontent (35.2 %), volatile solid (40.5 %), ammonical nitrogen(75.6 %), biochemical oxygen demand (65.3 %), CO2 evolutionrate (78.7 %), and oxygen uptake rate (74.4 %) were observedin the agitated pile of Bharalu River site as compared toother agitated piles. The higher increase of total nitrogen(83.5 %) and total phosphorus (76.0 %) was also observed inthe agitated pile of Bharalu River site.Conclusion Addition of optimum amount of cattle manurewas highly efficient for making compost of waterhyacinth collected from four different sites. Highest contentof nutrients was found in compost of water hyacinthcollected from Bharalu River site due to availability ofnutrients in sewage water. In the final compost of all trials,total coliform and fecal coliform were reduced significantly,which are pathogen indicators in the compost.The best compost quality was found in water hyacinthcollected from Bharalu River site.