Production of feed and fertilizer from water Hyacinth plants in the tropics

Abstract

Water hyacinth grows ubiquitously in natural water bodies in the tropics. If allowed to propagate without control, it can cause deterioration of water quality and create problems with water uses. However, water hyacinth has been used for wastewater treatment, and as an animal feed and soil conditioner. This paper reports a case study on silaging and composting of water hyacinth plants generated from ponds treating pig farm wastewater. The water hyacinth plants mixed with molasses and pig manure at the ratios of 85:10:5 (% wet weight) were found to be optimum for silage production; the silaging period was 28 days. The silaged products contained 16% protein and 18% dry matter, suitable for use as animal feed. The composted water hyacinth plants, whose raw materials included pig manure and leaves, contained N, P and K about 2.2, 1.5, and 0.8% (dry weight), respectively. An economic analysis of the two recycling options suggested that some benefits could be gained from these practices after 5 years of operation. These two options were found to be technically and economically feasible to be implemented at farm scale levels.