Water hyacinth is an aquatic plant favored by gardeners all over the globe. The purple blooms and robust growth have made it so popular, in fact, that infestations in the wild are occurring in locations previously unaffected by the plant. In dealing with the problem, societies are searching for possible uses of the plant to help facilitate its removal from natural environments; fertilizer is one of these uses, and making fertilizer from water hyacinth is proving both effective and easy for many people.
According to the PACE Project (Pan African Conservation Education), water hyacinth is native to South America, where it grows in some abundance. Though thriving in its native homeland, the water hyacinth is also kept in check by natural pests—primarily weevils—which inhibit the plant from excessive growth. Due to the beauty and charm of this aquatic plant, however, many gardening enthusiasts have transported cuttings of water hyacinth all over the world.
In new territories where natural checks do not exist, the water hyacinth is becoming a severe problem. Africa, in particular, has seen devastating waterway damages as a result of water hyacinth infestation, and many efforts are underway to control the spread of this plant.
One of the principle means of control currently is harvesting water hyacinth to make fertilizer. A study in the Journal of Biological Sciences in 2002 revealed that soils amended with water hyacinth actually became more fertile and conducive to agriculture than soils amended with chemical fertilizers.
Water hyacinth is a copious consumer of nutrients, and as it decays those nutrients which it previously absorbed are released back into the soil. However, the primary benefit was in the positive effect the plant had on soil texture. Water hyacinth has distinctive fibrous qualities, and soils amended with water hyacinth fertilizers were more aerated and had superior moisture drainage than their chemically-amended counterparts. These findings are encouraging in the face of so much unwanted, yet prolific water hyacinth growth.
Making fertilizer from the water hyacinth is extremely easy. The aquatic plants have relatively shallow roots, so harvesting them from affected ponds or lakes is simple enough. Once you have harvested as much water hyacinth as you want to use, the PACE Project advises drying for several days. In windy or particularly moist climates, it is recommended that the plants be dried on tarps in a location shielded from the wind; the water hyacinth can grow from cuttings and is robust enough to make its way back to the body of water it came from if basic precautions aren’t taken.
The dried water hyacinth should then be blended at a composting site with ash, manure, and soil. Regular composting practices such as occasional turning and enclosing with chicken wire or (if possible) in a large, seal-able bin should be employed to speed the decomposition of materials. After two or three months a rich, fibrous organic soil will be ready to be tilled into soils for fertilization. The high nutrient content and unique aeration and drainage qualities will greatly enhance crop yields in the amended soils while helping to clear away the ecologically damaging plant from the wild.