Organic Fertilizer and Water Hyacinth

Organic fertilizers became a hot topic in Sri Lanka after the government imposed a ban on the importation of chemical fertilizers into the country. With this sudden change, farmers were forced to find alternative ways to produce organic fertilizers for their cultivation.

That is when water hyacinth captured the attention of many people in Sri Lanka. Until then, it was known mainly as an aquatic invasive plant. However, once people realized the value of water hyacinth in producing organic fertilizers, the perspective began to change. Today, many people wade into water tanks and lakes to uproot water hyacinth for fertilizer production.

What exactly is water hyacinth?

Water hyacinth, or Eichhornia crassipes, belongs to the family Pontederiaceae. It is a free-floating perennial aquatic plant with broad, thick, glossy, ovate leaves. It reproduces mainly through runners (stolons) and can also produce thousands of seeds each year.

This plant is native to tropical and subtropical South America. It was introduced to Sri Lanka in 1904 for ornamental purposes because of its attractive purple flowers. However, over time, it became highly invasive, spreading rapidly across water bodies and reducing water transparency.

Why is it important in producing organic fertilizers?

For centuries, people prepared fertilizers using natural materials. Over time, with industrialization and agricultural modernization, chemical fertilizers became widely used because they increased crop production efficiently.

However, growing awareness about health and soil sustainability shifted attention back to organic farming. Consumers began to prefer food grown in healthy, chemical-free soil enriched with organic matter, as it is believed to produce better-quality crops.

Why has water hyacinth become one of the best sources for organic fertilizers?

Researchers discovered an important characteristic of water hyacinth: it is an excellent absorber of nutrients such as nitrogen, phosphorus, and potassium (NPK). The water in which it grows is often rich in these nutrients. The plant absorbs and stores them in its stems and leaves.

Because of this high nutrient absorbing capacity, water hyacinth is now used as a valuable biomass source for compost production. Compost made from water hyacinth is nutrient rich and generally pathogen free, helping to improve soil quality.

In addition, this compost releases nutrients slowly over time, improves soil structure, tolerates both acidic and alkaline soil conditions, and supports beneficial microbial activity. These microbes further enhance soil fertility, making water hyacinth an effective and sustainable organic fertilizer source.