A Review on Harnessing the Invasive Water Hyacinth ( Eichhornia crassipes ) for Use as an Agricultural Soil Amendment

Water hyacinth ( Eichhornia crassipes ) is a globally invasive aquatic weed with high biomass productivity and nutrient content, offering potential as a low-cost organic soil amendment. This review synthesizes findings from 35 studies identified through a structured Web of Science search, examining its use as mulch, compost, biochar, and foliar extract. Reported agronomic benefits include improvements in soil organic carbon, nutrient availability (particularly nitrogen and potassium), microbial activity, and crop yields. However, most studies are short-term and conducted under greenhouse or pot conditions, limiting field-scale generalizability. Additionally, reporting of compost composition and contaminant levels is inconsistent, raising concerns about food safety. While logistical and economic feasibility remain underexplored, emerging evidence suggests that with proper processing, water hyacinth amendments could reduce fertilizer dependence and contribute to circular bioeconomy goals. Future research should prioritize field trials, standardized production protocols, and life cycle assessments to evaluate long-term performance, risks, and climate benefits.