Synergistic Effects of Water Hyacinth Biochar and Fly Ash-Enriched Panchagavya as a Sustainable Soil Amendment for Water-Stressed Regions

Environmental challenges demand sustainable agricultural solutions. This study synthesizes nutrient-enriched biochar from invasive water hyacinth (WH) at pyrolysis temperatures (300–700°C) and integrates it with fly ash-enriched panchagavya for soil amendment in water-stressed ecosystems. WH-derived biochar (WHBC) was characterized using SEM-EDAX, XRD, and FTIR, which revealed that WHBC-400°C was optimal, exhibiting a 128% larger surface area (42.7 m2/g) and 40% higher porosity than other variants, thereby enhancing water/nutrient retention. XRD/FTIR confirmed stable carbon sequestration and mineral retention. Soil amendment with 5% WHBC-400°C + 1% fly ash-enriched panchagavya significantly improved water retention (32% increase), nutrient-use efficiency (28% increase), and crop biomass yield (22% increase) under reduced irrigation (60% of conventional requirements). The treatment concurrently reduced synthetic fertilizer dependency by 35% and eliminated the risk of weed reinfestation. This strategy directly supports UN Sustainable Development Goals: SDG 2 (zero hunger) through enhanced soil fertility, SDG 6 (clean water) via optimized irrigation efficiency, and SDG 12 (responsible consumption) by valorizing waste biomass.