Characterization of organic fertlizers produced from aquatic weed, Limnocharis flava (L) Buchenau

Abstract

Aquatic weeds are creating huge ecological and environmental burden to our natural ecosystem. The dense growth of aquatic weeds, especially invasive weeds, are threatening ecological balance through their impact on affecting fresh water availability. Limnocharis flava (L) Buchenau, a monocot weed under the Limnocharitacea family, native to tropical and subtropical America is creating threats in many countries. Bioresource recycling is an integral part of any ecorestoration programme and is highly beneficial in nutrient generation and soil health improvement. For the sustainable management of this aquatic weed, in the present study, L. flava weed collected from a perennial water body was converted into different organic fertilizers viz., ordinary compost, vermicompost, microbial compost using solid inoculum, and liquid inoculum and biochar. The resultant products were subjected to physical (viz., bulk density, water holding capacity) and chemical (viz., pH, EC, cation exchange capacity (CEC), OC, major and micro nutrients) characterization. Recovery percentage was higher for biochar (26.16%) within a temperatuire range of 300-400 °C. Biochar recorded the highest pH, EC, CEC - 9.252, 6.425 dS m-1 and 13.750 cmol (+) kg-1, respectively. N and P content were higher for vermicompost ie., 0.910 and 0.667 %, respectively. Secondary and micronutrient contents were higher for biochar. Hence, it is quite evident that noxious aquatic weed may be utilized as useful organic fertilizer through simple processing. Thus, it offers a sustainable management option for reducing hazards due to aquatic weeds and mitigating climate change.