Wild-growing lotus plants in swampy marshes and rice production waste in the form of husks are potential resources for use as soil amendments through biochar and compost tea. Therefore, this research aimed to evaluate the potential of compost tea and biochar from rice husks and lotus plants based on physical and chemical characteristics as soil amendments. The treatments experimented for compost tea included the composition ratios of 1:20 (w/v), 1:10 (w/v), and 1:5 (w/v) of rice husks or lotus compost with water. For the analysis, compost tea was made from mature compost extracted aerobically with the tested composition ratios. Biochar from lotus plants (L) and rice husks (S) was produced using a furnace method with a burning duration of 2 hours at a temperature of 200°C, followed by determination of functional group through FTIR and SEM-EDS approaches. The laboratory-scale testing results showed that pH values of lotus and husks compost tea were considered neutral, while lotus biochar tended to be higher compared to husks biochar. Furthermore, it was discovered that concentration of humic substances and nutrients produced increased with a high compost tea solution. Functional group testing using FTIR on biochar detected carbonyl, various aromatic, as well as Si-O-Si and Si-O in rice husks biochar. In lotus biochar, carbonyl, phenolic, lignin, holocellulose, as well as C-O and C-C functional groups were found at different wavelengths. Based on SEM-EDS results, the pores in rice husks biochar were smoother and more abundant compared to lotus biochar, which appeared larger. However, higher concentrations of essential micro-nutrients were found in lotus biochar.

Index Terms- Biochar, compost tea, soil conditioner, organic material characterization