Utilization potential of rice husk biomass (Oryza sativa l.) var. Inpari 32 for renewable alternative energy in the agricultural area of Tuban, East Java

Rice husk, a lignocellulosic byproduct of rice cultivation, represents a promising biomass resource for renewable energy systems and sustainable agricultural practices. This study investigates the physicochemical properties and utilization potential of rice husk derived from the Inpari 32 rice variety cultivated in Jenu and Palang Districts, Tuban Regency, Indonesia. Proximate analysis indicates a stable fixed carbon content of 44- 45% and a calorific value ranging from 4,365 to 4,847 Kcal/kg, confirming its suitability for co-firing in thermochemical energy conversion processes. Biomass productivity assessments reveal an average dry husk yield of 5- 7 g per plant, supporting its feasibility for energy recovery at scale. Environmental conditions further influence rice husk quality. Jenu District exhibits near-neutral soil pH (6.14) and high organic carbon content (4.43%), resulting in improved carbon stability. In contrast, Palang District has more acidic soil (pH 5.64) with elevated phosphorus (120.2 mg/100g) and potassium (185 mg/100g) levels, making its rice husk more suitable as a soil amendment. These findings demonstrate the dual functionality of rice husk from the Inpari 32 cultivar: as a renewable solid fuel and as an organic soil enhancer, thereby contributing to integrated energy-agriculture sustainability strategies in rural Indonesia.