Rice Straw Composting by Cellulolytic Bacteria Isolate and Its Application on Rice in Acid Sulfate Soils

Abstract

High acidity in acid sulfate soils due to pyrite oxidation results in increased Al3+ and Fe2+ activity which inhibits the growth of rice plants. The application of organic matter (compost) is one of the technology to manage acid sulfate soil. This study aims to obtain cellulolytic bacterial isolates that are superior in composting and improving rice growth in acid sulfate soil. The experiment carries out in the laboratory and glasshouse of the Indonesian Swampland Agriculture Research Institute (ISARI), Banjarbaru, Indonesia on May-November 2017. The experimental to obtain cellulolytic bacteria and water content that can accelerate composting is arranged by factorial using a complete randomized design with three replication First factor were cellulolytic bacteria application (without application/control, BS 1.6, BS 1.9, BS 2.2 and BS 2.5), while the second factor was water content (50%, 100%, and 150%). The effect of compost application with cellulolytic bacterial to rice growth arranged by factorial completely randomized design with 3 replications. The first factor was cellulolytic bacteria application (without application/control, BS 1.6, BS 1.9, and BS 2.2), while the second factor was composting condition (muddy waterlogged and waterlogged 5 cm depth). The result showed that the ability of cellulolytic bacteria to reduce C/N straw was not different. Only differences in water content affect the reducing C/N ratio of straw. The average C/N ratio of straw compost made with 50%, 100%, and 150% water content is 35.59; 29.71, and 29.21. Application of compost made under muddy waterlogged and inoculated BS1.9 and BS2.2 can increase the number of tillers, while those inoculated BS1.6 and BS1.9 can increase the rice shoot dry weight of Inpara 2. The suggest that cellulolytic bacterial inoculation can improve the quality of compost so that the growth of rice is better.