Application of silicate-solubilizing bacteria to reduce biotic stress and optimize rice yield in intensive paddy fields

Abstract

Silica fertilizers remain underutilized in Indonesian rice farming despite the natural abundance of silica from volcanic ash in paddy fields. This is primarily due to the limited bioavailability of silica in rice plants. Silicate-solubilizing bacteria (SSB) offer a promising solution by enhancing silica availability and improving plant resilience. This study, conducted in Sukaresmi Village, Megamendung District, West Java, aimed to evaluate the combined effects of silica fertilizers, NPK fertilizers, and SSB on rice growth, yield, and resistance to biotic stress in Inceptisols. A randomized complete block design with 12 treatments and three replications was used, incorporating various silicate sources—such as straw, empty oil palm bunches, biosilica, RabanaSil, and silica gel—and the bacterium Enterobacter cloacae CmA12 as the SSB. Results showed that integrating silica fertilizers and SSB with NPK significantly improved rice productivity and plant vigour. Although plant height was unaffected, tiller number and overall plant health increased. Notably, yields rose from 4.96 to 8.57 tons per hectare. Biotic stress was also reduced, with a 22% decrease in blast disease, a 23% reduction in pest attacks, and 44% fewer empty panicles. These outcomes suggest SSB can reduce pesticide dependency while enhancing plant resilience and nutrient efficiency. The study highlights the potential of combining silica fertilization and microbial biofertilizers to boost rice production sustainably.