The potential of plant growth-promoting microbes from South Kalimantan acid sulfate soil in enhancing the growth of rice plants

Rhizobacteria and dark septa endophytic (DSE) fungi isolated from indigenous plant of acid sulfate soil (ASS) in South Kalimantan has potency as an adaptive plant growth promoter. The study aimed to test the effectiveness of the rhizobacteria and DSE in improving swamp rice growth in ASS. Inpara 2 rice variety was used in greenhouse experiment using randomized complete design. Inoculants and compost were applied to the potential ASS-filled pot. The observed parameters were plant height, tillers number, rice straw and root weight, as well as root length. The plant height at 14 and 21 days after transplanting (DAT) was significantly higher in three rhizobacteria treatments over three DSEs and uninoculated treatment. All rhizobacteria significantly increased tiller number, rice straw and root weight, and length compared to control. The DSE GS1-2 significantly improved tiller number, as well as, root weight, and length over control. Rhizobacterium KM19.2 revealed highest effect on rice straw fresh and dry weight, root fresh weight and length. Rhizobacterium PD5.3.1 produced highest plant height at 14, 21, and 56 DAT as well as, tiller number and root dry weight. Therefore, the rhizobacteria and DSE GS1-2 could be used as a promising bio-fertilizer for improving swamp rice growth in ASS.