APLIKASI PARAKUAT PADA TANAH SULFAT MASAM: Pengaruhnya TerhadapMikroorganisme Rizosfer dan Pertumbuhan Padi (Oryza sativa L. �IR 64�)

The current research was aimed to study the effect of the paraquat applicatoin on the rhizosphere microorganism community playing roles in ammonification, nitrification, and P solubilizer in acid sulfate soils and on the growth of rice. The persistence of paraquat in the acid sulfate soils was also analyzed to know the relationship between the paraquat residue and its impact on the non-target organisms. The research used factorial Completely Randomized Design, being the first factor was paraquat dosages: 0 (0 ppm) as control, 1 time (8 ppm) and 10 times (80 ppm). The second factor was rice plants: with planted rice (P1) and without planted rice (P0), each with 3 replicates. The treatment groups of microorganisms and the paraquat residues were calculated periodically, and the result was analyzed using Anova and Duncan�s post-hoc multiple range test. The vegetative rice plant growth was analyzed descriptively. Result showed that the application of paraquat at 8 ppm and 80 ppm on acid sulfate soils did not significantly affect the microorganism groups playing roles in ammonification, nitrification, and nitratation. On the other hand, the significant effect was shown in the phosphate solubilizer groups (P