The Application of Methanotrophic Bacteria Isolated From Four Rice Centers and Low‐Dosage NPK Fertilizer on the Growth and Production of Rice Plants ( <i>Oryza sativa</i> L.)

A study aimed to determine and investigate the role of methanotrophic bacteria and the dose of NPK fertilizer that has the best effect on the growth and production of rice plants. This research was conducted at the Laboratory of Bioscience and Plant Reproduction Biotechnology, Faculty of Agriculture, Hasanuddin University, and in rice fields. This research was conducted using a separate plot design. The main plot was NPK fertilizer consisting of five different dosage levels, namely, no NPK as a control, 62.5 kg/ha, 125 kg/ha, 187.5 kg/ha, and 250 kg/ha NPK fertilizers. The subplots were methanotrophs consisting of five levels of microbes, namely, no microbes as a control, methanotrophs from Gowa and Sidrap with a concentration of 10 7 CFU/mL, methanotrophs from Maros, and methanotrophs from Pangkep with a concentration of 10 7 CFU/mL. The conclusion of this study is that the interaction between 10 7 CFU/mL methanotroph bacteria from Maros and a dose of 187.5 kg/ha NPK fertilizer gave the best effect on plant height, namely, 75.67 cm/plot. The number of tillers in the treatment of methanotroph bacteria from Gowa and NPK fertilizer of 62.5 kg/ha was 36.38 stems/plot. The weight of 100 grains of methanotrophs from Sidrap was 9.44 g. The production per hectare is 8.53 tonnes. The number of tillers in the treatment of methanotroph bacteria from Gowa and NPK fertilizer of 62.5 kg·ha −1 was 36.38 stems/plot. The weight of 100 grains of methanotrophs from Sidrap and the dose of NPK fertilizer of 62.5 kg/ha was 3.15 g/plot. The recommendation for this study is that the use of methanotrophic bacteria had a good trend to use as biofertilizer in paddy’s cultivation, and it is to investigate the possibilities of these methanotrophic bacteria as an agent to reduce CH4 concentration in the atmosphere.