The present invention relates to methods of reducing chemical fertilizer usage and greenhouse gas nitrous oxide emission and to methods of improving plant growth rate and seed productivity in agriculture through the application of a novel artificially manufactured formula containing a nitrogen-fixing bacterium that efficiently colonizes non-legume plants in aerial parts and the root system. The bacteria inocula and methods are particularly suitable for plants in the genera Jatropha, Sorghum, Gossypium, Elaeis, Ricinus, Oryza and Manihot.