Coinoculation with Growth-Promoting Bacteria Increases the Efficiency of Nitrogen Use by Irrigated Rice

Considering the importance of rice (Oryza sativa L.) for global food and its significant production in Brazil, strategies for its sustainable production are focused on technologies to increase productivity and decrease the use of chemical nitrogen fertilizers. An alternative for this is the use of plant growth-promoting bacteria that have proven to be efficient for increasing production and nutrient promotion in cereals. This study reports the use of coinoculation with Azospirillum brasilense and Pseudomonas fluorescens to inoculate irrigated rice through seed treatment (ST) with inoculant and seed inoculation in planting furrow technology (PFT) in four field experiments. The inoculation technologies increased rice yields in the presence of A. brasilense + P. fluorescens and with a reduction in mineral N (30 kg of N ha^-1), equal to or greater when nitrogen fertilizer was present alone. Our results demonstrate that coinoculation with A. brasilense (strain Ab-V6) and P. fluorescens (strain CCTB03) increases the efficiency of N use from a mineral source in irrigated rice, with an increase of 37% in economic production (grains per unit of N applied), providing better agronomic performance of the crop.