Twin response of increasing doses of nitrogen and nitrogen-fixing organism on agronomical and nutritional parameters of rice

In agriculture, the incorrect use of nitrogen fertilizers have been seen to affect the environment so the use of (N)-fixing bacteria is an alternative for clean production worldwide. We evaluated the effect of increasing doses of N (0, 40, 80, 120 and 160 kg ha−1) and foliar application of Methylobacterium symbioticum (330 g ha−1) during two seasons, on rice grain and straw production, macronutrient concentration and extraction, and on N apparent recovery efficiency (NARE). The results showed that the application of N increased both grain and straw production, with an agronomic response maximized at 120 kg of N ha−1. Increases in grain N and S concentrations were achieved only in the second season with 160 kg N ha−1. In grains, N and S extraction was increased in both seasons, and P, K, Ca and Mg extraction was increased in the second season with 120 kg N ha−1. S concentration and nutrient extraction in the straw were consistently increased with 160 kg ha−1. The application of Methylobacterium allowed to increase Ca concentration in grain (first season), and N and S extractions in grains, and N in the straw (second season). The NARE values ​​obtained in this study fluctuated between 19.2 and 66.6% and were not significantly affected by the application of N or Methylobacterium, however the use of this bacterium presented an additive response on NARE with a quantitative increase from 7.7 to 32.3%, therefore its use is recommended from an environmental perspective together to an N-dose of 120 kg ha−1.