Corn agronomic evaluation under different doses of nitrogen and seed inoculation in savanna

The agronomic potential of corn is below the genetic potential of high technology hybrid available in Brazil due to the inadequate management of soil fertility, especially of nitrogen fertilizer, essential photosynthetic activity and determining the crop yield. This study evaluated the agronomic performance and yield of maize culture grown with increasing doses of nitrogen (N), in the absence and presence of Azospirillum brasilense in brazilian Savanna. The design used was the one of randomized blocks in factorial scheme, with five doses of N in corn (0, 50, 100, 150 and 200 kg ha-1), with and without inoculation of the bacterium, with six replications. It analyzed the N content and leaf chlorophyll was measured plant height, stem diameter, insertion spike length and diameter thousand grain weight, grain rot and productivity. The addition of N fertilizers promotes better agronomic performance of maize plants, being this effect greater in the presence of Azospirillum. The productivity of corn respond the dose of 200 kg ha-1 N in the presence of Azospirillum. In 2012/13 crop corn inoculation with Azospirillum brasilense did not cause differences in productivity, plant height, diameter stem, weight of one thousand grains, number of ears and content of chlorophyll A, B and total.   Key words: Fertility, nitrogen fertilization, inoculation, productivity.