Sources and Rates of Nitrogen Associated with Application of Azospirillum Brasilense No Season Maize.

Among the factors that contributed to increase in productivity no season maize (Zea mays L.) in Brazil, it were highlight the use of technology in crop management. Nitrogen (N) fertilization is essential for achieving high yields of corn, since N is a nutrient required in large amounts in cycle of maize. Among N fertilizers, urea stands out due to its high concentration of N and provide best value for money, however, the application in soil is subject to high losses by ammonia volatilization. Thus, the use of urea coated with polymers associated with inoculation of N fixing microorganisms such as A. brasilense can maximize the efficiency of N fertilization on corn yield. The aimed of this study was to evaluate the efficiency of foliar application of A. brasilense associated with sources and rates of nitrogen in productivity of out-of-season maize. Experiment was conducted in Vitoria Brasil, SP, Brazil (20° 11' 45" S  50° 29' 42" E and 472 m) from March to June 2013. Experimental design was randomized blocks (2 x 2 x 4 factorial) with four replications. Treatments were: sources of N (conventional urea and coated urea); A. brasilense (with and without foliar inoculation) and N rates (0, 27, 54 and 81 kg ha^-1). There were evaluated: plant height, height of ear insertion, stem diameter, weight of one hundred grains and productivity. Foliar inoculation with A. brasilense and N sources had no influenced on the all parameters evaluated. However, the interactions: N sources and N rates, inoculation and N sources and inoculation and N rates, were significant for yield components, highlighting the combination conventional urea plus 54 kg ha^-1, which promoted the highest productivity (5400 kg ha^-1). Foliar application of A. brasilense associated with or not the N sources and N rates not provided increases in corn produtictivity.