Agronomic performance of maize under nitrogen fertilization and inoculation with Azospirillum brasilense

Given the potential of Azospirillum brasilense as an alternative to improve availability and use of N by maize, it is critical to conduct research in different regions to assess the results of inoculation under several different conditions. The study aimed to analyse the influence of Azospirillum brasilense on the growth and maize yield, as well as its interaction with nitrogen (N) fertilization. The experiment was conducted in two trials (Palotina, PR – trial 1; Ariquemes, RO – trial 2) in Brazil. The experimental design was randomized blocks in a factorial 2x4 arrangement. First factor was application of N fertilization (with or without application), while the second factor consisted of A. brasilense inoculation such as: no inoculation (control), via seed treatment (ST), via leaf application (LA) and ST + LA. The N contents of leaf and the agronomic performance were assessed. Analysis of variance was conducted with the F test (p<0.01). The mean levels of the inoculation factor with A. brasilense were compared via Tukey’s test (p<0.01). The F-test was conclusive in comparing the means of the levels of N application factor. The analysis was conducted by means of orthogonal contrasts to compare the treatment of A. brasilense with those treated with N fertilization. In trial 1, the applying N fertilization associated to A. brasilense via ST and LA may contribute to increase yield. In trial 2, inoculation with A. brasilense seems to be a technology with good prospects for application, contributing to improve production conditions and increase maize yield. Inoculation with A. brasilense is important to supply N to plants, with an increase in agronomic performance of maize. However, inoculation with A. brasilense was not sufficient to meet the demand for N fertilization