Chemical soil attributes under N fertilization and A. brasilense

We aimed to investigate the effect of inoculation with A. brasilense in conjunction with varying N doses and sources in a Cerrado soil on soil chemical attributes of irrigated wheat production. The experiment was initiated in Selvíria - MS under no-tillage production in an Oxisol in 2014. The experimental design was a randomized block design with four replications and treatments were arranged in a 2 x 5 x 2 factorial arrangement as follows: two N sources (urea and Super N - urea with inhibitor of the enzyme urease NBPT (N - (n-butyl thiophosphoric triamide))) five N rates (0 50 100 150 and 200 kg ha-1) and with or without seed inoculation with A. brasilense. The increase in N rates did not influence the chemical soil attributes. Super N acidified the soil more compared to urea. A. brasilense inoculation reduced the effect of soil acidification in intensive irrigated wheat cultivation; however the base extraction was higher resulting in a lower soil CEC after cultivation with inoculation. Therefore the cultivation of wheat inoculated with A. brasilense was not harmful to soil fertility because it did not reduce the base saturation and organic matter content.