Abstract

In the last decades, the Brazilian soy productive chain has passed through a transformation process in which the yield, efficiency, profitability, economic and environmental sustainability are very important issues. In this context, the introduction of microorganisms has provided an increase in grains yield. The objective of this study was to evaluate the inoculation of Azospirillum brasilense associated with Bradyrhizobium japonicum in agronomic traits and the soybean productivity. The experiment was conducted in randomized blocks in 4 × 2 factorial, with four cultivars (Anta 82 RR^®, BRS Favorita RR^®, BRS 780 RR^®, BRS 820 RR^®) and two treatments with A. brasilense (inoculated and non-inoculated) with three replications in two growing seasons. The following traits were evaluated: plant height, shoot dry biomass, chlorophyll content, leaf nitrogen content at flowering; and at harvest, the plant height, the insertion of the first pod, number of pods per plant, number of grains per pod, thousand-grain weight , grain yield, and grain harvest index were evaluated. There was a significant effect of growing seasons and cultivars in an isolated way and their interaction in most traits. The conditions in which the study was conducted, with or without inoculation of A. brasilense associated with B. japonicum do not affect the agronomic traits and grain yield in RR^® soybean cultivars.

Key words: Glycine Max (L.) Merrill, growth promoting bacteria, rhyzobium.