Abstract

Cowpea is considered as one of the most important species in Brazil, for presenting essential components to the feeding process, which makes it relevant to identify the physical, chemical and biological conditions that benefit or cause damage to its development. Thus, the objective of this study was to evaluate the effect of inoculation with rhizobia strains in compacted soil on the development and production of cowpea. The experiment was conducted in a greenhouse, in a completely randomized design with six replications, in a factorial 3 × 2, with two inoculation treatments (BR3267 - Bradyrhizobium sp. and the combination of the strains MT8 - Rhizobium tropici and MT15 - R. tropici) and a control with nitrogen fertilization - 150 mg dm-3, using urea as a source, in compacted and uncompacted soil. The evaluations were carried out during the crop cycle (35, 45, 52, 58 and 90 days) after the emergence of plants, determining the Falker chlorophyll content, dry mass of grains, nitrogen content, nitrogen accumulation and crude protein in shoots and grains. All data were subjected to statistical analyses using the SISVAR program, performing the analysis of variance and the Tukey test at the level of 5% probability. The results showed positive effect on plants inoculated with the combination of the strains MT8 + MT15 in compacted soil, in all parameters evaluated, being observed, values similar to or greater than in plants grown in uncompacted soil. Therefore, the use of the combination of strains becomes a promising alternative for the cowpea development in soil with a density of 1.6 Mg m-3.

Key words: Biological nitrogen fixation, cerrado, soil density.