Interação entre inoculação com rizóbio e adubação nitrogenada de plantio na produtividade do feijoeiro nas épocas da seca e das águas

This work has the objective of evaluating the effects of the interaction between inoculation with Rhizobium strains and nitrogen fertilization at sowing on common bean ( Phaseolus vulgaris L.) crop. The field experiments with the cultivar Ouro Negro, at dry and rainy seasons, had three treatments: inoculation and sowing N fertilization (20 kg ha-1 of N), only the inoculation, and only sowing N fertilization (20 kg ha-1 of N). Every treatment received 40 kg ha-1 of N by covering. At flowering, the shoot and root dry weight and nodules number and dry weight were evaluated. The higher shoot dry weight was obtained for the inoculation and sowing N fertilization treatment, with similar number and dry weight of nodules of the only inoculation treatment, for both seasons. At the maturity, the higher grain yield, number of pods and grains per plant, were obtained for the inoculation and sowing N fertilization treatment, whereas only inoculation and only sowing N fertilization treatments were not significantly different. Therefore, inoculation can substitute sowing N fertilization with 20 kg ha-1 of N with the same yield. Also, the sowing N fertilization together with inoculation did not inhibit nodulation and improved yield.