Coinoculação de Azospirillum brasilense e Bradyrhizobium via sementes de soja no cerrado

Abstract

It is known the efficiency of the use of Bradyrhizobium in biological nitrogen fixation (BNF), supplying a significant part of soybean demand for the nutrient. Another bacterium that is being tested is Azospirillum, which stimulates growth and helps FBN. The objective of this work was to evaluate the co-inoculation of different Bradyrhizobium and Azospirillum brasilense seeds via the seeds on the agronomic characteristics of soybean in the first year of cultivation with the cerrado crop. The experiment was conducted at UFU, Monte Carmelo campus, MG. In a 3x4 factorial arrangement, involving doses via Bradyrhizobium seeds (0; 1,5 x 106 e 3,0 x 106 viable cells per seed) and Azospirillum brasilense (00; 0,6 x 105 ; 1,2 x 105 e 1,8 x 105 viable cells per seed). No chemical seed treatment was used. It was evaluated the height of plants at 30 days after emergence (DAE), height of insertion of the first pod, final height, number of pods per plant, number of seeds per pod and grain yield (kg ha-1 ). The highest dose of Bradyrhizobium provided gains in height at 30 DAE, final height, number of grains per pod and soybean yield. Co-inoculation using A. brasilense and Bradyrhizobium bacteria, both inoculated via seeds, did not favor increases in agronomic characteristics and soybean yield.