Produção e concentração de nitrogênio em soja sob doses de Bradyrhizobium japonicum

Abstract

The world’s population and the need for food production are directly proportional parameters that have increased over time. This way, studies of agricultural systems optimization focused on the environment sustainability and higher yield become necessary and important. Soybean (Glycine max) is the most important crop for Brazilian agriculture, with harvest reaching 113 million tons in the country, but for high yield production adequate nitrogen supply is necessary. This nitrogen can be absorbed directly from the soil or supplied by biological nitrogen fixation. The aim of the present study was to evaluate soybean production parameters under inoculant doses. The experiment was carried out in Rio Brilhante city in a randomized block design with five treatments; zero, one, two, four and eight inoculant doses applied with CO2 costal spray in seeding furrow. The used variety was the M6410ipro, from Monsoy, evaluated in the eighth vegetative stage, where the soybean presents 7 fully expanded leaves, and in the first reproductive stage, where 50% of the plants have flower. Were evaluated for fresh and dry mass of aerial part, Roots and nodules, number of nodules, leaf nitrogen concentration, the height of plants, plants per meter, pod per plant, branching per plant, weight of one thousand grains and productivity were evaluated. Nitrogen fixation by bacteria in the root nodules was not efficient in the presence of mineral nitrogen applied in the sowing furrow.