COINOCULAÇÃO COM BACTÉRIAS FIXADORAS DE NITROGÊNIO JUNTAMENTE COM ADUBAÇÃO NITROGENADO VIA FOLIAR NO CULTIVO DE SOJA

Abstract

The experiment was conducted in a commercial production area in the municipality of Diorama, GO. The experimental design used was a factorial scheme (4 x 2) with a randomized block design, with 4 repetitions for each treatment. Factor A consisted of soybean seed inoculation with (i) Bradyrhizobium japonicum, (ii) Azospirillum brasilense, (iii) co-inoculation with B. japonicum and A. brasilense, and without inoculation (control). The second factor was the application or not of nitrogen (N) via foliar spray at the V4 phenological stage (four trifoliate leaves). The experimental plot consisted of 5 rows of 5.0 m each, spaced 0.45 m apart, totaling 11.25 m². The soybean cultivar used in the experiment was Brasmax BÔNUS IPRO 8579 RSF. The parameters evaluated included the number of nodules per plant, dry mass of nodules, dry mass per nodule, plant height, leaf area index, SPAD chlorophyll index, shoot dry mass, root dry mass, total dry mass, thousand-grain weight, and grain yield at 13% moisture. At the end, the data obtained were subjected to analysis of variance, and if significant, the effects were compared by Tukey's test at a 5% probability. The technique of inoculation and/or co-inoculation of soybean seeds with Bradyrhizobium japonicum and/or Azospirillum brasilense, along with the application of nitrogen via foliar spray, increases the mass and number of nodules on the roots of soybean plants. The processes of inoculation and/or co-inoculation of seeds with Bradyrhizobium japonicum and/or Azospirillum brasilense enhance the growth of the shoot and roots of soybean plants, with positive effects on grain yield.