Avaliação do desenvolvimento da soja sobre inoculação de fungos micorrízicos arbusculares e bactérias solubilizadoras de fosfato em condições de campo

Abstract

Soybean is one of the most important crops in the world, being responsible for large areas of cultivation, it has a high nutritional requirement, and it is fundamental to search for tools to optimize production. Thus, the objective of this work was to evaluate the development of the use of Arbuscular Mycorrhizal Fungi and phosphorus-solubilizing bacteria in soybean culture. The experiment was carried out at the Bragança farm in the municipality of Lucas do Rio Verde in the state of Mato Grosso, in the 2019/2020 harvest. The experiment followed a randomized block design (DBC) in a factorial scheme (2x2x2) with 4 replications, consisting of 8 treatments, totaling 32 experimental units. The proposed factors were the use of arbuscular mycorrhizal fungi (AMF): 2 (presence and absence), phosphate solubilizing bacteria: 2 (presence and absence) and top dressing phosphate fertilization: (presence and absence). The treatments were arranged in 5x6 m plots composed of 10 planting rows, with 0.5 m spacing between rows, using the soybean cultivar RK8317 IPRO. The association of solubilizing bacteria and arbuscular mycorrhizal fungi with phosphorus fertilization showed an increase in soybean vegetative development. Top dressing phosphate fertilization did not interfere in the vegetative development of the plants, nor did it significantly influence the mycorrhizal colonization. Inoculation of the arbuscular mycorrhizal fungus MF4 provided an increase in root colonization and when the factors were observed together, an increase in productivity could be observed. The inoculation of a phosphate-solubilizing bacterial strain did not result, in isolation, in a significant influence on any of the variables analyzed, but when its effect was analyzed in conjunction with phosphate topdressing, a significant difference in productivity was obtained. Analyzing the unfolding of the interaction, it is noted that in the absence of inoculation with solubilizing bacteria, the phosphorus fertilization contributed to the increase in the number of pods. In the absence of phosphate fertilization, even if not significantly, the solubilizing bacteria provided a greater number of pods per plant. It is observed that, in the presence of phosphorus fertilization, inoculation with bacteria reduced the percentage of colonization of plant roots.