CHANGES IN THE BACTERIAL COMMUNITY OF THE SOIL AND RHIZOSPHERE OF SOYBEAN DUE TO THE CULTIVATION SYSTEM AND INOCULATION OF BACILLUS SUBTILIS

Abstract

The proposition of more sustainable agricultural systems has been a priority for Brazilian agriculture, in view of the exhaustion of the conventional model of cultivation and also due to the increase in the cost of chemical inputs. In this sense, the crop-livestock integration system, with the cultivation of soybeans in the summer and pastures in the off-season, has achieved prominence in recent years as a management strategy that achieves improvements in soil properties, with greater sustainability. However, some ecological challenges have deserved greater care, such as the functioning of the soil microbiome and the impacts of the introduction of rhizobacteria by inoculants. The investigation of the microbiome, in soils with sandy texture, in different cultivation systems, can reveal important changes in the composition of the microbial community in the soils. This can support new propositions for agricultural management in soybean growing areas, aiming at reducing costs with chemical inputs and increasing crop yields. It is assumed that pastures can harbor a diverse microbial community in their rhizosphere or in an endophytic form, and in integrated systems this microbiome can interact with other crops, such as soybeans. As it has also been proposed the introduction of new rhizobacteria, by inoculants, but ecological studies related to this practice are still scarce. In this sense, this project is justified by the need to generate unprecedented and important results regarding changes in the microbiome in the soil and rhizosphere within different cultivation systems, implanted in sandy soils, due to the introduction of a selected strain of B. subtilis in the ground. It is in this context that the present study will aim to investigate the structure and functional profile of the bacterial community in soil and rhizosphere after the introduction of a strain of B. subtilis and its effects on soil attributes and soybean yield in crop integration systems livestock and direct planting.