Microbial community and its relationship with the suppression of nematodes in a crop-livestock integration system

Abstract

The proposition of more sustainable agricultural systems has been a priority for Brazilian agriculture, in view of the exhaustion of the conventional cultivation model, the increase in the costs of chemical inputs and society's search for healthier foods. In this context, biologically-based agriculture has advanced as a model that grows in rural areas and has demanded new scientific studies. In agricultural areas with a predominance of sandy textured soils, low levels of organic matter and a history of monocultures such as pastures and sugar cane, there is a need for studies that seek to assess how new cropping systems can increase agricultural sustainability under these conditions. In this sense, the integration-crop-livestock system, with the cultivation of soybeans in the summer and pastures in the off-season, has gained prominence in recent years as a management strategy that achieves improvements in soil properties, with greater sustainability. However, some phytosanitary challenges have deserved greater care, such as the control of phytonematodes in soybean cultivation, as well as other soil pathogens. The investigation of the microbiome, in sandy textured soils, in crop-livestock integration systems, can reveal important changes in the composition of the microbial community in the soils. This can support new proposals for agricultural management in soybean growing areas, aiming to reduce costs with chemical inputs and increase crop yields, as well as support studies of environmental risks, such as the increase in antibiotic resistance, found in the bacterial community. It is assumed that pastures can harbor a diverse microbial community in their rhizosphere or endophytic form, and in integrated systems this microbiome can interact with other crops, such as soybeans, providing benefits such as the control of phytonematodes. In this sense, this project is justified by the need to generate unprecedented and important results regarding changes in the soil microbiome within the livestock farming integration system, implemented in sandy soils, which can assess agricultural and environmental impacts, by adopting this system. Establishing, in this context, the main objectives: to evaluate the composition, structure and diversity of the microbial community in the rhizosphere of soybean and Brachiaria, in succession in SILP and the potential of nematode suppression. (AU)