Sistemas e manejos agrícolas modulam componentes multitróficos no solo

Abstract

Soil microbiome and relationships with soil meiofauna are important for the stability and functionality of agroecosystems, including their potential effects on soil suppressiveness. However, little is know about how farming systems and alternative methods for controlling plant pathogens determine microbial community, soil meiofauna and plant productivity. In this study, we assessed the composition of soil microbiome (bacterial, fungal and protist) using a high-throughput sequencing approach (16S and 18S ribosomal markers), the population of parasitic and free-living nematodes, the plant productivity and its interrelationships in a long-term experiment dividing conventional and organic systems into alternative methods for plant pathogen control. Conventional and organic farming systems had major influence on soil microbial community, meiofauna and plant productivity, while the effects of the soil health treatments were of smaller magnitude. Organically managed system increased taxonomic and phylogenetic diversity of the bacteria and fungal communities compared with conventional farming system, while no effects were observed on protist community. Organic farming increase the population of free-living nematodes and conventional increase the population of parasitic nematodes and plant productivity. Microbial diversity and community structure appear to be related with parasitic nematode suppression in system receiving organic fertilizer and certain soil health treatments, which were characterized by component microbial groups known to be involved in suppression of soil pathogens. Understand the soil microbiome and multitrophic interactions in agroecosystems offer a potential for managing the soil environment from ecology towards a more sustainable control of plant pathogens using beneficial microorganisms.