Efeitos da aplicação do herbicida glifosato na microbiota de solo hidromórfico do cerrado

Abstract

The microorganisms in the soil are largely responsible for biogeochemical cycles. For this reason, their survival depends on many environmental factors. The ability to synthesize compounds and degrade harmful substances is large, and for this reason can be used as environmental technologies for decontamination of environments. In flooded soils, the environment is further restricted by the decay of oxygen and so the microorganisms acquire the ability to use other chemicals alternatively soil instead of oxygen as electron acceptors to promote your metabolism. In the presence of pesticides, the development of the microbiota can be affected, sometimes by the toxic action of the organic molecules, either by stimulationg specific groups of organisms. Little is known about the effects of pesticides on microorganisms in hydromorphic soils subject to prolonged flooding and saturation. The aim of this study was to evaluate the effect of glyphosate on soil microorganisms hydromorphic soil of the Cerrado under anoxic conditions. This study was conducted indoor at the Universidade Federal de Goiás (UFG), using hydromorphic soil of the preserved Vereda, of the Cerrado Biome. The samples were collected in the field at a depth of 0-15 cm and received four treatments ( 0 ; 1L/ha ; 12 L / ha and 100 L / ha of glyphosate ) in triplicate . To reach the anoxic and anaerobic incubations was built in biogeochemical reactor inert atmosphere . Daily measurements and measurements of CO2 in five days throughout the incubation period (1, 3, 7 , 15 and 30 days) pH , ORP , microbial biomass and plate counts were performed under inert atmosphere using the reactors and a glove bag . Results showed a trend of first dose of glyphosate ( 1L/ha ) have an inhibitory effect on the microflora and the higher doses ( 12 and 100 L / ha ) a stimulus effect when compared to the control and the first dose .