Azospirillum em milho safrinha solteiro e consorciado com braquiária em solos de cerrado

Abstract

The use of Azospirillum in corn crop is a technology that aims to increase corn productivity with reduced costs with chemical fertilizers. The objective of this study was to evaluate the influence of inoculation and pre-inoculation of Azospirillum brasilense on single off-season corn and intercropped with Brachiaria ruziziensis and its effect on soil microbiological parameters. The experimental design was in randomized blocks, in a factorial scheme 2 (soil textures) x 4 (treatments), with six replications. The locations were Nova Andradina (medium texture) and Vicentina (sandy texture). The treatments consisted of pre-inoculation of Azospirillum brasilense on soybean and inoculation of A. brasilense on single off-season corn and intercropped with brachiaria. The data were subjected to analysis of variance and the means compared by the Tukey test at 5% probability. There was a soil effect for most of the variables evaluated, with higher averages for the medium textured soil. There was an effect of treatments only for height of ear insertion and interaction between soils and treatments for soil microbial biomass carbon, with higher values in the intercropping treatment with pre-inoculation with A. brasilense for medium texture soils. Interaction between soils and treatments for soil organic matter and β-glucosidase, with higher values for the intercropping treatments without inoculation and with pre-inoculation with A. brasilense in medium-textured soil. The use of inoculation and pre-inoculation with Azospirillum brasilense in a sandy textured and medium textured soil did not influence maize yield. Pre-inoculation is efficient in increasing soil microbial biomass in medium-textured soil due to the higher organic matter content. The medium textured soil, due to its higher clay and organic matter content, provides higher productivity of single corn and corn intercropped with brachiaria.