MANEJO DA ADUBAÇÃO NITROGENADA E DA INOCULAÇÃO COM Azospirillum brasilense NO RENDIMENTO DE SILAGEM DO CONSÓRCIO MILHO-SOJA

Adubação no consórcio milho e soja

Abstract

Corn-soybean intercrop can increase silage yield, but it depends on nitrogen (N) supply to intercropped crops. This research evaluated the corn-soybean intercrop for silage production, as a function of inoculation with Azospirillum brasilense and nitrogen fertilization management. The inoculation of corn seeds with A. brasilense associated or not with fertilization of N at sowing and topdressing was tested. N supply by inoculation and/or fertilization did not change chlorophyll leaf index and macronutrient and micronutrient leaf contents in corn and soybean plants, except for copper. Intercropped soybean plants have become estiolate, with smaller plant population and lower dry mass compared to sole crop. The dry masses of the morphological components of the intercropped maize plants were similar to that of the sole crop, except for the leaves in the inoculated treatments and cover fertilization until V₄, which were lower. Thus, the lowest silage yields were from soybean sole crop and intercropping with inoculated and fertilized maize plants with 30 kg ha^-1 of N applied in V₄. Inoculation of maize associated with N split in topdressing at doses higher than 30 kg ha^-1 provided silage yield in the intercropping similar to that of corn sole crop. Thus, according to the area equivalence index, regardless of the treatments, the consortium showed no benefits regarding the total silage yield.