Inoculação de Azospirillum brasilense na cultura do milho sob diferentes doses de adubação nitrogenada em cobertura

Abstract

Corn crop productivity is strongly related to adequate nitrogen supply. The use of diazotrophic bacteria appears as an alternative to partially supply the demand for this nutrient by plants in order to reduce the use of mineral fertilizers. The objective of the present study was to evaluate the effect of inoculation of Azospirillum brasilense in corn under different doses of nitrogen fertilization in topdressing. The experimental design used was randomized blocks in a 2 x 3 factorial scheme (presence or absence of inoculation and nitrogen coverage doses of 0, 41 kg ha-1 (50% of the recommendation) and 82 kg ha-1 (100% of the recommendation)), totaling 6 treatments and 4 repetitions. The number of viable complete expanded leaves, the average height of plants, the average height of ear insertion and productivity were evaluated. The inoculation of Azospirillum brasilense increased the average height of plants, the average height of ear insertion and corn productivity. Nitrogen fertilization corresponding to 100% of the recommended dose caused the highest values for the variables number of viable expanded leaves complete in R1 and average height of ear insertion, while the maximum productivity estimated by the quadratic polynomial model was 6727.59 kg ha-1 at the nitrogen dose equivalent to 57.8% of the recommended dose.