Azospirillum brasilense e adubação nitrogenada na Brachiaria decumbens

Abstract

Livestock grazing activity remains the most widely used technique, feasible and cheap in Brazil, however, the extractive form of livestock is increasing the degraded pasture areas or in the degradation process. Depletion of soil fertility as a result of fertilization, has been touted as one of the main causes of degradation of cultivated pastures. Biological nitrogen fixation in this context can be used as an alternative to increase forage productivity and reduce spending on nitrogen fertilizers. Given the above, the realization of this research was to determine the height of plants, number of tillers, dry matter (MSPA), root dry weight (MSR), chlorophyll content, nitrogen efficiency ratio MSPA / MSR Brachiaria decumbens, nutrient content in the shoot of forage and soil chemical properties due to the nitrogen fertilization associated or not with Azospirillum brasilense. The experiment was conducted in a greenhouse at the Federal University of Grande Dourados, in the municipality of Dourados - MS, using a completely randomized Quartzarenic. The experimental design was completely randomized in a factorial 2x5, with four replications. The treatments were constituted by the combination of two factors: inoculation with Azospirillum brasilense (presence or absence) and nitrogen (0, 50, 100, 150 and 200 kg ha-1). Inoculation of Brachiaria decumbens seeds with Azospirillum brasilense contribute positively in the development and production of forage, with an increase in plant height, number of tillers, dry matter production of the part and root dry matter when combined with nitrogen to the dose 100 kg ha-1 of nitrogen. The Azospirillum brasilense with nitrogen fertilization caused interaction in relation to nutrient content in plant and soil chemical properties. Inoculation with Azospirillum brasiliense generally contribute positively to the nutrition of Brachiaria decumbens.