Aplicação foliar de Azospirillum brasiliense em milho associado com níveis de nitrogênio

Abstract

Corn has major social and economic importance to Brazil and is influenced by environmental stress problems, among which mainly highlights the low fertility of the soil, that, mostly, show deficiency of N. To achieve maximum yield in cereal crops, such as corn, it is necessary the application of high doses of fertilizers, especially nitrogen. However, in recent years, it was possible the finding new sources such as diazotrophic microaerobic bacteria, the Azospirillum genus, that promote the fixation of atmospheric nitrogen, when in free living, and, when associated with the rhizosphere of plants they can contribute to the process of fixing and thus reduce nitrogen rates required. This study was carried out to evaluate the performance of corn due to the application of different rates of nitrogen combined to doses of leaf inoculant aiming high yields. The experimental design was a randomized block with four replications and treatments were arranged in a factorial 3 x 4 , corresponding to three doses of inoculant , at a concentration of 0 , 100 and 200 ml ha-1, and four doses of nitrogen , 0 , 60, 120 and 180 kg N ha-1 applied on V4 -V8 stage using urea as a source . The cultivar used was the hybrid DKB 290 VT PRO 3® . There was no interaction between doses of inoculant x nitrogen doses for any of the response variables . The inoculant affected , quadratically, the nitrogen content in the ear. In turn, the increasing levels of nitrogen linearly increased nitrogen content in the leaf and the yield of corn grain.