Produtividade de milho na presença de doses de N e de inoculação de Herbaspirillum seropedicae

Abstract

The objective of this work was to evaluate the effect of nitrogen and inoculation with Herbaspirullum seropedicae on maize (Zea mays) yield and nutrient contents in grains. The BRS 1030 and BRS 1060 simple hybrids received inoculation with the BR 11417 strain in the presence or absence of nitrogen-fertilizer levels in a Typic Hapladult, during the periods of off-season (sowing in May 2012) and season (sowing in October 2012). In each season, the following treatments were evaluated: absolute control, without nitrogen fertilization or inoculation; inoculated control; doses of 50 and 100 kg ha-1 N, without inoculation; and dose of 50 kg ha-1 N plus inoculation. BRS 1030 produced 1,157 kg ha-1 more grains than BRS 1060, in the joint analysis of both crop seasons. For the first genotype, the dose of 50 kg ha-1 N with inoculation increased crop productivity by 2% in the off-season and by 4.5% in the season. The inoculation with H. seropedicae, BR 11417 strain, favors P accumulation in grains, but it has positive effect on yield only in combination with mineral N levels, which indicates that its effect is more important for maize growth promotion than for biological N fixation.