Adubação nitrogenada em pastagens hibernais: uma opção para o suprimento de nitrogênio na cultura do milho em integração lavoura-pecuária

Abstract

The maize cultivated in succession to black oat pasture in winter is a usual practice in southern Brazil. These when fertilized with nitrogen, in crop-livestock integration system, they stand out as an alternative to maximize soil use and animal and vegetal resources. Especially in regard to maize this technique can trigger productivity increases. The purpose of this study was to evaluate the behavior of maize yield components, under different levels of nitrogen in coverage, according to the application of nitrogen fertilizer in the previous black oat crop. The experiment was performed in private rural estate in the years 2013 and 2014, in Abelardo Luz, west of the state of Santa Catarina, near the southwest region of Paran´ a, with the succession of black oat pasture - maize. The experimental design was randomized blocks in a factorial scheme with three replications. The main plot was composed with the nitrogen fertilizer application time factor in coverage: nitrogen applied to the pasture (NP) and nitrogen applied in the grains (NG) and sub-plots N doses (0, 100, 200, and 300 kg ha-1) applied in maize in succession to pasture. It was found that N application on oat and ryegrass had influence on grain yield. The increased production showed the residual effect of this element, as well as the effect of the N applied directly in the culture. The average maize yield was 5541.67 kg ha-1 and 4727.38 kg ha-1 respectively for NP and NG and the parameters differed from each other (P<0.05). The plots which were fertilized with 200 kg ha-1 in winter (NP) did not respond to any of the N levels added in maize (NG). The yield of grains was influenced by the weight of a thousand grains that obtained the the highest average when N application was made in pasture compared to the one performed in maize, 241.11 g and 225.21 g respectively. For the other components that affected the yield, the number of rows responded linearly (P<0.05) to increased nitrogen levels in the sub-plot, and also had higher values in NP. The number of grains per row and number of grains per spike were better presented treatment 200 kg ha-1 NP + 200 kg NG with average values of 33.5 and 609.8 respectively.