Adubação de sistema em sucessão aveia preta-milho em sistema de plantio direto

Abstract

The system fertilization is characterized by the total or partial application of fertilizer for the crop that will be cultivated in the summer, in the predecessor pasture. Thus, the objective was to evaluate levels of inversion of potassium and nitrogen fertilization in the culture of black oats (Avena strigosa), when used for grazing or cover, on the productivity of corn (Zea mays), subsequent grain culture. The driving took place in the winter of 2016 and in the hot season 2016/2017, in the experimental area of the Federal University of Technology - Paraná, Campus Pato Branco. p. The experiment was conducted in a randomized block design, with split plots and three replications. The evaluated factors consist of fertilization done in winter, in black oat cv Comum, and summer for corn, in which four doses of nitrogen (200; 150; 50; 0 kg ha-1) were used in the form of urea, associated to four doses of potassium (80; 60; 20; 0 kg ha-1) in the form of potassium chloride. The third factor consisted of the presence or absence of cuts in black oats carried out on four dates when the plants reached 0.35 m in height. The results obtained for black oats indicate that the variables total and residual biomass, canopy height, extended tillers length, tiller population density, lodging index, radiation interception, chlorophylls A and total were influenced by the cut for all variables, except for the chlorophyll B content, the failure to perform the cut was higher compared to the plots in which the cut was made. The radiation interception was greater by nitrogen fertilization. Fertilization did not show significant results for oats due to the excellent condition of the soil since the area used is established in the production crop-livestock integrated systems. For corn, the plant stand was influenced by the cut factor and the interaction between the cut factor and the fertilization with N. For the variables number of ears, ear insertion height, plant height and productivity were significant for the cut factor. The stem diameter had a significant effect in relation to fertilization with N. Since fertilization did not have a significant effect for most of the variables evaluated, nor for corn productivity, it can be said that the total or partial inversion of nitrogen and potassium fertilization can be done.