NITROGEN AND POTASSIUM FERTILIZATION RESPONSE IN Brachiaria brizantha PASTURE WITH CORN INTERCROPPING

The objective of this study was to evaluate the effects of nitrogen and potassium fertilization in corn intercropped (DOW657 and AG2040) and Brachiaria brizantha cv. Vitoria upon production of intercropped species and the pasture formation. Two field experiments were conducted, in which the cv. Vitoria was intercropped with corn in a substitutive design (EXP1), sowed at the corn reproductive period; and in the other experiment the forage seeding was made as the same time as the corn's (EXP2). The EXP1 was conducted in a ramdonmized blocks four replications, arranjed in a factorial scheme 2x5+2. The first factor was the nitrogen doses (30+90+0 and 30+90+30 kg ha(-1) of N), and the second factor was the potassium doses (25+25+0; 50+0+0; 50+25+0; 50+50+0 and 50+25+25 kg ha(-1) of K2O), all distributed along the seed line, in top dressing fertilization (4-6 expanded corn leave) and in the harvest, respectively. In the EXP2 the same design was adopted, but in a 2x5+3 factorial scheme, wich corresponded to the N and K fertilizations, similar to the EXP1, plus the corn monocultives and the fertilized and non-fertilized cv. Vitoria. There were no significant effects of the fertilizer applications in the variables analyzed in the intercropped corn, independent of the forage seeding. Despite that, in the simultaneous seeding, the corn held the growth of the pasture. Bigger doses and applications of fertilizers in cv. Vitoria intercropped increased the forage yield, independent of the seeding period.