Estratégias de adubação em sistema de integração lavoura-pecuária

Abstract

To aim evaluate nitrogen and potassium fertilization inversion on corn crop, instead of summer nutrients could be applied at the beginner of winter, on black oat pasture, eighter under cut or not was carried out. The treatments were four doses of nitrogen fertilization, being 200-0; 150-50; 50-150; 0-200 kg of N, in the winter-summer periods, respectively, four doses of potassium fertilization of 80-0; 60-20; 20-60; 0-80 kg of K, in the winter-summer periods, respectively, and the use or not of plot defoliation. Basic phosphorus fertilization was carried out, both in the implantation of oats and maize, with 35 kg ha-1, in the form of single superphosphate. The experimental design was a randomized block design, with three replications. Each plot measured 21.4 m2, being divided in half, half being used for cover crop and half for forage production. Yield component evaluated were: final plant height; stem basal diameter; final number of plants; height of insertion of the pin; number of ears per ha; number of rows per ear; number of grains per row; tang weight;e diameter; length of spike; thousand grain weight and final yield. There was an increase in the weight of spikes and number of grains per row when a greater amount of potassium and nitrogen fertilization was applied in the winter. In contrast, the weight of a thousand grains was higher when higher doses of N and K were applied in the summer. There was no difference in productivity between the different times of nitrogen and potassium application, and inversion of fertilization was thus possible. Cutting of oat plants also did not influence maize productivity.