Adubação nitrogenada e potássica em sorgo granífero de segunda safra no cerrado

Abstract

Top dressing with nitrogen and potassium in a manner appropriate to the requirements of the safrinha crop is favorable to its growth and increase in grain productivity. Thus, the present study aimed to evaluate the response of grain sorghum to the supply of nitrogen and potassium in top dressing. The experiment was conducted in the research area of JL Consultoria, on the Condomínio Agrícola Colibri farm, Uruçuí, PI. The treatments evaluated in the study consisted of different doses of nitrogen and potassium: T1 – 0 kg ha-1 (control, without fertilizer application); T2 - 20 kg ha-1 of N and 13 kg ha-1 of K2O; T3 - 40 kg ha-1 of N and 26 kg ha-1 of K2O; T4 - 60 kg ha-1 of N and 40 kg ha-1 of K2O; and T5 - 80 kg ha-1 of N and 53 kg ha-1 of K2O. The experimental design used was randomized blocks with five replications. The variables analyzed were stem diameter, panicle insertion height, plant height, panicle length, thousand grain weight and grain productivity. The supply of nitrogen + potassium is crucial to improving the productive performance of sorghum in off-season cultivation. The application of a dose of 20 kg ha-1 of N and 13 kg ha-1 K2O proved to be more efficient in increasing grain productivity