Response of the common bean to nitrogen application at sowing and topdressing in non-tillage systems

Nitrogen fertilization management in non-tillage systems is very important, and the response to its application depends on the applied nitrogen rate as well as the time of application. The objective of this work was to determine the responses of bean crops to different nitrogen dosages and application methods in non-tillage. Treatments were carried out as follows: T1 = 0; T2 = 20 + 30; T3 = 40 + 60; T4 = 60 + 90; T5 = 80 + 120 e T6 = 100 kg ha(-1) of N. Nitrogen application in T6 was done during sowing. In the other treatments, except T1, part of the N (urea) was applied during sowing and the other part at coverage, during the V-4 stage. The randomized blocks experimental design was applied. N, P, K, Ca, Mg, Cu, Zn and Mn production components, leaf area index, dry matter of leaves, final population and foliar content were evaluated. Significant differences were found among leaf dry matter content, leaf area index, number of pods per plant, yield and foliar content for N, P, Ca, Mg and Cu. However, final population, number of grains per pod, hundred grain mass, as well as K, Zn and Mn foliar content showed no significant differences.