Sources and nitrogen rates on sidedress to maize crop in reduced rows spacing

This work seek to verify nitrogen management on sidedress to maize crop in reduced rows spacing. Experimental design was randomized blocks in split-splot scheme with N sources ( urea, ammonium sulfate and ammonium nitrate) in the plots and N rates ( 0, 50, 100 and 150 kg ha(-1)) in the split-splots with four replications in each treatment. The N was sidedressed to plants, at once time, when these were with sixth expanded leaves ( V-6). The increasing of N rates obtained maximum point to grains yield at rates of 60, 106 and 121.2 kg N ha(-1) with urea, ammonium sulfate and ammonium nitrate, respectively. The N sources had no effect on the variables analyzed.