The effect of form and placement of N on yield and nitrate content of white cabbage

During the period 1995-1997, the effect of three types of nitrogen fertilizer (ammonium nitrate, ammonium sulphate and urea) and two methods of application (broadcast or placement) on the yield and nitrate level of cabbage heads was investigated. N application was 300 kg N ha(-1) in the 0-20 cm layer. The type of fertilizer did not influence the cabbage yield, however, the placement technique did slightly reduce it. The nitrate level in the cabbage heads was correlated with the type of fertilizer and with the method of its application; however, the nitrate content differed in the individual years of the experiment. The greatest decrease in nitrate content in cabbage was found in the placement treatments in 1995 and 1996.