Response of Chinese cabbage grown in the spring season to differentiated forms of nitrogen fertilisation

In the experiment carried out in the Experimental Station belonging to the Wroc aw University of Environmental and Life Sciences in 2004-2006, we estimated the effect of the type of the nitrogen fertiliser (ammonium nitrate, calcium nitrate, ammonium sulfate, urea and ENTEC 26) applied as preplant (150 kg N ha-1) or split dose (100 + 50 kg N ha-1) on the yield and dry matter content, nitrates, vitamin C and P, K, Mg, Ca in ‘Optiko’ Chinese cabbage cultivated during the spring season. The highest total and marketable yield of Chinese cabbage was recorded after the use of urea, which was partly associated with the lowest percentage of diseased heads. Plants fertilised with ammonium sulfate provided the lowest yield. The method of nitrogen application significantly affected the yield and the mean weight of individual heads in the marketable yield, but not the accumulation of nitrates and vitamin C. The lowest accumulation of nitrates was associated with the use of ammonium sulfate and ENTEC 26, whereas the highest with urea. The use of calcium nitrate at a single dose of 150 kg N ha-1 led to the highest accumulation of vitamin C in Chinese cabbage leaves. The levels of P, K, Mg and Ca showed only small changes and were not significantly affected by the type of nitrogen fertiliser or the method of its application.