Abstract. The highest nitrate content in cabbage fertilized with N-NO₃ form was observed. The fertilization with (NH₄)₂SO₄ caused an increase of free amino acid content in cabbage leaves but did not affect the level of thiocyanates. The urea application had the most advantageous effect on soluble sugars in red cabbage heads.

The content of some compounds of red cabbage as related
to different forms of nutritive nitrogen

Summary

Red cabbage ‘Langendijker’ was grown in field conditions in 2003-2005. Different forms of nutrient nitrogen such as nitrate nitrogen Ca(NO₃)₂, ammonium nitrogen (NH₄)₂SO₄, nitrate and ammonium nitrogen NH₄NO₃ and amide nitrogen (NH₂)₂CO were applied. In the control treatment the natural soil nitrogen was the only source of N. The lowest and the highest level of nitrates in cabbage heads was found in control and in N-NO₃ treatment, respectively. The fertilization with (NH₄)₂SO₄ caused an increase of free amino acid content in cabbage but did not affect the level of thiocyanates. The urea application caused significant increase of soluble sugars in cabbage leaves. No distinct changes of dry matter content were observed.