Abstract:

To evaluate changes of soil nitrogen component and content of winter rapeseed in different growth periods, winter rapeseed varieties were planted under field growth condition, contents of total nitrogen, ammonium nitrogen, nitrate nitrogen, alkali-hydrolyzed nitrogen, mineralized nitrogen, acid-hydrolyzed nitrogen, amino sugar nitrogen, amino acid nitrogen, non-acid-hydrolyzed nitrogen and unknown nitrogen were tested. The results showed that the content of total nitrogen, acid-dissociated nitrogen and unknown nitrogen in perish period were the highest, 1.24 g/kg, 694.52 mg/kg and 539.50 mg/kg, respectively. The content of nitrate nitrogen at seedling stage was the highest, 33.04 mg/kg. The content of alkali-hydrolyzed nitrogen and ammonium nitrogen were the highest at the turning green stage, 40.68 mg/kg and 21.55 mg/kg, respectively. The content of mineralized nitrogen and amino acid nitrogen were the highest at harvesting stage, 1583.25 mg/kg and 63.45 mg/kg, respectively. The content of nitrogen in perish and turning green stage were significantly different from that at seedling and flowering stage. The “up-down” trend of content of total nitrogen, ammonium nitrogen and non-acidic nitrogen was observed in winter rapeseed during different growth periods, the “down-up” trend was showed in the content of nitrate nitrogen and amino acid nitrogen, the “down-up-down” trend was found in the content of alkali-hydrolyzed nitrogen and aminoglycosaccharide nitrogen, and the “up-down-up” trend was observed in the content of mineralized nitrogen, acidolysis nitrogen and unknown nitrogen.

Key words: winter rapeseed, growth period, nitrogen component, nitrogen content, change