采用蛭石培养试验 ,研究了不同供氮水平对蔬菜硝酸盐累积和分布的影响 结果表明 ,油白菜和大青菜的硝酸盐含量明显高于日本超能菠菜和宁夏圆叶菠菜 ;油白菜、大青菜和宁夏圆叶菠菜体中 ,叶柄的硝酸盐含量最高 ,也是累积硝酸盐的主要分布部位 ,侧根、叶片和叶柄则依次是日本超能菠菜在低、中、高氮水平下硝酸盐含量最高和主要分布部位 ;随供氮水平提高 ,4种蔬菜的主根、侧根、茎、叶柄和叶片的硝酸盐含量明显提高 ,油白菜、大青菜和宁夏圆叶菠菜分布于叶片中的硝酸盐数量增大 ,主根和侧根的数量趋于减小 ,而日本超能菠菜分布于主根和茎的数量逐渐增大 The vermiculite culture experiment was conducted to study the effects of different levels of nitrogen on the accumulation and distribution of nitrate in vegetables. The results showed that the nitrate content in oil cabbage and cabbage was significantly higher than that of Japanese super spinach and ningxia leaf spinach. The highest nitrate content of petioles was also found in green vegetables and the round leaf spinach of Ningxia. Nitrate content was also the main distribution point of nitrate accumulation. The lateral roots, leaves and petioles were the highest in low, medium and high nitrogen levels And the main distribution sites. With the increase of nitrogen supply, the nitrate content of main roots, lateral roots, stems, petioles and leaves of four kinds of vegetables increased obviously. The number of nitrate in leaves of oil cabbage, Chinese cabbage and Ningxia round leaf increased Large, main root and lateral roots tend to reduce the number of Japanese super spinach distribution in the main root and stem the number gradually increased