氮素形态对白菜硝酸盐累积和养分吸收的影响

 试验研究表明, 白菜生长适宜营养液的NH^₄+-N 和NO₃^--N (mmol/L) 配比为5∶5, 随着NH^₄+-N比例的增加和收获时期的延迟, 白菜中硝酸盐积累减少, 而游离铵含量增加, NH^₄+-N比例超过75 %时叶片中脯氨酸明显积累, 生长速率下降, 叶片含水率、根长都明显下降, 根系吸收P、K、Ca、Mg 等元素降低,白菜氨害明显。调节适宜的氮素形态比例, 有利于白菜生长和品质提高以及对水分和养分的吸收利用。

Effect of Nitrogen Forms on Nitrate Accumulation and Nutrient Absorption in Cabbage

Response of cabbage to NH^₄+-N and NO₃^--N (mmol/ L) quantity and ratio was studied in solution culture. Ratio of NH^₄+-N to NO₃^--N (mmol/ L) of cabbage suitable growth is 5. 0∶5. 0. The accumulated quantity 2N retained in cabbage decreased , while NO₃^--N quantity increased with the increase of NH^₄+-N rate in nutrition solution was over 75 % , praline content increased in cabbage leaf , growth rate decreased , leave relative water content and root length obviously decreased , the amount of root absorption of P , K, Ca , Mg etc decreased , cabbage obviously suffered from ammonia injury. Regulating suitable nitrogen form proportion in cabbage growth condition would be benefit to cabbage growth and quality , and available utilization and absorption of water and nutrient .