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对不同氮素营养水平下的小麦后移栽棉叶片硝酸还原酶活性、棉株含氮量及叶片氨基酸含量等进行了测定。结果表明，除８月１９日外，叶片硝酸还原酶活性与施氮量呈极显著正相关（ｒ＝０．９６９３～０．９８８１）；地上部各器官的含氮率和绝对含氮量均随施氮量的增加而提高，且不同器官间呈同步增减的趋势，因而氮素分配比例的变化不大；提高氮素营养水平可显著增加小麦后移栽棉的叶片氨基酸总量和游离氨的含量（ｒ＝０．５３１６和０．５６０５），在１７种氨基酸中，谷氨酸、脯氨酸等７种氨基酸的含量与施氮量呈显著的正相关（ｒ＝０．５２５６～０．６０７４）。虽然施氮量越高，棉株的氮素代谢越旺盛，但小麦后移栽棉的适宜施氮量约为２０５ｋｇ／ｈｍ２。
Nitrate reductase activity, nitrogen content in cotton plants and amino acid content in leaves of wheat after transplanting were measured under different nitrogen nutrition levels. The results showed that the nitrate reductase activity of leaves was significantly and positively correlated with nitrogen application rate (r = 0.9693 ~ 0.9881) except for August 19, and the nitrogen and absolute nitrogen contents of various organs in shoots With the increase of nitrogen application rate, and the trend of different organs increasing or decreasing synchronously, the proportion of nitrogen distribution did not change much. Increasing the level of nitrogen nutrition could significantly increase the total amino acid content and free (R = 0.5316 and 0.5605). Among the 17 kinds of amino acids, the content of seven kinds of amino acids such as glutamic acid and proline had a significant positive correlation with the amount of nitrogen application (r = 0.5256 ~ 0.6074). Although the higher the amount of nitrogen application, the more nitrogen metabolism in cotton plants, but the suitable amount of nitrogen for transplanting cotton after wheat was about 205kg / hm2.