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为探讨植物根系吸收过程中氮素亏缺与补给及其影响，１９９４～１９９５年，通过沙培盆栽试验，研究了２ａ生杨树、刺槐及两者混植在全营养、缺氮、缺钾和缺磷条件下根、茎、叶中氮素营养的变化特性。结果表明：刺槐根含氮量２％～３％，刺槐茎、叶以及杨树根、茎、叶含氮量均为０．１％～１％，刺槐和杨树的含氮量均按根＞茎＞叶根面土分布。正常营养条件下，混交杨根面土含氮量约等于混交槐根面土含氮量＞纯槐根面土含氮量＞纯杨根面土含氮量。在极度缺乏Ｎ素时，植物生长受到抑制，但与正常植株相比植物的氮素百分含量并不低，杨树中氮素积累量由０．５１ｇ下降到０．０７９ｇ，刺槐中Ｎ素积累量由１．９４ｇ下降到１．２７ｇ。在极度缺乏Ｐ或极度缺乏Ｋ时，植物中氮素积累量受其影响都有不同程度的下降。杨树与刺槐混交，能够改良土壤中氮素的分布状况，提高杨树根、茎、叶中氮素含量，但２ａ生的混交杨在干重方面并不优于纯林杨，在全营养或缺磷条件下混交杨中氮素积累量高于纯林杨。
In order to explore the nitrogen deficiency and supply and its impact during plant root absorption, from 1994 to 1995, we studied the effects of 2a poplar, acacia and mixed planting on the effects of total nutrition, nitrogen deficiency, potassium deficiency, Characteristics of nitrogen nutrition in roots, stems and leaves under phosphorus deficiency. The results showed that the content of nitrogen of Robinia pseudoacacia was 2% ~ 3%, the nitrogen content of stem, leaf and poplar roots, stems and leaves were 0.1% ~ 1%, the nitrogen content of Robinia pseudoacacia and Populus were root> stem Ye Ye root surface soil distribution. Under normal nutrition conditions, the nitrogen content of mixed root is about equal to the nitrogen content of mixed R. pseudoacacia> nitrogen content of pure P. pseudoacacia> nitrogen content of pure root soil. In extreme deficiency of N, plant growth was inhibited, but compared with the normal plant nitrogen content is not low, poplar nitrogen accumulation decreased from 0.51g to 0.079g, N accumulation in black locust From 1.94g down to 1.27g. In extreme lack of P or extreme lack of K, plant nitrogen accumulation affected by its varying degrees of decline. Poplar and locust hybrids can improve the distribution of nitrogen in the soil and improve the nitrogen content in the roots, stems and leaves of poplar, but the hybrid poplar 2a is not superior to the pure poplar in terms of dry weight, The nitrogen accumulation in the mixed poplar was higher than that in the pure poplar.