摘要
金丝小枣秋季叶施^(15)N-尿素后,研究了氮素在其体内的贮藏部位、形态及循环利用情况。结果表明,幼树秋季叶弛的^(15)N可以输送到树体的各器官,地上部和根系在贮藏氮素上有同等重要的作用,根系可以利用来自叶片的氮供其生长。枣树春季生长先利用地上部贮藏的氮,而叶片回流的氮则优先用于梢、叶、花的形成。成年树分配到花的氮的比例较幼树大。秋季在成年树枣股叶片施用^(15)N-尿素,次年该枣股中的`(15)N量高于其上、下邻近枣股,表现局部贮藏局部优先利用的特点。氮素有较长时期重复利用的效应,重复利用的氮主要来自叶片。
15N-urea was foliar applied on bearing or young jujube tree (Zizyp-hus jujuba Mill.) in autumn of 1987.The effects of leaf-nitrogen retrans-location in the trees,positions of the N stored,forms of reserved N,and reutilization of storage N in the next year were studied.The results were as follows:15N returned and stored in all parts of the tree following foliar application of 15N-urea.Root could use the nitrogen not only absorbed from soil but also transported from leaves.The above-ground organs and roots of jujube tree played the same important roles on nitogen storage in winter.The main forms of storage nitrogen were protein-N,which was 2-3 fold more than non-protein-N.The storage nitrogen existed in above-ground parts was used first in early spring,and that returned from leaves last year could be prior used for the developments of leaves,branchlets and infloresences.The relative distribution of nitrogen in floresence was more in bearing tree than in young tree.In the next year,15N was redistributed in branchlets,leaves,flowers,young fruits and perennial spurs of the trees treated with 15N-urea on leaves of some perennial spurs in autumn.The 15N transported out of the treated spurs reappeared in next spring and further transported to neighboring spurs.The local storage N was prior used for growth.There was 21.49% of fertilizer-N stored in the young jujube trees when treated foliarly with urea in autumn of 1987.After one years's use,there was still 18.91% of fertilizer-N existed in the trees,which indicated a characteristic of circulatory utilization of nitrogen for a long period and the reutilized nitrogen was mainly from jujube leaves and deciduous branchlets.
出处
《核农学报》
CAS
CSCD
1991年第1期37-43,共7页
Journal of Nuclear Agricultural Sciences
基金
国家自然科学基金
关键词
枣树
叶片
氮素
贮藏
循环利用
15N-urea,jujube tree (Zizyphus jujuba Mill.),leaf-nitrogen,storage nitrogen
