Absorption and utilization of different applied nitrogen forms by winter jujube
冬枣对不同形态氮素的吸收与利用

With pot experiment, this paper studied the absorption and utilization of applied urea N, Gly N and Glu N by two years old winter jujube. The results showed that all of the three N forms could be absorbed by the winter jujube, but the absorption rate of Gly N and Glu N was less than that of urea N. Taking the absorption rate of urea N as 100% , the relative absorption rate of Gly N and Glu N by jujube leaves was 28. 88% and 11.73%, respectively, and the absorbed N was mainly allocated to the leaves and neonatal branches. Jujube roots could absorb 50. 48% of Gly N and 42. 72% of Glu N. The transaminase activity and soluble protein content in jujube leaves were increased after the application of these three N forms, but the leaf nitrate reductase activity was enhanced significantly by urea N, decreased by Gly N, and less affected by Glu N. Compared with urea N, amino acid N could significantly increase the number of colored fruits and their colored area, as well as the content of fruit soluble solid matter.