Study On The Coupling Of Water And Fertilizer Planting Dwarf Jujube In Hami Based On Isotope

In order to explore the different fertilizer conditions of jujube root distribution, compact coupling effects of water and fertilizer on physiological characteristics of jujube, jujube and soil under different water and fertilizer conditions in the content of N and 15 N isotope abundance variation, the coupling effect of water and fertilizer for jujube close planting dwarf influence. The experiment have been done in the thirteenth Division a star field of two horticultural. Then tested the data analysis results, we came the following conclusions:1. The total nitrogen content in soil decreased with the increasing in depth, the depth at 20 cm above soil total nitrogen content was larger; the greater in depth, the 15 N abundance greater because of the fractionation performance. At 0 cm~60 cm soil depth range, the same amount of fertilizer, the group B,which have the lowest total nitrogen content, have the maximum utilization to N. Shoot and root N content was relatively stable, 15 N abundance changed slightly. Total nitrogen and 15 N abundance in leaf and jujube was larger, it showed the N enrichment in leaves and jujube. When the irrigation quota was appropriate, the absorption and utilization of nitrogen fertilizer was the largest; In the early childbearing N fertilization, the contribution rate is higher at lower crop irrigation quota; partial productivity was lower with the increasing of nitrogen fertilizer.2. Under the same irrigation amount, the shallow soil easily have heat exchange with the outside, the soil temperature was more susceptible to temperature, and the fluctuation range was large, but little effect on deep soil. The larger irrigation amount, the more drops of soil temperature, the maximum temperature at the soil surface,but little change at deep soil. Drip irrigation technique allows that the soil temperature is relatively stable,which conducive to the growth of jujube.3. In the case of a lower amount of fertilizer, the stomatal conductance peak value in lower irrigation quota processing was earlier than large irrigation quota process; but at higher fertilizer amount, the stomatal conductance peak value in larger irrigation quota processing was earlier. Large irrigation quota or higher fertilization treatment is more favorable to maintain leaf’s high transpiration rate. Under the same irrigation quota, photosynthetic rate increases with increasing of the fertilizer amount; and irrigation quota relatively less affected photosynthetic rate,. Under different water and fertilizer conditions, jujube close planting dwarf relations and photosynthetic characteristics, is not a single linear relationship, but coupling relationship.4. In the horizontal direction, the closer the trunk, the more dense root distribution; flood irrigation is more uniform than drip irrigation in root distribution; in the vertical direction, the root distribution relatively dense in the depth of 20 cm~30 cm and 60 cm ~ 80 cm in soil. Lower irrigation quota and appropriate irrigation quota, increasing the amount of fertilizer help to improve yield; excessive irrigation quota increase fertilizer production but reduced. The same amount of fertilizer, the dwarf close planting jujube production, increasing irrigation water contribute to lower yield.