| The loess plateau in northern shaanxi is an area which environmental vulnerability,severe water shortages, and over the last few years fertilization on jujube trees is barbarismbring about lots of problems like the waste of resources, the low yield of jujube trees andthe low economic effectiveness and so on. To investigate and solve these problems, we havestudied the influence of fertilization on the dynamic of physiological property and leafnutrient of the jujube tree in the growth period. These study adopt three elements ofoptimality D saturation design, moisture in the ranking area is set up3modes, which aredrip irrigation in mountain region; soil moisture preservation by covering with straw and themountain soil moisture preserved in fish-scale pit. After one year studying on the dynamiclaw of the physiological property and leaf nutrient, and the yield of jujube trees, we discussthe required of fertilization regular pattern, for the realization of the loess plateau hillymountain red jujube science, precise fertilization, and maximum increase fertilizer useefficiency to provide the theory basis.(1) Research on the dynamic changes of physiological growth of the pear-jujube underdifferent water management measures, we conclude that the amounts of nitrogenfertilizer pear-jujube growth in the early stage of vegetative growth are play animportant role in promoting. And potash can make vegetative growth in fruit expandsthe period promote secondary growth.(2) Through analysising the content of N, P, K nutrient dynamic changes in pear-jujube leafunder three different water management measures, we found that the content of N, P, Kchanges are declining trend with the growth and maturity date fruit in a minimum level,which show that in the date fruit at later growth stage, the need for NPK nutrition for thereasonable fertilizer, to increase the supply of nutrition of trees,and provide improvingproduction nutrient support. N and P coupling obviously, while N and K is not.(3) The content of Ca, Mg dynamic changes in the pear-jujube leaf under different watersaving measures show that, except in the straw mantle, the content of Mg in leaf ishigher than control treatment, other moisture conditions the content of Mg are lowerthan control treatment. Under straw mulch, fertilization is good for the absorption andutilization on Ca, Mg. Under drip irrigation and fish-scale pit conditions, fertilization inhibit the trees absorbing on Ca, Mg.(4) Via analyzing the content dynamic of the micro elements Fe, Mn, Cu, Zn of the leafunder the three water-conservation measures, we conclude that under drip irrigation,there are no obvious difference between fertilization treatments and control treatmentwith the content of micro elements changes. While under straw cover, the content ofmicro elements of fertilization treatments is obviously improved. And much more infish-scale pit. Therefore we conclude that the effect of fertilization to the micro elementsabsorbent has much relationship with the content of water in the soil. When there is notenough water, the more effect of fertilization on the micro element absorbent.(5) The results were obtained through the research of the seasonal dynamics of each mineralelement content in the leaves. Nitrogen-sensitive time was the flowering period andpotassium content changed more obvious in fruit ripening, and potassium-sensitiveperiod was in early September. Due to taking into account the validity of the diagnosticresults to fruit nutritional supplement, it is recommended from the beginning of August.The sensitive time regularity of other nutrition elements was similar to nirtrogen.(6) Via analyzing the effect of fertilization on the yield of jujube trees under the threewater-conservation measures, we conclude that K can give full play to its effectiveness,and significantly improve the yield of jujube tree under drip irrigation. N1P3K3treatment, which reached27448.5kg/ha, has the most significant increase. While underthe un-enough water, just like straw cover and fish-scale pit, the role of nitrogenfertilizer is more prominent. N3P1K3treatment, which reached16396.1kg/ha, has themost significant increase.(7) We established the model on the influence of fertilization on yield under different waterconditions. Use the frequency analysis to find optimization model. The target yield for24000~28000kg/ha under drip irrigation, fertilization scheme respectively as follows: N,246~334kg/ha, P2O5,122~172kg/ha, K2O,147~197kg/ha; under the straw mulch, thetarget yield for the16000~17000kg/ha fertilization scheme respectively as follows: N,250~337kg/ha P2O5,148~192kg/ha, K2O,149~199kg/ha; under mode of fish-scalepits, the target yield for15000~17000kg/ha fertilization scheme respectively as follows:N,262~350kg/ha, P2O5,133~176kg/ha, K2O,121~179kg/ha. |
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