Study On Effects Of Fertilizer On Jujube In Loess Hilly Region Under Different Saving Water Measures

Northern Shanxi Province is one of the important production areas, water and fertilizer are the key elements of influenting jujube yield and quality, necessary experiment is shortage because of extensive management. Experiment used split plot design, Maintreatment is set up 3 saving water measures, which are drip irrigation in mountain region; soil moisture preservation by covering with straw and the mountain soil moisture preserved in fish-scale pit. Sub-treatment is set up 10 fertilizer treatments, which adopt three elements of optimality D saturation design, Three nutritional elements are included in handling fertilizing, namely N, P and K. After studying the relationship of the fertilizer efficiency, the yields of jujube and the quality of fruits under different measures of drip irrigation in mountain region, soil moisture by straw cover and mountain preserving soil moisture in fish-scale pit, we can see the results show:(1) In the three saving water measures, K3 is better for the growth rate of new shoots.In the drip irrigation,soil moisture preservation by covering with straw and the mountain soil moisture preserved in fish-scale pit, the growth rate of new shoots of the jujube is 14.17cm,11.88cm,9.6cm respectively. N3P3K1 is better for promoting the chlorophyll content, the chlorophyll content of the jujube is 26.55mg/g,18.10 mg/g,20.21mg/g respectively. N3P3K1 is better for diameter expanding, diameters expanding are1.4cm,0.86cm,0.26cm respectively. In elongate shoots period,fruiting stage,fruit expanding process and maturity period, leaf areas first increase then decrease and increase then decrease.K3 is better for the fruit-bearing rate of the jujube, the fruit-bearing rates of the jujube are 12.8%,9.69%,6.29% respectively. N1P3K3 is better for the yield of the jujube, the yields are 21216.9kg/hm²,17279.16 kg/hm²,14330.42kg/hm² respectively, Corresponding soil moisture contents are 16.02%,9.59%,8.44%. Soil average moisture contents are 11.08%,8.37%,7.98% kg/hm² respectively.(2) Analized total acid content of jujube, in the three saving water measures, compared to the control treatment,total acid contents of other different fertilization treatments are more higher.In drip irrigation condition, total acid content of N3P1K3 is the most highest, which is 0.895%, in covering with straw, total acid content of N3 is the most highest,which is 0.851%,in fish-scale pit, total acid content of K3 is the most highest,which is 1.09%.Analized Vc content of jujube, in the different saving water measures, the ordering of Vc contents of different fertilization treatments is not unanimous completely.Analized protein content of jujube, fertilizering N can improve protein content significantly. Analized the content of Soluble Soilds, in drip irrigation condition, soluble soilds content of other treatments is lower than control treatment besides N1P3K3 and N3P3K1,in the condition,fertilizering is not better for promoting content of soluble soilds.In covering with straw,fertilizering N is better for promoting soluble soilds content,just the opposite for P, in drip irrigation condition,fruit hardness of the other fertilization treatments is harder than control treatment besides N2P2 and N3P1K3. In covering with straw,different fertilization treatments can decreased fruit hardness, in fish-scale pit, N,K,P Ratios application is better for decreasing the fruit hardness,but it is not better for the fruit storage.(3) Under the same saving water measure, different fertilization treatments can increased soil nutrient content, and the contents of organic matter,total N,available P and available K first decreased and then increased in the 0-20cm,21-40cm and 41-60cm soil depth. The nutrient content of 21-40cm soil depth is shortage,the cause is that root mainly allocated 41-60cm deep layer in soil,the appalication of saving water meatures is better for absorbing the nutrient of the upper soil layer. In the three saving water measures,compared the nutrient content of 0-20cm soil depth in different moisture,we can see the contents of organic matter under the conditions of straw mulching is higher than the contents of the other two saving water conditions. Compared the nutrient content of 21-40cm soil depth in different moisture, the contents of total N,Available P and Available K under the conditions of drip irrigation is higher than the contents of the other two moisture conditions. The nutrient content change of 41-60cm soil depth in different moisture is similar to 41-60cm soil depth.(4)Established mathematical regression model of different fertilization applying for jujube yields under different saving water measures, and received the optimum N,P,K fertilization for jujube yield under different saving water conditions, Under the mountain drip irrigation, the optimum rates of N,P,K fertilizer is N: 331.372 kg/hm²,P2O5:450kg/hm², K₂O:500 kg/hm²; Under the straw mulch condition, the optimum rates of N,P,K fertilizer is N: 255.868kg/hm², P₂O₅:450kg/hm², K₂O: 500kg/hm²; Under the mountain pit scale, the optimum rates of N,P,K fertilizer is N: 139.161 kg/hm², P₂O₅: 450 kg/hm², K₂O: 452.544 kg/hm².