Study On Effect Of Fertilization On Jujube Growth And Yield In Northern Shannxi Under Different Water Management

Adopt three elements of optimality D saturation design, moisture in the ranking areais set up 3 modes, which are drop irrigation in mountain region; soil moisturepreservation by covering with straw and the mountain soil moisture preserved infish-scale pit. Three nutritional elements are included in handling fertilizing, namely N, Pand K. After two years studying the relationship of the fertilizer efficiency, the growthand yield change of jujube and soil nutrient content under different modes of dropirrigation in mountain region, soil moisture covered by straw and mountain preservingsoil moisture in fish-scale pit, we can see the result shows:(1) Under different soil moisture in different growing period of jujube in mountainregions, K3 treatment is berrer for the growth rate of new shoots.It reached 17.59cm,11.94cm and 9.87cm respectively in drop irrigation ,straw mulching and fish-scale pitconditions.The order of three soil moisture on new branch growth is:dropirrigation>straw mulching>fish-scale pit.Comparing with other treatments,thechlorophyll content and diameter expanding of N3P3K1 treatment is the biggest underdrop irrigation condition far above the numeric value under strae mulching and fish-scalepit condtions witch reached 26.55mg/g and 1.4cm.(2)Fertilization significantly increased the jujube yield and the effect is differentwith different fertilizer. In the year 2009,K3 treatment is better for the fruit-bearing rate inthe three saving water measures and the highest fruit-bearing rate reached 12.8% onmountain drop irrigation.The order of different soil moisture on fruit-bearing rate is :dropirrigation>straw mulching>fish-scale pit. In the year 2010,the highest fruit-bearing ratewas obtained by N2P2 treatment while that of K3 decreased by 25.14% compared to thefruit-bearing rate of 2009 under the condition of mountain drop irrigation. After twoyears fertilization ,the yield of jujube in N₁P₃K₃ treatment is the highest among the threewater saving measures. In the year of 2010, , the yield of jujube can reached21026.8kg/hm² under mountain drop irrigation and net income is 415724yuan/hm²;Under mountain straw much condition,the yield of jujube reached 17984.8kg/hm² and netincome is 350975.5yuan/hm²;The yield of jujube under fish-scale pit is lower than thetwo other conditions which reached 1335.1kg/hm² and the net income is257981.5yuan/hm².(3) After two years fertilization treatment with the single use of N,P,K,the output ofyield per unit fertilizer has the same trend under three soil moisture:K>N>P. The resultsobtained indicated that N and K are the major factors affecting the jujube yield on loessplateau,especially the application of K fertilizer on hillside jujube farm.The combinationof NPK can increase the fertilizer contribution rate significantly and the effect ofdifferent soil moisture and years also has a difference. In the year 2009,the contributionrate of N₁P₃K₃ treatment reached 24.38%,55.69% and 47.56% respectively under dropirrigation,straw mulching and fish-scale pit condtions.While in the year 2010,the highestcontribution rate is 59.36%.It was obtained by N₁P₃K₃ treatment under straw mulchingcondion which is 2.73 and 1.25 times than that under drop irrigation and fish-scale pitcondition. The results showed that the conservative use of fertilizer can improve thejujube yild by regulating the water content of soil in a certain degree of drought.(4) Fertilization can improve soil nutrient content and soil fertility.The resultsshowed that with the single use of N,P,K fertilizers,soil organic matter of P3 treatment isthe highest and reached 8.03g/kg in 0-20 cm layer;N3 treatment achieved goog results ontotal N and available P content by reaching 0.80g/kg and 20.78mg/kg respectively;Soilabailable K content was obtained to 398.35mg/kg by using single K fertilizer. The effectof NPK fertilizer combination was the most obvious.Soil organic matter,total Ncontent,available P and avalibale K in N₁P₃K₃ treatment reached15.16g/kg.0.93g/kg.45.02mg/kg and 763.77mg/kg respectively compared to CKtreatment.After two years,the NO3-N accumulation content increased significantly andmainly stroed in the layer of 20-60cm.Applying with P and K fertilizer can reduce theaccumulation of NO3-N.There is no difference of NH4-N content between differentfertilized treatment and it was equally disreibuted from 0-60cm layer.(5) Based on the factors interaction ,we can find the effects of poor nourishment insoil on jujube yield under different soil moisture.Under the drop irrigationcondition,lacking of K has the biggest jujube yield. Lacking of N is on the second placeand lacking of P is the third.On the condition of straw mulching,the jujube yield oflacking N is the greatest and secondly is lacking of P.Lacking of K is the nect.Thesituation under fish-scale pit has the same trend as that in straw mulching condition. (6) Established mathematical regression model of different fertilization applying forjujube yield under different moisture conditon, and received the optimum N,P,Kfertilization for jujube yield under different moisture condition. Under the mountain dropirrigation,the optimum rates of N,P,K fertilizer for realizing the yield goat of18000²5000kg/hm²isN :829.95¹367.85kg/hm²,P2O5:1706.1²859.45kg/hm²,K2O:447.15⁴80.8kg/hm²; Under the straw mulch condition, the optimum rates of N,P,K fertilizerfor realizing the yield goat of 15000¹8000kg/hm² is N:131.34¹148.4kg/hm²,P2O5:759³031.05kg/hm², K2O:724.35⁸05.24kg/hm²; Under the mountain fish-scale pit,the optimum rates of N,P,K fertilizer for realizing the yield goat of 12000¹5000kg/hm²is N: 679.8¹181.4 kg/hm², P2O5: 826.65²222.55 kg/hm², K2O: 333.3⁷22.7 kg/hm².