Optimization Of Drip Irrigation Belt Layout Mode Of Red Jujube In Southern Xinjiang And Study On The Growth And Quality Improvement Efficiency Of Boron-zinc Microfertilizer

Poor water retention capacity of desert soils in the Southern Xinjiang Sandy Area makes the water use efficiency of the area extremely low.At the same time,the extremely arid and large evaporation conditions limited the growth of jujube.In view of this situation,this study studied the redistribution characteristics of water infiltration under different discharge and spacing by means of point source infiltration test,boron-zinc micro fertilizer coupling test and jujube growth model,and optimized the layout pattern of drip irrigation belt in this area in combination with the root distribution of jujube;determined the most suitable spraying amount and spraying method of boron-zinc micro-fertilizer for improving jujube quality;and clarified the mechanism of boron-zinc micro-fertilizer on jujube growth and photosynthetic physiological characteristics and established the relevant model.The main results are as follows:(1)Under magnetoelectric water drip irrigation,the 3 L/h drip flow rate and drip spacing of 20 cm can effectively maintain soil moisture,and the soil storage is 27.76%～53.47%higher than that of other treatments;At the same time,according to the root distribution and water consumption of jujube,the optimal drip irrigation belt arrangement of jujube was determined,and the drip irrigation belt arrangement was two tubes in one row,and the drip irrigation belt spacing was 200 cm.(2)Under magnetoelectric water drip irrigation,the combined application of boron-zinc microfertilizer can significantly promote the growth and development of jujube trees and improve the growth and physiological characteristics of jujube trees.Among the growth indexes,the length of jujube hanging,leaf area index,fruit cross diameter and longitudinal diameter were increased by 18.25%,25.80%,22.13%and 32.19%,respectively.Among the photosynthetic physiological indexes,the maximum net photo synthetic rate,transpiration rate and stomatal conductance increased by 90.45%,91.43%and 75.3%,respectively,while the maximum decrease in intercellular CO2 was 13.09%.(3)Applying boron and zinc fertilizer can significantly improve the yield and quality of jujube and the water use efficiency of jujube.When the application rate of boron fertilizer was 4.5 kg/hm2 and zinc fertilizer was 3.0 kg/hm2,the maximum irrigation water use efficiency was 3.56 kg/m3 and the maximum water use efficiency was 3.91 kg/m3,increasing by 17.11%and 12.68%respectively.When the application rate of boron fertilizer was 4.5 kg/hm2 and zinc fertilizer was 3.0 kg/hm2,the maximum yield of jujube was 10684.05 kg/hm2,increasing by 16.95%.The content of soluble sugar,titratable acid and flavonoids in jujube fruit could be increased by applying boron and zinc at 4.5 kg/hm2 and 3.0 kg/hm2 respectively.(4)The Logistic model can well describe the variation process of leaf area index(R2=0.95).The theoretical maximum LAI is 2.69 when the application rate of boron fertilizer is 3.50 kg/hm2 and zinc fertilizer is 3.35 kg/hm2.By establishing a prediction model for jujube yield based on micro-fertilizer application,it can be seen through model simulation that when boron fertilizer application is 3.59 kg/hm2 and zinc fertilizer application rate is 3.32 kg/hm2,the theoretical maximum value of jujube yield is 10581.87 kg/hm2.Based on the effect of boron and zinc fertilizer on jujube growth,jujube yield and quality,the best spraying method is boron fertilizer 3.0～4.5 kg/hm2 and zinc fertilizer 3.0～3.5 kg/hm2.