Effects Of Water-saving Irrigation On Yield And Quality Of Red Jujube In Semiarid Mountainous Areas Of Northern Shanxi

For the characteristic economic forest fruit,red jujube,has widely planted in the semiarid mountainous area of northern Shaanxi,due to drought and water shortage and soil erosion,the relationship between supply and demand of jujube trees has long been contradictory,resulting in the low yield,quality and economic benefits of jujube.In order to alleviate the problem of water shortage during the growth of jujube trees,this study used jujube irrigation to carry out the method of insufficient irrigation,and sought the appropriate irrigation amount of red jujube in the semi-arid mountainous areas of northern Shaanxi under drip irrigation mode.I carried out the jujube irrigation experiment in the jujube orchard jujube cooperative in the Zhujiagua Town of Jiaxian Yulin Shanxi Province.The experiment used the locally cultivated jujube variety,Oil Jujube,as the research object.Based on the water consumption regularity of jujube trees and the change of soil moisture before and after jujube irrigation in different growth stages,the physiological and ecological indicators,the yield and the quality of jujube trees under different irrigation treatments were analyzed in detail,and the optimal irrigation method of mountain red jujube under drip irrigation method was optimized by using the approximation ideal solution comprehensive evaluation method in information entropy theory.It provides a scientific basis for the development of water-saving and efficient jujube irrigation in semi-arid mountainous areas of northern Shaanxi.The following results have been achieved:(1)According to the meteorological data measured by the small meteorological station installed in the test site,the study on the water consumption law of jujube trees in different growth stages found that the potential water consumption of jujube trees is 335.82 mm,and the water deficit is 60.08 mm,of which the most serious was in flowering and fruit setting stage.Through comprehensive analysis of the soil moisture dynamics of jujube trees in the experimental area,it was found that there were significant differences in soil moisture between the irrigation treatment and the non-irrigation treatment during the growth period.The soil moisture in the irrigation treatment was higher than the control treatment,and the soil moisture towards stability after the fruit ripening period.In the vertical direction,the water structure with high moisture content in the surface layer and deep soil,and low moisture content in the middle layer soil is exhibited.The water content of the surface layer and the middle layer of the soil increased after irrigation.(2)Through continuous monitoring of the ecological indicators of jujube growth and comparative analysis,it was found that the irrigation treatment was significantly higher than the control treatment in the length of new shoots,the length of jujube crane and the crown size of jujube trees,showing a positive correlation.The length of jujube crane in irrigation treatment increased by 1.73%~6.48% compared with the control treatment,and the length of jujube new shoots in irrigation treatment increased by 5.56%~16.59% compared with the control treatment.The size of crown diameter in irrigation treatment increased by 5.28%~11.39% compared with the control treatment.It is indicated that supplementing irrigation in the dry period of jujube in northern Shaanxi is conducive to promoting the growth of jujube trees.By determined the yield of jujube trees.It was found that the number of fruit set,fruit yield and water production efficiency of jujube trees were better than that of the control treatment,and the fruit cracking phenomenon of jujube trees was also alleviated.The irrigation treatment increased by 2.01%~19.26% compared with the control treatment,and the water production efficiency increased by 4.39%~13.22%.The rate of fruit cracking decreased by 10.42% to 14.24%.By measuring the physical and chemical quality indicators of different treatments,it was found that the irrigation treatment was mostly higher than the non-irrigation treatment in terms of fruit volume and fruit quality,but the differences in chemical quality indicators were not obvious.(3)Using the method of approximating ideal solution based on information entropy theory,comprehensively considering the irrigation quantity,yield,quality and other indicators under different treatments to establish a comprehensive benefit evaluation model for red jujube in semi-arid mountainous areas of northern Shaanxi,and I obtained the best drip irrigation amount of mountain red jujube.For the climatic conditions of 2018,the jujube trees in the test area(four-year-old jujube trees,about 60 trees per mu),each pond is supplemented with 200 L(equivalent to 18 mm precipitation),and the comprehensive benefits are relatively high.