Appropriate Surge Spring Root Irrigation Layout And Irrigation Norm Of Jujube On Mountain Land

The appropriate emitter layout and irrigation norm of surge spring root irrigation for mountain land jujube trees were studied. The experimental trees were five years old pear-jujube, choose surge spring root irrigation emitter layout and irrigation norm as experimental elements. The preliminarily research results as follows:(1) Soil wetting body character of surge spring root irrigationThe relationship between soil wetting front migration distance and irrigation time, soil wetting front migration speed and irrigation time were power relation, and the correlation coefficients were above 0.97; the soil wetting bodies didn't interference each other, soil wetting front migration distance, soil wetting body volume and wetting radius were increased as irrigation norm increased; The highest water content of soil wetting body was at the emitter water outlet area, soil water content from 28% to 30%, and then decreased lightly to periphery, at the wetting front area were decreased to 16%-17%.(2)Soil water content and soil water potential dynamic trends of surge spring root irrigationThe soil water content of each treatment were from 10% to 25%, the diversity were significantly among treatments, the soil water content of 30~80cm was higher than 0~30cm, 0~ 20cm was the lowest area, only near 10%. Under the same irrigation norm, the soil water status and soil water potential of two emitters per tree treatments were relatively better, which was better to jujube tree root absorb soil water.(3) The effect of surge spring root irrigation on jujube trees physiological and growth indexes.The jujube leaf water potential was between 0.6 to 3.0Mpa, generally speaking, the more irrigation water, the higher leaf water potential was, this indicate leaf water potential was impacted deeply by soil water content, irrigation impact jujube leaf water content directly, and through this impact jujube growth. From jujube trees sprout to June 15th, new breach and leaves growth quickly, and then into an slowly growth ages until stop growth, at early stage there were no significantly difference between treatments, but as time shifting, the difference gradually widening; The fruits diameter of each treatment were between 3.65 and 4.31cm, the difference were significantly among treatments, generally speaking, as irrigation norm increase, the fruits diameter increase too.(4)Water consume, yield and water use efficient of each treatmentThe water consume of each treatment jujube trees were among 403.5 and 458.9mm, at stageâ…¢the jujube trees consume most water, average 174mm, optimal evapotranspiration rate was 3.5mm/d; and then was stageâ…¡,average water consume was 100mm, optimal evapotranspiration rate was 2.5mm/d; show that this two stages were water use critical periods, need irrigate more water to jujube trees; Generally speaking, jujube surge spring root irrigation can save water by 67~80% compare to conversation irrigation way, and WUEET was higher, average to 3.9kg/m3, under appropriate layout and irrigation norm, it could come to 4.3kg/m3; the WUEM of each treatment were among 22.5 and 38.0kg/m3, the difference were significantly among treatments, the WUEET and WUEM of T6 and T10 were higher than the other treatments; Under appropriate emitter layouts and irrigation norm, fruit yield could come to 17000kg/hm2, 26% higher than conversation irrigation norm.(5) The jujubes economic effects of each treatmentCompare with traditional irrigation, surge spring root irrigation need some investment, mainly field construction costs, management fee, maintenance fee and irrigation emitter fee, but its output was large, mainly reflected in the economic output increase, labor cost decrease and water cost decrease. The net returns of difference treatments were between 42 to 18856 yuan per Ha, average 9837 yuan per Ha, but irrational surge spring root irrigation emitter layout and irrigation norm would decrease the economic benefits.