Effect Of Vertical Subsurface Infiltration Irrigation On Water Consumption And Growth Of Jujube Trees

For conventional surface irrigation soil moisture distribution of shallow,can't solve the root water supply to the path is long and low water use efficiency of horticulture water problems,combined with the feature of Chinese jujube root system distribution,with underground pipe and Ningxia Lingwu long jujube as the research object,set different vertical underground tube length(L1:10 cm,L2:20 cm,L3:30 cm,L4:40 cm)indoor simulation test,soil water infiltration irrigation quota and jujube(W1:210 mm,W2:300 mm,W3:390 mm)and vertical underground tube with different buried depth(D1:10 cm,D2:20 cm,D3:30 cm)of field experiment,the analysis of underground vertical soil water infiltration characteristics with different processing on jujube water consumption at each development,growth and development indexes and water use efficiency,the influence of Chinese jujube underground vertical suitable irrigation quota and depth,as to provide theoretical basis for the application of underground vertical technology.(1)The test results of the effect of different pipeline lengths of underground vertical infiltration irrigation on soil moisture infiltration characteristics show that:under the same irrigation time,the moving speed of the wet front increases with the increase of the pipeline length.Under the same irrigation quota,the shape of the contour lines of soil moisture content in different lengths of infiltration irrigation pipes is not much different,and they are all similar to "ellipsoids".The longitudinal size of the wetted body is L4(greater than 100 cm)>L3(98.67 cm)>L2(97.24 cm)>L1(84.24 cm),the horizontal size is L1(57.53 cm)>L2(52.02 cm)>L3(49.42 cm)>L4(45.29 cm),and the soil moisture content showed a trend of gradually decreasing from inside to outside.The water content of the soil at the outlet of the irrigation pipe was 18.68%?22.56%,and the soil water content at the soil wetting front decreased to 10.03%?11.34%.(2)The experimental results of the effect of underground vertical infiltration irrigation on the water consumption law and crop coefficient of jujube trees show that:under the same irrigation quota,the water consumption and crop coefficient of jujube trees increased first and then decreased with the increase of the buried depth of the infiltration irrigation pipe.When the irrigation quotas W2 and W3 were treated,the depth of the pipeline has a weak influence on the water consumption of jujube trees and crop coefficients,and the difference between water consumptlion and crop coefficients is small.Under the same pipeline burial depth,the water consumption and crop coefficients of the jujube trees in each growth period and whole growth period in 2018 and 2019 are W3>W2>W1.Under the condition of vertical underground irrigation,under the same water treatment during the whole growth period,the crop water consumption,daily average water consumption intensity and crop coefficient of each growth period showed a trend of increasing first and then decreasing with the progress of the growth period,and the fruit expansion period reached the maximum value.(3)The test results of the effects of different depths of underground vertical infiltration irrigation and irrigation quota on the growth and development of jujube trees show that:Under the same irrigation quota conditions,compared with D1 and D3 treatments,D2 treatment can significantly promote the increase of jujube tree new shoot diameter,jujube hanging length and fruit setting rate,while the jujube tree output increased by 4.45%?24.53%,water use efficiency Increase by 0.11%?22.54%.Compared with the W1 treatment,the W2 and W3 treatments can significantly increase the growth of jujube tree new shoot diameter,jujube hanging length,fruit setting rate and yield under the D2 condition of infiltration irrigation pipe buried depth.When the irrigation quota is increased from W2 to W3 There was no significant difference in output(P>0.05).In 2018 and 2019,the water use efficiency decreased by 21.22%and 16.50%.Therefore,underground vertical infiltration irrigation is more suitable for the growth of jujube trees when the irrigation quota is 300 mm and the burial depth is 20 cm,and it helps to increase yield and water use efficiency.In this paper,through the indoor simulation test and field positioning test,the soil moisture distribution characteristics of underground vertical infiltration irrigation and the suitable irrigation quota and optimal placement position of jujube trees are initially determined,which provides scientific basis and technical support for jujube tree water management and precision irrgation Provide a theoretical basis for the application of underground vertical seepage irrigation technology.