Root Spatial Distribution and Soil Moisture of Jujube Under Different Irrigation Depth

Taking the densely planted jujube trees in Southern Xinjiang as test materials, the root distribution and soil water changes of jujube trees under four levels were studied by setting different water conduit lengths, the effects of different irrigation depths on the root spatial distribution and soil water of jujube trees in Southern Xinjiang were studied, in order to provide reference for irrigation moder of improving water use efficiency.The results showed that in the horizontal direction, the root length density decreased with the increase of horizontal distance under different treatments.Most of the roots were distributed in the range of 0-60 cm.Under each treatment, the effective root length this range（d＜2 mm） accounted for 81.1%,83.6%,81.4% and 84.8% of the total effective root length respectively.In the vertical direction, compared with T0 group, the effective root length within the outlet range of each treatment increased by 3.5%,4.2% and 2.2% respectively.Indicating that increasing the irrigation depth promoted the growth of effective roots.The root length density in horizontal and vertical directions decreased with the increase of distance.The fitting study of nonlinear parameters showed that the exponential model could well reflect the two-dimensional distribution of jujube roots.Properly increasing the irrigation depth could not only ensure that the upper soil had enough water, but also realize deep water supply.This study suggests that the buried depth of the water guide device of adult jujube was about 35 cm.