黄土丘陵区雨养梨枣树生长对初始土壤含水率的响应

以6年生矮化密植梨枣树(Ziziphus jujuba Mill.)为试材,在雨养条件下,设置4种不同初始土壤体积含水率水平(1区,15.17%;2区,14.33%;3区,11.34%;4区,8.61%),测定并分析土壤水分变化、枣树生长、枣树耗水及其产量。结果表明:在雨养条件下,随着时间的推进,4个小区的土壤体积含水率不断接近,由最初的有显著差异变为没有显著差异;梨枣林地在低土壤水分情况下,可以通过自然降雨修复干层;4个小区的生物量和产量都是随着初始土壤含水率的减小在减小,且小区之间产量差异显著;4种初始土壤水分条件下,4个小区获得的产量分别为21 744.9、18 648.0、12 354.3 kg·hm~(-2)和6 660.0 kg·hm~(-2),说明即使在初始土壤水分亏缺情况下,在平水年也可以得到一定的产量;高度为0.9~1.2 m,冠幅为0.5~0.9 m的梨枣树,产量却达到最高21 744.9 kg·hm~(-2),说明梨枣获得高产不需要高大的树体,所以矮化密植具有很大潜力。

Response of jujube growth to initial soil water content in rainfed regions in Loess Plateau

With 6-year-old dwarfed densely Ziziphus jujuba Mill .as experimental materials ,four different initial soil volumetric water content levels (plot 1 ,15 .17% ;plot 2 ,14 .33% ;plot 3 ,11 .34% ;plot 4 ,8 .61% ) were per-formed under rainfed conditions ,and soil water variation ,jujube growth ,jujube water consumption and yield were deter-mined .The results showed that under rainfed conditions ,with the passage of time ,soil volumetric water content of the four plots were nearly the same .There were significant differences among four plots .At low water conditions ,dry layer of jujube plantation can be repaired through natural rainfall .Biomass and yield decreased as the initial soil water content decreased ,and yield among plots were significantly different . The yield of four plots were 21 744 .9 , 18 648 .0 , 12 354 .3 ,and 6 660 .0 kg·hm-2 ,respectively ,suggesting that considerable yield can also be obtained in normal pre-cipitation year even if the initial soil water content under deficit conditions .Jujube with height of 0 .9~1 .2 m and crown of 0 .5~0 .9 m ,had the high level of yield ,as high as 21 744 .9 kg·hm-2 ,indicating large potential of dwarfed densely jujubes .The results can be applied for local rainfed jujube production and management .