摘要
土层厚度作为土壤的关键属性,决定了生根空间、水分和养分储量等影响植物生长的一系列条件。为探究不同土层厚度下山地枣树土壤水分状况及耗水策略,构建足够大且可控制的土体空间,设置2、3、4、5、6 m共5种土层厚度的试验小区,对其土壤水分进行定位观测。结果表明,枣树耗水量随着土层厚度的增加呈现先降低后增高的变化趋势,浅土层抑制了枣树地上部分的生长而加强了细根的生长发育,越厚的土层枣树生长状况越好,细根生长发育随之得到加强;土层越厚,枣树土壤水分状况越好,2~4 m深土层在11 a枣树耗水下深层土壤水分已邻近凋萎湿度,此后枣树耗水仅能依靠降雨补充,5 m和6 m深土层因土壤储水充足其浅层土壤水分较2~4 m深土层更高;不同土层厚度下降雨补给量和补给深度不同,厚土层较浅土层降雨补给深度更深。因此,枣树在深层土壤储水严重缺乏的浅土层中会抑制自身生长发育而加强根系吸水能力,随着土层厚度与深层土壤储水的增加,枣树保持着深层土壤储水越多、生长状况越好、耗水量越多的规律。该研究阐明了枣树为适应土层厚度带来的土壤储水量差异其耗水机制的改变,揭示了深层土壤储水对枣树生长耗水的影响,研究结果可为干旱区植被恢复与重建提供一定的理论依据。
Soil thickness is a key feature to determining a series of conditions that affect plant growth,such as rooting space,water and nutrient storage.In order to explore the soil water consumption strategy of jujube trees within varying soil layers,a large enough and controllable soil space was constructed in this study.Experimental plots with five soil layers(i.e.,2,3,4,5 and 6 m,respectively)were set up for localized observation of the changes in soil water.The results showed that the water consumption of jujube trees decreased first and then increased with the increase of soil layer thickness.Shallow soil layer inhibited the growth of aboveground part of jujube trees,but strengthened the growth and development of fine roots.Thicker soil layer,in contrast,benefited the growth of above-and underground parts.The thicker the soil layer,the better the soil moisture condition.The soil moisture in the depth of 2 to 4 m was close to the withering humidity point under the water consumption of 11-year-old jujube trees.The water consumption,therefore,was expected to be supplemented by rainfall.The soil moisture at shallow soil layers of 2 and 4 m was higher than that at deep soil layers of 5 to 6 m.The rainfall recharge amount and depth differed at varying soil layers.The rainfall recharge depth was deeper in thick soil layer than in shallow soil layer.Therefore,jujube trees might inhibit their growth and development in shallow soil layer.The water storage in deep soil was severely constrained by a lack of water absorption capacity from roots.With the increase of soil thickness and water storage,jujube trees maintained more water storage in deep soil.This study elucidates the change in water consumption mechanism of jujube trees for the adaptation to variation of soil water storage in relation to soil thickness.Our results reveal the influence of deep-soil water storage on the growth and water consumption of jujube trees,providing a theoretical support for vegetation restoration and reconstruction in arid areas.
作者
冯喆
马理辉
王志昊
FENG Zhe;MA Li-hui;WANG Zhi-hao(College of Water Resources and Architecture Engineering,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Northwest A&F University,Yangling 712100,Shaanxi,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and Ministry of Water Resources,Yangling 712100,Shaanxi,China)
出处
《西北林学院学报》
CSCD
北大核心
2024年第1期140-146,共7页
Journal of Northwest Forestry University
基金
国家重点研发计划(2021YFD190070402)。
关键词
土层厚度
土壤水分
枣树
耗水
垂直分布
soil layer thickness
soil moisture
jujube tree
water consumption
vertical distribution
