基于^(18)O示踪的不同树龄枣树土壤水分利用特征分析  

Characteristics of soil water utilization for different stand ages of jujube trees based on ^(18)O tracking

作　　者：赵西宁[1,2] 李楠 高晓东[1,2] 霍高鹏 潘燕辉[4] 

机构地区：[1]西北农林科技大学水土保持研究所,杨凌712100 [2]中国科学院水利部水土保持研究所,杨凌712100 [3]西北农林科技大学水利与建筑工程学院,杨凌712100 [4]兰州大学西部环境教育部重点实验室,兰州730000

出　　处：《农业工程学报》2018年第3期135-142,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金："十三五"国家重点研发计划(2016YFC0400204;2017YFC0403605);国家自然科学基金(41571506;41771316;51579212)

摘　　要：为明确不同树龄枣树的水分利用特征。该研究利用稳定氧同位素(^(18)O)示踪方法,测定4个不同树龄(4、8、17和22年)枣树的木质部水与潜在水源的氧同位素比率δ^(18)O值,利用Mix SIR模型定量计算各树龄枣树对潜在水源的利用比例。结果表明,浅层(0~40 cm)土壤水分相对充足时期,枣树主要吸收浅层土壤水分,浅层土壤水分匮乏时,枣树会增加中层(>40~120 cm)和深层(>120~200 cm)土壤水分的吸收比例。萌芽展叶期不同树龄枣树都主要吸收浅层土壤水分;开花坐果期,随着树龄的增加,枣树对浅层土壤水的吸收比例逐渐减少,对深层土壤水的吸收比例逐渐增加;果实膨大期,4年生枣树主要吸收中层土壤水分,8年生枣树主要吸收深层土壤水分,而17和22年生枣树主要吸收浅层土壤水分;果实成熟期,8和17年生枣树分别主要吸收浅层和深层土壤水分,22年生则主要吸收中层土壤水分。根据不同树龄枣树的水分利用特征对其进行水分管理以减少4、8年生枣树浅层土壤水分的非生产性耗水及17、22年生枣树自身奢侈性耗水,实现红枣林的长期健康发展。Since the initiation of the large-scale ecological rehabilitation project by the Chinese central government in 1999,jujube forest was widely cultivated in the loess hilly region,due to its ecological and economic benefits.Soil moisture is a key factor affecting jujube growth.Clarifying water use strategy of jujube trees of different stand ages can provide useful indications for the water management of jujube forest in this area.In 2016,we selected 4 different stand ages（4,8,17 and 22years）of jujube forests in a rain-fed jujube（Ziziphus Jujube cv.Lizao）plantation in Qingjian County,Shaanxi Province（37°15′N,118°18′E）.In the study,the oxygen stable isotope tracer method was used to measure the oxygen isotope ratio（δ^（18）O）of xylem water and soil water sources in jujube orchards with 4 different stand ages,and the contribution of soil water from different depths to water uptake was estimated by the Mix SIR Bayesian mixing model.The results showed that soil moisture and soil waterδ^（18）O varied across soil depths and sampling dates,which were influenced by the rainfall and evaporation.The composition of soil water isotopes and rainfall isotopes showed the same temporal trend.In arid and semi-arid areas,with the variation of soil moisture,jujube trees of different stand ages could adjust the utilization structure of soil water to adapt to the soil water environment changes.Jujube tree mainly absorbed soil water from shallow soil（0-40 cm）when soil water was available.However,when shallow soil water was scarce,jujube tree mainly absorbed the soil water from middle layer（40-120 cm）and deep layer（120-200 cm）with the stand age increasing,leading to the middle and deep soil water content close to wilting point（7%）.In germination stage（May 29^（th））,jujube trees mainly absorbed shallow soil water.With the increase of stand age of jujube trees,the ratio of water absorption for jujube trees from shallow soil water gradually decreased,whereas the proportion of deep soil wate

关 键 词：土壤 水分 同位素 枣树 树龄 MixSIR模型 

分 类 号：S152.7[农业科学—土壤学]