高矿化度水灌溉条件下土壤盐结皮层与下层土壤盐分特征差异初探  

The variability of salt characteristics from salt crust to subsoil in the shelterbelts along Tarim desert highway

作　　者：许波[1] 张忠良[1] 王永东[2] 王晓静[2] 

机构地区：[1]中国石油天然气股份有限公司塔里木油田分公司,库尔勒841000 [2]中国科学院新疆生态与地理研究所,乌鲁木齐830011

出　　处：《干旱区资源与环境》2014年第7期116-120,共5页Journal of Arid Land Resources and Environment

基　　金：国家自然科学基金项目(41271341;41030530);中国石油天然气股份有限公司塔里木油田分公司综合项目(971012080007)资助

摘　　要：塔里木沙漠公路防护林生态工程沿线均采用高矿化度咸水灌溉,土壤盐分是该线新人工生态系统可持续面临的主要环境问题之一。为了探讨长期灌溉条件下土壤表层盐分与土体内部盐分差异性,在沙漠公路定点采样的基础上,运用统计分析、相关分析等对土壤盐结皮层与盐结皮层下(0-100cm)土层电导率、全盐量的关系、盐离子含量、各土层盐离子间相关性关系做了比较分析。结果表明:盐结皮层土壤盐分显著高于下层土壤,沿线不同层次土壤pH均呈碱性,处于弱变异程度,相比较盐结皮层更趋向于碱性。长期高矿化度水灌溉下,盐结皮层土壤盐分离子与结皮层下(0-100cm)盐分离子在剖面出现显著分异。盐结皮层以NaCl、CaSO4、MgSO4、MgCl2等盐类为主,而盐结皮下土壤以NaCl、Na2CO3、MgCl2、MgCO3盐类为主。这是极端干旱区长期高矿化度水灌溉下盐分离子淋溶-积聚的显著表现。The Tarim desert highway is the large - scale shelterbelt project by using the local underground saline water with drip irrigation. But in extreme arid area and with high salinity water drip - irrigation, it is hard to maintain the normal growth of shelterbelt because of higher concentration of salts. Surfaces soils and subsoil （0 - 100cm） of shelterbelt fields were collected to analyze the relations of the conductance rate and content of ion, total salt concentrations and composition of ions in the 40 soil profiles along the Tarim desert highway. Statistical analysis and correlation analysis were used to probe the soil saline characters. The results showed that the relation between EC and salt content of subsoil was evident in linear relation and better than the salt crust layer. The correlation coefficient was 0.9534 and 0.8511, respectively. Salt accumulated strongly at surface soil, salt content of surface layer was the highest and decreased fastly from surface layer to lower layers, salt accumulation further intensified with irrigation continuance which was the most basic characteristics of soil salt in the Tarim desert highway shelterbelt. The total salt content of salt crust was rapidly increased and exceeding subsoil with different layers of subsoil. The coefficient of variation was completely presented medium variations. The coefficient of variation of pH was rather weak and tended to be more alkaline in the salt crust. The ion content was appeared sig- nificant differentiation from the salt crust to subsoil with 0 - 100 cm. The results are provided some scientific insights on the plant growth of the sheherbelts along the Tarim desert highway as well as the evolution of soil salt. In addition, these results can also shed a light on the sustainability of shelterbelts along the Tarim desert highway.

关 键 词：塔里木沙漠公路 防护林 盐结皮 差异性 

分 类 号：S156.46[农业科学—土壤学]