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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。
Tarim Desert Highway Shelterbelt Ecological Project along the high salinity irrigation water are salinized, soil salinity is the line of artificial ecosystems in the sustainable development of one of the major environmental problems. In order to study the difference of salinity between soil surface salt and soil under long-term irrigation, on the basis of fixed-point sampling on desert highway, statistical analysis and correlation analysis were used to analyze the effects of soil salinization and salt crust (0-100cm) Conductivity, total salt content, salt ion content, the relationship between the salt content of soil layers made a comparative analysis. The results showed that the soil salinity in the salt crust was significantly higher than that in the lower soil. The pH of the soil in different layers along the line was alkaline and weakly variable, which was more alkaline than that in the salt crust. Under the condition of long-term high salinity water irrigation, the salt ions in the salt crusts and salt ions (0-100 cm) under the crusts showed significant differences in the profile. Salt crust is dominated by salts such as NaCl, CaSO4, MgSO4 and MgCl2, while NaCl, Na2CO3, MgCl2 and MgCO3 are the main salts in salt crust. This is a significant manifestation of salt ion leaching-accumulation in long-term high salinity water irrigation in extreme arid regions.