明沟排水对盐渍化枣田土壤盐分的影响

[目的]研究明沟排水对盐渍化枣田土壤盐分分布规律的影响,明确明沟排水降盐效应,为提高枣树经济效益和生态防护效应以及盐渍土长期改良治理措施研究提供理论依据。[方法]通过对盐渍化枣田土壤进行调查取样,并对该土样进行水溶性盐含量、电导率、pH值和土壤盐基离子当量比的测定。[结果]同一深度土层,随着与明沟距离的增加,盐基离子含量呈现先降低后增加趋势。距离明沟0m处盐基离子含量最高,之后随距离的增加含量显著降低,在40m处达到最低,40m以后盐基离子含量显著增加。此外,距离明沟40m处土壤盐害作用明显降低,盐基离子类型由NaCl型转变为盐害较轻的CaCl_2型和Na_2SO_4型。[结论]明沟排水降盐效果最佳的范围在40m左右;由于滴灌和离子迁移速率等因素的影响,在土壤表层和底层出现了盐基离子聚集现象。

Effects of Ditch Drainage on Soil Salinity in Salinized Jujube Field

[Objective] The effects of drainage ditch on the distribution of soil salinity in saline soil were studied, and the effects of water and salt reduction in clear gully drainage were clarified to provide theoretical basis for improving the economic benefits and ecological protection of jujube and the long-term improvement measures of saline soil.[Methods] The effects of drainage on the salinization of salinized jujube soil were studied. The soil samples of salinized jujube fields were sampled. The contents of water soluble salt, electric conductivity, pH value and equivalent proportion of salt base cation were measured.[Results] The content of salt ions decreased first and then increased with the increase of the distance from the ditch. The content of salt ions was the highest at 0 m, and then decreased with the increase of distance, reached the lowest at 40 m, the content of salt ions increased significantly after 40 m. In addition, from the ditch of 40 m, wherein soil salt damage shifted and decreased from NaCl cation type of severe degree into CaCl₂ and Na₂SO₄ caused mild degree.[Conclusion] The best effect of ditch drainage salt reduction was observed around 40 m from the ditch. Impacted by drip irrigation and ion transport rate and other factors, salt ion aggregation phenomenon emerged in the soil surface and at the bottom as well.