大田原生盐碱荒地入渗特性的试验

为揭示原生盐碱荒地土壤的入渗特性,基于大田原生盐碱荒地4个试验点的原位土壤入渗试验,并与非盐碱土壤入渗特性比较,探讨了盐碱荒地土壤的入渗的过程和特性。结果表明:原生盐碱荒地的入渗过程与非盐碱荒地相类似,但其累积入渗量和入渗率远小于非盐碱地,且入渗率的衰减速度远快于非盐碱地,究其原因是由其水力传导度小所导致,而水力传导度小的根本原因是由于盐碱土壤中含有较多的交换性钠离子;盐碱土壤的累积入渗量和相对稳定入渗率与其含盐量、Na+离子含量间呈反比例关系;其入渗过程也可用Kostiakov模型来表征,用与Kostiakov两参数模型结合的分段模型可获得更好的表征精度。研究结果对于推进土壤水分运动理论的研究具有一定的意义,可为原生盐碱荒地的改良提供技术支撑。

Study on infiltration characteristics of original saline-alkali wasteland

In order to reveal infiltration characteristics of saline-alkali wasteland soil (SAWS), based on situ soil infiltration experiment of the four testing points in the fields and by comparing with infiltration characteristics of non saline-alkali soil, the infiltration process and characteristics of SAWS were discussed. The results show that the infiltration process of SAWS is similar to that of non saline-alkali soil, but the cumulative infiltration and infiltration rate of SAWS are far smaller than those of non saline-alkali soil, and the decay rate of infiltration is faster than non saline-alkali soil. The reason is that the hydraulic conductivity of SAWS is small, which is caused by the existing of exchanged sodium ion in great numbers; The cumulative infiltration and stability infiltration rate of SAWS have inverse proportion relationship with salt content and Na+ ion content in soil; The infiltration process of SAWS can be expressed by Kostiakov models, but the subsection model combined with two-parameter Kostiakov model has better characterization precision. The result is of definite significance for propelling the research of soil moisture movement theory and can provide a technology support for the reforming of saline-alkali wasteland.