黄河三角洲海水灌溉对土壤盐碱化和导水率的影响

为研究海水灌溉对土壤盐碱化和导水率的影响，该文在黄河三角洲滨海盐渍土上采用75%的海水于田间小区进行3年灌溉试验，分析了海水灌溉前后土壤含盐量、土壤盐碱化的各项指标、土壤中各种离子和饱和导水率的变化，结果表明：采用75%的海水灌溉后土壤剖面中盐分含量明显升高，在土层80 cm以下有盐分积累的现象；而饱和导水率减小；土壤的pH值在海水灌溉前后变化不大；残余碳酸钠(RSC)的变化也较小；土壤的钠吸附比(SAR)和碱化度(ESP)在3年海水灌溉后上升较大，已经超过了碱化土壤的临界值，并均与土壤中的盐分含量呈对数曲线变化。在黄河三角洲地区运用海水灌溉可能会对土壤资源安全产生影响，海水灌溉必须防治次生盐渍化和土壤碱化的发生。

Effects of seawater irrigation on soil salinize-alkalization and saturation conductivity in Yellow River Delta

To study the effect of seawater irrigation on soil salinize-alkalization and saturated hydraulic conductivity, 75% seawater was applied to irrigate in field experimental plots in the seashore saline soil of Yellow River Delta in three years. The change of the soil salt content, index of soil salinize-alkalization and soil saturated hydraulic conductivity before and after seawater irrigation were analyzed. The results are as follows: the salt content increases in soil profiles after 75% seawater irrigation. The salt accumulation can be found below 80 cm of soil layers. The soil saturated hydraulic conductivity decreases after seawater irrigation. The pH values of soil and the residual sodium carbonate(RSC) do not change any more before and after seawater irrigation. Sodium-adsorption ratio(SAR) and exchangeable sodium percentage(ESP) of soil rise and surpass the critical value of alkali-affected soil after seawater irrigation in three years. SAR and ESP with the salt content of soil are in a good relationship with logarithm. Therefore, seawater irrigation can affect safety of soil resources in the Yellow River Delta. The secondary salinization and alkalization of soil must be prevented in the process of seawater irrigation.