引黄泥沙对黏质盐土饱和导水率的影响

曲英杰 毛伟兵 孙玉霞 孙池涛 孙雪蓉

摘 要：为研究引黄泥沙对黏质盐土颗粒组成和土壤饱和导水率（Ks）的影响，以滨海地区黏质盐土为研究对象，利用黄河三角洲引黄灌区亟须处理的淤积泥沙作为改良剂，分别进行了土壤颗粒组成和土壤饱和导水率测定试验。结果表明：①黏质盐土随配沙比例增大，极细砂含量由3.356 1%增长到61.461 1%，细砂含量由0.180 9%增长到2.459 7%，粗粉粒含量由47.437 4%降低至31.150 9%，细黏粒含量由29.015 3%降至3.893 9%;②土壤饱和导水率随配沙比的增大而增大，二者为极其显著的指数函数关系，决定系数为0.937 5，以理想饱和导水率为限制条件，适宜配沙比例为[45.7%，56.8%];③土壤粒级与土壤饱和导水率的作用强度大小排序为极细砂>细砂>粗粉粒>中砂>细粉粒>细黏粒>粗砂>粗黏粒>石砾;④建立了极细砂含量和细砂含量x与土壤饱和导水率的回归方程，分别为Ks=0.018 6e0.083x，Ks=0.0160 7e2.122x。

關键词：黏质盐土;引黄泥沙;土壤饱和导水率;土壤颗粒组成

中图分类号：S156.4;TV882.1 文献标志码：A

doi：10.3969/j.issn.1000-1379.2021.05.031

Abstract： In order to study the effect of the Yellow River sediment on clay saline soil particle composition and saturated water conductivity of soil， the coastal clay saline soil was taken as the object of study and using the sediment which needs to be treated urgently in the irrigation area of the Yellow River delta as the improver to determine the soil particle composition and saturated water conductivity of soil respectively. The results show that a） as the increase of the proportion of clay saline soil， the content of very fine sand is increased from 3.356 1% to 61.461 1%， the content of fine sand is increased from 0.180 9% to 2.459 7%， the content of coarse powder is decreased from 47.437 4% to 31.150 9% and the content of fine clay is decreased from 29.015 3% to 3.893 9%. b） The saturated water conductivity of soil is increased with the increase of sand distribution， showing a very significant positive exponential function correlation. The R2 value reaches 0.937 5. Taking the ideal saturated water distribution as the limiting condition， the appropriate sediment ratio is 45.7% and 56.8%. c） The order of the interaction strength between soil particle size and soil saturated hydraulic conductivity is as follows： very fine sand > fine sand > coarse powder > medium sand > fine powder > fine clay > coarse sand > coarse clay > gravel. d） The regression equations of extremely fine sand content and fine sand content and saturated water conductivity of soil are established respectively.

Key words： clayey saline soil; Yellow River sediment; soil particle composition; soil saturated water conductivity

黏质盐土是黄河三角洲地区最重要的土壤类型，其土壤物理性质一直是改良的关键与难点，其中土壤饱和导水率（Ks）低是制约黏质盐土改良的最重要因子[1-3]。土壤饱和导水率是土壤最重要的土壤水力学参数之一，决定着土壤的渗透性能和水盐运移状况，也是土壤水分与溶质运移模型中的关键参数[4-6]。郑健等[7]通过变水头渗透试验的方法研究认为土壤饱和导水率随着土壤容重的增大而降低;迟春明等[8]通过碱化盐土剖面分析认为土壤饱和导水率与土壤有机质的关系是极显著负相关。对于滨海地区的黏质盐土，大量盐分……