摘要
科学使用羧甲基纤维素钠(CMC)实现保水控盐对于滨海壤砂盐碱土改良具有重要意义,而明晰CMC对滨海壤砂土水分运动规律的影响是科学使用CMC的重要基础。为研究施加CMC滨海壤砂土水分运动规律,本文通过开展一维垂直土柱积水入渗试验,探索不同CMC施量(0、0.1、0.2、0.4、0.6 g·kg^(–1))对壤砂土入渗特性、水分分布和土壤水力参数的影响。结果表明,施用CMC土壤的最终累积入渗量增加了4.90%~15.17%、达到预设湿润锋深度的入渗时间增加了61.90%~604.73%;Philip入渗模型参数吸渗率S和Green-Ampt模型参数K_(s)S_(f)均随CMC施量的增加而减少,吸渗率S和平均土壤水扩散率与CMC施量之间的数学关系分别可用二次多项式和指数函数来表示;CMC增强了土壤的持水能力,土壤剖面含水量提高了0.72%~3.74%;CMC通过改变土壤结构影响了土壤水力参数,滞留含水率θ_(r)、饱和含水率θ_(s)及进气吸力倒数α均与CMC施量呈正相关关系,而与饱和导水率K_(s)和形状系数n成反比关系。通过对变异系数CV的分析发现,CMC对饱和导水率K_(s)和进气吸力倒数α影响表现为中等差异,对滞留含水率θ_(r)、饱和含水率θ_(s)和形状系数n表现为弱差异。研究结果揭示了CMC对滨海壤砂土减渗保水的内在机理,为滨海盐碱地的改良提供了理论参考。
【Objective】Scientific use of sodium carboxymethyl cellulose(CMC)to achieve water conservation and salt control is of great significance for the improvement of coastal sandy saline-alkali soil.It is therefore important to clarify the influence of CMC on the water movement law of coastal soil sand by evaluating the effect of CMC concentration on soil hydraulic parameters.【Method】In this study,a one-dimensional vertical infiltration experiment was carried out to study the effects of different CMC application amounts(0,0.1,0.2,0.4,0.6 g·kg^(–1))on the infiltration characteristics,water distribution,and soil hydraulic parameters.【Result】The results showed that the final cumulative infiltration increased by 4.90%-15.17%,and the infiltration time to reach the preset wetting front depth increased by 61.90%-604.73%with the increase of CMC application.The adsorptivity S in the Philip infiltration model decreased from 0.685 cm·min^(-0.5) to 0.256 cm·min^(-0.5) and the parameter K_(s)S_(f) in the Green-Ampt model decreased from 0.633 cm^(2)·min^(-1) to 0.096 cm^(2)·min^(-1) with CMC application.The S and the average soil water diffusivity could be described by a quadratic polynomial and exponential function,respectively.Soil water content increased by 0.7%-3.7%because CMC enhanced the soil water holding capacity.Additionally,the retention water contentθ_(r),saturated water contentθ_(s),and air-entryαreciprocal were positively correlated with the amount of CMC,and inversely proportional to the saturated water conductivity K_(s) and shape coefficient n.CMC induced a moderate variation to K_(s) andα,and a minor variation toθ_(r),θ_(s),and n.【Conclusion】This study can provide a valuable theoretical reference for rational use of CMC for the improvement of coastal saline-alkali soil.
作者
单鱼洋
马晨光
王全九
李晓菊
陶汪海
张继红
苏李君
曹玲
SHAN Yuyang;MA Chenguang;WANG Quanjiu;LI Xiaoju;TAO Wanghai;ZHANG Jihong;SU Lijun;CAO Ling(State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China,Xi’an University of Technology,Xi’an 710048,China;Shaanxi Fengxi Xincheng Investment Development Co.,Ltd,Xi’an 710000,China)
出处
《土壤学报》
CAS
CSCD
北大核心
2022年第5期1349-1358,共10页
Acta Pedologica Sinica
基金
国家自然基金山东联合基金(U1706211)
国家自然科学基金项目(41830754,51979220,41907010)资助。
关键词
羧甲基纤维素钠
土壤入渗
水分分布
水力参数
Sodium carboxymethyl cellulose
Soil infiltration
Water distribution
Hydraulic parameters
