时域传输技术测定盐土含水量的应用研究  

Performance of time domain transmission measuring soil water content in several non-saline soils and saline soil

作　　者：郑茹梅[1] 李子忠[1] 龚元石[1] 

机构地区：[1]中国农业大学资源与环境学院,北京100193

出　　处：《中国农业大学学报》2010年第2期18-23,共6页Journal of China Agricultural University

基　　金：国家"863"计划项目(2006AA10Z264)

摘　　要：为检测所研制的时域传输仪(ti me domain transmission,TDT)测定土壤含水量的性能,通过室内土柱试验,对时域传输仪在3种质地非盐土和滨海盐土上测定土壤含水量的性能进行了评估。结果表明:在一般非盐化的农业土壤和滨海盐土上,土壤体积含水量和TDT输出的电压之间均存在线性关系。在砂土和砂壤土上,可以忽略质地差异和容重因素的影响用统一关系式计算含水量,估计标准误差是0.017cm3/cm3;在壤黏土上容重因素影响明显,应用时需要单独校正,校正后计算含水量的估计标准误差小于0.016cm3/cm3。TDT水分测试仪在盐溶液中浸入深度和输出的电压值始终保持线性关系,且不受溶液电导率的影响。在滨海盐土上,不同容重条件下土壤体积含水量和TDT输出的电压均呈线性关系,且容重因素影响不明显,可以建立统一的含水量校正关系,估计标准误差是0.019cm3/cm3。因此,TDT水分测试仪可以测定一般农业土壤含水量,在盐溶液中具有抗盐分干扰的优良特性,在滨海盐土含水量的测定上也具有很好的适用性。The objective of the paper is to test the performance of self-developed time domain transmission（TDT）measuring soil water content.A laboratory experiment was conducted in sand soil,sandy loam soil,loamy clay soil and coastal saline soil.Results showed that there was a linear relationship between soil volumetric water content and TDT voltage output for non-saline agricultural soils and coastal saline soils.For sand and sandy loam soils,a universal relationship could be established to estimate soil water content when ignoring the effect of soil texture and bulk density,and the standard error of the estimate was 0.017 cm3/cm3.However,the influence of bulk density on calibration relationship was significant for loamy clay soil,the individual calibration was required and the standard error of the estimate was less than 0.016 cm3/cm3.In salt solution,there was a linear relationship between the TDT output voltage and the depth of immersed in salt solution,and the effect of electrical conductivity of solution was not significant.For coastal saline soils,the linear relationships between soil volumetric water content and TDT voltage output were established with different bulk densities,but the effect of bulk density was not obvious.Thus,a universal relationship could be established to estimate saline soil water content and the standard error of the estimate was 0.019 cm3/cm3.It was indicated that TDT instrument could measure soil water content accurately for agricultural soils.It has good characteristic of high-salt tolerance in salt solution and can be used to measure saline soil water content.

关 键 词：土壤含水量 时域传输 盐溶液 盐土 

分 类 号：S152[农业科学—土壤学]