超声波土壤含水量检测装置的模型建立与验证  

Establishment and verification of model for ultrasonic soil water content detector

作　　者：李君[1,2] 徐岩[1] 姜锐[1] 杨洲[1,2] 陆华忠[1,2] Li Jun Xu Van Jiang Rui Yang Zhou Lu Huazhong(College of Engineering, South China Agricultural University, Guangzhou 510642, China Key Laboratory of Key Technology on Agricultural Machine and Equipment, Ministry of Education, Guangzhou 510642, China)

机构地区：[1]华南农业大学工程学院,广州510642 [2]南方农业机械与装备关键技术教育部重点实验室,广州510642

出　　处：《农业工程学报》2017年第13期127-133,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：农业部农业科研创新团队项目(农办人[2015]62号);现代农业产业技术体系建设专项资金(CARS-33-13);广东省岭南水果产业技术体系创新团队建设项目(2016LM1107)

摘　　要：为探究利用超声波脉冲速度检测土壤体积含水量的可行性,以广东省红壤、赤红壤、水稻土为研究对象,设计了一种超声波土壤含水量检测装置,并利用ZBL-U510型非金属超声波检测仪在3种不同温度环境下(10、20、30℃)对不同含水量的土壤样本进行声速测定,构建了土壤体积含水量与超声波差值声速的温度效应数学模型。结果表明:超声波在水稻土中的传播速度比红壤、赤红壤快,且温度对超声波声速随土壤体积含水量变化节律的影响不同。20℃环境下超声波在土壤中的传播速度最快,10℃其次,30℃最慢。采用Richards模型表征土壤体积含水量与超声波差值声速关系的预测误差在3%左右,采用分段结构温度效应模型的预测误差在5%以内,证明该文提出的超声波脉冲速度-土壤体积含水量的温度效应模型可用于动态温度条件下的土壤含水量预测。该研究可为超声波技术在土壤水分检测领域的应用研究提供参考。Soil water content is an important surface variable for describing the soil dryness. Soil water content estimation is used in the monitoring of extreme hydrologic events, weather prediction, irrigation management and water balance modeling. The phenomena of soil moisture expansion, drying shrinkage and bulk density change are obvious in the land-surface hydrological processes. In terms of long-term soil water content monitoring, if only considering the change of mass water content and ignoring the volume-weight change, it will affect the measurement accuracy of soil volumetric water content and information estimation of water movement. Improving the measurement accuracy of soil volumetric water content is conducive to the optimization of irrigation planning and other agricultural practice managements. Ultrasonic pulse velocity sensing can provide a way for nondestructive sensing, which is widely used in the fields of biomedical research, concrete cement concentration detection, and engineering quality assessment. At present, the quantitative effects of soil bulk density on soil water content estimation under different conditions have not been reported in the measurement of soil water content using ultrasonic pulse velocity. The statistical quantitative analysis with the samples of red soil, lateritic red soil and paddy soil from Guangdong Province was carried out in this study. An ultrasonic soil water content detector was developed by using the ZBL-U510 type nonmetal ultrasonic detector. Considering the importance of parametric variation in soil water content in a range of temperature field, under 3 different ambient temperature conditions （10, 20 and 30 ~C）, the effect of soil water content content on ultrasonic velocity was obtained and a mathematical model was established, which represented the relationship between soil water content and differential ultrasonic velocity considering the temperature effect. The equations representing the relationship between ultrasonic velocity and soil volumetric water con

关 键 词：土壤 模型 土壤含水量 超声波脉冲速度 差值声速 

分 类 号：S277.9[农业科学—农业水土工程] TV698.15[农业科学—农业工程]