TDR法、干烧法及烘干法测定土壤含水量的比较研究

Comparison of soil moisture measurement using TDR method,dry burning method and oven drying method

以第四纪红壤土为研究对象,采用TDR法、干烧法及烘干法3种方法对不同土层深度的不同梯度土壤含水量进行测定,研究结果表明:干烧法测量值接近烘干法,TDR法测量值比烘干法小,TDR法和干烧法绝对偏差和相对偏差随着土层深度的增加而减小;TDR法和干烧法绝对偏差和相对偏差随着土壤含水量增大而减小,土壤含水量在半湿润条件下偏差较大;TDR法、干烧法与烘干法相关性分别为98.7%和96.4%。本研究结果证实,TDR法和烘干法均能较好的反映土壤水分变化规律,TDR法相对烘干法偏小,使用前有必要进行标定以提高精确度。

Taking quaternary red soil as the research object, TDR method, dry burning method and oven drying method were used to determine soil moisture in different gradients of different soil depth. Research results show that： measured value of dry burning method is relatively close to oven drying method, meas- ured value of TDR is smaller than that of oven drying method, the absolute and relative deviations of the TDR method and dry burning method decrease with the increase of soil depth. The absolute deviation and relative deviation of the TDR method and dry burning method decrease with the increase of soil moisture content, and deviation of the soil moisture content is large in semi -humid conditions. The correlation of the TDR method, the dry burning method and oven drying method were 98.7% and 96.4% respectively. The results of this study confirm that TDR method and dry burning method can better reflect the soil water change law, and TDR method is smaller compared with the oven drying method, so it is necessary to cali- brate to improve the accuracy before use.