两种园林用FDR土壤水分传感器的精度校正

Accuracy calibration of two FDR soil moisture sensors used in urban landscape

利用质地差异较大的园土及草炭∶陶粒∶园土=3∶1∶1（体积比）的混合基质对2种土壤水分频域反射仪（FDR）进行了室内标定.结果显示,在目前园林应用的测量精度内,土壤质地对两种FDR土壤水分传感器的测量影响不显著,但FDR测量值较烘干法明显偏高,校正斜率介于0.68～0.70之间.相关分析表明FDR测量值与真实值之间有极显著的相关性,相关系数大于0.97.利用获得的线性函数进行校正,校正后的土壤水分值与采用传统的烘干称重法测得的值相符.基于以上结果,FDR土壤水分传感器能准确、快速测定土壤含水量,在城市园林节水灌溉管理中发挥重要作用.

In this study two FDR soil moisture sensors were calibrated using two different types of medium,garden soils and mixed medium composed ofpeat,ceramisite,and garden soil in a 3 ∶ 1 ∶ 1 ratio （volumetric rate）.The results showed in the requiredrange of measurement accuracy,the measurement result using FDR soil moisture sensors was not affected by soil texture,however the value was greater than the actual soil water content obtained through drying method.And it was found that there was a significant linear relationship between measured and actual water content relationship with the correlation coefficient exceeding 0.97,and the slope was between 0.68-0.70.After calibrated though this mathematical function,the measured value obtained using FDRsoil moisture sensor,agreed well with the actual water content.Based on the above results,FDR soil moisture sensor can measure the soil water content exactly and rapidly,playingan important role in the water conservation of urban landscape irrigation management.