中子湿度计测定土壤水分的研究

Research on Soil Moisture for Measure of Neutron Moisturemeter

中子湿度计的田间和实验室的校正曲线，两者有差别．不同土壤容重也有差别，但它们呈平行关系．实验室内的校正曲线相关系数为０．９７～０．９９；田间校正曲线相关系数为０．５４～０．９１．中子法与称重法两者在测量土壤水分时，它们之间的相对误差小于８％（容积水分１５％～４５％）．电阻湿度计的相对测量误差小于１０％。称重法的测量误差，在容积水分低于２０％时大于５％：水分低时，误差更大；水分高时，误差变小。

The Calibration curves of neutron hygrometer between field and laboratory were different.Soil bulk density also had an influence on the curves,which showed the parallel straight line relationship.When the calibration curve was done in the laboratory , the correlation coefficient was 0.97～0.99.When in the field,it was 0.54 ～ 0.91.The error betvveen weighing method and neutron method was about 8%(15～45% bulk density moisture).The error of soil moisture measured by resistance meter method was 10%.The accuracy of soil moisture was measured by weighing method.When the soil bulk density moisture was smaller than 20%;its error was greater than 5%. When the moisture was much smaller,its error became greater.While the moisture was higher its error was smaller.