中子水分仪在棉田土壤上的标定研究

Calibration of neutron probe in the soil of cotton field

通过对中子水分仪在棉田土壤中的标定研究 ,提出了用系统聚类法选择中子水分仪标定管点的方法 ;得到土壤不同深度层次的 3条标定直线 :0 cm～ 2 5 cm土层标定直线的截距和斜率是 1.81× 10 - 2 cm3/ cm3,2 3.4 1×10 - 2 cm3/ cm3;30 cm～ 80 cm土层标定直线的截距和斜率是 - 2 .77× 10 - 2 cm3/ cm3,2 6 .2 5× 10 - 2 cm3/ cm3;90 cm～110 cm土层标定直线的截距和斜率是 - 6 .6 2× 10 - 2 cm3/ cm3,2 8.6 0× 10 - 2 cm3/ cm3。

Field calibration of neutron probe in the cotton field soil was studied using the sampling method and the hierachical clustering methods for selecting the calibration sites. The results showed that the slops and intercepts of three calibration equations were 23.41 ×10 -2 cm 3/cm 3 and 1.81 ×10 -2 cm 3/cm 3 in 0 cm^25 cm soil layer, 26.25 ×10 -2 cm 3/cm 3 and -2.77×10 -2 cm 3/cm 3 in 30 cm^80 cm soil layer, 28.60 ×10 -2 cm 3/cm 3 and -6.62×10 -2 cm 3/cm 3 in 90 cm^110 cm soil layer. It was also proved that it was important to use precise calibration equation for irrigation scheme with neutron probe.