中子仪测定苜蓿田土壤含水量的标定研究

Calibration study of the determination of alfalfa soil moisture with neutron probe

通过一次安装,免灌水,点聚图资料筛选和对容积含水率三点平滑的一套标定方法,应用中子仪对苜蓿田土壤含水量的标定进行了研究,得到了土壤不同深度的三条标定直线:20～60 cm土层标定直线为y=82.772x-3.007(R2=0.9353,R=0.9671);60～120 cm土层标定直线为y=77.822x+0.1032(R2=0.8283,R=0.9101);120～200 cm土层标定直线为y=83.327x-2.2304(R2=0.8871,R=0.9419)。中子仪法相对于土钻法所得含水量的平均相对误差为0.81%,说明所得标定方程精度较高,完全可以用中子仪法代替土钻法测定土壤含水量。

From the calibration study of the determination of alfalfa soil moisture with neutron probe, we got three calibration equations, which were y = 82. 772x - 3. 007 （ R^2= 0. 9353, R = 0. 9671 ） for 20 - 60 cm soil layer, y = 77. 822x ＋ 0. 1032 （ R^2 = 0. 8283, R = 0. 9101 ） for 60- 120 cm soil layer, and y = 83. 327x - 2. 2304（ R^2 = 0. 8871, R = 0. 9419） for 120-200 cm soil layer. Average relative error of neutron probe method was 0.81% in comparison with oven drying method. This proved that it was feasible to determination soil moisture with neutron probe instead of oven drying method.