测定土壤田间持水量的环刀法改进研究

Improvement of Ring-Knife Method for Measuring Field Moisture Capacity

为解决常用的环刀法在干旱半干旱地区测定田间持水量时取样难度大、土样退水速度慢、测定值偏大等问题,对测定过程中的田间采样、砂箱制作、土样浸泡等步骤进行了改进。通过对宁夏58处墒情监测站田间持水量进行实验研究,结果表明,宁夏土壤田间持水量南部偏大、北部较小,土壤干容重变化与田间持水量成反比,测定结果更为合理。

In order to solve the problems in the ring-knife method such as the difficulty of sampling,slow rate of soil dewatering,and the large value of determination in the determination of field moisture capacity in arid and semi-arid areas,the measures of field sampling,the steps of field sampling,sand box making and soil soaking in the process of determination are improved.And the field moisture capacity of 58 moisture monitoring stations in Ningxia is studied experimentally.The results show that the field moisture capacity in southern parts of Ningxia is larger and northern parts is relatively small,and the change of soil dry capacity is inversely proportional to the amount of the field moisture capacity.