A comparison of methods for measuring soil moisture characteristic curve

摘要

Accurate soil water flow modeling is not possible without a corrected soil moisture characteristic curve. At present, the curve is determined by 4 popular methods namely tension disc infiltrometer, Beerkan method, evaporation and pedo-transfer function. Since these 4 methods have never been compared therefore this study compares the accuracy and advantage among the methods. The soils located in a para rubber plantation in Phra Yun District, Khon Kaen Province were chosen for the comparison. We found that the Beerkan and the evaporation gave reasonable and consistant results, while the tension disc infiltrometer gave too low the negative pressure head (NPH) and the pedo-transfer function gave too high NPH values. However, the Beerkan is simpler and cheaper than the evaporation.