A NEW, SIMPLE, AND RAPID METHOD FOR DETERMINING THE MOISTURE EQUIVALENT OF SOILS, AND THE ROLE OF SOIL COLLOIDS ON THIS MOISTURE EQUIVALENT

Abstract

The principle of this new method is based upon the pulling of water from the soil by vacuum pressure forces instead of by centrifugal forces. The method is simple, rapid, accurate, reliable, and infinitely more available than the centrifugal method. The results obtained show that there is a remarkably close relationship between the moisture equivalent and the colloidal content of soils as determined by the hydrometer method. There is, however, no relationship between coarse silt and sand and the moisture equivalent. It is shown that the moisture equivalent or comparative moisture holding powers of the different soils can be indirectly determined by the hydrometer method and that the method also may be used to obtain "single value" factors for summarizing the various physical properties of soils.