INSTRUMENTAL COLUMN-CENTRIFUGAL METHOD OF ESTIMATING WATER-HOLDING CAPACITY OF SOIL AND GROUND
A new instrumental method for express evaluation of the capillary-sorption capacity of soils as a function of humidity, the essence of which is to use a centrifugal field to increase the outflow of gravitational water in the distribution of samples in the form of soil columns. In contrast to the classical method of high columns, the use of centrifugal force, increasing the effect on soil moisture gravitational factor, reduces the height of specimens from several meters to the characteristic size of the centrifuge tubes (10 cm). Compared to the previously proposed method of equilibrium centrifugation, this method allows us to obtain almost continuous water-retentive curve after rotation of the soil columns by 1-2 stages of the experiment with a constant number of revolutions of the centrifuge. Development is easy to use, high accuracy and reliability in obtaining the dependence of capillary-moisture sorption capacity of its content in soil in a wide range of full field capacity to wilting point moisture. Method, in essence, simulates the really existing in the soils of the process of distribution of moisture in the soil profile after gravity drainage (to achieve field capacity) and its results can be used for information and settings of modern soil hydro-physical models such as HYDRUS.