ГЕОМЕТРИЯ ЛОКАЛЬНЫХ КОНТУРОВ КАПЕЛЬНОГО УВЛАЖНЕНИЯ ПОЧВЫ, ФОРМИРУЮЩИХСЯ В ЮЖНЫХ ЧЕРНОЗЕМАХ

Abstract

Purpose: to determine empirical dependencies that allow predicting the geometric parameters of local soil moisture contours formed during drip irrigation of southern chernozems. Materials and methods. The empirical basis of the study was the data of experimental measurements of the moisture contour parameters of southern chernozems, formed during drip irrigation, on 10 experimental sites, characterized by: the content of physical clay from 29.0 to 71.1 % of the dry soil mass (DSM), the field moisture capacity from 20.0 to 30.3 % of DSM, soil density from 1.29 to 1.4 t/cub. m. Soil characteristics were studied using the methods of N. A. Kachinsky, “flooded areas” and “cutting ring”. The moisture content of soil samples was determined according to GOST 28268-89. Results. Analytical processing of 10 experimental moisture contour outlines made it possible to obtain a system of empirical dependencies for determining the outline, diameter, horizontal projection area and volume of the local soil moisture contour. Dependencies take into account soil characteristics – the content of physical clay, the field moisture capacity and bulk density, as well as the technological parameters of drip irrigation – dripper consumption, moisture depth, levels of pre-irrigation and post-irrigation soil moisture and irrigation rate. The obtained dependencies were tested on the experimental data of other researchers. As a result, the deviations of the calculated values of the moisture contour diameter from the experimental ones did not exceed 11.3 % and averaged 4.8 %. Forecasting the area of the horizontal projection showed a deviation of the calculation from the experiment on average 8.9 %, and for the volume of the moisture contour – 8.8 %. Conclusions. Empirical dependences that allow predicting the shape, linear, areal and volumetric dimensions of soil moisture contours formed in southern chernozems during drip irrigation have been established. The results of testing help conclude that the proposed dependencies are acceptable for practical use.