Modeling process of salt fringe formation during fertigation

Abstract

The introduction of mineral substances into the soil through fertigation ensures the localization of the nutrients necessary for the plant in the area of the root system. However, under certain conditions, this method leads to soil salinization. When the soil dries out, salts are predominantly concentrated at the boundary between dry and wet soil, forming a salt fringe. The article describes the results of experiments and a software tool designed to simulate the process of redistribution of salts during soil drying. The results of calculations for soils of central Russia are presented, taking into account the main hydrophysical characteristics of the soil and the function of hydraulic conductivity under various initial conditions in the form of moisture gradients depending on the depth of the soil, the intensity and duration of irrigation, and the concentration of nutrients. It is shown that by selecting the appropriate initial conditions and irrigation regimes, it is possible to significantly reduce the intensity of the formation of salt fringes.