PECULIARITIES OF SALT MOVEMENT IN THE PROFILE OF RECLAIMED ALKALINE BARABA

Abstract

The experiment on the crust black alkali was conducted in the microplot trial which was started in 1986 in the controlling variant with no gypsum, 45 t/ha plaster and 56 t/ha gypsum. The trial was in the gypsum bed since 1996. The researchers continued observing the level of the bed, mineralization of the ground waters and salt concentration in the soil in 2006-2015. The ground waters were 45 sm deep when establishing the trial; in 1987 they deeped to 120 sm and 233-266 sm in the period 1988-2012. This related with their dynamics and climate conditions. In the first years, the gypsum had an impact on sodium cations exchange with calcium cations of ameliorant in the soil. This contributed to significant increasing of concentration of soluble saline and sodium sulfates that moved to the ground waters. The next years the authors observed desalinization of reclaimed black alkali. The significant and urgent groundwater surge (up to 50 sm) in 2013 influenced the soil salinization and increased the concentration of bicarbonates, carbonates especially sodium carbonates that resulted in additional salinization of the reclaimed black alkali. In spring there was a slight desalinization whereas salt concentration was increased in autumn.