The aim of the research was to study the precipitation impact on the formation of a horizon of ready soluble salts and gypsum in ordinary carbonated chernozems of warm South European facies, according to the Soil Classification of Russia (2004) – migrative segregative chernozems. Full-depth profile pits were laid on different relief features. Mathematical and statistical methods to calculate the medium automorphic soils profile wetted depths were used, taking into account the one-time inflow of average annual atmospheric precipitation on the day surface, using data (from 1948 to 1980) on the average long-term wetted depth of ordinary carbonated chernozems profile formed on the territories of Neklinovskiy, Matveyev-Kurgan, Kuibyshev, Rodionov-Nesvetayskiy, Azov, Zernograd, Egorlykskiy and Tselinskiy districts of Rostov region. The comparative analysis of the actual long-term and calculated wetted depths of the ordinary carbonated chernozems of the Lower Don has been carried out. The calculation showed that the wetted depth will be 192 cm at field soil moisture corresponding to the maximum molecular moisture capacity and the assumption of a one-time precipitation infiltration in the volume corresponding to the annual rate. In the considered areas of Rostov Region, up to 71 % of precipitation on the day surface is percolated to a depth of 80 to 159 cm. It is an evidence of the relict nature of soil horizon of accumulation of readily soluble salts and gypsum, located at a depth of 210–250 cm, and it is a proof of the absence of link with modern chernozem soil profile. At present, groundwater lies at a depth of about 6 m and more, depending on the relief, so the gypsum formation can’t be associated with modern groundwater. But if we take into account that the ancient ground waters were higher than the modern ones, then, proceeding from the mineral composition of artesian waters, one can also draw a conclusion on the possible relict origin of the of ready soluble salts and gypsum horizon.
Key words: ordinary carbonated chernozems, carbonated new formations, white-soft spot, gypsum.
DOI: 10.31774/2222-1816-2018-3-121-131
For citas:
I. V. Morozov, E. N. Minaeva, O. S. Bezuglova On Formation of Gypsiferous Horizon in Ordinary Carbonated Chernozems. Scientific Journal of Russian Scientific Research Institute of Land Improvement Problems. 2018. No 3. P. 121-131 DOI: https://doi.org/10.31774/2222-1816-2018-3-121-131
