Goal. To establish the patterns of influence of different doses of gypsum on salt and physicochemical parameters of dark-chestnut weakly alkaline soil (pH, content of water-soluble salts, and absorbed cations) and the degree of their heterogeneity. Methods. Field — to study the effect of gypsum on the properties of dark-chestnut soil, laboratory analytical — to determine salt and physicochemical parameters, mathematical and statistical — to assess the reliability of research results. Results. The application of calcium ameliorant (gypsum) caused a decrease in the reaction of the soil solution by 0.5 – 0.7 pH units, as well as desalination of the soil in absolute and relative alkalinity. There were no changes in the content of toxic salts in the soil. The variegation of the soil in terms of water pH tended to decrease and was weak before and after the experiment. Gypsum reduced the degree of heterogeneity of both alkalinity indicators to weak (reduction of coefficients of variation from 12.01 to 7.29% and from 11.97 to 6.94%), but the differentiation of gypsum application doses did not help to equalize the alkalinity of dark-chestnut soil compared to the variants, where the improver was applied evenly. Conclusions. The soil in the variants with average maximum and differentiated levels of gypsum application passed into the category of non-alkaline. According to the effect of desalination, the options with average and differentiated levels of gypsum application were almost the same. However, the average dose of gypsum in the variant with a differentiated level of application was 0.86 t/ha less. The alkalinity indicators in the variants with the minimum and maximum levels of gypsum application were most equalized. Differentiation of gypsum application doses in comparison with variants of its uniform application did not affect the degree of heterogeneity of alkalinity indicators of dark-chestnut soil.