Аннотация:Abstract—Soil resources are natural strategic resources and national wealth. Stavropol Krai is an importantagricultural region of Russia, which produces 8% of grain, 4% of sunflower, 5% of sugar beet, 1% of fruits andberries, 3% of meat and 2% of dairy products. It is necessary to examine the lands of the Stavropol Krai, inorder to consider the main directions of strategic land management in facing the challenge of sustainabledevelopment of agricultural environmental management. The object of the study is a field with a total area of241 ha, located in the dry zone—northern part of Stavropol Krai, the contours of the field completely lie inthe area the predominant black soil contour (Calcic Kastanozem). The land management was the rotation ofwinter wheat with fallow. Arable horizon of black soils sampling was carried out on a square grid with a stepof 100 m. According to the soil organic matter (SOM) content in the studied field, there is a progradation, therevealed degradation of pHKCl belongs to the 1st and 2nd degrees of degradation. Research has shown thattaking the spatial variation of soil properties into account it is possible to determine the degree of soil propertiesindicators worsening in space within a field, herewith, it is insufficient to consider soil properties worseringor improving only by comparing average values. We compare the two approaches using pHKCl indicator:(1) comparing the average value with the reference—Kastanozems of the Ciscaucasia zone, (2) comparing theinterpolated data using the ordinary kriging; and then calculate the relative amount of investment for improvingsoil properties. The investments when comparing the average value with the reference—Kastanozems ofthe Ciscaucasia zone, three times higher than investments considering natural variation of soil properties inspace by interpolated kriging data. Our example showed that there is uncertainty in determining the qualityof land due to the natural variation of soil properties in space: in the natural environment, everything isunevenly distributed; any soil property has variation within one soil contour in agricultural systems, thereforeto consider soil degradation by comparing average values allows to improve the estimates.Keywords: map of soil properties, Calcic Kastanozem, ordinary kriging, reference values, soil fertility model
