Dependence of the Vegetation of Winter Crops on the Relief and Soils in the East of the Stavropol Region

Abstract

In total, 7.444 fields with a total area of 857.9 thousand hectares were mapped on the territory of five eastern arid regions of the Stavropol Territory. As of 2021, arable land occupies more than 55% of the study area and is located mainly in its western part. Winter crops occupy 4.693 fields with a total area of more than 487 thousand hectares (56.9% of the total field area). Mapping of the contours of the fields was carried out on the basis of satellite images “Sentinel-2” (“natural colors”). The morphometric characteristics of the fields were calculated on the basis of the SRTM3 DEM. Mask of winter crops for the period 2011–2021 and weekly composites with data on the NDVI value for spring (March–May) were obtained using the Vega-Science service. The areas of the fields identified according to remote sensing data are comparable with official statistics. The fields are located on lands with a steepness of up to 5°, the steepness of 1°–2° prevails (about 90% of the total area). Most fields have a predominant southern exposure, there are no fields with a northern exposure. There are 13 kinds of soils on the territory of the study area, chestnut deep soils predominate. Average NDVI for March–May 2011–2021 It shows the highest values in fields located on meadow soils, the lowest NDVI values are observed on salt flats and salt marshes. It was revealed that the NDVI value decreases with increasing field size, the optimal field size is up to 150 hectares. The highest NDVI values were found in fields with a steepness of 1°–2°, southern exposure and meadow, chestnut and light chestnut soils. The influence of annual precipitation amounts on the NDVI value is analyzed.