LAUSR

Modern technologies make it possible to obtain a lot of diverse information about the soil properties using satellite images, but field studies are also required to create or refine digital soil maps. To create a digital soil map scaled 1:25 000 in 2016, a classical field study was conducted with the laying of soil sections in places with the same coordinates as in the mapping of 1982. It allowed to carry out retrospective monitoring of transformation of morphogenetic and agrochemical properties of soils of the southern forest-steppe of the Republic of Bashkortostan (Russia) for the 34-year period of farm use. Thus, the correction and digitization of the soil map allowed to establish that arable land occupies 69.792 ha (67.9%) in the structure of agricultural land (102 811 ha). The monitoring showed deterioration of the main characteristics of arable soil fertility: the diminishing of humus-accumulative horizons, significant decrease of humus content (p ≤ 0.05), a small but reliable acidification of the medium reaction and reducing labile phosphorus. Losses of organic matter occurred mainly in the most fertile soils; their proportion decreased from 55.9% of the total area of agricultural land to 12.4%.