Ranking of acidic soils by priority of liming in the Russian Federation

Excessively acidic soils account for one third of arable land in the Russian Federation (35.1 million ha). Over the post-reform period (1990-2019), the relative share of acidic soils increased by 2%, due to a sharp decrease in the area of liming, and thus restoration of acidic properties of genetically acidic soils previously limed, as well as the involvement in agricultural use of some abandoned fields and fallows covered by acidic soils. This paper demonstrates a new approach to prioritize areas for liming by the example of the Vladimir region. The study makes use of newly established database “Soils of agricultural lands in the Russian Federation” which includes 10,000 soil quality typological unites and 57,678 soil quality mapping units (SQMU). National “Grain equivalent model” calculates the standard yields for grain crops by each SQMU. The GIS analysis allows joining spatial distribution of soil acidity and standard yields of grains in order to determine the priority areas for lime application. Acidic soils with the highest grains standard yield are proposed to be considered as high-priority ones for liming. Application of the given method in two districts of the Vladimir region showed significant reduction in the payback period of liming.