Challenges and opportunities of modelling carbon dioxide sequestration potential in Ukrainian soils

The article examines approaches to modelling carbon dioxide sequestration by soils at different scale levels and describes a number of problems encountered in this process. The main problems in the modelling of organic carbon reserves for the territory of Ukraine have been identified, among which: lack of high-resolution data (hard to access), including types of land use; need for harmonization of existing data; the need for predicative modelling of indicators (clay and organic carbon content) for areas where data are not available; significant amounts of machine time for actual modelling. The need for open access to archived data (technical reports) from large-scale soil surveys 1957-1990 is highlighted. Also, the need to access large-scale topographic data as in the form of scanned topographic maps M 1:10000 and vectorized isolines are substantiated. It is shown that calculations of areas based on rasters in the geographical coordinate system to ensure the same pixel size, regardless of the location within Ukraine, it is proposed to use the “Ukraine Albers conic equal area” projection based on the Datum Pulkovo 1942 for which the error in the lengths of the lines is only 0.1%. Within areas can be used as a proposed projection, as well as precise Gauss-Kruger projections (EPSG 28404-28407, 5565-5583). In this case, it is necessary to take into account the likelihood of finding individual areas in several of the listed zones. It is demonstrated that simulation allows to establish territories in which even the best practices of management do not provide neutralization of emission of organic carbon from soils. However, it is necessary to introduce a priority introduction of adaptive management of the soil resources of agro-landscapes that will contribute to carbon sequestration or minimization of its emission.