V. Tsolova, M. Banov

Abstract. The paper deals with the characterization of organic matter in reclaimed Technosols (WRS, 2007) built in the different mine regions of Bulgaria (Chukurovo, Pernik, Maritsa-Iztok and Lokorsko). The studied soils were formed around 30 years ago through the humus and none humus reclamation methods. The humus formation processes occur with greater intensity in reclaimed without humus technogenic soils and form the vertical differentiation of the section. The newly formed organic horizons contain mainly non-extractable (unreachable) carbon, formed due to the coal impurities and / or on-going evolution of the geological materials, building up the technogenic soils. The extractable carbon, which content averages at about 0.22%, is represented by humic acids with low condensation and maturity. The process of cultivation of the Technosols occurs along with the increasing content of fulvic acids, which decreases the stability and quality of the organic matter, especially in the humus reclaimed Technosols.