M. Banov*, V. Tzolova, I. Kirilov

N. Poushkarov Institute of Soil Science, Agrotechnologies and Plant Protection, 1080 Sofia, Bulgaria (Manuscript received 4 July 2017; accepted for publication 18 October 2017)

Abstract. Samples of geological materials, used for reclamation of land, disturbed by open coal mining have been investigated. The obtained results for the opportunities of biological regeneration of the lands fertility, reclaimed with these materials, put them in the following order: Pliocene clays from the region of Maritza Iztok (the biggest energy complex with the largest open coal mine in Bulgaria); marl materials from the area of the town of Pernik; and last – sulfur containing materials from the region of Chukurovo Mine, Sofia region. It is proposed that the period for biological reclamation, shown in Article 4, item 2 §(а) from Regulation No. 26/1996 for reclamation of disturbed areas, improvement of lands of low productivity, removal and utilization of the humus layer, must be changed from”5years”to”7-12years”for the lands reclaimed without humus and to”3-5years”for the lands reclaimed with of humus horizon used.