Restoration of minesoil organic matter by cultivation of fiber hemp (Cannabis sativa L.) on lignite post-mining areas

Abstract

We propose here the use of fiber hemp (Cannabis sativa) introduced into post-mining area to be a pioneering plant that can be used for reclamation of the soil degraded by opencast lignite mining. Five years experiment carried out on the total surface of 7.5 ha showed usefulness of hemp as a species used for rebuilding the soil organic matter. By plowing in the whole biomass of cultivated plants it was delivered to the topsoil, accelerating the restoration of the humus layer. Organic matter content of the soil increased from 0.87 % to 2.4 %. In the same time the content of important macroelements like phosphorus, potassium, magnesium and manganese reached the levels above minimum for agricultural soil, while heavy metals (Cu, Zn, Fe) did not exceed an acceptable level.