Abstract
The surface exploitation of mineral raw materials inevitably changes the environment, thus resulting in soil degradation. This paper presents the results of growing sudangrass (Sorghum sudanense Pers.) in the reclaimed Deposol (technosols) in the Stanari Coal Mine area. Green manuring was the cultural practice used for sudangrass growing and land reclamation. The purpose of this research is to increase the amount of organic matter in the Deposol surface layer. The research was performed within a two-year period (2009-2010) at the experimental (technosol) site of the Stanari Coal Mine, located on the inside part of the overburden deposition site, near the Raskovac pit. The research of green manuring included a two-factor experiment with four replications. Two cultivars of sudangrass (Factor A) were used with three fertilization treatments (Factor B). The soil analyses indicated a sandy and low fertile soil. The experimental plot Deposol showed favorable physical properties, whereas its chemical and biological properties proved very unfavourable. The highest yield of biomass (29.15 t ha-1), as well as the dry matter (10.30 t ha-1), was recorded in the cultivar ‘Piper Sweet’ (in 2009), which was completely treated with mineral fertilizers. The lowest yields of biomass (2.05 t ha-1) and dry matter (0.95 t ha-1) were observed in the cultivar ‘Srem’ in 2010. Statistically significant differences were found between the treatments applied, emphasizing that only certain cultivars of sudangrass and types of fertilization (encompassing reasonably high amounts of nitrogen) can significantly increase the amount of organic matter in Deposol.