Properties of degraded and reclaimed soils in the area of the abandoned “Jeziórko” sulfur mine (Poland)

The aim of the study was to determine some physicochemical and chemical properties of post-mining soils reclaimed in different directions, after completed sulfur exploitation by means of the borehole (Frash) method. The study was conducted in 2013 in the former Sulfur Mine „Jeziórko” located on the Tarnobrzeg Plain between Tarnobrzeg and Stalowa Wola cities (Podkarpackie Voivodeship, south Poland). It covered an area of land reclaimed as the arable or forest land. The most important problems connected with sulfur exploitation was the occurrence of a layer of solid sulfur which was previously removed. During the reclamation process, embankments and excavations were leveled through replenishing large amounts of ground, post-flotation lime, mineral fertilizers, and sewage sludge. Moreover, studies upon degraded and non-reclaimed area (by 2013) were also carried out. Examined land was characterized by granulometric composition of sands, loamy sands, and sandy loams. Re-leveling of degraded land using post-flotation lime contributed to lower levels of acidification of reclaimed soil surface. The highest contents of organic carbon and total nitrogen were found in the surface layers of the soils studied. Content of available potassium ranged from very low to average. The soils were characterized by a high content of available magnesium in the surface layers of the profiles (maximum 71.8 mg·kg−1 in soil reclaimed as forest land), while below the Mg content was usually low. Contents of individual exchangeable cations could be lined up in a following decreasing sequence: Ca2+>Na+>K+>Mg2+ Referring to the topsoil, reclaimed soils were characterized by more favorable properties (pH close to neutral, lower acidity, higher sorption capacity, higher organic carbon, total nitrogen, and available forms of phosphorus, potassium, and magnesium concentrations) as compared to non-reclaimed soil