Assessment of Drilling Waste Addition on the Salinity of Soils and Growth of Selected Grass Species

The soils that sustained damage from the mining industry are threatened with high salinity. The aim of the research involved assessing the impact of drilling wastes on the salinity of soils, and the influence of salinity on the germination and growth of various grass species. The research involved the energy, germination capacity and growth of four grass species: tall fescue Festuca arundinacea (cv. Odys), red fescue Festuca rubra (cv. Areta), perennial ryegrass Lolium perenne (cv. Gazon) and smooth meadow grass Poa pratensis (cv. Alicja) in the soils with various amount of drilling wastes addition and different salinity. The drilling waste addition in the amount of 5%, 10%, 15%, 20%, 30% (v/v) (pH=4.1, EC=8.84 µS/cm) significantly increased the salinity of the prepared mixtures to the levels of >2.5 dS/m, determined as harmful for most plants. Studies indicated that 5%, 10% and 15% (v/v) drill cuttings addition does not inhibit the growth of the considered grasses, while at the 25% addition of drill cuttings, the length of seedlings and roots is halved in comparison to the control sample without drilling waste addition. The mixture with 30% drilling waste addition, characterized by the salinity of 18 dS/m, inhibits the growth of all considered plant species. The conducted discrimination analysis indicated that cv. Gazon and cv. Odys differ from the other considered grass species, exhibiting the highest resistance to salinity caused by drilling waste addition. In turn, cv. Alicja was characterized by the lowest tolerance to salinity.