Coal ash reclaimed Technogenic soils from the area of Maritsa-Iztok lignite coal basin in Bulgaria were studied for three types of land use, i.e. cereals stubble, acacia and pine vegetated sites. Coal (fly) ash, a waste product from the thermal power plant has been added to the spoils containing geological materials that have been excavated in the process of coal production, since 1970s. Soils were water repellent, but those at the cereals stubble site were characterised by higher hydrophobicity, sandier texture and lower pH. Principle component (PCA) and Cluster analyses (CA) were performed with 16 variables (soil characteristics) with the aim to assess the relationships between the measured parameters and sources of soil water repellency. Four principle components with eigen values 1 containing 38.9, 26.0, 10.7, and 7.5 of the total variance were identified describing 83 of the total variability. The water drop penetration time (WDPT) was significantly positively correlated with C-tot, C-extr, HOC, hygroscopic moisture (HM) and the sand content. Total organic carbon (C-tot) and its fractions, including residual oxidisable carbon (ROC) and the sand content, contribute most significantly to the manifestation of soil water repellency in the studied Technogenic soils.
展开▼
