Abstract:
The blends of coal combustion by-products (CCBs) with organic wastes
(sewage sludge and spent mushroom compost) were investigated for
elaboration of soil substitutes for land rehabilitation of coal mine
affected areas. The study incudes four types four types of habitat with
different water retention and fertility i.e.: dry and moderate fertility
(A1-A3), mesic and low fertility (B1-B3), mesic and moderate fertility
(C1-C3), humid and low fertility (D1-D3).
Obtained results revealed that the amounts of macronutrients were
sufficient for supporting plant growth i.e.: N (0.44-0.60 %), P
(0.13-021 %), K (1.63-1.98 %), Mg (1.01-1.38 %), Ca (5.32-8.23 %), S
(2.66-4.12 %), whereas the concentration of organic matter varied
within the range 20.3-27.9 %. Phytotest using white mustard
(Sinapis alba ) seeds under laboratory conditions showed that the
best results of sprouting i.e: 56 and 66 % were obtained for D2 and D3,
respectively. The values of pH (8.16-8.78) and electrical conductivity
(5.28-6.73 mS·cm-1) of tested soil substitutes were
found to be the decisive factors limiting the germination process. The
coefficients between the parameters of soil substitutes and theSinapis alba sproutings have revealed negative correlation with
electrical conductivity (r = -0.46). Additionally, tests with meadow
vegetation gave promising opportunity for the use of soil substitutes in
the process of land rehabilitation. The cover of the mesic and dry
meadow vegetation reached 90%. The Principal Component Analysis (PCA)
has outlined that pH, content of P and organic matter, are the most
important factors that influence cover of meadow vegetation.
Keywords: Coal mining by-products; Artificial soils; Spoil
tips; Land rehabilitation; Germination