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Potassium and Magnesium Availability in Mudstone Coal Overburdens in West Virginia
Author(s) -
Gensheimer G. J.,
Stout W. L.
Publication year - 1982
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1982.00472425001100020015x
Subject(s) - soil water , gypsum , chemistry , potassium , ammonium acetate , silt , calcite , environmental chemistry , weathering , peat , magnesium , sedimentary rock , mineralogy , geology , soil science , geochemistry , ecology , paleontology , high performance liquid chromatography , organic chemistry , chromatography , biology
Mudstones are rapidly weathering sedimentary rocks with a hardness of <2.5 (gypsum = 2.0, calcite = 3.0) and are dominated by silt‐and/or clay‐sized particles. They may contain abundant amounts of Ca, Mg, and K, and may have a high neutralizing potential. Mixing mudstones containing high amounts of K and Mg with infertile top‐soils when reclaiming surface mined lands may increase the fertility of the resulting mine soil. The objective of this experiment was to determine which soil testing procedure(s) would best predict the availability of K and Mg to plants from nine mudstone samples associated with seven coal seams in northern West Virginia. The soil testing procedures used to extract K and Mg from the mudstones were double acid (0.05 N HCl and 0.025 N H 2 SO 4 ), boiling 1 N HNO 3 (nitric acid), neutral 1 N NH 4 OAC (ammonium acetate), water, and Baker's small exchange method. The biological extraction of K and Mg by oat seedlings ( Avena sativa L.) was determined with a modified Stanford‐DeMent procedure. Except in mudstones where toxic elements are present, such as the Clarksburg samples, it appears that mudstones are a possible source of plant‐available K in newly constructed mine soils. The HNO 3 , NH 4 OAC, and Baker tests predicted the relative availability of K in the mudstones. The HNO 3 test was best able to predict the total amount of K available to the oat seedlings. Although there was a large amount of HNO 3 ‐extractable Mg in the high‐pH mudstones, it was not available to the oat seedlings. If, as postulated, the Mg in these mudstones was in the carbonate form, it may become available over time in the humid regions where the mudstones occur.