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Leaching from Organic Matter–Rich Soils by Rain of Different Qualities
Author(s) -
Strand L. T.,
Abrahamsen G.,
Stuanes A. O.
Publication year - 2002
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/jeq2002.5470
Subject(s) - lysimeter , leachate , leaching (pedology) , acid rain , dissolved organic carbon , environmental chemistry , sulfate , chemistry , soil water , organic matter , calluna , nitrate , mesocosm , lessivage , total organic carbon , soil ph , environmental science , moorland , soil science , nutrient , ecology , organic chemistry , biology
Soil monoliths from an area exposed to acid precipitation and from an unpolluted area were used in a lysimeter experiment to study effects of different rain qualities on the chemical composition of the leachate from shallow soils rich in organic matter. The vegetation was either dominated by moorgrass [ Molinia caerulea (L.) Moench] or heather [ Calluna vulgaris (L.) Hull]. The lysimeters received either “acid rain” (pH 4.3) or “normal rain” (pH 5.3). High concentrations of dissolved organic carbon (DOC) were characteristic of the leachate. The different “rain” qualities had no significant influence on the DOC concentration. More DOC was, however, leached from lysimeters with heather vegetation. Roughly 50% of the aluminum (Al) was in complex with organic material and the Al charge was calculated to be between +1.4 and +2.0. Sulfate (SO 2− 4 ) was the only component that was significantly influenced by the treatment, as more was leached from lysimeters receiving “acid rain.” Sulfate was poorly correlated with pH, suggesting that reduced SO 2− 4 input would not necessarily lead to reduced acidity. Differences in the pH of the leachate due to the treatments were less than 0.15 pH units. Nitrate (NO − 3 ) was only leached in very low concentrations and of little consequence for the leachate acidity. Some observations do, however, suggest that NO − 3 may contribute to acidification in episodes with high precipitation. High concentrations of Cl − in the leachate and a significant positive correlation between Cl − , H + , and base cations indicate that sea salt episodes may be important for soil acidification and acidity of the leachate.