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Experimental Soil Acidification and Recovery at the Bear Brook Watershed in Maine
Author(s) -
Rustad L. E.,
Fernandez I. J.,
David M. B.,
Mitchell M. J.,
Nadelhoffer K. J.,
Fuller R. B.
Publication year - 1996
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1996.03615995006000060045x
Subject(s) - soil water , lysimeter , soil horizon , chemistry , watershed , acid neutralizing capacity , environmental science , environmental chemistry , hydrology (agriculture) , soil science , geology , acid deposition , geotechnical engineering , machine learning , computer science
The response and subsequent recovery of soils (Typic Haplorthods) to acidification by dilute H 2 SO 4 (2000 and 4000 mol c ha −1 yr −1 of SO 4 ), HNO 3 (2000 and 4000 mol c ha −1 yr −1 of NO 3 ), and combined H 2 SO 4 ‐HNO 3 (2000 mol c ha −1 yr −1 each of SO 4 and NO 3 ) were studied at the Bear Brook Watershed in Maine. Treatments were delivered to eighteen 15 by 15 m plots (three plots per treatment) during four field seasons from 1988–1991. Recovery was monitored for the ensuing two years. Changes in soil and soil solution chemistry were evaluated using tension lysimeters and buried mineral soil bags. Soil solutions responded rapidly to all treatments with increased concentrations of SO 4 (four to eight times ambient) and NO 3 (39 to 88 times ambient), depending on treatment, accompanied by increased concentrations of Ca and Mg (three to five times ambient) from the upper B horizon. As solutions passed through the upper 25 cm of the pedon, concentrations of SO 4 and the sum of base cations decreased significantly. Results from buried mineral soil bags located directly below the forest floor indicated that a relatively reversible SO 4 sorption mechanism was responsible for attenuating most SO 4 losses from these soils. Following 4 yr of acid inputs and 2 yr of recovery, soil and soil solution chemistry were remarkably unchanged, demonstrating that this hardwood forest soil was not irreversibly altered and could quickly recover.