Effects of simulated acid rain on extractable and leached cations of a lexington silt loam
Titel:
Effects of simulated acid rain on extractable and leached cations of a lexington silt loam
Auteur:
Lilieholm, B. C. Feagley, S. E.
Verschenen in:
Journal of environmental science and health. Part A, Toxic/hazardous substances & environmental engineering
Paginering:
Jaargang 23 (1988) nr. 7 pagina's 669-688
Jaar:
1988-10
Inhoud:
Soil cores were collected to a depth of 15.2 cm from a Lexington silt loam. Simulated precipitation at pH values of 3.7, 4.7, and 5.7 were applied to the soil cores in increments of 500 mL day-1 until volumes approximated 10, 20, 40, and 80 years (14, 28, 56, and 112 L, respectively) of effective rainfall in Louisiana. Extractable cations including K, Ca, Mg, Fe, and Mn were measured from 2.5 cm sections of the soil cores after treatment. The extractable cations were affected by the treatments to a depth of 5.1 to 7.6 cm. The soil surface was depleted of measureable exchangeable Ca and Mg by the leaching solution of pH 3.7 treatment at the 40yr volume of application. The leaching solutions of pH 4.7 and 5.7 depleted the soil of exchangeable Ca and Mg at the 80yr volume. These ions were moved below the zone of increased acidity. The exchangeable K at the soil surface was not removed in significant amounts, but the subsurface K was increased to amounts that were half the control surface K concentrations by the 80yr volume of application. This increase was probably due to released K fixed by clay minerals present such as smectite, mica, and hydrated vermiculite. Extractable Mn was reduced to 0.035 mg kg-1 by the pH 3.7 treatment at the 80yr volume of application. Extractable Fe was not significantly affected by the pH of the leaching solutions at any volume studied.
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