Tuesday, November 6, 2007
211-9
Aggregate Stability of Reclaimed Minesoils vs. Native Soil.
Restoring mine sites after major surface mining operations involves reclamation to restore soil functions within the landscape. The concept of soil quality links soil properties to the ability of the soil to support ecological systems. Aggregate stability is an early indicator of improved soil quality and can be used to evaluate progress of soil restoration activities. Aggregate stability affects soil erosion potential, hydrology, and productivity. As mine soils develop aggregates, stability of the reclaimed minesoil and the development of the soil profile may occur in concert. The objective of this study was to compare the spatial variability of aggregate stability and soil structure of a reclaimed mine soil after five years of reclamation when compared to two native soils (one burned in a recent forest fire, NB, and one unburned, NUB). Spatial distribution of aggregate stability after five years was analyzed. Aggregate stability was evaluated for the two reclaimed mine soils (R1, R2) and two native soils (NB, NUB) using a wet sieving method on 1-2 mm aggregates. Soil structure was visually observed for the soils with the aid of a Natural Resource Conservation Service field book. Two native soils (NB and NUB) showed significantly different aggregate stabilities. The NB, R1, and R2 soils had similar aggregate stability. Aggregate stability was significantly stronger in the NUB soil when compared to the NB soil. All the soil profiles of NB, R1, and R2 soils had granular structure in the top horizon (A) and weak or moderate subangular blocky structure in the subsequent horizons (B). R2 soil had stronger structure development than R1 soil. The NUB soil structure was granular to platy in the A horizon, subangular blocky parting to platy in the E horizon, and subangular blocky in the lower EB horizons.
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