Aggregate Stability of an Eroded and Desurfaced Typic Argiustoll
1991
Gollany, H. T. | Schumacher, T. E. | Evenson, P. D. | Lindstrom, M. J. | Lemme, G. D.
Aggregate stability is a measure of the ability of soil to withstand the disrupting forces of rain and nonsymmetrical wetting. Erosion may influence aggregate stability by exposing soil with properties different than the original soil surface. This study was conducted to determine: (i) the influence of antecedent soil water content on wet aggregate stability using aggregates prehumidified to near saturation; (ii) the effects of organic C and clay content on the soil water content-aggregate stability relationship; and (iii) the effect of topsoil removal on aggregate stability. Seventy-eight soil samples were taken from six profiles of Beadle clay loam (fine, montmorillonitic, mesic, Typic Argiustoll). These samples were analyzed for pH, organic C, texture, CaCO₃, antecedent soil water content, cation-exchange capacity (CEC), and aggregate stability. Isolated test plots were also saturated with an overhead sprinkling infiltrometer. Samples were taken periodically throughout a 4-d period for aggregate-stability determination. A modified wet sieving technique, which included pre-humidifying of the sample to near saturation, was used to determine aggregate stability. A negative linear relationship was found between aggregate stability of prehumidified aggregates and antecedent soil water content. Prediction equations were developed that explain up to 77% of variability for the aggregate stability. Organic C was the most important of the independent variables, followed by antecedent soil water content in the multiple regression analysis. Topsoil removal by desurfacing and erosion reduced aggregate stability. Aggregate stabilities for soils with high organic C and clay content were less affected by antecedent soil water content.
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