Factors Affecting the Stability of Soil Crusts in Subsequent Storms

Abstract

AbstractConflicting results exist concerning the effect of drying on the properties of soil crusts. In this study the hypothesis that the stability of crust to drying depends on the processes that predominate during its formation was tested by studying the effect of application of distilled (DW) and saline water (SW) (EC = 5 dS m−1) on the infiltration rates (IR) of a crusted soil surface. A Typic Rhodoxeralf and a Calcic Haploxeralf saturated with low (< 3.5) and high (17 < ESP < 20) exchangeable sodium percentages (ESP) were exposed to simulated rain of low and high energy levels. The soils were oven‐dried at 35°C for 24 and 72 h between consecutive storms. The stability of the crust was found to depend on the mechanisms of its formation. The crusts of soils with low ESP exposed to DW and SW rain and the crust of a soil with high ESP exposed to SW rain were found to be unstable and to be affected strongly by (i) the salinity of the rain water in subsequent storms, (ii) the impact energy of the raindrops, and (iii) the length of the drying period between consecutive storms. Conversely, a crust in which chemical dispersion supplemented physical dispersion (a soil with high ESP exposed to DW rain) was found to be stable and to be less affected by the water salinity of the subsequent storm, by its impact energy, or by the extent of drying between storms.