| Abstract: | The effect of runoff generation on the erosion of gypsiferous soils under different experimental conditions was investigated by applying simulated rainfalls of 48 and 58 mm h−1 to experimental plots exhibiting representative characteristics of these soils. The 45 experiments indicate differing erosive behaviour as test conditions varied. Suspended gypsum yields ranged from 0-3.9 gm−2 h−1 the higher values occurring with the steeper slopes and dry soil conditions. The differences among the soils tested were mainly due to variations in underlying rock outcrop, whilst within each soil type, slope was the most important variable. Transport of suspended gypsum by runoff is inversely related to rock outcrop, and positively related to slope. The highest erosion rates are registered in Gypsic Calcisols, followed by Gypsic Calcisols (lithic phase), while production of suspended gypsum is not verified for Dystric Leptosols. By transporting gypsum particles down-slope, runoff is probably responsible for the dynamic evolution of gypsiferous hillslopes as well as the genetic evolution of the studied soils. |
