Temporal Changes in Soil Erodibility

Soil erodibility has been considered to depend on soil permanent properties (e.g., texture and organic matter content). In this presentation the dependence of interrill and rill erodibility on prewetting rate (PWR) and aging, respectively, is discussed. Slow wetting of soils reduces seal formation, runoff, and interrill erosion. Similarly, aging reduces rill erosion. The effects of wetting rate and aging on runoff and erosion depended on soil texture. Soils with >30% clay were very susceptible to PWR; erodibility in these soils increased with an increase in wetting rate and decreased with prolonged aging. Slow wetting reduced erosion in vertisols to <10% of that in fast wetting. Conversely, sandy loams were less affected by wetting rate and aging. The inconsistent and often conflicting results reported in the literature regarding the erodibility of soils could be ascribed to temporal changes in soil erodibility.