The relationship between the soil erodibility factor K (Universal soil loss equation), aggregate stability and micromorphological properties of soils in the Hornos area, S. Spain

Wischmeier's soil erodibility factor K calculated for 10 surface soils in the Hornos area, S. Spain, is compared with 3 aspects of aggregate stability. A significant correlation is found with the percentage of particles < 100 μm after aggregate breakdown, which is used as a measure of the vulnerability of the soil to erosion by overland flow. No significant correlation exists with the number of water drops required to cause breakdown of the aggregates nor with the mean size of the shattered aggregates, both being aspects of the resistance of aggregates to splash erosion. Of the micromorphological and analytical soil properties explaining aggregate stability, only the clay and silt content and the number of closed voids are significantly correlated with the factor K. The aggregate stability of the investigated soils is mainly determined by soil properties inherited from the parent material; the stabilizing effect of pedological features is small.