Splash Detachment Under Plant Covers: Results and Implications of a Field Study

Abstract

ABSTRACT FIELD measurements of the detachment of soil par-ticles by raindrop impact were made under cereals on sandy loam, clay and chalk soils and for bare ground on a sandy soil. Although the results are broadly as ex-pected, the data obtained under the cereals indicate that our understanding of the splash erosion process may need to be reappraised. The soils increase in detachabili-ty in the order of clay, chalk and sandy loam/sand. The crop cover was found to reduce splash detachment. A negative relationship was obtained between the rates of splash detachment at the reduced levels prevailing beneath the crop and the kinetic energy of the rainfall received at the canopy. Such a relationship has not been previously reported explicitly in the literature and an ex-planation of it must be sought through research on the way in which a plant cover modifies the volume, drop-size distribution and energy of the rainfall reaching the ground surface. Splash detachment is shown not to be a simple response to raindrop impact as is frequently assumed in laboratory simulations of the process. The in-teractive effects of plant cover, frost action, surface crusting and rainfall intensity must be considered.