Similarities and dissimilarities between the dynamics of sand and dust during wind erosion of loamy sandy soil

Aeolian dynamics were measured during a wind erosion event on an agricultural field in Northern Germany. Because the topsoil was loamy sand, particle flow behaved as a sand–dust mixture and not as pure sand (>63 m) or pure dust (<63 m). Although generally similar, the erosion, transportation and deposition patterns were not identical for the two particle fractions. The difference was most pronounced for accumulation (defined as deposition minus erosion). For dust, accumulation was negative all over the field because grains were removed in dust clouds. For sand, spots of negative accumulation (erosion) alternated with spots of positive accumulation (accretion) and the net result for the field as a whole was close to zero. The study shows that accumulation maps cannot be used to reconstruct the areas of high aeolian activity. It also demonstrates that during wind erosion, the wind behaves as a selective medium. In topsoil with a median grain diameter between 40 and 160 m, fine particles are more easily eroded than coarse. In topsoil with a median grain diameter