The Physical Changes in Soils of the Southern High Plains Due to Cropping and Wind Erosion and the Relation between the Sand + Silt/Clay Ratios in these Soils 1

on the effect of water erosion on the physical properties of erosive and non-erosive soils in the humid regions, however, very little information is available on the physical properties of soils affected by wind erosion in the southern high plains of the United States. Some studies on soil drifting were made in Canada by Moss (x ~), who found that the drift from the mediumand coarse-textured soils contained more sand and less silt and clay than the undrifted soil, while the mechanical composition of fine-textured soils and the drift was almost identical. The factors affecting water erosion were studied by .Lutz (7) and he found that Davidson clay, a comparatively non-erosive soil, contained a higher percentage of clay than the Iredell sandy clay, an erosive type of soil. He states that the erosiveness of the Iredell was due to the ease with which it dispersed and its impermeability to water, while the non-erosive nature of the davidson was due to the high state of flocculation of its finer mechanical separates into porous, stable granules which resist dispersion and permit a rapid percolation of water through the soil profile. Middleton (8) states that, "the properties having the greatest influence on soil erosion are indicated by dispersion ratio, ratio of colloids to moisture equivalent, erosion ratio and silica-sesquixide ratio." sand + silt Bouyoucos (i) made a comparison between the clay ratio