View article

Ten soil sites in western Kansas sampled in 1948 were resampled in 1984 to compare the particle size distribution (texture) and organic matter content in the top 10 cm. Except at one site, the sand fraction increased; this increase ranged from 0.9 to 23.3 percentage points. The greatest changes occurred in the moderately coarse and coarse textured (sandy) soils. Overall changes in particle distribution were + 6.5, −7.2, and +0.7 percentage points for sand, silt, and clay, respectively, indicating that silt was removed through sorting by wind. Organic matter declined at 8 of the 10 sites, averaging about 19% overall or about 0.01 percentage points per year. Erosion or other factors are causing a slow decline in silt content and organic matter in these soils, with potentially detrimental effects on soil structure, nutrient availability, and water-holding capacity.