DRY AGGREGATE SIZE DISTRIBUTION OF SANDY SOILS AS INFLUENCED BY TILLAGE AND PRECIPITATION

Surface soil dry aggregate size distribution (ASD) has a significant effect on the amount and intensity of wind-induced soil erosion. The ASD of cropland caries through time primaily due to the effects of management and climatic factors. A method of predicting ASD is needed to make accurate estimates of wind erosion. The effects of tillage on ASD are described and models proposed to estimate changes in ASD after precipitation has further modified a sandy soil surface. The ASD and bulk density of the near-surface soil were measured on four west Texas sandy soils immediately after tillage and after up to 130 mm subsequent rainfall. Tillage methods included moldboard plow, lister, chisel, and tandem disk. -from Authors