Co-Authors:
Flanagan, D.C., ASAE, USDA-AgricuItural Research Service, USDA-Agricultural Research Service NSERL, 1196 Building SOIL, West Lafayette, IN 47907-1196, United States
Norton, L.D., USDA-Agricultural Research Service, Purdue University, West Lafayette, IN, United States
Shainberg, I., Volcani Center, Ben Dagan, Israel
Abstract:
This research examined the effect of rainfall and runoff water composition, as well as the effect of different soil surface amendments on infiltration, runoff, and soil loss from a silt loam soil which was highly susceptible to aggregate breakdown and sealing. This article describes the soil erosion results, while infiltration and runoff findings are presented in a companion article. The purposes of this study were to test if soil erosion would be reduced by the presence of electrolytes in the erosive water, if use of an anionic polyacrylamide (PAM) as a surface spray or in rain water would reduce soil loss, and what the combined effects of high electrolyte concentrations and PAM would be. The impacts of a soil surface application of 20 kg/ha of an anionic PAM as well as 5 t/ha of a gypsiferous power-plant byproduct on soil loss were determined. Water type applied as rainfall or inflow was deionized, tap, or tap plus 10 ppm of PAM. The soil surface applications of the PAM were effective in controlling rill erosion, even at very high water inflow levels. Rill plot sediment discharge rates from deionized rainfall water applications to an initially dry soil surface were significantly greater than those resulting from rainfall having greater electrolyte concentrations. However, when inflow water was added to actively eroding rills, electrolyte concentration had no significant effect on sediment concentration or sediment discharge rate. The presence of PAM in rain water and inflow water acted to enhance soil loss when sufficient runoff was present to transport sediment from the rills.