Submitted to: International Soil Conservation Organization Conference Proceedings
Publication Type: Abstract only
Publication Acceptance Date: 5/24/1999
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Previous studies have shown that polyacrylamide (PAM) soil amendments have been effective in reducing runoff and soil erosion by stabilizing soil structure and reducing soil sealing. Recent studies of PAM soil amendments have focused on agricultural lands, which typically have low slopes. It was hypothesized that the beneficial effects of PAM observed in previous studies could also be achieved on steeper slopes, and that grass seedling establishment would be improved due to a more stable soil structure. This study evaluated the effects of anionic PAM soil amendments on runoff, sediment yield, and grass seedling establishment on critically disturbed steep slopes, under both natural and simulated rainfall conditions. Natural rainfall studies were conducted at two sites near Logansport, Indiana in 1997 and 1998. The treatments tested were PAM applied alone, PAM applied with gypsum, and a control. For each treatment, three replicate plots (3m x 9m) were constructed on a 33% slope. All plots were tilled to uniform roughness, fertilized, and grass seeded. PAM was sprayed on the plots at a rate of 80 kg/ha in solution and powdered gypsum was applied at a rate of 5000 kg/ha. Another study was conducted using rainfall simulators to evaluate the effect of the same PAM soil amendment treatments on sediment yield and runoff under severe initial storm conditions on freshly disturbed soil. Both PAM treatments resulted in significantly reduced runoff and sediment yield in comparison with the control. Qualitative measures of seedling establishment demonstrate that both PAM treatments resulted in better grass establishment compared to the control.