Soil berms as an alternative to steel plate borders for runoff plots

Steel plates are often used to border runoff-erosion plots, but they are difficult to install and are expensive. This study assessed the effectiveness of using polyacrylamide (PAM; 2-propenamide, homopolymer) treated soil with and without geotextile fabric (GF) for soil berm plot borders in laboratory and field conditions. Hemispherically shaped soil berms of 250 mm wide by 150 mm high were constructed in erosion boxes. Erosion and runoff from untreated berms, berms treated with 9 kg ha-1 of PAM, and berms treated with 9 kg ha-1 of PAM and covered with GF (PAM-GF) were measured under simulated rainfall. A dry simulation run was conducted for 1 h followed by a wet simulation run after 24 h under field conditions. The PAM-GF reduced soil erosion from berms by 99% when compared with the untreated soil berm (control). Use of PAM alone reduced erosion from berms by approximately equal to 84%; however, erosion with PAM increased rapidly with time. Effectiveness of PAM alone decreased for reducing soil loss from 94% in the first 10 min of the 1-h dry run to 27% by the end of the 1-h wet run in field conditions. Although some runoff occurred from berms into the plots, this was insignificant for plot-to-berm ratios 10:1(P < 0.01). Results show that soil berms treated with PAM and GF reduced erosion to nondetectable levels. The cost for soil berm construction is about 10% of that for steel plate plot borders. The PAM-GF treated soil berms can be an economical alternative to conventional steel plate plot borders especially for short-term runoff studies.