|Southwick Jr, Lloyd|
Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 1, 2004
Publication Date: March 1, 2005
Citation: Kornecki, T.S., Grigg, B.C., Fouss, J.L., Southwick Jr, L.M. 2005. Polyacrylamide (PAM) application effectiveness in reducing soil erosion from sugarcane fields in southern Louisiana. Applied Engineering in Agriculture. 21(2):189-196. Interpretive Summary: Each year in early spring, quarter drains-small surface ditches perpendicular to sugarcane rows are installed to provide drainage of runoff water from furrows to main surface ditches. High rainfall energy from intense storm events causes soil erosion from the semicircular shape of quarter drains. The sediment diminishes flow capacity of the quarter-drains especially at junctions with main ditches within the field. This is important in the Southern Louisiana where flat agricultural land with slopes up to 0.5% provides only a limited outflow of runoff waters from sugarcane fields. Thus, maintaining good functionality of quarter drains it is essential for removing runoff water for optimum sugarcane growth. To address the soil erosion from quarter drains a field experiment was conducted at USDA ARS research site in St. Gabriel, LA to study the impacts of anionic polyacrylamide (PAM) on soil erosion. During six (6) storm events in spring 2002, PAM significantly reduced erosion depth in quarter drains about 78%, compared with no-PAM application. For a soil bulk density of 1.5 Tonnes/m3, the average soil loss reduction from these storms using PAM was 13 kg per 34 m (typical length) of quarter drain. Based on these results, PAM was effective in reducing soil erosion with a single application during the 4 month study period.
Technical Abstract: A field experiment was conducted in the spring of 2002 to determine the effectiveness of high molecular weight anionic polyacrylamide (PAM) in stabilizing quarter drains(reducing soil erosion) on fields planted to sugarcane. Quarter drains are small surface ditches perpendicular to sugarcane furrows on sugarcane land. During the experiment, six (6) storm events occurred with total cumulative rainfall of 369 mm. When applied directly to the quarter drains at a rate of 18 kg/ha, PAM reduced soil loss by 15 kg per 23 m for the primary, and by 10 kg on 11 m of the secondary quarter drain. The average reduction was 13 kg per 34 m (78% reduction)for both quarter drains with PAM application. For a soil bulk density of 1.5 Tonnes/m3, expressing results per unit area, the soil loss was 0.07 kg/m2 and 1.5 kg/m2 for PAM and no PAM treatments, respectively. The most erosion occurred at transition points between quarter drains and connecting ditches. Data and visual observations showed that PAM preserved the original shape of the semicircular quarter drains through six consecutive storms events, whereas for plots where PAM was not applied, a gradual deterioration of the side walls of the quarter drain was visible, including the transitions points, where erosion depth up to 30 mm was recorded.