Click on “Download PDF” for the PDF version or on the title for the HTML version.

If you are not an ASABE member or if your employer has not arranged for access to the full-text, Click here for options.

Excess rainfall contributes to significant surface runoff, soil erosion, and nutrient loss to surface waterways typical of the Lower Mississippi River Valley. The USDA, ARS, Soil and Water Research Unit in Baton Rouge, LA, is currently evaluating the impacts of tillage (deep chiseling) and residue management, shallow and controlled subsurface drainage, and soil stabilization [polyacrylamide (PAM)] on infiltration and surface runoff of rainfall, soil erosion, and nutrient loss. At our Ben Hur field site [Commerce silt loam soil (Aeric Fluvaquents)], we are evaluating the impacts of deep tillage on 0.2 ha plots to determine the impacts on infiltration, runoff, soil erosion, and nutrient loss. The comparison of data from this site (1995-96, minimum tillage) and previous research from a nearby site (same soil, regularly deep tilled) suggests that deep tillage increased infiltration, and decreased runoff and nutrient loss. However, these tillage impacts have not been directly evaluated. Also at the Ben Hur site, we are comparing the effects of shallow subsurface drainage (0.6 m deep drain line) to controlled subsurface drainage at 0.6 m deep using existing drain lines installed at a 1.2 m depth. This evaluation of subsurface drainage systems supports efforts to reduce nutrient loss from drained agricultural soils, particularly of the Midwest U.S. Preliminary data from our St. Gabriel field site (same soil) indicate that leaving sugarcane residue in the furrow rather than burning the residue, decreased drainage ditch erosion by 64 %, and by 87% when coupled with PAM application to the ditches. This study is currently being repeated, and an additional large-scale soil column study is underway to screen potential PAM application techniques and possible interactions agrochemical application and efficacy. First-year data from these studies will be presented as available.