Influence of a riparian buffer on a deep loess soil

Riparian buffers possess the capacity to serve as an effective tool against non-point source pollution, while, providing numerous benefits in a wide range of environmental settings. The use of riparian buffers as an effective conservation practice has been studied extensively in central Iowa but few if any research exists on the effect of a riparian buffer on the erosion prone loess hills of southwest Iowa. Rainfall simulations were performed in May of 2004 and 2005 within 1.22 m x 2.44 m plots on a Kennebec silt loam and were replicated five times per vegetation. The riparian buffer was composed three vegetation zones that included trees (cottonwoods, Populus deltoids Bartr.; black walnut, Juglans nigra L.), cool season grass (smooth bromegrass, Bromus inermis Leyss), and warm season grass (switchgrass, Panicum virgatum L.). Comparisons were made between the row-crop and the individual vegetation zones of the riparian buffer. Significantly higher infiltration rates were observed in the vegetation zones of the riparian buffer when compared to the row crop (p \u3c0.05). Noticeably higher antecedent surface soil moisture was found in the riparian buffer vegetations. The cottonwood trees of the riparian buffer proved to display higher soil moisture when compared to the other vegetations of the riparian buffer and the row crop. A significant amount of sediment loss occurred in the row crop during rainfall simulations. The amount of sediment loss during rainfall simulations performed in the vegetation zones of the riparian buffer was nearly 75 % less than that of the row crop. Lower soil bulk densities were also noticed when compared to the row crop rotation system. The results indicate the positive influence a riparian buffer has on soil physical and hydraulic properties on loess soil