A study was conducted to evaluate the ability of a multispecies riparian buffer (MRB) to remove sediment, nitrogen, and phosphorus from cropland runoff. Simulated rainfall was applied to 4.1‐ by 22.1‐m bare cropland source areas paired with either no buffer, a 7.1‐m‐wide switchgrass (Panicum virgatum L. cv. Cave‐n‐Rock) buffer, or a 16.3‐m‐wide switchgrass‐woody plant buffer. Each treatment plot combination had three replicates. The switchgrass buffer trapped 70% of the incoming sediment, while the switchgrass‐woody buffer trapped more than 92%. In general, these buffers retained 93% of sand and silt particles and 52% of clay particles. During a 2‐h rainfall simulation at 25 mm h−1, the switchgrass buffer removed 64, 61, 72, and 44% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass‐woody buffer removed 80, 92, 93, and 85% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. During a 1‐h rainfall simulation at 69 mm h−1, the switchgrass buffer removed 50, 41, 46, and 28% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass‐woody plant buffer removed 73, 68, 81, and 35% of the incoming total N, NO3−N, total P, and PO4‐P, respectively. The switchgrass buffer was effective in trapping coarse sediment and sediment‐bound nutrients. But the additional buffer width with high infiltration capacity provided by the deep‐rooted woody plant zone was effective in trapping the clay and soluble nutrients.

Lee, Kye-Han, "Effectiveness of a multi-species riparian buffer system for sediment and nutrient removal " (1999). Retrospective Theses and Dissertations. 12148. https://lib.dr.iastate.edu/rtd/12148 INFORMATION TO USERSThis manuscript has been reproduced from the microfilm master. UMI films the text directly firom the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter face, while others may be from any type of computer printer.The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction.In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion.Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, beginning at the upper left-hand comer and continuing from left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book.