Mississippi State University
Varco, Jac J.
Stewart, Barry R.
Locke, Martin A.
Lemus, Rocky W.
Date of Degree
Dissertation - Open Access
Doctor of Philosophy (Ph.D)
College of Agriculture and Life Sciences
Department of Plant and Soil Sciences
Runoff during the revegetation of roadsides can transport sediment and nutrients offsite, leading to surface water quality reductions. Two field experiments were conducted near Starkville, MS in 2011 and 2012 to evaluate the influence of N and P sources and rates, fertilization timing, and mulch type on vegetative establishment and nutrient and sediment runoff losses. Stainless steel runoff frames (0.75 x 2.0 m) were installed on 10% and 15% slopes for Experiment I and Experiment II, respectively. A bahiagrass (Paspalum notatum Flugge), tall fescue [Schedonorus arundinaceus (Schreb.) Dumort., nom. cons.], sericea lespedeza [Lespedeza cuneata (Dum. Cours.) G. Don], and common bermudagrass [Cynodon dactylon (L.) Pers.] mixture was seeded within each frame during Experiment I. Crimson clover (Trifolium incarnatum L.) was added for Experiment II. Experiment I treatments consisted of 73.5 or 147 kg N ha-1 as 13-13-13, poultry litter, ammonium nitrate, stabilized urea, polymer coated urea, or diammonium phosphate. Experiment II treatments consisted of wheat straw and six hydromulches; paper fiber, wood fiber, wood/paper fiber blend, flexible growth medium (FGM), extended term-FGM (ET-FGM), bonded fiber matrix (BFM). Runoff from natural and simulated rainfall was analyzed for PO43--P, total P (TP), NH4+-N, NO3- -N, total N (TN), and total solids (TS). Experiment I results suggest the greatest N and P runoff losses occurred during the first runoff event following fertilization. Splitting 147 kg N ha-1 into two equal applications increased nutrient losses compared to one application. Application of organic plus inorganic P increased PO43--P in runoff compared to inorganic P alone. Experiment II results indicate straw was the most effective mulch for increasing vegetative establishment and limiting solids and nutrients in runoff. However, lack of fertilizer prill dissolution may have influenced nutrient runoff losses during dry conditions. The FGM, ET-FGM, and BFM mulch treatments were more effective than the paper, wood, and paper/wood fiber treatments in reducing solids and nutrients in runoff. It was apparent during both experiments that timing, intensity, and duration of rainfall events following fertilization have an influence on runoff losses. However, further research is needed to quantify the influence of those rainfall parameters.
Briscoe, Kyle R., "Evaluation of Sediment and Nutrient Loss during the Revegetation of Mississippi Roadsides" (2014). Theses and Dissertations. 2059.