Evaluation of Species for Rapid Establishment On Mississippi Roadsides.

Non-point source pollution (NPS) caused by erosion from road construction poses hazardous environmental effects leading to percolation and infiltration of nutrients into groundwater.  In addition, the annual roadside maintenance budget for mowing exceeds millions of dollars.  To combat NPS, the Environmental Protection Agency (EPA) has mandated that MDOT achieve 70% cover in 30 days.  The objectives of this study were to evaluate rapidly establishing species to prevent erosion, combat NPS, and reduce mowing cost.  Factors evaluated were rate of establishment, plant cover, and mowing requirement.  Two years of summer and fall plantings were conducted for the experiment.  The 2012 summer planting was located in the median of a newly constructed 4 lane highway in Columbus, MS along MS Hwy 45.  Both 2011 and 2012 fall plantings were located at the R.R. Foil Plant Science Research Facility at Mississippi State University.   Summer plantings received the standard MDOT fertilizer rate of 1,136 kg ha^-1 of 13-13-13 while fall plantings received 48.8 kg ha^-1 13-13-13.  Species evaluated were: Oilseed radish (Raphanus sativus), bermudagrass (Cynodon dactylon), bahiagrass (Paspalum notatum), centipedegrass (Eremochloa ophiuroides), zoysiagrass (Zoysia japonica), red clover (Trifolium pratense ), white clover (Trifolium repens), Texas bluegrass (Poa arachnifera), tall fescue (Festuca arundinacea), creeping red fescue (Festuca rubra), and annual ryegrass (Lolium multiflorum) and Pennington’s Slopemaster™ product.  Plant cover and rate of establishment were evaluated visually and using electronic images using Sigmascan Pro 5.  Results showed more favorable conditions for fall plantings than summer plantings and mulch aided in establishment.  Oilseed radish established quicker and provided the most cover in all plantings.