Date of Award
Master of Science (MS)
Division of Agriculture (SAFES)
Charles V. Privette III
Calvin B. Sawyer
Dara M. Park
Establishing permanent perennial vegetation that is uniform and covers at least seventy percent of disturbed areas is a requirement to close-out a construction project in South Carolina. The South Carolina Department of Health and Environmental Control (SCDHEC) and the South Carolina Department of Transportation (SCDOT) have well established procedures and protocols for contractors when establishing vegetation. However, difficulties are often faced by contractors to attain these coverage thresholds, resulting in negative consequences not only to the environment but also additional monetary costs.
A two-year study was conducted at Clemson University’s Agricultural Sciences Erosion Testing Facility to evaluate these difficulties. The study tested two different soil amendments incorporated into poor Ultisols (subsoil); topsoil and a biological growth stimulant (BGS), coupled with the use of supplemental watering on establishing vegetation. Poor Ultisols (subsoil) are commonly planted on for final stabilization in the Piedmont ecoregion of South Carolina, and often result in poor vegetative coverage. Vegetation types chosen for the study were Kentucky #31 Fescue (Festuca arundinacea) and Common Bermudagrass (Cynodon dactylon). Plantings occurred during the spring and summers of 2019 and 2020. In addition, a rainfall simulator was used to simulate a 25-year storm event for the region (101.6 mm/hr) on two different soil moisture conditions: “dry” conditions (ARC I) and “saturated” conditions (ARC III). Runoff was collected and analyzed for turbidity and total suspended solids (TSS) in effort to determine how percent vegetative coverage effects runoff water quality. A Standard Least Squares Regression model producing an ANOVA table, was used to analyze the final percent vegetative coverage and water quality (turbidity and TSS) data.
For the 2019 experiments, topsoil amended plots receiving supplemental water (AMD-SW) produced the highest final coverage (66.37-88.77% for fescue and 75.88-89.55% for bermudagrass). Both 2019 tests revealed the interaction effects between the two treatments made a significant difference in the final percent coverage (p-values < 0.05). In the 2020 experiments, the BGS plots receiving supplemental water (BGS, AMND-SW) resulted in the greatest coverage for fescue (76.84%). No treatment significantly influenced cover in the 2020 fescue test (p-values > 0.05). The 2020 bermudagrass test resulted in the BGS non-supplemental watered (BGS, AMND-NSW) plots attained the highest coverage (84.93-90.47%), and a statistical relationship was determined for the non-supplemental water (NSW) treatment (p-value < 0.05). The water quality data revealed no statistical difference in percent vegetative coverage effect on TSS, but a negative relationship with percent vegetative coverage and turbidity (p-value < 0.05).
Barnette, Ethan Richard, "Analysis of Soil Amendments and Supplemental Watering For Establishing Fescue and Bermudagrass on Poor Soils in the Piedmont Region of South Carolina" (2020). All Theses. 3424.