|Nichols, Doyle - Jeff|
|Sauer, Thomas - Tom|
Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/1/2003
Publication Date: 11/1/2003
Citation: Self-Davis, M.L., Moore Jr, P.A., Daniel, T.C., Nichols, D.J., Sauer, T.J., West, C.P., Aiken, G.E., Edwards, D.R. 2003. Forage species and canopy cover effects on runoff from small plots. Journal of Soil and Water Conservation. 58:349-359. Interpretive Summary: The type of forage grown in pastures has a big impact on the amount of runoff. The objective of this study was to evaluate the effect of five forage types and canopy height on surface runoff and infiltration from small plots. The five forage species were switchgrass, bluestem, bermudagrass, tall fescue and Eastern gamagrass. Rainfall simulations were used to provide runoff events in spring, summer and fall. Runoff volumes were reduced when canopy heights were greater, except for bermudagrass. Tall fescue had the significantly lower runoff volumes in 3 of 4 runoff events. Infiltration was also greater with tall fescue. These results indicate that tall fescue is more effective at reducing runoff and increasing infiltration than other forages, and should thereby reduce edge of field nutrient losses.
Technical Abstract: Studies have shown that the surface hydrology of a pasture system is influenced by its vegetative characteristics. As research continues on ways to prevent erosion and excessive nutrient loss from agricultural land, the effect that different forage species have on surface runoff requires further investigation. It was the objective of this study to evaluate the effect of five forage species at varying canopy heights (one day v six weeks growth post harvest) on surface runoff and infiltration on plots fertilized with poultry litter. The five forage species were: Alamo switchgrass ( Panicum virgatum L.), Caucasian bluestem (Bothriochloa caucasia (Trin.) C.E. Hubb.), Greenfield bermudagrass (Cynodon dactylon (L.) Pers.), Pete Eastern gamagrass (Tripsacum dactyloides (L.) L.) , and Kentucky-31 Tall fescue (Festuca arundinacea Schreb.). Poultry litter was surface applied annually at 8.97 Mg ha-1. Rainfall simulations were used to produce runoff events during spring, summer, and fall to examine seasonal variations. Although there were no statistical differences in runoff volumes between cut canopy and full canopy covers within a single species, runoff volumes were reduced by full canopies, for all seasons, for all species except bermudagrass. Comparisons of runoff volumes between the different species showed that tall fescue had significantly lower runoff volumes for three of the four runoff events. There were no differences in runoff volumes between the other four species, for any runoff event. Infiltration was greater in tall fescue plots for all runoff events, compared to the other four species. Neutron probe data supported these results, with tall fescue plots consistently having the lowest volumetric water content to a depth of 35 cm. Results of this study show that tall fescue, when directly compared to the other forages in this study, is more effective at reducing runoff volumes and increasing infiltration, thereby reducing edge of field loss in forage systems.