Forage species and canopy cover effects on runoff from small plots

M.L. Self-Davis; P.A. Moore; T.C. Daniel; D.J. Nichols; T.J. Sauer; C.P. West; G.E. Aiken; D.R. Edwards

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. This study sought to evaluate the effect of five forage species at varying canopy heights (one day vs. six weeks growth post-harvest) on surface runoff and infiltration on 6.1 m × 6.1 m (20 × 20 ft) plots fertilized with poultry litter. The five forage species were: Alamo switchgrass (Panicum virgatum L), Caucasian bluestem (Bothriochloa caucasia (Trin.) C.E. Hubbard), 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 (4.0 ton/acre). Rainfall simulations (5.0 cm hr⁻¹) (2.0 in hr⁻¹) 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, by an average of 18% for all species except bermudagrass. Comparisons of runoff volumes between the different species showed that tall fescue had significantly lesser (30 mm) runoff for three of the four runoff events. There were no differences in runoff between the other four species, for any runoff event. Infiltration was on average 19% 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 average profile volumetric water content from 3 to 5 m³ m⁻³ (106 to 177 ft³ ft⁻³) lower at the 20 and 35 cm (7.9 and 13.8 in) depths. 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.

Footnotes

M. LeAnn Self-Davis is an assistant professor at the Department of Chemistry and Engineering Sciences, Freed-Hardeman University in Henderson, Tennessee. Philip A. Moore Jr. is a research scientist at the U.S. Department of Agriculture — Agricultural Research Service at the University of Arkansas, in Fayetteville, Arkansas. Thomas C. Daniel and Charles P. West are professors at the Agronomy Department, University of Arkansas, in Fayetteville, Arkansas. Doyle J. Nichols is a research technician and Thomas J. Sauer is a research scientist, both at the U.S. Deapartment of Agriculture — Agricultural Research Service at the National Soil Tilth Lab in-Ames, Iowa. Glenn E. Aiken is at the U.S. Deapartment of Agriculture — Agricultural Research Service at the University of kentucky, in Lexington, Kentucky. Dewayne R. Edwards is a professor at the Department of Agricultural Engineering, University of Kentucky, in Lexington, kentucky.
Copyright 2003 by the Soil and Water Conservation Society

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