| dc.description.abstract | Excessive phosphorus (P) in runoff contributes to eutrophication of fresh water
bodies. Studies have shown that manure and effluent applied from animal feeding
operations to waste application fields (WAFs) have contributed to excess P in segments
of the North Bosque River in east central Texas. There is a growing need for
environmentally sound, economically viable, and easy to establish best management
practices to control such pollution. Vegetative buffer strips offer a potential solution for
reducing runoff P from WAFs by extracting it from soil and by reducing sediment P
delivery (due to reduced runoff and soil erosion) to streams. In a field study, ten plots
(5m x 5m) were assigned to five replicated treatments, namely control (bare, without
having any plant cover), cool season grass, warm season forb, warm season grass, and
warm season legume to assess their efficacy of runoff sediment control and P
sequestration potential from soil. These plots were established on a coastal Bermuda
grass WAF that received dairy lagoon effluent.
A runoff collection system, a 1m x 1m sub-plot with a runoff conveyance and
collection apparatus, was installed on the upstream and downstream margins of each plot. Natural rainfall runoff samples were collected and analyzed subsequently for total
P, soluble P, and total suspended solids in the laboratory. Additionally, the total mass of
runoff collected from each sub-plot was calculated. Results suggested that the warm
season forb and warm season grass were the most effective vegetative covers for the
reduction of runoff P, followed by coastal Bermuda and cool season grass, respectively.
The lesser amount of runoff total P in these two treatments was due to lesser runoff mass
and lesser sediments in the runoff due to initial interception of rain and less raindrop
impact on soil because of denser vegetative cover in both treatments compared to all
other treatments. | en |
