The Upper North Bosque River (UNBR) watershed is under a Total Maximum
Daily Load (TMDL) mandate to reduce Phosphorus (P) due to excess nutrients in the
watershed. To address these problems, Texas A&M University researchers have
developed a turfgrass sod Best Management Practice (BMP) to remove excess nutrients
from impaired watersheds. Turfgrass harvest of manure fertilized sod removes a thin
layer of topsoil with most of the manure applied P. Plot and field scale research has
demonstrated the effectiveness of turfgrass to remove manure phosphorus (P). In order
to assess the impact of the turfgrass BMP on a watershed scale, the Soil and Water
Assessment Tool (SWAT) was used to predict water quality in the UNBR watershed.
The SWAT model was modified to incorporate turfgrass harvest routines to predict
manure and soil P export through turfgrass sod and soil during harvest. SWAT
simulations of the BMP predicted stream load reductions of 20 to 36% for P loads in the
UNBR depending on the implementation scenario, an average reduction of 31% for total
N and 16.7% for sediment for all the scenarios, at the watershed outlet. The SWAT
model also predicted up to 176 kg/ha P removed per sod harvest when fertilized with
100 kg manure P/ha, and 258 kg/ha of P removed per sod harvest when the manure P
application rate was 200 kg/ha. In addition, depending on the implementation scenario,
the turfgrass BMP could export between 262 and 784 metric tons of P out of the UNBR
watershed every year.
Manure fertilized turfgrass has the advantage of slow releasing nutrients from the
composted dairy manure, so it would not require any additional P for life. This means
reduced urban non-point source pollution and lower maintenance cost compared to
regular sod. These modeling simulations complement the wealth of research that shows
the effectiveness of the turfgrass BMP.
| Identifer | oai:union.ndltd.org:tamu.edu/oai:repository.tamu.edu:1969.1/1428 |
| Date | 17 February 2005 |
| Creators | Stewart, George Russell |
| Contributors | Munster, Clyde L. |
| Publisher | Texas A&M University |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | Book, Thesis, Electronic Thesis, text |
| Format | 3217687 bytes, electronic, application/pdf, born digital |
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