| Title: | Manure nutrient management effects in the Leon River Watershed |
| Authors: | Rossi, C.G., T.J. Dybala, C. Amonett, J.G. Arnold and T. Marek |
| Year: | 2012 |
| Journal: | Journal of Soil and Water Conservation |
| Volume (Issue): | 67(3) |
| Pages: | 147-157 |
| Article ID: | |
| DOI: | 10.2489/jswc.67.3.147 |
| URL (non-DOI journals): | |
| Model: | SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | BMP and/or cropping system assessment |
| Secondary Application Category: | nutrient cycling/loss and transport |
| Watershed Description: | 9,277 km^2 Leon River, located in central Texas, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | The Leon River Watershed (LRW) in central Texas is a Benchmark and Special
Emphasis watershed within the Conservation Effects Assessment Project located in central
Texas. Model simulations from 1977 through 2006 were used to evaluate six manure nutrient
management scenarios that reflect realistic strategies that could be employed to reduce
nutrient and sediment loadings in the LRW. Due to the presence of several dairies and a relatively
large number of cows, special attention within this watershed is necessary to determine
beneficial adjustments that can be made to protect water quality. The nutrient management
scenarios analyzed reduced total nitrogen (N) and total phosphorus (P) loading in nearly all
of the subbasins. Total N and total P loading was also reduced at the watershed scale; sediment
load reduction was minor due to effective management measures already existing within the
LRW. The percentage change in total N and total P loadings varied from an increase of 3%
to a decrease of 11% and an increase of 5% to a decrease of 12%, respectively. The percentage
change in sediment loadings varied from an increase of 22% to a decrease of 12% per subbasin.
Model simulations conducted over a 30-year period for six manure management scenarios
indicated that both total N and total P can be significantly reduced by employing additional
nutrient strategies. This is the case whether the nutrients are removed from the immediate
vicinity of the dairy or are transported outside of the watershed. |
| Language: | English |
| Keywords: | Conservation Effects Assessment Project (CEAP), hydrologic modeling, Soil Water Assessment Tool (SWAT), subbasin, watershed modeling |