| Title: | Seasonal manure application timing and storage effects on field and watershed level phosphorus losses |
| Authors: | Liu, J., T.L. Veith, A.S. Collick, P.J.A. Kleinman, D.B. Beegle and R.B. Bryant |
| Year: | 2017 |
| Journal: | Journal of Environmental Quality |
| Volume (Issue): | 46(6) |
| Pages: | 1403-1412 |
| Article ID: | |
| DOI: | 10.2134/jeq2017.04.0150 |
| URL (non-DOI journals): | |
| Model: | Topo-SWAT |
| Broad Application Category: | hydrologic and pollutant |
| Primary Application Category: | phosphorus cycling/loss and transport |
| Secondary Application Category: | BMP and/or cropping system assessment |
| Watershed Description: | 7.3 km^2 WE38 drainage area, located within the overall Chesapeake Bay Basin in south central Pennsylvania, U.S. |
| Calibration Summary: | |
| Validation Summary: | |
| General Comments: | |
| Abstract: | Timing of manure application to agricultural soils remains
a contentious topic in nutrient management planning,
particularly with regard to impacts on nutrient loss in runoff and
downstream water quality. We evaluated the effects of seasonal
manure application and associated manure storage capacity on
phosphorus (P) losses at both field and watershed scales over an
11-yr period, using long-term observed data and an upgraded,
variable-source water quality model called Topo-SWAT. At the
field level, despite variation in location and crop management,
manure applications throughout fall and winter increased
annual total P losses by 12 to 16% and dissolved P by 19 to 40%
as compared with spring. Among all field-level scenarios, total P
loss was substantially reduced through better site targeting (by
48–64%), improving winter soil cover (by 25–46%), and reducing
manure application rates (by 1–23%). At the watershed level, a
scenario simulating 12 mo of manure storage (all watershed
manure applied in spring) reduced dissolved P loss by 5% and
total P loss by 2% but resulted in greater P concentrations peaks
compared with scenarios simulating 6 mo (fall-spring application)
or 3 mo storage (four-season application). Watershed-level
impacts are complicated by aggregate effects, both spatial
and temporal, of manure storage capacity on variables such as
manure application rate and timing, and complexities of field and
management. This comparison of the consequences of different
manure storage capacities demonstrated a tradeoff between
reducing annual P loss through a few high-concentration runoff
events and increasing the frequency of low peaks but also
increasing the annual loss. |
| Language: | English |
| Keywords: | |