TY - JOUR

T1 - Characterising phosphorus loss in surface and subsurface hydrological pathways

AU - Heathwaite, A. L.

AU - Dils, R. M.

N1 - 5 May 2000 Characterising phosphorus loss in surface and subsurface hydrological pathways 83 cites: http://scholar.google.com/scholar?num=100&hl=en&lr=&cites=11117765911240498587

PY - 2000/5/5

Y1 - 2000/5/5

N2 - The magnitude and composition of the phosphorus (P) load transported in surface and subsurface hydrological pathways from a grassland catchment depends on the discharge capacity of the flow route and the frequency with which the pathway operates. Surface runoff is an important pathway for P loss, but this pathway is spatially limited and temporarily confined to high magnitude, high intensity rainfall events. High P concentrations (mean: 1.1 mg TP l−1) were recorded, with most P transported in the dissolved fraction. Preferential flow pathways, particularly soil macropores and field drains, are important contributors to the overall P load; most P is transported in the particulate fraction and associated with organic or colloidal P forms. High P concentrations (mean: 1.2 mg TP l−1) were recorded in macropore flow in the upper 0–15 cm of a grassland soil, and generally declined with increasing soil depth. On average, P concentrations in drainflow were over six times greater in stormflow compared to baseflow. Stormflow P losses in drainflow were predominantly in the particulate fraction; significant correlation (P<0.01) was recorded with suspended sediment concentrations in drainflow. Phosphorus concentrations in groundwater were low (<0.2 mg TP l−1 at 150 cm), although this pathway may contribute to stream flow for the majority of the year.

AB - The magnitude and composition of the phosphorus (P) load transported in surface and subsurface hydrological pathways from a grassland catchment depends on the discharge capacity of the flow route and the frequency with which the pathway operates. Surface runoff is an important pathway for P loss, but this pathway is spatially limited and temporarily confined to high magnitude, high intensity rainfall events. High P concentrations (mean: 1.1 mg TP l−1) were recorded, with most P transported in the dissolved fraction. Preferential flow pathways, particularly soil macropores and field drains, are important contributors to the overall P load; most P is transported in the particulate fraction and associated with organic or colloidal P forms. High P concentrations (mean: 1.2 mg TP l−1) were recorded in macropore flow in the upper 0–15 cm of a grassland soil, and generally declined with increasing soil depth. On average, P concentrations in drainflow were over six times greater in stormflow compared to baseflow. Stormflow P losses in drainflow were predominantly in the particulate fraction; significant correlation (P<0.01) was recorded with suspended sediment concentrations in drainflow. Phosphorus concentrations in groundwater were low (<0.2 mg TP l−1 at 150 cm), although this pathway may contribute to stream flow for the majority of the year.

KW - Non-point source pollution

KW - Phosphorus

KW - Surface runoff

KW - Drainflow

KW - Groundwater

KW - Macropores

KW - Grassland

KW - Agriculture

U2 - 10.1016/S0048-9697(00)00393-4

DO - 10.1016/S0048-9697(00)00393-4

M3 - Journal article

VL - 251-252

SP - 523

EP - 538

JO - Science of the Total Environment

JF - Science of the Total Environment

SN - 1879-1026

IS - 1

ER -