We measured pollutant losses in drainage and surface runoff from pasture grazed by cattle.

Artificial (mole-pipe) subsurface drainage was the most important pathway of nitrogen (N) loss.

Restricting autumn grazing times reduced N losses in subsurface drainage by 43%.

Surface runoff and subsurface drainage were equally important pathways of P and sediment fluxes.

Fluxes of Escherichia coli in surface runoff were greater than in mole-pipe drainage.