The effect of hedgerow wild‐margins on topsoil hydraulic properties, and overland‐flow incidence, magnitude and water‐quality

Overland and shallow-subsurface flows from agricultural catchments are believed to contribute towards flood-risk water-quality degradation across the globe. Hedgerows commonplace features that may disrupt these rapid hydrological pathways. Research into functioning of hedgerows is very limited however, with no field-based quantitative comparison overland-flows within versus other land-uses. This research first globally observe changes in overland-flow incidence, volume water-quality, alongside topsoil hydraulic physico-chemical properties, induced by a hedgerow adjoining wild-margin grassland landscape. Observations were conducted two replicated paired-plots between bordering pasture, Cumbria, UK. Compared adjacent hedge-margins significantly reduced dry bulk-density increased porosity, median permeability factor 22–27. Overland-flow models, based on direct observations, highlight slower produce than pastures, requiring an equal or greater amount saturation before onset generation. Hedge-margins resultantly produced less volume, likely due infiltration, percolation and/or evapotranspiration. Soil also confirm pastures saturate faster hedge-margins, having extremely variable dynamics relation precipitation, whereas have more moderate consistent dynamics. ‘wash-off’ experiments store substantially nitrate (70–260%), nitrate-nitrite (640–650%), loose sediment (540–3970%) ground surface compared pastures; although further experimentation needed determine contaminant mobilization potential.