Study site description
The assessment of buffer strip efficacy was undertaken on experimental plots located at the Rothamsted Research North Wyke site in Devon, U.K. (50°46’31.3”N 3°55’41.6”W). This site has a mean annual rainfall of 1032 mm y-1, a mean maximum temperature of 13.5°C and mean minimum temperature of 6.7°C (1982 – 2019; see Table 1 for mean monthly values). The site is situated upon a bedrock of clay bearing shales of the Carboniferous Crackington Formation, with overlying soils represented by a poorly drained Hallsworth series pelo-stagnogley soil (FAO classified as stagni-vertic cambisol; Harrod & Hogan 2008). The stony clay loam topsoil comprises 16%, 48% and 36% of sand, silt, and clay, respectively. Below the topsoil layer, the subsoil is impermeable to water and is seasonally waterlogged; most excess water moves by surface and sub-surface lateral flow across the clay layer (Orr et al., 2016), with the experimental area having a slope of 8°.