The infrastructure of the NWFP farm‐scale experimental system was established in 2010 on the North Wyke Farm in the southwest of England (50°46′10″N, 3°54′05″W); it is described in detail by Orr et al. (2011 ). The NWFP comprises three individual farmlets, each of approximately 21 ha, designed to test the productivity and environmental sustainability of contrasting temperate grassland beef cattle and sheep systems. Each of the three farmlets consists of five catchments that range in size from 1.62 to 8.08 ha. Each catchment is hydrologically isolated through a combination of topography and a network of 9.2 km of French drains (800‐mm deep trenches that contain a perforated drainage pipe backfilled to the surface with 20–50 mm clean granite, carbonate‐free, stone chips) that was constructed at the edges of the catchments. Each catchment is equipped with monitoring sites for rainfall, soil moisture, discharge and water physicochemical properties. There is also a single site for the collection of meteorological data. Six of the 15 catchments have field divisions providing 21 fields in total across the NWFP. (See Figure S1 in Supporting Information for a map of the farmlets).
The NWFP is on a ridge at 120–180 m above sea level; the land slopes to the west to the River Taw and to the east to one of its tributaries, the Cocktree stream. A digital surface model (DSM) and digital terrain model (DTM, Figure1 ) have been produced from LiDAR (light detecting and ranging) data (Ferraccioli et al., 2014 ). The soil (Harrod & Hogan, 2008 ) belongs predominantly to two similar series, Hallsworth (Dystric Gleysol) and Halstow (Gleyic Cambisol) (Avery, 1980 ), which comprise a slightly stony clay loam topsoil (approximately 36% clay) that overlies a mottled stony clay (approximately 60% clay), derived from underlying Carboniferous culm rocks. 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 to be intercepted by the bounding drainage system at the edge of each catchment. (See Figure S2 in Supporting Information for a map of the principal soil series).
From 1984 to 2013, the mean and median annual precipitation at North Wyke was 1040 and 1031 mm, respectively. This had a distribution with an interquartile range from 922 to 1146 mm. Over this 30‐year period, the distribution of the minimum daily temperatures had an interquartile range from 3.4 to 10.2°C, whereas the distribution of the maximum daily temperatures had an interquartile range from 9.6 to 17.2°C. North Wyke has a large and consistent amount of rain in summer, which is characteristic of the major agricultural grassland areas in the west of the UK.
The NWFP is on a ridge at 120–180 m above sea level; the land slopes to the west to the River Taw and to the east to one of its tributaries, the Cocktree stream. A digital surface model (DSM) and digital terrain model (DTM, Figure
From 1984 to 2013, the mean and median annual precipitation at North Wyke was 1040 and 1031 mm, respectively. This had a distribution with an interquartile range from 922 to 1146 mm. Over this 30‐year period, the distribution of the minimum daily temperatures had an interquartile range from 3.4 to 10.2°C, whereas the distribution of the maximum daily temperatures had an interquartile range from 9.6 to 17.2°C. North Wyke has a large and consistent amount of rain in summer, which is characteristic of the major agricultural grassland areas in the west of the UK.
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