title: Understanding spatial variability of soil properties: a key step in establishing field- to farm-scale agro-ecosystem experiments.
abstract: BACKGROUND
  The spatial variability of soil properties is poorly understood, despite its importance in designing appropriate experimental sampling strategies. As preparation for a farm-scale agro-ecosystem services monitoring project, the 'North Wyke Farm Platform', there was a need to assess the spatial variability of key soil chemical and physical properties.
  
  
  METHODS
  The field-scale spatial variability of soil chemical (total N, total C, soil organic matter), soil physical properties (bulk density and particle size distribution) and stable isotope ratios (δ(13) C and δ(15) N values) was studied using geostatistical approaches in an intensively managed grassland.
  
  
  RESULTS
  The scales over which stable isotopes vary (ranges: 212-258 m) were larger than those of the total nutrients, soil organic matter and bulk density (ranges: 84-170 m). Two visually and statistically distinct areas of Great Field (north and south) were identified in terms of co-occurring high/low values of several soil properties.
  
  
  CONCLUSIONS
  The resulting patterns of spatial variability suggest lower spatial variability of stable isotopes than that of total nutrients, soil organic matter and bulk density. Future sampling regimes should be conducted in a grid with <85 m distance between sampling locations to sufficiently capture the spatial variability of the measured soil properties on the 'North Wyke Farm Platform'. Consultation of the management histories of the sampled field revealed that it had previously comprised two fields with contrasting management histories, suggesting an effect of management legacy (>5 years) on the patterns of spatial variability.
authors.affiliation: Department of Geography, University of Exeter, Exeter, EX4 4RJ, UK.
authors.forename: Sabine
authors.initials: S
authors.lastname: Peukert
authors.forename: Roland
authors.initials: R
authors.lastname: Bol
authors.forename: William
authors.initials: W
authors.lastname: Roberts
authors.forename: Christopher J A
authors.initials: CJ
authors.lastname: Macleod
authors.forename: Phillip J
authors.initials: PJ
authors.lastname: Murray
authors.forename: Elizabeth R
authors.initials: ER
authors.lastname: Dixon
authors.forename: Richard E
authors.initials: RE
authors.lastname: Brazier
mesh_terms: D002244:Carbon / Q000032:analysis; D002247:Carbon Isotopes / Q000032:analysis; D017753:Ecosystem; D004784:Environmental Monitoring; D009584:Nitrogen / Q000032:analysis; D009587:Nitrogen Isotopes / Q000032:analysis; D012987:Soil / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D012987:Soil; D002244:Carbon; D009584:Nitrogen