DOI: 10.23637/wrn20-soil-01
title: Dataset: Woburn Erosion Reference Experiment plot soil total C and N

description: Soil data for each plot of the Woburn Erosion Reference Experiment, 1989-1996. The soil from each plot was sampled in 1990, 1991, 1992, 1993 and 1996 and analysed for total carbon (C) and nitrogen (N) concentration (%). Total N was also measured in 1989. Data is for topsoil (0-10, 0-15 or 0-20cm) plus 50-60cm in 1992 only. This is the data described by Quinton et al, 2006. Clay content was also measured in 1996, as reported by Quinton and Catt, 2007. The experiment had eight plots, in a 2x2 factorial, with two blocks. Treatments were two directions of cultivation (cultivated and drilled parallel to the contour <i>v</i> up and down the slope) and two types of tillage (conventional tillage, residue removed <i>v</i> minimal tillage, residues retained). 

Crop yield and erosion and runoff data is published separately.
description: The experiment was situated on a sandy soil at Woburn Experimental Farm (Great Hill II/III) on a five-degree slope, which had been subject to periodic erosion since at least 1950. The eight plots were approximately 24 x 36m (0.086 ha), separated by grassed earth banks 1m wide and 30cm high which prevented runoff and eroded soil leaving the plots. Four plots were cultivated and drilled parallel to the contour, and four up and down the slope. Four plots received conventional tillage and four minimal tillage. All plots grew the same crops each year, in a rotation typical of the sandy soils of Bedfordshire. The soil was sampled on a grid with nine or 12 samples from each plot. In 1989-1991 several samples were taken from each plot and bulked together for analysis (composite samples).
description: An Excel file, 01-wrn20soil.xlsx, contains the plot soil data and treatment details, for 1989-1996. Frictionless CSV files are provided for users who prefer CSV over Excel files. A README file contains extensive metadata information.
description: **Soil total % C** was measured in sieved (2mm) air-dried soil, ground in an agate mill and analysed using a Perkin-Elmer CHN elemental analyser. 

**Soil total % N** was measured in sieved (2mm) air-dried soil, ground in an agate mill, by Kjeldahl digestion.

**Soil clay content** was measured in air-dried unground soil using the particle size distribution pipette method (Avery and Bascombe, 1982). The results are the means of two determinations for each plot. 

**Minimal tillage:** cereal straw chopped, potato haulms pulverised and retained and beet tops retained, both partially incorporated by shallow tines or discs to 10cm depth. Between crops soil was left in post-harvest condition, covered with stubble and crop residues until cultivated for the seedbed. 

**Conventional (standard) tillage:** cereal straw baled and removed, potato haulm and beet tops raked up and removed, plots ploughed with a general purpose mouldboard plough to 25cm depth. Between crops soil was in bare fallow after ploughing.
description: Plot soil C and N data are from data files provided by John Quinton. Background information was also taken from Quinton and al, 2006. Clay content data is from Quinton et al, 2007. Once the data were entered into e-RA, they were independently back-checked against the original data sheets. Summary data for heavy metals in plot soil are reported in Quinton and Catt, 2007.