Model estimates of topsoil pH and bulk density [Countryside Survey]

Countryside Survey topsoil pH and bulk density (g cm-3) data is representative of 0 - 15 cm soil depth. Topsoil pH was measured using 10g of field moist soil with 25ml de-ionised water giving a ratio of soil to water of 1:2.5 by weight; bulk density was estimated by making detailed weight measurements throughout the soil processing procedure. For topsoil pH and bulk density data, a total of 2614 cores from 591 1km x 1km squares across Great Britain were collected and analysed in 2007. Please see Emmett et al. 2010 for further details of sampling and methods (http://nora.nerc.ac.uk/id/eprint/5201/1/CS_UK_2007_TR3%5B1%5D.pdf).

Estimates of mean values within selected habitats and parent material characteristics across GB were made using CS data from 1978, 1998 and 2007 using a mixed model approach. Please see Scott, 2008 for further details of similar statistical analysis (http://nora.nerc.ac.uk/id/eprint/5202/1/CS_UK_2007_TR4%5B1%5D.pdf). The estimated means of habitat /parent material combinations using 2007 data are modelled on dominant habitat and parent material characteristics derived from the Land Cover Map 2007 and Parent Material Model 2009, respectively. The parent material characteristic used was that which minimised AIC in each model (see Dataset Documentation).

The Countryside Survey looks at a range of physical, chemical and biological properties of the topsoil from a representative sample of habitats across the UK. Countryside Survey soils data are freely available under licence from the Environmental Information Data Centre catalogue.