Soil moisture and Electrical Resistivity Tomography (ERT) measurements within the top metre of soil at Church Field, Chimney Meadow National Nature Reserve. Church Field lies on a clay lens which overlies surrounding sand and gravel soils. Apart from the A and B horizons, the clay was found to be fairly homogenous down to the maximum depth of 1.1m of the access pit. On the 1:250,000 Soil Map of South East England the location falls into the soils category 832 Kelmscott Association which comprise mostly permeable fine loamy soils over limestone gravel and variably affected by groundwater and with some risk of flooding. However, on the more detailed 1:25,000 scale Sand and Gravel Resources Map of the Thames Valley the clay lens is depicted as Oxford Clay substrate without sand and gravel cover, surrounded by sand and gravel terraces cropping out at the surface.
Publication date: 2011-09-27
Data collected in the field by CEH. Samples were collected from a soil pit dug 13.75m from the north end of the ERT transect and offset 1.0m to the west of the transect line. Fixed volume soil samples were collected in stainless steel rings of dimension 100mm deep x 99mm I.D. at sample depth in increments of 10cm up to 1.0m. At each depth, two samples were collected. The samples were stood in a water bath until they reached an equilibrium (saturated) weight. The samples were then placed in (1) a sand bath (2) a sand/kaolin bath (3) pressure vessels set at a range of suctions in order to progressively dry out the samples. Water-release curves were constructed for each soil level.