Forest Hill Agricultural Research Station Soil Map

This is the linework for the detail soil survey of the FHARS. This soil survey is part of the infrastructure program for the research station. The soil survey guides field plot layouts and the siting of infrastructure. It also assists with the instrumentation of the site and is a baseline for temporal changes.\nLineage: This soil survey follows the principals of a free survey (McKenzie & Grundy, 2008), a conventional qualitative methodology. Free survey is based on the establishment of a local soil classification, in this case using soil profile classes (Powell, 2008) as the taxonomic unit. Soil profile classes (SPC) were identified from soil profile descriptions of 138 soil cores taken on the research farm. Each core was up to 1.5 m in length and 0.049 m in diameter. The recognised soil profile classes were correlated with other existing local classifications, in this case the soil profile classes of the Soils of the Lockyer Valley Alluvial Plains (Powell et al., 2002).\nAfter soil profile classes were established for the research farm, the extent of each soil profile class on the research farm was mapped using primarily aerial photography as a base to the mapping. Soil boundaries were delineated using the 138 soil core observations made during field work and a large amount of other data. The soil boundary between mapping units is rarely an abrupt change (as shown on a map) but often represents a diffuse change over a large distance. Where a diffuse boundary is expected, the line has been placed near the centre of the change. Each map unit is represented by one soil profile class. This was possible given the density of the soil observations. 138 observations were made over 66 hectares, which is 1 observation per 0.5 hectare. This is equivalent to a 1: 10,000 scale ‘detailed’ soil survey (Gallant et al., 2008).