Assessing the ploughzone: The impact of cultivation on artefact survival and the cost/benefits of topsoil stripping prior to excavation

Thousands of archaeological sites in Europe lie under the ploughzone. Previous studies and experiments have highlighted the impact that arable agriculture has on the preservation of archaeological sites, yet the ploughzone has also been shown in some cases to preserve important information. In this study, the value of the ploughzone was assessed through metal detecting and through sieving of the ploughsoil directly over one of the most productive areas for artefacts at an important early medieval site in Scotland. The purpose of the assessment was to gauge the extent to which removing the topsoil may lead to the loss of important information and to evaluate the extent to which strip-and-map approaches to excavation might contribute to information loss. It is the largest such experiment of its kind in Scotland and the experiment allowed an assessment of the type and condition of artefacts found in excavation compared to that in the ploughsoil. The study showed very few artefacts survived in the topsoil at this site with certain artefact types entirely absent. The study also showed the significant impact that even light ploughing has had on categories of objects such as metalworking moulds. The conclusions are that while cropmarks remain a diminishing resource, strip-and-map allows rapid assessment of these sites and where artefact densities are low this approach is unlikely to lead to loss of significant information.