Trials to Identify Soil Cultivation Practices to Minimise the Impact on Archaeological Sites (Defra project number BD1705) Effects of Arable Cultivation on Archaeology (EH Project number 3874) Known collectively as: ‘Trials’ Appendix 4: Studying the effects of different cultivation systems on archaeological earthworks December 2010 Client: English Heritage and Defra Issue No: 2 OA Job No: 1879 Appendix 4 The effects of different cultivation systems on archaeological earthworks By K Spandl, C Champness, M L Dresser, M J Hann, and R J Godwin Edited by P Booth and K Spandl Oxford Archaeology and Cranfield University i 14/12/10 Oxford Archaeology and Cranfield University Final report Appendix 4 The effects of different cultivation systems on archaeological earthworks 1 Introduction ..................................................................................................................... 1 1.1 Background .................................................................................................................................1 1.2 Introduction to the project...........................................................................................................2 1.3 Aims of the project.......................................................................................................................2 2 Agriculture and earthworks - background ................................................................... 4 2.1 Affects of cultivation on earthworks ............................................................................................4 2.2 Changes in earthwork management ............................................................................................9 2.3 Why do we need to protect cultivation-damaged earthworks?..................................................10 2.4 Rates of destruction...................................................................................................................11 2.5 Previous experimental earthwork studies..................................................................................12 3 Methodology................................................................................................................... 16 3.1 Introduction...............................................................................................................................16 3.2 Construction of the earthworks .................................................................................................16 3.3 Monitoring Stations...................................................................................................................18 3.4 Cultivation of the earthworks ....................................................................................................19 3.5 Monitoring and recording .........................................................................................................20 3.6 Final recording .........................................................................................................................20 4 Results............................................................................................................................. 21 4.1 General......................................................................................................................................21 4.2 Barrows .....................................................................................................................................21 4.3 Ridge and furrow.......................................................................................................................24 4.4 Ridge .........................................................................................................................................25 4.5 Slope..........................................................................................................................................26 5 Discussion ....................................................................................................................... 28 5.1 Transponder and soil movement ...............................................................................................28 5.2 Glass and sand indicator pits....................................................................................................29 5.3 Comparison between earthwork types.......................................................................................30 5.4 Summary of comparison between cultivation types...................................................................31 5.5 Survival of features below earthworks ......................................................................................32 6 Validity of Results.......................................................................................................... 34 7 Summary ........................................................................................................................36 Oxford Archaeology and Cranfield University ii 14/12/10 Oxford Archaeology and Cranfield University Final report 8 REFERENCES .............................................................................................................. 38 Figure list Figure 4.1 Layout of earthworks in the field at Cranfield Figure 4.2 Photograph of ridge and Furrow, pre-cultivation Figure 4.3 Photographs of barrows, pre-cultivation Figure 4.4 Photographs of ridge, pre-cultivation Figure 4.5 Construction and reprofiling of the earthworks Figure 4.6 Position of all monitoring stations within the earthworks, pre-disturbance Figure 4.7: Photographs of glass and sand indicator pits and disturbance Figure 4.8 Earthwork tillage Figure 4.9 Contour survey over non-inversion barrow years 0-10 Figure 4.10 Contour survey over non-inversion barrow years 15-30 Figure 4.11 Below ground disturbance - non-inversion barrow - years 0-10 Figure 4.12 Below ground disturbance - non-inversin barrow - years 20-30 Figure 4.13 Contour survey over mouldboard plough barrow years 0-10 Figure 4.14 Contour survey over mouldboard barrow years 15-30 Figure 4.15 Below ground disturbance - mouldboard plough barrow Figure 4.16 Cross Sections through mouldboard plough and non-inversion barrows Figure 4.17 Contour survey, direct drill barrow years 0-10 Figure 4.18 Contour survey, direct drilling barrow years 15-20 Figure 4.19 Pre-and post contour survey fallow barrow Figure 4.20 Contour survey, ridge and furrow years 0-10 Figure 4.21 Contour survey, ridge and furrow years 15-30 Figure 4.22 Below ground disturbance - ridge and furrow - years 0-1 Figure 4.23 Below ground disturbance - ridge and furrow - years 5-10 Figure 4.24 Below ground disturbance - ridge and furrow - years 15-20 Figure 4.25 Below ground disturbance - ridge and furrow - years 25-30 Figure 4.26 Cross Sections through ridge and furrow earthwork Figure 4.27 Contour Survey over ridge years 0-10 Figure 4.28 Contour Survey over ridge years 15-30 Figure 4.29 Below ground disturbance - ridge - years 0-1 Figure 4.30 Below ground disturbance - ridge - years 5-10 Figure 4.31 Below ground disturbance - ridge - years 15-20 Figure 4.32 Below ground disturbance - ridge - years 25-30 Figure 4.33 Cross Sections through the ridge - non-inversion tillage Figure 4.34 Cross Section through the ridge - mouldboard plough Figure 4.35 Contour Survey and below ground disturbance on the slope years 0-10 Figure 4.36 Contour Survey and below ground disturbance on the slope years 15-30 Figure 4.37 Re-excavation of indicator pits Figure 4.38 Post-cultivaton condition of indicator pits Table list Table 4.1: Recorded rates of truncation on earthworks Table 4.2: Earthwork statistics Table 4.3: Summary of height changes in earthworks Table 4.4: Summary of height changes Sub-appendix Appendix 4A Cosmic Risk assessments Oxford Archaeology and Cranfield University iii 14/12/10 Appendix 4 The effects of different cultivation systems on archaeological earthworks 1 Introduction 1.1 Background 1.1.1 Britain has a diverse and rich cultural heritage that is still visible within the arable landscape. The 'humps and bumps' seen within agricultural fields can reflect a wide range of archaeological sites; prehistoric barrows (burial mounds), the ramparts of Iron Age hillforts, Roman forts, medieval castle mounds, moats, lanes and evidence of previous agriculture in the form of ridge and furrow, field boundaries and lynchets etc. These earthworks cover a considerable time span and provide a visual link to our past. They are essential elements of our cultural landscape, and represent important educational and heritage resources. The loss of earthworks, historical farm buildings and field boundaries - the visible components of heritage - from the landscape, constitutes a lessening of individual regional character and reflects the spread of a more homogeneous modern agricultural landscape. 1.1.2 Rimmington (2004 pp 3) provides a convenient summary of why earthworks are important: Like all archaeological and historical remains, archaeological earthworks are a finite resource and any damage is irreversible and results in the loss of archaeological deposits, information and form. But it is not just for their archaeological value that archaeological earthworks are important. They are also important (significant); • for their contribution to the landscape • for recreational use • for their associations with people, memories, beliefs and events • and often for their ecology 1.1.3 Earthworks are also important in offering protection to potentially well-preserved