Land Management & Natural Hazards Unit	SOIL
European Commission	Joint Research Centre	Institute for Environment and Sustainability		EU Soils Web Site
Soil Atlas of Europe

Introduction

Soil and cultural heritage Many of the activities of our ancestors can still be recognized through detailed studies of the soil. In fact, the soil is one of our main sources of information on the history of man before he was able to write. Soil as a medium for preserving artefacts and treasures When digging the soil for gardening, farming or constructing buildings, artefacts, treasures or other evidences of human activities are often exposed. Different soil types preserve these remains in various ways. In wet soil types such as Histosols and Gleysols, the lack of oxygen (anaerobic state) slows down the decomposition of organic matter. In these soil types the remains of animals can be found with hunting marks from arrows or spears. Well preserved human bodies have been excavated from moors and bogs. In some communities, people were executed and buried in the moors as a religious act. The anaerobic conditions preserve the bodies very well and several thousands of years later they are excavated with skin, flesh and clothes still present and sometimes it is even possible to investigate the food content in the stomach giving us an idea of what they were eating just before they died. Wooden constructions, such as poles for bridges, boats and wooden tools can be preserved giving us valuable information on the level of technology at that time.

In well drained soil such as Chernozems, Luvisols and Podzols, organic artefacts will decompose rapidly while metallic items such as weapons and ornaments can be preserved for longer periods. The aggressiveness of the soil to metal can vary among soil types and the climatic conditions. Acid soil is slightly more aggressive, rusting iron artefacts faster than neutral to slightly acid soil. In wet humid climates, decomposition rates are faster than in a cold arid environment. Pottery, on the other hand, seems to be rather stable in all soil types. Treasure found in the soil – this ceremonial helmet was discovered in a 7th Century Anglo-Saxon ship burial in Sutton Hoo, UK (British Museum). The soil profile as an archive The development of characteristic horizons in the soil can provide valuable information on human life in ancient times Agriculture practices Past farming practices can be recognized in the soil profile. Innorthwest Europe, especially in the Netherlands and Germany, a special man-made soil type, known as plaggen soil, has developed as a result of a special agricultural system. On the strongly leached, acid sandy outwash plains and moraines, Podzols have developed underneath a vegetation cover of heather (Calluna vulgaris). The farmers used the heather and the uppermost centimetre of the soil as bedding in the stables. The dropping from the animals, mixed with the bedding, was later used as manure on the nearby fields, slowly building up a thick humus rich soil layer rich in nutrients and soil water. These fields provide a relatively high and stable crop production compared to the surrounding land.  A typical plaggen soil with a very deep man-made humus layer (from the Netherlands) (HBM).

Careful study of the soil at the border between the uppermost humus coloured soil horizon and the yellowish-brown subsoil below can provide important information on previous human activities. In plaggen soil, spade marks are a distinct feature while in other areas orthogonal marks from ploughing with ards (oxen-pulled ploughs) are common. In some regions, humus coloured marks can be found indicating the positions of postholes for wooden houses thus telling us about the location of former settlements. Criss-crossing plough furrows made about 3300 years ago in Denmark (HBM). Soil processes in burial mounds Some man-made soil constructions, such as burial mounds, allow certain soil processes to operate that lead to well-developed soil horizons. These horizons, under special circumstances, can change the chemical environment in such a way that extraordinary conditions can develop for the preservation of human bodies and grave goods. In the South Scandinavian Bronze Age (1300-1400 BC), many thousands of burial mounds were constructed in Denmark, southern Sweden and northern Germany. They were about 15 metres in diameter and 3-4 metres in height but some were much larger with diameters up to 70 metres. They were built of sods over one or a few stone beds on which oak log coffins containing the bodies of presumably high ranking people were placed. A modern experiment to reconstruct a Bronze Age burial mound that develops iron pans (HBM). In some cases, as the result of a special construction method for burial mounds, iron pans have developed both above and beneath the core of the mound and, in this way, totally encapsulating the core. When the mounds are excavated, the core appears bluish or black due to a lack of oxygen and contains a lot of water, while the surrounding mantle is normally brown or yellowish-brown and dry. The core contains large quantities of un-decomposed organic matter while plant material on the sods of the surrounding mantle is decomposed.

A burial mound with the blue core described in the text (HBM). The main burials are normally found within the core. When excavated more than 3000 years after interment, well-preserved oak log coffins have been uncovered. By this process, some of the most remarkable discoveries from prehistoric southern Scandinavia have been made, as corpses, costumes, food, weapons and other implements are extremely well preserved. The existence of the lower iron pan protects the soil below the mound against leaching and this buried soil profile, called a palaeosol, can provide valuable information on the state of farmland soils in the past. A 3400 year old oak coffin from a burial mound in Egtved, Denmark. The soil conditions have allowed the coffin to survive the passage of time in a remarkable state of presentation. The tree used to make the coffin was felled in the year 1370 BC (HBM). Soil mapping and cultural heritage Soil maps are a valuable tool for explaining the location of past settlements. Matching the density of settlements to areas with good soil for farming is a tested technique. However, such soil might not necessary be what we consider today as the best soil. Communities with low agricultural technologies may have preferred sandy soil to loamy and clayey soil because of tillage problems. Mapping soil chemistry can be used for finding previous settlements, fields or industrial production places such as iron smelting. Sampling soil for phosphorus has been used to infer previous settlements while augering can be used to identify burial mounds. Techniques such as metal detecting and geomagnetism are valuable tools for discovering treasures in the topsoil and former structures, now buried beneath the soil.

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