Cultivation with deliberation: cereals and their growing conditions in prehistory

The subject of this study is the evaluation of the relationship between cereals grown in prehistory (ca. 5500 BC–AD 600) and environmental conditions during their cultivation on the land that is now the Czech Republic. Charred cereal macroremains were taken from 84 archaeological sites. The representation of species at individual sites was assessed with regard to site altitude, average temperature, precipitation, length of the growing season, soil types and soil productivity within a 1 km buffer zone around each archaeological site. The suitability of using present day environmental data to describe past environmental differences among archaeological sites was verified by expressing environmental conditions using Ellenberg indication values of macroremains of wild taxa. The results of the cereals-environmental conditions analysis show that the most important factor for the crop choice was the period of time of its cultivation. After eliminating the effect of time and length of the growing season, soil quality and altitude become conclusive variables, however with different importance in various periods. The main differences between the macroremain assemblages are represented by the varying proportions of cultivated wheats and barley. In the Neolithic (Proto–Eneolithic) there was no observable effect of environmental factors on the cereal composition. In the Middle Eneolithic–Middle Bronze Age soil type was the main factor in the selection of barley or emmer. In the Late Bronze–Early Iron Ages precipitation, altitude and Chernozems were the decisive factors influencing cereal cultivation while in the Late Iron Age–Migration Period heat load index, precipitation, and the proportion of Fluvisols were the primary determinants. It seems that prehistoric cereal varieties had ecological needs similar to present-day species and the selection of crops took place with respect to local conditions and an effort to achieve an optimum yield.