New stable isotope geochemical approach documents grain production and manuring in the High Middle Ages

Isotope analysis, particularly for the determination of δ13C and δ15N in archaeobotanical remains, is a recognized method within the field of archaeology. Until now, the primary focus of these analyses has been on archaeobotanical remains directly related to dietary practices. The significant impact of the Cistercian Order on the European agricultural landscape, and its far-reaching ecological consequences, has been well documented. However, the use of isotopic analysis for determining land-use based on present-day soils remains unexplored. The study at hand focuses on a Cistercian court, utilized from the 13th to the 15th century. The lands of this court, along with its surrounding regions, have been extensively surveyed. The isotopic analysis of the anthropogenically influenced soils is compared to approximately 400 archaeobotanical, soil, and sediment samples collected globally. The comparative analysis reveals the potential to ascertain through the presence of the C3 cycle and evidence of medieval fertilization, that the area was used for cereal cultivation and fertilization. The results of our study indicate that the medieval Cistercians employed the landscape primarily for grain production rather than pastoralism.