Isotope and morphometrical evidence reveals the technological package associated with agriculture adoption in western Europe

This study aimed to reconstruct the environmental conditions and the crop management practices and plant characteristics when agriculture appeared in western Europe. We analyzed oak charcoal and a large number of cereal caryopsides recovered from La Draga (Girona, Spain), an early (5300 to 4800 cal. BC) agricultural site from the Iberian Peninsula. The carbon isotope discrimination (Δ13C) values of oak, the dominant forest species in the region, indicates prevalence of a wet climate at the site. Further, we reconstructed crop management conditions, achievable yield, and crop characteristics through the analysis of Δ13C, nitrogen isotope composition (δ15N), nitrogen content, and the reconstructed weight of wheat and barley caryopsides, following protocols developed by our team [Araus et al., Nat. Commun. 5, 3953 (2014)] and comparison of these parameters with present-day organic agriculture in the region. In parallel, a regional perspective was achieved through the study of wheat and barley grains of seventeen Neolithic sites from the western Mediterranean. The results suggest that rather than small-garden cultivation, a more extensive agriculture was practiced under good water availability and moderate manuring. Moreover, results from La Draga evidence that grain weight and spike morphology were comparable to contemporary cereals. Growing conditions and the prevalence of improved crop traits indicate that agriculture was fairly consolidated at the time it reached the western edge of Europe.

This research was supported in part as follows: by the PID2019-109254 GB-C2 and PID2022-138307OB-C21 projects from the Ministerio de Ciencia, Innovació y Universidades, Spain; from the Swiss NSF (http://www.snf.ch/) Project PP00P1_170515; and through diverse support Downloaded from https://www.pnas.org by Universitat de Lleida on June 9, 2025 from IP address 193.144.12.133. from Generalitat de Catalunya (Spain) including two ICREA (Institució Catalana PNAS  2024  Vol. 121  No. 32 e2401065121 https://doi.org/10.1073/pnas.2401065121 11 of 12 de Recerca i Estudis Avançats) Academia fellowship (2022 call), the Grant CLT009/18/00050, the Reference Group S74_23R (Gobierno de Aragón) and the AGAUR (Agència de Gestió d’Ajuts Universitaris i de Recerca) Fellowships 2021 SGR 00190, 2021 SGR 00501, 2021 SGR 00688, and 2021 SGR 00995. We also thank Ajuntament de Banyoles