Ramon Buxó

Stable carbon and nitrogen isotopes and quality traits of fossil cereal grains provide clues on sustainability at the beginnings of Mediterranean agriculture

We present a novel approach to study the sustainability of ancient Mediterranean agriculture that combines the measurement of carbon isotope discrimination (Delta(13)C) and nitrogen isotope composition (delta(15)N) along with the assessment of quality traits in fossil cereal grains. Charred grains of naked wheat and barley were recovered in Los Castillejos, an archaeological site in SE Spain, with a continuous occupation of ca. 1500 years starting soon after the origin of agriculture (ca. 4000 BCE) in the region. Crop water status and yield were estimated from Delta(13)C and soil fertility and management practices were assessed from the delta(15)N and N content of grains. The original grain weight was inferred from grain dimensions and grain N content was assessed after correcting N concentration for the effect of carbonisation. Estimated water conditions (i.e. rainfall) during crop growth remained constant for the entire period. However, the grain size and grain yield decreased progressively during the first millennium after the onset of agriculture, regardless of the species, with only a slight recovery afterwards. Minimum delta(15)N values and grain N content were also recorded in the later periods of site occupation. Our results indicate a progressive loss of soil fertility, even when the amount of precipitation remained steady, thereby indicating the unsustainable nature of early agriculture at this site in the Western Mediterranean Basin. In addition, several findings suggest that barley and wheat were cultivated separately, the former being restricted to marginal areas, coinciding with an increased focus on wheat cultivation.

Agronomic conditions and crop evolution in ancient Near East agriculture

The appearance of agriculture in the Fertile Crescent has propelled the development of Western civilization. Here we investigate the evolution of agronomic conditions in this region by reconstructing cereal kernel weight and using stable carbon and nitrogen isotope signatures of kernels and charcoal from a set of 11 Upper Mesopotamia archaeological sites, with chronologies spanning from the onset of agriculture to the turn of the era. We show that water availability for crops, inferred from carbon isotope discrimination (Δ13C), was two- to fourfold higher in the past than at present, with a maximum between 10,000 and 8,000 cal BP. Nitrogen isotope composition (δ15N) decreased over time, which suggests cultivation occurring under gradually less fertile soil conditions. Domesticated cereals showed a progressive increase in kernel weight over several millennia following domestication. Our results provide a first comprehensive view of agricultural evolution in the Near East inferred directly from archaeobotanical remains.

An integrated perspective on farming in the early Neolithic lakeshore site of La Draga (Banyoles, Spain)

Abstract A combined analysis of the faunal and charred plant macroremains from the early Neolithic lakeshore site of La Draga (Banyoles, Spain) is presented. The aim was to characterise the farming strategies practiced by the first Neolithic communities in the north-east of the Iberian Peninsula in terms of their degree of intensity. The joint discussion of the data allowed the observation that permanent plots could have been kept, that a high harvest would have been practiced and that a low-scale processing of the crop could have taken place within the domestic space, where the grain would be stored. This type of crop husbandry would permit the livestock to access the fields and graze the stubble, which would result in the manuring of the plots. Herds were kept close to the dwellings and different management and consumption practices were observed between the larger and the smaller animals. Smaller animals were probably produced and consumed at a household scale while larger animals would require a cooperative management and consumption. It is concluded that the available evidence points towards an intensive mixed farming model.

Productivity in prehistoric agriculture: physiological models for the quantification of cereal yields as an alternative to traditional approaches

Agriculture has been the basis of social development. For this reason, a proper estimation of yield in prehistoric agriculture is of importance in many disciplines. After highlighting the limitations of the traditional approaches used for estimating yields in the prehistoric agriculture of the Old World, based mainly on archaeological, anthropological and ethnographic assumptions and evidences, this study discusses models with a physiological and agronomic bias. These models rely on a thorough knowledge of the biological factors that determine the crop yield, and involve the analysis of archaeological plant remains produced by prehistoric agricultural systems. The evaluation of ancient cereal yields based on the analysis of carbon isotope discrimination from fossil grains is proposed as a promising approach.

Prehistoric Occupation of Banyoles Lakeshore: Results of Recent Excavations at La Draga Site, Girona, Spain

Abstract Recent research at the Neolithic site of La Draga on the edge of Banyoles Lake (Girona, Spain) has documented evidence for the occupation of the lakeshore from the final quarter of the sixth millennium cal BC. Excavation during 2010 and 2011 identified at least two episodes of occupation. The oldest episode includes wooden structures, which were superseded and overlain by a paving of travertine blocks during the younger phase. Archaeological materials, artefacts, and pottery styles indicate a level of continuity between the two phases of construction and occupation. Both episodes can be attributed to the Cardial Neolithic. Investigation of the underwater part of the site resulted in the discovery of the first wooden tools from the site and therefore from the prehistory of Iberia.

The Application of Systematic Sampling Strategies for Bioarchaeological Studies in the Early Neolithic Lakeshore Site of La Draga (Banyoles, Spain)

Abstract This paper presents the multi-disciplinary sampling strategy that has been applied at the archaeological site of La Draga during the last three fieldwork campaigns (2010–2012). A preliminary evaluation of the results is presented in order to discuss the efficiency of the strategy in answering the outlined scientific questions. The strategies applied for faunal remains (one hundred per cent recovery), wood remains (selective sampling) and charcoal remains (random sampling of twenty-five fragments per square) proved to be successful. The anticipated levels for ichthyofauna, entomofauna and non-ligneous plant macroremains were not attained using this sampling strategy. Some explanations for this are proposed (e.g. high degree of erosion of the archaeological layer). Further guidelines for future work are established. This strategy could be applied to other Mediterranean wetland sites.

Farming Practices in the Early Neolithic According to Agricultural Tools: Evidence from La Draga Site (Northeastern Iberia)

La Draga is an open-air settlement located on the shoreline of Lake Banyoles in the Northeast of the Iberian Peninsula. To date, two occupation phases have been differentiated, both attributed to the Early Neolithic (5300–4900 cal BC). The proximity of the lake has meant that a large part of the site has been covered by the water table; as a consequence organic materials are well preserved. The preservation of wooden artefacts offers an excellent opportunity to study the techniques and crafts developed in the first Neolithic villages. This chapter presents the wooden tools related to agricultural practices. This assemblage consists of 45 pointed sticks, 24 of which can be interpreted as digging sticks according to ethnographic and archaeological parallels and the results of a specific experimental program, and 7 sickle handles, one of which holds a flint blade still inserted in its original position. The information these implements provide for the knowledge of the first agriculture is discussed and compared with data supplied by several archaeobotanical proxies. The two approaches are seen to contribute complementary data allowing a more comprehensive reconstruction of the farming practices of Early Neolithic communities in the Western Mediterranean.