Studying ancient crop provenance: implications from δ¹³C and δ¹⁵N values of charred barley in a Middle Bronze Age silo at Ebla(NW Syria)

Abstract

The discovery of a storeroom full of barley and other cereals (L.9512) in the proto-historic site of Ebla has provided a unique opportunity to study the centralized storage system of the early city-state from a different perspective. Epigraphic evidence available within the site reveals a complex system of taxation which included gathering grain tributes from satellite sites and redistributing semi-finished products such as flour. In this paper, we intend to explore the possibilities of a combined approach to studying the storage system, based on estimated barley grain volumes and δ(13)C-δ(15)N analyses. This approach is used to distinguish between grain from different harvesting sites and to identify any grain cultivated using special agricultural practices (e.g. manuring or irrigation). The basic assumption for this kind of analysis is that the growth-site conditions, natural or anthropogenic, of harvested cereals are reflected in their grain size and δ(13)C-δ(15)N values. Since the remains found in the storeroom were charred, the first task was to evaluate the effect of carbonization on the δ(13)C-δ(15)N and the size of the grains. Thus, the effect of charring was tested on modern samples of Syrian barley landraces. Once it had been ascertained that fresh grains reduced to charred remains retain their original biometric and isotopic traits, the ancient material was examined. Thirteen groups were identified, each characterized by a specific average volume and specific carbon and nitrogen values. The analysis revealed that what had first appeared to be a homogeneous concentration of grain was in fact an assemblage of barley harvested from different sites.

Carbon and Nitrogen Isotopic Survey of Northern Peruvian Plants: Baselines for Paleodietary and Paleoecological Studies

“…Nitrogen isotopic compositions were highly variable, particularly for potato, which most likely reflected variable local growing conditions (soil fertility, type of manure used) rather than any biochemical or physiological process specific to any particular plant species. Ultimately, the best source of baseline isotopic data for paleodietary studies may be from archaeobotanical remains [27], [201]–[203], provided that preservation of original carbon and nitrogen isotopic compositions can be demonstrated. Considerable work has been done in this regard for the isotopic composition of bone collagen [204]–[208] and to a lesser extent hair keratin [209], but a solid set of parameters for detecting preservation versus alteration of original plant carbon and nitrogen isotopic compositions have not yet been determined.…”

From necessity to choice: dietary revolutions in west China in the second millennium BC

“…Previous research has shown that the δ 15 N values of grains depend on soil conditions, such as the type of soil-N, the balance between enzyme demand and external concentration, and the manuring effect (cf. Fiorentino et al 2011;Aguilera et al 2008). The difference found in δ 15 N values between the Neolithic and historical bones in Mozuizi may be understood in the context of change through time of the soil content.…”

Stable carbon isotope analysis as a direct means of inferring crop water status and water management practices

“…In recent years, greater emphasis has been placed on direct means of inferring water conditions from archaeological crop remains themselves, through phytolith (Jenkins, Jamjoun and Al Nuimat 2011;Madella et al 2009;Mithen et al 2008;Piperno 2006;Rosen and Weiner 1994) and stable carbon isotope analysis (Araus and Buxó 1993;Araus et al, 'Changes' 1997a;Araus et al, 'Identification' 1997b;Araus, Febrero et al 1999;Araus, Ferrio et al 2007;Ferrio et al 2005;Fiorentino, Caracuta, Calcagnile et al 2008;Fiorentino, Caracuta, Casiello et al 2012;Flohr, Mülder and Jenkins 2011;Heaton et al 2009;Riehl 2008;Riehl, Bryson and Pustovoytov 2008;Stokes, Mülder and Jenkins 2011;Voltas, Ferrio et al 2008). Isotopic investigations have tended to interpret results in relative terms, for example using stable carbon isotopes to determine whether certain time periods were wetter or drier than others.…”

“…In addition, it is only through the study of present-day crops, grown under known conditions, that the relationship between plant carbon isotopes, specific water conditions and water management practices can be explored. To date, such present-day studies have been conducted for only a handful of crop species, grown in few locations, under highly controlled experimental conditions (Araus et al, 'Identification' 1997b;Araus, Febrero et al 1999;Araus, Villegas et al 2003;Fiorentino, Caracuta, Casiello et al 2012;Flohr, Mülder and Jenkins 2011;Stokes, Mülder and Jenkins 2011).…”