Isotopic Evidence for Changes in Cereal Production Strategies in Iron Age and Roman Britain

Abstract

Following the Roman conquest, agricultural production in Britain faced increasing demand from large urban and military populations. While it has long been thought that this necessitated an increase in agricultural production, direct archaeological evidence for changes in cultivation practices has been scarce. Using a model that conceptualises cereal farming strategies in terms of intensive or extensive practices, this paper is the first study to address this question using carbon and nitrogen stable isotope data of crop remains. We report δ 15 N and δ 13 C values from 41 samples of spelt, emmer and barley from Bronze Age, Iron Age and Roman Stanwick (Northants., UK), in order to assess the intensiveness of arable farming and investigate shifts in cultivation practices in prehistoric and Roman Britain. The results demonstrate a decline in δ 15 N in the Roman period, suggesting that farming practices moved to lower levels of manuring and, by implication, became more extensive. δ 13 C values are comparable in all periods, supporting the suggestion that changes observed in human stable isotope data between the Iron Age and Roman period are best explained by dietary change rather than a shift towards higher δ 13 C values in plants at the base of the food chain.

New Perspectives on the Medieval ‘Agricultural Revolution’

“…Direct evidence for crop rotation is currently limited. Isotopic analysis of emmer, spelt and barley remains from Iron Age and Roman Stanwick, Northamptonshire, showed no statistical difference in the δ 15 N or δ 13 C (beyond the barley-wheat offset) values for the Iron Age or Roman period (Lodwick et al, 2021). Either they were grown in rotation from the Iron Age, or no move towards rotation of these crops in different fields took place.…”

“…The late Roman innovations proposed by Jones (1981; have, however, largely fallen by the wayside. More generally, agricultural intensification continues to be identified in broader studies of the period, but with an intended meaning of higher overall production rather than shifts in crop husbandry practices per se (Lodwick et al, 2021).…”

“…In summary, no definitive evidence is available for a Roman mouldboard plough in Britain, and more widely this innovation is seen as occurring beyond the borders of the Roman empire (Henning, 2016, 29). However, heavy clay soils were being cultivated in the Roman period, in the Nene Valley and elsewhere in the Central Belt Lodwick et al, 2021), whilst stinking chamomile (Anthemis cotula L.), an indicator of clay soil cultivation, is widespread in archaeobotanical assemblages across different regions (Lodwick, 2017a, table 2.17). The question remains of how extensively one can cultivate with an ard.…”

“…The Stanwick stable isotope study does show a statistically significant decline in δ 15 N values from the Iron Age to the Roman period. With no environmental reasons for this decline, a decrease in the quantity of manure applied and hence extensification appears the most likely explanation (Lodwick et al, 2021). More broadly, autecological analysis of weed seeds suggests an increase 39 Composition of rural storage samples based on grain counts.…”

Animal husbandry between the Roman times and the High Middle Ages in central Europe: a biometrical analysis of cattle, sheep and pig

“…A close control of feeding times and foodstuffs, as well as keeping animals in stables or stys, are possible factors behind livestock size increase in the Roman period. However, some works have suggested that extensive agricultural practices were practised in different parts of the Roman Empire (MacKinnon 2001;Albarella et al 2019;Lodwick et al 2020). The extent to which agricultural practices were more or less intensive or extensive (in terms of inputs per unit area) might have varied greatly depending on various factors such as climate, soil, or demographic density, and understanding the particularities of this would require a multidisciplinary approach that is well beyond the scope of this paper.…”