Repository logo
 

Crop water status from plant stable carbon isotope values: A test case for monsoonal climates

Published version
Peer-reviewed

Type

Article

Change log

Authors

O’Connell, TC 
Jones, MK 
Singh, RN 
Petrie, CA 

Abstract

jats:p Stable carbon isotope analysis is increasingly used in archaeology as an indicator of crop water status and/or water management regime. While the technique shows promise, robust modern baseline studies are required to inform and validate archaeological interpretations. Here, we test stable carbon isotope values as a crop water status proxy in a monsoonal climatic context for the first time. Specifically, we test the relationship between grain stable carbon isotope values (δjats:sup13</jats:sup>Cjats:subgrain</jats:sub>), water availability, irrigation and soil type in barley ( Hordeum vulgare L. (Zohary and Hopf.)) in north-west India, with the aim of deriving a locally-appropriate model for isotopic interpretation. We test this relationship across a substantial rainfall gradient (200–1000 mm/year) and find a negative logarithmic relationship between climatic water availability and δjats:sup13</jats:sup>C. However, there is significant noise in the relationship, and we report δjats:sup13</jats:sup>Cjats:subgrain</jats:sub> variation of over 3‰ amongst samples drawn from similar climatic contexts. Soil type, irrigation type and irrigation frequency have no clear modifying effects. We conclude that: (1) barley stable carbon isotope values can act as an archaeological water status proxy in monsoonal areas, but will be most sensitive in areas receiving <450 mm rainfall per year; and (2) it is not possible to precisely infer water management regimes. On the basis of our results, we propose guidelines for archaeological barley stable carbon isotope interpretation in north-west India and analogous monsoonal climates. </jats:p>

Description

Keywords

archaeology, barley, irrigation, stable carbon isotope analysis, water management, water stress

Journal Title

Holocene

Conference Name

Journal ISSN

0959-6836
1477-0911

Volume Title

31

Publisher

SAGE Publications
Sponsorship
British Council in India (IND/CONT/06-07/172E)
European Research Council (648609)