Key Points
- Four barley cultivars (DASH, CRBA125, Sherwood and Omaka) were grown with, and without, irrigation and nitrogen (N) fertiliser at Lincoln during the 2009-10 season.
- Dash and CRBA 125 had a higher water use efficiency (WUE) than Sherwood and Omaka. This means that these cultivars produced more yield using less water. Adding N increased WUE but irrigating did not; non-irrigated crops had a higher WUE than irrigated crops.
- Without irrigation, adding N increased average water use by 3%. With irrigation, adding N increased water use by 9%.
- A new technique has been developed to determine the WUE of barley cvs. The stable carbon isotope composition of leaf-respired CO2 was closely correlated with WUE. This relationship could be used to identify cereal cultivars with higher WUE.
- In future, breeders could develop cultivars with specific WUE characteristics suited to a range of growing conditions and management practices. For example, higher water use efficiency would be desirable where irrigation is restricted.