Determinants of the accuracy of using carbon isotopes in estimating water use efficiency of selected cereal and legume crops: A global perspective

Field assessments of crop water use efficiency (WUE) are resource-consuming since they require simultaneous assessment of the total amount of water assimi- lated by crops for biomass and/or grain production. Alternative methods exist, such as estimating the carbon isotopic ratio ( 13 C/12 C) of the crop's leaf, above- ground biomass, or grain samples. There is limited information on the deter- minants of the accuracy of carbon isotopes in estimating water use efficiency between crop types and...