Because of uncertainty about the effects of rising atmospheric carbon dioxide levels on crop growth, water use, grain yield and quality, there is a need to obtain data from field experiments conducted in the Australian grain belt. This project will design and commission a national free air carbon dioxide enrichment (FACE) array consisting of a core facility of 8*12 m diameter elevated carbon dioxide enrichment rings at Horsham with a corresponding set of control (ie ambient CO2 rings), supplemented by one smaller systems each of 8*4 m diameter rings and 8 control areas located in the low rainfall Mallee region of Victoria. These facilities will provide researcher access to unique and high quality field facilities for wheat production in Australia. This facility will then generate detailed data sets on the field response of wheat to elevated carbon dioxide levels including interactions with water, nutrition and temperature, and these data will then be made available to crop systems modellers to use to calibrate and extend existing crop simulation models to incorporate possible outcomes into future industry strategies.