Control of CO2 inside Australian grains free air carbon dioxide enrichment (AGFACE) facility

Abstract

The Australian Grains Free-Air Carbon dioxide Enrichment (AGFACE) facility was established at Horsham (36°45′07″S latitude, 142°06′52″E longitude), Victoria, Australia in 2007 to conduct research under Australian conditions with the aim to generate field response data in broad-acre wheat to elevated levels of CO2. Carbon dioxide concentrations within the rings in the AGFACE facility are computer controlled, using inputs of sensed carbon dioxide concentration, wind speed and direction at the centre of each ring. The control system uses a number of pneumatic valves and associated fittings driven by a control algorithm. On average, the control system at the Horsham site has enabled the AGFACE r..