Atmospheric CO2 data from the Australian Grains Free Air CO2 Enrichment (AGFACE) facility

Within the Australian Grains Free Air CO2 Enrichment (AG-FACE) research program, several facilities were established at different field sites near the towns of Horsham (36.752 S, 142.114 E; 127 m elevation), and Walpeup (35.121 S, 142.005 E; 94 m elevation) in the state of Victoria Australia from 2007 - 2017. These included: TraitFACE, SoilFACE, Walpeup-FACE, VegeFACE, and NFACE. These facilities were designed to answer a range of research questions to understand the im-pacts of elevated CO2 (e[CO2]) on crop physiology and pro-duction. To this end, FACE 'rings' (octagons) were built to el-evate atmospheric CO2 to 550 mu mol/mol expected by 2050. These rings were open structures allowing crops to grow freely, without enclosures. Each side of an octagonal ring was individually controlled by a ring-side controller that injected CO2 over crops as per the control program. Infrared Gas Analysers (IRGAs) placed at ring centres sampled air con-tinuously from 10 cm above the crop canopy, while CO2 was injected at a height 15 cm above the crop canopy. Infrared Gas Analysers (IRGAs) measured atmospheric CO2 concentration ([CO2]) during the cropping season and provided feed-back to the controller to maintain ring-centre [CO2] at 550 mu mol/mol. The [CO2] data were collected from the centre of each FACE ring from 2007 until 2017. The [CO2] within a ring was measured each second using calibrated IRGAs. Wind direction and speed were monitored continuously at 2 m above the soil surface at the centre of each ring. These measurements were also collected at the centres of a couple of ambient experimental areas (control - no rings) using the same IRGA and wind sensors. A wireless ethernet local area network (LAN) and a Visual Basic program were used to monitor and transmit data from the individual rings and control areas for data logging. Data at every 4th second and one minute average (A_MN_CO2) from each ring were logged to daily files, and only A_MN_CO2 data were combined into a seasonal cumulative file. All data recorded during the IRGA warmup period and due to equipment malfunction were removed from cleaned data files. Only A_MN_CO2 data from the rings are uploaded in the Mendeley Data Repository for this article because these data are principally used by scientists and researchers. Data columns in an individual clean file are labelled with abbreviated column names and each file includes: 1) RING, 2) DATE, 3) TIME, 4) A_MN_CO2, 5) REGULAT, 6) WIND_SPD, 7) WIND_DIR and 8) RING_SEC. A limited amount of data (2007 CO2 data at ring centres from 8 Trait FACE rings) was published previously [1]. (C) 2022 The Authors. Published by Elsevier Inc.