Data from the Arizona FACE (Free-Air CO2 Enrichment) experiments on sorghum at ample and limiting levels of water supply

Authors: Kimball, Bruce; OTTMAN, MICHAEL - University Of Arizona; PINTER JR., PAUL - Retired Non ARS Employee; Wall, Gerard - Gary; LEAVITT, STEVEN - University Of Arizona; CHENG, LI - University Of Arizona; Conley, Matthew; La Morte, Robert; TRIGGS, JONATHAN - Grand Canyon University; GLEADOW, ROSLYN - Monash University

Submitted to: Open Data Journal for Agricultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2021
Publication Date: 9/28/2021
Citation: Kimball, B.A., Ottman, M.J., Pinter Jr., P.J., Wall, G.W., Leavitt, S.W., Cheng, L., Conley, M.M., La Morte, R.L., Triggs, J.M., Gleadow, R. 2021. Data from the Arizona FACE (Free-Air CO2 Enrichment) experiments on sorghum at ample and limiting levels of water supply. Open Data Journal for Agricultural Research. 7:1-10.

Interpretive Summary: From 1998-1999 ARS researchers from the U.S. Water Conservation Laboratory, Phoenix, AZ (now moved to U.S. Arid-Land Agricultural Research Center, Maricopa, AZ) and the University of Arizona, Tucson, AZ, along with several other collaborating scientists conducted two FACE (free-air CO2 enrichment) experiments on sorghum at ample and limiting levels of water and nitrogen. Since then, data from these experiments have been requested numerous times for subsequent modeling and meta-analytic studies about the likely effects of global change on future sorghum productivity. Therefore, this manuscript, along with six associated data files, have been assembled for publication in an “open” data journal so than anyone in the future will have easy access to this valuable dataset. The dataset is comprehensive and includes management, soils, weather, physiology, phenology, growth, yield, and cyanide data. Using carbon isotopic tracing, carbon flows were measured from the air to the plants to sequestration in the soil. This research will benefit all consumers of sorghum-based food, including meat from animals that are fed sorghum.

Technical Abstract: Two free-air CO2 enrichment (FACE) experiments were conducted on sorghum (Sorghum bicolor (L.) Möench, a C4 grain crop) at Maricopa, Arizona, U.S.A. during the 1998 and 1999 summer growing seasons. They were conducted at ample and limited (50% of ample) supplies of water. A large and varied set of data on plant, soil, and microclimatic responses to the elevated CO2 and its interactions with the water supply was collected. The dataset assembled herein consists of many of these data, including those generally used for model validation, such as management, soils, daily and 15-minute weather, physiology (net photosynthesis, plant water potential, relative water content), phenology, biomass growth, leaf area, yield, canopy temperatures, energy balance, evapotranspiration, soil moisture, reflectance and vegetation indices, and absorption of photosynthetically active radiation. Partitioning of nitrogen between nitrate and cyanide, which affects toxicity of the sorghum forage to livestock, was measured. In addition, isotopic methods were used to trace carbon flows in both FACE and Control plots from atmosphere to plant material to soil carbon pools. The dataset is useful for validation of sorghum growth models, which get used to predict likely future sorghum productivity given projected global climate change.