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ARS Home » Midwest Area » Urbana, Illinois » Global Change and Photosynthesis Research » Research » Research Project #431456

Research Project: Free Air Carbon Dioxide Enrichment

Location: Global Change and Photosynthesis Research

Project Number: 5012-21000-030-08-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Sep 15, 2016
End Date: Sep 14, 2021

Grow replicated 300 m plots (n = 4) of soybean under elevated CO2 (600 ppm) from planting until harvest.

Free Air Concentration Enrichment (FACE) consists of rings (each approximately 70 feet in diameter) of pipes that release carbon dioxide into the wind as it flows across the crop. A computer continuously measures wind speed and direction and the gas concentration within the ring to determine which pipes release the gas and how much they release. The carbon dioxide is released into the naturally moving air so that the concentration within the ring is elevated to a preset level of 600 ppm. Each ring uses on average across the season about a ton of carbon dioxide. Downwind of the rings, the added gas is diluted quickly in the flowing air so that concentrations are close to background within about 300 feet outside of the treatment ring.