The Braunschweig FACE Project

In the coming decades the concentration of the greenhouse gas carbon dioxide (CO2) will increase as a consequence of climate change. Model calculations assume 550 ppm (parts per million) in the middle of this century (currently 385 ppm). CO2 is the most important “nutrient” for plants, which draw them from the air and convert them through photosynthesis into biomass. Does an increase in the CO2 concentration in the atmosphere lead to an increase plant growth (CO2 fertilization effect), and how will other metabolic parameters, for example water consumption and quality, be influenced? Does the biological diversity on arable fields change through these processes? If one wishes to make predictions on plant production in the future, these are essential questions.

In order to find an answer here, the FACE Project (Free Air Carbon Dioxide Enrichment) has been running on the test fields of the vTI in Braunschweig for many years. Circular portions of the fields, with a diameter of 20 meters, are gassed with CO2 for the entire vegetation period with the help of computer-controlled valves, so that within these areas, CO2 concentrations of about 550 ppm exist. Case wise, it was possible to simulate variations in fertilization or drought/increased temperatures. In this manner it was possible to study the impact of a future increase in CO2 concentration together with summer drought under real field conditions. Here the purpose is to make recommendations to adapt agriculture to future climate scenarios.

These extremely complex testing facilities are found in only a few places worldwide, Braunschweig is the only FACE location for arable crop systems in Europe. While initially three-part crop sequence (winter barley, sugar beets, winter wheat) was studied, in 2007 and 2008 maize followed, and 2010 and 2011 various genotypes of sorghum as an energy plant are planned.

A short report of results ti date can be found here.