Dark oxidation of water in soils

Journal article, 2013

We report the release of oxygen (O-2) under dark conditions in aerobic soils. This unexpected process is hidden by respiration which constitutes the dominating reversal O-2 flux. By using (H2O)-O-18 in different soils, we confirmed that (OO)-O-16-O-18 and O-18(2) released under dark soil conditions originated from added (H2O)-O-18. Water is the only large-scale source of electrons for reduction of CO2 in soils, but it has not been considered as an electron donor because of the very strong oxidation system needed. A high share of soil inorganic material seems to favor the release of O-2.