Abstract: Aimed to approach the responses of soil element geochemical cycling in paddy field ecosystem to elevated atmospheric CO₂, a rice/wheat FACE (Free-Air Carbon Dioxide Enrichment) platform was utilized to study the effects of elevated atmospheric CO₂ on the concentrations of Cl^-, CO₃^2-, HCO₃^-, SO₄^2-, NO₃^-, and dissolved inorganic phosphorus (DIP) in soil solution at different growth stages of rice. Under effects of elevated atmospheric CO₂, the SO₄^2- concentration in soil solution decreased while the HCO₃^- concentration was in adverse, and the effects were more obvious at the soil depth 15 cm than at 5 cm. In the meantime, the NO₃^- and DIP concentrations in soil solution had a decreasing trend, while the CO₃^2-and Cl^- concentrations had no obvious variation pattern. The affecting mechanisms of elevated atmospheric CO₂ on the anion concentration in soil solution were also analyzed.  

Key words: Wild soybean, Salt tolerance, Ionic distribution, Selective transportation