[Effects of acidification and liming on organic matter leaching in forest soil]

The potential effects of acidification and liming on the dynamics of carbon pool in forest soil were studied through field experiments at Tieshanping, Chongqing in Southwest China. The changes of dissolved organic matter (DOM) concentration in soil water in different layers within three years after application of limestone or magnesite indicated that soil remediation had leaded to significant decrease of DOM in soil water from mineral layers [e.g., DOC concentration in the upper layer decreased from (20.32 +/- 3.19) mg x L(-1) in the reference plots to (15.69 +/- 2.39) mg x L(-1) in limestone plots and (11.44 +/- 1.87) mg x L(-1) in magnesite ones] as probably the results of increasing pH value and decreasing ion strength, although the DOM leaching from the litter layer was found increasing, especially in the first half year. Consequently, liming may not in longterm accelerate the transport of soil organic mater downward from the litter layer to the mineral layer, but prevent the acidified soil from DOM-leaching and thus carbon-pool losing.