Abstract:Drying and rewetting cycles caused by rainfall and irrigation influence the availability of soil nutrient. In order to estimate the effects of drying-rewetting intensity on nutrient availability, three moisture treatments (rewetting to 60%,45% and 30% WHC) were designed in this study compared with a constantly moist control (CM, 60% WHC during the whole incubation period). The pH of DW1 (rewetting to 60% WHC) was 0.25~0.45 lower than other treatments while the differences among other treatments were not significant. After incubation, the DOC in CM decreased by 20.01%, while decreased by 37.04%~41.36% in drying-rewetting treatments, and there were no significant differences among different intensities. The ammonium nitrogen decreased by 18.19%~42.02% in the drying-rewetting treatments, but the reduction came down with the increasing intensity. The nitrate nitrogen increased sharply in each treatment but the increase came down with the increasing intensity. The ammonium nitrogen and nitrate nitrogen in DW2 (rewetting to 45% WHC) were consistent with CM. Available P and available K had little change after the incubation, but available P in DW2 was lower than other treatments as well as available K in DW3 (rewetting to 30% WHC). Drying-rewetting cycles led to a reduction of DOC and ammonium nitrogen and an increase of nitrate nitrogen but had little effect on pH, available P and available K. Following the growth of drying-rewetting intensity, soil pH and ammonium nitrogen gradually increased, while nitrate nitrogen and available K decreased.