Mineralization of organic sulfur in fout soils (Black soil, Cinnamon soil, Yellow brown earth and Red soil) was studied by
means of an open-incubation system at 20℃ and 30℃ in aerobic and
waterlogging conditions, separately. Results showed that the amount of S mineralized at 30℃ was significantly greater than at 20℃ (P<0.01), and also greater amounts of S were mineralized in the aerobic condition than in the waterlogging condition in black soil, cinnamon soil, yellow brown earth and red soil. Cumulative amount of S mineralized and the percentage as soil organic S of the four soils incubated in the aerobic condition at 20℃ and 30℃ was 17.53-24.35mg kg-1 and 34.20-54.33mg kg-1, 2.5%-6.5% and 5.0%-14.5%,
respectively, and in the waterlogging condition at 20℃ and 30℃ 18.14-21.15 mg kg-1and 26.86-30.63 mg kg -1, 2.6%-5.6% and 4.0%-7.7%, respectively. The ratio of the amount of S mineralized at 30℃ to that at 20℃ was 1.85-2.23 and from 1.28-1.71 in aerobic and waterlogging condition, respectively. The potentially mineralizable S pool (S0) calculated by the exponential equation and the reciprocal equation at 20℃ and 30℃ in the aerobic condition was 17.82-24.88 mg kg -1, 17.83-27.70 mg kg -1 and 35.81-61.28 mg kg -1, 41.49-80.00 mg kg-1, respectively. The potentially mineralizable S pool (S0) calculated by the exponential equation and the reciprocal equation at 20℃ and 30℃ in the waterlogging condition was 17.50-21.49 mg kg -1, 19. 19-22.50 mg kg-1 and 28.26- 35.87 mg kg-1, 26.59-34.25 mg kg-1, respectively. The organic S mineralization rate constant (K) and the time required to mineralize 50% of S0 (K1) varied with soil and incubation temperature. Both the exponential equation and reciprocal equation can be used to calculate organic S mineralization potentials and rate constants. Ester sulfate (C-O-S), carbon-bonded S(C-S) and unidentified organic S(UO-S) were all mineralized during the incubation period.