Transformation characteristics of sulfur forms in acid sulfate soils under different soil water conditions
不同土壤水分条件下酸性硫酸盐土硫形态转化特征

Aimed to detect the quantitative impact of soil water condition on the transformation of sulfur forms in acid sulfate soils (ASS), a simulation test was made with 8 treatments. The results indicated that water was an important factor affecting the transformation processes. Wet but not inundated or over dried condition was benefit to the oxidation of pyrite S and the formation of water soluble S (WS-S) and exchangeable S (Ex-S) in ASS. In the three treatments with different inundated and drained off cycles, soil pyrite S content averagely decreased 1.29-3.20 g x kg(-1) during a single drained off period, while soil WS-S and Ex-S contents averagely increased 0.90-1.63 and 0.58-1.47 g x kg(-1), respectively. During inundated period, soil pyrite S content was relatively stable, but soil WS-S and Ex-S contents were decreased significantly due to the dilution of water. It was suggested that the total S (mainly WS-S) of ASS was discharged in drainage process, and the accumulative amount of the discharge and the transformation of the S forms were associated with the length of the inundated and drained off cycles. The dynamics of Jarosite S, organic S and element S in all treatments were also discussed here.