The evaluation of the elemental sulfur and gypsum effect on soil pH, EC, SO_4-S andavailable Mn content

摘要

Three levels (0,400 or 800 mg S kg~(-1)) of elemental sulfur (S°) or gypsum (CaSO_4.2H.,0) were applied to soil samples. The soil samples were incubated and analyzed weekly during an 8-week period to determine changes in soil pH, EC value, SO_4-S andavailable Mn contents. Regardless of sources, sulfur application continuously decreased the soil pH and increased the electrical conductivity of soil during the eight week experimental period. The lowest pH value (pH 7.04) was observed with 800 mg S kg~(-1) elemental sulfur application, and the highest EC value (1330.33 uS cm') was obtained with 800 mg S kg~(-1) gypsum application. The tested soil SO_4-S content variations depended on the incubation time, sulfur sources and application levels. SO_4-S content of soil showed alinear increase throughout the 8 week incubation as S° was applied. The highest SO_4-S value of 53.34 mg kg~(-1) about 20 folds higher than that of control was observed with 800 mg S kg~(-1) elemental sulfur application. Incubation time, sulfur sources and the application levels had significant effect on the available Mn contents.