Sulfur and molybdenum fractionation in marine and riverine alluvium paddy soils

• Main Authors: Zakikhani, Hamed, Yusop, Mohd Khanif, Musa, Mohamed Hanafi, Othman, Radziah, Soltangheisi, Amin
• Format: Article
• Language: English
• Published: Taylor & Francis 2016
• Online Access: http://psasir.upm.edu.my/id/eprint/52431/1/Sulfur%20and%20molybdenum%20fractionation%20in%20marine%20and%20riverine%20alluvium%20paddy%20soils.pdf; http://psasir.upm.edu.my/id/eprint/52431/; http://www.tandfonline.com/doi/full/10.1080/09542299.2016.1212674

Intermittently submergence and drainage status of paddy fields can cause alterations in morphological and chemical characteristics of soils. We conducted a sequential fractionation study to provide an insight into solubility of Sulfur (S) and Molybdenum (Mo) in flooded alluvial paddy soils. The samples (0-15 and 15-30 cm) were taken from marine and riverine alluvial soils in Kedah and Kelantan areas, respectively, and were sequentially extracted with NaHCO3, NaOH, HCl, and HClO4-HNO3. Total S in upper and lower layers of Kedah and Kelantan ranged between 273 and 1121 mg kg-1, and 177 to 1509 mg kg-1, respectively. In upper layers and subsoil of Kedah, average total Mo were 0.34 and 0.27 mg kg-1, respectively. Average total Mo in Kelantan were 0.25 mg kg-1 (surface layer) and 0.28 mg kg-1 (subsoil). Cation exchange capacity (CEC) was positively correlated with plant available amounts of Mo in upper layers of Kedah area. Also, total and medium-term plant-available S was correlated with total carbon (C) at lower layers of Kelantan soil series. But in surface layers of Kelantan soil series, CEC was strongly correlated with total and medium-term plant-available S. Our results indicates that the influence of flooding conditions on soil S and Mo contents in paddy fields may cause long-term changes in S and Mo chemical reactivities.