Sulphur Forms Distribution in Soil Profiles of Different Locations of Southwestern Nigeria

Non-sulphur nitrogen fertilizer use, soil profile, pH and physico-chemical properties contribute to soil sulphur deficiency so distribution of different forms of sulphur in soil profiles of twelve locations in Ogun and Oyo states, Southwestern Nigeria was investigated to know their status with respect to the soil depths of samples derived from sedimentary and igneous/metamorphic rocks comprising of Alfisols (8 profiles) and Ultisols (4 profiles). These were collected at four different soil depths of 0-20 cm, 20-40 cm, 40-60 cm and 6080 cm respectively from savanna and forest vegetation zones. The soil physico-chemical properties of pH, organic carbon, total nitrogen, CEC, clay, silt and sand were determined using standard analytical methods and correlated with the different forms of sulphur (available, organic and total). The results showed that both the available, organic and the total S were positively correlated with these parameters (r = 0.905**) and (r = 0.590**) respectively. The status of the different forms of S fell below the critical limits of 10 mg/kg and as a result, farmers are advised to apply sulphur-containing fertilizers in these soils so as to obtain maximum yields in their crops particularly for leguminous plants.