Sulfur Fractions, Distribution and Sorption Characteristics in Some Soils of Ogun State, Southwestern Nigeria

Sulfur (S) fractions, distributions and sorption characteristics of some soils in Ogunstate, Southwestern Nigeria, were evaluated in ten different locations, the area lies with in the Derived Savannah and forest agro-ecological zone. Result showed available, adsorbed, organic and total S ranged from 3.9 to 19.8, 16.3 to 36.6, 214.9 to 412.9 and 248.8 to 446.6 mg kg(-1) respectively. Organic S constituted 86.4 to 93.4% of total S. The mean status of available S was slightly above the critical limit of 10 mg kg(-1). All fractions of S maintained significant positive correlation (p <= .05) with each other and total organic carbon, while available and adsorbed S had significant and negative correlation with soil pH, total nitrogen, available phosphorus and calcium. The S sorption behavior of the soils varied and increased with increase in S concentrations of equilibrium solution. The isotherm model for the ten locations was S-curved type. Sorption data were fitted to Langmuir and Freundlich sorption isotherms. Langmuir equation was best fitted to the S adsorption data in the ten locations except soils from Owode, Odeda and Ikenne. Langmuir and Freundlich parameters (sorption maxima, binding energy and maximum buffering capacity affinity constant and slope) were significantly correlated with some soil properties.