Distribution of Sulphur in Soils Formed from Different Parent Materials in Southern Nigeria

Abstract

A study on the profile distribution of sulphate - sulphur (SO₄-S) and the relationship with some soil properties was carried out in three soils namely, Oxic paleudalfs in Akure area, Rhodic paleudults in Benin area and Arenic paleudults in Sapele area of Southern Nigeria. Six depths in each profile were considered ( 0-15, 15-30, 30-45, 45-60, 60-75 and, 75-90cm).Results showed that the range of sulphate - sulphur in the soil profiles was 2.11 – 5.28 mg kg^-1 in oxic paleustalfs , 0.47-1.55 mg kg^-1 in the Rhodic Paleudults and 3.75 – 12.36 mg kg^-1 in the Arenic paleudults. The Oxic paleustalfs and Rhodic paleudults were found to be deficient in SO₄-S assuming 8.50mgkg^-1 S as critical level in surface horizon. Sulphate sulpur (SO₄-S) decreased as depth increased but at 45-60 and 60-75cm there was a slight increase in Oxic paleustalfs. In Rhodic paleudults SO4-S decreased from the surface up to 75 – 90 cm. However in Arenic paleudults SO₄-S increased in depth up to 30 – 45 cm before a decrease was experienced. The highest value for SO₄-S was recorded in Arenic paleudults at 30-45cm with a value of 12.36mg kg^-1. Correlations analysis revealed that SO₄-S correlates with organic carbon in Oxic paleustalfs (r = 0.805); Na in Oxic paleustalfs and Rhodic paleudults (r = 0.803 and r = 0.893 respectively) and Mg in Rhodic paleudults (r = 0.795).