Sulfur dynamics in acidic soils during incubation with externally added elemental sulfur

Acidic soils lack sulfur (S), and only minimal data is available on the dynamics of S fractions in low pH soils.Soil sulfur is positively correlated with pH and clay content.It is important to study the transformation of sulfur with respect to different clay contents and pH levels to ascertain the sustainability of sulfur in the future and to choose between different kinds of fertilisers depending upon soil type.A total of 21 acidic soils having different pH and clay contents were selected and incubated for sixty days in a laboratory at ambient room temperature with five levels of S, i.e., 0, 20, 40, 60, and 80 kg/ha.After sixty days of incubation in the laboratory, soil samples were analysed for the contents of available, watersoluble, heat-soluble, organic, and total sulfur.The S fractions were all incremental with increasing amount of applied S, and the maximum content occurred at the rate of 80 kg S/ha.As compared to other S fractions, water-soluble S was the lowest recorded fraction of S.During the study of 21 soil samples where external sulfur was not added, all sulfur fractions increased over incubation except for organic sulfur, which reduced as it mineralised to other forms of sulfur.