
%0 Journal Article
%A Sholeh, 
%A Lefroy, Rod D. B. 
%A Blair, Graeme J. 
%T Effect of nutrients and elemental sulfur particle size on elemental sulfur oxidation and the growth of <emph type="2">Thiobacillus thiooxidans</emph>
%J Australian Journal of Agricultural Research
%D 1997/04/15
%V 48
%N 4
%P 497-502
%K sulfur, oxidation, particle size, Thiobacillus, nutrients.
%R https://doi.org/10.1071/A95055
%U https://www.publish.csiro.au/paper/A95055 
%X Elemental sulfur (S) has many attractions as a fertiliser but it must be oxidised to sulfate before it is plant available. Two laboratory incubation experiments with a high S sorbing basaltic soil (Haplohumult) from Walcha, New South Wales, are reported here. The first experiment was conducted to study the effect of – P and other nutrients on the oxidation of elemental S and the growth of Thiobacillus thiooxidans. The second experiment studied the effect of phosphorus (P) rate, elemental S particle size, and elemental S form on the oxidation of elemental S at different times.  There were significant differences between treatments in the percentage and amount of elemental S oxidised, with the lowest oxidation occurring during the 6-week incubation in the P treatment, which represented 1·8% of the applied S compared with 16·0% when all nutrients were supplied. There was a significant linear relationship between T. thiooxidans population at the end of the incubation period and the amount of elemental S oxidised.  The oxidation of elemental S was higher when fine (50–150 µm) particle size elemental S was used, compared with coarse (150–250 µm) elemental S. There was no clear difference in oxidation rate between ground and recrystallised elemental S. The S oxidation rates recorded in these experiments were compared with those predicted by an S oxidation model and found to be in close agreement. 
