Changes in soil sulphur fractions during incubation with and without added sulphur

Open Access
Publisher Website
Google Scholar
Abstract
Three soils of contrasting sulphur status were incubated with 35S-gypsum under growth chamber conditions. Levels of five different S fractions and the HI-reducible fraction were monitored periodically. During incubation added S was progressively immobilised to as much as 50% while indigenous S was simultaneously mineralised. An apparent steady state was reached at about 70 days for only the S extracted by Ca(H2PO4)2-H2O and NaH2PO4-HOAc. Control treatments with and without basal fertiliser additions showed a similar apparent steady state of mineralisation which was contributed largely by the HI-reducible S fraction The E values were strongly correlated with the indigenous S extracted by Ca(H2PO4)2-H2O and NaH2PO4-HOAc.