Oxidation of elemental sulphur and acidulation of calcareous orchard soils in southern British Columbia

Abstract

The capacity of soils to oxidize S was measured by incubation with finely divided elemental S in 13 calcareous orchard soils from the southern interior of British Columbia. Sulphur oxidation rates ranged from 3.4 to 26 μg S cm-2 d-1. The magnitude of pH decrease in response to added S varied inversely with initial CaCO3 content and silt content and directly with sand content. Incubation studies with one calcareous orchard soil indicated that finely divided S was more effective over time than other acidulants (FeSO4, Al2(SO4)3 and H2SO4). In a field study on the same soil, incorporated fine S was oxidized to a much greater extent during a 2-year period than was incorporated bentonitic grandulated S. However, when surface applied, they were oxidized equally but slowly. -Authors