CAN THE PLANT AVAILABILITY OF ELEMENTAL SULFUR BE ENHANCED THROUGH ITS COMBINATION WITH SEWAGE-SLUDGE AND HYDRATED LIME

Elemental sulfur (S degrees) was combined with dried anaerobically dig ested sewage sludge (DDS) and/or hydrated lime (Ca(OH)(2)) to create a possible alternative to conventional SO degrees fertilizers. These S degrees blends were studied in both powdered and pelletized form to di scern both the role of DDS as a fertilizer binder and as a potential s timulator of heterotrophic S degrees oxidation. The S degrees blends w ere visually examined to obtain general conclusions regarding surface characteristics and potential plant availability. An incubation lastin g 12 wk was used to examine the short-term release of sulfate from fin e (mean particle diameter [MPD] = 82 mu m) and coarse (MPD = 353 mu m) S degrees blends. Sulfate supply potential and the effects of S degre es pelletization were studied in the growth chamber with canola as the test crop. An apparent link existed between enhanced S degrees oxidat ion rate and a modified surface environment produced by the combinatio n of S degrees + DDS + Ca(OH)(2). Soil amendment with S degrees blends containing DDS + Ca(OH)(2) or Ca(OH)(2) showed initial oxidation rate s superior to S degrees alone. Growth chamber observations revealed hi gher canola yield and sulfate recovery with application of S degrees b lends containing DDS + Ca(OH)(2) over S degrees alone. Attempts at pel letizing the S degrees blends resulted in improved handling characteri stics, but lowered product performance due to poor dispersion in soil.