Can the plant availability of element sulfur be enhanced through its combination with sewage sludge and hydrated lime?
Sulewski, G.D. and J.J. Schoenau . 1998. Can. J. Soil Sci.78:459-466
Abstract
Elemental sulfur (S°) was combined
with dried anaerobically digested sewage sludge (DDS)
and/or hydrated lime (Ca(OH)2) to create a
possible alternative to conventional S° fertilizers.
These S° blends were studied in both powdered and
pelletized form to discern both the role of DDS as a
fertilizer binder and as a potential stimulator of
heterotrophic S° oxidation. The S° blends were visually
examined to obtain general conclusions regarding surface
characteristics and potential plant availability. An
incubation lasting 12 wk was used to examine the
short-term release of sulfate from fine (mean particle
diameter [MPD] = 82 pin) and coarse (MPD = 353 gm) S°
blends. Sulfate supply potential and the effects of S°
pelletization were studied in the growth chamber with
canola as the test crop. An apparent link existed between
enhanced S° oxidation rate and a modified surface
environment produced by the combination of S° DDS
Ca(OH)2. Soil amendment with S° blends
containing DDS Ca(OH)2 or Ca(OH)2
showed initial oxidation rates superior to S° alone.
Growth chamber observations revealed higher canola yield
and sulfate recovery with application of S° blends
containing DDS Ca(OH)2 over S° alone.
Attempts at pelletizing the S° blends resulted in
improved handling characteristics, but lowered product
performance due to poor dispersion in soil.
Key Words
Elemental sulfur, sewage sludge, oxidation, plant availability
