Premium
SULPHATE REDUCTION IN WATERLOGGED SOILS
Author(s) -
BLOOMFIELD C.
Publication year - 1969
Publication title -
journal of soil science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.244
H-Index - 111
eISSN - 1365-2389
pISSN - 0022-4588
DOI - 10.1111/j.1365-2389.1969.tb01568.x
Subject(s) - chemistry , soil water , sulfur , sodium dithionite , dithionite , solubility , alkali soil , soil ph , environmental chemistry , inorganic chemistry , soil science , geology , organic chemistry , enzyme
Summary To study the factors that influence the release of free H 2 S, flooded soils were incubated with plant material and either sodium sulphate or elemental sulphur. Residual sulphate, FeS and H 2 S were measured throughout the reaction. Less free H 2 S was evolved from a periodically waterlogged soil than from a well‐drained soil of comparable HC1‐ and dithionite‐soluble Fe content. With a readily soluble synthetic Fe 2 O 3 as the source of Fe, a slight excess of Fe over the SO 4 2– equivalent sufficed to prevent loss of H 2 S. The native organic matter in the well‐drained Rothamsted top‐soil seemed to have no effect in promoting loss of H 2 S, but the FeS:H 2 S ratio was strongly influenced by the nature of the plant material used as the source of energy. With either Na 2 SO 4 or S, considerably more free H 2 S was evolved with lucerne than with rice blade. With S, the pH of the incubated mixtures was close to that of the nominally S‐free system, whereas with Na 2 SO 4 the mixture became quite alkaline. More free H 2 S was evolved under the more alkaline conditions obtained with Na 2 SO 4 , which suggests that it is the initial mobilization of Fe that governs the distribution of the reduced S, rather than the pH‐solubility relations of FeS. An oxidized surface layer is very effective in retaining sulphur in the soil.