Sulphur in soils.II.—Determination of the total sulphur content of soil

Abstract

Published methods for the determination of total sulphur in soil are reviewed. A method is described for determining total sulphur in soil in which all the sulphur is reduced to sulphide by heating the soil with ferrum reductum. The sulphide is treated with acid and the evolved hydrogen sulphide estimated iodimetrically with standard alkaline hypochlorite solution as absorbent. The method is specific for sulphur. It has been found applicable to the determination of sulphur in soils of widely diverse origins and in many kinds of pure substances, both organic and inorganic. An error of ± 2.5% can be expected in the determination of total sulphur in soil.

Sulphur in soils. III.—A study of the readily soluble sulphate content and of the total sulphur content of soil

“…of a saturated calcium sulphate solution which has a pC value of 2.69 at 18" there are 82. 5 This supports the idea that calcium and sulphate are amongst the most important ions of humid-climate field soils, and may predominate therein ; they undoubtedly tend to dominate the ionic situation in glasshouse soils. In peat soils where calcium is likely to be deficient, other ions, especially potassium and sometimes iron, may become more important than calcium.…”