An Improved Method of demonstrating the Distribution of Sulphides in Peat Soils

Abstract

HYDROGEN sulphide is produced under certain conditions in soils and may be an important factor in governing the distribution of higher plant species in the field1. Burgeff2 describes a simple method of demonstrating the presence of sulphides in peat soils. He obtained a visual measure of the distribution with depth from the formation of silver sulphide on silver-plated brass rods. Clymo3 used polished silver wires for a similar purpose. Work at this research station on changes in redox potentials in depth and time at four peat bog sites has required better definition of sulphide distribution than either of these methods provides. The degree of discoloration of polished silver ranges from pale gold through brown to black, and it is difficult to observe the lighter end of the colour scale on a curved surface. Furthermore, there are often considerable horizontal variations in sulphide occurrence in the field and a large number of wires would be necessary to measure such variations. By using silver plates these difficulties can be overcome.