Deposition of sulphur from the atmosphere and the sulphur balance in four soils under grass

Abstract

SUMMARY: The sulphur balance in eight lysimeters containing four different soils under grass was examined over a 4-year period during which the annual mean concentration of sulphur dioxide (SO₂) in the air at the site decreased from 30 to 14 μg/m³. The amounts of sulphur harvested in the grass and lost in drainage were set against additions in fertilizer, rainfall and from dry deposition. A decline in annual dry-matter yield was accompanied by a decrease in the concentration of sulphur in the herbage and an increase in the ratio of nitrogen to sulphur. It was concluded that atmospheric sources and soil reserves may become insufficient to meet the sulphur requirement of grassland.