Some aspects of sulphur as a nutrient for pastures in New England soils.

Abstract

A severe deficiency of sulphur has been found in a soil derived from granite and another from basalt on the Northern Tablelands of New South Wales. Large increases in the growth of subterranean clover were obtained by the application of sulphates of sodium, magnesium, or calcium, equivalent to sulphur at a rate of 64 lb per acre, but about 85 per cent. of this increase was obtained with 30 lb per acre. The deficiency is thought to be widespread. There was no significant benefit on established clover from the application of phosphorus alone on either soil, nor did the combination of phosphorus with sulphur on the basaltic soil produce a greater yield than that obtained from sulphur alone. Clear evidence has been obtained that the residual value of sulphur, provided as calcium sulphate in superphosphate, is low on a pasture stocked heavily with sheep under Northern Tableland conditions. A marked decline in production due to sulphur deficiency occurred when annual dressings of 2 cwt superphosphate were discontinued in the third or fourth years. It is important when assessing the residual effect of superphosphate to appreciate the relative significance of the phosphorus and sulphur in the fertilizer and the factors governing the loss of sulphur, from the soil. Results obtained are discussed in relation to the influence of climatic conditions (especially rainfall) and land use (cultivation, stocking, and industrialization) on sulphur status.