Evaluation of some soil test methods for available sulphur using cabbage as a test crop

Greenhouse studies were conducted with twenty surface alluvial soils using sulphur treatments of 0 and 40 ppm as 35S tagged (NH4)2SO4. The dry matter yield, per cent sulphur in tissue and its crop removal increased significantly due to sulphur treatment. The utilization of fertilizer sulphur and per cent sulphur in plant derived from fertilizer ranged from 28 to 57 and 55 to 80 per cent respectively. 'A' values showed highly significant correlation (r = 0.76) with percentage yield of cabbage, whereas 1N NH4OAc soluble S in soil correlated satisfactorily with percentage yield (r = 0.64) and yield of no sulphur plants (r = 0.61). The critical levels for A-value and 1N NH4OAc extractable S were 22.5 and 30.0 ppm, respectively. (author)