Effect of Phosphorus and Sulphur on Their Availabilities in Soils

An incubation experiment on sandy (Fatehpur series of Typic Ustipsamment) and loam (Nabha series of Typic Ustochrept) soils with five rates of phosphorus and sulphur (0–100 mg kg⁻¹ soil) at field capacity soil water content and 25 ± 1°C showed that available phosphorus increased significantly with the increasing rates of phosphorus and tended to decline with time up to 30 days. Sulphur increased the available phosphorus from the native as well as applied source. The synergistic effect of phosphorus and sulphur on extractable phosphorus was significant in sandy soil only. Available sulphur increased significantly with its increasing rates and increase in incubation period. The increasing rates of phosphorus also increased the available sulphur. The synergistic effect of phosphorus and sulphur on the extractable amounts of sulphur was significant in both the soils.