A field trial was conducted for 3 years to evaluate phosphate rocks and phosphate rock/sulphur granules as fertilizers for permanent pastures. Two reactive phosphate rocks, North Carolina (USA) and Chatham Rise (New Zealand), and an unreactive Florida (USA) were used. The materials were applied to a highly phosphate retentive allophanic soil of medium to high phosphorus status. Single superphosphate was employed as the standard fertilizer. The fertilizers were applied at four rates including a control in the first year and again in the third year. The field design enabled measurement of residual effects as well. All the plots received blanket applications of sulphate. The rate of dissolution of phosphate rock was measured by determining soil inorganic phosphate fractions at the highest rate of fertilizer application.