Rock phosphate and superphosphate were compared as fertilizers for pastures on acidic soils. Superphosphate was better initially, but both had good long-term effects. Gypsum as a sulfur fertilizer had low residual value. When plant growth is limited, phosphorus fertilizers retain their value better. The conversion of inorganic phosphorus to organic forms by plants is crucial for phosphorus availability. Mixing rock phosphate and superphosphate was tested, with results discussed.