1. General Considerations 5
2. Possibilities and Limitations 8
2.1 Phosphates in the Soil 8
2.2 Phosphorus in Plants 8
2.3 Dynamics of Phosphorus in the Soil 9
2.4 Phosphorus Supplied by Fertilizer 11
2.5 Phosphate Rock for Direct Application 13
2.6 Plant Response to Phosphate Rock 17
2.7 Economic Considerations 20
2.8 Distribution of Soils Suited for Phosphate Rock Application 22
3. Summary and Conclusions 25
4. References 26