Methods of measuring available nutrients in West Indian soils

Summury Nine methods of measuring available soil P have been compared using dry-matter yield response and P uptake data from maize grown on 155 West Indian soils in greenhouse experiments. Olsen's (0.5N NaHCO₃) method gave the best estimates of available P and was also least sensitive to changes in soil properties (texture, pH, cation exchange capacity, and percent base saturation). Amer's resin method was almost as good except that it was unsuccessful with soils of low base saturation (< 60 per cent).