Management Considerations for Acid Soils with High Phosphorus Fixation Capacity

Abstract

Phosphorus (P) fixation is generally understood as the transformation of soluble forms of P into less soluble ones after they react with the soil. This chapter examines the occurrence and magnitude of high P fixation and the management practices. Acid soils which fix large quantities of P are invariably medium- to fine-textured soils high in oxides and hydroxides of iron and aluminum. Phosphate rocks are reactive in acid soils and usually cost one-third to one-fifth per unit of P as superphosphate. Soils with high P fixation capacity occur in both the tropical and temperate latitudes. Massive initial P applications represent an attractive management strategy because the fixation problem is substantially reduced for some period. The different component of the low-input management strategy consists of adapting plants to the soil's limitations rather than the traditional approach of adapting the soil to meet crop requirements.