Efficiency of Soil and Fertilizer Phosphorus Use. Reconciling Changing Concepts of Soil Phosphorus Behaviour with Agronomic Information

The efficient use of phosphorus (P) is essential to many agricultural and environmental issues. These include maintaining or improving the P fertility of soils by the judicious use of P fertilizers and other sources of P, such as organic manures including animal manures, composts and biosolids. There is also the need to conserve the finite global P resource. This bulletin reviews, analyses and synthesizes information on the efficient use of soil and fertilizer P. It presents information on the plant availability of soil and fertilizer P, with an emphasis on soil plant interactions. The focus is on the changing concepts of the behaviour of both soil and fertilizer P and on the need to define and assess their recovery and, thus, P-use efficiency more appropriately. The bulletin also outlines strategies for improving P-use efficiency. Strategies for improving the efficiency of use of soil and fertilizer P include: (i) modifying surface soil properties; (ii) managing surface soil; (iii) managing P sources; and (iv) optimizing P use through economically appropriate rates and timing. The main conclusion of this bulletin is that the efficiency of fertilizer P use is often high when evaluated over an adequate time scale using the balance method.