INFLUENCE OF CONIFERS ON THE FORMS OF PHOSPHORUS IN SELECTED NEW-ZEALAND GRASSLAND SOILS

We examined the effects of conifers on the forms of P in low-fertility tussock grassland soils using P-31 nuclear magnetic resonance (NMR) a nd soil P fractionation, Results from field and glasshouse experiments clearly demonstrated that conifers enhanced the mineralization of lab ile (and to a lesser extent more resistant) forms of soil organic P wh ich, in turn, increased amounts of labile inorganic P in the soil. The se findings have important implications for P availability and long-te rm sustainable management of grassland soils in New Zealand.