B) Percentage dissolution of NCPR and SPR was very similar in all 18 soils (Fig.
The percentage NCPR dissolution values obtained from this study were similar to those obtained for the NCPR with the same 18 soils by Hughes and Gilkes (1994).
Hughes and Gilkes (1994) indicated that titratable acidity had a major influence on NCPR dissolution in 228 WA soils.
Soil properties that are most closely related to percentage PR dissolution Untransformed data NCPR SPR Property [r.
SSP was much more effective for production of yield than NCPR and SPR for soil 2, soil 5, and soil 14 (Fig.
SSP was more effective for producing plant yield than either NCPR or SPR for all 18 soils.
Previous studies have also shown that NCPR and SPR are about equally effective for producing plant yield (Fenster and Leon 1979; Hammond 1979; Mackay et al.
Previous research in WA has shown that NCPR is poorly effective compared with SSP, both in the year of application and in the years after (Bolland et al.