Granular reactive apatite rock phosphate is not an effective phosphorus fertilizer in the short term on lateritic soils in south-western Australia.

MDA Bolland, AJ Weatherley, RJ Gilkes and JW Bowden

Australian Journal of Experimental Agriculture 26(2) 217 - 225
Published: 1986

Abstract

The effectiveness, as a phosphate fertilizer, of granular reactive rock phosphate (carbonate substituted apatite from North Carolina, U.S.A.), granular triple superphosphate and partly powdered Duchess non-reactive rock phosphate (low carbonate apatite from north-eastern Australia) was compared in three field experiments on different soil types in different climatic regions of south-western Australia. Calciphos (finely ground calcined crandallite rock phosphate from Christmas Island) was included in one experiment. The rock phosphates were incorporated into the soil and their effectiveness was compared with both topdressed and incorporated superphosphate. Different species were grown at each site (barley, triticale and subterranean clover). As determined on the basis of relative amounts of fertilizer required for constant yield, the effectiveness of all the rock phosphates relative to incorporated superphosphate was very low at each site throughout the growth of each species. Fertilizer effectiveness of rock phosphates was about one-fifth that of superphosphate for barley, and one-tenth for triticale and clover. The maximum yield obtained from rock phosphate was generally 88-100% that obtained from superphosphate. Incorporation did not greatly affect the effectiveness of superphosphate. Keywords: Phosphorus fertilizers; rock phosphate; lateritic soils; Soil types (genetic); Ferralsols; Triticale; Barley; Hordeum; Hordeum vulgare; Western Australia; Australia; fertilizer value; fertilizers; Poaceae; Cyperales; monocotyledons; angiosperms; Spermatophyta; plants;

Full text doi:10.1071/EA9860217

© CSIRO 1986