Field evaluation of pelletised calcined and insoluble residue of Christmas Island ‘C’ phosphates

Abstract Two pelletised fertilisers, calcined and the alkali insoluble residues of Christmas Island ‘C’ phosphate (CICP), were compared with powdered materials in a pasture mowing trial. The pelletising process used 10% non-swelling New Zealand bentonite clay to bind the ground materials. The pelletised materials performed well under field conditions. Over 2 years the general trend was for pelletised materials to produce slightly more pasture and to raise Olsen P soil levels compared with the corresponding powdered products.