This study has evaluated eleven precipitated phosphates as sources of phosphorus (P) or plant growth by comparing their effectiveness with that of monocalcium phosphate (MCP), a source of water-soluble P that is generally considered to be fully plant available. The precipitated phosphates comprised Struvites recovered from wastewater discharges (mainly magnesium ammonium phosphate), laboratory synthesised Struvites, a synthetic iron phosphate and a recovered calcium phosphate. The grass dry-matter yields and P offtakes given by the synthetic and recovered Struvites were not significantly different statistically either between themselves or to MCP applied at the same rate. On this basis these Struvites could be used to recycle P to similar soils and the effect of the P on crop yield should be similar to that of MCP.
JOHNSTON, A.E. ; RICHARDS, I.R. (2004): Effectiveness of Different Precipitated Phosphates as Phosphorus Sources for Plants. In: Phosphorus Research Bulletin : Volume 15 , 52-59.