Phosphorus Availability to Corn as Affected by Granulating Manganese with Ortho- and Pyrophosphate Fertilizers1
- P. M. Giordano and
- J. J. Mortvedt2
The presence of MnSO4 at a level of 10% Mn in granular ammonium polyphosphate (APP) and triammonium pyrophosphate (TPP) significantly reduced corn (Zea mays L.) forage yields and P uptake relative to treatments where P and Mn were applied separately in greenhouse pots. A significant reduction in P uptake resulted when MnSO4 was combined with monoammonium phosphate (MAP), but no yield reduction occurred.
Chemical extraction of the fertilizers indicated that the solubilities of both P and Mn were reduced when MnSO4 was granulated with APP or TPP. A compound of very low solubility, Mn(NH4)2P2O7 · 2H2O, was identified as the principal reaction product. Accordingly, movement of P in soil was restricted to a greater extent when MnSO4 was combined with TPP than with MAP.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © .