Skip to main content

The effectiveness of recovered magnesium phosphates as fertilizers in neutral and slightly alkaline soils

Massey, M.S. and Davis, J and Ippolito, J.A. and Sheffield, R.E. (2009) The effectiveness of recovered magnesium phosphates as fertilizers in neutral and slightly alkaline soils. Agronomy Journal. 101(2):323-329.

[img] PDF

Download (725kB)


Magnesium phosphates such as struvite (MgNH4PO4x6H2O) can be recovered from municipal, industrial and agricultural wastewaters. However, minimal research has been conducted on the beneficial reuse of these recovered products; conducted research has focused on low pH soils. This study determined whether recovered struvite and dittmarite (MgNH4PO4xH2O) were effective P fertilizers in alkaline soils. In addition to commercially available triple superphosphate (TSP) and certified organic rock phosphate (RP), recovered struvite, dittmarite, and a heterogeneous recovered phosphate were evaluated in a laboratory dissolution study and as fertilizers for spring wheat (Triticum aestivum L.) in a greenhouse study. Struvite and dittmarite were much more soluble than RP, but less soluble than TSP. Laboratory dissolution kinetics were fast, with most materials nearing equilibrium within 24 hours. At a soil pH of 6.5, both dittmarite and struvite increased the average plant P concentration over the control. Struvite and dittmarite performance was similar to TSP. There were no significant differences in plant dry matter (DM) production or total P uptake at pH 6.5. In the limed soil (pH 7.6), many treatments had plant P concentrations significantly lower than the control, but most fertilizers increased DM production over the control; all fertilizers generally performed similarly to one another. These findings support previous work showing recovered Mg phosphates to be effective in acidic soils, and provide evidence that they are also effective in alkaline soils. Recovered Mg phosphates could become a useful alternative for P fertilization in arid and semi-arid environments.

Item Type: Article
NWISRL Publication Number: 1532
Subjects: Soil > Chemistry
Soil > Fertility
Soil > Soil quality
Depositing User: Dan Stieneke
Date Deposited: 17 Dec 2014 21:05
Last Modified: 17 Dec 2014 21:06
Item ID: 1576