Interaction among Fertilizers (Compatibility)

When preparing fertilizer solutions for nutrigation , each component solubility must be considered in order to avoid possible precipitate .

The following mixtures reduce solubility and form the following sedimentations. 
• Calcium nitrate with sulfates = formation of CaSO4 precipitates ( gypsum). 
Ca(NO3)2 +(NH4)2SO4 → CaSO4 
• Calcium nitrate with phosphates = precipitation and formation of Ca phosphate. 
Ca(NO3)2 +NH4H2PO4 → CaHPO4 
• Magnesium with di or mono ammonium phosphate =precipitation of Mg phosphate. 
Mg(NO3)2 + NH4H2PO4 → MgHPO4 
• Ammonium sulfate with KCl or KNO3 = formation of K2SO4 
(NH4)2SO4+KCl or KNO3 → K2SO4 
• Phosphorus with Iron = formation of iron phosphate. 



• In hard water ( Ca > 60 ppm , Mg > 30 ppm and bicarbonate HCO3 > 150 ppm ) = formation of Ca carbonates due to high pH without using acids in order to eliminate HCO3. 
CO32- +Ca2+ → CaCO3 .( in the photo a typical CaCO3 precipitate can be seen - Rivera Chapala - Jalisco - Mexico . ) 


Oded Rottenberg 
Haifa Mexico