Colloidal-Bound Polyphosphates and Organic Phosphates Are Bioavailable: A Nutrient Solution Study.

Colloidal forms of Fe(III) minerals can be stabilized in solution by coatings of organic or poly-phosphate (P), which reduce the zeta-potential. This opens up a route toward the development of nanoforms of P fertilizers. However, it is unclear if such P forms are bioavailable.