Re: Iron oxidation states

Dr. Dave wrote:

> Chelation is the only way to deliver adequate 
> amounts of iron to plants via the water column. BTW EDTA complexes iron 
> as the Ferric (+3) ion.
> Biologically, the valence state of Fe makes all the difference in the 
> world ... its precisely because of its redox properties that makes Fe one 
> of the central atoms in photosynthesis and respiration.
	I take it from this that the plants _can_ absorb it as Fe(III),
and then _use_ it in whatever state is necessary.  Is this so?

Paul Sears       Ottawa, Canada