Ferrous sulfate question

Robert robert at tomgrower.demon.co.uk
Sun Apr 16 15:31:37 EST 2000


In article <x0w5wTALJV+4EwcS at upthorpe.demon.co.uk>, Oz
<Oz at upthorpe.demon.co.uk> writes
>
>>Iron shortage is a chronic problem due to  the winter rainfalls of the Pacific
>>Northwest.
>
>That's interesting. Here it's high pH lockup. 
>I rather assumed your soils were acid but the water pH suggests
>otherwise.
>

Growing tomatoes hydroponically we use a chelated form of iron, FeEDTA,
and the last 4 years several other trace elements in chelated form.
FeEDTA starts to drop out of solution above about pH 6.5. There are
other forms of chelated iron which remain available at higher pH's but
much more expensive.

When we first stated using hydroponics we used ferrous sulphate, but
even at a computer controlled pH of 5.8, it drops out of solution
leaving a nasty deposit on the roots which was generally felt to be
damaging or at least inhibitory. 
-- 
Robert 

Fundamentalist opposed to witchcraft




More information about the Ag-forst mailing list