Lime fighting agains iron in soil?

[LAMBS-BREAD]

Hey all

Yesterday i went to a farming cooperative to get some zeolite and lime and some iron, this old man explain to me that lime was blocking the iron in the soil so the plant cant use it from there, he said i should add Fe in the water i use to water the plant...

Anyone know bout this?

 

[VerdantGreen]

iron availability starts to go down above pH 6, so your man is kind of right.
BUT
i think the best way to go is to use your powdered dolomite lime in the soil, and then amend the pH of your watering water to 5.5-6. then after you water the dolomite will slowly neutralise it to 7
this then gives a sweep of pH between 6 and 7 - at some point inbetween which most of the required minerals will be at their optimum availability to the plant.

hope that makes sense
V.

 

[LAMBS-BREAD]

good looking VG

ok i see ur point, water with a lil lower ph value so that the plante can absorb the iron then the lime will re-up the ph...i'm wondering how fast can the iron be absorb? and how can we see iron deficiency? any sign?

 

[VerdantGreen]

check out the chart here LB
http://icmag.com/ic/showthread.php?p=2372407#post2372407

iron deficiancy shows as yellowing of the leaves whilst the veins stay green
the yellowing starts on the smaller leaves at the opposite end from the tips.

but i wouldnt get hung up on iron - there are many more important minerals that get deficient much more regularly

if you are worried about iron deficiency then reduce the pH to 5ish somethimes to water and dont keep the soil too wet. - and remember Burn1's mantra - 2 tbs powdered dolomite lime per gallon of soil.

 

[Blue Dot]

Just use iron EDDHA, it is pH independant.

The chelate allows it to be taken up at above pH 6.0 and well beyond, unlike Fe DPTA, Fe Sulfate, etc.

ALL metal micronutes have a tough time being absorbed at pH 7.0.

 

[LAMBS-BREAD]

Thanks fellaz.

 

[JackTheGrower]

How much iron does Cannabis need? I sort of have thought high iron ( like volcanic soil of California ) is the best to grow in..

Just thought to ask after reading this thread.

Jack

 

[Blue Dot]

How much iron does Cannabis need? I sort of have thought high iron ( like volcanic soil of California ) is the best to grow in..

Just thought to ask after reading this thread.

Jack

Not much, it is a micronute afterall, not a macronute.

I thought volcanic soil (at least the kind from hawaii anyway) was high in manganese, not necessarily iron.

Iron is pH dependant AND oxygen dependant.

Think of this when you think iron: Acid loving plants are really iron loving plants and vice versa.

Also, iron cannot be taken up when there is low O2 in the rootzone due to overwatering.

 

[VerdantGreen]

nice post BD!

just for completeness, from cervantes grow bible,

excessive amounts of copper zinc or manganese can inhibit iron uptake, as can higher levels of phosphorous.

 

[JackTheGrower]

Not much, it is a micronute afterall, not a macronute.

I thought volcanic soil (at least the kind from hawaii anyway) was high in manganese, not necessarily iron.

You may be right.. I tried to get an answer but it's little info or extensive soil surveys I don't understand yet.

We have Red soil all over N California and I do believe it is from volcanic activity. I assumed the red is iron.

Gold, Diamonds and other stuff plus that red soil...