terra cotta

[Beetleman72]

Would using a terra cottage pot increase overall CEC of a soil?

 

[GrimLore]

I am no pro on the subject but it is my understanding that CEC values in soil from its' clay content is far different then a "fired" pot. To better explain that pot is "cooked" and I doubt there is any nutritional value left...

 

[Dav4]

Would using a terra cottage pot increase overall CEC of a soil?

The Cation Exchange Capacity of your soil, as a whole, depends mainly on the CEC of its components. There've been a few threads on the subject, but if I remember correctly: organic materials have a relatively high CEC, clay aggregates like akadama or turface have a moderate CEC, and sand/grit/lava have relatively low CEC. A clay container, like terra cotta, might have a moderate (?) CEC, but I doubt it will effect that of the soil (except if you crush it up and mix it with your soil).

 

[Stan Kengai]

Ever notice salt build up on terracotta or potting medium (lava and pine bark specifically). That's proof that those substances have (at least to some extent) properties that promote cation exchange.

 

[nathanbs]

Ever notice salt build up on terracotta or potting medium (lava and pine bark specifically). That's proof that those substances have (at least to some extent) properties that promote cation exchange.

this is a little over my head so I wont argue, but does this mean my cotton t-shirts have properties that promote CEC as they show sweat/salt stains in the summer?

 

[Oliver Muscio]

Stan, I think I would have to disagree with you here. The salt stains are due to the medium (terracotta, etc) absorbing the salt solution, with the water evaporating and leaving the (calcium, mostly) salts behind on the surface. That's wicking, not cation exchange.
Oliver Muscio

 

[Stan Kengai]

Why is it that when someone tries to simplify a concept, the naysayers come out of the woodwork?

Terracotta, just like the clay it is made of, has the ability to attract and hold cations. To what degree, I'm not sure; obviously less than raw clay, and probably slightly less than Turface or hard akadama. Since the board is in a "show me your qualifications" mood, would you like me to post my college transcript or are pics of my 5 college chemistry books sufficient?

 

[nathanbs]

dont get your panties in your a bunch its not simplifying a concept its misleading the OP in his question. It is what it as Grimlore said once anything is high fired all cation exchance capacity is lost. I was trying to be polite in contradicting you but apparently that didnt work. Why not just be wrong its an enlightening experience. Try it.

 

[Stan Kengai]

dont get your panties in your a bunch its not simplifying a concept its misleading the OP in his question. It is what it as Grimlore said once anything is high fired all cation exchance capacity is lost. I was trying to be polite in contradicting you but apparently that didnt work. Why not just be wrong its an enlightening experience. Try it.

If you don't have anything to actually contribute to the conversation (other than your need for antiperspirant), why are you even responding? Explain why I'm wrong scientifically, and I'll "be wrong".

 

[nathanbs]

I am no pro on the subject but it is my understanding that CEC values in soil from its' clay content is far different then a "fired" pot. To better explain that pot is "cooked" and I doubt there is any nutritional value left...

Stan, I think I would have to disagree with you here. The salt stains are due to the medium (terracotta, etc) absorbing the salt solution, with the water evaporating and leaving the (calcium, mostly) salts behind on the surface. That's wicking, not cation exchange.
Oliver Muscio

dont get your panties in your a bunch its not simplifying a concept its misleading the OP in his question. It is what it as Grimlore said once anything is high fired all cation exchance capacity is lost. I was trying to be polite in contradicting you but apparently that didnt work. Why not just be wrong its an enlightening experience. Try it.

Sorry but i did contribute and so did these others. You are wrong scientifically because anything that is high fired becomes inert and has 0 CEC.

 

[Smoke]

CEC has to do with the organics not the clay. The clay is just a vessel for the exchange to take place. The CEC becomes higher do to increased organics. Take away the organics and clay becomes as useless as sand.

The organics are in most clay via decomposition...or... can be introduced via, organic fertlizer (which takes time to be useful) or the direct use of humates ( humic acid) which are (immediatly usable). A fired clay pot could have its CEC improved via humic acid as well as pumice and lava. I use clay pots a lot. I don't use them for the CEC ability, I just like them because they breath and afford air exchange, something a figh fired bonsai pot can not do.

Think of the "C" in CEC. A cation...or cat-ion as an electricallycharged particle. Thats ca-tee-on not cashin. A fertlizer ion also has an electrical charge. What the CEC does, is measure the exchange of polarity of the two to make them attract rather than repel. So one is a cat-ion and the other an-ion or anion. an-ee-on

 

[edprocoat]

Well, this has certainly been an edu-cation !

ed

 

[markyscott]

Carbon and organics burn off at fairly low temperatures during firing (300-800 C). I'd imagine that would significantly lower the CEC of the remaining clay, but clays have charged surfaces so they have a higher CEC than quartz. As the clay is sintered at higher temperatures, the clay breaks vow - I'd imagine that would drop the CEC further.

There have been a number of threads discussing how to raise the CEC of soil. The answer is easy - add some organics. But implicit in these discussions is the assumption that having a high CEC soil is a good or desirable goal. I wonder - is it helpful for plants in bonsai culture to grow in a medium that binds fertilizer?

Scott

 

[GrimLore]

But implicit in these discussions is the assumption that having a high CEC soil is a good or desirable goal. I wonder - is it helpful for plants in bonsai culture to grow in a medium that binds fertilizer?

Scott

The only applications(s) I see so far that are Bonsai related concerning CEC in my opinion is when you are planting a plant on a rock or similar. John G mixes potting clay, sphagnum, and peat when attaching a plant to a stone and it creates the medium needed to retain water and promote growth. Otherwise those plantings would require constant water

I appreciate everyone's input but I will continue in my thinking that my clay pots are inorganic after being "fired" and do not effect the CEC activity in substrate.

It has given me an idea actually being I prefer inorganic medium which I will try with a few plants in the Spring.

 

[Dave Leppo]

Refreshing to get to the actual answer here for me as well, as I use crushed brick exclusively as a substrate, and I expect it to act similar to a clay pot in CE exchange, (none).

 

[Poink88]

This article may help a bit.
http://www.extension.purdue.edu/extmedia/ay/ay-238.html

 

[markyscott]

Thanks Dario. A nice summary and one I've seen before. I understand the the science and can clearly see why someone growing in a nursery container or in the ground might be concerned. But why in bonsai culture? Why not simply use a lower CEC substrate and fertilize more frequently?

Scott

 

[Poink88]

Thanks Dario. A nice summary and one I've seen before. I understand the the science and can clearly see why someone growing in a nursery container or in the ground might be concerned. But why in bonsai culture? Why not simply use a lower CEC substrate and fertilize more frequently?

Scott

It sure will work that way too but I think it is very important to understand this, before someone who uses a high CEC mix (like me for example because I need high water retention) start using Walter Palls fertilizing regimen.

Or the other way around where someone uses a low CEC mix and not fertilize enough.

 

[GrimLore]

Thanks Dario. A nice summary and one I've seen before. I understand the the science and can clearly see why someone growing in a nursery container or in the ground might be concerned. But why in bonsai culture? Why not simply use a lower CEC substrate and fertilize more frequently?

Scott

I have slowly switched most of my trees to total inorganic this year and will do the balance in Spring before they wake up. My reason is everything does fine without organic and I have the time to water and fertilize. Also in late Spring I will be going to automated watering which will give me a lot more time to get and work on good stock. Most people that choose to have certain amounts of organic do so because of the time it takes to water and fertilize, As Dario says it depends on climate, time, diligence, and realistic approach.

 

[ABCarve]

I have slowly switched most of my trees to total inorganic this year and will do the balance in Spring before they wake up. My reason is everything does fine without organic and I have the time to water and fertilize. Also in late Spring I will be going to automated watering which will give me a lot more time to get and work on good stock. Most people that choose to have certain amounts of organic do so because of the time it takes to water and fertilize, As Dario says it depends on climate, time, diligence, and realistic approach.

Which watering system are you going with? I'm looking now myself.