If clay holds cations why don't we add a little to our soilless mixes?

[Growdo Baggins]

I know clay clumps up and is sticky, but picture breaking a nice dry clump into dust and mixing a few handfuls into your bed. Would it just be unnecessary because of all the organic matter that can basically do the same thing that clay does but better?

Thanks for obliging me with all silly questions guys.

 

[Creeperpark]

I have done a few experiments using different types of clay to boost the Cation Exchange Capacity in soil-less mixes. The results were overwhelmingly of that equal to DWC plants. I could see results that appeared to be at a 400% boost when it came to the plant's need for fertilizers.

There are two ways to apply the clay to the soil-less mix. One is to add the clay to a core and insert the core into the soil-less. Using this method I feed water around the core.

The other is to add the super fine-screened clay directly to the soil-less substrate. Either way, the clay has to be super dry and extra fine to attach to the peat equally. It just takes a handful per bale of Pro-mix. IF you can tumble the mix its better in a cement mixer. You can look at my old photos in my media and see where I'm mixing up some to get an idea...

 

[troutman]

Natural soils in many places have clay mixed in. Just don't add to much if you use some.
If you add a little clay into a bucket of water and mix away it will create mud water. I've
used that a few times in the past.

 

[jackspratt61]

I have done a few experiments using different types of clay to boost the Cation Exchange Capacity in soil-less mixes. The results were overwhelmingly of that equal to DWC plants. I could see results that appeared to be at a 400% boost when it came to the plant's need for fertilizers.

There are two ways to apply the clay to the soil-less mix. One is to add the clay to a core and insert the core into the soil-less. Using this method I feed water around the core.

The other is to add the super fine-screened clay directly to the soil-less substrate. Either way, the clay has to be super dry and extra fine to attach to the peat equally. It just takes a handful per bale of Pro-mix. IF you can tumble the mix its better in a cement mixer. You can look at my old photos in my media and see where I'm mixing up some to get an idea...

What types of clays have you tried?

 

[Creeperpark]

I used many different clays from different areas. The best was black gumbo clay that's alkaline. The trick is to Sun dry the clay for a couple of weeks and then pound it into a fine super dry dust. I like to sift the clay thru a cotton t-shirt to get all the clay particles the same size before I add it to the mix. Here the plants only used 130 to 160 ppm of fertilizer using an organic core with clay.

 

[Creeperpark]

Here's a grow using clay in the whole mix and with an organic core at different stages of growth. The amount of fertilizer used was in the 160 ppm range with every watering counting calmag.

 

[jackspratt61]

Here's a grow using clay in the whole mix and with an organic core at different stages of growth. The amount of fertilizer used was in the 160 ppm range with every watering counting calmag.

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What is the organic core consist of? Compost etc?

 

[Growdo Baggins]

I have done a few experiments using different types of clay to boost the Cation Exchange Capacity in soil-less mixes. The results were overwhelmingly of that equal to DWC plants. I could see results that appeared to be at a 400% boost when it came to the plant's need for fertilizers.

There are two ways to apply the clay to the soil-less mix. One is to add the clay to a core and insert the core into the soil-less. Using this method I feed water around the core.

The other is to add the super fine-screened clay directly to the soil-less substrate. Either way, the clay has to be super dry and extra fine to attach to the peat equally. It just takes a handful per bale of Pro-mix. IF you can tumble the mix its better in a cement mixer. You can look at my old photos in my media and see where I'm mixing up some to get an idea...

Fuck yeah dude. Do you mind explaining a bit more about the core technique? I googled, trying to look into it, and I learned about this core gardening technique where you have compost or straw as the core to your garden and then soil above that. Like a hugelkultur, it sounds like. I'm picturing a bed of soil with an egg shaped ballof clay in the middle. I like the idea of spreading the fine powdered clay around, and would most likely go that route. But I was curious about the core thing.

Thank you for replying

 

[flylowgethigh]

I am working the clay issue from both ends. Outside I have clay that is too thick and needs organic material blended in. I am decomposing tree tops in a big pile to add to the clay dirt I have outside. My garden got a lot of the composted material, and will get more, to be mixed in deeper. Organic material really helps break down the wet gooey clay. It takes a lot.

Inside in my soil in the tent I wonder how adding clay fines would help as I m not sure what the cation is in the soilless mix. But the bags are about as heavy as I can stand already, and clay will make them heavier.

 

[Creeperpark]

What is the organic core consist of? Compost etc?

I use one of 3 different choices. Happy Frog or Roots Organic or Ocean Forest is used for the core. Roots Organic is my fav but they all work very well. Here are the ingredients of each mix.

Ocean Forest is aged forest products, sphagnum peat moss, earthworm castings, bat guano, fish emulsion, and crab meal. Aged forest products, sandy loam, and sphagnum peat.

Roots Organic is Perlite, coco fiber, peat moss, composted forest material, pumice, worm castings, bat guano, soybean meal, alfalfa meal, fishbone meal, kelp meal, greensand, mycorrhizal fungi.

Happy Frog is Composted forest humus, sphagnum peat moss, perlite, earthworm castings, bat guano, humic acid (derived from Leonardite), oyster shell and dolomite lime (for pH adjustment).

 

[Creeperpark]

Fuck yeah dude. Do you mind explaining a bit more about the core technique? I googled, trying to look into it, and I learned about this core gardening technique where you have compost or straw as the core to your garden and then soil above that. Like a hugelkultur, it sounds like. I'm picturing a bed of soil with an egg shaped ballof clay in the middle. I like the idea of spreading the fine powdered clay around, and would most likely go that route. But I was curious about the core thing.

Thank you for replying

Its important to match the right ground soil with the clay. Most clay is alkaline and when added to an "acidic media" it will boost the CEC. However, if you have alkaline soil and add clay it will not work.

If you have alkaline soil that is clay based you have to go the other way which is to add the "acidic peat moss" to the clay soil to boost the CEC. The best peat moss to use is Canadian peat moss with a 4 ph or lower. .

 

[Creeperpark]

I am working the clay issue from both ends. Outside I have clay that is too thick and needs organic material blended in. I am decomposing tree tops in a big pile to add to the clay dirt I have outside. My garden got a lot of the composted material, and will get more, to be mixed in deeper. Organic material really helps break down the wet gooey clay. It takes a lot.

Inside in my soil in the tent I wonder how adding clay fines would help as I m not sure what the cation is in the soilless mix. But the bags are about as heavy as I can stand already, and clay will make them heavier.

Outdoor alkaline clay soils should be amended with Canadian peat moss. The peat moss will only last about 6 months and so timing is important. I added the peat outdoors in early spring before putting out my plants.

As for adding clay to the soil mix, remember it only takes a hand full of clay for five 5-gallon pots. It has to be extra dry and ground fine and sifted into the mix evenly.

 

[Creeperpark]

Which clay type has the maximum CEC?

Bentonite and montmorillonite clay has the highest capacity potential.

Clay has a great capacity to attract and hold cations because of its chemical structure. However, CEC varies according to the type of clay. It is highest in montmorillonite clay, found in chocolate soils and black puggy alluvials.

Alluvial soils are soils deposited by surface water. You'll find them along rivers, in floodplains and deltas (like the Mississippi Delta), stream terraces, and areas called alluvial fans. This last category results from larger floods, causing the soil to spread out in the shape of a triangle fan.

I couldn't see much difference between the above and homemade black gumbo clay. The main difference was clay purity, the Bentonite and Montmorillonite are very clean and the homemade Gumbo is a little dirty. Remember it only takes a little, maybe a handful full for six 3-gallon or six 5-gallon pots.

 

[Creeperpark]

Reviewing the Cation numbers below you can see why there's no need for excess fertilizer when the substrate CEC is high. The lower the CEC the higher the concentration of nutrients needed for plant growth. Using the last 4 ingredients in the soil core inserted in a soil-less mix can boost the exchange 200% to 400%!

Cation Exchange---CEC, cmol(+) /kg*
Rockwool 0-0
perlite 0-3
kaolinite clay 3-15
illite clay 20-40
coco coir 30-40
montmorillonite clay 60-100
sphagnum peat 100-120
vermiculite 150+
soil organic matter humus, etc. 100-300

These plants are getting only 160 ppm or 0.3 EC of 3 pt GH fertilizer every 3 days..

This is an old post I saved in case the topic came up again.

 

[exploziv]

What about acidic clay, is it good to use? I used to add some to my soil mixes for CEC and micronutrients. Didn't find many info or studies on this, tho.

 

[Ca++]

Soil samples taken within a single clay valley, surprised me with the wide range of test results seen. The nutritional input from each, was very different. Though needed unlocking to some extent.

If you added a lot to your compost, you will of made soil. We are talking of a little, which instead, will be composted. It's going to act as an amendment if well mixed in, and an amendment that's difficult to judge.

I will paint it as I see it. Adding stuff to a bag of decent compost, isn't helping. If we can make it better, than it's not the decent product we wanted. If it weighs nothing, then increasing it's cec with clay is not good soil building, if you don't know what it is. If the compost is heavy, then the cec is fine, and it's probably fine to use. Needing no amendment. Especially one that's unknown.

If your home made compost was something like peat, needing air, then expanded clay might have it's uses. The balls used in hydro are not going to mush. Though they are very light, so volumetrically offer a reduction in cec. Despite being quite good per gram. Which is how we measure cec.


Some quite encyclopedic knowledge and good application there Creeperpark.

 

[Growdo Baggins]

I am working the clay issue from both ends. Outside I have clay that is too thick and needs organic material blended in. I am decomposing tree tops in a big pile to add to the clay dirt I have outside. My garden got a lot of the composted material, and will get more, to be mixed in deeper. Organic material really helps break down the wet gooey clay. It takes a lot.

Inside in my soil in the tent I wonder how adding clay fines would help as I m not sure what the cation is in the soilless mix. But the bags are about as heavy as I can stand already, and clay will make them heavier.

I'm working with heavy clay outside too and working in organic material as Icanget it. I'm just now starting this garden. We bought the house last year. I've got a bunch of compost piles and a couple pretty large leaf piles going, but other than the one compost pile I started last year, none of is ready. The leaves will be 2 years before they're broken down. I did find some really dark rich soil loaded with worms and other insects on my neighbors horse farm, but getting it over to my house isn't super easy, so it's a slow process of building more garden area for me.

 

[flylowgethigh]

Soil samples taken within a single clay valley, surprised me with the wide range of test results seen. The nutritional input from each, was very different. Though needed unlocking to some extent.

If you added a lot to your compost, you will of made soil. We are talking of a little, which instead, will be composted. It's going to act as an amendment if well mixed in, and an amendment that's difficult to judge.

I will paint it as I see it. Adding stuff to a bag of decent compost, isn't helping. If we can make it better, than it's not the decent product we wanted. If it weighs nothing, then increasing it's cec with clay is not good soil building, if you don't know what it is. If the compost is heavy, then the cec is fine, and it's probably fine to use. Needing no amendment. Especially one that's unknown.

If your home made compost was something like peat, needing air, then expanded clay might have it's uses. The balls used in hydro are not going to mush. Though they are very light, so volumetrically offer a reduction in cec. Despite being quite good per gram. Which is how we measure cec.


Some quite encyclopedic knowledge and good application there Creeperpark.

On my property I have red clay, yellow clay, and gray gumbo clay. Plus this white stuff that is solidified something with shells in it. The red clay is the good stuff, but needs a bunch of humis. And lime. I suspect the positive calcium ions are attaching to the clay and helping break the electrical bonds between clay particles, but no idea really. I had to use a lot of the yellow stuff as topsoil to level a spot, and it needs a lot of help.

When they say forest material, they mean tree trimmings. Any kind of trees. I tell the wood chip guy only hardwoods no pine. Pine is acidic also.

 

[Ca++]

My efforts to loosen up clay with compost have been dire. It seems that to fix up 1Kg of clay, needs perhaps 1Kg of compost. However, clay must have 3 times the SG and I would like to see the top 6" come good. So, maybe, I need 18" of compost. Which is unrealistic to walk a mile with.
I have filled 10L holes with 50/50 mix, and a couple of seasons later the clay has taken in. Somehow liquefied over the winters. Run through the compost, and dropped in the hole a long way. Which is where the 3:1 ratio idea is coming from. Years on, having turned these holes again, adding more compost, I really need to reevaluate that ratio again. As it's really not happening. Though the ground is changing colour, it is still clay.

Edit: It's all red in my valley, though that white stuff is down there, like a seam I shouldn't ever reach. Though I can if I dig too deep

 

[flylowgethigh]

I'm working with heavy clay outside too and working in organic material as Icanget it. I'm just now starting this garden. We bought the house last year. I've got a bunch of compost piles and a couple pretty large leaf piles going, but other than the one compost pile I started last year, none of is ready. The leaves will be 2 years before they're broken down. I did find some really dark rich soil loaded with worms and other insects on my neighbors horse farm, but getting it over to my house isn't super easy, so it's a slow process of building more garden area for me.

Watch out for horse manure if they spray 'graze-on' to kill weeds in the pasture. The stuff is edible Round-up, and will pass through the animals guts and still kill plants.