The Buzz On Biochar In Peat-Moss Based Media Mixes

[pjlive]

I'm going to be jumping on the biochar bandwagon starting on my next grows. I'm hoping to be able to enhance the microbial activity in my media mix. In theory, at optimal ratio proportions, this will not only aid with overall growth and moisture retention (now that vermiculite is definitely out with me), but has a chance to noticeably enhance scent and taste profiles for cannabis grown in a soil-less hydroponic media. I'm interested in discovering if the current biochar for cannabis claims are worthy.

Some general information can be gleaned from a study on the use of biochar in combination with peat moss based media: Effects of Biochar Mixes with Peat-moss Based Substrates on Growth and Development of Horticultural Crops.

 

[BOMBAYCAT]

If you have any questions about Biochar, Silver Surfer had quite a primer about Terra Prieta (biochar) several years back. I use Biochar and pumice used for cactus soil and it gives the Myco a place to live. The formerly rust red Pumice gets all black from the biochar so I assume the Myco is dragging it in?

 

[pjlive]

If you have any questions about Biochar, Silver Surfer had quite a primer about Terra Prieta (biochar) several years back. I use Biochar and pumice used for cactus soil and it gives the Myco a place to live. The formerly rust red Pumice gets all black from the biochar so I assume the Myco is dragging it in?

Thanks @BOMBAYCAT. If you're willing to answer, are you using your biochar pre-innoculated? Are you using it blended in to your media mix or setting it up in layers -- or both?

I'm still getting ready, thinking about it, and trying to figure out a good starting percentage per square foot of media.

 

[BOMBAYCAT]

I use it pre-charged. My mentor didn't pre-charge once and the grow turned a lovely shade of yellow. LOL

 

[BOMBAYCAT]

I mix up Biochar into the media when I am building or amending soil less. I think Silver Surfer recommended about 12% by volume mixed into media. If I add too much, it gets spilled and tracked all over and it is a mess because it is so black like charcoal.

 

[little-soldier]

Looking into trying a plant or two with biochar also. I will probably do one in coco and one in promix.Whatdo you mean pre-charge and how would i go about pre-charging it Bombaycat?

 

[pjlive]

Looking into trying a plant or two with biochar also. I will probably do one in coco and one in promix.Whatdo you mean pre-charge and how would i go about pre-charging it Bombaycat?

You can precharge your char by soaking it in water that contains any micro or fungus organisms. The char will absorb the water and house active life while in the pot. If you don't soak prior, you risk allowing the biochar to absorb all the nitrogen it can and keep it from the plant's roots. It's a tricky pot element to use, but some are getting great results, I guess...

 

[pjlive]

I mix up Biochar into the media when I am building or amending soil less. I think Silver Surfer recommended about 12% by volume mixed into media. If I add too much, it gets spilled and tracked all over and it is a mess because it is so black like charcoal.

Thanks very much for all your feedback! Yes, it's tricky stuff. I think I might start somewhere between 8-10% in a single layer about 2/3 down the pot. I don't know for sure yet. I'm definitely going to be soaking and pre-innoculating.

 

[xet]

I'm going to be jumping on the biochar bandwagon starting on my next grows. I'm hoping to be able to enhance the microbial activity in my media mix. In theory, at optimal ratio proportions, this will not only aid with overall growth and moisture retention (now that vermiculite is definitely out with me), but has a chance to noticeably enhance scent and taste profiles for cannabis grown in a soil-less hydroponic media. I'm interested in discovering if the current biochar for cannabis claims are worthy.

Some general information can be gleaned from a study on the use of biochar in combination with peat moss based media: Effects of Biochar Mixes with Peat-moss Based Substrates on Growth and Development of Horticultural Crops.

I powder my char and then brew it into an actively aerated compost tea.

 

[pjlive]

I powder my char and then brew it into an actively aerated compost tea.

Hi there, xet, and thanks for your input. I've read about a few others from elsewhere online that use the powder and soak biochar method for their cannabis plants with good success. I'm still not sure how I'm going to go about it, or even if I'll be going about it at all. But I'm definitely interested.

Thanks again. I'll use all the info I can glean to make the best choices on the process if I do end up taking the plunge. I might even run a side-by-side, one mixed, one layered, to see what's what.

 

[little-soldier]

Sounds like a hassle to presoak stuff. What’s the difference between biochar and hydroton/lava rock. Don’t they both do the same?

 

[Cerathule]

Biochar has a higher CEC but needs to be saturated with nitrogen or it will fix that, which will stunt microbial life. Substrates for healthy plants need a C:N ratio of 20:1-10:1, but unbuffered biochar adds mostly C.
It's also quite hydrophobic but can be really helpful to buffer nutes and boost microbial life via its high porosity

 

[goingrey]

Biochar has a higher CEC but needs to be saturated with nitrogen or it will fix that, which will stunt microbial life. Substrates for healthy plants need a C:N ratio of 20:1-10:1, but unbuffered biochar adds mostly C.
It's also quite hydrophobic but can be really helpful to buffer nutes and boost microbial life via its high porosity

Isn't it supposed to retain water?

Ok I see it depends on what kind of wood was used and how it was burned.

https://www.sciencedirect.com/science/article/abs/pii/S0961953413005230

So make sure you get the right kind or make it right yourself.

What's interesting is that I've seen it advertised as a soilless media by itself. I wonder how that would work.

 

[pjlive]

Sounds like a hassle to presoak stuff. What’s the difference between biochar and hydroton/lava rock. Don’t they both do the same?

I used to use lava rock for a while, but unfortunately I had some issues where roots would get damaged on the jagged edges. Biochar is said to house all sorts of favorable microorganisms beneficial to cannabis. You can even pick which organisms to populate your char. I agree it does seem like a hassle. But I'm considering its use because of some articles and blurbs I read about it being able to enhance the taste and scents in a soilless media to help bring things a little closer to a soil based grow. Even if it's true it's unlikely to equal the power of soil in that respect, but I like the thought of getting a little closer to it.

 

[pjlive]

What's interesting is that I've seen it advertised as a soilless media by itself. I wonder how that would work.

I've been wondering this same thing. My first guess it that it would fail miserably because the plant would be too deprived of Nitrogen. But I have seen those claims myself. I find it very hard to believe.

 

[goingrey]

I've been wondering this same thing. My first guess it that it would fail miserably because the plant would be too deprived of Nitrogen. But I have seen those claims myself. I find it very hard to believe.

Maybe the idea is to keep it saturated with a heavy feed? Very hard to find info growing in straight biochar online. Some people do claim to have done it though.

 

[Cerathule]

Maybe the idea is to keep it saturated with a heavy feed?

Ecactly this. Use urea, then cook for a few days, problem solved.
Usually biochar for horti comes preped already.

Isn't it supposed to retain water?

To a certain extent, yes. But in comparison to blackpeat, only half of that. Still not bad, I like an airy medium. But a surfectant like Yucca may come in handy then as well

 

[clearheaded]

i think the only REAL reason it was used to begin with and then adapted, was for breaking new ground, building an airy soil quickly, adding potash etc with added benefit of "sequestering carbon" i could be wrong, and would love to see some side by sides of a mix with perlite and with perlite plus biochar. this spending 50$ for a bag that has been shipped from 1000km away is silly, and not what the concept was developed for. is dark carbon rich soil good? yup.. but little hype me thinks.. ive been wrong before!

 

[goingrey]

Usually biochar for horti comes preped already.

The one I bought for my outdoor mix (veggies) this year was not. But they do say that on the package, that it must either be pre-charged before use or mixed with compost. I did the latter, mixed it in without pre-charging to my mix that two types of compost (one peat-based with added plant compost, one bark based with added chicken and horse manure, mycorrhiza), used coco, LECA, bonemeal, worm castings.. Plants have never been happier but the weather has been exceptionally good as well so not sure how much can be attributed to the biochar. Anyway, doesn't seem to have hurt.

They say this biochar is made entirely from spruce at 600c (1112f).

 

[pjlive]

Maybe the idea is to keep it saturated with a heavy feed? Very hard to find info growing in straight biochar online. Some people do claim to have done it though.

As far as I can figure on my own, yes. Now I'm thinking that if I do use it and inoculate it properly I'll have to set it much higher up in the pot. Maybe somewhere between 5 and 10 percent from the top. That region will have to be kept consistently moist so I don't kill off the goodies with a dryback.

I don't know if I'm actually going to do this, goingrey. The more I dig, the more concerns I have.