Date   

Multifunctional applications of biochar beyond carbon storage

Tom Miles
 

See this excellent review article by many authors:

Multifunctional applications of biochar beyond carbon storage

Biochar is produced as a charred material with high surface area and abundant functional groups by pyrolysis, which refers to the process of thermochemical decomposition of organic material at elevated temperatures in the absence of oxygen. The carbon component in biochar is relatively stable, and, hence, biochar was originally proposed as a soil amendment to store carbon in the soil. Biochar has multifunctional values that include the use of it for the following purposes: soil amendment to improve soil health, nutrient and microbial carrier, immobilising agent for remediation of toxic metals and organic contaminants in soil and water, catalyst for industrial applications, porous material for mitigating greenhouse gas emissions and odorous compounds, and feed supplement to improve animal health and nutrient intake efficiency and, thus, productivity. This article provides for the first time an overview of the multifunctional values and unintended consequences of biochar applications.

https://www.tandfonline.com/doi/full/10.1080/09506608.2021.1922047

 

 


Re: size of biochar for various aplications ?

Ron Larson
 

List, cc Nado and Norm (I’ve known both for a long time aand impressed by both - ss for almost all before me.on this impressive and important thread.  
I acknowledge the many other thread contributors. 

1.  This coming since this is one of this list’s fastest moving and best threads ever.  Thanks to Nando for starting this - with just one cite.

2.  The 1988 Oades article is available non-fee at 

It clearly is first rate.

3.   I checked Google Scholar on number of cites in 2021.  So far (1/4 year) over 900.   Possibly heading for 3000

4.  I thought this is a wonderful tribute to biochar.  But (not counting, it seemed only maybe 1/4 or 1/5 of the papers were biochar oriented)

5.  So I checked also for. 2007 (Biochar's first official year) - and found almost 1000 Oades cites.(probably not more than one or two cites using the word “biochar"). 

So the topic is a faster growth area for biochar than other soil areas.  Both growth rates would be good to know.

6.  So I hope someone can carry this biochar literature growth question further. (And others). 
I’m going to continue working only on non-size, non-soil biochar issues - with thanks to those in those two specific biochar areas

7.  I recommend Nando’s web cite - given below.

8.  I hope someone with the Musk X-Prize group is reading thist.  This is only one of several biochar-CDR areas full of important difficult science - deserving of $100 million.

Ron



On May 7, 2021, at 3:58 PM, Nando Breiter <nando@...> wrote:

Norm,

The numbers I gave were just illustrative, as I wrote. It makes sense to me that a portion of a pore would be exposed to the circulating soil solution, and I used the research on how deep bacteria survive in char pores as a proxy of how deep the soil solution might freely circulate. You wrote "the transport of cations and anions is at the molecular level - in and out of pores and their internal surface area". My question is how free is that in and out, particularly the out.

Do char pores in soil remain open, or do they fill with debris?
Are there forces that circulate soil solution in and out of the pores? Or do the pores become filled as the char particle hydrates and circulation tends to stagnate?

To obtain nutrients bound to organic carbon and clays, plant roots will release H+ cations to the soil solution. How easily does H+ circulate into relatively deep char pores, are exchanged with nutrient cations, and those nutrient cations circulate back out of the pore to be absorbed by the plant? I'm sure it can happen. It just seems to me that the focus on the vast internal surface area of biochar pores is an exaggeration, and that cation exchange will occur much more easily on the outer, exposed surfaces of a char particle, which may include the entrance to a pore, but the deeper the pore, the less likely it seems cation exchange might occur.

There is a common theme expressed that freshly produced biochar can sorb nutrients in a way that depletes plant availability, "so make sure to charge your biochar before adding it to soil". Why would biochar in particular behave like this when clays and other types of organic carbon do not? Are nutrients in soil solution being sorbed into pores and getting trapped in there because the H+ cations plant roots release cannot reach them?

If the char particle is small enough, say 100 microns or so, H+ cations will be able to more easily circulate into the entrance of a pore, exchange with a plant nutrient cation sorbed at a negatively charged site, and that cation circulate out of the pore to be absorbed. In this case, a much greater percentage of the internal pore structure of that small particle would be easily available for cation exchange compared to one that is significantly larger.


CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 10:34 PM Norm Baker <ntbakerphd@...> wrote:
Nando;

Those exposed surface areas seem to be just the external surface area. Those make sense. But, in a soil, exposed to a water soil solution, the transport of cations and anions is at the molecular level - in and out of pores and their internal surface area. Yes, the formation of carboxyl groups on the surface of biochar is assumed to be at the surface. Does anyone agree or disagree with this statement? In other words, I find it plausible to believe carboxyl groups are formed within the whole, but probably not all, of a biochar particle.

I find it more relevant to think of biochar as existing in a soil solution exposed to all of the ions available.

Feel free to disagree.

Norm



--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


Re: IBI funding

Trevor Richards
 

Hi Kathleen,
I tried to share your funding news on both a FB page & group but FB is rejecting your news as spam...
see attached...
Screenshot 2021-05-08 10.10.50.png
seems a bit weird


On Fri, 7 May 2021 at 10:08, Kathleen Draper <biocharro2@...> wrote:
Here is the official press release about the grant!
Woka Foundation Grant to IBI Recognizes Transformative Potential of Biochar - biochar-international


Re: size of biochar for various aplications ?

Nando Breiter
 

Norm,

The numbers I gave were just illustrative, as I wrote. It makes sense to me that a portion of a pore would be exposed to the circulating soil solution, and I used the research on how deep bacteria survive in char pores as a proxy of how deep the soil solution might freely circulate. You wrote "the transport of cations and anions is at the molecular level - in and out of pores and their internal surface area". My question is how free is that in and out, particularly the out.

Do char pores in soil remain open, or do they fill with debris?
Are there forces that circulate soil solution in and out of the pores? Or do the pores become filled as the char particle hydrates and circulation tends to stagnate?

To obtain nutrients bound to organic carbon and clays, plant roots will release H+ cations to the soil solution. How easily does H+ circulate into relatively deep char pores, are exchanged with nutrient cations, and those nutrient cations circulate back out of the pore to be absorbed by the plant? I'm sure it can happen. It just seems to me that the focus on the vast internal surface area of biochar pores is an exaggeration, and that cation exchange will occur much more easily on the outer, exposed surfaces of a char particle, which may include the entrance to a pore, but the deeper the pore, the less likely it seems cation exchange might occur.

There is a common theme expressed that freshly produced biochar can sorb nutrients in a way that depletes plant availability, "so make sure to charge your biochar before adding it to soil". Why would biochar in particular behave like this when clays and other types of organic carbon do not? Are nutrients in soil solution being sorbed into pores and getting trapped in there because the H+ cations plant roots release cannot reach them?

If the char particle is small enough, say 100 microns or so, H+ cations will be able to more easily circulate into the entrance of a pore, exchange with a plant nutrient cation sorbed at a negatively charged site, and that cation circulate out of the pore to be absorbed. In this case, a much greater percentage of the internal pore structure of that small particle would be easily available for cation exchange compared to one that is significantly larger.


CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 10:34 PM Norm Baker <ntbakerphd@...> wrote:
Nando;

Those exposed surface areas seem to be just the external surface area. Those make sense. But, in a soil, exposed to a water soil solution, the transport of cations and anions is at the molecular level - in and out of pores and their internal surface area. Yes, the formation of carboxyl groups on the surface of biochar is assumed to be at the surface. Does anyone agree or disagree with this statement? In other words, I find it plausible to believe carboxyl groups are formed within the whole, but probably not all, of a biochar particle.

I find it more relevant to think of biochar as existing in a soil solution exposed to all of the ions available.

Feel free to disagree.

Norm


--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


Root penetration of biochar particles.

Joshua Bogart
 

There has been some discussion about how deep into a particule of biochar a root will penetrate. I was digging in a 3 year old pile today, this pile had been left and overgrown by wild strawberries, blackberries and goldenrod. In the pictures you can see pieces over 1/2 inch that have blackberry or golden rod root that have grown completely through them. 

While, I screen my char to be under 1/8th inch ( that is why I was digging in this pile), the sugestion I have often seen that roots might not be able to penetrate over 20 microns doesn't seem to fit this observation. 


Re: size of biochar for various aplications ?

Norm Baker
 

Nando;

Those exposed surface areas seem to be just the external surface area. Those make sense. But, in a soil, exposed to a water soil solution, the transport of cations and anions is at the molecular level - in and out of pores and their internal surface area. Yes, the formation of carboxyl groups on the surface of biochar is assumed to be at the surface. Does anyone agree or disagree with this statement? In other words, I find it plausible to believe carboxyl groups are formed within the whole, but probably not all, of a biochar particle.

I find it more relevant to think of biochar as existing in a soil solution exposed to all of the ions available.

Feel free to disagree.

Norm


Re: size of biochar for various aplications ?

Norm Baker
 

Stephen;

I have been making and using biochar in an experimental garden for about 12 years and am convinced it does not need to be ground or micronized except when one wants to put it through some sort of machinery for soil incorporation. In my experience, almost all of the biochar is broken up, with no easily seen large particles within one year. My question is how much of a faster response do you get for seed germination and early plant growth, or how much does it change the root membrane potential to reduce the energy required to take up nutrients?

Norm


Re: size of biochar for various aplications ?

mikethewormguy
 

Tom,

We get our fine powder typically from screening some of the 1/4 inch minus char..

One does not need alot of fine char powder to make black water.

Some of the answer regarding granulation will depend on what binder is used in the agglomeration process, as well as, how well and how long it take the granule to fall apart in water..

my 2 cents

Mike







Sent from my Verizon, Samsung Galaxy smartphone


2021 Community Wood Grant Program Awards: Biochar

Tom Miles
 

From USBI:

 

Congratulations Arizona Log and Timberworks, LLC for receiving a USFS 2021  Community Grant Program award! For the complete list see:

https://www.fs.usda.gov/science-technology/energy-forest-products/wood-innovation-community-wood-grants

 

2021 Community Wood Grant Program Awards


The Community Wood Energy and Wood Innovation Grant Program, launched in 2020, provides funding for grants to install thermally led community wood energy systems or to build innovative wood product manufacturing facilities. The Agriculture Improvement Act of 2018 (7 USC § 8113) and annual agency appropriations authorize and fund the grants awarded under this program.

Project

Organization

City, State

Award

Integrate a biochar plant, firewood kiln, and pole peeler into the production process at a forest products facility. (energy)

Arizona Log & TimberWorks, LLC

Eager, AZ

$479,721

 

 


2021 USFS Wood Innovation Awards for Climate, Carbon and Biochar

Tom Miles
 

From USBI

 

Following are grants awarded by USFS Wood Innovation program for climate, carbon and biochar. Fore the complete list see:

https://www.fs.usda.gov/science-technology/energy-forest-products/wood-innovation-grants

2021 Wood Innovations Grant Recipients


The Wood Innovations Grants Program, launched in 2015, stimulates and expands wood products and wood energy markets. Relevant legislation includes the Agriculture Improvement Act of 2018 (Public Law 115- 334) and Rural Revitalization Technologies (7 U.S. Code [USC] 6601). National focus areas include mass timber, renewable wood energy, and technological development that supports fuel reduction and sustainable forest management.

Project

Organization

City, State

Award

Stimulating the Production and Use of Biochar Through Carbon Markets

Climate Action Reserve

Los Angeles, CA

$113,417

Upgrading a Biomass Power Plant to Allow for Biochar Production and Increased Throughput of Forest Biomass

Pacific Biochar Benefit Corp.

Santa Rosa, CA

$247,000

Coordinate and Develop a U.S. Corporate Climate and Forest Products Strategy

Net Impact

Oakland, CA

$125,000

Expanding Markets for Hazardous Fuel Balsam Fir via the Low-Carbon Economy

University of Minnesota Duluth

Duluth, MN

$187,246

Develop Tools for Success for Biochar Market Development

University of Nebraska

Lincoln, NE

$118,431

Demonstrate Patented Technology to Decarbonize Wood Pellet Feedstock Resulting in CO2 Emission Reduction.

Lignetics, Inc.

Mifflintown, PA

$129,900

Biomass Generation with Biochar for Island Energy Resilience

Orcas Power & Light Cooperative

Eastsound, WA

$72,835

 

 

 


Re: size of biochar for various aplications ?

Nando Breiter
 

Hi Stephen,

I used smectite.

Interesting paper. Thanks for sharing it.

n

CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 1:12 PM Stephen Joseph <joey.stephen@...> wrote:
Hi Nando

What type of clay did you use?  

Smectite gives you the highest CEC and Kaolin the highest AEC (as a general rule) depending on the substituted elements in the clay lattice structure and thermal/chemical treatment.

Normally we add a little more total minerals (30%) to 70% fine biochar.  In fact we did an experiment in Tibet and the greatest pasture response was 50% 50% attapulgite clay : yak dung biochar mixture.  This has been published.

Regards
Stephen


On Fri, May 7, 2021 at 8:26 PM Nando Breiter <nando@...> wrote:
Ross,

Some years ago I tried a small experiment at the urging of Nikolaus Foidl. Ingredients, more or less, I don't remember precisely. Stephan Joseph might correct the ratios:

8 parts powdered biochar
1 part powdered clay
1 part powdered dolomite

Mix the powders together and add water. The powdered biochar and clay have negatively charged surfaces, while the dolomite is a double plus cation, so it acts as a so-called cation bridge. So these particles form mini-aggregates, and aggregates are what hold water in soil. The mixture I made held a lot of water and seemed to be very similar to a rich, black soil. Cation bridging between clay particles and particles of organic carbon is a known feature of fertile soil and is believed to contribute to the stabilization of organic carbon. https://www.jstor.org/stable/1468629?seq=1

Cation bridging is found in Terra Preta soils. While the char particles in TP have a large size range, the greatest percentage of them are around 20 microns in size, nearly all are bound to clay particles via a calcium ++ bridge. For reference, a human hair is about 80 microns thick.  Once a powdered biochar particle is bound to a soil aggregate, it will almost certainly stay put.

One advantage to powdering biochar is that it significantly increases the surface area exposed to the freely circulating soil solution. Here's a table that shows the quantity of particles and the total exposed surface area of a biochar particle that starts off as a 1 cm cube and is then reduced by half in size, one step at a time, to 10 microns. I calculated assuming a cube, which of course is not realistic, but the results are illustrative.

Size Quantity Total Surface Area cm2
1 cm 1 6
5 mm 8 12
2.5 mm 64 24
1.25 mm 512 48
625 μm 4,096 96
312 μm 32,768 192
156 μm 262,144 384
78 μm 2,097,152 768
39 μm 16,777,216 1536
20 μm 134,217,728 3072
10 μm 1,073,741,824 6144

Larger particles of char that have a developed internal pore structure may sorb mineral nutrients, but it does not seem to me that these nutrients are freely available to plants. Experimentation has shown that soil bacteria do not survive very deep in a char pore (depending on the paper, something in the range of 80 microns). These bacteria will of course depend on the nutrients, particularly dissolved organic matter, available in the soil solution. If bacteria can't get the nutrients they need deep in a char pore (80 microns isn't that deep), how is a plant root (reliably) supposed to do so?

Another advantage to powdering biochar is that the particles are then much more widely distributed throughout the soil.

Powdered biochar should not be surface applied alone, of course. It will wash away. And if it is mixed with pure sand as a substrate it might leech out. I don't know, I've never tried it. No practical reason to do so. 

Downsides to powdering biochar might be that it is relatively difficult to do if you don't have a proper mill. The material is more difficult to handle on its own. But in most circumstances, I don't think powdered biochar should be applied on its own.

Soil fertility is the result of a number of factors working together in concert. As such, I tend to think of biochar as a form of organic carbon that is produced by thermal rather than biological decomposition. Organic carbon is one instrument in the orchestra. The bits of stabilized organic carbon in soils of biological origin that are the backbone of soil fertility are very small.

Comments and criticism welcome.

Kind regards,

Nando






CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 10:12 AM d.michael.shafer@... <d.michael.shafer@...> wrote:
A paper presented on the Green Webinar a few months ago suggested that very small "dust" sized particles are actually hydro phobic.

M


On Fri, May 7, 2021, 6:36 AM Ross Hunt <rossahunt@...> wrote:
I have been using water and wood chipper to crush biochar. Most of it comes out as dust size (slurry of dust size particles)
Is there any data from studies on best crushed size biochar for types of soils for fertility and life for sequestering purpose ?
I read on a facebook posting that biochar dust in sandy soils will wash away into groundwater.
Also, might dust not have the benificial micro pores ?
Ross


--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


Re: size of biochar for various aplications ?

Tom Miles
 

Do fine particle have the same effect if they are granulated for convenience of handling and safety of application? There is clearly an additional cost for granulation.

 

Tom

 

From: main@Biochar.groups.io <main@Biochar.groups.io> On Behalf Of mikethewormguy via groups.io
Sent: Friday, May 07, 2021 5:42 AM
To: main@Biochar.groups.io
Subject: Re: [Biochar] size of biochar for various aplications ?

 

We like to use 1/4 inch minus wood biochar for soil applications and powder char, the finer the better, for liquid applications.

We have used bigger pieces (1/2 - 1 inch) of wood char produced from our fire pit char process in our garden soil.  We did this just because.


Re: Good Source for Small Amount of Biochar?

Charles Hegberg
 

By the cubic yard.  Generally we sell full supersacks but could break one down to a yard.  If you have a few 55 gallon plastic barrels we can provide that way as well.  Feel free to email or text me. 

 

From: main@Biochar.groups.io <main@Biochar.groups.io> On Behalf Of Allan Balliett
Sent: Thursday, May 6, 2021 11:39 AM
To: main@biochar.groups.io
Subject: Re: [Biochar] Good Source for Small Amount of Biochar?

 

 

Charles. How is it priced? Do you sell smaller ants?

 

Thanks 

 

 

On Thu, May 6, 2021 at 11:23 AM Charles Hegberg <chegberg@...> wrote:

Allan. 

I have material in Baltimore but not pre charged. You would have to do that. We can load in you truck as a super sack. 

 Charles H. Hegberg, President

reGENESIS Consulting Services, LLC

Infinite Solutions, L3C

256 Frederick Street

Hanover, PA 17331

410-218-1408 (m)

 

U.S. Biochar Initiative Board Member

USBI Biochar 2018 Conference (Past Chair)

 

"Promoting the Sustainable Production and Use of Biochar"

 

www.biochar-us.org

@USbiochar

Facebook US Biochar Initiative 

 

 

 

 


Urban "waste wood"

Dick Gallien
 

https://www.winonapost.com/Opinion/Letters-to-the-Editor/ArticleID/72386/Citys-upcoming-compost-site-decision


I wrote them in Duluth one yr. ago, but had no response.  They are 220 mi. north--not farm country.

What are the comparative costs?  In this U of Mn Duluth article, they mention making biochar from hi bred popular.

Cost of tillable land for 10 yrs. for one crop.  Planting, harvesting with a system like chopping corn for silage, drying, charring.

Urban "waste wood", endless free supply, log chipper, drying, charring.

Urban "waste wood"  endless free supply, cone/screw log splitter. air drying 

charring,   It costs Winona to stack their "waste wood", the officially accepted term for this natural resource, then stack the logs, because there's a nearby summer camp ground, then move it to burn on a small pile, which means the loader operator must stay there adding to the burn.  

Appreciate any thoughts on this last chance to save this farm--will be 90 in Nov..  

https://www.nrri.umn.edu/natural-resources-research-

institute/news/biochar 


Dick Gallien 
22501 East Burns Valley Road
Winona  MN  55987
dickgallien@...  [507] 312 0194
www.thefarm.winona-mn.us



FW: To post to Biochar Crusaders

Paul S Anderson
 

This message has been sent for posting in India to the Biochar Crusaders Whatsapp group.   It is also for all  on the Biochar Discussion Group.    The main activity thus far has been in Kenya, but much more to come in other countries.

 

Paul


Subject: To post to Biochar Crusaders

 

RK Metha,

 

Please post this attached document for all the Biochar Crusaders to see.     And add this comment if possible:

 

The RoCC X-Frame kiln does NOT need the hood and chimneys.   It can be made in Kenya for under US$100.   So it should be affordable when made in India for India.  

Length can be increased with two barrels end to end with support braces.   

Diameter can be increased to 36 inch diameter when using new sheet metal rolled into  C   shape and then have ends put on it.

Consider using larger diameter wheels, even bicycle metal wheel rims.

Two options for axle are shown:   1)  pipe all the way through the barrel, and 2) have axle “stubs” on each end.  

Note:   RoCC kiln technology is patented (pending) in USA and available for patents in other countries.  I am seeking appropriate “partners” regarding patents in India and elsewhere.  Usage is allowed for prototypes and pre-commercial efforts.

Further information about RoCC kilns is at     www.woodgas.energy/resources   

Contact Paul Anderson   psanders@...   about usage with rice husks, etc.

Sharing your experiences is expected.

 

Paul

 

 

Doc / Dr TLUD / Paul S. Anderson, PhD --- Website:   www.drtlud.com

         Email:  psanders@...       Skype:   paultlud

         Phone:  Office: 309-452-7072    Mobile & WhatsApp: 309-531-4434

Exec. Dir. of Juntos Energy Solutions NFP    Go to: www.JuntosNFP.org 

Inventor of RoCC kilns and author of Biochar white paper :  See  www.woodgas.energy/resources  

Author of “A Capitalist Carol” (free digital copies at www.capitalism21.org)

         with pages 88 – 94 about solving the world crisis for clean cookstoves.

 


Re: size of biochar for various aplications ?

mikethewormguy
 

We like to use 1/4 inch minus wood biochar for soil applications and powder char, the finer the better, for liquid applications.

We have used bigger pieces (1/2 - 1 inch) of wood char produced from our fire pit char process in our garden soil.  We did this just because.


Re: size of biochar for various aplications ?

Stephen Joseph
 

Hi Nando

What type of clay did you use?  

Smectite gives you the highest CEC and Kaolin the highest AEC (as a general rule) depending on the substituted elements in the clay lattice structure and thermal/chemical treatment.

Normally we add a little more total minerals (30%) to 70% fine biochar.  In fact we did an experiment in Tibet and the greatest pasture response was 50% 50% attapulgite clay : yak dung biochar mixture.  This has been published.

Regards
Stephen


On Fri, May 7, 2021 at 8:26 PM Nando Breiter <nando@...> wrote:
Ross,

Some years ago I tried a small experiment at the urging of Nikolaus Foidl. Ingredients, more or less, I don't remember precisely. Stephan Joseph might correct the ratios:

8 parts powdered biochar
1 part powdered clay
1 part powdered dolomite

Mix the powders together and add water. The powdered biochar and clay have negatively charged surfaces, while the dolomite is a double plus cation, so it acts as a so-called cation bridge. So these particles form mini-aggregates, and aggregates are what hold water in soil. The mixture I made held a lot of water and seemed to be very similar to a rich, black soil. Cation bridging between clay particles and particles of organic carbon is a known feature of fertile soil and is believed to contribute to the stabilization of organic carbon. https://www.jstor.org/stable/1468629?seq=1

Cation bridging is found in Terra Preta soils. While the char particles in TP have a large size range, the greatest percentage of them are around 20 microns in size, nearly all are bound to clay particles via a calcium ++ bridge. For reference, a human hair is about 80 microns thick.  Once a powdered biochar particle is bound to a soil aggregate, it will almost certainly stay put.

One advantage to powdering biochar is that it significantly increases the surface area exposed to the freely circulating soil solution. Here's a table that shows the quantity of particles and the total exposed surface area of a biochar particle that starts off as a 1 cm cube and is then reduced by half in size, one step at a time, to 10 microns. I calculated assuming a cube, which of course is not realistic, but the results are illustrative.

Size Quantity Total Surface Area cm2
1 cm 1 6
5 mm 8 12
2.5 mm 64 24
1.25 mm 512 48
625 μm 4,096 96
312 μm 32,768 192
156 μm 262,144 384
78 μm 2,097,152 768
39 μm 16,777,216 1536
20 μm 134,217,728 3072
10 μm 1,073,741,824 6144

Larger particles of char that have a developed internal pore structure may sorb mineral nutrients, but it does not seem to me that these nutrients are freely available to plants. Experimentation has shown that soil bacteria do not survive very deep in a char pore (depending on the paper, something in the range of 80 microns). These bacteria will of course depend on the nutrients, particularly dissolved organic matter, available in the soil solution. If bacteria can't get the nutrients they need deep in a char pore (80 microns isn't that deep), how is a plant root (reliably) supposed to do so?

Another advantage to powdering biochar is that the particles are then much more widely distributed throughout the soil.

Powdered biochar should not be surface applied alone, of course. It will wash away. And if it is mixed with pure sand as a substrate it might leech out. I don't know, I've never tried it. No practical reason to do so. 

Downsides to powdering biochar might be that it is relatively difficult to do if you don't have a proper mill. The material is more difficult to handle on its own. But in most circumstances, I don't think powdered biochar should be applied on its own.

Soil fertility is the result of a number of factors working together in concert. As such, I tend to think of biochar as a form of organic carbon that is produced by thermal rather than biological decomposition. Organic carbon is one instrument in the orchestra. The bits of stabilized organic carbon in soils of biological origin that are the backbone of soil fertility are very small.

Comments and criticism welcome.

Kind regards,

Nando






CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 10:12 AM d.michael.shafer@... <d.michael.shafer@...> wrote:
A paper presented on the Green Webinar a few months ago suggested that very small "dust" sized particles are actually hydro phobic.

M


On Fri, May 7, 2021, 6:36 AM Ross Hunt <rossahunt@...> wrote:
I have been using water and wood chipper to crush biochar. Most of it comes out as dust size (slurry of dust size particles)
Is there any data from studies on best crushed size biochar for types of soils for fertility and life for sequestering purpose ?
I read on a facebook posting that biochar dust in sandy soils will wash away into groundwater.
Also, might dust not have the benificial micro pores ?
Ross


--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


Re: size of biochar for various aplications ?

Nando Breiter
 

Ross,

Some years ago I tried a small experiment at the urging of Nikolaus Foidl. Ingredients, more or less, I don't remember precisely. Stephan Joseph might correct the ratios:

8 parts powdered biochar
1 part powdered clay
1 part powdered dolomite

Mix the powders together and add water. The powdered biochar and clay have negatively charged surfaces, while the dolomite is a double plus cation, so it acts as a so-called cation bridge. So these particles form mini-aggregates, and aggregates are what hold water in soil. The mixture I made held a lot of water and seemed to be very similar to a rich, black soil. Cation bridging between clay particles and particles of organic carbon is a known feature of fertile soil and is believed to contribute to the stabilization of organic carbon. https://www.jstor.org/stable/1468629?seq=1

Cation bridging is found in Terra Preta soils. While the char particles in TP have a large size range, the greatest percentage of them are around 20 microns in size, nearly all are bound to clay particles via a calcium ++ bridge. For reference, a human hair is about 80 microns thick.  Once a powdered biochar particle is bound to a soil aggregate, it will almost certainly stay put.

One advantage to powdering biochar is that it significantly increases the surface area exposed to the freely circulating soil solution. Here's a table that shows the quantity of particles and the total exposed surface area of a biochar particle that starts off as a 1 cm cube and is then reduced by half in size, one step at a time, to 10 microns. I calculated assuming a cube, which of course is not realistic, but the results are illustrative.

Size Quantity Total Surface Area cm2
1 cm 1 6
5 mm 8 12
2.5 mm 64 24
1.25 mm 512 48
625 μm 4,096 96
312 μm 32,768 192
156 μm 262,144 384
78 μm 2,097,152 768
39 μm 16,777,216 1536
20 μm 134,217,728 3072
10 μm 1,073,741,824 6144

Larger particles of char that have a developed internal pore structure may sorb mineral nutrients, but it does not seem to me that these nutrients are freely available to plants. Experimentation has shown that soil bacteria do not survive very deep in a char pore (depending on the paper, something in the range of 80 microns). These bacteria will of course depend on the nutrients, particularly dissolved organic matter, available in the soil solution. If bacteria can't get the nutrients they need deep in a char pore (80 microns isn't that deep), how is a plant root (reliably) supposed to do so?

Another advantage to powdering biochar is that the particles are then much more widely distributed throughout the soil.

Powdered biochar should not be surface applied alone, of course. It will wash away. And if it is mixed with pure sand as a substrate it might leech out. I don't know, I've never tried it. No practical reason to do so. 

Downsides to powdering biochar might be that it is relatively difficult to do if you don't have a proper mill. The material is more difficult to handle on its own. But in most circumstances, I don't think powdered biochar should be applied on its own.

Soil fertility is the result of a number of factors working together in concert. As such, I tend to think of biochar as a form of organic carbon that is produced by thermal rather than biological decomposition. Organic carbon is one instrument in the orchestra. The bits of stabilized organic carbon in soils of biological origin that are the backbone of soil fertility are very small.

Comments and criticism welcome.

Kind regards,

Nando






CarbonZero
+41 76 303 4477 cell / WhatsApp / Signal (https://signal.org/)


On Fri, May 7, 2021 at 10:12 AM d.michael.shafer@... <d.michael.shafer@...> wrote:
A paper presented on the Green Webinar a few months ago suggested that very small "dust" sized particles are actually hydro phobic.

M


On Fri, May 7, 2021, 6:36 AM Ross Hunt <rossahunt@...> wrote:
I have been using water and wood chipper to crush biochar. Most of it comes out as dust size (slurry of dust size particles)
Is there any data from studies on best crushed size biochar for types of soils for fertility and life for sequestering purpose ?
I read on a facebook posting that biochar dust in sandy soils will wash away into groundwater.
Also, might dust not have the benificial micro pores ?
Ross


--
Nando Breiter
http://biochar.info
CarbonZero Sagl
Astano, Switzerland


Re: size of biochar for various aplications ?

alaa alamiri
 

Dear all,

The links below are my papers, I think, they will help you to decide about better biochar size.






with best compliments

ALAA HASAN FAHMI
Bsc. Soil&water Sciences.
MSc. Soil Chemistry and organic matter
Ph.D. Environmental Soil Chemistry
Universiti Putra Malaysia - UPM
Working at : University of Diyala





On Friday, May 7, 2021, 02:36:42 AM GMT+3, Ross Hunt <rossahunt@...> wrote:


I have been using water and wood chipper to crush biochar. Most of it comes out as dust size (slurry of dust size particles)
Is there any data from studies on best crushed size biochar for types of soils for fertility and life for sequestering purpose ?
I read on a facebook posting that biochar dust in sandy soils will wash away into groundwater.
Also, might dust not have the benificial micro pores ?
Ross


Re: size of biochar for various aplications ?

d.michael.shafer@gmail.com
 

A paper presented on the Green Webinar a few months ago suggested that very small "dust" sized particles are actually hydro phobic.

M


On Fri, May 7, 2021, 6:36 AM Ross Hunt <rossahunt@...> wrote:
I have been using water and wood chipper to crush biochar. Most of it comes out as dust size (slurry of dust size particles)
Is there any data from studies on best crushed size biochar for types of soils for fertility and life for sequestering purpose ?
I read on a facebook posting that biochar dust in sandy soils will wash away into groundwater.
Also, might dust not have the benificial micro pores ?
Ross

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