Re: Sterilize Biochar Charged with Urine #urine

Kevin McLean

Thanks, Frank.  We are moving toward this model which allows poor smallholder farmers to collect, charge and store biochar year round:

Put an empty charcoal/rice bag in a hole in the ground.  These inexpensive PP bags are porous.  As the char is made, add it and urine to the bag.  When the bag is full, the char should be charged and excess liquid will have drained away.  Put the bag of biochar out and store it for the planting season.  Put another empty bag in the hole and start the process again.

Most smallholder farmers have little or no manure and don't know how to compost.  We will recommend they add whatever manure they have to the biochar.

On Wed, Sep 23, 2020 at 6:33 AM Frank Strie <frank.strie@...> wrote:

Yes Kevin,
your description of reasoning , methodology, time allowed and credible considerations  are all aiming at best practice and superb developments.
If you make the biochar you may like to quench and soak the char in the urine at the earliest (hot, warm, ultra-dry) stage. The follow the process as you outlined.
Have lots of productive fun and please take photos of the effects your Biochar process has on the production in the garden and on the land to share here with the network/ discussion group.
Best regards and thanks for sharing

From: <> On Behalf Of jim karnofski
Sent: Wednesday, September 23, 2020 6:17 PM
Subject: Re: [Biochar] Sterilize Biochar Charged with Urine




Urine charged biochar:


The purpose of using urine-soaked biochar is to recycle nutrients and charge the dry, sterile biochar.


First, I mix in active compost with the sterile char so there are hungry microbes lurking when the urine is poured through the mix.


Second, the container is large and has small holes in the bottom allowing the excess liquid to slowly drip out the bottom.  You will find contaminated water strained through charcoal comes out mostly pure as the nutrients are stripped from aqueous solution to reside within the biochar.


Third, this charged biochar is then mixed into the rough side of my compost pile which helps preserve the detritus from gassing off as it rots while also integrating with the other soil microbes.


Fourth, the working raw pile of compost is turned into a finished pile of compost to sit until cool.


By the time this material is applied to the garden soil, the microbiology has done its magic. No worries. Aerobic compost has a healthy smell with dominant non-pathogenic bacteria that have their way with the bad bacteria.


If plated and isolated very carefully, healthy soil probably contains something of everything in its makeup. Immerse into this biological cloud sans mask and gloves. Eat the occasional raw beet, carrot, or potato fresh from the garden with a patina of dirt. It's all good.


Just do it because it is the right thing to do.








From: <> on behalf of Kevin McLean <info@...>
Sent: Saturday, September 5, 2020 5:09 AM
To: Biochar Listserv <>
Subject: [Biochar] Sterilize Biochar Charged with Urine


Does biochar charged with urine need to be stored for a month before application?


The WHO recommends that urine to be applied as fertilizer on food crops that are processed should be stored for a month to kill pathogens.  Urine should be stored for six months for crops that are eaten raw.  Is there a similar storage requirement for biochar charged with urine (or manure)?


Thank you,



Kevin McLean, President


Tampa, Florida, USA

+1 (813) 505-3340



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