Making biochar with oyster and coconut shells

This study featured some interesting breakthroughs:
More humus being created
Different microbes that help break down materials, and
Improved seed growth.
Partially attributed to increased Calcium in the soil.

Check it out:

John S
PDX OR
https://link.springer.com/epdf/10.1007/s44246-025-00249-x?sharing_token=kggGaKvl8pei2QvEldzZKve4RwlQNchNByi7wbcMAY4xjQ6bN2KYRiwpmDf5U1VZ9tSbw4O2fEADZ_nixSO-O8-NwE9yOxTqg3OC_2Nxie4fEUo0DWkI5VI7vX_S14gy2UN3G7fqERmHCp5OOYci5T9pXlvnX0CCWfj7QxJqi1Q%3D

Well, the title of the study suggests a lot of moving parts (see below), but the implications are interesting. Should I include my eggshells into a biochar process instead of simply crushing them in the compost? My tomatoes want to know!

I do eat oysters sometimes, and I think I'm going to put some in there next time.  It sounds like it could have some good effects.  

John S
PDX OR

Could be another good argument to include bones in your biochar. Also, as a chicken owner, I happen to have 40 lb bag of crushed oyster shell right near where I make biochar. Might have to throw a scoop into the next batch!  

Mike Farmer wrote: Also, as a chicken owner, I happen to have 40 lb bag of crushed oyster shell right near where I make biochar. Might have to throw a scoop into the next batch!  

Good idea!

I did a kontiki demo for the crowd at a regen ag festival last week and chucked an entire rack of beef ribs onto the burn as it was going. When we finished up with quenching, I invited folks up to find the bones. Good times.

Biochar newbie here but excited that this could be a key to my long term soil health goals.  I'm in rainy Western WA where apparently we have a lot of leaching of calcium which impacts our soil pH.  (I just had a soil test done and the pH is 5.9.)  I'm still trying to wrap my head around how that works and if there's a way to stop it from happening on my land such that my great great grandchildren don't have to keep importing lime, etc.

The biochar out of oyster shells is intriguing because I may be able to access large amounts of that for cheap.

Something that gives me pause though..... I am seeing reference in this forum in other posts though that there's a danger in making shells into biochar because you'll make quicklime???  John, what do you think of this?  Have you made biochar out of shells and not killed yourself?  

Its quite funny what comes up regarding new ideas, new tricks, new recipes.

I haven't seen mother nature providing any else, as what falls from the trees or decays above the soil right where the compost or lets say new fertilizer is made.

Shellfish usually doesn't fall from the trees so it might be a waste of time and money seen as a " naturally no need for"

but of course it is sure a beneficial addidtion to feed the soil life.

No bad feelings just it makes me laughing that people claim they are living by teachings of nature and try to invent the wheel again and again.

Biochar is created by regular bush fires naturally,
I agree and some snails might fall victims but I would no buy any shells to show mother nature I know better than her.

As said I write this just for the joke and not involves critics.

I am also in the PNW with acidic soils and lots of drizzle.  I made my biochar with oyster shells for a few years.  Then I discovered that ag lime is REALLY cheap.  The oyster shells are good, but they may take decades to incorporate into your soil.  Ag lime is powderized, so adding it to a liquid biochar drench will make it bioavailable quickly. I have been doing this for years. The soil is great when I look back into it and check into it.  The plants do better and the fruit tastes much better.

John S
PDX OR

Hi See, I live not far from the ocean, but my soils are depleted of calcium because of leaching winter rains (not as bad as the amazon!).  Indigenous people here definitely did prairie burning, and they also relied on the wealth of the sea for their diets, and so it makes sense to me that shells have a place.  Plus, there are PILES and PILES of them out at the beach at the seafood processors.  

To your other point ... it's sad that we're at a place where so much knowledge has been lost.  I can't do anything about the fact that my ancestors became disconnected from land and failed to pass down key survival wisdom.  All I can do now is learn and experiment!

John Suavecito wrote:I am also in the PNW with acidic soils and lots of drizzle.  I made my biochar with oyster shells for a few years.  Then I discovered that ag lime is REALLY cheap.  The oyster shells are good, but they may take decades to incorporate into your soil.  Ag lime is powderized, so adding it to a liquid biochar drench will make it bioavailable quickly. I have been doing this for years. The soil is great when I look back into it and check into it.  The plants do better and the fruit tastes much better.

Thanks John.  I have been starting to add aglime to my soil and even after one season I'm noticing the structure is improved.   I will definitely be adding it to the biochar when I innoculate!  (Right now I'm experimenting with small can retort in the fire of our wood fired bath.)   I think it makes sense to do that as a short term solution for the gardens and look at the oyster shells as a long term solution.  We have a large property and I'm pondering how to help the soil in my pastures of 10-15 acres.  That's a LOT of lime or biochar.  I'm collecting ideas of how I can raise the pH overtime and try experimenting with different things in different sections.   It's a daunting project.

Anyway, I like the idea of sourcing shells now while it's possible to transport them an hour from the ocean.  And I like the idea of leaving my descendants some insurance for soil health in the form of a big pile of calcium sitting in the woods.  

Don't forget to add seaweed.  I also add whole wheat flour, compost, worm castings, rotten fruit, rotten wood, and urine.  But add what you can get cheaply.  People with cows and chickens can add the manure, of course.

Yes I'm on a standard suburban lot, so the area may be similar, but the plot of land is different.
John S
PDX OR

Courtney Munson wrote:
To your other point ... it's sad that we're at a place where so much knowledge has been lost.  I can't do anything about the fact that my ancestors became disconnected from land and failed to pass down key survival wisdom.  All I can do now is learn and experiment!

As said no pun intended, it just made me giggling what people all try to imporove the soil and as you said.
It's also regional complete different. Near the beach shells are sure legal part of the nature's law, while in the middle of the jungle other requirements exist.

Wisdom is lost, is partially true and I like to add a phrase my Graddad used often.
"The money is laying on the street, but only a fraction of all humans know how to bend down to pick it up"

I put that into our modern life with the lost wisdom.
"It isn't lost, it is present all around us, but we need to know how to pick it up again.
You want to see a forest, so it's not the trees that block your sight and hide the forest"

The Indigenous here,  when they held dominion over these lands, had a lot of trading processes.  I would argue that people are part of nature, but that currently, most human societies are not in good harmony with the natural role of humans in the ecosystem.  People from the Cascades would trade obsidian with people who live near the Columbia river, who would trade salmon, who would trade shellfish with those on the Coast. People in the Willamette Valley would trade wapato and camas, two abundant vegetables.  I believe that the Indigenous had much better sustainability practices and understood their role in the ecology much better.  Because we are currently so out of balance with the optimal state of nature, we need to try to get it back to a situation in which we help nature and are helped by nature.  I believe that these biochar practices can build on the natural biochar that is created by fires, to make our ecosystems productive again for people and wildlife.  My use of biochar is in line with this ultimate goal, but I have much to learn in this journey, and I thank everyone on this list for helping me to understand how this might work.

John S
PDX OR