composting eggshells...and eggs...

I was poking around the web and ran across:

https://www.gardenmyths.com/eggshells-decomposition-study/

The page supports the premise that eggshells don't decompose and don't add much to the soil.

Most of the eggshells I add to the garden were dried and blended into a powder. I add it to beds, compost, and anywhere worms are. Wet eggshells, like we get from other people in plastic bags, are usually just crunched up wet and added. I'm sure that the larger the pieces, the longer it takes to break down but can't believe the rather pointed language on the site showing eggshells don't break down and don't add much. I also spread a fair bit of crushed oyster shells for the birds. Whatever they don't use becomes part of bed soil. I know they will take a while to break down but eventually everything should.

Does anyone else have input here? One of my next compost input-sourcing plans are to find a nearby larger supply of waste eggshells, dry outside on screens and use the blender to reduce size and make a spreadable powdered additive to my soil.

Interesting, but I am not sure what the takeaway is.

What does the fact that large, undisturbed chunks of eggshell do not decompose in neutral soil mean as far as including them in compost or not?  What I glean from this very small study is that maybe we should not rely on uncrushed eggshells as a *mineral* amendment to the soil, because likely the calcium is not easily released into the soil.

However, there are other reasons to keep adding them to compost in my point of view:
- as a textural amendment to the compost, possibly aiding in aeration
- as grit for birds and other critters that need that for digestion
- because they don't hurt and I don't have any other use for them.

Plus, we already know that organisms -- including but not limited to fungal mycelia, plant roots, lichens, and probably many tiny members of the animal kingdom -- tend to negotiate for the minerals they need in soil by either secreting acids directly to dissolve what they need or bribing other organisms to do that by releasing secretions needed by the other organisms.  So even if the soil is  broadly neutral or even basic en grosse, the calcium from the shells might usefully supplement your soil life and nutrients.

I also thought it odd.  But, happily today I made a deal with a local small bakery to get their eggshells. I could be a lot. I have some old window screens I hope to dry them on and the nutribullet makes short work of dried eggshells. I won't be able to dry all of it, but the others will just be crushed a bit and added to compost, containers, and beds.

 I think of it as similar to bonemeal... it may take years to break down.  but that means a small but steady supply being released over a long time frame.

I like Eliot Coleman’s story about building soil on his farm and being told that “it was a waste of time to add oyster shells because they would take many years (30?) to break down...” His take away was “that’s great, I’ve got that taken care of...”
So, are you correcting a deficiency for this year, or preventing it into the future?

I dry, then grind my eggshells as finely as I can. Then I often give them back to my hens in their fermented feed.

Sometimes though, I add the eggshell powder to a large 5 gallon bucket, then I barely cover them with white vinegar. It bubbles quite a lot, so do it outside and leave lots of empty space in the bucket. When the bubbles die down, I let the mixture sit a few hours or overnight. Then I dilute the mixture quite a bit with water and directly feed my plants. There will still be some eggshell powder that doesn't dissolve, but I add that to the compost bin. It's more work involved to do all this, but it releases the calcium into a soluble form more quickly.

Kenneth Elwell wrote: So, are you correcting a deficiency for this year, or preventing it into the future?

A little of both but I'm definitely in for the long-haul. In the near term, I've been building the soil in most of the beds from scratch as I removed existing soil due to coal combustion byproducts, etc. I do also scatter crushed oyster shell for the local birds all over the beds. What they don't get, stays in my beds. What they do get, eventually gets released as fertilizer. Win win win.

Just got a text from the owner saying he's got a 5 gallon bucket full.

I hadn't thought about dissolving in vinegar. Thanks!

echo minarosa wrote:I hadn't thought about dissolving in vinegar. Thanks!

Here is the video that inspired me. https://www.youtube.com/watch?v=sU5TXvjsTv8

I don't necessarily agree with the video's assertion that a calcium deficiency is always the cause of blossom end rot. I've heard from several master gardeners that it's often caused by a plant's inability to uptake the calcium that is already present in the soil. Take that for what you will, I just thought it was worth mentioning.

I have learned by experience that whole eggs in compost have a magical ability to stay unbroken until their smell reaches the maximum possible nastiness level.

We use eggshells in the garden all the time -
quick rinse and leave to dry on the dish drainer, then crunch into an old tin to store up until the tin is full. I crunch by hand and sprinkle on the garden... I like to think it helps deter slugs (but I don't think it does)... I do know it looks like confetti for a week or two and then the shells just seem to disappear!
My husband whizzes to a powder in an old coffee grinder and spreads on the lawn (yes... sigh... I'll get rid of the lawn someday...)

Yes just putting eggshells in the garden is not a quick return.  So try this.  It is a practice in Natural Farming!

http://culturalhealingandlife.com.www413.your-server.de/index.php?/forums/topic/40-inputs-section-5-water-soluble-calcium-wca/

Stacie Kim wrote:

echo minarosa wrote:I hadn't thought about dissolving in vinegar. Thanks!

Here is the video that inspired me. https://www.youtube.com/watch?v=sU5TXvjsTv8

I don't necessarily agree with the video's assertion that a calcium deficiency is always the cause of blossom end rot. I've heard from several master gardeners that it's often caused by a plant's inability to uptake the calcium that is already present in the soil. Take that for what you will, I just thought it was worth mentioning.

Yes, the reason for a deficiency is not always due to a lack of the mineral.  If only it was so simple.  Calcium issues are typically indoor problems or in plant beds that would naturally reduce the amount of available calcium over time.  Often seen where people put in bag soils and those soils become depleted of calcium over time without amendments/inputs.

Have a great day, hope that helps at all or just preaching to the choir for the most part!

I heard before about the reaction of vinegar and eggshells for releasing calcium carbonate. In fact i have read that dissolving eggshells in vinegar could be also part of human diet to provide calcium in some circumstances.

I also use to dry them and make them powder with a coffee grinder. Then I add them to the compost pile, where I presume that will be decomposed sooner or later, but sure faster than just cracked.
And also, I add eggshells powder to the vermicomposter. It seems it is also a good adding for the worms diet. Finally will end up into plants soil too.

I've used powdered eggshells primarily as grit, as well as to control pH, in vermicomposting. I'm not raising worms at the moment, but when I am, they always get first dibs on my eggshells.

Once in a while, when I've accumulated a ridiculous amount of eggshells, I'll break them up into coarse (up to 3/4") pieces and use them as a mulch on container plants. If they happen to get turned and mixed into the soil while harvesting or transplanting, they don't lock up nitrogen like wood does. It's a bit trickier for me to keep the soil for container plants in balance than it is in regular garden beds, and I've tended to have more problems with acidity than alkalinity, but the eggshells have been helpful there.

As for whole eggs that have gone off, or are suspect, I dig a little trench around existing plantings and and toss them in, making sure they all break before I cover them. I always assumed they would, in time, break on their own, but no they don't. Hitting a bunch of year-old rotten eggs while digging to move a garden bed--there is not enough "Eew!" to describe that, LOL.

Melissa Bee wrote:As for whole eggs that have gone off, or are suspect, I dig a little trench around existing plantings and and toss them in, making sure they all break before I cover them. I always assumed they would, in time, break on their own, but no they don't. Hitting a bunch of year-old rotten eggs while digging to move a garden bed--there is not enough "Eew!" to describe that, LOL.

They're not breaking down even after they're broken? That must be horrible! :)

echo minarosa wrote:

Melissa Bee wrote:As for whole eggs that have gone off, or are suspect, I dig a little trench around existing plantings and and toss them in, making sure they all break before I cover them. I always assumed they would, in time, break on their own, but no they don't. Hitting a bunch of year-old rotten eggs while digging to move a garden bed--there is not enough "Eew!" to describe that, LOL.

They're not breaking down even after they're broken? That must be horrible! :)

The contents of the eggs that broke when going into the bed did break down, no problem.

The contents of the eggs that were still intact when I buried them, however, did not break down--or, rather, they just went bad within the shells, without feeding the soil. Because unbroken eggs, as it turns out, will take a very long time to finally break when buried. I thought the shells would break down a lot faster than they did, but they are remarkably persistent.

Once those nasty, year-old eggs were broken and re-buried, the contents were finally available to soil microbes and other life, and their contents quickly became part of the soil.

So that was how I learned that if you're going to throw bad eggs in to a garden bed or compost pile to rot, make sure they all break open before burying them. Don't think you can just avoid the stink by burying them intact. I don't know how long an intact egg can survive being buried before finally breaking down, but it was a heck of a lot longer than I would have imagined, and they stunk a whole lot worse the second time around, LOL.

echo minarosa wrote:I also spread a fair bit of crushed oyster shells for the birds.

Interesting, for the birds? What do oyster shells do for them?

I spread crushed oyster shell for two reasons...birds and the garden. I scatter them in the beds and birds get what they need for their crops in order to grind food...like the seeds I also feed. Any breakdown goes through with the droppings, so I may get some amount of that back. Whatever they don't use still stays in my garden for long-term minerals.