Pottery of the time was low-fired and did not generally reach vitrification, and it was not glazed with a silica-based glaze that would seal it.
So over time this pottery would absorb water. And especially low-fired bits could totally break down.
Source: amateur ceramicist, and I have first-hand experience with cone 6 clay (vitrifies at 1200c) bisc-fired to cone 04 (1060c) and crumbling to bits when left in water too long.
to add some context, in modern gardening things like crushed vermiculite are a common soil amendment. being a porous absorbent mineral, it serves the same purpose.
Not to mention terracotta is a very common material for potted houseplants and container gardening. Terracotta is low-fired, non-vitreous and porous to water, giving it nice breathability and water absorption characteristics.
There are also long-necked terracotta bottles (called ollas) you can buy (or DIY) which you bury in the ground. You fill the bottle with water and the terracotta itself acts as a wick, providing a slow release continuous underground water source for plants to access.
I have some reproduction native American pottery from the upper great plains. They're pretty neat as they have round bottoms. Just holding it feels like given enough time it would break down and melt for sure. It feels very porous.
There’s a type of low fired clay used in bonsai soil and a harder one used in hydroponics. Good for retaining moisture and they don’t swell and shrink with water.
Primitive Technology on YouTube does this repeatedly.
You make a hole or find a piece of slate for processing, you mine clay from a stream bed, and then you make your first pot as a tool for moving water, the second pot for making food, and before or after the second pot you make clay bricks to build a kiln to high fire other things more efficiently - less fuel and more multitasking of other tasks.
I seem to recall one or two doing this. But i suspect the reason they don't is cause they don't need to.
They all have a pot already. The benefits of more pots seems low. Conversely the calorie cost seems high (if only just collecting clay and cutting wood to fire it.)
On Alone thd priorities are shelter and food. Clay pots seems like a luxury in terms of utility use and energy cost.
Digging in arctic climates is just difficult. Soils freeze and gel.
Digging in semi-degraded postglacial till filled in with a few conifers (the Great Slave Lake site is largely talus/scree) is not especially productive in terms of clay.
I would love to see them invite Primitive Technology's John Plant on the show. I do understand if North Queensland is more his climate though.
If you try to make a planting bed in any settlement that’s more than say 100 years old on a site that was continuously lived on, you are guaranteed to come across at least some shards of glass, pots, plates, etc. Even if the spot was never explicitly a trash mound. Things break, people usually try to pick them up and put in trash, but (especially in grass) miss pieces. When kids break stuff you often don’t want them picking up sharp objects. Things get stepped on and pressed into soil. Many many reasons to find pottery shards where they seemingly don’t belong.
Also learning about this today. Apparently they're bad for ecosystems that had evolved with slowly decaying organic matter (because they eat it all quickly). In particular forests.
At least in my education they have always been framed as a vital component of the ecosystem and a sign of healthy soil. It's interesting to learn that's not true.
To some extent it's a matter of definition, and whether being caused by humanity means it's bad. After all, the native earthworms would eventually have migrated north and caused similar changes.
Is it bad that redwoods are doing very well in the UK?
There's invasive species that are hugely problematic, converting whole forests from fungal decomposition of leaves to bacterial (changing the soil conditions quite a lot).
I've read this, but I'm not 100% clear on this. I think it's probably entangled with the glaciation / interglacial transition, which happened relatively recently. Earthworms are invasive in Michigan, but so are _trees_ in that timescale. It seems like having a foot thickness of forest duff decomposing slowly is probably not a very ecologically stable situation, and might be a temporary phase as the forests creep northwards and the temperatures creep up. Earthworms are not especially frost-hardy, and need to burrow deep enough to survive frost, which is physically difficult as you go farther north.
Has a drastic change occurred in the forest floors of, say, temperate Georgia?
A lot of these observations about the miraculous soil caretaking of the elder Native Americans are in all likelihood just "Look at this garbage dump, so fertile, such agricultural skill!"
Broken half-fired terra cotta is effectively unusable rock. Terra cotta is semi-disposable, so lots of potsherds are produced per person-year before plastics/glasses/metals are introduced. It's the single most common and best-preserved archeological artifact. Broken pottery was used in place of sand to stabilize the clay in new pottery, but other than that it doesn't have many special qualities.
If you added the pottery fragments to the compost pile they would be “baked” again, albeit in a very different environment, and the finished product would have structural diversity closer to soil. Normally that would be rocks, but if your goal is to grow food clay rocks might be better for many reasons.
You're all overthinking it. They dumped their kitchen waste in the fields, and it happened to contain broken pottery too. It's the same for other archeological sites all over, many are waste dumps that contain interesting objects.
Does this matter? That is extremely difficult to differentiate via the archaeological record, so most archaeological research simply abandons the distinction. You should essentially never read intention into archaeology unless someone makes an extremely strong case the alternatives might be firmly excluded. As an example for a strong case of intention: if you find twenty skulls with pickaxes in their heads lined up on a shelf in an underground cubicular room, you should probably not assume this is a coincidence.
If you're reading about the use of pottery in soil, it does not matter what the people intended—at least, not as a primary concern. It is easy to read intention into headlines though.
This is the intention the previous poster was countering:
> These discoveries suggest that the area’s Indigenous farmers may have dumped their household waste and the remnants of fires onto their fields, using them as compost
So over time this pottery would absorb water. And especially low-fired bits could totally break down.
Source: amateur ceramicist, and I have first-hand experience with cone 6 clay (vitrifies at 1200c) bisc-fired to cone 04 (1060c) and crumbling to bits when left in water too long.