
Stopping Pollution with Pine Needles - prostoalex
https://www.economist.com/science-and-technology/2020/07/18/stopping-pollution-with-pine-needles
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lgleason
In the southeast of the US longer pine needles from varieties of pines such as
slash pine are used for garden mulch. Ironically, this was later in the season
than I normally do this, I just laid down 52 bales of mulch in my garden.

Here it is common for a few reasons.

1\. It is in-expensive (about $3.75 a bale). 2\. It provides insulation to the
plant roots to keep the soil warmer in the winter and cooler in the summer.
3\. On steep inclines it tends to knit together to stay on the incline to
prevent erosion. 4\. As it breaks down it amends the soil with nutrients.

The only negative is that you have to add new mulch every year because it
mostly breaks down after a year.

People who have pine tree farms use this as an extra revenue source.
[https://www.aces.edu/blog/topics/business-opportunities-
fore...](https://www.aces.edu/blog/topics/business-opportunities-
forestry/harvesting-pine-straw-for-profit-questions-landowners-should-ask-
themselves/) [https://www.carolinacreations.biz/blog/mulch-and-pine-
straw/](https://www.carolinacreations.biz/blog/mulch-and-pine-straw/)

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hedora
How do you deal with the soil acidity?

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lgleason
Many flowers etc. in my beds prefer acidity. If it gets too acidic some lime
can adjust things back.

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zoomablemind
> ... If it gets too acidic some lime can adjust things back.

You probably mean lye [1], which is alkaline to neutralize the acid.

[1]:
[https://en.m.wikipedia.org/wiki/Lye](https://en.m.wikipedia.org/wiki/Lye)

~~~
frank2
Lime is alkaline, too, and cheaper:

[https://en.m.wikipedia.org/wiki/Agricultural_lime](https://en.m.wikipedia.org/wiki/Agricultural_lime)

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neonate
[https://archive.is/t9qC2](https://archive.is/t9qC2)

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ngold
So the secret is making charcoal with pine needles at 550 degrees.

Thank you.

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panzagl
From what I remember when I lived in the South every 5 cu yards of pine straw
comes with a free copperhead, I wonder what they get in the Himalayas...

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cglace
When you buy pine needles in bales? I’ve been spreading pine needles since I
was 7 and not once have I encountered a snake in a bale of pine needles.

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lgleason
I think that's a joke. Snakes do like to hide out in loose pine straw.

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panzagl
Not in bales, more like when you know someone who knows someone who delivers
it by the truckload. Usually they were babies.

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14
I appreciate Pine trees even more now. I am in Canada and have access to many
pine trees. One time I wanted to do a bit of soldering but could not find my
flux. Small town had nothing anywhere near me so decided to see if I could
make it. Quick DDG search shows rosin flux you can make from pine sap so I
went to a tree, they all have gobs of sap dripping from some point, and
collected some dirty sap. Took this home and soaked and stir it in pure
isopropyl alcohol. Ran through a coffee filter and just let most of the
alcohol air dry away. I love my flux it smells great works perfect and I know
where that puff of smoke is coming from now. Felt rewarding as well 10/10 will
keep doing this.

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JanSolo
Interesting research, but utterly impractical. Are they proposing to harvest
all the pine needles from all the forests in the Himalayas, convert them to
charcoal and then use that to filter the Ganges? How much do they have to
spend on this?

It's a fun mental exercise, but it's so far from realistic that it's funny.

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antisthenes
You'd be surprised what is realistic when the labor is pine needle cheap.

I wouldn't be surprised if you could pay some of the locals living there
$5-10/day to collect pine needles, and have them end up better off than they
are now.

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BrandonMarc
Moreover, in western China the labor isn't cheap, it's free. (Uighur slavery)

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el_don_almighty
I can't imagine 6 tonnes of charred pine needles dumped in the Ganges
effectively lasts more than a day for the purposes of heavy metal absorption.
The math is beyond me, but it doesn't seem overly difficult. Especially when
you consider that the needles don't show up all at once. They fall from the
sky one at a time. After the first harvest, little Jimmy will be wandering
through the once-lush, and now barren pine wasteland individually picking up
pine needles with an eyebrow tweezer. It's interesting, but probably only
"three legged dog" interesting.

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hinkley
You are also strip mining one biome to try to save another.

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catchmeifyoucan
Interesting article, but I don't see the original research linked. There isn't
much content here to say the effectiveness of the pinecones on the water
purification. I was also confused with the 550 degrees vs 35 degrees
comparision. I'd be curious to see if pine cones can have an impact on
desalination as well.

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Theodores
Pine needles are great for scrubbing pots and pans if camping. But we don't do
that. It might be green and practical but it doesn't happen.

The same with this story, great in principle but not going to happen.
Pollution needs to stop at source and you need legislation and enforcement for
that.

