Thread by @SarahTaber_bww

close- grazing doesn't "rebuild nutrients" per se, they're just pooping out nutrients they ate that already came from the soil.

Grazing *does* rebuild organic matter. Cow guts break tough plant parts into nice soft squishy soil parts.

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"Organic matter" is just the black spongy stuff left over after things rot. (Plants, poop, dead bodies, etc.)

Without OM, dirt is just sand & clay. Either it's way too tight & doesn't let roots through, or it's super loose & can't hang onto water.

Organic matter is what turns sand & clay into proper soil. It's basically a sponge; holds water & keeps dirt from drying out immediately after rain.

In tight clay soils, also gives the soil more "spring" so it doesn't turn into a mud slick after rains.

It's the reason darker soils tend to be more "fertile." "Fertility" ain't just about nutrients, it's also about texture. You want it fluffy & spongy.

(note: nobody @ me about soil microflora, this thread is the reader's digest version)

Adding nutrients doesn't help if your soil still has bad texture. Roots are still thirsty and/or can't grow, bc the soil is just sand & can't hold onto water, or is too tight & crusty bc it's clay.

Organic matter does all this heavy lifting, even though it's usually a very tiny part of the total soil makeup.

"Good soil" starts at about 2% OM. Soils with less than that get noticeably hard to work with.

If you go above 2%, you're living fat & happy.

And fun fact- organic matter is great for our new best friend, carbon sequestration.

Every 1% OM you can add to soil sequesters 2-3 tons of carbon from the atmosphere.

Here's the thing: OM isn't forever. It's kind of like ... a kid, eventually it grows up into carbon dioxide.

So if you wanna have high-OM soil, you have to keep adding OM as fast or faster than it breaks down into CO2.

This is where the cow poop comes in. Ruminants are just really phenomenal at turning huge amounts of plants into OM, a lot faster than the plants can break down on their own.

They're walking shit factories and I say that with the highest respect

And in arid regions, those plants don't break down at all. They just mummify. So if you're in a dry place & want to have good soil that hangs on to your limited amt of rain, ruminants. are. mandatory.

(note: "overgrazing" in dry areas isn't the ruminants' fault. that comes from humans from wet places like NW Europe transplanting half-assed livestock practices that they could get away with in places w high rainfall, to dry places.)

Fun aside, the Great Plains are dry enough that plants don't break down well on their own most of the year.

That rich prairie soil? Kiiiiinda comes from the grass.

But really, it's millennia worth of bison poop. That we're just kinda mining right now til it runs out.

And "mining it" means "letting it turn into CO2."

Conversion of soil OM into CO2 dwarfs every other source of CO2 that goes into the atmosphere.

"In 2008, the global total [of soil respiration] reached roughly 98 billion tonnes, about 10 times more carbon than humans are now putting into the atmosphere each year."

nature.com/news/2010/1003…

Not doom & gloom! This is actually really good news, because adding OM back to soil is *really easy, cheap, and doable within a short timespan.*

In fact ... since the best way to add OM to soil is smart livestock rearing, you can actually make money at it.

Which means YOU DON'T HAVE TO WAIT FOR TREATIES AND GOV'TS TO GET THEIR SHIT TOGETHER. YOU CAN JUST. DO IT.

Y'all, pastured livestock works *really well* to stuff carbon into the soil.

I've been to farms where the soil's just dried-up white beach sand w 0% OM (ah, FL).

But their neighbor who runs pastured cattle's got thick, moist, chocolate cake-looking dirt at 4-5% OM.

That's 8-12 tons of C sequestered per acre, & it only takes 2-4 years to get there. It's fast, it's effective, & you can even make a good living doing it. Pastured livestock ftw

gonna tag this whole thread now #climatechange #ClimateAction

*note: this thread is geared towards arid regions & grasslands

...cutting down forests to raise cows is a non-winner, carbon-wise