headspace-hotel:

oftengruntled:

headspace-hotel:

headspace-hotel:

oh yeah are we gonna talk about how the basic sand/silt/clay soil diagram is super misleading?

I feel like it’s got to be a relic of like, the 1940’s that has just stuck around in the same way other outdated models have.

Sand, silt and clay aren’t ingredients, they’re particle sizes, and no amount of combining them will make soil if there’s no organic matter.

I’m looking up soil types and finding websites full of the wrongest statements ever.

Could you explain what’s wrong with those statements?

Well, basically, clay, sand and silt refer to sizes of mineral particles.

Clay being the smallest, and sand being the largest. It keeps going—there’s gravels, and cobbles, even. (The definitions of these terms are actually very contentious in geology.)

Chalk is not a particle size at all, it’s a carbonate rock. Soils that form on top of carbonate rocks are generally pretty alkaline. Alkaline is a “type” of soil but it’s got fuck all to do with the previous three.

Peat is what forms when organic matter decays in anoxic conditions in a wetland. It stores carbon. It’s neat.

The crucial problem here is that soil is not minerals. It contains minerals, but no amount of combining sand, clay and silt will create soil, ever. Adding sand to a clayey and silty soil doesn’t make better soil, it makes some kind of evil, useless concrete.

The organic matter is the crucial component. Even that’s understating it. Healthy soil doesn’t just “contain” organic matter, it is Literally Alive, full of microbes, mycelium, roots, and bugs.

Soil isn’t a substance. You can’t create it by stirring up ingredients. It’s a living metropolis, almost an organism. It’s full of order and communication. Soil is the plants that grow in it and the fungi that breaks down the plants when they die. Ants are a type of fully autonomous soil particle