Garden Ping!.......................
Older than Dirt Ping!..............
GFY
I called it. When I read the headline I thought that with all the rain washing out the nutrients from the thin soil it must be getting caught in lowland areas. I was thinking localized pits rather than near rivers.
It is human waste. They found where a population took a dump or emptied out the house pots.
I read years ago this came from low pyrolysis of wood, basically like making charcoal but not as carbonized.
This creates an amphipathic (water loving/lipid loving) sponge that holds on to both water and nutrients but doesn’t quickly decompose.
There was a YouTube video about it.
Near rivers and “contains large amounts of nitrogen, potassium, and phosphorus.…”
I bet the same could be said about the soil below heron rookeries.
In North America there used to be huge amounts of guano fertilizer under miles-long groves of passenger pigeon nesting trees.
But when that was used up the passenger pigeons were extinct so it hadn’t been replaced.
In these villages there would be lots of organic material brought in from open areas to thatch the big communal house and all the other buildings every so many years. Plus human waste, peeled bark, cordage making, food processing, etc.
Diana; I haven’t read this, but you might be interested! (Perhaps the remains of “middens” of giant sloths exterminated by the gentle “first peoples” ! Who knows!)
My hypothesis is that dark earths started from privy pits. People used charcoal from where they cooked a meal and dumped it in the pit to kill the smell. Once the pit filled they dug another. Eventually they found out that the former pits made great farm soil. The bacteria in the human microbiome bound those minerals onto organic molecules which then clung to charcoal instead of rinsing out of sandy soils.
Is this related to “Demetrius Earth”?
Good soil caused by build up of organic decomposing and plants like this???
Who knew 😎
1. LIDAR images show that thousands of years ago the Amazon had thousands more human settlements than it does today; that it once held a large population.
2. Many of the locations of the Amazonian “dark soil” correspond to where LIDAR (ground penetrating radar) images show outlines of ancient human settlement.
Graham Hancock takes the position that a very, very (during the last ice age) ancient civilization in the Amazon river basin created the black soil.
bottom land ping
“...and are most often associated with the accumulation of materials in soil after long periods of human settlement.”
Human waste, food caches, burn pits or campfires is my guess, ending up as spots rich with Biochar.
“Biochar is a charcoal-like substance made from biomass through a process called pyrolysis, which involves heating organic material in a low-oxygen environment. It is primarily used as a soil amendment to improve soil health and sequester carbon.”
You can make your own, buy it, or let Mother Nature do it. ;)
Ping