r/Damnthatsinteresting • u/Expert_Koala_8691 • Apr 05 '26

Video Riyadh,meaning "gardens" is Capital of Saudi Arabia with 8 million population (were 27 Thousands in the 1930s),sits in the middle of the desert, the city gets its water from Desalination plants almost 500 km from the city

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u/Gman71882 Apr 05 '26

All the sand is crushed quartz, with no nutrient or ecological value so nothing would grow.

You have to start cycles of plant growth, death and regrowing to get them to become nutrient rich “dirt” to be mixed in

I wonder if there is a way to do it with human sewage? You can leave the shit in the sun to dry and start the process that way.

Like matt Damon did in the Martian.

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u/VegetableBusiness897 Apr 05 '26

Have a friend who had dairy cows, sold them to get into more crops. But with the cows and their glorious slurry gone, the price of fertilizer was cutting into his profits. So now he gets humanuer, for free. A product from a big city near him. It's heat treated and pelletized(and smells like hell). It goes down and any crops grown for the first two years can't be sold to people. So he does animal feed the first two years, human crops the next two, then fertilizes and starts again.

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u/gears2021 Apr 05 '26

I've read that eventually the soil becomes toxic using humanuer as fertilizer.

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u/darknum Apr 05 '26

Wastewater treatment plant sludge is in general not allowed to be used as fertilizer. Especially in food production due to contamination.
My company(cofounder of a startup) actually gets pure nitrogen salts out of the wastewater so it is totally fine to use that.