[chabons]

Here I was scanning the article for what they floated on. I had assumed it was a peat-bog type situation.

I guess the key benefit of this strategy is that the water level is high and the water is nutrient rich? Otherwise it's pretty similar to a standard canal irrigation setup.

[throwup238]

They replenished the dirt on the islands with night soil dredged up from the bottom of the lake every year so it was basically a mound of fertilizer that’s always soaked through with water.

It’s as close to an ideal growing condition as pre-industrial societies had.