chinampa
Chinampa is a term describing a method of ancient Mesoamerican agriculture which used small, rectangle-shaped areas of fertile arable land to grow crops on the shallow lake beds in the Valley of Mexico. They are sometimes refered to as floating gardens.
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The Aztecs & they are called chinampas.
Polders are low-lying plots of land protected by dikes from a body of water. Chinampas are built up plots or "floating gardens" surrounded by water.
The Aztecs would take several large mats of floating plants and stack them on top of each other on a mud flat. Canals were then dug round them for drainage. Waste and compost was added on the top. They measured 10 x 110 meters and were set out in a grid pattern. They were used to grow root vegetables, grain and fruit. In 1519 there were about 100,000 people living off 10,000 hectares of chinampa in the Mexican Basin.