Mexico’s floating gardens are an ancient wonder of sustainable agriculture

Waterline is an ongoing series of stories exploring the intersection of water, climate and food, told through the eyes of the people affected by these issues. It is funded by a grant from the Walton Family Foundation.

SStanding among rows of juicy, lime-green lettuce and plump florets of broccoli, it looks like Jose Paiz could be the owner of a modern, high-tech farm. But the crops that bloom here, on the outskirts of Mexico City, are part of a thousand-year-old tradition.

“My ancestors were doing this before even the (Spanish) conquistadors arrived in Mexico (in 1519),” Paiz says, crouching down and picking up a handful of powdery earth from the ground. chinampaor ‘floating garden’, on which we both stand.

Found floating on lakes to the south of the Mexican capital, these highly productive man-made island farms date back to the time of the Aztecs or maybe even sooner — and now advocates say these ancient engineering marvels could be an important, sustainable food source as the city faces historic drought.

“My grandparents taught me the methods,” adds Paiz, 32, the fifth generation of his family to have one chinampero work in San Gregorio Atlapulco, a traditional working-class neighborhood about 10 miles south of downtown Mexico City.

Experts say that these chinampas, which have been recognized as a UNESCO World Heritage location, are considered one of the most productive agricultural systems in the world. The artificial islands are built by collecting large amounts of soil from the lake bottom and placing them on reeds, grasses and rushes in a mass that rises above the water. Farmers then plant a fence of it ahuejotesMexican willows, surrounding the plot to naturally protect against erosion. This system means that the chinampa’s soil is continuously enriched by nutrient-filled sediment flowing in from the surrounding ditches and canals, yielding multiple harvests each year.

“In the field of agriculture, they are one of the best examples of how humans can work together with nature,” says Lucio Usobiaga, founder of Arca Tierraan organization that provides technical and entrepreneurial support to local farmers in the area.

One of the earliest traces of the chinampas dates back to the 14th century, when the Aztecs arrived in the region of what is now Mexico City. That’s where they founded the settlement Tenochtitlan – which would become one of the most powerful cities in all of Central America – in the Valley of Mexico.

But as the Aztecs soon discovered, the valley’s marshy, lake-filled landscape was difficult to cultivate or farm. That’s why they came up with an ingenious plan to adapt to the environment: the chinampas.

A 2013 paper Professor Matthew Teti of North Carolina State University found that chinampa farms in the 16th century could produce thirteen times as many crops as dry land farming in the same area – a system that fed hundreds of thousands of people. According to the study, Chinampas are “one of the most intensive and productive agricultural systems ever devised.”