How it began
The system, known locally as ye-chan, developed on Inle Lake in Shan State, the second largest lake in Myanmar. According to the geographer Martin Michalon, quoted by NASA's Earth Observatory, ye-chan agriculture probably dates back to the end of the 19th century, but it was little known and little practiced until the 1960s, when new infrastructure made it easier to move crops from southern Shan State to the rest of the country.
How it works
Floating vegetation in the shallow lake, including water hyacinth, forms dense mats that trap sediment. After 20 to 30 years the mats, about one meter thick, can bear weight. Farmers saw them into strips, tow them to the stilt villages, load them with mud and silt, plant them and stake them with bamboo poles so they do not drift. Farmers also gather weeds from the lake bottom to build up the beds. Because the beds rise and fall with the water level they resist flooding, and they are tended from boats.
Who pushed back
The expansion has drawn concern. Between 1935 and 2000 the open water area of the lake fell from 69.10 to 46.69 square kilometers, a loss of 32.4 percent, attributed largely to floating garden agriculture on the western side. Michalon notes that the total lake area is relatively stable and that it is the open water that has shrunk as gardens spread, which led to misleading reports that the lake was drying up.
What changed first
Tomatoes became the main crop, accounting for about 90 percent of ye-chan production, with beans, cucumbers, gourds and flowers also grown. The floating islands produce enough vegetables to drive the regional economy. Farming boomed a second time in the 1990s as Myanmar moved toward a more market-based economy, and one study found that the area of floating gardens increased by 500 percent between 1992 and 2009.
Where it stands today
Hundreds of hectares of floating beds are cultivated, and the blurred boundary between land and water makes the lake hard to measure from satellites. The gardens, together with the leg-rowing boatmen of the Intha, are a major draw for visitors to Inle Lake.
