The floating garden beds are formed by extensive manual labor. The farmers gather up lake-bottom weeds from the deeper parts of the lake, bring them back in boats and make them into floating beds in their garden areas, anchored by bamboo poles. These gardens rise and fall with changes in the water level, and so are resistant to flooding. The constant availability of nutrient-laden water results in these gardens being incredibly fertile. Rice cultivation is also significant.

http://en.wikipedia.org/wiki/Inle_Lake