Abstract
Map published in 1910 suggests that the marginal zone of the Chao Phraya valley has been occupied by two types of rice culture which originated from two regions having different cultural complexes; one is "Fai" type rice culture origination in intermountain basins to the north, and the other is "Bo" type rice culture possibly connected with the Khorat plateau. The former is characterized by "Fai" (dam) and transplanting, and the latter by "Bo" (farm-ponds) and mixture of transplanting and broadcasting. The both types are independent of the so-called flood irrigation rice culture in the backswamp area.
