Paddy soils now and then

Abstract Research on modern paddy field soils in Southeast Asia by Kawaguchi and Kyuma has produced a new classification of ten soil types for growing wet rice. Further study has yielded five fertility classes and a description of the nutritive requirements for good rice yields. These data are reviewed with the aim of identifying prehistoric practices for choosing and modifying soil materials in order to maximize crop yields. Methods are being developed in Japan for identifying subsurface paddy fields without the recovery of actual field system features through excavation. Most of this work consists of phytolithic analysis by Fujiwara and colleagues. A review of this research is accompanied by the test results of phosphate levels under modern paddy fields carried out by the author and colleagues. It is concluded that the assumption that structured fields in the archaeological record were used for growing wet rice is potentially misleading without phytolithic evidence, and that phosphate tests are underuse...