Jomon People Sowed Rice: A Re-Examination of the Period of Influx of Continental Grains into Japan, the ‘Etsuji SX-1 Phase’

Abstract

It is believed that continental grains permeated the San-in or Kyushu regions in Japan towards the Final Jomon period. However, there are only three samples (a rice impression from the Itaya 3 site, Shimane Prefecture, and a foxtail millet impression from the Etsuji and Ishii-Iriguchi sites, the Fukuoka and Oita Prefectures, respectively) from the ‘Emergence phase of the Ridge-pattern pottery’ compared to the number of carbonised rice and pottery with grain impressions corresponding with the ‘Yamanotera/Yusu 1 Type phase’—considered as the next phase in the pottery chronology and a marker of the beginning of the Yayoi period defined by wet rice cultivation. Further, it is difficult to obtain carbon-14 dates of the evidence due to the lack of carbonised organic material at these sites. Consequently, whether these grains were cultivated in the area remains ambiguous. To address these issues, we used x-ray equipment and carbon-14 dating to re-examine carbides (grains) from the earthenware corresponding with SX-1—considered as the standard specimen of the pottery type of the final phase of the Jomon period—at the Etsuji site. Several seed impressions of cultivated plants, such as rice and foxtail millet, were detected, implying the possibility of grain cultivation in this phase and clarifying the chronological framework. The discovery of grains embedded in the potsherds is valuable because it questions the existing theories about the influx of continental grains in Japan and the period of their cultivation.