Positive Study on the Presence of Rice Cultivation before the Beginning of Rice Cultivation in Paddy Fields

检测陶器碎片中含有的植物蛋白石，是证明在陶器制作时期之前存在提供被检测植物蛋白石的植物的有效方法之一。在这项研究中，研究了水稻（Oryza sativa L.）和其他禾本科作物在日本开始种植的时期。结果总结如下：1。在上野原遗址（鹿儿岛）的调查结果显示，在公元前9000年左右积累的麻草层正下方的土层中发现了禾草（Echinochloa crusu -galli Beauv.）植物蛋白石。稗子和日本谷子是可食用的，而且关系密切。因此，这些结果表明，日本谷子的原始种植可能在于门时期早期就开始了。在青森县三原山遗址出土的陶器碎片中发现了大量的禾草蛋白石。考虑到这个遗址的规模和特点，有可能种植过日本谷子。3所示。从冈山大学遗址（冈山县）和minimizte遗址（冈山县）出土的陶器中发现了于门时代晚期植物蛋白石的情况。据估计，这些陶器制作于公元前3500年左右。这一结果表明，在这一时期，日本西部已经开始种植水稻。在长崎县的Hietabaru遗址的调查中，在距今约3600年的Mutsuki火山碎屑流积聚的火山灰层下的土层中发现了水稻植物蛋白石。考虑到该遗址的位置和其他植物遗骸的存在，这里的水稻种植可能是在旱地进行的。

To detect plant opals contained in pottery sherds is one of effective methods to prove the existence of plants which supplied the detected plant opals before the period when the potteries were made. In this study, it is examined about the period the cultivation of rice (Oryza sativa L.) and other Gramineae crops began in Japan. The result is summarized as follows.1. The situation in the early stage of Jyomon periodAs a result of the investigation in Uenohara site (Kagoshima prefecture), Barnyard grass (Echinochloa crus-galli Beauv.) plant opals are detected from the soil layer just under the tephra layer which was accumulated around 9000 B.C.. Barnyard grass and Japanese millet are edible and closely related. So, these results suggest the possibility that the primitive cultivation of Japanese millet had begun in the early stage of Jyomon period.2.The situation in the early Jyomon periodA lot of Barnyard grass plant opals were detected in pottery sherds which derived from Sannaimaruyama site (Aomori prefecture). Considering the scale and the character of this site, there may be possibility that the cultivation of Japanese millet was done.3 .The situation in the last part of Jyomon periodRice plant opals were detected from pottery excavated from Okayama University premise site (Okayama prefecture) and Minamimizote site (Okayama prefecture). These potteries are estimated to have been made around 3500 B.P.. This result shows that rice cultivation already had begun in the western part of Japan in this period.And as a result of the investigation in Hietabaru site (Nagasaki prefecture), rice plant opals were detected from the soil layer just under the volcanic ash layer which was accumulated by Mutsuki pyroclastic flow glad around 3600 B.P..Considering the location of this site and the existence of other plant's remains, rice growing here possibly had been done at upland fields.