On the Records of Paddy Rice Yield from 1865 to 1948 by a Farmer, Akio MIZUSHIMA in Okayama Prefectrue

[摘要] 1. The author investigated the records of paddy rice harvest by Mr. Akio MIZUSHiMA, an old farmer resident in Okayama Prefecture, written by him and his ancestors from 1865 to 1948 continuously. 2. From the data presented in the manuscripts, it was demonstrated very clearly that the rice yields at his fields had not only been kept higher than the average of the contry but also been improved year by year steadily by the owners through that period. The author made statistical calculations on the data and obtained the following formulae showing relations betwen the year (x) and the yield (y-kokw) of rough rice per tan, at three fields of his own. [table]

[学科分类] 农业科学（综合）