STATISTICAL RESEARCHES ON THE BAD HARVEST OF RICE IN JAPAN. : (1) On the Bad Harvest Type.

Abstract

From table 3 and figure 7 of the former report, the author considered that the regional appearance of the bad harvest year should be classified in three types as follows: I. North type belongs to the Hokkaido prefecture only and has the most severe bad harvest, and its trans-mode per cent is maximum, 15.9%. II. North-east type belongs to the northeast district in Japan and is the next severe bad harvest. This type has the width of about seventeen years period of bad harvest group and the length of about thirty years cyclic period. III. South-west type belongs to the southwest district in Japan, and probably having a longer cyclic period than the former type, but it difficult inferable about it for so short that the statistical period of this report is only a sixty years length. The correlative relationship between these three types is shown in figure 2. The most lowering injury to the rice production per unit area in Japan is that these three types of bad harvest fell into the same year, the average Ic is 79.3%. The next of lowering injury is the case combinate two types in each other I and II or I and III, the average Ic is 92.3% The single appearance of each three type is slighter decrease than the former, the average Ic is 94.3% as shown in table 3.