Abstract

Rice is the most important single crop in Japan, occupying 7-8 million acres which is 53 per cent of the total annual cultivated area of 15 million acres. The total production of rice is 10-4 million tons giving an average yield of 2,350 lb. (shelled rice) per nere. Due to the importance of rice in the national economy, great attention was given to rice improvement by the Government with the result that during the last 60 years, the area under rice has increased by about 25 per cent while the acre yields during the corresponding period increased by about 70 per cent. Thus the total production increased from 4.9 million tons during 1880 to 10-4 million tons during 1942, i.e. an increase of 113 per cent. It is due to the higher acre yields of rice and other crops that Japan is able to produce about 80 to 85 per cent of its food requirements for its population of 78 millions from the annual cultivated area of 15 million acres. The cultivated land of Japan consists mostly of coastal plains and narrow river valleys extending up into mountains. The diluvium is usually sandy and storile, uplands are leached and soils developed on volcanic parent material consisting of acidic lavas and ash are infertile. Thus the soils are generally poor in natural fertility, and soil fertility is apparently thus not a factor for higher acre yields. The high levels of production have been attained and are maintained mostly by the application of results of research in practical farming.

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