Abstract
The present study compared the current food production capacity of 14 major crops in Japan, and also estimated the potential ability for producing food for calories in all paddy fields and upland fields. The production of the 14 crops per capita per day on a calorie basis in Japan was 2497 kcal in 1961 and decreased to 795 kcal in 2010. This level was 26% of the world average, and 37% of the African average. Under the condition where all fields were used for 3 high yielding crops (rice, potato and sweetpotato) to increase the productivity, the production is estimated to increase toward 1626 kcal, but this is still 76% of the African average. Four scenarios were tested, i.e.,; agricultural land area will decrease and yield will not increase (scenario 1), agricultural land area will be kept at the present level but yield will not increase (scenario 2), agricultural land area will be kept at the present level and yield will increase (scenario 3), and the other conditions are the same as within scenario 1 but the population will not decrease (scenario 4). In 2030, the production was estimated to be 1608 kcal in scenario 1, 1826 kcal in scenario 2, 1926 kcal in scenario 3 and 1464 kcal in scenario 4. The present study suggested that agricultural land area needs to be maintained the current level at least, and the productivity per land area need to be improved for increasing food security.
