T. Takakura
In Japanese agriculture, protected cultivation has been one of the most promising fields for young people inheriting farms because of its high and stable income. You will realize this by the fact that almost 50% of greenhouse growers earn their living only from greenhouse products; on the other hand, the corresponding figure for rice growers is less than 10%, even though the rice price is heavily protected by the government. Therefore, you can say that energy cost and supply is the only problem in protected cultivation.

The consumption of oil in Japanese agriculture is more or less similar to that of the United States and other countries and is about 3% of the total. But the pressure from heavy industry on the allocation plan allowed no increase in oil supply to protected cultivation in the last year. The area under cover is still increasing at the rate of 5 to 7%/year on the average (more than 20% for fruit trees - oranges, apples, grapes), but most growers are developing better insulation techniques. Some growers added one or two layers of thermal screens in addition to the existing one layer.

Takakura, T. (1981). FUTURE OUTLOOK AND RESEARCH NEEDS. Acta Hortic. 115, 715-716
DOI: 10.17660/ActaHortic.1981.115.83

Acta Horticulturae