Average temperature of the winter season in Okinawa is not less than 15 degrees Celsius, and early shipment cultivation such as vegetables, fruits is possible. Institution fields increase year by year if they perform house cultivation, furthermore, to be able to hasten the time. On the other hand, the quality of clay soil that coral limestone and mudstone of Okinawa weathered is called a Jahgaru, and it is a characteristic that permeability and water retentivity are low. To make irrigation plan under such special climate and soil situation, an indoor experiment about soil physical properties and the spot observation about soil water movement at the root zone and soil water movement from the green house side were conducted. As a results, estimates of quantity of capillary rise was a little at Jahgaru soil. In the green house where ground water level is deep, the quantity of capillary supplying from the lower layer can be not expected too much, but the water supplying from the house side after the rain can be expected.
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