|Budget Amount *help
¥1,700,000 (Direct Cost : ¥1,700,000)
Fiscal Year 1993 : ¥400,000 (Direct Cost : ¥400,000)
Fiscal Year 1992 : ¥1,300,000 (Direct Cost : ¥1,300,000)
With a view of obtaining basic data mecessary for making a future plan of irrigation, land improvement project and reclamation of an orchard, the actual conditions of root development, soil moisture fluctuation, ground-water level and soil moisture balance by the tank model method in an orchard (Pear, Grape, Cherry and Persimmon) surrounded with the paddy field, were investigated from 1990 to 1993. The results obtained are as follows. 1. The roots of grape, pear and persimmon were found in the top 30 cm layr from about 93 % to about 99 % of the total root weight. 2. Soil moisture suction at a depth of 10 cm, 20 cm, 30 cm, 50 cm and 70 cm in an orchard rose during the day and decreased gradually during the night. It is considered that these fluctuations are directly related to the depth distribution of roots which absorb water at each depth. 3. The top-root ratio of deciduous fruit trees was 1.6-1.7 (grape), 1.4-2.0 (persimmon) and 2.7-3.1 (pear) respectively. 4. The irrigation facilities for irrigation in a pear orchard is necessary. 5. The estimation of soil moisture balance in the persimmon orchard was made by means of the tank model method as well as the water balance method.