傾斜地かんきつ園の造成に関する研究

I. 造園形態と造成限界

抄録

1) This study was carried out in order to examine the characteristics of forms and limitation of reclamation of a citrus orchard on slope land.
2) Three forms of reclamation of orchards investigated were as follows: I. horizontal terraced field. II. sloped terraced field with a wide oblique section. III. sloped field.
Items of the reclamation for these forms were an original sloping angle of 8°-30°, sloping face of a terraced field of 45°-80°and sloping face of a sloped field of 45°-55°. From these conditions, the author extracted the generalization of the data.
3) To clarify the characteristics of the forms of reclamation, the author investigated the following factors: precentage of reclamation of fields, the function of field surfaces and limiting factors of excution, excution by a bulldozer, quantity of soil originated in excution, and ecology and methods of management of a citrus orchard. The author examined the suitability for citrus management on each item.
4) From the view-point of characteristics of the forms of reclamation on slope land, the sloped field ranked as the best, which was followed by the sloped terraced field with a wide oblique section, and the horizontal terraced field showed many problems.
5) The limiting angle of reclamation of orchards on slope land was 20° at the horizontal terraced field and the sloped terraced field with a wide oblique section, and the sloped field showed from 20° to 25° in the original slope.
6) From the characteristics of forms of reclamation, the above mentioned items are the limit of reclamation. But hereinafter, for the modernized citrus orchard, rational land utilization, reasonable planning of arrangement of equipment, planning of settlements of accounts, etc, must be discussed and brought into practice.