1952 Volume 20 Issue 3-4 Pages 181-186
1. Erosion survey of apple orchards was practiced on the Kashiwagi Hill, Yamagata Village, Minami-tsugaru-County, Aomori Prefecture, during from November, 1950 to March, 1951
2. This hill which lies a part of the sloping apple orchards in Minamitsugaru-County, has 272 acres of land, of which about 200 acres are occupied by orchards. The first apple trees on this hill were planted during 1909 to 1913 after land clearing. From the geological point of view, soils of this hill are volcanic detritus; and from the soil type are classified into two kinds-ando soils and brown podosolic soils. About 80 per cent of the slope, 100 to 200 meters in length, is at an angle of 8 to 25 degrees.
3. The results of. erosion survey are shown in a map. About 32 per cent of total area of the Kashiwagi Hill exclusive farm road was subject to moderate or moderately severe sheet erosion; and 38.4 per cent of it to severe sheet erosion. The approximate acreage and percentage of each erosion condition in apple orchards are given in the following table.