@article{oai:repository.naro.go.jp:00001613,
 author = {井出, 保行 and IDE, Yasuyuki and 小山, 信明 and KOYAMA, Nobuaki and 佐藤, 節郎 and SATO, Setsuro and 高橋, 佳孝 and TAKAHASHI , Yoshitaka},
 journal = {近畿中国四国農業研究センター研究報告, BULLETIN of THE NATIONAL AGRICULTURAL RESEARCH CENTER for WESTERN REGION},
 month = {Mar},
 note = {The majority of agricultural fields in the Chugoku District and the Shikoku District located on the southwestern part of Japan are distributed in hilly and mountainous areas. In those districts, the number of abandoned terrace paddy fields has rapidly increased since farmers have ceased their agricultural production, owing both to price depreciation of their products and to disadvantageous conditions for cultivation. The expansion of these abandoned fields has caused serious problems in agriculture, i.e., deterioration of rural landscapes, damage to field crops by wild animals that inhabit the shrub areas, and so on. The management of abandoned terrace paddy fields by means of cattle grazing is evaluated as a practical means for preserving agricultural resources. In this study, we examined the slope maintenance method in the abandoned terrace paddy field under the grazing condition. Experiments were carried out in a abandoned terrace paddy field (200m above sea level), located in the middle of the Shimane Prefecture in southwestern Japan (35°12′North latitude and 132°34′East longitude). The mean annual temperature and precipitation was 16.0℃ and 1,770mm, respectively, as recorded at a meteorological station located 7 km northeast of the study site, at 15m above sea level. The experimental field was 7,149m^2 in size, and ten abandoned rice fields (total area 2,228m^2) exist in the field. Cattle grazing was started in 1996. The number of grazing cattle was 1,300 head / ha / year in 1996, then it decreased to 650 head / ha / year after 1997. The reason for the decrease in the number of grazing cattle is that the vegetation in the field deteriorated rapidly. The result obtained were as follows : 1 Most of the bare areas occurred in places where the position of the fence was improper. Especially, a large bare area was produced in a place where the fence was located on the upper edge of the slope. It was thought that the creation of bare areas caused by the fence could be avoided by improving the position of the fence. 2 In southwestern Japan, many of the slopes in the terrace paddy field are covered by the vegetation of Miscanthus-type. Japanese plume-grass (Miscanthus sinensis Anderss.) which is dominant species on the slope declines promptly under cattle grazing. The reason for this decline is that this species has little grazing tolerance. Additionally, it was thought that grass shortage on the rice field which was caused by poor drainage and high dung concentration had accelerated the decline of the Japanese plume-grass by increasing the degree of defoliation on the slope. The amount of bare area expanded rapidly when the Japanese plume-grass declined because the soil fertility is very low on the slope. Therefore, when the slope vegetation was the Miscanthustype, it was necessary to shift the vegetation to the type which has both grazing tolerance and infertility tolerance. 3 Cattle track are necessary to maintain the slope under grazing conditions. The number of the cattle tracks formed on the slope can be determined by the following expression. Number of the cattle track ≒ Slope height (cm) ÷ 120 -1 Raise the decimals to a unit. It is also necessary to consider the following in regard to the formation of the cattle tracks on the slope : 1) Obstacles such as shrubs on the slope are to be removed. 2) The grazing number and the grazing season (especially, winter) are noted respectively. 4 Under the grazing condition, the grass species introduced into the slope should have the following characteristics : 1) Tolerance to grazing and tramping. 2) Tolerance to low soil nutrients. 3) High soil retentivity. 4) Not becoming a weed in other rice fields under cultivation. 5) Its seed or sod can be easily obtained. Japanese lawngrass (Zoysia japonica Steud.) and centipedegrass (Eremochloa ophiuroides (Munro) Hack.) were considered grass species that met these requirements in southwestern Japan. The method of planting the grass grown in a φ9 cm pot was effective in establishing these grass species as slope vegetation. 5 The method of bonding the sod (30cm×18cm) of Japanese lawngrass using fresh feces was effective for the restoration of a large bare areas.},
 pages = {15--36},
 title = {放牧導入による棚田跡地の保全的利用},
 volume = {3},
 year = {2004},
 yomi = {イデ, ヤスユキ and コヤマ, ノブアキ and サトウ, セツロウ and タカハシ, ヨシタカ}
}