diverse sectors such as paddy rice, arable crops, vegetables,
and fruits. Okinawa, on the other hand, produces sugarcane,
pineapple, tropical fruits, and so on by taking advantage of
its subtropical climate. Moreover, large-scale livestock
production is active through both regions. Like other
regions of the globe, environmental issues related to modern
agriculture are challenges, including nitrate contamination
of groundwater, greenhouse gas emission, soil erosion, and
so on. Beside dominating modern agriculture, traditional
agriculture with thought-provoking soil management practices still survives in these regions.
Keywords
Kyushu–Okinawa Á Andosols Á Red-Yellow soils Á
Large-scale livestock production Á
Environmental-friendly agriculture
10.1 Outline of Soils in Kyushu and Okinawa
Regions
10.1.1 Soil-Forming Factors
The Kyushu–Okinawa region is located in the southwest of
the Japanese Islands and consists of Kyushu, islands around
Kyushu including Tsushima Island, the Goto Islands, the
Amakusa Islands, the Koshikijima Islands, and the Nansei
Islands (Figs. 10.1 and 10.2). The region is extensive,
ranging from 123 to 132° E (a distance of 850 km) in the
east–west direction and from 24 to 35° N (1200 km) in the
north–south direction. Although the climate of the Kyushu
region is mild as a whole under the influences of the Japan
Current and the Tsushima Current, it is further subdivided
into several climatic zones due to influences such as those
from mountains. Additionally, subtropical regions are distributed in the Nansei Islands. The Kyushu region is located
at the junction between the Southwest Japan Arc and the
Ryukyu Arc. Volcanoes such as Mt. Aso and Mt. Unzen are
located in central Kyushu, and the volcanic line consisting of
Mt. Kirishima, Mt. Sakurajima, and Iwo Jima is distributed
from the southern part of Kyushu to the Nansei Islands.
Generally, climate, vegetation, geology (parent material)
and topography greatly influence soil formation. Various soil
types are generated depending on the type and intensity of
soil-forming factors. For example, one of the soil types that
strongly indicates the effects of climate and vegetation is
Red-Yellow soil, a weathered soil type with less accumulation of organic matter and low base saturation. In the
Kyushu–Okinawa region, Red-Yellow soils are widely distributed in the hilly low mountain area of the Nansei Islands.
On the other hand, one type of soil that is strongly affected
by geology (parent material) is Andosols. This soil type,
derived from volcanic ejecta, is distributed around the volcanoes in the wet subtropical monsoon region from the
southern subarctic. In the Kyushu–Okinawa region, this soil
is widely distributed in the central and southern part of
Kyushu. Holocene fluvial and marine sediments are deposited in the plains around the Ariake Sea. Fluvic soils are
distributed in such areas.
1. Climate and vegetation
According to the climate classification using the Warmth Index
suggested by Kira (1971), the climate of the Kyushu–Okinawa
region is classified into the following four climate zones: the
cool temperate zone, warm temperate zone, subtropical zone
and Setouchi climate zone (Nakamura et al. 1996). The annual
average temperature and annual precipitation in each climate
zone were cited from a finer climate classification by Ohba
(2004). According to the soil temperature regime map by
Takata et al. (2011), the cool temperate zone, the warm temperate zone, the subtropical zone, and the Setouchi climate
zone almost correspond to the mesic or thermic soil temperature regime, the thermic soil temperature regime, the hyperthermic soil temperature regime, and the thermic soil
temperature regime, respectively.
(1) Cool temperate zone
The annual average temperature, annual precipitation, and
average temperature in January are 15 °C or less, about
2000 mm or more, and 5 °C or less, respectively. This climate zone includes the mountainous area in central Kyushu.
Deciduous broad-leaved trees, mainly Japanese beech (Fagus
crenata) and shiraki (Neoshirakia japonica), are distributed.
Evergreen coniferous trees, mainly Japanese fir (Abies firma)
and southern Japanese hemlock (Tsuga sieboldii), are distributed in the transition area with the warm temperate zone.
(2) Warm temperate zone
The annual average temperature, annual precipitation, and
average temperature in January are 15–17 °C, about 1600–
I. Akagi
Faculty of Agriculture, Kagoshima University, Kagoshima City,
Kagoshima Prefecture, Japan
K. Kinjo
Faculty of Agriculture, University of Ryukyus, Nishihara Town,
Okinawa Prefecture, Japan
K. Mitsugi
Kumamoto Prefectural Agricultural Research Center, Kumamoto
Prefectural Government, Koshi City, Kumamoto Prefecture, Japan
328
Y. Arakawa et al.
and fruits. Okinawa, on the other hand, produces sugarcane,
pineapple, tropical fruits, and so on by taking advantage of
its subtropical climate. Moreover, large-scale livestock
production is active through both regions. Like other
regions of the globe, environmental issues related to modern
agriculture are challenges, including nitrate contamination
of groundwater, greenhouse gas emission, soil erosion, and
so on. Beside dominating modern agriculture, traditional
agriculture with thought-provoking soil management practices still survives in these regions.
Keywords
Kyushu–Okinawa Á Andosols Á Red-Yellow soils Á
Large-scale livestock production Á
Environmental-friendly agriculture
10.1 Outline of Soils in Kyushu and Okinawa
Regions
10.1.1 Soil-Forming Factors
The Kyushu–Okinawa region is located in the southwest of
the Japanese Islands and consists of Kyushu, islands around
Kyushu including Tsushima Island, the Goto Islands, the
Amakusa Islands, the Koshikijima Islands, and the Nansei
Islands (Figs. 10.1 and 10.2). The region is extensive,
ranging from 123 to 132° E (a distance of 850 km) in the
east–west direction and from 24 to 35° N (1200 km) in the
north–south direction. Although the climate of the Kyushu
region is mild as a whole under the influences of the Japan
Current and the Tsushima Current, it is further subdivided
into several climatic zones due to influences such as those
from mountains. Additionally, subtropical regions are distributed in the Nansei Islands. The Kyushu region is located
at the junction between the Southwest Japan Arc and the
Ryukyu Arc. Volcanoes such as Mt. Aso and Mt. Unzen are
located in central Kyushu, and the volcanic line consisting of
Mt. Kirishima, Mt. Sakurajima, and Iwo Jima is distributed
from the southern part of Kyushu to the Nansei Islands.
Generally, climate, vegetation, geology (parent material)
and topography greatly influence soil formation. Various soil
types are generated depending on the type and intensity of
soil-forming factors. For example, one of the soil types that
strongly indicates the effects of climate and vegetation is
Red-Yellow soil, a weathered soil type with less accumulation of organic matter and low base saturation. In the
Kyushu–Okinawa region, Red-Yellow soils are widely distributed in the hilly low mountain area of the Nansei Islands.
On the other hand, one type of soil that is strongly affected
by geology (parent material) is Andosols. This soil type,
derived from volcanic ejecta, is distributed around the volcanoes in the wet subtropical monsoon region from the
southern subarctic. In the Kyushu–Okinawa region, this soil
is widely distributed in the central and southern part of
Kyushu. Holocene fluvial and marine sediments are deposited in the plains around the Ariake Sea. Fluvic soils are
distributed in such areas.
1. Climate and vegetation
According to the climate classification using the Warmth Index
suggested by Kira (1971), the climate of the Kyushu–Okinawa
region is classified into the following four climate zones: the
cool temperate zone, warm temperate zone, subtropical zone
and Setouchi climate zone (Nakamura et al. 1996). The annual
average temperature and annual precipitation in each climate
zone were cited from a finer climate classification by Ohba
(2004). According to the soil temperature regime map by
Takata et al. (2011), the cool temperate zone, the warm temperate zone, the subtropical zone, and the Setouchi climate
zone almost correspond to the mesic or thermic soil temperature regime, the thermic soil temperature regime, the hyperthermic soil temperature regime, and the thermic soil
temperature regime, respectively.
(1) Cool temperate zone
The annual average temperature, annual precipitation, and
average temperature in January are 15 °C or less, about
2000 mm or more, and 5 °C or less, respectively. This climate zone includes the mountainous area in central Kyushu.
Deciduous broad-leaved trees, mainly Japanese beech (Fagus
crenata) and shiraki (Neoshirakia japonica), are distributed.
Evergreen coniferous trees, mainly Japanese fir (Abies firma)
and southern Japanese hemlock (Tsuga sieboldii), are distributed in the transition area with the warm temperate zone.
(2) Warm temperate zone
The annual average temperature, annual precipitation, and
average temperature in January are 15–17 °C, about 1600–
I. Akagi
Faculty of Agriculture, Kagoshima University, Kagoshima City,
Kagoshima Prefecture, Japan
K. Kinjo
Faculty of Agriculture, University of Ryukyus, Nishihara Town,
Okinawa Prefecture, Japan
K. Mitsugi
Kumamoto Prefectural Agricultural Research Center, Kumamoto
Prefectural Government, Koshi City, Kumamoto Prefecture, Japan
328
Y. Arakawa et al.