the mountainous backbone, the soil and the climate are
very different. The soil is widely distributed in fertile soil
based on tuff on the Japan Seaside. In the northern part of
the Pacific Ocean, volcanic ash soil (Andosols) is
distributed, and in the southern part, soil consisting of
granite is distributed. In the Tohoku region, while
overcoming cold and snow damage, paddy farming
centered on rice farming, livestock farming using rich
feed resources in the middle and mountain areas, resource
crops utilizing the cool climate, production of vegetables
and fruits, etc. A variety of agriculture has been
developed and played a role as a food supply base for
Japan. In the future, as agriculture becomes more
internationalized, people’s interest in the stable supply
of safe and secure food and environmental conservation
will be further heightened. Under such circumstances,
Tohoku agriculture is strongly required to switch to a
combined system combining field crops such as wheat,
soybeans, vegetables, flowers, etc. with livestock, and to
expand the scale of management, while putting rice
farming on a basic basis. The labor-saving and low-cost
production of high-quality, and high-value-added agricultural products that meet safety needs, stable production
of food by overcoming weather disasters, development of
natural circulation agriculture in harmony with the
environment, promotion of technology development that
responds to agriculture, etc. are being carried out.
Keywords
Andosols Á Paddy field Á Environmentally-friendly
agriculture Á Fluvic soils Á The great east Japan
earthquake
6.1 Outline of Soils in Tohoku
6.1.1 Soils in Tsuruoka City, Yamagata
Prefecture
Yamagata Prefecture is divided into four municipal areas:
Murayama, Mogami, Okitama, and Shonai. Of these, the
Shonai area has the largest area of arable land and paddy
fields and the highest rice yield (Ministry of Agriculture,
Forestry, and Fisheries [MAFF] 2015a, b). Paddy field
accounts for 90% of the arable land in the Shonai area
(MAFF 2015a, b). The Shonai area is surrounded by
mountains from the north, east, and south until the southwest, and is separated from the Sea of Japan by sand dunes
in the west, with a plain in the center.
Tsuruoka City is located in the south of the Shonai Plain,
a fluvial alluvial plain whose soils are derived from and
accumulated by rivers from the surrounding mountains
(Ariga 1984), including the Akagawa River system and the
Ohoyama River system. When we analyzed the clay mineral
composition of 35 paddy soils in Tsuruoka City, all soils
contained smectite as the main clay mineral and kaolin and
2:1–2:1:1 intergraded minerals. The mountains surrounding
the Shonai Plain are located in a green tuff region (Kitamura
1986). Green tuff contains a substantial amount of smectite
(Masui 1959a) and its sediment paddy soil is dominated by
smectite and kaolin mineral (Masui 1959b). Therefore, the
clay mineral composition of paddy soils in Tsuruoka City is
highly affected by green tuff from geological features distributed in the upper reaches of the Akagawa River system
and the Ohoyama River system.
Some paddy soils in Tsuruoka City contain chlorite.
These paddy soils were divided into three types based on
their chlorite content (Fig. 6.1). The soils free of chlorite are
distributed in the Ohoto River basin (Fig. 6.1a). The soils
containing small amounts of chlorite are distributed in the
Yazawa River basin and in a part of the Ohoto River basin
(Fig. 6.1b). The soils containing significant amounts of
chlorite are distributed in the Akagawa River, Yazawa River,
and Ohoyama River basins (Fig. 6.1c).
Granite of geological features is distributed in the upper
reaches of the Akagawa River and Yazawa River, but not in
the Ohoto River (Jinbo 1960). Thus, the chlorite weathered
from granite (Kanno et al. 1957) could be contained in the
paddy soil sediment following transport by the Akagawa
River and Yazawa River. The soil sediment deposited by the
Akagawa River may contain more materials derived from
granite than that deposited by the Yazawa River. The variation in the chlorite contents of different types of soil may
reflect the distribution of the flood basin of each river, that is,
the soils containing high levels of chlorite indicate the flood
basin of the Akagawa River, the soils containing lower
T. Saito
Hama Agricultural Regeneration Research Centre, Fukushima
Prefecture Agricultural Technology Centre, Soma City,
Fukushima Prefecture, Japan
T. Hirayama
Fukushima Prefecture Agricultural Technology Centre,
Fukushima Prefectural Government, Koriyama City, Fukushima
Prefecture, Japan
T. Katagiri
KONICA MINOLTA, INC., Tokyo, Japan
K. Ando
Yanmar HeliAgri CO., LTD, Osaka City, Osaka Prefecture, Japan
186
H. Fujii et al.
very different. The soil is widely distributed in fertile soil
based on tuff on the Japan Seaside. In the northern part of
the Pacific Ocean, volcanic ash soil (Andosols) is
distributed, and in the southern part, soil consisting of
granite is distributed. In the Tohoku region, while
overcoming cold and snow damage, paddy farming
centered on rice farming, livestock farming using rich
feed resources in the middle and mountain areas, resource
crops utilizing the cool climate, production of vegetables
and fruits, etc. A variety of agriculture has been
developed and played a role as a food supply base for
Japan. In the future, as agriculture becomes more
internationalized, people’s interest in the stable supply
of safe and secure food and environmental conservation
will be further heightened. Under such circumstances,
Tohoku agriculture is strongly required to switch to a
combined system combining field crops such as wheat,
soybeans, vegetables, flowers, etc. with livestock, and to
expand the scale of management, while putting rice
farming on a basic basis. The labor-saving and low-cost
production of high-quality, and high-value-added agricultural products that meet safety needs, stable production
of food by overcoming weather disasters, development of
natural circulation agriculture in harmony with the
environment, promotion of technology development that
responds to agriculture, etc. are being carried out.
Keywords
Andosols Á Paddy field Á Environmentally-friendly
agriculture Á Fluvic soils Á The great east Japan
earthquake
6.1 Outline of Soils in Tohoku
6.1.1 Soils in Tsuruoka City, Yamagata
Prefecture
Yamagata Prefecture is divided into four municipal areas:
Murayama, Mogami, Okitama, and Shonai. Of these, the
Shonai area has the largest area of arable land and paddy
fields and the highest rice yield (Ministry of Agriculture,
Forestry, and Fisheries [MAFF] 2015a, b). Paddy field
accounts for 90% of the arable land in the Shonai area
(MAFF 2015a, b). The Shonai area is surrounded by
mountains from the north, east, and south until the southwest, and is separated from the Sea of Japan by sand dunes
in the west, with a plain in the center.
Tsuruoka City is located in the south of the Shonai Plain,
a fluvial alluvial plain whose soils are derived from and
accumulated by rivers from the surrounding mountains
(Ariga 1984), including the Akagawa River system and the
Ohoyama River system. When we analyzed the clay mineral
composition of 35 paddy soils in Tsuruoka City, all soils
contained smectite as the main clay mineral and kaolin and
2:1–2:1:1 intergraded minerals. The mountains surrounding
the Shonai Plain are located in a green tuff region (Kitamura
1986). Green tuff contains a substantial amount of smectite
(Masui 1959a) and its sediment paddy soil is dominated by
smectite and kaolin mineral (Masui 1959b). Therefore, the
clay mineral composition of paddy soils in Tsuruoka City is
highly affected by green tuff from geological features distributed in the upper reaches of the Akagawa River system
and the Ohoyama River system.
Some paddy soils in Tsuruoka City contain chlorite.
These paddy soils were divided into three types based on
their chlorite content (Fig. 6.1). The soils free of chlorite are
distributed in the Ohoto River basin (Fig. 6.1a). The soils
containing small amounts of chlorite are distributed in the
Yazawa River basin and in a part of the Ohoto River basin
(Fig. 6.1b). The soils containing significant amounts of
chlorite are distributed in the Akagawa River, Yazawa River,
and Ohoyama River basins (Fig. 6.1c).
Granite of geological features is distributed in the upper
reaches of the Akagawa River and Yazawa River, but not in
the Ohoto River (Jinbo 1960). Thus, the chlorite weathered
from granite (Kanno et al. 1957) could be contained in the
paddy soil sediment following transport by the Akagawa
River and Yazawa River. The soil sediment deposited by the
Akagawa River may contain more materials derived from
granite than that deposited by the Yazawa River. The variation in the chlorite contents of different types of soil may
reflect the distribution of the flood basin of each river, that is,
the soils containing high levels of chlorite indicate the flood
basin of the Akagawa River, the soils containing lower
T. Saito
Hama Agricultural Regeneration Research Centre, Fukushima
Prefecture Agricultural Technology Centre, Soma City,
Fukushima Prefecture, Japan
T. Hirayama
Fukushima Prefecture Agricultural Technology Centre,
Fukushima Prefectural Government, Koriyama City, Fukushima
Prefecture, Japan
T. Katagiri
KONICA MINOLTA, INC., Tokyo, Japan
K. Ando
Yanmar HeliAgri CO., LTD, Osaka City, Osaka Prefecture, Japan
186
H. Fujii et al.