and Arai 1996). Therefore, cultivation techniques, such as
soil disinfection, the application of green mature crop and
fully fermented compost, soil improvement, disinfection of
seed tubers, and crop rotation with vegetables, are very
important in this upland soil.
(3) Environmental and cultural significance of Andosols
(1) Natural parks and Andosols
Among the 18 active volcanoes in the Tohoku region
(Fig. 6.2), 10 volcanoes and their surrounding areas
including Andosols are contained within National Parks: the
Hakkodasan, Towada, Hachimantai, Akita-Yakeyaka, Iwatesan, and Akita-Komagatake volcanoes are situated in the
Towada-Hachimantai National Park; the Azumayama,
Adatarayama, and Bandaisan volcanoes belong to the
Bandai-Asahi National Park; while Hiuchigatake volcano is
located in the Oze National Park. In addition, the areas of six
active volcanoes (Osorezan, Iwakisan, Chokaisan, Kurikomayama, Naruko, and Zaozan) are designated as
Quasi-National Parks. The unique morphology of volcanic
mountains and changes in vegetation according to elevation
create attractive landscapes.
(2) Ancient human activity and Andosol formation
It has been revealed that there is a close relationship between
the distribution of Jomon ruins (ca. 15,000–2300 years ago)
and the distribution of Melanic Andosols in Japan (Edamura
and Kumagai 2009). For example, in the Tohoku region,
many ruins of the early to late Jomon Period have been
discovered in areas of volcanic ash soils. It is thought that
the Jomon people resided in permanent settlements and
created a society in the volcanic areas with hunting and
fishing. Moreover, they might have practiced farming (Sato
et al. 2003a, b). Thus, Melanic Andosols are thought to have
been created under ecosystems largely influenced by human
beings (Hosono and Sase 2015). The Melanic Andosols
could be recognized as a soil containing important ruins.
6.2 Management of Paddy Soils
6.2.1 Organic Material Application
The effects of applying organic material to paddy rice (Oryza
sativa L) fields have been investigated at many agricultural
research centers in the Tohoku region. At the Tohoku
Agricultural Research Center, National Agriculture and
Food Research Organization (TARC, NARO, N39°29′,
E140°30′, altitude 30 m a.s.l.) located in Daisen, Akita
Prefecture, the effects of organic materials have been
examined in long-term field experiments with rice straw
compost (RSC) and livestock manure compost
(LMC) (Ohyama 1982; Ohyama et al. 1983; Sumida et al.
2002; Nishida et al. 2007). In one long-term field experiment
using RSC, compost was applied at the rate of 0, 1, 2, 3, or
4 kg m
−2 year
−1 from 1968. In all the treatments, N, P 2 O 5 ,
and K 2 O were applied at 8 g m
−2 as chemical fertilizer. In a
long-term field experiment using LMC, compost was applied
at the rate of 0 or 3.6 kg m
−2 year
−1 from 1973. The soil was
classified as fine-textured Gray Fluvic soil (Fluvisol).
Results from the relatively early period of these experiments
were reported by Ohyama (1982) and Ohyama et al. (1983).
In the long-term field experiment using RSC, the highest
yield was observed in the 2 kg m
−2 plot, which had a 10%
higher yield than the plot without RSC based on the average
yield for the 13 years following the initiation of the experiment. In the 3 and 4 kg m
−2 plots, the yields were lower
than those in the 1 and 2 kg m
−2 plots due to rank growth. In
the long-term field experiment using LMC, the beneficial
effect of the repeated application of LMC on rice yield was
clear in the plot with small amounts of chemical N fertilizer
application. In the plot with LMC and large amounts of
chemical N fertilizer application, however, yield decreased
due to the occurrence of rice blast. On the other hand, the
application of calcium silicate alleviated the rice blast in the
plot with the LMC and large amounts of chemical N fertilizer, resulting in higher rice yield than in the plot with LMC
without calcium silicate. Nitrogen supply to the rice plants
from the RSC gradually increased over time, averaging
1.0 g m
−2 for the 1 kg m
−2 application rate for the 13 years
following the initiation of the experiment. It was estimated
that 42.8% of the N in the RSC was retained in the soil,
14.7% of which was taken up by the rice plants, and 42.5%
of which was lost. The N supply to rice plants from LMC
was 1.1 g m
−2 for the 1 kg m
−2 application rate of LMC. It
was estimated that 48% of the N in the LMC was retained in
the soil, 23.6% of which was absorbed by the rice plant, and
28.4% of which was lost. It is noted that the rice plant
recovery of the N in the LMC increased by 4% following the
application of calcium silicate.
After the above investigations (Ohyama 1982; Ohyama
et al. 1983), when the effect of repeated compost application
had become stable, the nitrogen budgets of these long-term
field experiments was examined (Sumida et al. 2002). The N
balance in the plot without any N application indicated that
about 3–4 g m
−2 of N every year was supplied through irrigation water, wet and dry deposits, and biological fixation.
Chemical fertilizer N applied at 8 g m
−2 was scarcely
retained in the plow layer, and about 4 g m
−2 of that was
taken up by the rice plants, and about 4 g m
−2 was lost.
About 2 g m
−2 of N from RSC applied at 11 g N m
−2 was
194
H. Fujii et al.
soil disinfection, the application of green mature crop and
fully fermented compost, soil improvement, disinfection of
seed tubers, and crop rotation with vegetables, are very
important in this upland soil.
(3) Environmental and cultural significance of Andosols
(1) Natural parks and Andosols
Among the 18 active volcanoes in the Tohoku region
(Fig. 6.2), 10 volcanoes and their surrounding areas
including Andosols are contained within National Parks: the
Hakkodasan, Towada, Hachimantai, Akita-Yakeyaka, Iwatesan, and Akita-Komagatake volcanoes are situated in the
Towada-Hachimantai National Park; the Azumayama,
Adatarayama, and Bandaisan volcanoes belong to the
Bandai-Asahi National Park; while Hiuchigatake volcano is
located in the Oze National Park. In addition, the areas of six
active volcanoes (Osorezan, Iwakisan, Chokaisan, Kurikomayama, Naruko, and Zaozan) are designated as
Quasi-National Parks. The unique morphology of volcanic
mountains and changes in vegetation according to elevation
create attractive landscapes.
(2) Ancient human activity and Andosol formation
It has been revealed that there is a close relationship between
the distribution of Jomon ruins (ca. 15,000–2300 years ago)
and the distribution of Melanic Andosols in Japan (Edamura
and Kumagai 2009). For example, in the Tohoku region,
many ruins of the early to late Jomon Period have been
discovered in areas of volcanic ash soils. It is thought that
the Jomon people resided in permanent settlements and
created a society in the volcanic areas with hunting and
fishing. Moreover, they might have practiced farming (Sato
et al. 2003a, b). Thus, Melanic Andosols are thought to have
been created under ecosystems largely influenced by human
beings (Hosono and Sase 2015). The Melanic Andosols
could be recognized as a soil containing important ruins.
6.2 Management of Paddy Soils
6.2.1 Organic Material Application
The effects of applying organic material to paddy rice (Oryza
sativa L) fields have been investigated at many agricultural
research centers in the Tohoku region. At the Tohoku
Agricultural Research Center, National Agriculture and
Food Research Organization (TARC, NARO, N39°29′,
E140°30′, altitude 30 m a.s.l.) located in Daisen, Akita
Prefecture, the effects of organic materials have been
examined in long-term field experiments with rice straw
compost (RSC) and livestock manure compost
(LMC) (Ohyama 1982; Ohyama et al. 1983; Sumida et al.
2002; Nishida et al. 2007). In one long-term field experiment
using RSC, compost was applied at the rate of 0, 1, 2, 3, or
4 kg m
−2 year
−1 from 1968. In all the treatments, N, P 2 O 5 ,
and K 2 O were applied at 8 g m
−2 as chemical fertilizer. In a
long-term field experiment using LMC, compost was applied
at the rate of 0 or 3.6 kg m
−2 year
−1 from 1973. The soil was
classified as fine-textured Gray Fluvic soil (Fluvisol).
Results from the relatively early period of these experiments
were reported by Ohyama (1982) and Ohyama et al. (1983).
In the long-term field experiment using RSC, the highest
yield was observed in the 2 kg m
−2 plot, which had a 10%
higher yield than the plot without RSC based on the average
yield for the 13 years following the initiation of the experiment. In the 3 and 4 kg m
−2 plots, the yields were lower
than those in the 1 and 2 kg m
−2 plots due to rank growth. In
the long-term field experiment using LMC, the beneficial
effect of the repeated application of LMC on rice yield was
clear in the plot with small amounts of chemical N fertilizer
application. In the plot with LMC and large amounts of
chemical N fertilizer application, however, yield decreased
due to the occurrence of rice blast. On the other hand, the
application of calcium silicate alleviated the rice blast in the
plot with the LMC and large amounts of chemical N fertilizer, resulting in higher rice yield than in the plot with LMC
without calcium silicate. Nitrogen supply to the rice plants
from the RSC gradually increased over time, averaging
1.0 g m
−2 for the 1 kg m
−2 application rate for the 13 years
following the initiation of the experiment. It was estimated
that 42.8% of the N in the RSC was retained in the soil,
14.7% of which was taken up by the rice plants, and 42.5%
of which was lost. The N supply to rice plants from LMC
was 1.1 g m
−2 for the 1 kg m
−2 application rate of LMC. It
was estimated that 48% of the N in the LMC was retained in
the soil, 23.6% of which was absorbed by the rice plant, and
28.4% of which was lost. It is noted that the rice plant
recovery of the N in the LMC increased by 4% following the
application of calcium silicate.
After the above investigations (Ohyama 1982; Ohyama
et al. 1983), when the effect of repeated compost application
had become stable, the nitrogen budgets of these long-term
field experiments was examined (Sumida et al. 2002). The N
balance in the plot without any N application indicated that
about 3–4 g m
−2 of N every year was supplied through irrigation water, wet and dry deposits, and biological fixation.
Chemical fertilizer N applied at 8 g m
−2 was scarcely
retained in the plow layer, and about 4 g m
−2 of that was
taken up by the rice plants, and about 4 g m
−2 was lost.
About 2 g m
−2 of N from RSC applied at 11 g N m
−2 was
194
H. Fujii et al.