Cultivation of field crops
Kazuto Iwama
Laboratory of Crop Science
Research Faculty of Agriculture
Hokkaido University
Email:iwama@res.agr.hokudai.ac.jp

Chapter 2
Cultivation of Field Crops

Kazuto Iwama
1. History(1) Until the middle of 19th century
In ancient days, local peoples called “Ainu” lived in Hokkaido. They originallycame from the northern parts of Asia, such as Siberia and Karafuto, and they
were mainly dependent on hunting. In the 16th century, so called “Japanese”
governed by Tokugawa Shogun regime immigrated to the southern part of
Hokkaido (Fig. 2-1), Matsumae, and established the domain of Matsumae. They
used to export natural products such as seaweeds “Konbu” (Fig. 2-2), fishes andanimal skins produced by local people of Hokkaido, and imported rice for staple
food from main islands of Japan. Some fishermen and merchants, who generally
visited coastal areas of Hokkaido during the summer, also used to cultivate
vegetables in a small area near their residences. Although they wanted tocultivate rice, the cultivars introduced from the main islands did not grow well in
Hokkaido because of cold climate.
In the 18th century, some foreigners mainly Russians used to visit someports of Hokkaido, e.g. Hakodate and Kushiro (Fig. 2-1), and bought water andsome vegetables. Potato was their favorite vegetable. As a result its cultivation
increased in areas near the ports. A historical book written in the mid 19th
century in Hakodate, reported more than 100 ha under potato cultivation in
Hokkaido. Russians also introduced some potato cultivars to Hokkaido, e.g.
‘Kushiro-murasaki’, which is different from the present-day potato cultivars.
(2) Establishment of Meiji government
In the mid 19th century, the Tokugawa Shogun regime collapsed and the Meiji
government governed throughout Japan including Hokkaido. The Meiji
government established the Hokkaido Development Office, “Kaitakushi”, in2-1

◎WAKKANAIAbashiri

Kamikawa
Sorachi◎
ASAHIKAWA

Ishikari◎ABASHIRI◎KUSHIRO◎SAPPORO◎OBIHIRO

Tokachi◎HAKODATE◎MATSUMAE
Fig. 2-1. Map of Hokkaido.

Arrows; district name , Double circles; city name.

Fig. 2-2. Seaweeds “Konbu”

Fig. 2-3.

exported to main islands of Japan.

(Historical Village of Hokkaido)

2-2

Central office of “Kaitakushi”.

Hokkaido and set up its central office in Sapporo in 1869 (Fig. 2-3). The“Kaitakushi” enhanced immigration from main islands of Japan to Hokkaido; thus
the population of Hokkaido increased rapidly (Table 2-1). From 1869 to 1936,
about 3 million people immigrated to Hokkaido, and half of them were farmers.
Some immigrants were called “Tondenhei”, meaning the soldier for protection
and cultivation of land (Table 2-2, Fig. 2-4). “Tondenhei” were mainly warriors(“Samurai”) of defeated Tokugawa Shogun regime of Tohoku and Hokuriku
areas of Honshu Island (Fig. 2-4). Some villages and cities of Hokkaido werenamed based on the places of origin of the immigrants in Japan.
“Kaitakushi” founded Sapporo Agricultural College (presently a part of
Hokkaido University) in 1876, and invited professors from abroad, mainly from
USA. The most famous professor was Dr. William Smith Clark, a former
president of Massachusetts Agricultural College in USA. In 1878, he became thefirst vice-president of Sapporo Agricultural College, and inculcated a frontier
spirit in young students coming from main islands of Japan. His words "Boys Be
Ambitious", to the students when he left the college, became famous and show afrontier spirit. The students educated at Sapporo Agricultural College became
leaders of Japan not only in agriculture but also in many other fields of higheducation and western thought. A few examples are Dr. Inazou Nitobe(pedagogy and economics), Mr. Kanzou Uchimura (philosophy and religion) and
Mr. Takeo Arishima (literature).
(3) The spread of rice cultivation
The invited foreign professors studied the land and the climate of Hokkaido.
They recommended an agriculture system similar to the North America, i.e.
cultivation of upland field crops such as wheat and potato, and dairy farming.
They considered that rice cultivation was not suitable for Hokkaido because of
too cool climate. However, most of the immigrants from main islands of Japan
did not like to change to a crop other than rice as a staple food. In addition, rice
culms could also be used to produce winter snowshoes and ropes (Fig. 2-5).
Because of the strong demand for rice by the immigrants including merchants
and industry people, the market price of rice in Hokkaido was much higher thanof other cereals. Therefore, farmers continued trials with rice cultivation. In 1873,

2-3

Table 2-1. Population in Hokkaido.
Year
Japan Hokkaido Ratio Note
(million) (million) (%)
1600
12
0.01
0.08
1)
1721
31
0.02
0.06
1850
0.08
2)
1873
34
0.12
0.36
1884
37
0.23
0.61
1903
47
0.99
2.13
1918
56
2.05
3.68
3)
1930
64
2.81
4.36
1940
72
3.23
4.49
1950
83
4.30
5.16
1960
93
5.04
5.39
1970
104
5.18
5.00
1980
117
5.58
4.76
1990
124
5.64
4.57
1997
126
5.70
4.52
4)
2000
127
5.68
4.48
1)The start of Tokugawa shogun regime.
2) The end of Tokugawa shogun regime.
The Meiji government started in 1867.
3) Fifty years since Kaitakushi opening.
4) The maximum population in Hokkaido.

Table 2-2. Cultivating area of field
crops in Hokkaido (1000ha).
Total Rice
Upland
Year
%
crops
1882
20
1894
38
3
8
35
1900 10399941910 224
35 16
189
1918 387
67 17
321
1919 402
73 18
329
1920 380
81 21
299
1930 473 187 40
2861940 530 181 34349
1950 402 144 36
2581960 554 197 36357
1967 539 247 46
293
1968 532 259 49
274
1969 531 266 50
2651970 463 206 45
257
1980 445 154 35
290
1990 480 146 30
334
2000 424 135 32
289

Fig. 2-4. Clearing of forests land (topleft figure), a village of “Tondenhei”(top right figure), and a farmhouse of
Iwama family immigrated from Sendai
district (left figure).
(Historical Village of Hokkaido)

2-4

Mr. Kyuzo Nakayama, an immigrant from Tohoku area and manager of a horse
station at Shimamatsu near Sapporo, succeeded in selecting from theintroduced cultivars of Tohoku area a rice cultivar ‘Akage’, which was tolerant tocool weather (Fig. 2-5).
In 1892, Mr. Tuneaki Sako, head of the financial division in “Kaitakushi”,
decided to enhance rice cultivation in Hokkaido and provided financial support
for this. In 1886, “Kaitakushi” also established agricultural experiment stations
throughout Hokkaido, and rice breeding was officially started. The breeders at
the experimental stations initially practiced selection in cultivars introduced fromthe main islands of Japan, mostly from Tohoku area. In 1915, they started a pureline selection program to produce genetic purity for superior characteristics.
The breeding by making crosses between the selected cultivars was started in
1913, just after the discovery of Mendelian laws by H. de Vries et al. in 1900.
Using these methods, superior cultivars with high tolerance to cool climate andpests, and having high yield and adaptability to Hokkaido’s climate were
progressively developed. As a result, rice cultivation rapidly increased
throughout Hokkaido, and in 1930 it reached to about 200,000 ha with a total
production of 432,000 ton and per capita availability of 150 kg, which was
equivalent to per capita average of Japan (Table 2-3).
(4) The cultivation of upland field crops
In the northern and eastern parts of Hokkaido, i.e. Kitami, Abashiri and Tokachi(Fig. 2-1), rice cultivation could not be established because of very cool climate.
Here, however, some upland crops such as potato and wheat achieved higher
yield than in the main islands of Japan (Table 2-4).
In the early 20th century, Baron (“Danshaku” in Japanese) Kawata, presidentof a ship building company in Hakodate, imported many potato cultivars from
Europe and USA to examine their adaptability in his experimental field near
Hakodate. Among these, ‘Irish Cobbler’ bred in 1876 in USA, proved to be an
early bulking and high yielding cultivar with good culinary quality. It was rapidly
adopted by the farmers near his experimental field, who named it‘Danshaku-imo’ (Baron potato, Fig. 2-6). Official potato breeding also started in
the early 20th century at the Hokkaido Agricultural Experiment Station. Cultivar

2-5

Fig.

2-5.

Memorial

rice

field

at

Shimamatsu (top figure), where Mr. Kyuzou
Nakayama succeeded in selecting a ricecultivar ‘Akage’, and some products (matand snowshoes) from rice straw (leftfigure).

Table 2-3. Rice cultivation in Japan and Hokkaido.
Japan
Hokkaido
Note
Year
Area
Yield Production
Area Yield Production(1000ha) (t/ha) (1000t/ha) (1000ha) (t/ha) (1000t/ha) (%)
1887
1.8 1.74
3
1890
1.9 2.895
18942664 2.346236
3.2 2.55
8 0.1
1900
2731 2.24
6122
9.1 1.97
18 0.31910
2834 2.42
6855
34.8 2.12
74 1.1
1920
2960 3.11
9205
81.2 2.00
178 1.9
19303079 3.18
9790
186.8 2.31
432 4.4
19403004 2.98
8955
181.3 1.62
293 3.3
1950
2877 3.27
9412
143.6 3.27
470 5.0
1960
3124 4.01
12539
197.1 4.01
790 6.3
19673149 4.53
14257
246.6 4.52
1114 7.8 1)
19683171 4.49
14223
258.6 4.74
1227 8.6 2)
19693173 4.35
13797
266.2 3.51
934 6.8 3)
19702836 4.42
12528
206.4 4.43
914 7.3 4)
19802350 4.12
9692
154.2 3.85
594 6.1
19842290 5.17
11832
154.7 5.51
853 7.2
1990
2055 5.09
10463
146.3 5.40
790 7.5
2000
1763 5.37
9472
134.9 5.40
729 7.7
1) The maximum production in Japan. 2) The maximum production in Hokkaudo.
3) The maximum cultivation area in Japan and Hokkaido.
4) The start of the policy for reducing rice cultivation.

2-6

‘Benimaru’ with high starch yield, and cultivar ‘Norin 1’ having high yield andresistance to late blight disease were released in 1937 and 1943, respectively(Fig. 2-6). These and cultivar ‘May Queen’ introduced in 1908 from UK were
widely cultivated not only in Hokkaido but also in the other parts of Japan, andare still sharing about 50% of total potato area in Japan.
In the main islands of Japan, wheat is generally cultivated after harvesting
rice. While in Hokkaido, it is cultivated mainly in upland fields, from September toAugust as winter wheat and from April to August as spring wheat. Since climate
for the wheat cultivation in Hokkaido is different from that in other areas of Japan,
many cultivars were introduced from Europe and North America to examine theiradaptability in Hokkaido. In the early 20th century, a number of letters requesting
seeds of wheat cultivars were written by Dr. Takajirou Minami, the first professorof Crop Science Laboratory in Hokkaido University. Official breeding of wheat
was started in 1920 at the Hokkaido Agricultural Experiment Station, and many
cultivars from crosses among imported cultivars were released. Cultivar‘Akasabi-shirazu’ bred in 1927 was highly tolerant to red rust disease and wascultivated throughout Hokkaido. Cultivar ‘Norin 35’ bred in 1938 had hard grain
and was thus suitable for bread making. Cultivar ‘Hokuei’ bred in 1954 had avery short culm and thus high tolerance to lodging. This enabled the use a large
amount of chemical fertilizers and dense planting, resulting in a rapid increase inyield from 2.4-3.0 ton/ha to 4.2-4.8 ton/ha at the experimental level.
Hokkaido became a leading producer of several other crops also. Flax had
been cultivated in Hokkaido in the late 19th century and exported to foreigncountries as a raw material for fiber production. About two third of peppermint of
the world was produced in Kitami area in the early 20th century. Althoughpeppermint and flax are not cultivated now, farmers and related industries hadearned a lot from their cultivation and this contributed for the progress of
Hokkaido agriculture.
2. Present status
The area under field crops in Hokkaido is 640,000 ha, which is 13% of total area
under field crops in Japan (Table 2-5). The number of farmers in Hokkaido is
52,000, about 3% of total number of farmers in Japan (Table 2-6). Thus the

2-7Table 2-4. Cultivating area and yield of potato and wheat in Japan and Hokkaido.
PotatoWheat
Japan
Hokkaido
Japan
Hokkaido
Year
Area
Yield
Area
Yield
Area
Yield
Area
Yield
(1000ha) (t/ha)(1000ha) (t/ha)(1000ha) (t/ha)(1000ha) (t/ha)
1887
16.4
6.5
2.3
9.9
387.2 1.08
1897
28.6
7.6
10.2 10.7
454.4 1.15
1.9 1.43
1907
58.3
9.5
23.8 10.9
440.3 1.38
10.1 1.36
1916
102.7 10.2
57.9 11.0
527.6 1.53
16.5 1.23
1926
96.6
8.9
45.0
8.2
463.7 1.74
9.1 1.43
1930
103.0 10.1
45.2
9.4
487.4 1.72
13.5 1.62
1940
166.0
9.9
83.5
9.5
834.2 2.15
34.2 1.28
1950
192.4 12.7
75.5 15.1
763.5 1.75
29.8 1.32
1960
204.3 17.6
89.3 20.2
602.3 2.54
15.0 2.07
1970
158.8 22.7
69.8 31.0
229.2 2.07
11.7 1.03
1980
123.4 27.7
64.7 37.4
191.1 3.05
87.6 3.21
1990
115.8 30.7
67.5 38.5
260.4 3.65
120.9 4.14
2000
94.6 30.6
59.1 36.6
183.0 3.76
103.2 3.66

Fig. 2-6.

Display of potato varieties cultivated in Hokkaido.

‘Irish Cobbler’; left side of top row, ‘May Queen’; right side of second row,
‘Benimaru’; left side of third row, ‘Norin 1’; left side of bottom row.
(National Agricultural Research Center for Hokkaido Region)

2-8

average farm size in Hokkaido is about 20 ha, which is more than 10 times theaverage farm size in Japan, and almost equivalent to that in many European
countries. Hokkaido is the top producer of both rice and many field crops inJapan. Mechanization has enhanced the efficiency of crop production. The
status of each field crop in Hokkaido is explained in the following sections.
(1) Rice
Rice is cultivated on 119,000 ha of irrigated paddy fields in Hokkaido (Fig. 2-7),
which is about 7% that of Japan (Table 2-7). In Hokkaido, rice is cultivatedmainly in the central parts, i.e. Ishikari, Sorachi and Kamikawa (Fig. 2-1).
Although Hokkaido is one of the most northern areas of the world cultivating rice,
yet the yield level is high. Hulled grain yield in Hokkaido is 5.7 ton/ha, while theJapanese average is 5.3 ton/ha and the world average is about 2.5 ton/ha (Table
2-7). Presently, Hokkaido is the top producer of rice in Japan, contributing 8% of
the total production.
Hokkaido has achieved an outstanding position in rice production as a resultof continuous efforts for a long period since the Meiji period. By breeding
improved cultivars and improving the cultivation methods, tolerance to cool
weather has been enhanced (Fig. 2-8). Present-day rice cultivars of Hokkaido
have much higher tolerance to cool weather than the old ones. In 1993, theunusual cool weather of Hokkaido caused a severe damage to rice growth, andthe average yield was only 40% of the mean of previous five years. However, thereduction in yield was much smaller in the present-day cultivars than in the oldones (Fig. 2-9). Keeping in view the weather forecasts from agriculturalextension centers, many farmers practiced water blanket method to maintainhigh level of water in fields and this protected young panicles containing infant
flowers from low temperature (Fig. 2-10). Had the farmers not grown improved
cultivars and followed improved cultivation method, they had harvested no grainin 1993. This could have led to a famine similar to those that occurred more than
50 years ago.
In the present decade, special attention has been paid to improve the eating
quality of steamed rice of Hokkaido. It has been improved by two factors,
breeding and climate change. The objective of rice breeding in Hokkaido has

2-9Table 2-5. Agricultural land area in 2005.
Japan Hokkaido Ratio(1000ha)
(%)
Total
4692
1169
25
Puddy field
2556
228
9
Upland field
2136
941
44
Field crops 1173
412
35
Fruit tree
332
3
1
Grass
631
525
83

Table 2-6. Average farm size ofcommercial farmers in 2005.
Japan Hokkaido Ratio(%)
Land area 3447
966
28(1000ha)Number of 1963
52
3
farms
(x1000)
Average
1.76
18.59 1056
Land area(ha)

Table 2-7. Rice production in Hokkaido in 2005.
Area
Products
Yield(1000ha) (1000ton) (kg/ha)
Japan total
1702
9062
5324
Hokkaido total
119
683
5731
Ratio (%)
7
8
108
SorachiRatio (%)
Kamikawa
Ratio (%)

54
46
31
26

318
47
184
27

5865
102
5875
103
Fig. 2-7. Rice harvestingwith combine in paddy
field.

Fig. 2-8. Rice ears with fertile grain (left figure) and unfertile grains (rightfigure) at the end of growing season. (Photographs of Dr. T. Satake)2-10

been changed since 1980s because of a rapid decline in the demand of rice inJapan. Rice production in Japan exceeded the consumption in 1970. Since thenthe Ministry of Agriculture, Forestry and Fishery (MAFF) has imposed restriction
on rice cultivation (“Tensaku”, changing rice cultivation to other crops)
throughout Japan (Table 2-3). Before 1970, the main objective of rice breeding in
Hokkaido was to enhance tolerance to cool weather. Breeding to improve eating
quality was paid little attention for a long period. As a result, the main cultivar‘Ishikari’, which contributed about 60% of rice production in Hokkaido in 1970s
had lower eating quality relative to the leading cultivars such as ‘Koshihikari’ and‘Akita-komachi’ grown in the main islands of Japan. Therefore, the MAFF
imposed the maximum restriction on cultivation of rice in Hokkaido, which
accounted for about 50% of paddy fields. It resulted in a rapid reduction in rice
area in Hokkaido, from 266,000 ha in 1969 to 135,000 ha in 2000 (Table 2-3).
To cope with the above situation, since 1980s, the rice breeding in Hokkaido
has been targeted to improve the eating quality. Farmers’ union of Hokkaido
contributed money to set up new and efficient equipments at the breedingstations of Hokkaido Agricultural Experiment Station to test the eating quality(mainly amylose content). As a result of these efforts by both researchers andfarmers, a new rice cultivar ‘Kirara 397’ with improved eating quality was
released in 1988. Its quality was, however, still lower than that of ‘Koshihikari’.
However, because of low production cost resulting from large field size andmechanization of cultivation, ‘Kirara 397’ could be sold at a much cheaper rate
than that of ‘Koshihikari’. This raised its popularity throughout Japan, especiallyat first food restaurants such as “Yoshinoya”. Since then, new cultivars such as‘Hoshinoyume’, ‘Nanatsuboshi’ etc. with more superior quality have beenreleased one after another in Hokkaido. The latest cultivar ‘Yumepirika’, released
in 2008, has an excellent quality, equivalent or better than ‘Koshihikari’ grown inmain islands.
Another factor that improved the eating quality of rice produced in Hokkaido
is the change in climate, which is a global phenomenon. In general, the eating
quality of rice depends on the proportion of amylose and protein, which control
the stickiness and softness of steamed grains. The best combination forJapanese consumers is 16.5% of amylose and 6.0% of protein. Low

2-11

Percent of fertile grains

Fig. 2-9. Relationship between
the released year of cultivars
and the percentage of fertile
grainsat

Kitamura(open

square) and Kamikawa (closed
circle) in 1993.
(Iwama et al. 1998)
Released year of cultivar

Fig. 2-10. Paddy fields maintaining irrigation water at a high depth to protect
the temperature decrease in the young panicle (left figure), and artificial
climate regulation facilities to examine the mechanism of cool weather
damage in rice panicles (right figure) at the Kamikawa Agriculture Experiment
Station.

(Photographs were provided by Dr. H. Tanno)

2-12temperature during the ripening period of grain from August to September in
Hokkaido frequently restricts the decrease of amylose and protein in grains.
However, global climate change has caused some increase of temperature insummer and autumn. This has helped the cultivars with improved eating quality
to express their full genetic performance. In the southern parts of Japan, on thecontrary, summer temperature sometimes exceeds those required for normal
grain development and thus results in lower quality. It is hoped that Hokkaido will
become a leading rice producer area of Japan in the next decade not only forquantity but also for quality of rice produced.
(2) Wheat
Wheat is cultivated in116,000 ha in Hokkaido, which is 54% of total area of
wheat in Japan (Table 2-8). In Hokkaido, wheat is mainly cultivated in thenorthern and eastern parts i.e. Kitami, Abashiri and Tokachi (Fig. 2-1), where it iscultivated in upland fields. Wheat is also cultivated in paddy fields in the central
part of Hokkaido i.e. Ishikari, Sorachi and Kamikawa (Fig. 2-1).
Average yield (4.7 ton/ha) of wheat in Hokkaido is much higher than in theother parts of Japan (3.4 ton/ha). It contributes 62% of total wheat production ofJapan. Two types of wheat, winter wheat and spring wheat are grown in
Hokkaido. Winter wheat is sown in the first fortnight of September. Before snow
fall, the plants grow to 10 cm and have 6 to 8 leaves (Fig. 2-11). After snow fall,snow-cover protects the plants from severe low temperature of winter. Snowmelts in April and the plants start growing again, and reach the heading stage inearly June. The harvesting is done from late July to early August. The
development of improved high yielding cultivars at the Hokkaido Experimental
Station has led to a rapid increase in wheat production in the current decade.
The latest cultivar ‘Kitahonami’ (Fig. 2-12) has high grain quality comparable toAustralian Standard Wheat (ASW), which is suitable for making Japanese
noodles. This cultivar was released in 2007, and its hulled grain yield recorded
more than 10 ton/ha in farmer’s fields.
Spring wheat is sown after snow melts in April. It grows rapidly, reaches theheading stage in late June, and is harvested in mid August. As spring wheat gets
much shorter growth period than winter wheat, the average yield (hulled grain) of

2-13

Table 2-8. Wheat production in Hokkaido in 2005.
Area
Products
Yield(1000ha) (1000ton) (kg/ha)
Japan total
214
875
4097
Hokkaido total
116
540
4676
Ratio (%)
54
62
114
TokachiRatio (%)
Abashiri
Ratio (%)
SorachiRatio (%)
Kamikawa
Ratio (%)

46.2
40
26.2
23
15.6
14
12.7
11

231.2
43
148.2
27
61.3
11
44.3
8

5004
107
5656
121
3929
84
3488
75

Fig. 2-11.

Winter wheat fieldin Tokachi in late autumn.

Fig. 2-12. High yielding winterwheat cultivar ‘Kitahonami’ at the
ripening stage.

Fig. 2-13. Drill seeding machine (top figure)and harvester (bottom figure) used in wheat
cultivation at big farms in Hokkaido.
(Bottom figure was provided by Prof. Y.
Shibata of Hokkaido Univ.)

2-14

spring wheat in Hokkaido is about 30 ton/ha. However, spring wheat has highprotein content and thus there is a strong demand for this from bread makers.
Presently, spring wheat shares less than 10% of wheat area in Hokkaido, mainlyin the central part, i.e. Ishikari and Sorachi. In these areas, early winter sowing(“Syotou-maki”) of spring wheat is increasing. The spring wheat is sown justbefore snow fall in late autumn, and it germinates just after snow melting in early
spring. Since the growing period becomes slightly longer in early winter sowing
relative to general spring sowing, the yield increases about 20%. The latest
cultivar ‘Harukirari’ released in 2007 has high grain quality almost comparable tothe imported Canadian wheat used for bread making, and it is expected toincrease the spring wheat cultivation in Hokkaido.
The cultivation of wheat in Hokkaido is fully mechanized as in Europe.
Seeding is done with a drill planter and harvesting with a combine (Fig. 2-13).
The average labor requirement of wheat is about 30 hours per ha, which is thelowest among field crops in Japan.
(3) Potato
Potato being adapted to cool climate is cultivated in all areas of Hokkaido.
Hokkaido has 56,000 ha of potato, sharing 64% of potato area in Japan (Table
2-10). Average potato yield in Hokkaido is much higher (39 ton/ha of freshtubers) than in other parts of Japan (20 ton/ha); thus Hokkaido contributes 78%
of Japan’s potato production.
Depending on the usage, three types of potatoes are cultivated in Hokkaido:
table potatoes (for household usage), processing potatoes (for chips and Frenchfries), and starch potatoes (for starch), with 16, 22 and 47% of potato area of
Hokkaido, respectively. The leading cultivars for table potato are ‘Danshaku-imo’and ‘Kitaakari’, for processing are ‘Toyoshiro’ and ‘Sayaka’, and for starch
production is ‘Konafubuki’ (Fig. 2-6). Presently, the production of starch potatoes
is decreasing because of severe competition with the imported potato starch andcorn starch, which are cheaper. On the other hand, the production of processing
potatoes is increasing because of the increase in consumption of chips andFrench fries, especially by young generations.
Hokkaido is also famous for the production of seed tubers. The National

2-15

Table 2-9. Potato production in Hokkaido in 2005.
Area
Products
Yield(1000ha) (1000ton)(ton/ha)Japan total
87
2749
31.6
Hokkaido total
56
2151
38.6
Ratio (%)
64
78
122
TokachiRatio (%)
Abashiri
Ratio (%)
Shiribeshi
Ratio (%)
Kamikawa
Ratio (%)

23.6
42
18.2
33
4.5
8
3.4
6

831
39
730
34
136
6
119
6

35.2
91
40.1
104
30.7
79
35.0
91

Fig. 2-14. Propagation of virus-free seedlings in-vitro condition (top figure)and microtubers produced from transplanted seedlings (bottom figure) at
the National Center for Seeds and Seedlings in Hokkaido.

Fig. 2-15.

Planting of seed potato (top left), cultivation of rows to prevent

weeds (top right), spraying of pest sides (bottom left) and harvesting (bottom
right) of potato in Hokkaido. (Left figures were provided by Prof. Y. Shibata)2-16

Center for Seeds and Seedlings (NCSS) is producing seed tubers at four
farms located at Shiribeshi, Kitahiroshima, Iburi and Tokachi in Hokkaido (Fig.
2-14). The tubers produced at these farms are sold to progressive farmers, who
propagate the seed tubers under the inspection of the Plant Protection Office ofMAFF. Only these farmers are permitted to sell their potato produce as seedtubers to other farmers. The seed tubers produced in Hokkaido are used not
only in Hokkaido but also in the other parts of Japan.
Mechanization of potato cultivation is progressing in Hokkaido. Planting andharvesting are done with automatic machines attached to big tractors (Fig. 2-15).
The average labor requirement of potato cultivation is 100 hours per ha, andonly about 50 hours per ha for production of starch potatoes in big farms.
(4) BeansThree kinds of beans, soybean, adzuki bean and kidney bean (Fig. 2-16, Fig.
2-17), are cultivated in Hokkaido on a total area of 60,000 ha comprised of
28,000 ha with soybean, 23,000 ha with adzuki bean and 9,000 ha with kidneybean (Table 2-10). Although beans are sometimes damaged by cool weather,
they enrich soil by nitrogen fixation in their root nodules. Therefore, theircultivation is useful as it helps to maintain wheat-potato-sugar beet crop rotation
system for 4 years in upland fields in Hokkaido.
Hokkaido contributes 23% of total soybean production of Japan (Table 2-11).
In Japan, soybean is generally cultivated in lowland fields used for ricecultivation. In Hokkaido, however, soybean is cultivated in both low land fields
and upland fields. Tokachi is the main area of soybean cultivation in upland fields
accounting 22% of total soybean area of Hokkaido. Soybean yield in Hokkaido is
2.5 ton/ha, which is much higher than an average of 1.5 ton/ha in the other partsof Japan. The present leading cultivar of soybean is ‘Yukihomare’ bred in 2001. It
has a determinate growth habit and large grain size (about 350 mg). The grains
are mainly used for traditional Japanese foods, such as “tofu” (soybean pudding)and “Natto” (fermented soybeans) (Fig. 2-17), and brewing of “miso” (soybean
paste) and “shoyu” (soy sauce). A special cultivar ‘Suzumaru’, of very small grain
size (about 100 mg), is used for making “Natto”.
Adzuki bean originated in Japan and is cultivated only in Hokkaido. Japanese

2-17

Table 2-10. Cultivating area and yield of beans in Hokkaido.
SoybeanAzuki bean
Kidney bean
Year
Area
Yield
Area
Yield
Area
Yield
(1000ha) (t/ha)(1000ha) (t/ha)(1000ha) (t/ha)
1894
8.8 1.72
15.4
1.05
1.8 1.94
1900
29.2 1.66
30.1
1.60
9.5 1.66
1910
76.9 1.23
52.1
1.29
13.6 1.56
1920
102.0 1.33
53.5
1.33
57.9 1.08
1930
80.2 1.49
46.7
1.51
91.5 1.45
1940
85.5 0.84
40.5
0.86
90.3 0.92
1950
86.1 1.41
19.6
1.40
33.1 1.38
1960
68.0 1.59
60.5
1.63
78.0 1.68
1970
10.0 1.62
43.8
1.55
67.5 1.75
1980
23.1 1.65
29.9
1.26
20.0 1.50
1990
12.7 2.60
40.4
2.38
20.3 1.48
2000
16.2 2.66
30.0
2.53
11.3 1.21
2006
28.1 2.49
22.8
2.46
8.9 2.03

Total
Area
(1000ha)
26.0
68.8
142.6
213.4
218.4
216.3
138.8
206.5
121.3
73.0
73.4
57.5
59.8

Table 2-11. Soybean production in Hokkaido in 2005.
Area
Products
Yield(1000ha) (1000ton) (kg/ha)
Japan total
134
225
1679
Hokkaido total
21
52
2483
Ratio (%)
16
23
148
Kamikawa
Ratio (%)
TokachiRatio (%)
SorachiRatio (%)

5.0
23
4.7
22
4.5
21

12.0
23
13.3
25
11.0
21

2424
98
2824
114
2428
98

Fig. 2-16. Soybean at the
ripening stage.

Fig. 2-17. Grains of soybean (topleft), adzuki bean (top right) andseveralkindsofkidney(bottom).

Fig. 2-18. Traditional Japanese foods made from soybean
grains, Tofu (left) and Natto (right).

2-18

beans

call this “Adzuki”, because of its small grain size. Adzuki bean is used to makefestive red rice and bean jam. The leading adzuki bean cultivar is ‘Erimoshozu’.
The yield and quality of Japanese adzuki bean are much higher than theimported adzuki bean, which is mainly from China. However, Hokkaido’s adzuki
bean is more than 7 times expensive than the imported ones. The annual
variation in yield is large because of variation in damage due to cool weather.
The need thus is to assure stable production and reduce the cost of production.
Compared with wheat and potato, there is little mechanization of beancultivation, particularly for harvesting (Fig. 2-19). As a result, the average labor
requirement, for example of soybean cultivation is more than 100 hours per ha.
This results in much higher price of soybean produced in Hokkaido compared tothe imported ones, mainly from USA and Brazil. The use of harvester speciallymodified for beans is increasing in big farms of Tokachi and Ishikari.
(5) Sugar beet
Sugar beet (Fig. 2-20) is cultivated on 69,000 ha in Hokkaido, and there is noarea under sugar beet in other parts of Japan (Table 2-12). The average yield is
53 ton/ha, which is as high as in Europe. It is used to produce sugar underprotection of the Japanese government. Sugar beet area is mainly in thenorthern and eastern parts of Hokkaido i.e. Tokachi and Abashiri (Fig. 2-1). In
these areas many factories to produce sugar from sugar beet are located.
The sowing method of sugar beet in Hokkaido is typical. To regulate thenumber of plants per hill, seedlings are first grown in paper pots in a nursery bed
and then transplanted in fields. This also reduces weeds. The transplanting ispartly mechanized, but complete mechanization is needed to reduce theproduction cost. Although the yield of the crop grown from direct seeding isabout 20% lower than that in the transplant-crop, direct seeding with seedingmachines is increasing to reduce the production cost. Improvement in seeding
methods and development of cultivars adapted to direct seeding is underway.

2-19

Fig. 2-19. Drying the harvested soybean (Niozumi in Japanese) in fields
before threshing.

Table 2-12. Beet production in Hokkaido in 2000.
Area
Products
Yield(1000ha) (1000ton)(ton/ha)Japan total
69
3673
53.1
Hokkaido total
69
3673
53.1
Ratio (%)
100
100
100
TokachiRatio (%)
Abashiri
Ratio (%)
Kamikawa
Ratio (%)

Fig. 2-20.

30.6
44
27.4
40
4.6
7

1637
45
1531
42
232
6

53.5
101
55.9
105
50.2
95

Sugar beet field in early autumn at Kitami.

2-20