TROPICS Vol. 22 (4) 131-155 Issued March 1, 2014

REVIEW ARTICLE A review of studies on swidden agriculture in Japan: cropping system and disappearing process

Satoshi Yokoyama1*, Isao Hirota2, Sota Tanaka3, Yukino Ochiai4, Eiji Nawata5 and Yasuyuki Kono6

1 Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8601, Japan 2 Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, 464-8601, Japan 3 Multidisciplinary Sciences, Research and Education Faculty, Kochi University, Kochi, 783-8502, Japan 4 The Kagoshima University Museum, Kagoshima, 890-0065, Japan 5 Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan 6 Center for Southeast Asian Studies, Kyoto University, Kyoto, 606-8501, Japan * Corresponding author: [email protected]

ABSTRACT This paper reviewed some of the major study results published mainly in Japanese on swidden agriculture which was once practiced in Japan. In this review, a focus was placed on the natural environment in which swidden agriculture was practiced, cropping systems, crop cultivation in swidden fields, the transition of swidden agriculture at the end of the disappearing stage, and the utilization of millet cultivated in swidden agriculture. Swidden agriculture of temperate Japan featured cultivation primarily of millet, and was characterized by highly sophisticated and complex cropping systems according to the natural environment, which varied from one region to another. In the 1970s, however, swidden agriculture which had been continuously practiced as a primary means of subsistence in mountainous areas of Japan ceased to exist. Accordingly, the review will primarily focus on studies from the 1950s to 1970s, the post-war period in which a large number of research findings were produced from the perspectives of the humanities and natural sciences. The methodologies and perspectives adopted in the studies on Japanese swidden agriculture are definitely applicable to currently conducted studies of swidden agriculture in tropical regions.

Key words: swidden agriculture, cropping system, continuous cropping, millet

INTRODUCTION of passively watching swidden agriculture disappear. With these issues as a background, we address A large volume of studies on swidden agriculture, Japanese swidden agriculture which has already become which has been widely practiced across the subtropical and extinct. In Japan, swidden agriculture had been practiced tropical regions, has been accumulated in the field of widely in mountainous areas in regions extending from natural sciences. Currently, the sustainability of swidden Tohoku to Kyushu for hundreds of years. The form of agriculture as an agricultural technique is being discussed. swidden agriculture varied according to the natural Under the growing interests on global environment and the conditions, and a large variety of crops were cultivated. spread of market economy, however, there is a serious Following a history of expansion and contraction in debate on how swidden agriculture should be positioned in response to social changes, Japanese swidden agriculture as the present and future rural development and forest a means of subsistence vanished completely in the 1970s. conservation efforts. In Southeast Asia, research works Swidden agriculture itself is still practiced in some areas have been conducted on swidden agriculture with a focus today: however, the purpose of this practice is to preserve on factors such as social organizations and livelihood local cultural traditions and to produce special regional systems. Nonetheless, since most of the studies are field products. Although swidden agriculture has disappeared as work-based case studies and their results are constrained by a means of subsistence, a large volume of accumulated the biophysical and socioeconomic characteristics of the studies are available on the history of changes in swidden study site, perspectives on the long-term transformation of agriculture throughout the 20th century. swidden agriculture are not fully figured out yet, and no Unfortunately, the swidden agriculture that has become substantive progress has been made in discussions on the extinct in Japan has not been discussed at all in the studies above question. This has created the ongoing circumstance of swidden agriculture conducted by researchers outside 132 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

Japan, most of which has dealt with swidden agriculture in tropical regions. the tropical regions. One of the reasons why the studies of In the subsequent sections, an overview of Japanese Japanese swidden agriculture remain unknown outside natural environment is first described. Then, previous Japan is probably the fact that very few papers on this topic studies are reviewed on various topics associated with the have been made available in English. It is even possible swidden agriculture practiced in Japan in order to that many of the researchers across the world are not even comprehensively understand Japanese swidden agriculture. aware that swidden agriculture has been practiced in Japan, The topics to be reviewed include the types of cropping a temperate country. Japanese swidden agriculture has been systems, the practice and management of swidden examined from the perspectives of multiple academic fields agriculture, the end of swidden agriculture and its causes, including folklore, geography, anthropology, and and utilization of cultivated crops in people's daily lives. agriculture. In addition, progress has been made to Areas covered in this article are shown in Fig. 1. In the integrate the results from fieldworks, field experiments, and conclusions, discussions are provided on characteristics of analyses of historical materials. Considering this swidden agriculture in temperate Japan, circumstances circumstance, the fact that research works on Japanese which led this swidden agriculture into extinction, and a swidden agriculture have not been applied in the current possibility of joining previous studies of Japanese swidden studies of swidden agriculture in tropical regions is an issue agriculture with studies of tropical swidden agriculture. to be addressed. The methodologies and perspectives adopted in the studies on Japanese swidden agriculture are ENVIRONMENTAL CONDITIONS definitely useful for predicting currently conducted studies of swidden agriculture in tropical regions such as Southeast OF SWIDDEN Asia which has considerably reduced the area of swidden Outline of the environment agriculture. Moreover, re-examinations of Japanese swidden agriculture may lead to the evolution of a new The total land area of Japan is 37.79 million hectares. study topic that may clarify differences between the extinct The climate is mostly temperate, but ranges from subarctic swidden agriculture in temperate Japan and tropical to subtropical. The average annual precipitation is swidden agriculture, which is currently on the path to being 1,700 mm, which varies regionally from 1,000 to 3,000 mm. extinct. The heaviest precipitation occurs during the rainy season Accordingly, this paper aims to review the findings from June to July and during typhoons in the summer and from studies of swidden agriculture in temperate Japan fall. In addition, on the west coast of Tohoku and in published mainly in Japanese. The review primarily Hokuriku, another important source of precipitation is focuses on studies from the 1950s to 1970s, the post-war heavy snowfall during winter. period in which a large number of research findings were Half of the country is mountainous with steep slopes, produced from the perspectives of the humanities and as shown in Table 1. Besides the Andosols and volcanic natural sciences. In particular, attention is drawn to 1) soils, most other soils are also affected by volcanic ash to cropping systems of Japanese swidden agriculture including some extent because of the country's location on the Pacific cultivation practices, 2) crop protection, and 3) changes in Ring of Fire. Original vegetation varies from evergreen 1) and 2). Furthermore, the review also looks into the coniferous forest, consisting of species such as touhi (Picea swiddeners' perceptions of the natural environment and jezoensis), akaezomatsu (Picea glehnii), and todomatsu applications of these perceptions in their practice of (Abies sachalinensis) in the north, via cool-temperate swidden agriculture. In Japanese swidden fields, many deciduous broadleaved forest, consisting of Japanese beech different types of crop were continuously cultivated over a (Fagus crenata), and mizunara (Quercus crispula), for period of several years according to natural environment. example, to warm-temperate and subtropical evergreen Many swidden villages did not reclaim a large area of land broadleaved forest referred to as shōyōjurin in Japanese or in one location but develop a few small plots of land and lucidophyllous forest, with species such as shii (Castanopsis burned forest twice or three times a year to cultivate spp.), oak (Quercus spp.), and tabunoki (Machilus different types of crop. This is covered later in this review thunbergii) in the south. There are also transitions of in more detail. Findings resulting from clarification of the vegetation depending on the elevation. Despite the above wisdom behind swidden agriculture practiced by Japanese background, many natural forests in Japan have actually swiddeners in response to the natural environment would be been replaced by secondary forests and planted forests, meaningful to compare with studies of swiddeners in which are made up of species such as Japanese cedar A review of studies on swidden agriculture in japan: cropping system and disappearing process 133

Fig. 1. Map of Japan and areas covered in the text.

Table 1. Land distribution in terms of topography, gradient, geology and soils (km2)

Topograpy1 mountain hill plateau lowland inland water and others 230,331 44,337 41,471 51,963 9,232 (61.0 %) (11.8 %) (11.0 %) (13.8 %) (2.4 %) Gradient2 ＞ 30° 20–30° 15–20° 8–15° 3–8° 0–3° 28,519 80,526 56,386 81,341 50,309 48,458 (8.3 %) (23.3 %) (16.3 %) (23.5 %) (14.6 %) (14 %) Geology3 sedimentary rocks igneous rocks metamorphic rocks 210,680 150,404 14,458 (56.1 %) (40 %) (3.8 %) Soil4 brown forest soil Andosol alluvial soil others 201,620 65,371 56,639 50,740 (53.9 %) (17.5 %) (15.1 %) (13.6 %) 1 Data are based on the 1982 Research and Management on Land Numerical Information. Statistics Bureau (2009) 2 Data are based on the 1982 Research and Management on Land Numerical Information, and excluding the area of lakes and rivers. Statistics Bureau (2009) 3 Excluding the area of lakes and rivers. Murata and Kano (1995) 4 Excluding the area of lakes, rivers and built-up areas. Kanno et al. (2008).

(Cryptomeria japonica) and Japanese cypress (Chamae- constituting 0.97 % of the total land area, although the cyparis obtusa). Planted forests constitute 40 % of the total vegetation zone of this forest type accounts for 53.4 % of forest area of 25 million hectares. However, lucidophyllous the country (Ohno 2005). forests remain in scattered areas in Western Japan, 134 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

soil fertility there could be improved by the downward Topography of swidden movement of material along long slopes; village forests Swidden agriculture was generally distributed across (satoyama) usually located on hills with a gentle and short the country on relatively high mountains with steep slopes. slope were not suitable for swidden, although the It was typically carried out at elevations exceeding 400 m in conversion of such forest to permanent paddy or upland the Hokuriku region, 600 m in the Tohoku region, and fields and its management using fertilizer could easily be 1,000 m in the Kyushu region (Sugawara 1980a). The implemented. elevation limit for this type of agriculture was 1,000 m in The gradient of swidden land was reported to be 30 to the Hakusan area, which is the lower limit of distribution of 45° in the Sanekawa area in Niigata Prefecture (Sugawara and Japanese beech (Tachibana 1995: 23) and 1,400 m in the Shindo 1986), 35 to 45° in the Tsubayama area (Fukui 1974: Shikoku Mountains, which is the upper limit for the 65), and 15 to 20° in the Shiiba area (Kamada and Takahashi cultivation for oriental paper bush (Edgeworthia 1992). In the Hakusan area, the gradient often exceeded 40 chrysantha), an important cash crop used as a source of to 50° (Tachibana 1995: 82). Sawamura (1950) supposed that, Japanese paper (Sōma 1962). although swidden agriculture had been formerly conducted The establishment of swidden on the upper parts of under any topographic conditions, flat and gentle slopes slopes and ridges was generally avoided because of the low were converted to permanent uplands and paddy fields, fertility and unfavorable moisture conditions of these soils, resulting in the remaining steep slopes being the only places as well as the possibility of landslides. In contrast, the available for swidden agriculture. In Aizu area, land with a lower parts of slopes, the bottom of valleys, and concave gentle slope was selected for swidden agriculture with slopes were regarded as suitable for swidden because of the clear-cutting in September and burning in spring to prevent favorable soil conditions, particularly in the Hakusan area slashed materials from being transported downhill with the (Tachibana 1995: 84–89) and the Shiiba area (Kamada and snow. However, such land was changed to permanent Takahashi 1992). Swiddeners in snowy areas believed that fields, resulted in the decline of this type of swidden (ibid.). the establishment of swidden agriculture in areas to which Because soil erosion and ash outflow were problems for avalanches would slide down and deposit would result in swidden on steep slopes, various measures were taken to better production (Nomoto 1984: 594–600). In the protect them (Table 2). An interesting report from the Tsubayama area (Niyodogawa Town, Kochi Prefecture), Shiiba area stated that land with a slope of 15 to 20° was swiddeners perceived that depressions in mountains (sako) preferable as it mitigated the burden of painful stooping were suitable for any crops because of their deep soils with works such as weeding (Kamada and Takahashi 1992). favorable moisture conditions, while limited kinds of crops In terms of slope orientation, in regions with heavy such as Japanese barnyard millet (Echinochloa esculenta), snowfall such as the Hakusan area, slopes facing to south foxtail millet (Setaria italica), soybean (Glycine max), and and west were preferable because snow would melt earlier azuki bean (Vigna angularis) could be planted on ridges (Tachibana 1995: 80). In addition to slope orientation, the (une) (Fukui 1974: 46). Kamada and Takahashi (1992) sunshine was recognized as an important factor for the reported that, in the Shiiba area, land was classified into selection of swidden location; indeed, many local words steep (tachiyama) and gentle (hirachi) in terms of the related to this have been documented (Fukui 1974: 34–56, gradient of its slope, and buckwheat (Fagopyrum Kamada and Takahashi 1992, Matsumoto 2006: 164). In esculentum) was planted with summer burning on gentle the Tsubayama area, when swidden land was shaded by a slopes but not on steep slopes because of the occurrence of tree growing on adjacent land, the tree could be cut down frost. These terms may also refer to different elevations up with the owner's permission (fukegiri) to secure direct a mountain, although this was not clarified in this reference. sunlight (Fukuda 1989). According to Tachibana (1995: 88–89), swidden agriculture in the Hakusan area had often been discussed negatively as CROPS AND CROPPING SYSTEMS the only possible option because in that the topography of high and steep mountains impeded the conversion of OF SWIDDEN AGRICULTURE swidden fields to permanent upland or paddy fields. Crops in swidden agriculture However, he emphasized that under the condition that fertilizer could not be brought in from the outside, swidden In Japanese swidden agriculture, various crops were agriculture was a reasonable agricultural technique, cultivated (Table 3). Among these, five crops, namely, particularly on the lower slopes of high mountains because buckwheat, Japanese barnyard millet, foxtail millet, soybean, A review of studies on swidden agriculture in japan: cropping system and disappearing process 135

Table 2. Measures to prevent soil erosion and ash outflow

Area Measures Hakusan area1 Driving stakes to hold fuel woods not to slide down. Tubayama area2, Shiiba area3 Laying logs or branches along contour lines to prevent erosion as well as to make footholds. In Narada, Yamanashi Pref.4 Tsubayama, Japanese chestnut (Castanea crenata) was preferred because being less decayed. Sanekawa, Niigata Pref.5 Piling up more fuel woods on the upper part of a slope, reckoning downward ash movement. Niigata Pref.6 Sowing more seeds on the upper part of a slope, reckoning downward movement. Yamagata Pref.7 Sowing buckwheat on the upper part of a slope and turnip in the lower part if planted in the same slope. 1 Tachibana (1995: 82) 2 Fukui (1974: 95) 3 Kamada and Takahashi (1992) 4 Matsumoto (2006: 116) 5 Sugawara and Shindo (1986) 6 Sugawara and Shindo (1981b) 7 Nomoto (1984: 594–600)

Table 3. Cultivated crops of Japanese swidden agriculture1

Scientific name Family Japanese English Brassica rapa var. glabra Brassicaceae kabu turnip Brassica rapa var. nippo-oleifera Brassicaceae aburana Japanese rape Broussonetia kazinoki × B. papyrifera Moraceae kouzo paper mulberry Colocasia esculenta Araceae satoimo Japanese taro Echinochloa esculenta Poaceae hie Japanese barnyard millet Edgeworthia chrysantha Thymelaeaceae mitsumata oriental paper bush Eleusine coracana Poaceae shikokubie finger millet Fagopyrum esculentum Polygonaceae soba buckwheat Glycine max Fabaceae daizu soybean Hordeum distichon Poaceae hadaka-mugi hulless barley Hordeum vulgare Poaceae rokujyo-ōmugi six-rowed barley Ipomoea batatas Convolvulaceae satsumaimo, kansho sweet potato Morus bombycis, Morus spp. Moraceae kuwa, yamaguwa mulberry Oryza sativa Poaceae okabo upland rice Perilla frutescens var. frutescens Lamiaceae egoma, aburae yegoma Raphanus sativus var. longipinnatus Brassicaceae daikon Japanese radish Sesamum indicum Pedaliaceae goma sesame Setaria italica Poaceae awa foxtail millet Solanum tuberosum Solanaceae jyagaimo, bareisho potato Triticum aestivum Poaceae komugi bread wheat Vigna angularis Fabaceae azuki azuki bean Zea mays Poaceae toumorokoshi maize 1 Sasaki (1972: 96–97) and azuki bean, have played major roles in Japanese swidden rice was only seen in Japanese swidden systems in Miyazaki agriculture, according to Sawamura (1951) and Sasaki (1972), and Kagoshima Prefectures, both of which are located in who undertook groundbreaking studies on this topic. These the south of Kyushu Island. Sasaki (1971: 133–137, 1972: crops are suitable for acidic soils in a reduced state in 96–97, 247) also pointed out that upland rice was only a swidden fields. component of Japanese swidden systems in some mountain Upland rice (Oryza sativa), which is a major crop in ranges on Kyushu Island and in Okinawa Prefecture. The swidden agriculture in Southeast Asia, was rare in Japanese first introduction of rice into Japan was considered to have swidden agriculture. According to Sawamura (1951), upland occurred older than 6,400 years ago (Sato 2002: 59–60). 136 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

Sato (1992: 93–94, 2002: 62–63, 2008: 184–187) mentioned knowledge was passed down orally that turnip production that rice from the Asian continent was short-day plant, is favorable on Andosols located on north-facing slopes which is one of photosensitive types, and was difficult to where Japanese knotweed (Fallopia japonica) and Japanese harvest in the north before getting cold and snowfall pampas grass (Miscanthus sinensis) grow well (Nomoto because of its late flowering. In mountainous areas, 1984: 598). Although turnip in the Atsumi area was an temperature is generally lower, and rice is difficult to grow. important subsistence crop for farmers until relatively Along with these environmental factors, Miyamoto (1968) recent years, it is now changed into a commercial crop and Sasaki (1971: 296) pointed out the mismatch between (Aoba 1993: 257). According to Yamazaki and Egashira the existing“ swidden culture” and newly introduced“ rice (2009), turnip produced in Atsumi area is mostly processed culture”. This mismatch might be one of the barriers for into sweet pickles in the last 30 years and sold throughout swiddeners to adopt rice growing. However, considering the country. Turnip in the Atsumi area, however, is still that bread wheat (Triticum aestivum) and barley (Hordeum cultivated by method of swidden agriculture. The reason vulgare), similarly new crops for Japanese, were widely why swidden agriculture continues to cultivate turnip in this introduced before rice introduction to Japanese swidden area is that farmers understand turnip cultivated in swidden systems, this issue that rice culture did not match swidden field tastes better than that in permanent upland field culture may have a room to reconsider. (Egashira 2007b). The understanding of ecology of the Japanese swidden Classification of cropping systems agriculture was particularly focused on the features of specific crops. For example, the conditions around the Various kinds of crop were found in traditional elevation limit were unfavorable for the growth of Japanese Japanese swidden agriculture, and the combination of these barnyard millet and foxtail millet because of dry and low- crops enabled diversification of cropping systems (Fig. 2). fertility soils, strong wind, low temperature, and heavy Yamaguchi (1938), documenting the distribution of snowfall in the Hakusan area (Tachibana 1995: 74–80). Japanese swidden agriculture for the first time, classified it This limit also corresponded to that for the growth of into two groups: one group mainly focused on production mulberry (Morus bombycis, Morus spp.), which was of herbaceous crops, and the other group focused on planted as a cash tree crop in the swidden field. In the silviculture. He mentioned that the former type had shifted Tsubayama area, a family allocated their land considering to the latter type after the Meiji Restoration, in accordance the distance from their home and sunlight conditions: land with the development of accessibility to market. Sasaki near their residence was planted with wheat or hulless (1972: 124–155) added information on these types and barley in sunny places after burning in fall and with pointed out three major types of Japanese swidden buckwheat in the remaining shaded areas after burning in agriculture, namely, cereal production type, perennial summer. Land on distant, high mountains was planted with commercial crop production type, and pre-forestry agro- Japanese barnyard millet after burning in spring, production type. The first of these is considered to be the irrespective of the sunshine conditions, because of frost traditional type of Japanese swidden agriculture with a long starting from early fall and snow persisting until late spring history, whereas the second and third ones are historically (Fukui 1974: 50–53). new and became common after infiltration of market Turnip (Brassica rapa var. glabra) was an important economy. In the cereal production type, Japanese and widespread crop in swidden agriculture after burning in swiddeners had been cultivating many crops, especially fall along the Japan Sea coast, an area affected by heavy various types of millet and leguminous crops, but their snowfall. Egashira (2007a) pointed out several advantages main concern was to produce millet for subsistence. of turnip planting along the Japan Sea coast in Yamagata Although some commercial crops, such as turnip and Prefecture: 1) raw turnip could be stored in snow over a yegoma (Perilla frutescens var. frutescens), were also long period without freezing, 2) turnip was an important cultivated in original Japanese swidden, their cultivation source of vitamins during the winter, 3) the turnip growth was very limited until relatively recently, probably after the period was short (two to three months). Therefore, it could onset of the Meiji era (during the period 1868–1913). be sown in fall and be harvested before snow. In addition, Meanwhile, there were crops of which production increased the amount of turnip seeds to be sown could be adjusted after World War II, such as Japanese rape (Brassica rapa based on the expectation of the yields of grain crops which var. nippo-oleifera) and Japanese radish (Raphanus sativus were going to ripen around burning time in fall for turnip var. longipinnatus). In this section, the details of the cereal cultivation. In the Atsumi area in Yamagata Prefecture, production type, which Sasaki (1972: 124–133) divided A review of studies on swidden agriculture in japan: cropping system and disappearing process 137

Fig. 2. Types and rotational patterns of Japanese swidden. into five groups, are described. Most Japanese researchers millet or foxtail millet was cultivated in the first year. In subsequently used this system of categorization, which is the second year, usually one type of millet was cultivated. very useful to understand patterns of cropping systems in In the third year, one of the legumes was cultivated, partly Japanese swidden agriculture. Although there were a lot of because of the depletion of soil fertility due to the demonyms (local idioms) related to swidden agriculture in cultivation in the preceding years. In the fourth year, millet Japan (Sugawara 1980c, Inomata 1959, Kurata 1937), the was cultivated again, and in the fifth year, millet or other types as mentioned below are named by using typical crops were sometimes cultivated when the soil was fertile. demonyms of swidden agriculture in each region. These In some cases, vegetation was cleared, swidden fields were types are Nagihata, Koba, Kano, Araki, and Konsai (root burnt in summer, and buckwheat was selected as the first crop type). The Nagihata type is the most representative year's crop. In these cases, grassland, instead of forest, was and widespread type of Japanese swidden agriculture, while often used for swidden fields. the others differ from it in order to suit local environmental In the Hokuriku and Tohoku regions, swidden agricul- and social conditions. The Konsai type has rather similar ture was adapted to the heavy snowfall area, which required and simple cropping system among cultivation years and more labor than in other regions to ensure food security could be influenced by the culture from Insular Southeast (Shindo and Sugawara 1989). In the Hakusan area, clear- Asia (Nakao 1966: 60–75). cutting for spring burning was performed in the previous summer. In cases of using old secondary forest, clear- Nagihata type cutting was performed twice: the undergrowth including As mentioned above, the Nagihata type is considered small trees was first slashed in summer, followed by the to be the most representative type of Japanese swidden felling of trees with a larger trunk in early spring because it agriculture, distributed in the central mountainous areas of was easier to work on hardened snow in this season Japan, namely, parts of Fukui, Ishikawa, Toyama, Gifu, (Tachibana 1995: 106–109). The slashed undergrowth was Nagano and Shizuoka Prefectures, and Chugoku mountains used for burning in swidden, while felled trees were (Sasaki 1972: 124–133, Matsuyama 1969). Major crops of transported on a sled to residences to be used as fuel or this type were millet, such as Japanese barnyard millet and building materials. In the Akiyamagō area, blighting trees foxtail millet, and leguminous crops including soybean and by girdling was one of the felling techniques, as well as the azuki bean, as well as buckwheat. This type lacked winter two-step clear-cutting technique as used in the Hakusan crops like wheat and barley. The Koba type has similar area (Nomoto 1984: 32–33). crops. Typically, forests, in many cases averaging more than Koba type 20 years old (Sugawara 1979b), were cleared and trees were dried and burnt in spring. Subsequently, Japanese barnyard The Koba type was distributed in southwestern parts 138 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al. of Japan, such as Kyushu and Shikoku Islands (Fig. 2). Kano type While various subcategories existed within this type, the relative importance of cereals was generally greater than in The Kano type was distributed mainly in Ohu and the Konsai type, and the type has 3 kinds of crops such as Dewa Mountains, and a part of Niigata and Toyama crops sown in summer, spring and fall in the first year. This Prefectures (Fig. 2). These are lowland rice growing areas, type has two main subcategories, namely, swidden with tree and most swiddeners also owned paddy fields. A role of cutting in fall and burning early in the following spring, and swidden agriculture, particularly of this type, was, therefore, swidden with tree cutting in summer and burning in late to produce supplemental crops. Major crops in this type were summer or early fall. These types of swidden were millet, buckwheat, soybean, azuki bean, and vegetables, es- differently practiced according to the crops to be cultivated pecially turnip. Traditionally, there were two subcategories thereafter (Ueno 1938). In the summer crop cultivation of of Kano: Natsu-gano (summer Kano) in summer and Haru- the first year, tree cutting was carried out the previous fall. gano (spring Kano) in spring. In Natsu-gano, trees were After the drying of trees during winter, they were burnt in cut, dried, and burnt in early to mid-August in the first year, early spring. Japanese barnyard millet or foxtail millet was and buckwheat or turnip was then cultivated and harvested sown and grown in spring and summer and harvested in before winter. In the second and third years, Japanese early fall. In some cases, after the first crop, wheat or barnyard millet or foxtail millet was cultivated during the barley was cultivated continuously in winter and the next period from spring to late summer. In the Haru-gano spring. In the second year, millet or leguminous crops, such subtype, trees were cut in fall of the previous year, and as soybean and azuki bean, were often cultivated. dried and burnt in June of the first year, after which Thereafter, both millet and legume were cultivated in Japanese barnyard millet was cultivated. In the second and alternate years. In some cases, buckwheat was cultivated in third years, leguminous crops such as soybean and azuki the first year. In these cases, trees were cut in early bean were cultivated. When Sasaki (1972: 168) carried out summer, dried for a short period, and then burnt. Seeds of an extensive survey of this type in the 1950s, the Haru- buckwheat were then sown and plants were harvested gano subtype had disappeared. In addition to these major several months later, before winter came. In other cases, two subtypes producing cereals, there was another specific the first crops were wheat or barley. In these cases, trees subtype called Kabu-gano (turnip Kano). In this subtype, were cut in late summer, dried, and burnt in early fall. The turnip was cultivated in the first year of the swidden cycle crops were then sown and harvested in spring the following on a relatively small scale. The timing of cutting and year. Although the main crops in the Koba type were burning trees and planting crops was the same as in Natsu- millet, wheat, barley, buckwheat, soybean, and azuki bean, gano. In the second year, generally, azuki bean was some root crops could also be incorporated. There was cultivated, after which the fields were allowed to lie fallow. plenty of variation in this type. Some included maize (Zea In northwestern parts of Japan, the main mode of mays) in their cropping systems (Yokokawa 1955). agriculture was paddy rice production in the lowlands in Although it was very rare to find upland rice in Japanese small watersheds. Diversified local varieties of turnip were traditional swidden agriculture, some systems of the Koba also cultivated in this subtype, some of which obtained a type, especially those in the south of Kyushu Island, high price. Even today, these local varieties of turnip are included upland rice in their cropping systems. In the Koba still cultivated for cash income by local farmers in this area type, swidden fields for millet and legume cultivation (burnt (Egashira 2007a, 2007b, Yamazaki and Egashira 2009). in spring) were generally larger than those for buckwheat Araki type (burnt in summer) or wheat or barley (burnt in fall), and were located far from the villages of swiddeners. In the The Araki type was mainly distributed in Kitakami Koba type, several variations were observed. For example, Mountains in northeastern parts of Japan, including Iwate in the north of Kyushu Island, buckwheat and Japanese rape and Miyagi Prefectures (Fig. 2). Major crops in this type were preferred as crops for the first year, followed by were similar to those in other types, including wheat, foxtail millet in the second year and Japanese taro barley, Japanese barnyard millet, foxtail millet, buckwheat, (Colocasia esculenta) in the third year, without winter and soybean. This type was characterized by its intensive crops; the applied system is considered to be a transitional cultivation. Fertilizers were applied, fields were tilled type between the Koba type and the Nagihata type. before planting, and crops were planted on ridges, which were seldom practiced in the other types. Trees were cut, dried, and burnt in spring to early summer and foxtail millet A review of studies on swidden agriculture in japan: cropping system and disappearing process 139 or soybean was cultivated in the first year. In some cases, second year. For this rotation, the swiddeners explained trees were cut, dried, and burnt in June and buckwheat or that 1) the yields of Japanese barnyard millet was twice turnip was cultivated. After the second year, one of the higher than those of foxtail millet, 2) Japanese barnyard legumes or cereals was cultivated. Generally, the period of millet had a lot of varieties and the early-maturing varieties cultivation was relatively long (more than five years) and were available at a high elevation, 3) the yields of Japanese the fallow period was shorter than that of the other types. barnyard millet were more stable than those of foxtail While most Japanese swidden fields were located on millet, and 4) foxtail millet preferred the ash from Japanese mountainous slopes, those of this type were sometimes in barnyard millet (Tachibana 1995: 53–54). In the Tsubayama the lowlands. area, foxtail millet was planted in the final year because this crop was believed to exhaust land fertility so severely that Konsai type no crop could grow the following year (Fukui 1974: 52). The Konsai type was observed on the Nansei Islands Buckwheat could be continuously cropped and harvested of Kagoshima and Okinawa Prefectures, located in the for a short duration of about three months (Sugawara southernmost part of Japan (Fig. 2). The main charac- 1980a). However, the high nutrient requirements of this teristic of this type was the cultivation of cereals and root crop resulted in poor yields of the subsequent crops and crops, such as sweet potato (Ipomoea batatas) and Japanese retarded the recovery of secondary vegetation (Tachibana taro. Swiddeners in Kuroshima Island in the Yaeyama 1995: 53). Islands, used a local agricultural calendar starting around Many studies pointed out that the nitrogen fixation November, while the lunar calendar was generally used in function allowed leguminous clops, soybean and azuki bean Japan. Single cropping of barley was practiced in summer to be planted under the conditions of low soil fertility from in the first year of this local calendar, followed by wheat in the third year. However, the importance of this ability in winter, sweet potato in summer of the second year, and cropping systems of swidden agriculture has not been foxtail millet and/or upland rice in the summer of the third scientifically verified. Finger millet (Eleusine coracana) year of this local calendar (Sasaki 1972: 242–261). In this could be planted in infertile land, as well as under case, four crops were cultivated in three consecutive years conditions of low soil fertility. Nonetheless, the planting of of the local calendar, and land was then left to lie fallow. this crop in the first or second year was avoided because it In the case of the Yaeyama Islands of Okinawa was believed to exhaust soil fertility (Nomoto 1984: 78– Prefecture, located at the most southwesterly point of the 79). According to Sugawara and Shindo (1980), a Japanese archipelago, because of the vigorous vegetation swiddener in the Sanekawa area stated that planting yegoma growth under the subtropical climate and the presence of a in the final year could promote the recovery of soil fertility genus of poisonous snakes (Protobothrops spp.), living during the fallow period, although its scientific mechanism forest stands were first burnt without clear-cutting, followed is not verified. Tachibana (1995: 381) described that, by clear-cutting, carrying away large pieces of wood for because yegoma could be planted under any conditions, it firewood, and burning small plant material (Nomoto 1985: was planted in the final year and that swiddeners believed 561–570). that rabbits disliked its smell, so they planted it around fields of soybean or Japanese cedar seedlings. Many Crop selection and production in swidden system researchers also pointed out that swiddeners would abandon As shown in the Nagihata type, cropping systems in their swidden fields if vigorous weed growth occurred, in Japanese swidden agriculture can largely be characterized view of the labor that would be required for weeding. by the planting of Japanese barnyard millet, foxtail millet, or buckwheat in the first and second years, and soybean or SWIDDEN PRACTICE azuki bean in the following years. Sugawara (1979a) examined various crop combinations and observed that the Characteristics of burning maximum total production in four years of cropping was attained by the use of Japanese barnyard millet or foxtail In Japanese swidden agriculture, one of the most millet in the first year, in spite of the larger nutrient uptake important characteristics was the variety of seasons chosen of these crops, and the resulting higher soil acidification as for burning fields and subsequent cultivation, which well as a rapid increase in the number of species of weeds. differed from region to region. The burning was carried out In the Hakusan area, Japanese barnyard millet was in spring, summer, or fall. In some villages, swiddeners planted in the first year, followed by foxtail millet in the burned swidden fields two to three times per year. About 140 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

Table 4. Cutting and burning period of swidden agriculture characterized by slow and careful downward burning from 1 in Japan the upper to the lower part of a slope (Sasaki 1972: 281–287). Period of cutting Period of burning Many phrases were documented as being used to describe this burning method, for example,“ hone made yaku” (burn Month Case study Ratio Case study Ratio to the core) and“ soko made yaku” (burn down to the . Feb. 0 0 1 0 4 bottom). The most important effect of this technique, Mar. 2 0.8 14 5.7 according to Sasaki (1972: 281–287), was the release of Mar.-Apr. 4 1.6 4 1.6 nutrients from the soil due to the heat (soil burning effect), Apr. 3 1.2 15 6.1 while another important aspect was control of the fire, so Apr.-May 2 0.8 3 1.2 Apr.-June 3 1.2 2 0.8 that it would not spread to the surrounding area. In the May 7 2.9 7 2.9 Hakusan area, the appropriate duration of burning for three May-June 5 2.0 9 3.7 Tan (about 0.3 ha) was regarded as ten hours (Nomoto June 8 3.3 20 8.2 1984: 40). Piling and reburning of unburned material was June-July 7 2.9 28 11.4 also a common practice, and the site of reburning was July 5 2.0 52 21.2 regarded as being particularly fertile (Sasaki 1972: 282). July-Aug. 27 11.0 5 2.0 However, swiddeners in the Tsubayama area less focused Aug. 72 29.4 22 9.0 on the function of ash as a fertilizer than on the role of Aug.-Sep. 30 12.2 2 0.8 burning for land preparation and weed control (Fukui 1974, Sep. 22 9.0 7 2.9 83–85). Sep.-Oct. 25 10.2 3 1.2 In spite of the detailed descriptions of burning Oct. 16 6.5 4 1.6 practices by previous researchers, one aspect of the slow Nov. 5 2.0 5 2.0 unknown 2 0.8 42 17.1 and careful downward burning technique remains unclear: Clear-cut vegetation was dried for only one to two weeks in Total 245 100.0 245 100.0 swidden agriculture, with summer or autumn burning in the 1 altered from Sugawara (1980c) Hakusan area (Tachibana 1995: 70), Niigata Prefecture (Sugawara 1980b, Sugawara and Shindo 1981a), the north 50 % of all swidden villages were reported to burn fields of the Tajima Mountains (Sasaki 1972: 404–424), and the twice a year (Sasaki 1972: 109–110), and 40 % burned them Shiiba area (Kamada and Takahashi 1992). It is likely that, from June to July (Sugawara 1980c) (Table 4). When in such burning, a young fallow forest would be selected to swiddeners burned fields in summer, buckwheat was enable sufficient drying. In the case of swidden agriculture generally cultivated. The cultivation period of buckwheat with a forest plantation or swidden with spring burning in was two to three months, so they were able to harvest it an area with heavy snowfall, tree trunks were transported as before winter came. In contrast, when swiddeners burned timber and firewood. Here, the following questions arise: their fields in fall, barley, a winter crop, played an important Could“ burning to the core” be achieved under such role. Swiddeners planted barley in fall and harvested it in burning conditions with less fuel? Did the swiddeners really late spring or early summer the following year. recognize“ burning to the core” as the most important Sugawara (1980c) analyzed swidden agriculture all factor for swidden cultivation? Could such burning produce over the country and reported that the timing of burning sufficient heat and ash to exert the positive effects on soil was generally from June to July, although some cases in fertility and crop growth? April were documented. One reason for this was to avoid Table 5 lists reported values of the maximum soil the risk of fire spreading out of control because of temperature during burning in terms of soil depth. In spite unpredictable winds in the spring. More importantly, the of large variation among the cases, a temperature exceeding main reason, he emphasized, was that burning in summer 100℃ was recorded to a maximum depth of only 2 cm. In could effectively control weeds and insects, the activities of cases in which the temperature around the soil surface which increased during this season, resulting in lower labor increased markedly, the temperature at deeper soil layers requirements. Similar reasons were given for swidden decreased gradually compared with the rapid decrease at agriculture in the Shiiba area, in which spring burning after the surface because of downward heat conduction (Fukui clear-cutting in fall was not usually performed (Kamada 1974: 82, Shindo et al. 1988, Su et al. 1995). However, few and Takahashi 1992). studies have been conducted to verify scientifically the The burning technique in Japanese swidden can be effects of burning in Japanese swidden agriculture, so this A review of studies on swidden agriculture in japan: cropping system and disappearing process 141

Table 5. Maximum soil temperature (℃ ) by burning

Fuel Surface 1 cm 2 cm 3 cm 4 cm 5 cm 10 cm Hokkaido1 34 t ha－1 100 85 47 Yamagata Pref.2 17 t ha－1 71 36 34 Yamagata Pref.2 18 t ha－1 78 38 33 Niigata Pref.3 15 t ha－1 185.1 105.5 95.7 Osaka Pref.4 4.5 kg m－2 310 225 83 82 Shimane Pref. 5 98.5 t ha－1 456 236.7 (2.5 cm) 78 Tsubayama area6 No data 400 200 100 50 Shiiba area 7 No data 53 (2.5 cm) 32 32 (7.5 cm) 1 Matsui (1946: 8) 2 Takahashi (1947) cited from Sawamura (1949) 3 After harvest of Japanese ceder (Cryptomeria japonica) [Tsuda et al. (1992) cited from Ohtsuka et al. (2006)] 4 Experimental burning on sandy soils in a flat field (4 m2) in August. Assuming 20 years fallow forest. Burning was completed for 60 min. (Shindo et al. 1988) 5 A mixed forest of Japanese red pine (Pinus densiflora) and konara (Quercus serrata). Burning in August after trunks were carried out (Su et al. 1995) 6 Spring burning (Fukui 1974: Fig. 29) 7 Secondary forest predominated by suzutake (Sasa borealis) and kumaichigo (Rubus crataegifolius). Burning in August. The data was from a reburned spot. (Kamada et al. 1987) issue cannot be discussed further owing to the lack of exchangeable bases by ash addition through burning, 2) information. rapid soil acidification caused by Japanese barnyard millet Kamada et al. (1987) and Shindo et al. (1988) investi- and foxtail millet cropping, and 3) lower soil fertility in gated the role of burning for weed control based on a ger- tillage treatment until the second year compared with no mination test. Kamada et al. (1987) found that 1) burning tillage treatment. Ohtsuka et al. (2006) investigated the reduced the seed germination of annual anemochory grass changes in soil properties during turnip cropping in Niigata species of Asteraceae, 2) burning stimulated the germina- Prefecture and reported that the fates of increased soil tion of buried tree seeds, and 3) although burning did not nutrients by the practice of burning varied at the harvesting affect perennial grass seeds, these seeds were located at time in terms of elements: for example, available P deep layers and would not germinate under cultivation remained high while exchangeable K and ammonium-N without tillage. On the other hand, Shindo et al. (1988) decreased to the levels before burning. Although some soil reported that the survivability of crabgrass (Digitaria organic matter was lost by combustion during burning and ciliaris) and foxtail grass (Setaria viridis) depended on the the increased rate of decomposition during cropping, the degree and duration of increase in soil temperature. loss did not seem to be serious when taking into account the larger amount of organic matter accumulated in the soil. Effects of burning on soil properties On the other hand, in Shimane Prefecture, Su et al. (1996) Studies on the effects of burning and cropping on soil investigated soil N dynamics under swidden agriculture. properties in Japanese swidden agriculture can be grouped Their important finding was that the N dynamics was into the following categories: 1) a series of field largely affected by variations in topography and soil experiments by Sugawara and Shindo (Sugawara 1979a; temperature, even within a single field. The increase in Sugawara and Shindo 1982, Sugawara and Shindo 1983, ammonium-N, in particular, was small at the upper part of a Sugawara and Shindo 1985, Sugawara and Shindo 1987), 2) ridge where a reduced amount of fuel was burned to prevent studies related to swidden forest plantation systems (turnip uncontrolled spread of the fire. Experimental swidden cropping with Japanese cedar or Japanese cypress planting) agriculture on Iriomote Island was conducted at a (Su et al. 1996, Ohtsuka et al. 2006), and 3) a series of subtropical evergreen broadleaved forest with biomass of studies on experimental swidden agriculture on Iriomote 200 t ha － 1. Cassava (Manihot esculenta) was planted twice Island, Okinawa Prefecture (Kamura et al. 1982, Kamura under several treatments, such as with or without tillage. and Komatsu 1991, Oya and Tokashiki 1984, Kumada et al. This experiment revealed that a large proportion of nutrients 1985). In their experiments, Sugawara and Shindo reported that accumulated in the vegetation were lost into the 1) the alleviation of soil acidity and the increase in atmosphere during burning (Oya and Tokashiki 1984) and 142 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

Table 6. Soil classification and its characteristics

Area Soil class and properties Hakusan area1 Jōden: Black or blackish brown surface soils. Soft when one steps on. High fertility. Hakuden: Reddish brown surface soils. Hard. Bitter taste. Low fertility. Shirahata: Clayey. Light blue or green color. Fertility is between jōden and hakuden. Jareishi or Manago: Angular, black rocks. Fertility of Jouden containing the rocks is very high. Tsubayama area2 Matsuchi: High moisture content. Sticky. Containing small rocks. High yields of any crops. Hardened after rain continues. Occurring frequently on mountains lower than 700 m. Onji 4: Loose soil. Occurring on distant, high mountains (ketayama). Very poor vegetation. The growth of oriental paper bush (Edgeworthia chrysantha) is lower than on Matsuchi. Husuma: Thick root mat occurring on infertile ridges. Husuma also implies the place of the root mat spreading. Sometimes 30 cm in thickness. Very combustible and a fire easily become beyond control. Akadoro: Red soils with little content of organic matter. Poor in crop growth. Kamadoro: Gray, clayey soils. Occurring on Tsue (a place affected by landslide) Sukai or Suka: Meaning rocky places. Very high productivity in spite of laborious works. Shiiba area3 Soils were roughly classified into koeji (fertile) and yaseji (infertile) and sub-classified; Kurotsuchi: Black soils. The most suitable for upland farming. Akatsuchi: Red soils. Haitsuchi: Gray soils with excessive moisture. Unsuitable for cropping Zaretsuchi: Containing pebbles. Suitable for G. max and V. angularis. In addition, calcareous soils were evaluated to be the most fertile and suitable both for cropping and forest plantation. 1 Tachibana (1995: 89–92) 2 Fukui (1974: 46–48) 3 Kamada and Takahashi (1992) 4 Onji is the local name of andosols. by the run-off of water without infiltration into soils plants indicative of fertile land, alder (Alnus spp.) was (Kamura et al. 1982). The level of soil organic matter and commonly mentioned by swiddeners in Tago Town of mineralizable organic N was decreased during a cropping Aomori Prefecture (Sasaki 1972: 159) and in the Hakusan period, although the level of ammonium-N was increased area of Ishikawa Prefecture (Nomoto 1984: 152, Tachibana by the soil burning (Kumada et al. 1985, Kamura and 1995: 92–98). In the Tsubayama area, this species was Komatsu 1991). perceived as being indicative of intermediate fertility (Table 6 in Fukui (1974)). Utsugi (Deutzia crenata) was also Indigenous soil classification and indicator plants to considered as an indicator of land suitable for swidden in estimate soil fertility the Hakusan area (Tachibana 1995: 92–98) and the Swiddeners classified soil in terms of its fertility Tsubayama area (Table 6 in Fukui (1974). In the Hakusan (Table 6). Among soil classes, those considered of high area, miyamakawarahannnoki (Alnus fauriei) and taniutsugi quality were black soils with a high level of organic matter. (Weigela hortensis) were thought to be a cross between a This can be explained scientifically by a higher level of grass and a tree and to contribute to replenishing organic nutrient release from soil organic matter decomposition matter in the soil through litter decomposition. Softwood upon burning and during cropping, as well as preferable trees such as Amur corktree (Phellodendron amurense), physical properties of the soil. Soils containing rocks were tochinoki (Aesculus turbinata), and Japanese wingnut or also valued highly. Tachibana (1995: 89–92) stated that sawagurumi (Pterocarya rhoifolia) were also indicators such soils were colluvial and the presence of angular rocks (Tachibana 1995: 92–98). In addition to these tree species, provided pore spaces for aeration and water movement herbaceous vegetation such as Japanese knotweed, thistle (Table 6). This investigation suggests that the presence of (Cirsium spp.), udo (Aralia cordata), and kuzu (Pueraria rocks contributed to better physical properties under lobata) were also listed in Niigata Prefecture (Sasaki 1972: swidden agriculture with no or minimal tillage. 124), the Hakusan area (Tachibana 1995: 95), the Various indicator plants were also used to assess land Tsubayama area (Fukui 1974: 48), and the Shiiba area fertility (or soil fertility) for swidden agriculture. Among (Kamada and Takahashi 1992). In general, such herbaceous A review of studies on swidden agriculture in japan: cropping system and disappearing process 143 vegetation tends to be observed frequently on disturbed before burning. Their experiment suggests that a decline in land. In the Hakusan area, this vegetation was found in soil fertility, that is, the disappearance of beneficial effects valleys with colluvium deposition caused by avalanches. of burning and ash, can be one of the reasons for the However, the biomass of such vegetation was insufficient abandonment. In the Tsubayama area, the fallow period for burning and required fuel brought in from outside was commonly 20 to 30 years because swiddeners (Tachibana 1995: 95–97). In Nakui area of Aomori recognized that a longer fallow period resulted in the Prefecture, Sasaki (1972: 159) reported that swiddeners recovery of a soil's physical properties, the disappearance were aware that cleared pine forests were suitable for of weed species, and the improvement of soil fertility swidden because of high soil fertility and ease of plowing. through litter input (Fukui 1974: 73–80). Sugawara and In the north of Kyushu, the land dominated by simon Shindo (1985) reported knowledge of a swiddener in bamboo (Pleioblastus simonii) was preferred for swidden, Niigata Prefecture that four years continuous cropping rather than that dominated by tree species, because of the required additional huge amounts of burning materials from combustibility of bamboo, preferable soil conditions, the outside in case of burning of ten-year-fallow forest, while prevention of soil erosion by bamboo roots, the faster no additional materials in case of burning of 15-year fallow recovery of soil fertility, and the edible shoots of bamboo forest. On the basis of a field experiment, the amount of (Kawano 2007: 146). ash produced by burning the 15-year forest was estimated On the other hand, hardwoods such as oak were to be 5 t ha － 1. In the same work, it was also reported that considered by swiddeners as indicators of low fertility in the soil fertility level remained almost unchanged during 11 the Obanazawa area, Yamagata Prefecture (Nomoto 1984: years of fallow. This suggests that nutrient levels in soils 594–595), the Hakusan area (Tachibana 1995: 93), and the during fallow periods are in a quasi-steady state through a Tsubayama area (Fukui 1974: 48). In the Hakusan area, balance between output through plant uptake, erosion, and litter fall of oak was found to decompose less and to leaching losses and input through wet and dry deposition accumulate as a thick layer over the soil surface, while soils and the weathering of minerals. Taking into account the under oak forests were hard and could not be tilled with a geography of the Japanese archipelago, typhoons carrying hoe (Tachibana 1995: 92–99). In oak forests at the upper sea salt during summer and the yellow sand phenomenon limit of cultivation in the Hakusan area, roots of from the Asian continent during early spring can be undergrowth such as yamatsutsuji (Rhododendron kaempferi important sources of nutrient input through wet and dry var. kaempferi) were spread densely in the litter layer. Such deposition. areas were called tsuzurewara (ibid.: 99–101). Tsuzurewara Although weed management and wildlife management was sometimes used for swidden agriculture, although a lot are described below, fallow period management is omitted of labor and time were required for activities such as tearing because no management of fallow forest was conducted roots out of the ground using a sickle. Another shrub under poor accessibility to fallow forest in traditional species, Japanese holly (Ilex crenata), was used as an swidden. However, fallow management was very important indicator of low fertility in the Shiiba area (Kamada and and had a major impact on the whole system of Japanese Takahashi 1992). The community of Poaceae species or swidden in the mid-20th century, as described in detail later. ferns was also listed as an indicator: for example, Japanese Weed management pampas grass, cogon grass (Imperata cylindrica) in the Hakusan area (Tachibana 1995: 63), bamboo grasses in the In Japanese swidden systems, weed management was Tsubayama area (Fukui 1974: 48), and Japanese royal fern extensive and basically depended on the length of (Osmunda japonica) in the Shiiba area (Kamada and continuous cropping period and the main crops in swidden Takahashi 1992). fields. For example, swidden agriculture of the Kano type was characterized by short cultivation and long fallow Fallow management periods, and weeding was generally carried out once before Although the phrase“ recovery of land (soil) fertility the middle of summer in the first year. From the second during fallow” has been widely used to express the benefit year, swiddeners weeded two to three times in the of letting land lie fallow, very limited information is cultivation period (Sasaki 1972: 157–172). On the other available on this process. Sugawara and Shindo (1985) hand, in the Nagihata type, weeding was a rather more examined the crop rotation of buckwheat, foxtail millet, important activity than in the other types. In the Nagihata azuki bean and soybean, and reported that the level of soil type, Japanese barnyard millet and foxtail millet were the fertility after soybean growing returned to the initial level main crops, and Sugawara (1979a) reported that these crops 144 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al. induced weeds after one year of cultivation. The cultivation sound, fencing, and moats, were termed passive ones. The period for the Nagihata type was long, and swiddeners others were active ones, that is, trapping and hunting. For performed weeding three to four times per year throughout the methods depending on odor, the sensitivity of wild boar the cultivation period. Since weeding is labor-intensive, it to certain smells was utilized. Japanese swiddeners used was performed by treading on weeds (Sugawara 1980c). In rotten meat, often meat of wild boar, fish, clothes soaked in fact, swiddeners occasionally undertook agricultural work farmers' sweat, plants with a strong smell, or broiled and after taking their shoes off to avoid transporting weed fermented rice bran, among others, for this purpose. seeds. In Japan, herbicides were widely utilized after World Methods depending on sound involved bamboo, stones, War II, whereas weeding in swidden fields was mostly done wooden boards, wind, or some devices using water. Various by hand. kinds of fencing, stone walls, embankments, and moats To verify the relationship between the yield of were also constructed. These constructions reached about Japanese barnyard millet and labor input with or without 1.5 meters in height, and prevented wild boars from tillage, Sugawara and Shindo (1987) conducted a field entering swidden fields. There were also a variety of traps experiment. They reported that a tillage treatment increased for wild boar, including pits, and devices for hitting, both the species number and the total number of germinated crushing, piercing, and shooting wild boars. weeds as well as the yield of Japanese barnyard millet, Other wild animals that damaged crops in swidden compared with treatment without tillage. Shindo et al. fields included rodents, rabbits, birds and Japanese (1988) inferred that an absence of tillage was the result of raccoons. Among these, rodents sometimes caused serious the swiddeners trying to avoid the large labor input required damage to swidden crops. Japanese farmers typically used for weeding, and that they abandoned fields earlier when rodent poison; however, there was no effective protection in they started to become overrun by weeds, rather than trying swidden fields (Tachibana 1995: 145–152). To protect to increase the yield by tillage. Furthermore, Sugawara and against rabbits and serows, swiddenners set up fence using Shindo (1983) conducted an experiment to verify the wood or bushwood. As these animals are very cautious, validity of traditional knowledge in the Tohoku and they typically only damaged the outer perimeters of Hokuriku regions that the burning of specific tree species swidden fields. Sparrows also damaged swidden crops, could restrict weed germination and growth. Burning particularly Japanese barnyard millet and foxtail millet. As treatments with yamaurushi (Toxicodendron trichocarpum) insects can also damage millet, swiddeners used bells to and Japanese snowbell (Styrax japonica) led to a higher drive them away (Fukui 1974:108–114). In fact, Japanese total yield for four years of cropping of buckwheat, farmers had observed the biological characteristics of Japanese barnyard millet, azuki bean, and soybean and to insects, and elaborated many kinds of device or method better control of plume poppy (Macleaya cordata) accordingly in order to protect their produce. germination and growth, compared with the treatments using oak and yamatsutsuji. TRANSITION AND DISAPPERANCE OF In contrast to weed control, to the best of our knowledge, no study has been conducted on disease and SWIDDEN AGRICULTURE SYSTEMS insect damage control. While the main concern of Japanese traditional Wildlife management swiddeners had been cereal production, as mentioned Wild boar, among various wild animals, is the biggest above, a large area of forest was actually necessary to threats to swidden agriculture in Japan (Nomoto 1984: sustain their livelihood. In systems of Japanese traditional 162–185, Matsumoto 2006: 128–131, Tachibana 1995: swidden agriculture, most forests could only function as 145–152). The damages were so serious that various rituals sources of firewood and food for direct consumption. Fukui to protect crops from wild animals had been developed by (1974: 133–138) mentioned that wild plants in fallow the swiddeners. Ishikawa (1983) reported that the territory forests and the surrounding environment were important for of swidden villages was determined by the availability of farmers practicing swidden agriculture as food, which labor who could participate in the hunting of wild boar in sometimes play a role as famine food. In Central and the Edo (1603–1868) and Meiji (1868–1912) eras. While a Northern Japan, swiddeners gathered nuts such as acorns variety of protective methods were employed, Nomoto and walnuts, while those in the western areas of Shikoku (1984: 162–185) categorized them into four main types. Island chose plants for which the subterranean part is The first two methods, namely, those depending on odor, edible, such as yam (Dioscorea spp.), Japanese dogtooth A review of studies on swidden agriculture in japan: cropping system and disappearing process 145 violet (Erythronium japonicum), Kuzu, and bracken World War II. While azuki bean was mostly cultivated in (Pteridium aquilinum supsp. japonicum). Swiddeners also the first year in traditional Japanese swidden systems before gathered wild vegetables, not only in times of famine, from World War II, it started instead to be widely cultivated in swidden fields such as young tree buds of udo and Japanese the second and third years and played a major role in such angelica tree (Aralia elata) and many kinds of wild grass, systems after the war. Buckwheat also turned out to be a such as giant butterbur (Petasites japonicus), Chinese garlic cash crop in the same way as azuki bean. In the Chichibu (Allium grayi), mioga ginger (Zingiber mioga), Japanese mountainous area, traditional swidden rotational systems, royal fern, bamboo shoots, and Japanese knotweed. in which Japanese barnyard millet, foxtail millet, soybean, Reports on non-commercial plants in swidden areas and azuki bean were cultivated, changed as a result of the are quite few, except for an illustrated reference book of commercialization of buckwheat. Traditional rotational flora from swidden areas in the Shiiba area (Saito and systems, including one-year cultivation of buckwheat, had Shiiba 1995). In this book, 173 plant species reported by changed into new rotational systems with its three-year only one informant, who was once a swiddener, are continuous cultivation. As this shows, the commerciali- described. Such in-depth knowledge of local plants and zation of traditional crops was one of the most important how to use them is considered to have been commonly factors to influence traditional rotational systems of shared among traditional mountainous villages of Japan. Japanese swidden agriculture. However, the infiltration of the market economy along As another important factor, in some cases, crops with improved accessibility of more remote areas induced cultivated on a small scale in the traditional systems, such the commercialization of forest resources such as timber, as Japanese rape, Japanese radish, and turnip, became more charcoal materials, and the cultivation of perennial important through the infiltration of the market economy. commercial crops; resulted in changes in the use of fallow In Japan, Japanese rape was mostly cultivated in paddy forests. fields after the harvesting of rice. While Japanese rape in In Japan, since the start of the Meiji era, the spread of swidden fields was cultivated on a small scale and was rare the market economy into mountain villages occurred and before World War II, it became a major commercial crop the cropping systems of swidden agriculture changed. The instead of traditional buckwheat and the most important total area of swidden agriculture decreased though specific crop after azuki bean after the war. On the other hand, physical conditions induced the expansion of swidden Japanese radish and turnip were cultivated on a small scale, agriculture in some particular areas (Mizoguchi 1986). The but they were among the major vegetable crops mixed- spread of the market economy was not uniform, and three cultivated in traditional swidden fields. On Shikoku Island, types of process of commercial crop introduction into maize and sweet potato were introduced at the end of the Japanese swidden systems occurred (Sasaki 1972: 124– Edo era and the beginning of the Meiji era (Yokokawa 155). In the first type, traditional crops became commercial 1955). In the process of commercialization of these crops, ones. In the second, new perennial commercial crops were cereal production in Japanese traditional swidden fields introduced and included in crop rotation of swidden gradually disappeared and only vegetable gardens agriculture. The third type involved swidden for remained. preparation for silviculture. The details of these three types In these cases, traditional rotational systems changed are provided below. into new types. In the case of the commercialization of traditional vegetable crops, traditional rotational systems Transformation of traditional annual crops into commercial disappeared and vegetable cultivation, which had been crops included in the traditional systems, was instead carried out In the first type of transition induced by the spread of independently. the market economy, annual crops, which had been Introduction of commercial perennial crops traditionally cultivated, became commercial crops and a new source of cash income. As mentioned above, the In the process of the introduction of commercial traditional basic crops of Japanese swidden agriculture were annual crops, the diversification of crops, changes in buckwheat, Japanese barnyard millet, foxtail millet, traditional rotational systems, a decrease in the importance soybean, and azuki bean. Among these five, azuki bean of swidden systems, and a shortening of fallow periods turned out to be the most popular cash crop (Sasaki 1972: along with the decline of cereal production occurred 96, Noda 1953). Traditional and newly introduced varieties simultaneously. With these changes, commercial annual were mixed-cultivated in swidden fields until the end of crops came to be cultivated throughout the cultivation 146 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al. period in swidden systems. On the other hand, the main five to six years of cultivation, the harvesting of tea was the characteristic associated with the introduction of main activity in swidden fields. commercial perennial crops was that these crops were The utilization of oriental paper bush and paper cultivated in both cultivation and fallow periods. mulberry (Broussonetia kazinoki × B. papyrifera) was also A major example of the introduction of a commercial important for swiddeners (Yokokawa 1955). At the end of perennial crop to Japanese swidden systems is that of the Edo era, paper mulberry was widely cultivated in mulberry (Sasaki 1972: 139–141). In Japan, sericulture had swidden systems. After the middle of the Meiji era, oriental been an important industry from the Edo era to the middle paper bush replaced paper mulberry (Sasaki 1972: 142– of the Shōwa era (1926–1989). In particular, the export of 155). The cultivation of paper mulberry was carried out on raw silk accounted for about half of the total export value a larger scale and more intensively than the cultivation of of Japan in the Taishō era (1912–1926). In swidden mulberry and wild tea as described above. The cultivation systems, mulberry was cultivated in northeast and central of oriental paper bush reached its peak during the period parts of mountainous areas in Japan, such as those of the from the end of the Meiji era to the early Taishō era (late Tohoku region, as well as Gifu, Toyama, Nagano, and 19th and early 20th century). After the early Shōwa era, the Shizuoka Prefectures. In Japanese swidden systems, cultivation continued only in the mountains of Shikoku mulberry was cultivated from the period of cereal Island, where almost 70 % of oriental paper bush cultivation cultivation to the fallow period, and swiddeners continued occurred, followed by the Chugoku Mountains. Oriental the harvest without a break. Mulberry production was paper bush was cultivated from the first year of swidden traditionally an important agricultural activity for farmers, systems with other annual crops in most cases. In a who cultivate leased land located far from their own land. documented case from Shikoku Island (Sōma 1956, Sōma In fact, the farmers carried out labor-intensive sericulture. 1959), oriental paper bush was cultivated from the second However, in contrast to the intensive sericulture in villages, or third year after the cultivation of annual crops such as the cultivation of mulberry was extensive. It was rare for foxtail millet, azuki bean, soybean, and maize. Oriental mulberry to be cultivated in the main fields of the farmers, paper bush started to be harvested from the winter of the and it was instead generally cultivated in more peripheral second year of cultivation to the spring of the third year, mountainous areas. When farmers cultivated mulberry in and annually thereafter. However, oriental paper bush their main fields, the fields were not permanently used for cultivation changed as a result of the implementation of this purpose, but rather were used after cereal production. systems aiming at achieving high productivity, from It is known that the suitability of mountainous land for composite swidden systems to specific systems for oriental mulberry cultivation partly determined whether the paper bush cultivation, or systems with silviculture. cultivation of mulberry is economically profitable or not. The peaks of the cultivation of the above perennial Another illustrative example is wild tea (Camellia crops were over by the 1920s and 1930s. Although the sinensis) cultivation. The date and route of introduction of cultivation of these crops sometimes expanded in response wild tea into Japan are unclear, but it was one of the most to market prices, most commercial perennial crops in important tree crops in Japan for a long time. Wild tea Japanese swidden agriculture had decreased or disappeared cultivation in Japanese swidden systems was carried out by the middle of Shōwa era (the 1960s). mainly in the west and southwest of the country (ibid.: Introduction of silviculture into swidden rotational systems 141–155). At the end of the Edo era and the early stages of the Meiji era, wild tea cultivation in swidden systems was In Japan, since silviculture developed greatly after the widely practiced, but it then diminished because of the end of World War II, many swidden agriculture systems development of plantations of Japanese cedar, Japanese shifted to those that were preparatory for silviculture. The cypress, and pines, as well as sericulture and the tree species in the new systems were mostly Japanese cedar, development of the tea industry after the middle of the Japanese cypress, and pines. As mentioned above, forests Meiji era. Commercial cultivation of wild tea continued near mountainous villages started to be utilized for only in some areas of Kochi Prefecture and the mountains commercial production. Even after the interference of of Kyushu Island. One of the major characteristics of wild government became stronger and the administrative sizes of tea cultivation in these areas was a close association with village areas were reorganized, swiddeners utilized forests swidden agriculture systems. In these areas, tea grew wild without special restriction (Fujita 1975: 195–202). In without any special management, and flourished after two particular, the development of silviculture enabled to three years of cultivation in many swidden fields. After swiddeners to utilize forests commercially for a long time A review of studies on swidden agriculture in japan: cropping system and disappearing process 147 by large-scale investment. The combination of swidden of millet and daily life utilization of millet will be reviewed agriculture and silviculture led to the development of a new with a focus on the crops cultivated in swidden agriculture, type of swidden agriculture. In this type, swiddeners were noting that many different kinds of millet were cultivated in able to utilize swidden systems continuously, including the swidden agriculture practiced across Japan. From the during cultivation and fallow periods. Accordingly, the perspective of daily life, the use of fuel wood and wood to cultivation period started to play an important role as a be used for charcoal production acquired from secondary preparatory stage prior to the following silviculture. forests grown on swidden fields is an important topic to be Meanwhile, it should be considered that a lot of swiddeners addressed. This topic is important as the energy resources maintained subsistence farming at that time because crop available in Japanese mountain villages were limited to rotations and basic crops in the cultivation period remained firewood and charcoal before oil, gas, and related energy nearly unchanged and they had always been cultivated with sources were available for use. However, a literature search trees. These crops were still important for their livelihood. by the authors revealed no previous papers on logging of In such systems, short-term cultivation before planting secondary forests grown on swidden fields for the trees also had certain advantages, such as saving effort acquisition of firewood and wood to be used for charcoal required for plowing and weeding, as well as accelerating production. Therefore, discussions in this section will be tree growth at initial stages. For example, in Shizuoka limited to daily-life utilization of crops cultivated from Prefecture, it was reported that 80% of the cost for plowing swidden agriculture. and weeding in swidden fields could be saved by short-term From harvest to polishing of millet cultivation beforehand. Therefore, this type of swidden agriculture appeared to have two advantages: one is that the The main staples of swiddeners consisted of several entire period of swidden agriculture could be utilized kinds of cereal crop, including Japanese barnyard millet, productively and the other is that a smooth shift to foxtail millet, and finger millet. Among these types of silviculture could be achieved. In addition to this, this type millet, Japanese barnyard millet played the most important of swidden agriculture had another merit from the role in the daily diet of peoples in mountain villages landowners' viewpoint: they could mobilize the cheap labor (Tachibana 1995: 274–322, Ema 1996: 421–435, Shizuoka necessary for planting trees in return for the permission for City Toro Museum 1997: 12–21, Fukui 1974: 123–132). poor peasants to cultivate there in the first few years. Tachibana (1995: 152–243) recorded the entire process Sasaki (1972: 146–155) pointed out that this type of from harvesting to the storage of Japanese barnyard millet swidden agriculture essentially included two contradictory in the Shiramine area, Ishikawa Prefecture, as follows. This systems, that is, land use for silviculture and that for case study indicated that people had established intensive agricultural production. Consequently, there were many methods of millet processing and had managed to store conflicts in terms of forest land use management between grain as insurance against a poor harvest and famine, in swiddeners and landowners. The development of accordance with local knowledge and traditions. silviculture in this system led to the expansion of the area Harvesting of forest plantations and a simultaneous reduction in the swidden area; eventually, land use for silviculture limited In early October, people harvested Japanese barnyard swidden agricultural production. While Japanese swidden millet using a small sickle and/or various equipment made agriculture had played composite roles in traditional of bamboo, wood, and bark, as well as iron tools, broken systems, each role such as crop production or silviculture in pieces of ceramic cups and dishes, and used razors. After the systems developed as independent agricultural system picking, panicles were stored in small baskets made of stalk through the infiltration of market economy. and bark of maple. Then, the panicles were gathered into large containers. At harvesting, people had to pick all the panicles, even though they had not fully matured, in order SWIDDEN AGRICULTURE AND to prevent damage by frost and snow. EVERYDAY LIFE Drying

The above sections discussed the natural environment In the drying step, people adopted two methods to dry in which swidden agriculture was practiced, the crops the harvested panicles: an outdoor sun-drying method and cultivated in swidden agriculture, and the cropping systems an indoor fire-drying method. The average harvest of millet adopted in swidden agriculture. In this section, harvesting per household was 2,430 liters in total, including 1,800 148 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al. liters of Japanese barnyard millet, 450 liters of foxtail maintained for more than ten years. The glumes were used millet, and 180 liters of finger millet. However, they as a packing material of potatoes in a storehouse to keep typically had only 20 days before the ground was covered them warm, and also as fertilizer after burning. with frost. Using the outdoor method, it was difficult to dry Polishing a large amount of panicles within 20 days in cold weather conditions. Therefore, people developed particular People engaged in the polishing step two times a year: techniques indoors to dry the panicles completely in a short in late November and mid-April. In the first step, they period. ground grains using a stone mortar to remove the palea and The indoor methods were undertaken mainly using an the lemma of the grain. Then, they repeated sifting and open hearth set into the floor of the main house as a source grinding two to three times. Finally, the grain was divided of heat. People used several sites to spread out the panicles: into three parts: endosperm, mixture of embryo and broken the attic, beams, hanging boxes, and wood-framed stands. endosperm, and bran. However, the volume of the harvest In some households, the hearth was prepared in a hole in decreased during this process. The volume of endosperm the floor, and a wooden stand was set over the hole on compared with that of all the grain was only 35 to 40 %. which to spread out the panicles. People chose the most Therefore, the mixture and bran were used as food in years effective way depending on the structure of the house and with a poor harvest. the location of the hearth. They also took great care to Daily meals ensure that the fire was kept under control, as the alternative could result in the fire reducing the house to ashes. The eating habits of swiddeners were characterized by Therefore, a special drying hut, separate from the main a large number of meals per day. In the Shiramine area house, was sometimes prepared and operated by private (Tachibana 1995: 471–473), people usually had three meals owners or by the community. a day, breakfast, lunch, and dinner, and added three or four Indoor drying methods had another advantage. In the light meals and snacks between the basic meals during subsequent threshing step, panicles that had been heated on periods of hard work. On the other hand, people in the a wooden stand were easily dehusked compared with those Hida area, Gifu Prefecture, had six meals a day in winter not subjected to this treatment. In other words, the steam (Ema 1996: 89–99). This included breakfast at 4:00, a light from wet panicles partially boiled the grain, having a meal at 9:00, lunch at 11:00, light meals at 12:00 and 15:00, similar effect to the parboiling of rice as prepared in India. and dinner at 18:00. Furthermore, a bedtime snack was added for those who stayed up late working in summer. Threshing This tradition was due to the characteristics of boiled Soon after the drying step, people engaged in grain of Japanese barnyard millet as a main staple. As threshing. They sometimes stayed up until dawn to Tachibana (1995: 471–473) indicated, this boiled grain is complete it within a single night because the heated dry and difficult to eat in large quantities, as well as being panicles could be easily dehusked while they were hot. easy to digest. Therefore, people had to take many meals a There were also indoor and outdoor threshing day. methods. In the case of the indoor methods, people used The cooking processes of the three major millets, tools such as a wooden large mortar or a wooden mallet, or Japanese barnyard millet, foxtail millet, and finger millet, mats and wooden sticks to thresh. After the first threshing are indicated below, on the basis of a case study on the treatment, they picked out untreated panicles and threshed Shiramine area (ibid.: 431–470). them again. Then, they separated the grains from outer Japanese barnyard millet glumes by means of current of air. On the other hand, in the case of the outdoor methods, people hit panicles on a Grain of Japanese barnyard millet was crushed into mat using wooden sticks. They then threw the panicles and small pieces using a large stone mortar in the polishing grain at a wooden board leant against the wall of a house. process. Therefore, people used minced grain, not whole When the threshing was complete, the panicles were grain, to prepare food such as boiled grain, porridge, divided into four parts: rachis branch, mature grain, dumplings, pounded cakes, thick soup, roasted grain, and immature grain, and glumes. The grain was then packed in alcoholic drinks. The three types of minced grain are containers made of stalks and kept in a storehouse with adapted to each method, namely, the rough type for boiled wooden labels indicating the year of harvest. In cases when grain, the intermediate type for dumplings, roasted grain, the grain was completely dried, its quality could be and thick soup, and the fine type for porridge, pounded A review of studies on swidden agriculture in japan: cropping system and disappearing process 149 cakes, and alcoholic drinks. glutinous foxtail millet. In the case of non-glutinous foxtail Boiled grain of Japanese barnyard millet played a key millet, it was cooked into boiled grain, dumplings, and role as a main dish. Two kinds of boiled grain were cooked: roasted grain. one consisted of endosperm of polished grain alone and the Finger millet other consisted of endosperm, a mixture of embryo and broken endosperm, and bran. The texture and digestible- Finger millet was mainly used after being pounded ness of the latter depended on the degree of polishing and into a powder. The powder was stickier than that of the combination of ingredients. In addition, the cooking Japanese barnyard millet and was suitable for cooking. The skill of the person, typically a woman, producing the food major types of food made from the powder were dumplings, affected the taste of the latter. She had to have good timing baked powder, pounded cake, thick soup, and candy. The in terms of stopping the heating and stirring the grain using dumplings were used as one of the ingredients of porridge a wooden scoop. Thus, the stirring of grain was significant and miso soup, as well as special food for Buddhist in the finishing step, after the whole process of cultivation, ceremonies and annual events. The baked powder or iriko harvesting, threshing, polishing, and cooking. This placed was eaten as convenient food for light meals. For this, a an emphasis on the role of the woman in taking charge of small amount of powder was placed into wooden balls and this finishing step. Accordingly, the wooden scoop became mixed with boiling liquid, such as hot water, miso soup, or the symbol of the position of the woman. This was the tea. origin of the“ wooden scoop succession ceremony” in the In addition to the three types of millet, other cereal Shiramine area. This memorial ceremony was held by crops were used as staples. In the case of the Tsubayama household members on the sixth day after the death of the area (Fukui 1974: 123–129), common millet (Panicum woman of the house. It was an occasion in which a young miliaceum) and sorghum (Sorghum bicolor) were cooked woman adopted this position of responsibility and started to into mochi cakes. Maize was pounded into rice grain-sized lead the housework of the household. pieces and boiled. Buckwheat was cooked into noodles. A similar case was reported in the Hida area (Ema Light meals 1996: 421–435). The homemaker had to cook four types of boiled grain: 1) boiled rice for ceremonies and rituals, 2) The dietary habits of the swiddeners were quantita- boiled grain of rice and Japanese barnyard millet, 3) boiled tively and qualitatively supported by a variety of food grain of Japanese barnyard millet, and 4) boiled grain and materials obtained from agricultural, hunting, and gathering bran of Japanese barnyard millet. In addition, the activities (Nomoto 1984: 66–70). These materials were homemaker had to provide appropriate types of boiled grain necessary to achieve a well-balanced diet and served as to each household member by using a wooden scoop to light meals and dishes with millet. control the annual consumption. Therefore, the homemaker Light meals were taken several times a day, in addition had great power as the food manager of the household, and to basic meals. In the case of domesticated plants, potato this power was represented by the wooden scoop. When (Solanum tuberosum), sweet potato, and pumpkin were the wooden scoop was handed to a young homemaker after cooked for light meals in the Shiramine area (Tachibana the death of an older one, this power was also transferred. 1995: 471–473) and Hida (Ema 1996: 89–99). Wild plants that bore nuts, roots, and tubers were gathered from the Foxtail millet surrounding area and used as supplementary food (Nomoto Foxtail millet was the second major cereal next to 1984: 128–140, Nomoto 2005: 13–15, Saito and Shiiba Japanese barnyard millet. There are two types of 1995: 9–48). The nuts included 1) oak, 2) Japanese endosperm starch of foxtail millet: non-glutinous and chestnut (Castanea crenata), and 3) tochinoki. The roots glutinous, while varieties of Japanese barnyard millet and and tubers consisted of 1) lily species such as uba-yuri finger millet have only one type: non-glutinous starch. (Cardiocrinum cordatum), ko-oni-yuri (Lilium leichtlinii Glutinous foxtail millet played a significant role as a var. maximowiczii), naruko-yuri (Polygonatum falcatum), food material for events, such as offerings to the gods and and tsurubo (Scilla scilloides), 2) species of Amaryllidaceae special food for Buddhist ceremonies. It became awa- such as kitsune-no-kamisori (Lycoris sanguinea), and mochi after being steamed and ground into a paste with a higan-bana (Lycoris radiata), 3) kuzu, 4) tokoro yam wooden pestle. Glutinous rice played this role in areas of (Dioscorea tokoro), and 5) warabi. Some of these types of paddy cultivation in lowland Japan, taking the name mochi. wild food contain toxic components. Therefore, people However, in the Shiramine area, the word mochi referred to developed particular methods of detoxification in order to 150 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al.

Table 7. Wild plants used as foods served with cereals

Scientific name Family Japanese English Tsubayama area1 Allium grayi Alliaceae nobiru Chinese garlic Equisetum arvense Equisetaceae tsukushi field horsetail Eutrema wasabi Brassicaceae wasabi Japanese horseradish Oenanthe javanica Apiaceae seri oriental celery Osmunda japonica Osmundaceae zenmai Patrinia villosa Caprifoliaceae otokoeshi Petasites japonicus Asteraceae fuki Japanese butterbur Fallopia japonica Polygonaceae itadori Japanese knotweed Zingiber mioga Zingiberaceae myoga mioga ginger Shiiba area2 Allium grayi Alliaceae nobiru Chinese garlic Aralia cordata Araliaceae udo Aralia elata Araliaceae taranoki angelica tree Clerodendrum trichotomum Lamiaceae kusagi Conandron ramondioides Gesneriaceae iwatabako Crassocephalum crepidioides Asteraceae benibana-borogiku Cirsium suffultum Asteraceae tsukushi-azami Eutrema wasabi Brassicaceae wasabi Japanese horseradish Glycyrrhiza uralensis Fabaceae kanzo Pseudognaphalium affine Asteraceae hahakogusa Helwingia japonica Helwingiaceae hanaikada Hosta sp. Asparagaceae giboushi plantain lily Oenanthe javanica Apiaceae seri oriental celery Osmunda japonica Osmundaceae zenmai Japanese royal fern Patrinia villosa Caprifoliaceae otokoeshi Petasites japonicus Asteraceae fuki Japanese butterbur Fallopia japonica Polygonaceae itadori Japanese knotweed Pteridium aquilinum supsp. japonicum Dennstaedtiaceae warabi Rumex acetosa Polygonaceae suiba sorrel Sasa borealis Poaceae suzutake Smilax riparia Smilacaceae shiode Wisteria floribunda Fabaceae fuji Japanese wistaria 1 Fukui (1974) 2 Saito and Shiiba (1995) consume them safely. berries were used as sweets: nashi pear (Pyrus pyrifolia), and Japanese persimmon (Diospyros kaki) (ibid.: 104–106, Food served with millet 320). For meals, several kinds of basic dish were served Animal protein and fat were obtained mainly from with millet (Tachibana 1995: 333–341, Ema 1996: 89–99, wild animals by hunting, fishing, and gathering (ibid.: 68– 462–467). They included 1) vegetables flavored with 70, 140–148). The target mammals were boar, bear, deer, certain ingredients, ae-mono, 2) vegetables boiled in broth, Japanese serow, and rabbit. Birds, freshwater fish, and ni-mono, 3) vegetables preserved in salt, tsuke-mono, and 4) insects were also gathered. Honey from wild bees (Apis soups, shiru-mono. The most important crop vegetable to japonica) was gathered from artificial beehives and used as be cooked in these dishes was Japanese radish. Moreover, a sweetener and a medicine. leaves and young buds of various wild plants and bamboo shoots were cooked frequently (Table 7). Plant oils were also obtained from sesame (Sesamum CONCLUSION indicum), yegoma (Tachibana 1995: 394–396), and tea fruit (Nomoto 1984: 67–68). Several kinds of wild fruit and The present paper reviewed some of the major study A review of studies on swidden agriculture in japan: cropping system and disappearing process 151 results published in Japanese on swidden agriculture which However, in the 1970s, swidden agriculture which had was once practiced in Japan. In this review, a focus was been continuously practiced as a primary means of placed on the natural environment in which swidden subsistence in mountainous areas of Japan ceased to exist. agriculture was practiced, cropping systems, crop The disappearance of Japanese swidden agriculture was cultivation in swidden fields, the transition of swidden caused by intricately intertwined reasons such as agriculture at the end of the disappearing stage, and the penetration of the market economy into the mountainous utilization of millet cultivated in swidden agriculture. areas, expansive reforestation introduced as a part of the Swidden agriculture of temperate Japan featured postwar reconstruction, aging and depopulation in the cultivation primarily of millet. Furthermore, Japanese mountainous local communities, and the modernization of swidden agriculture was characterized by highly mountain land governance. It is said that the reasons of sophisticated and complex cropping systems according to disappearing swidden agriculture differs from region to the natural environment, which varied from one region to region. another. The largest determining factor for the choice of In Toyone Village, Aichi Prefecture, where swidden cropping system was the timing of burning. Distinctive wet agriculture used to be practiced, swidden agriculture as a and dry seasons exist in the regions affected by Southeast subsistence activity was replaced by agriculture to produce Asia's tropical monsoons, though no air temperature mulberry, an economic crop; additionally, forest land which restrictions exist on cropping calendar. As a result, crop had been covered by miscellaneous trees and had been used cultivation is possible only in the wet season. This seasonal for swidden agriculture was replaced by sites for charcoal pattern limits the timing of burning only to the period production (Fujita 1992: 243–244). In both cases, Fujita immediately before the onset of the wet season in Southeast (1992) claims that the sites for swidden agriculture were Asia. Also, since it is often assumed that Borneo is not converted to sites for cash crop production and swiddeners seen distinctive wet and dry seasons, dry spell with little were employed for the cash crop production, that is, they rain is existed around August. Swiddeners in Borneo, adopted cash earning as their new means of subsistence. therefore, burn their fields within that time frame The decline of swidden agriculture was aggravated by (Kendawang et al. 2005). For the case of Japan, the timing artificial forest planting which shifted into high gear in the of burning was more flexible than for the case of Southeast Shōwa era. Swidden fallow lands were well-suited for Asia and specifically occurred in the period extending from artificial tree plantation, thus, the declining swidden April to July. Major concerns of swiddeners are the agriculture could only serve as a preliminary step for it. In effectiveness of burning on weed and insect control when the mid-1950s, the price of lumber soared due to the they decide its timing. This flexibility is the fundamental increased demand caused by the rapid growth of Japanese conditions of diversity of cropping systems of swidden economy. In addition, in the second half of the 1950s, as a agriculture in Japan. result of the shift in energy resources, firewood and Adoption of weed and insect controls well-suited for charcoal, which played the leading roles as fuels for a long local environmental conditions allowed continuous time, were replaced by fossil fuels. As such, in many of the cropping over a period of several years in Japanese swidden areas of swidden agriculture where firewood and charcoal agriculture. In swidden fields of Japan, a variety of millet were produced, stands of broadleaf trees, which were used such as foxtail millet, finger millet, Japanese barnyard for wood and charcoal production, were converted into millet, and buckwheat were mainly cultivated. In the first stands of coniferous trees, which were used for building and second years of swidden cultivation, crops which materials. require a large amount of nutrients were cultivated, Fujita (1981: 234–235), who examined the relationship including foxtail millet, Japanese barnyard millet, and between swidden agriculture and expansive reforestation, buckwheat. Subsequently, leguminous crops such as discussed that swidden fields were converted smoothly into soybeans and azuki beans, which are capable of fixing coniferous forests in some areas while this was not the case nitrogen, were cultivated. These practices suggest that in other areas. The areas which smoothly underwent this Japanese swidden cultivation aimed at maximizing the conversion were located in regions such as Shikoku and overall production through an appropriate combination of Central Kyushu, where swidden agriculture was practiced several crops and growing them in a proper order. Thus, across broad areas. The successful conversion was founded swidden agriculture in Japan had emphasized continuous upon the cohesive strength within village communities cropping for several years over maximum harvest in a created by previously practiced swidden agriculture as well single year. as the ease of securing the areas required for expansive 152 TROPICS Vol. 22 (4) Satoshi Yokoyama, Isao Hirota et al. reforestation, both of which served as the underlying relegated to only a few limited areas of Southeast Asia is driving forces realizing the dramatic conversion of the not difficult”. It is the authors' hope that the results of swidden fields into forested areas. In contrast, the above- studies on Japanese swidden agriculture conducted up to mentioned conversion was achieved smoothly neither in the date will be incorporated into studies of swidden agriculture Chugoku Mountains nor the Kitakami Mountains. For the in the tropics as much as possible and that such an approach case of the Chugoku Mountains, instead of being engaged will lead to a proper understanding of swidden agriculture with conversions of swidden fields, the population in the at present and future. area flowed out of their villages due to the migration of Since the present paper reviewed previous studies families, resulting in a lack of work force. Namely, the primarily on the natural environment and crop cultivation mountainous areas had difficulty in continuing swidden associated with swidden agriculture, regarding swiddeners' agriculture because of depopulation. For the case of the lives, only their utilization of millet, one of major crops Kitakami Mountains, forest holders set out to reclaim lands cultivated in swidden agriculture was discussed. In Japan, to be used for paddy fields and became engaged with studies on swiddeners from early modern times and the livestock farming and were less engaged with expansive subsequent periods have been accumulated in the fields of reforestation. history and historical geography. In addition to this, studies The role played by the authority of the state in ending on changing socioeconomic conditions surrounding swidden agriculture is discussed by Ichikawa and Saito swidden agriculture have been also carried out in Japan. (1985: 52), specifically, in relation to police forces and However, because of the limited space, these studies were regulations of burning fields and forests in Kisodani area of not introduced in the present paper. These topics will be Nagano Prefecture. According to Ichikawa and Saito addressed in the future in the form of a discussion in (1985), swidden agriculture started declining in mountain another manuscript. villages during the late 1890s to mid-1900s not only because of economic development but also due to the ACKNOWLEDGEMENTS This study was conducted strengthening of regulations on agricultural fires reinforced as part of the research project“ A cultural ecological study by police forces. Particularly in towns and villages in of‘ swidden on the verge of vanishing’ in Southeast Asia which forests owned by the Imperial Family and (Leader: Satoshi Yokoyama)” by the International Program government forests were located, burning was allegedly no of Southeast Asian Collaborative Research in 2010, Center longer allowed without permission as a result of strict for Southeast Asian Studies, Kyoto University. In advancing regulations set by the Imperial Forestry Bureau of the the present study, the authors have received advice and Imperial Household Agency. guidance from Dr. Kanʼichi Nomoto, Dr. Sadao Sakamoto, Thus, the circumstances in Japan which drove swidden and Dr. Taisaku Komeie. The authors wish to express their agriculture to extinction are something similar to those in gratitude to these three scholars. Southeast Asia which are currently causing its swidden agriculture to disappear. In fact, in Southeast Asia, conversion of tree species has also been occurring as a REFERENCE result of reforestation, and the cultivation area of cash crops has been expanding (Padoch et al. 2007). In mainland Aoba T. 1993. Nihon no yasai (Japanese vegetables). Yasaka Southeast Asia, the area covered by Para rubber trees has Shobō, Tokyo. [in Japanese] expanded rapidly (Guo et al. 2002). Specifically, in Egashira H. 2007a. 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