Tanada means a rice-producing area located on a slope. A group of small rice fields regularly assembled on a steep slope, all of which can be seen at a glance, are also called Senmai-da, or thousand rice fields. Tanada is called rice terraces in English.
Tanada in Japan
Tanada in Nishihata-cho, Ikoma City. A scene of cultivation in this area. You can see a rotary tiller in the distance, working on a small, long and thin rice field.
In Japan, well-drained lands with good water supply are the best places for rice cropping. All land is inherently sloping, but lands where the slope is too gentle or where drainage is not good are not appropriate for rice cropping because they become moist. In addition, lands have to be sloping to some extent in order to be irrigable, so alluvial plains in the lower reach of rivers, where the slope is gentle, were not appropriate for rice cropping before the Edo period. That is, before the modern times the best places for rice cropping were sloping lands, such as ones on diluvial plateaus and stream terraces in terms of landform, or basins and midstream sites in terms of classification of plains, and generally a group of farmers established an irrigation facility and built Tanada there.
Irrigation technology has improved so much since the modern times that irrigation and drainage can be made possible by building a waterwheel along the channel even on alluvial plains where the slope is gentle, and as a result, rice cultivation has spread to downstream plains which are called breadbaskets today.
In the Edo period, as many domains in western Japan were small and had narrow alluvial plains, they developed rice fields even in the mountains in order to increase Kokudaka (assessed yield) which was the economic base of the domain, and a large number of rice terraces (on steep slopes), which are called Tanada today, were developed. At that time, dikes and mounds of Tanada were made of stone walls which could bear steepness of the slope, for the purpose of increasing yield to the maximum. On the other hand, there was little economic incentive for making Tanada (on a steep slope) in eastern Japan where most domains were large, so they rarely made Tanada, and when they did, dikes and mounds were mild land elevations and the sights of Tanada were quite different from those in western Japan.
(In the Tohoku and Hokuriku regions, due to the availability of meltwater, cultivable lands were made even larger if the temperature in the summer was appropriate.)
As the best place for building a fishing port was often a cove surrounded by coastal mountains, in some fishing villages which lost a contest for ownership of flatlands far from fishing ports, Tanada was made in the mountain near the port for the purpose of securing the fisherfolk's staple food, both in eastern and western Japan.
(In the case of the Tsushima Domain, lands appropriate for cropping were so scarce that they had to import rice from Yi Dynasty Korea.)
As rice cultivation has become more massive and mechanized since the end of the World War II, agricultural fields, each of which used to be shaped differently according to the slope, were improved and unified into large rectangles in which it is easier to introduce farm machines. Unification of agricultural fields and mechanization as stated above were difficult in Tanada (on a steep slope), but many rice terraces in the mountains were successfully enlarged thanks to the development of civil engineering technology. However, in the case of Tanada (on a steep slope) in western Japan, the slope would have to be cut away on a large scale if agricultural fields were to be enlarged, and ancillary works including prevention of mudslides on the slope would involve enormous cost, so many of the rice terraces were not enlarged, or were abandoned and degraded.
Of course irrigation facilities were established on the remaining Tanada (on a steep slope) because irrigation is essential for rice cropping. But Tanada were in the mountains, and were often located upstream of a river; as a result, in the case of a long spell of dry weather, the amount of water quickly decreased and the rice paddies dried up. Thus rain-fed irrigation was conducted either by extending canals to rivers other than the nearest one or by building irrigation ponds. In areas where such measures were not feasible, a horizontal tunnel was sometimes built under the rice field in order to utilize recharged groundwater such as sump and subsoil water.
Definition of Tanada
As stated in the preceding paragraph, all the rice fields before the modern times were Tanada, so historically there was no distinction between 'Tanada' and 'rice paddies.'
The word "Tanada" was mentioned in Koyasan Bunsho written in 1338, which recorded the yield and marking off of Tanada in units of "tan" in Shibutasho, Ito County, Kii Province (today's Katsuragi-cho, Wakayama Prefecture), in a sentence "棚田一反御得分四十歩ハ."
(Society of Tanada)
Ancient structural remnants of Tanada in the latter part of the Kofun period (the middle of the 6th century) were discovered in Numata City, Gunma Prefecture.
Recognition System of the Ministry of Agriculture, Forestry and Fisheries of Japan
At present 'Tanada' means 'rice fields arranged in a staircase pattern on a very steep slope on a mountain.'
Thus the MAFF defines Tanada on the basis of steepness of the slope, and there are no provisions on the degree of mechanization or on agricultural culture.
Definition used by the MAFF
Rice fields with a gradient of more than 1/20 (a slope which is elevated more than one meter per horizontal length of 20 meters) are recognized as 'Tanada.'
If a rice field is recognized as 'Tanada,' a subsidy will be offered.
According to the field survey conducted by the MAFF and Japan Soil Association in 1993, the total area of 'Tanada,' as defined by the MAFF, was 221,067 hectares. This hectarage accounted for about 8% of the total area of rice paddies at that time, which means Tanada was quite a common form of rice paddies. However, 12% of the Tanada had already been abandoned at that time.
High-value added tanada
In many cases, high-value added commercial crops such as wasabi (Japanese horseradish) are grown in Tanada, due to its high drainage capacity. Some rices are turned into a brand by publicity activities which focus on the fact that the rices are produced in Tanada.
In many regions, an owner system has been introduced for the purpose of conserving the landscape or fostering repeaters from the standpoint of tourist spots. Such a system is prescribed in the Act on Promotion of Development of Community Farms and the Act on Special Provision of the Farmland Act, etc. in Relation to Lease of Specified Farmland. An 'owner' is time-bound, so farmers are not turned into tenants. It is against the Agricultural Land Act that persons other than farmers should acquire any agricultural lands, so being an 'owner' is merely nominal and does not involve real-estate transactions. That is, an 'owner system' is an option transaction in which, for farm families, secondary income is increased and risk hedge is achieved.
Farming characteristics of tanada
Ownership of each agricultural area was organized at the time of enlargement and improvement of agricultural areas in plains, but there was no such organization in the case of Tanada, so the ownership relationships of Tanada, which look uninterrupted to outsiders, are quite complex and the area cultivated by each household is small. As a result, it costs farmers too much to introduce agricultural machines and they are often forced into having another job in order to continue farming. There are two types of dual-occupation cases; cases where the 'head of a family' holds dual occupations and cases where the 'family' holds dual occupations, and in the latter cases the head of a family who has know-how for farming is engaged in agriculture and the other members including his/her children and grandchildren gain an income from another occupation. In these cases farmers cannot pass on their agricultural know-how to their children or grandchildren, so no generation change in farming occurs, farmers grow older and at last they give up farming. In cases where the family holds dual occupations, the possibility of abandonment of farming is relatively low, because the method of agricultural management and household know-how are passed on to successors in the course of operating farming.
Tanada has so small a cultivated area that it is difficult to introduce 'large' agricultural machines. However, it is possible to introduce 'small' agricultural machines by building roads to or between rice terraces. Generally, 'small' machines, which are less effective, are more difficult to share because every farmer in a village starts the same farm operation at the same time. In the case of Tanada, however, the timing of farm operations differs slightly between the upper part and the lower part of a mountain, so it is easier to share agricultural machines than in lowland villages. Previously agricultural cooperatives (financial sector) were encouraging the introduction of agricultural machines to individual households for the purpose of increasing the amount of loan outstanding, but they have begun to shift their lending to collective ownership of machines which accompanies less credit risk, and such a shift is bringing about a change in the agricultural system in connection with Tanada.
Tanada throughout the world
Cultivated fields very similar to Tanada can be seen in almost all the rice-cropping mountains around the world. Rice terraces in Yunnan Province of China, Vietnam, the Kingdom of Thailand, Nepal, Indonesia and Philippines are especially well-known.
Furthermore, Tanada located in the central mountainous region of the Philippines (the Luzon Island) are said to be the largest in the world. This region was designated a World Heritage Site (cultural heritage) by the United Nations Educational, Scientific and Cultural Organization in 1995, as a group of rice terraces of the Philippine Cordilleras.
The 100 best rice terraces in Japan
The Ministry of Agriculture, Forestry and Fisheries selected the 100 best rice terraces in Japan for the purpose of promoting tourism, because the ministry determined that it was difficult to maintain rice terraces only through agricultural revenues and dual occupations. The 100 best, which was published on July 16, 1999, includes Tanada in 134 areas of 117 municipalities all over Japan.
The 100 best includes rice fields which look very like 'Tanada,' being located on a slope steeper than one twentieth, so it is expected that the Japanese traditional method of agricultural management is inherited in those rice fields, but actually mechanization is under way.
However, selected as a 'tourist spot,' the farming villages have been transformed into a venue for traditional agricultural experiences such as rice transplanting and harvesting, or a venue for 'green tourism.'
Of all the rice terraces built with mounds of earth, the number of rice paddies which are currently cultivated is 375. They were established by a nonprofit organization (NPO) called Oyama senmaida hozonkai (Oyama senmaida preservation society) in 1997. A large number of city-dwellers have become members of the NPO or owners of Tanada. The NPO is actively involved in various activities including production of tofu (bean curd) and miso (soybean paste). These rice paddies are designated for cultural landscape conservation and utilization activities by the Agency for Cultural Affairs.
The 'sake-making owner project,' in which the participants planted rice for brewing sake in Tanada, was started on April 23, 2006. About 180 people registered as participants this year. This is the third year of the project. People who wish to preserve Tanada, including city-dwellers and local farmers, planted rice in the fields. Seedlings are made into refined sake called 'Tanada no mai' (Dance in the rice terrace) by a brewery called 'Fusa no mai' (Dance of Bunches) and provided to the owners. The owners deepen exchanges through rice transplanting, mowing, harvesting, production of guinomi (Japanese sake cup) and a tour of the sake brewery.
Kiwa Town, Minamimuro County until the consolidation in November, 2005. 810 abandoned rice fields (2.4 hectares) have been restored in the restoration project since 1993. The number of rice terraces, including 530 rice fields cultivated by local farmers (4.6 hectares), total to 1,340 (7 hectares). Built with stone walls, these rice terraces have as many as 100 steps. They are on a very steep slope with a gradient of 1/4 (a one-meter elevation per four meters of horizontal length; about 14 degrees) and the difference of elevation between the highest rice field and the lowest one is no less than 100 m. It is said that there were 2,240 rice fields according to a cadastral register prepared in 1601. Senmaida hozonkai organized by the residents of Maruyama Village and Kiwa Furusato Kosha are engaged in maintenance and management of Tanada. There are 33 households in Maruyama Village. The residents' average age is about 70 years old. The villagers, members of Senmaida hozonkai and owners of Tanada (517 people in 113 groups) participate in agricultural tasks.
Fukano (Matsuzaka City)
The total extension of the stone wall built with about three million stones is approximately 120 km.
It is called an 'artwork of stone.'