Photos

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Hani and Yi technique of irrigation has always been a secret since their rice terraced fields were built from mountain top to deep valley. Many friends also wrote me asking for the Hani & Yi method of rice cultivation but not until recently I was lucky to locate a valuable field survey by Adachi Shimpei. I hope his work helpful to all of us who are willing to learn.

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Terraced Rice Cultivation

Along the slopes of the Ailao Mountains in Yunnan Province, Southwest China, ethnic groups such as the Hani and Yi have developed an impressive landscape of terraced paddy fields over the past several hundred years. Their intensive terraced rice cultivation stands in striking contrast to shifting cultivation, the predominant mode of agriculture in tropical mountain areas. This study aims to clarify how terraced rice cultivation has been developed and sustained over many years in the Ailao Mountains from the viewpoint of agricultural technology.

In terraced rice cultivation, considerable effort is paid to the preservation of paddy fields. In the dry season, most of the terraced paddy fields are kept inundated even when no crop is grown. This dry season irrigation helps to prevent the collapse of the terrace, in close relationship with various farming works. The long-distance channel irrigation systems maintained by local groups have secured a dry season water supply. In the wet season, on the other hand, protection of paddy fields from excess water is the major concern. Many kinds of drainage facilities can be observed both in the irrigation channel and in the terraced paddy field.

Irrigation in terraced rice cultivation is designed not only for supplying water to rice plants but has various other purposes as well. In addition to the protection of terraced paddy fields, the unique practice of year-round irrigation plays many important roles, including storing water, maintaining favorable soil conditions for rice growth and providing a habitat for various edible aquatic animals.

In conclusion, the terraced rice cultivation in the Ailao Mountains has been sustained by various types of technology, related in particular to irrigation and drainage, which have special bearing in the terraced paddy field.

Thanks to intensive terraced rice cultivation, people have formed and maintained communities of relatively high population density, even in a mountainous area. This stands in striking contrast to low-population density societies based on shifting cultivation, which are predominant in tropical mountain areas.

In order to sustain agricultural activities on the steep mountain slopes, it is important to preserve the farmland itself, as well as maintaining the productivity of the land. Agricultural technologies required for terraced rice cultivation differ in this sense from those for rice cultivation in the plain. Terraced rice cultivation in the Ailao Mountains has been widely studied. However, most of these are folklore studies that place more emphasis on the description of the Hani people’s traditional culture. No empirical studies have yet been conducted to examine agricultural technologies from the agro-ecological characteristics of the terraced paddy field.

In the Ailao Mountains, various kinds of unique agricultural technologies can be observed. For example, most of the terraced paddy fields in this area are irrigated even during the fallow period when no crops are grown. This irrigation practice not only prevents farmers from growing the second crop, but also requires continuous water supply during the dry season. However, farmers adhere to this traditional irrigation practice even when they introduced improved rice varieties including the hybrid rice, which require occasional water drainage during the growing season to maximize productivity. This example closely relates to the specific technological requirement for terraced rice cultivation.

This study aims to illustrate how terraced rice cultivation has been developed and sustained over many years in the Ailao Mountains from the viewpoint of agricultural technologies, especially focusing on irrigation and drainage systems. It is also an attempt to understand the technological characteristics of the terraced rice cultivation in comparison with rice cultivation in the plain.

By Adachi Shimpei, ASAFAS, Kyoto University

(To be continued)

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