In areas affected by landslides in Japan, terraced paddy fields (known as tanada) are a characteristic feature. It has been clearly demonstrated, from a geological perspective, that environmental conditions determine the need for such terracing. However, little attention has been paid to social and cultural factors which lie behind the actual creation of terraced paddy fields. This paper attempts to clarify the process for development of tanada from a socio-cultural perspective, with particular reference to farm management strategy. The area selected for study is one of deep snowfall in the winter months. Matsuguchi village lies in the Higashi-kubiki mountain range, a tertiary formation prone to landslides, in Niigata Prefecture.
This study utilizes Land Registers for Matsuguchi village which date back to the 1880s. Between 1887 and 1951, over ten hectares of newly developed paddy fields were created in Matsuguchi. Invariably they are named tensui-den, a form of terraced paddy field. Although the term actually means ‘rain-fed paddy’, in Higashi-kubiki socalled tensui-den are not always totally dependent on rainfall. Some of these paddys have irrigation facilities including small reservoirs and yoko-ido (wells at the sides of the fields). Parcels of paddy field were also enclosed by high dykes, to hold water when necessary as if they were reservoirs. Such events invariably coincided with times of heavy snowfall. These simple facilities could be contructed by a relatively small labour force, so that large and small land-holders alike were able to incorporate them in tensui-den developments. Compared to more sophisticated irrigation structures (canals) elsewhere, however, tensui-den required more labour for paddy maintenance and rice growing. Productivity in tensui-den was also lower than in other types of paddy.
Creation and maintenance of tensui-den was only necessary, or feasible, in a situation where all the most productive (canal irrigated) paddy fields were owned by a single household, or when the market price of rice was high. In 1887 a single (absentee) land-holder owned 60% of all paddy fields in Matsuguchi village. His subsequent demise, and the fact that hired labour rates rose faster than rice prices, coincides with a slowing down of paddy field development after the 1920s. After the 1930s there was even a trend for abandonment of paddy fields. It seems, though, that other households actually increased their holdings of canal-irrigated paddy whilst giving up the less productive tensui-den paddys because continued maitenance of them was simply not worthwhile. Thus it is demonstrated that socio-cultural factors play a crucial role, just as environmental factors do, in the development of terraced paddy fields.
