@article{oai:ir.kagoshima-u.ac.jp:00010976,
 author = {Nakano, Kazutaka and 中野, 和敬},
 issue = {2},
 journal = {南太平洋研究, South Pacific Study},
 month = {Mar},
 note = {This paper examines the human ecology of swidden cultivation, specifically the labour inputs required to
grow two staple crops: sweet potato (Ipomoea batatas (L.) LAMK.) in Malaita, Solomon Islands, where it is
cultivated under warm wet tropical conditions year round; and upland rice (Oryza sativa L.) farmed by the Karen
swiddeners over the intensive monsoon period in North Thailand. Field data including those based on time and
motion studies were collected through quantitative surveys during four periods on Malaita, between 1989 and 1995
and continuously from 1972 and 1974 in North Thailand. Working within a broad ecological framework.
information was collected from farmers on how much time they gave to cultivation of one hectare of land from
the point when it was cleared of relatively low growth fallow forest to harvesting of the crop. Malaita farmers did
not impress me as very strenuous workers and my data confirmed this. The Malaita gardeners invested 2.4 times
more time into a specific area of land during crop production. However, when labour input was measured against achieved calorific output, an apparently contradictory result was obtained. The calorific yield of sweet potato per
hectare far exceeded that of upland rice. According to a model calculation, the ratio of labour input required to
meet the respective necessary minimal calorific needs for one adult between Malaita and North Thailand is nearly
1:2. In other words, when measured based on calorific value of the principal staple crop, upland rice farmers have
to invest twice as much time as potato farmers in securing their staple food requirements. Furthermore, another
unignorable factor is that the climatically `always warm and rainy' conditions of Malaita make it possible for the
labour input to be evenly distributed throughout the year, thus allowing farmers to avoid crowding of their input
into one particularly busy season.},
 pages = {71--103},
 title = {A Markedly Important Aspect of the Human Ecology of Swidden Cultivation : the Labour Requirements for Producing Staple Crops in Solomon Islands and North Thailand},
 volume = {32},
 year = {2012},
 yomi = {ナカノ, カズタカ}
}