Farm implements should be the cultural heritages of the societies which have particular production system on ecological base. In accordance with WELTH [1968], types of the plough in Mainland Southeast Asia show the both characteristics of Chinese mouldboard plough and Malayan beam plough (body ard) originated in India.
SHINTANI et al. have presented the notion of Tai Cultural Area for multi-ethnic societies in northern part of Mainland Southeast Asia, especially crossing of Ynnan Province of Southern China, northern part of Lao P. D. R. (hereinafter referred to as Laos), Northern Thailand and Shan State of Burma (Myammar) which has an organic linkage system on the linguistic, historical and cultural background.
Although detailed studies on Asian ploughs by HOPFEN [1960; 1969], CHANSELLOR [1961], IENAGA [1980], OJI [1980] and so, the information on this matter in Laos has been deficient for long time. This study focused the material culture on farm implements based on socio-ecological conditions in Northern Laos and aimed at elucidating the image of Tai Cultural Area by the interaction of the Tai with their neighbour through their own farm practices.
There is the general conception that Tai group has been paddy farmer. But rice culture in Northern Laos has been sustained by upland rice mainly. Anyhow, paddy farming has been conducted by Tai people in the valley plain along rivers and the montane basin. They have rice varieties that grown under both upland and lowland conditions and their paddy farming techniques have something common with slash-and-burn agriculture by non-Tai farmers which should be different from Central and Southern Laos.
The plough in Laos has mouldboard and is using with single buffalo jointed by single-neck yoke with rope traces and swingletree on lowland field task. The shapes may be classified into 1) vertical tension group behind mouldboard (frame plough), 2) cross joint group with no external reinforcement (X type) and 3) single joint group with no external reinforcement (Y type). Vertical tension group may be divided into quadrangular and triangular types. Triangular ploughs have three differentiations depending on straight or curved beam and with or without long body. Distribution of vertical tension group and Y type can be demarcated into Luang Phabang and northward and Vientiane and southward.
Some terms of plough parts e.g. shares / mouldboard in Central and Southern Laos show vocabularies to be having cultural back ground of Pali-Sanskrit Language. This trend should be overlapped with non vertical tension group and suggesting that the frame plough and non vertical tension group have different origin.
2 types of harrow can be observed in Laos. While spike harrow with quadrilateral framework is using by Lue and some other ethnic groups in northern part, comb harrow is universal throughout Laos.
These facts show that the south limit of spike harrow and the north limit of non vertical tension group plough may be in and around Luang Phabang. It will be necessary, in future, to investigate the plough used by non-Tai people in Northern Laos, and comparative study in Central and Southern.