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Agricultural intensification and the role of forestry in northern Thailand

E.C. Chapman


Many of us at this workshop have seen major changes occurring over the past 10 to 20 years in the strength and variety of linkages between the valleys and the hill country of Northern Thailand. In the 1950s and early 1960s the economies and physical habitat of the lowland Thai were commonly seen as entirely distinct from those of the hill communities, with the two physically separated by a virtual no man's land in the zone of lower slopes between about 300 m and 800 m. Below were the towns and Thai villages focused on wet-rice cultivation. and up-slope were the scattered concentrations of hill villages, dependent upon swidden crops of rice, chillies, maize. opium, and other crops.

Certainly in the eyes of most observers in the early 1960s. including many academics and administrators. the differences between the hills and lowlands were overwhelmingly evident Only minor trading links existed between the two zones and the affinities between their economies were few indeed. But by the mid 1960s the distinction was becoming blurred: Thai swiddeners in Amphoe Thung Chang, Nan Province, for example. were growing crops at 600 to 800 m elevation. in close proximity to Htin and Hmong communities; and in the margins of the Ping valley Thai villagers were working as wage labourers in miang (tea) plantations. Population pressure in the Thai lowlands was clearly producing some movement to the inbetween areas of the lower slopes.

In the late 1970s it is a great deal easier to see an overall unity in the land-use systems of Northern Thailand, with the spectacular differences related, in the first instance, to the stage reached in the process of agricultural intensification, which in turn reflects differences in population pressure. resources, market access, and diffusion of knowledge. At the ''advanced'' end of the range, even excluding small areas of highly profitable crops, such as lamyai orchards, there are now many lowland villages where irrigated, triple cropping is practiced (e.g., rice tobacco/peanuts/soya beans-rice), particularly in Amphoe San Patong and Amphoe Chomtong, commonly with a total gross margin in the three-crop year exceeding B 4.000/rai.' At the other end of the range are the poorest swidden situations where fields are cropped every second or third year (mainly by lowland Thais, on river terraces or lower slopes) for a gross margin of about B 100/rai, including fallow land.

The contrast between these two farming systems is immense. Yet the areas I have in mind, between Amphoe San Patong and Amphoe Chomtong, were only just moving out of a rice monoculture (rainy season glutinous rice) in early 1966. Further north, in the same province (Amphoe Fang, Chiang Mai Province) some pioneer villages were only then converting swiddens on the low terraces of the valley floor into bunded fields for wet-rice cultivation. These observations help to emphasize how recent and rapid the process of agricultural intensification has been over the past 10 to 15 years in resource-favoured areas, in the immediate aftermath of malaria eradication and in response to population pressure. Over the period 1947 - 70 the region's population (seven provinces) grew by 88 per cent, to 3.9 million (Statistical Yearbook Thailand 1972-73; p. 44).

It is not necessary to brief this audience on the many microscale studies which have added so greatly in the past 10 years to our knowledge of swidden agriculture in Northern Thailand (Kunstadter, Chapman, and Sabhasri 1978, Geddes 1976; Hinton 1978: Walker 1970). Many studies have provided supporting evidence for the applicability of the Boserup historic-demographic model of agricultural change. reporting population growth. low agricultural productivity and. in some instances, the first critical steps being taken towards intensification from swidden systems into permanent-field farming. with the construction of agricultural terraces (Hinton 1973, p. 244). High labour costs are always a deterrent. In one recent study where labour costs for the construction of shallow agricultural terraces were quantified, for hill villagers using hoes, the labour involved amounted to 50 man-days/rat (Manajuti and Andrews 1977, p. 5). This investment looks high to a villager uncertain over land ownership and often more uncertain about his returns on the labour employed. In much of the tropical world it has been argued, ''because of the lower labour demands of shifting cultivation, economically rational farmers will not change to permanent-field cultivation without a stimulating force, often the combination of population pressure and degradation of forest fallow'' (Clarke 1975, p.107)

The transition from swidden to permanent-field cultivation is certainly the first essential step in agricultural intensification, but in the Northern Thai lowlands, at least, a second step was taken in the 1950s with the expansion of multiple cropping under dry season irrigation, again apparently in close response to mounting population pressure. Dry season cultivation has expanded symbiotically with the progressive commercialization of lowland farming, and with a rapid expansion of market contacts between villagers, merchants, and towns It has also stimulated a closer appraisal of natural resources, particularly water supplies, and through its generation of cash income, has played a powerful role in increasing the movement of lowland villagers, both within the Northern Region and beyond. Hill communities, of course, have been only marginally affected by these developments so far. but the spatial and social inequalities which now exist in lowland farming villages. as the product of differential development, are likely to lead to increased competition for land between hill peoples and lowlanders.

Resources and Agricultural Intensification

Dr. Samuel Johnson once said, ''When a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.'' Somewhat similarly, the existence of heavy population pressure in Northern Thailand by the early 1960s focused attention on resource opportunities in the northern valleys for second-crop irrigation. When the Agricultural Census was taken in 1963. 58 out of 64 amphoe (districts) in the seven northern provinces had population densities exceeding 500 per kmē and many tambon (communes) in Phrae, Nan, southern Lampang, Lamphun. and southern Chiang Mai provinces had densities exceeding 1,000 per kmē In a survey of 66 lowland villages in the seven northern provinces in 1966. about half the sampled households (47 per cent, in a total of 1,445 households) reported having grown a second crop after rainy season rice. with 67 per cent having grown a second crop for the first time within the per/oaf 1960 65 (Chapman 1967).

The sudden surge in second cropping was undoubtedly encouraged by population pressure, but it was helped also by the expansion of Government irrigation schemes under the Royal Irrigation Department. by the existence of ''people's irrigation projects.'' and by the previous introduction of Virginia tobacco (1930s), peanuts. soya beans, and mung beans. A fortunate accumulation of irrigation capacity in the Pinq valley near Chianq Mai for the production of profitable dry-season crops was available by the time the need for increased agricultural productivity occurred. Unhappily, need often occurs before the means of meeting it are available, as in the problems of opium replacement in the higher hill country above 1,000 m.

In the 1960s and 1970s not all lowland villages experienced either the need or the opportunity for agricultural intensification. In Chiang Rai Province the existence of larger holdings and markedly higher rice production per capita in the early 1960s reflected lower population pressure (Chapman 1967) and so less need for agricultural intensification. On the other hand, in the lowlands of Nan, and many similar areas of the northern provinces where population pressure was high. the inadequacy of dry season flow in the rivers. or terrain factors, often inhibited development.

Undoubtedly the most advantaged area for agricultural intensification in the 1960s and 1970s has been the central Ping valley south of the city of Chiang Mail Along its western margin. in particular, the middle and low terrace terrain is threaded by streams which have their headwaters in the hill country and supplied several important ''people's irrigation projects'' long before the Taeng River canal was completed and irrigation further developed in the 1970s By contrast, the eastern side of the Ping valley northeast from the town of Lamphun is parched during the dry season: in Nan. the middle terrace sequence occupies about three-fifths of the valley floor at elevations about 30 to 40 m above the low terrace. and beyond the easy reach of irrigation from the river. Even closer to the Nan River, the existence of a narrow, incised flood plain means that gravity flow irrigation is not easily practicable, as it is on the Ping, and so pump irrigation (at higher cost and with a greater maintenance problem) is required. Thus, opportunities for agricultural intensification have been very unequally distributed and remain heavily concentrated in the Ping, Wang, and Yom valleys.

The lack of irrigation opportunities in many areas has stimulated interest over the past 10 to 15 years in alternative ways for increasing agricultural production from neglected resources in the ''have-not'' areas. An early and most obvious response in the mid-1960s. in lowland villages scattered through central areas of the Yom, Ping, and Wang valleys was the attempted development of field-well irrigation, drawing water from shallow-depth aquifers, commonly at depths of 3 to 4 m. Its success was very limited. partly because of inadequate flow in many localities and partly because of the labour inputs or cash costs involved. More recently-and much more successfully- farmers in Amphoe Pa Sang. Lamphun Province, have established a mung beans-rice cropping system. planting mung beans in late April on the early rains for harvest in dune, followed by rice for harvest in December. To these two instances might be added many other agricultural endeavours, such as the expansion of orcharding. pineapple, and sugarcane production, again without irrigation, in further attempts to add to agricultural income. Commercialization of farming has proceeded rapidly over the past two decades in the lowlands. Just how far the transformation of a subsistence-oriented economy has changed, and is changing, was illustrated last year when farmers in a village near Chiang Mai replaced their traditional rainy season crop of glutinous rice (grown for domestic rice supplies) with non-glutinous rice for sale, in response to a 25 per cent price differential at harvest.

These efforts at agricultural intensification have depended mainly on villagers' initiatives, in response to resource and market opportunities. In at least three broad instances, however, official agencies have made significant contributions, beyond the scope of village endeavours. First, the Thai-Australian Land Development Project in Nan, Phrae, and Lampang has tackled the problems of establishing permanentficid cultivation on sandy podsolic soils: although limited to gentle slopes (preferably less than 3 to 4 degrees), in order to reduce the costs of erosion control, it has successfully established permanent-field cultivation of upland rice, mung beans. and soya beans on the more favourable soil series. Secondly, the Multiple Cropping Project of Chiang Mai University in association with the Ford Foundation, has tested alternative three-crop systems suitable for the irrigated lowland environment. Thirdly, and so far the most significant of the three, the important contributions made by the Ministry of Agriculture in the introduction of faster-maturing. higher-yielding rice varieties (particularly RD 1 and Rd 7) have greatly assisted the establishment of threecrop farming systems, at least in the limited areas of the Ping valley where water supplies allow.

The remarkable timeliness of these developments, providing opportunities for increased production when they were suddenly needed in response to population growth, should not allow us to forget the lead-up time and effort involved, for example in the 10 to 15 years before RD 1 was introduced or irrigation water flowed through the Taeng River canal. Furthermore, bearing in mind the concern of this workshop with efficient use of resources and with highland-lowland relationships in resource use, we may ask what major problems have emerged so far in the process of agricultural intensification in the lowlands.

One outstanding problem evident in the late 1970s is the inadequacy of existing water storages to meet the demands of the Chiang Mai lowland, despite the construction of the Kut Dam on the Taeng River (completed in 1969), Kiu Lom Dam on the Wang River (completed in 1973), and the various diversion weirs on the Ping, Wang, Yom, and Lao rivers. The addition of the Taeng River project and other new state irrigation projects increased the area irrigated by more than 60 per cent between 1960 and 1974, to approximately 100,000 ha: but with a heavy toll on river flow. Taking the Taeng alone, the diversion of water for dry season cropping in the five months from January to May increased from 20 per cent to 80 per cent of stream flow between 1960 and 1974-76. One consequence is that for three to four months each year (January-April) there is now almost no discharge from the Taeng into the Ping. Secondly, it is apparent that further increase of water usage in the Taeng River project (e.g.. for three-crop farming systems involving two crops of rice) will depend upon increased storage. or changes to crops with lower water requirements in the dry season. There is certainly no shortage of water if annual stream flows can be better utilized. In the Taeng River alone 75 to 80 per cent of the total discharge normally passes downstream virtually unused in the six months from June to November. No doubt the acceleration of wet season run-off from hill swiddens has reduced stream flow during the dry season, but a more conspicuous problem is the rapid siltation of dams and weirs from accelerated soil erosion in the hills. Dr. Sanga Sabhasri has shown that under a once-in-ten-years swidden cycle of the Lua' on steep slopes ranging from 29 to 44 per cent the losses due to erosion are chiefly incurred in the one year when the soil surface is exposed (and no doubt mainly during the first four to six weeks after rains begin). Revegetation by grasses, shrubs, and sprouting stumps quickly reduces the rate of soil loss (Sabhasri 1978, p. 170).

A second problem, now becoming starkly evident. is that agricultural development has been inadequate to meet the needs of many villagers, and that in fact many northern villages are becoming dormitories for a landless or near-landless proletariat. As an illustration, changes in Ban Pa Nang, Amphoe San Patong, between 1966 and 1977 help to indicate the magnitude of the problem. This village of 340 households (pop. 1,253, May 1977) lies at the foot of the hills along the western margin of the Ping valley. Its area of lowland fields (800 rai) did not change between 1966 and 1977, but the number of households grew from 178 to 340, including a net in-migration of 25 households. Setting aside six households of school teachers, the village policeman, and a midwife, only 146 out of 334 households (44 per cent) were "full owners": about 50 households were tenants (mainly in the dry season); and 120 households (36 per cent) lived from day to day as wage labourers. In this village all the lowland fields are now triple-cropped and agricultural intensification has brought major income benefits to about half the present households, while widening the gap between the rich and the poor within the village. Furthermore, the growth of landlessness in the pioneer farming areas of central Thailand, as a product of tractor cultivation, means that potential rural migrants are increasingly captive in their home villages, such as Ban Pa Nang (Chapman 1978).

Forestry, Agro-Forestry and Highland Development

In the lowlands forestry has played a minor, recessive role in the past 20 years. The cut over dry dipterocarp forest on river terraces and drier parts of the lower slopes, and the mixed deciduous forests on wetter sites and up to 600 m in elevation, have yielded ground to swidden and permanent field cultivation. Some of this land has been ceded to farmers under the legal provisions for amphoe land allocation, some has been released for farming by the National Land Classification Committee, but much has nominally remained in Forest Reserves long after being cleared illegally.

The passive role of the Royal Forestry Department towards so called squatters has had unfortunate consequences elsewhere-for example, in the eastern margin of the central plain, where tractor cultivation has allowed pioneer settlers to retain unusually large holdings, often 100 to 500 rai (16 to 80 ha) in area. In Northern Thailand, on the other hand, it is the Forestry Department's policy for teak reforestation in the mixed deciduous forest zone which is most open to question. Teak replanting- whether by the Royal Forestry Department itself, or by the Forest Industries Organization (FIO) in its ''Forest Village'' approach-employs the taungya system (originally used in nineteenth-century British Burma) to provide village labour for clearing. planting, and weeding Replanting began in 1942 (BE 2485) and in recent years has proceeded at a faster rate. exceeding 10,000 ha annually, mostly under the Forest Village scheme. The FIO deserves due credit for its paternalistic concern for the village labour it employs. Nonetheless, it seems clear that, compared with the swidden system it is displacing in some areas. reforestation with teak cannot support relatively high population densities. Kunstadter ( 1978.p 277) recently concluded from a comparison of FIO reforestation with the swidden systems of Lua' and Karen that the existing swidden economies support six to seven times the population sustained for a given area by the subsistence crops, cash crops. and cash income economies in a Forest Village scheme. In some cases teak reforestation amounts to appropriation (''expropriation''?) of land which Lua', Karen, and Thai villagers already use for farming and lumber purposes. This is the same land, moreover, which will be needed and exploited in greater measure for swiddens and permanent field farming (perhaps involving terracing?) in the future, if it does not remain locked in a teak plantation system for the next 60 to 80 years.

It may be important to recognize that swidden cultivation and taungya reforestation are on opposite sides of the interface between farming and forestry in tropical forest areas. Swiddeners recognize the importance of trees for nutrient replacement in the bush-fallow rotation; taungya reforestation mobilizes village labour for low-cost replanting, paying workers in kind (the opportunity for two or three swidden crops), as well as cash. Superficially taungya appears attractive in areas of low population density, but on closer examination its attractions are reduced by the losses of young trees due to burning, by the reluctance of farmers to stay for a second or third year as yields decline, and by the exclusion of villagers from decision-making or sharing in the eventual profits (60 years away!).

Taungya reforestation. as it is now practiced in Thailand, is clearly out of step with recent recommendations by FAO, IUCN, and other organizations concerned with the welfare of dwellers on the forest margins. At its Bandung meeting in 1974 IUCN issued guidelines for ''Land Use Policy and Allocation of Land to Various Uses'' which recommended inter alla that ''planning of the resource use should involve as far as possible consultation at local. regional and national levels with those people who are likely to be affected by the forestry operations

Agro-forestry, combining agricultural and forestry systems for the optimum benefit of farmers, is almost unknown in Northern Thailand. Heavy population pressure in the lowlands and in many stabilized swidden systems of the hill country largely rules out the possibility of including tree farming. In swidden systems where the cropping: fallow ratio has been reduced to 1:15 or below (and many occur around 1 :10) the scope for tree farming is probably limited to ridge tops, along rivers. and in small areas where individual communities wish to retain forests for village lumber and other purposes Even in these instance there are important constraints which would prevent agro-forestry systems being promoted on a large scale. Land tenure is not secure, there is insufficient knowledge about alternative market possibilities (e.g., for bamboo, fruit, fuel, or lumber) and there is meagre information about species most suitable for the range of ecological conditions found in the lower slopes and highlands of Northern Thailand.

In the wide range of attempts made over the past 10 years to establish profitable cash crops in the highlands, agro-forestry has attracted little attention. Understandably, most emphasis has been given to alternative high-value crops which might replace opium at elevations around and above 1,000 m (such as coffee and potatoes) and to efforts to use the extensive anthropogenic grasslands dominated by Imperata cylindrica for cattle grazing (Thai-Australian Highland Agriculture Project Third Report 1978). However, the possibilities for reforestation in the grasslands (e.g.. using Pinus kesiya) deserve more attention. No doubt major problems of soil nutrient deficiencies, access. and management would be encountered but the benefits of any research on the Imperata grassland wiIl extend throughout Southeast Asia.


Looking at the intensification of agriculture in the northern lowlands over the last 20 years, its dependence upon water for irrigation, and the marked differences which have emerged even within a single village between the ''haves'' and "have-nots,'' a few observations and suggestions seem appropriate.

  1. The magnitude of the landless problem in lowland villages needs close examination. It is likely to increase with further population growth and further competition for urban jobs as more hill people turn to the lowland towns for employment.
  2. In future development of the hill country. it seems inevitable that agricultural terracing will be more extensively developed wherever critical population pressure is felt and water resources allow. A survey of such possibilities, expanding from one watershed into many, would be a useful guide to development.
  3. As terracing expands, the experience of lowland villages is likely to be replicated: ''development'' will be selective and many villagers will be left as ''have-nots," with a greater need for assistance to obtain supplementary income outside agriculture.
  4. Implicit in the second and third observations above is the need to know more about the land cover (including the changing extent of Imperata grassland) in Northern Thailand, and the capability for terrace agriculture.


Chapman, E.C. 1967. ''An Appraisal of Recent Agricultural Changes in the Northern Valleys of Thailand.'' Bangkok: Department of Land Development. Mimeographed.

_________1978. ''Agricultural Development in Thailand in Retrospect and Prospect.'' Paper prepared for the Sydney Conference of the Asian Studies Association of Australia. Mimeographed.

Clarke, W.C. 1976. "The Maintenance of Agriculture and Human Habitats within the Tropical Forest Ecosystem." In Ecological Effects of Increasing Human Activities on Tropical and Sub- Tropical Forest Ecosystems. pp. 103 114. Canberra: Australian Government Publishing Service.

Geddes. W.R. 1976. Migrants of the Mountains. Oxford: Oxford University Press.

Hinton, P. 1973. "Population Dynamics and Dispersal Trends among the Karen of Northern Thailand.'' In R. Ho and E.C. Chapman, eds., Studies of Contemporary Thailand. Canberra: Research School of Pacific Studies, Department of Human Geography.

_________1978. ''Declining Production among Sedentary Swidden Cultivators: The Case of the Pwo Karen'' In P. Kunstadter, E.C. Chapman, and S. Sabhasri, eds., Farmers in the Forest. pp.185-198. Honolulu: University Press of Hawaii.

Kunstadter. P. 1978. ''Alternatives for the Development of Upland Areas.'' In P. Kunstadter, E.C. Chapman, and S. Sabasri. eds.. Farmers in the Forest. pp. 289 - 308. Honolulu: University Press of Hawaii.

Manajuti. D., and A.C. Andrews. 1978. ''Crops and Soil Conservation Research in 1976 77.'' Thai-Australian Highland Agronomy Project Third Report. pp. 5-9 Canberra: Australian Development Assistance Bureau.

Sabhasri. S. 1978. "Effects of Forest Fallow Cultivation on Forest Production and Soil.'' In P. Kunstadter, E.C. Chapman. and S. Sabhasri. eds., Farmers in the Forest. pp. 160-184 Honolulu: University Press of Hawaii

Thai-Australian Highland Agricultural Project. Third Report. 1978. Canberra: Australian Development Assistance Bureau.

Thailand. 1963. ''Census of Agriculture.'' Bangkok: National Statistical Office.

Walker, A R 1970. ''Labu Nyi (Red Lahu) Village Society and Economy in North Thailand'' Chiang Mai: Tribal Research Centre. Mimeographed.


The author is indebted to many former colleagues in the Land Policy Division and in the Thai-Australian Land Development Project of the Department of Land Development for help towards an understanding of agricultural changes in the northern lowlands Grateful acknowledgement is also made to the National Research Council of Thailand for permission to re visit a number of northern villages in 1977.

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