|2020 Vision Focus 4 - Promoting Sustainable Development in Less-Favored Areas (IFPRI, 2000, 18 p.)|
Sushil Pandey is an agricultural economist at the International Rice Research Institute (IRRI), Los Baños, Philippines.
Uplands in Southeast Asia account for about 50 million hectares with over 100 million people directly dependent on them. Rice is a major food crop in the uplands, and the food security of upland people depends on its production. Total rice area in the uplands of Southeast Asia is estimated to be 4 million hectares. Countries in this region include Cambodia, Laos, Myanmar, the Philippines, Thailand, and Viet Nam. Population density in these countries varies from 20 per square kilometer in Laos to 225 per square kilometer in the Philippines. Uplands are highly heterogeneous with the climate varying from humid to subhumid and the soils varying from fertile to highly infertile. Uplands also include flat to steeply sloping areas. Cultivation practice ranges from shifting to permanent cultivation. The crops grown in the uplands also vary across these environments. Despite this diversity, a general feature of the upland system is that it is inhabited by very poor farmers who grow food crops mainly for subsistence using very few inputs other than labor. Upland areas are often remote with poor access to markets. They are also generally inhabited by ethnic minorities who are often socially and politically disadvantaged.
In addition, upland areas suffer from a number of resource degradation problems such as deforestation and erosion. Property rights to land and forest resources are often poorly defined and enforced. In some cases, indigenous systems of land rights are being eroded because of public sector interventions, excessive immigration, and high rates of natural population growth. High population pressure, low agricultural productivity, and resource degradation in the uplands of Southeast Asia pose real challenges for designing development strategies that alleviate poverty in a sustainable manner.
Any strategy for achieving poverty alleviation in upland environments must stimulate growth in agricultural productivity, raise incomes, and conserve resources. Current agricultural productivity is low. For example, the yield for rice, an important food crop in the uplands of Asia, is only 1.1 metric tons per hectare compared with 4.9 metric tons per hectare for irrigated areas. The traditional system of slash-and-burn based on fallow periods in excess of 20 years has been replaced by short fallow - in some cases less than two years - owing to increased population pressure. Technological and institutional interventions to improve the yields of major staples are needed to increase overall food production. At the current low level of income (for example, US$78 per capita per year in the uplands of northern Viet Nam), enhancing food security and alleviating poverty will also require generating additional sources of income, particularly where environmental constraints limit opportunities to increase food production. Finally, various developmental activities in environmentally fragile upland areas must be resource conserving so that long-term growth can be sustained.
TYPOLOGIES OF UPLAND RICE SYSTEMS
A typology of upland rice systems of South and Southeast Asia can be created based on population density and the degree of market access (see figure). In this idealized typology, increasing population pressure pushes farming systems to become more intensive and sedentary. Increasing market access moves the systems toward more commercial production of nonrice crops. In areas with low population pressure and limited market access, the traditional system was shifting cultivation with long natural fallow, but these areas are declining because of increasing population pressure and political reactions against unsustainable slash-and-burn cropping. Integrated rice-based systems, where upland rice is grown in rotation with a range of annual crops in permanent fields, are found in situations with high population pressure but limited market access and are the dominant systems in Asia. In areas with greater access to markets, opportunities exist for development based on cash-cropping although food production may still be an important component of the farming systems. Type I, Type II, and Type IV systems predominate in Southeast Asia, while the Type III system is found mostly in South Asia. In both Type I and Type III systems, improving the productivity of upland rice can be an important starting point for addressing the problem of poverty. For other types of upland systems, plantation crops and other cash crops are likely to be the dominant components of farming systems even though rice will remain important for food security.
A Typology of Upland Rice Systems
The major biophysical constraints to the growth of rice yields in the uplands of Southeast Asia are drought, weeds, blast (a fungal disease), nematodes, and infertile soils, which are deficient in phosphorus and are generally acidic. In addition, soil erosion is an important problem, especially in sloping uplands. While improving rice germplasm will affect the rice crop only, improving soil fertility will help make other crops more productive as well.
Technology research for germplasm improvement at the International Rice Research Institute and collaborating partners in various countries is focused on developing varieties that escape, tolerate, and resist drought. Short-duration varieties that mature before the end of the rainy season escape the damaging late season drought that occurs in some areas. Varieties that tolerate and resist drought are needed for areas where intermittent drought can occur anytime during the growing season. Researchers are studying physiological mechanisms for drought resistance and using molecular tools to identify genes that impart such resistance. While this prebreeding work should ultimately reduce production losses to drought, most of the modem varieties currently being adopted in Asian uplands are shorter-duration varieties that escape drought. The adoption of these varieties has, however, remained somewhat limited because of other constraints including the unavailability of seeds.
Weeds and blast are two other major constraints to the production of upland rice. Manual weeding is extremely labor intensive, but most farmers cannot afford chemicals for weed control. As most of the losses to weeds occur during the early stages of crop growth, rice varieties with high seedling vigor that establish themselves rapidly are being developed to reduce the competitive effects of weeds. Similarly, allelopathic rice varieties that smother weeds through toxic chemical exudates are being evaluated. In addition to these germplasm-based weed control measures, various weed management strategies that combine tillage, crop rotation, and manual weeding are being evaluated.
For tackling soil fertility problems, the focus of research is on understanding long-term nutrient dynamics in upland soils, with particular emphasis on phosphorus. Researchers are also focusing on nutrient management in drought-prone soils, particularly the effects of nutrients on alleviating drought-induced yield reductions. Scientists are developing nutrient management strategies that rely on biological principles of nutrient cycling and assessing how such strategies can complement or substitute for external sources of nutrients. Research has shown that rice can yield three to five metric tons per hectare if adequate quantities of nutrients, particularly phosphorus, are provided in these poor soils. Similarly, technologies for controlling soil erosion are being developed and evaluated. A socioeconomic study of adoption of contour hedgerows for soil erosion control identified several factors, such as the security of tenure, farm size, and educational status of farmers, as critical determinants of adoption. Contour hedgerows were found to be effective in controlling soil erosion and increasing farmers' incomes in places that are more accessible to markets. The use of contour hedgerows for controlling soil erosion has, however, not been widespread as its profitability is somewhat location-specific.
An important technological intervention with high potential for impact in the uplands is agroforestry. A suitable combination of annual and perennial plants can help maintain soil fertility, because perennial crops help recycle nutrients and reduce soil erosion. In addition, perennial plants such as fruit trees can be an important source of cash income to poor upland farmers. The success of agroforestry-based intervention, however, depends on access to markets and the security of land tenure.
AN OVERALL STRATEGY FOR UPLAND DEVELOPMENT
While improved crop and resource management technologies are important for the development of Asian uplands, institutional and policy interventions also play critical roles. Upland areas must develop effective economic linkages with the national economy to enhance food security and income growth. Enabling policy and institutional environments are needed to encourage activities such as horticulture and agroforestry for which the uplands have a comparative advantage. Such policy interventions include development of infrastructure and marketing institutions and reform of property rights institutions. Much of the degradation of upland environments can be arrested or at least slowed through watershed-based development that recognizes the role of community participation in managing various resources within the watershed. Policies and technologies that encourage diversification to exploit the agroclimatic niches that exist in these heterogeneous and diverse environments hold much promise for sustainable poverty alleviation in Asian uplands.
For further information see C. Piggin et al., "The IRRI Upland Rice Research Program: Directions and Achievements," IRRI Discussion Paper Series No. 25 (Los Baños, Philippines: International Rice Research Institute, 1998).