AGROFORESTRY IN THE MANAGEMENT OF SLOPING LANDS IN ASIA AND THE PACIFIC

Steeply sloping lands are widespread in the tropics. An estimated 500 million people practice subsistence agriculture in these marginal area s. Continued population growth has led to the intensified cultivation of large areas of the sloping lands, exacerbating the problem of soil erosion. Although research shows that alley cropping and other contour agroforestry systems can stabilize the sloping lands, these systems h ave not been widely adopted by farmers. The Framework for Evaluating S ustainable Land Management (FESLM) has been tested in sloping land are as in the Philippines. Sustainable land management must be productive, stable, viable, and acceptable to farmers, while protecting soil and water resources. Farms on which contour hedgerow intercropping has bee n adopted meet the multifaceted requirements of FESLM, whereas the far mers' current practice does not. Appropriate land management measures for particular locations depend on a complex suite of social, economic , and biophysical factors, and need to tx:developed in participation w ith farmers. The role of agroforestry in sustainable management of slo ping lands is the subject of networks coordinated by the International Board for Soil Research and Management (IBSRAM) in seven countries in Asia (ASIALAND) and four countries in the Pacific (PACIFICLAND). We r eview selected outcomes from a wealth of network data. From these resu lts the following conclusions about the sustainability of various agro forestry systems for sloping lands can be drawn: In the Pacific, soil loss from sloping lands due to water erosion under farmers' current pr actices is episodic, unpredictable, and possibly not severe; Agrofores try systems that utilize legume shrubs, fruit trees, coffee (Coffea sp p.) or rubber (Hevea brasiliensis) provide useful economic returns, bu t are not an essential component in terms of soil protection because g rass or pineapple (Ananas comosus) planted on the contour are equally effective in reducing erosion; Agricultural intensification will lead to nutrient mining, reduction of aboveground biomass, declining yields , and less soil protection unless external sources of nutrients are us ed; nitrogen can be effectively supplied using legumes;Cash derived fr om hedgerow trees and/or shrubs may provide an incentive for their ado ption by farmers, as well as funds to purchase external inputs such as fertilizers; Labor may be a major constraint to the adoption of compl ex agroforestry systems. We also discuss the information management sy stems required to effectively manage and utilize the extensive sets of experimental and indigenous data being accumulated. We believe such i nformation systems can facilitate technology transfer across and betwe en regions, and improve the efficiency of research into agroforestry a nd other land-management approaches.