Agroforestry in the management of sloping lands in Asia and the Pacific

Abstract

Abstract. Steeply sloping lands are widespread in the tropics. An estimated 500 million people practice subsistence agriculture in these marginal areas. 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 have not been widely adopted by farmers.The Framework for Evaluating Sustainable Land Management (FESLM) has been tested in sloping land areas 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 been adopted meet the multifaceted requirements of FESLM, whereas the farmers' 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 be developed in participation with farmers.The role of agroforestry in sustainable management of sloping 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 review selected outcomes from a wealth of network data. From these results the following conclusions about the sustainability of various agroforestry systems for sloping lands can be drawn:In the Pacific, soil loss from sloping lands due to water erosion under farmers' current practices is episodic, unpredictable, and possibly not severe; Agroforestry systems that utilize legume shrubs, fruit trees, coffee (Cojfea spp.) or rubber (Hevea brasiliensis) provide useful economic returns, but are not an essential component in terms of soil protection because grass 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 used; nitrogen can be effectively supplied using legumes; Cash derived from hedgerow trees and/or shrubs may provide an incentive for their adoption by farmers, as well as funds to purchase external inputs such as fertilizers; Labor may be a major constraint to the adoption of complex agroforestry systems.We also discuss the information management systems required to effectively manage and utilize the extensive sets of experimental and indigenous data being accumulated. We believe such information systems can facilitate technology transfer across and between regions, and improve the efficiency of research into agroforestry and other land-management approaches. 122

Applying Data Envelopment Analysis and Grey Model for the Productivity Evaluation of Vietnamese Agroforestry Industry

“…The MAPE values obtained are shown in Table 6. 2 5.663% DMU 7 2.069% DMU 3 2.256% DMU 8 1.124% DMU 4 4.001% DMU 9 14.513% DMU 5 5.021% DMU 10 7.046%…”

“…DMU5 always keeps a lower "technological changes" score, indicating that it has not actively improved its technology. Thus, DMU5 requires further investigation into the causes that lead to its tardiness on technology 5 , other DMUs had experienced an upward technological change, though most of them had experienced an efficiency drop during 2013-2014. This implies most of these DMUs had continued to improve their technological capabilities.…”

“…DMU 8 appears unstable due to having the largest fluctuation; thus, it requires intense care for its development. In summary, to sustain the development of the agroforestry industry, the Vietnamese government needs to especially focus on DMU 5 , DMU 1 , DMU 7 , and DMU 8 . …”

Biophysical interactions in tropical agroforestry systems

“…Soil conservation effects of hedgerow systems are discussed further in this volume by Craswell (1997). The various mechanisms of tree-soil-crop interactions in HI with respect to soil fertility, competition and weed control are reviewed in the subsequent sections.…”

Finding alternatives to swidden agriculture: does agroforestry improve livelihood options and reduce pressure on existing forest?

“…However, this is not the case in large areas of the tropics (Meijer et al 2015;Jepma 2013;Dahlquist et al 2007;Kiptot et al 2007;Craswell et al 1998). The research reported in this paper addresses this issue by analyzing the value of existing agroforestry systems, investigating their economic and social potential relative to swidden farming.…”