Economic aspects of agroforestry

Agroforestry is analysed by means of economic concepts. The paper is mainly theoretical, since there are little adequate data to test the conceptual framework.Agroforestry needs not be limited to integration of agriculture and forestry on a plot, but may also include integration on a holding. Design and evaluation of agroforestry systems require thorough knowledge of relationships between agriculture and forestry. Complementary and supplementary relationships, mainly resulting from biological factors, were identified, which make agroforestry an efficient system of land use.Agroforestry can be an appropriate technology in areas with fragile ecosystems and subsistence farming. The objectives of participants in an agroforestry programme may not coincide with social objectives, and so do not lead to the socially optimum combination of agriculture and forestry. For that social optimum institutional arrangements will often be required.This paper is s shortened updated version of part of a lecture series on agroforestry, organized by the Departments of Forestry, Agricultural University, Wageningen [29].The author thanks his colleagues C.P. Veer and K.F. Wiersum for helpful comments.     

Agroforestry education and training programs: an overview

Agroforestry has been incorporated in education and training programs at an unprecedented level since 1982. A survey of educational institutions conducted by ICRAF in 1987 revealed that agroforestry is found as an option for specialization in undergraduate as well as in postgraduate M.Sc, diploma programs in forestry, agriculture, natural resources, and others. Courses and special seminars in agroforestry are organized in degree programs. Full undergraduate and postgraduate programs in agroforestry are being formulated and implementation started in quite a few universities, and many students are choosing agroforestry-oriented research projects for their dissertations. A good setting for higher degree training in agroforestry requires, however, staffing from combined faculties of at least agriculture, animal science and forestry; faculty commitment to a farming systems approach; and inter-departmental cooperation in teaching and research. It was difficult to asses whether these and other elements are present in existing programs where agroforestry has been incorporated. Emerging trends indicate that traditional forestry programs are broadening the scope of the discipline (from forests to integrated land-use systems) while agriculturists are recognizing that trees play important roles as soil improvers and protectors, fodder, food, fuel and other domestic and commercial purposes. New institutional structures are evolving to allow for educational programs with coursework and research projects spanning many disciplines. Nondegree training in agroforestry has seen an upsurge of activities equal, if not larger, to that in education. Attempts are being made by different institutions worldwide to inventory training opportunities; still the collection and dissemination of information is difficult. Efforts are needed at the international, regional, and national levels, to address training issues that if addressed collectively can improve the quality and effectiveness of human resource development efforts. ICRAF's approach to promote agroforestry research through education and training is an example of an action program currently under application.     

Program design for agroforestry extension in the south-eastern USA

Before prioritising regional agroforestry training and extension content, it is necessary to discover which practices are common, what benefits are perceived, which barriers prevent use, and how people feel about practices. Agroforestry taps both agriculture and forestry agencies to increase the possible set of educators for landowners and managers. Interdisciplinary activities also present barriers to professionals unfamiliar with some topics or not served by lead partner agencies. To understand motives, barriers and needs involved in agroforestry extension and training activities for professionals, the Center for Subtropical Agroforestry (CSTAF) designed a survey to gauge knowledge, practice and information needs of professionals in Alabama, Florida and Georgia. Landowners in Alabama and Florida received similar survey questionnaires. Initial interviews of a test group with open-ended questions formed the basis for a closed-ended mail survey to all agriculture and natural resource extension agents and county foresters in the subtropical area. Response rates for various professional groups varied between 14% and 43%, and most ranked the potential for use of agroforestry as moderate or high. In all three states, wildlife habitat, water quality and soil conservation were the most important benefits seen by extension professionals. The most important concerns identified were lack of familiarity, lack of demonstrations, no financial incentive, and lack of information about agroforestry. These data provide insights about how to prioritise research and materials development and indicate that agroforestry training can be expected to be of value to at least half of the regional forestry and extension professionals.     

Alternate cycle agroforestry

Agroforestry research and design has heavily favored intergrated production of annuals and perennials, that is production of tree crops on the same parcel of land and at the same time as production of food crop annuals. For areas having high population densities and intensive modes of agricultural production, integral agroforestry may be appropriate, but for areas of sparse population where extensive agriculture is practiced or marginal hill lands, alternate cycle agroforestry may prove more suitable. Alternate cycle agroforestry, in the form of modified forest swidden systems, is discussed and compared to integral agroforestry systems. Advantages and disadvantages of each system are discussed relative to their use on marginal hill and forest lands.The author wishes to thank N.T. Vergara, L.S. Hamilton, A.T. Rambo and K.F.Wiersum at the Environment and Policy Institute of the East-West Center for their comments.     

Prospects for easing land tenure conflicts with agroforestry in Mediterranean France: a research approach for intercropped timber orchards

Agroforesty plots offer the opportunity to combine annual agricultural production and long-term wood capitalization. The fallow scheme now in operation in Europe intends to reduce the surplus of agricultural products. Agroforestry management could be a valuable alternative to fallow or to forestry plantations on agricultural land.Agroforestry is attractive to agricultural landowners in Mediterranean France, as agroforestry stands are less costly than forestry plantations, are less prone to fire hazards, provide agricultural returns from intercropping during the first twenty years and have many environmental benefits.An experimental network of on-farm agroforestry plots has been set up since 1988 in the Mediterranean part of France. These plots include grazed paddocks (silvopastoral systems) and ungrazed fields (silvoarable systems). They gained support both from landowners and tenants: the former expect a high value treestock, while the latter have a free use of the space between plantation lines. Plantations have been designed to allow easy mechanical intercropping. First results from two experimental sites are discussed. The growth of the trees in the agroforestry plots is much higher than in the control forestry plots.     

Agroforestry landscapes and global change: landscape ecology tools for management and conservation

Forest ecosystems are impacted by multiple uses under the influence of global drivers, and where landscape ecology tools may substantially facilitate the management and conservation of the agroforestry ecosystems. The use of landscape ecology tools was described in the eight papers of the present special issue, including changes in forested landscapes due to agricultural and forestry activities, landscape changes due to recent intensification of agriculture, and the impacts of agroforestry as compared to natural forest ecosystems. Landscape ecology can improve the economic, environmental and social values of agroforestry, and this knowledge should help to develop new management alternatives for agroforestry. We believe that these papers will inform management at the landscape level, especially in agroforestry landscapes, offering new tools for management and conservation.     

Agroforestry for ecosystem services and environmental benefits: an overview

Agroforestry systems are believed to provide a number of ecosystem services; however, until recently evidence in the agroforestry literature supporting these perceived benefits has been lacking. This special issue brings together a series of papers from around the globe to address recent findings on the ecosystem services and environmental benefits provided by agroforestry. As prelude to the special issue, this paper examines four major ecosystem services and environmental benefits of agroforestry: (1) carbon sequestration, (2) biodiversity conservation, (3) soil enrichment and (4) air and water quality. Past and present evidence clearly indicates that agroforestry, as part of a multifunctional working landscape, can be a viable land-use option that, in addition to alleviating poverty, offers a number of ecosystem services and environmental benefits. This realization should help promote agroforestry and its role as an integral part of a multifunctional working landscape the world over.     

Factors constraining and enabling agroforestry adoption in Viet Nam: a multi-level policy analysis

Agroforestry is known to have multiple economic and environmental benefits. Despite this, the adoption of agroforestry in Viet Nam is limited both in extent and diversity of components and practices. Our study identified gaps for agroforestry adoption in current policies and policy implementation. National policy and provincial instructions and decisions were reviewed and discussed during ten stakeholders’ consultation workshops. The review and workshops concluded that there were no specific national and few provincial specific policies promoting agroforestry. In addition, the segregation of policies into agriculture and forestry, promoted monoculture practices and discouraged the integration of mixed annual and perennial tree species. Completing the forestland allocation process was considered essential for long-term investment on land and providing collateral for loans. More holistic policies, such as a provincial strategy for agroforestry development that would enable flexible integration of agriculture, forestry and livestock were perceived to be more effective and inclusive to poor and non-poor farmers. Specific cross-cutting budget allocation would be necessary for capacity building, upscaling agroforestry models, procurement of high-quality inputs, and establishing post-harvest processing and marketing investments.     

Agroforestry and its application in amelioration of saline soils in eastern China coastal region

Some environmental problems, especially soil salinity hinder the regional sustainable development of eastern China coastal region. Salinity mainly comes from tide weave, seawater flooding and seawater intrusion. Over exploitation of groundwater,which is the result of unfitful land use systems, leads to seawater intrusion and salt concentration increase. Agroforestry systems can enrich soil fertility and prevent soil salinization, furthermore help maintain biodiversity and enhance productivity. For the intergrated multiple ecosystems the most critical issue is to select optimum tree species and rationally arrange these plants. The basics of this multiple ecosystem is that different plants will occupy variable ecological niches within an area, both in space and in soil depth.Shelterbelts and trees intercropping with agricultural crops are major types of the multiple ecosystem. Shelterbelts can reduce wind speed and consequently lessen evaporation and erosion of the soil, increase pasture growth by up to 60% on exposed sites, increase crop yields by up to 25%. Besides intercropping with jujube, other agroforestry multiple ecosystem such as forestry plus agriculture,forestry plus agriculture plus fishery, and forestry plus animal husbandry are the most appropriate ways to utilise land resource in this region.     

Agroforestry in central,northern, and eastern Europe

Integrated management of natural resources and the multiple use of trees and forests have prevailed in most European societies since prehistoric times. In the Middle Ages, expanding and intensified agriculture resulted in the separation of trees from agricultural fields. During the last century, with the introduction of sustainable and highly productive forest management, the goal of increased wood production has been achieved in most parts of central, northern, and eastern Europe. Today, agroforestry is not considered to be an important land-use option within the region; however, there are many practices that could rightfully be classified as agroforestry. These include tree/crop systems in which trees provide products and/or environmental benefits, and tree/animal systems in which animals are grazed in forests or open woodlands.The future seems to offer some prospects for agroforestry. Large areas, hitherto used for food production, are either marginally suited to agriculture, or will probably be taken out of production due to agricultural policy considerations. Agroforestry may, at least in part, offer alternatives for the use of such lands. The availability of (surplus) fertile soils, capital, and labor may provide incentives for site-adapted forms of agroforestry, including improved fallow management. The focus of such systems would be on maintenance of biodiversity in the landscape, environmental protection, recreation, and product diversification.There are numerous expectations as to what agroforestry might provide for the land holder and for society as a whole. These expectations should be carefully analyzed and evaluated prior to political decisions on future land use. The promotion of agroforestry requires overall investment; agroforestry does not happen by itself. A set of integrated actions — not isolated efforts — must be implemented if agroforestry is to become a successful land-use option.     

Farming carbon: an economic analysis of agroforestry for carbon sequestration and dryland salinity reduction in Western Australia

The widespread removal of native trees from the agricultural zone and replacement with annual crops and pastures is a major cause of dryland salinity in Australia. It has been recognised that a large proportion of the landscape needs to be replanted to trees to prevent further salinisation. However, for much of the agricultural zone, agroforestry is not an option due to lack of species that can viably generate the products currently demanded by the market. The emerging carbon market may provide a new agroforestry option for landholders, through carbon sequestration. This analysis assesses the viability of growing trees for the purpose of selling carbon credits, from a landholder’s perspective. Benefits of trees in preventing the onset of dryland salinity are accounted for. Two regions in Western Australia; a low rainfall (330 mm/year) region and a medium rainfall (550 mm/year) region, are analysed. At the expected carbon price of A$15/tCO₂-e, growing trees for carbon is not a viable alternative for landholders in the low rainfall region, due to low sequestration rates. In the medium rainfall region, growing trees for carbon and timber is a viable alternative; however the opportunity costs of land mean the carbon price would still need to be higher than expected for growers to choose this alternative. Accounting for the salinity prevention benefits makes growing trees a more attractive investment for landholders in both regions. However in both regions, even after accounting for salinity benefits, the price of carbon would need to be A$25–A$46/tCO₂-e higher than expected to make growing trees a worthwhile investment.     

The farming system and traditional agroforestry systems in the Maya community of San Jose, Belize

Shifting slash-and-burn agriculture is likely one of the main causes of forest degradation in southern Belize. Although many development projects have attempted to reduce the impacts of agriculture on the tropical rainforest, the situation is still a cause for concern. A study of the farming system of the San Jose Maya community was therefore carried out to examine agricultural production in its social, cultural, economic, and political context. Results demonstrate that agricultural production contributes to forest degradation because of the limited availability of agricultural land, the low level of investment in agricultural production, the land tenure system, limited marketing opportunities, and the exclusion of Mayas from the country's political and economic domains. Agroforestry could, however, offer a partial solution to the problem of forest degradation. Three types of traditional agroforestry systems are practised in San Jose: the milpa (a slash-and-burn agriculture system), cacao (Theobroma cacao) cultivation under shade trees, and the homegarden. These traditional agroforestry systems almost entirely meet a family's needs for food and wood, and generate at least 62% of family income. Improving the productivity of these systems could help to reduce pressure on the forest in southern Belize.This revised version was published online in November 2005 with corrections to the Cover Date.     

苏北平原地区森林贡献与效率测算及分析

以苏北地区1991--2001年的数据，采用随机前沿生产函数的效率模型和超越对数生产函数对农田林网和小片林对农业总产值、种植业产值和畜牧业产值的贡献程度进行计量并分析，结果表明：农田林网对上述3个产值的生态贡献率为负值，小片林对上述3个产值的生态贡献率为正值，林业、种植业和畜牧业之间存在明显的联合生产效果。需要扩大小片林面积和对现有农田林网进行适当改造，以期取得更好的效果。     

The Bioeconomic Potential for Agroforestry in Australia’s Northern Grazing Systems

Although agriculture generates 16% of Australia’s greenhouse gas emissions, it also has the potential to sequester large quantities of emissions through land use management options such as agroforestry. Whilst there is an extensive amount of agroforestry literature, little has been written on the economic consequences of adopting silvopastoral systems in northern Australia. This paper reports the financial viability of adopting complementary agroforestry systems in the low rainfall region of northern Australia. The analysis incorporates the dynamic tradeoffs between tree and pasture growth, likely forest product yields, carbon sequestration and livestock methane emissions in a bioeconomic model. The results suggest there are financial benefits for landholders who integrate complementary agroforestry activities into existing grazing operations at even modest carbon prices.     

Agroforestry research in India: a brief review

India's long tradition of agroforestry has been influenced by numerous religious, social, and economic factors. Several indigenous agroforestry systems, based on peoples' needs and site-specific characteristics, have developed over the years. Agroforestry research was initiated in the country about two decades ago; since then, considerable progress has been achieved. The interactions between and among the tree, crop, grass, and animal components have been studied, and several agroforestry technologies have been developed and tried on farmers' lands. Agroforestry research is now conducted under the auspices of the All India Coordinated Agroforestry Research Project of the Indian Council of Agricultural Research at 31 centers distributed over India's tropical and temperate regions. In addition to research, the program includes agroforestry training of farmers, technicians, and scientists at 28 centers throughout the country. Expectations from agroforestry are high in India in both rural and urban areas; these expectations include production benefits that are in harmony with the ecology, environment, traditions, and heritage of the country.     

The effects of management and plant diversity on carbon storage in coffee agroforestry systems in Costa Rica

Agroforestry systems can mitigate greenhouse gas (GHG) emissions, conserve biodiversity and generate income. Whereas the provision of ecosystem services by agroforestry is well documented, the functional relationships between species composition, diversity and carbon (C)-storage remain uncertain. This study aimed to analyze the effects of management (conventional vs. organic), woody plant diversity and plant composition on aboveground and belowground C-storage in coffee agroforestry systems. It was expected that organic farms would store more C, and that an increase in plant diversity would enhance C-storage due to complementarity effects. Additionally, it was expected that steep slopes decrease C-storage as a result of topsoil erosion. Woody plants were identified on 1?ha plots within 14 coffee farms (7 conventional and 7 organic). C-stocks in trees, coffee plants and roots were estimated from allometric equations. C-stocks in litter and topsoil (0?C25?cm) were estimated by sampling. On average, farms stored 93?±?29?Mg?C?ha^?1. Soil organic carbon accounted for 69?% of total C. Total C-stocks were 43?% higher on organic farms than on conventional farms (P?<?0.05). Conventional and organic farms differed in vegetation structure, but not in species diversity. It was found that the combined effect of farm type, species richness, species composition and slope explained 83?% of the variation in total C-storage across all farms (P?<?0.001). Coffee agroforestry in general and organic farms in particular may contribute to GHG mitigation and biodiversity conservation in a synergistic manner which has implications for the effective allocation of resources for conservation and climate change mitigation strategies in the agricultural sector.     

中国亚热带东部地区的主要农用林业模式

在对我国亚热带东部地区的农用林业进行全面调查研究的基础上,按照国际农用林业研究委员会的农用林业分类系统,并参照有关文献,对该区现有的农用林业模式进行了分类和描述。结果表明,该区的农用林业模式种类丰富,模式的组成成分多种多样。其中有些模式规模较大,历史悠久。已经产生了巨大的社会、生态和经济效益。建议今后要加强对农用林业的研究,不断创立和优化适宜的农用林业模式。为实现农林牧副渔各业发展创造条件。     

Tree gardening and taungya on Java: examples of agroforestry techniques in the humid tropics

Agroforestry is a general concept for a land management system combining trees and agricultural crops. For application, various specific techniques can be chosen. Each of these techniques is adjusted to a specific set of environmental as well as socio-economic factors. Agroforestry cultivators or managers belonging to varying social strata and institutional groupings may practice different forms of agroforestry, even within the same general region. This is demonstrated on the basis of two contrasting types of agroforestry which are found on the Indonesian island of Java. Tree gardening or the cultivation of a wide variety of crops in a multiple-storeyed agroforestry system is an indegenous practice on private lands, while taungya or the intercropping of young tree plantations with staple crops is practiced on state forest lands. Both systems are described as to their management characteristics, past development as well as possibilities and constraints for further development. These two practices are then compared as to various attributes, like producer group, production purpose, area of cultivation, land ownership situation, structural organization of crop combinations, possibilities for improved cultivation techniques, and suitability for application in rural development for specific target groups.This paper is a slightly revised version of a contribution to a lecture series on agro-forestry organized by the Departments of Forestry, Wageningen University.     

森林、林业活动与温室气体的减排增汇

大气中CO_2等温室气体浓度上升引起的全球变暖,威胁着人类生存和社会经济的可持续发展。在减少温室气体排放、稳定大气CO_2浓度的措施中,森林和林业活动扮演着重要的角色。森林可吸收并固定大气CO_2,是大气CO_2的吸收汇和贮存库;而毁林是大气CO_2的重要排放源。通过适当的林业活动可增强碳吸收汇、保护现有的碳贮存,通过替代措施可减少化石燃料引起的温室气体排放。因此,林业活动在未来减缓大气温室气体上升方面将发挥重要作用。阐明了全球和中国森林生态系统在减缓大气CO_2浓度上升中的作用以及与土地利用变化和林业有关的减排增汇措施和潜力,以期对我国制定CO_2减排增汇政策提供参考依据。     

Agroforestry techniques in tropical countries: potential and limitations

Agroforestry designates land management techniques, which implies the combination of forest trees with crops, or with domestic animals, or both. Because of their interdisciplinary character, they are of particular interest for many countries of the Third World, where an equilibrated development of all rural lands must be obtained. It is no longer tolerable to consider separately forestry and agriculture in the tropics, and to manage forest resources as an isolated ecosystem. Through his traditions, the tropical farmer is an agro-forester and it is possible to take advantage of his experience in forestry, in order to increase the yields of his agricultural crops. A sustained yield agriculture is the best protection for tropical forests. A classification of the principal agroforestry techniques is proposed and some traditional practices are described. The outstanding advantages of agroforestry in the social, economic and ecological fields suggest some principles for future investigation programs, which will still have many problems to solve.

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Résumé Les techniques agroforestiéres désignet toutes les méthodes de production, où des arbres sont associés aux cultures agricoles, à l'élevage, voire même aux deux à la fois. Du fait de leur caractère interdisciplinaire, elles s'imposent dans de nombreux pays du Tiers-Monde pour atteindre un développement harmonieux du milieu rural. Il n'est en effect plus permis de considérer séparément forêts et agriculture dans les tropiques et de gérer le patrimoine forestier en vase clos. Le paysan du Tiers-Monde est un agroforestier par tradition et il s'agit de mettre en valeur ses connaissances forestières pouvant améliorer les rendements agricoles, et vice-versa. Une agriculture à rendement soutenu est la meilleure protection pour les forêts tropicales! L'article propose une classification des principales techniques agroforestiéres en décrivant quelques pratiques bien établies. L'énumération des avantages sociaux, économiques et écoolgiques de ces techniques suggère quelques principes pour les travaux de recherche qui doivent résoudre les nombreux problèmes posés.