A bordered matrix approach to the bioeconomic modeling of agroforestry systems

A bordered matrix approach was developed as a technique designed to model multi-canopied agricultural or forestry production systems to find the optimal planting pattern and density meeting specified economic criteria. The approach uses monocultural production functions as a base from which to estimate polycultural production levels. A banana-cassava mixture is modeled to demonstrate how the technique can be applied.     

Amazonian agroforestry: a market-oriented system in Peru

Most reports on indigenous agroforestry systems of the Amazon region have described patterns employed by tribal groups almost exclusively for their own subsistence. This article discusses a market-oriented cyclic agroforestry system practiced by non-tribal Mestizo farmers in Tamshiyacu, Peru. The system produces charcoal, as well as annual, semi-perennial, and perennial crops for local consumption, and for a regional market. The sale of these products provides a substantial cash income for many farmers. The data presented demonstrate that Amazonian cyclic agroforestry systems are capable of being commercially successful enterprises and of serving as possible models for further agricultural development.

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Resumen La mayoria de informes sobre sistemas agroforestales indígenas de la regíon amazónica han descrito formas utilizadas por grupos nativos casi exclusivamente para su subsistencia. Este artículo trata de un sistema agroforestal cíclico comercial empleado por agricultores mestizos en Tamshiyacu, Perú. Este sistema produce carbón, huertos anuales, semi-perennes y perennes para el consumo local y para el mercado regional. La venta de estos productos da un ingreso considerable a muchos agricultores. Los datos presentados demuestran que sistemas agroforestales amazónicos pueden tener valor comercial y servir de modelos eventuales para el desarrollo agrícola.

     

Streuobst: a traditional agroforestry system as a model for agroforestry development in temperate Europe

The development of agroforestry for industrialised countries can be furthered by an understanding of the history and present functioning of traditional systems. In temperate Europe, fruit trees were traditionally grown on agricultural land undersown with crops or managed grassland (Streuobst). The historical evolution of this agroforestry system has been driven by the interaction of technical progress, market development and intervention by public authorities. Streuobst reached its peak in the 1930s, but has since been in continuous decline due to the development of intensively managed dwarf-tree orchards. However, even today, it still occupies approximately one million hectares in 11European countries and has a strong impact on the European fruit market. The profitability of streuobst is relatively poor due to its low labour productivity, but it has advantageous ecological and socio-cultural features, particularly in terms of biological diversity and landscape aesthetics. Accordingly, it finds strong acceptance among the general public, such that subsidised eradication programs have been abandoned and, in a number of countries, streuobst is now supported by non-governmental organisations and by state conservation policies. Modern agroforestry in temperate, industrialised countries should be oriented towards the creation of similar ecological and socio-cultural benefits in order to receive public support as a land-use system. This revised version was published online in June 2006 with corrections to the Cover Date.     

Participatory technology development in agroforestry: methods from a pilot project in Zimbabwe

An on-farm agroforestry pilot project was initiated by the Zimbabwe Forestry Commission in 1988. The main objective of the project is to investigate a range of options to solve problems of woodland depletion faced by small-scale farmers. This paper describes the first two years of on-farm experimentation. The first season's trials are described, and the rationale for moving towards an approach of greater farmer participation in the research process is given. Steps taken to promote experimental tree planting on farms are described, and methods used are illustrated by examples from the project. Critical awareness-raising techniques, steamming from Freirian philosophy, have been central to the methods. The need for a partnership between formal and informal farmer-based research is discussed, as is a model for agroforestry research and development. The latter is proposed in a way that formal research develops the components of agroforestry practices, whilst farmers are encouraged to experiment with a combination of these components in order to develop practices appropriate to local conditions.     

A mathematical model for generating land-use allocation alternatives for agroforestry systems

Agroforestry has been considered a viable land-use system particularly in the tropical regions. In developing or designing agroforestry systems, various concerns have to be addressed namely: (1) economic; (2) biological and physical; and (3) silvicultural and ecological considerations. This paper addresses these concerns from an interdisciplinary perspective. A land-use allocation model which ensures the simultaneous consideration of these concerns is proposed.     

Evaluating agroforestry interventions in extension projects

Because of the relative dearth of scientific information in agroforestry, monitoring and evaluation of agroforestry technologies in development projects plays an important role in the development and improvement of technical extension recommendations. To identify appropriate methodologies, ICRAF conducted in 1988–89 a review of agroforestry technology monitoring and evaluation in 166 projects worldwide, of which 108 responded. Almost 80% of these were involved in technology evaluation. Many extension projects were conducting research to test technologies on-farm or on research plots. Technology evaluation by projects focused on the biological of trees, often with inadequate consideration of the technology context. Few projects seemed to use farmer assessment in evaluation. Recommendations are made for an effective evaluation process and selection of appropriate methods and variables to be assessed by projects. Methods should be selected according to the availability of resources and should favour collaborative or collegial interaction between farmers and project staff.     

Eucalyptus in agroforestry: its effects on agricultural production and economics

The economics of eucalyptus in agroforestry and its effects on agricultural crops have been studied with the help of observations made during the harvests in agricultural fields and from the information supplied by progressive farmers. Three rotations of eucalyptus in agroforestry were selected for comparative study of its returns and relative loss to the crops, in order to ascertain the optimum rotation: i.e. the one giving the maximum internal rate of return with minimum loss to agricultural crops.     

The role of extension in agroforestry development: evidence from western Kenya

The extension strategy used by the CARE International in Kenya Agroforestry Extension Project (AEP) is described. This strategy is evaluated in terms of documented changes in farmer's agroforestry practices and the importance of AEP relative to other changes in economic incentives, institutional support, and land use and tenure rules for agroforestry. The project served mainly to increase awareness of the multipurpose potential of agroforestry, expand available technical options, and strengthen local institutions. Its community-based extension approach was more suitable for local conditions than commodity-based, training-and-visit, farming systems, or media-based extension. Projects are encouraged to tailor extension design to local circumstances, use community participation to guide extension priorities, and use extensionists as catalysts and information brokers.Research undertaken while the author was a Principal Scientist at the International Council for Research in Agroforestry, Nairobi, Kenya.     

Toward a rationally robust paradigm for agroforestry systems

Because people need improved agroforestry and because there are perceived limitations in a largely scientific approach to agroforestry research and development in the past, an alternative paradigm to gaining knowledge for use in this area is suggested. It is an encompassing approach to gaining knowledge which we call the rationally robust paradigm, RRP. The paradigm has 11 components: 1. Concentrating on site-specific knowledge, often in a geographic information system; 2. being aware of the limited funds to achieve agroforestry objectives; 3. de-emphasizing induction and deduction, and their replacement by or addition of other epistemological bases; 4. accepting lower confidence levels for conclusions and subsequent action; 5. using estimates of median values; 6. using knowledge of the range limits of agroforestry phenomena and factors; 7. giving attention to the system's phenomenon of equifinality and its consequences; 8. de-emphasizing time as a factor in system analysis, and replacing it with other system phenomena; 9. using statistical regression techniques but simultaneously seeking to identify and use independent factors (e.g., solar radiation) that function significantly in many models; 10. appropriately using regression techniques emphasizing the use of hypothesized, often-non-linear relationships; and 11. operating in a conceptual clinical milieu. The paradigm is proposed for use throughout agroforestry.     

On-farm agroforestry research in extension programmes: methods used by BAIF in India

The BAIF Development Research Foundation initiated an agroforestry extension project in Pune District, India in 1984, following earlier on-station research on leuceana-based alley-cropping systems for fodder. In extension meetings, farmers expressed a strong preference for planting a wide range of multipurpose trees on farm bunds and borders rather than single-species alley-cropping. Researcher-managed trials of proposed multipurpose species grown with crops were initiated, but were of limited value. An alternative approach to research was begun in 1988. This approach included a survey of agroforestry practices established by farmers through extension, and collection of data on crop yields by distance from the tree line from a sample of these plots. Research methods are described and modifications suggested for improving the quality of this type of extension-based research.     

Shifting from simple to complex agroforestry systems: an example for buffer zone management from Kerinci (Sumatra,Indonesia)

Kerinci is a densely populated valley surrounded by a national park in western central Sumatra, Indonesia. Indigenous agroforestry systems include important cash crops like coffee (Coffea canephora var.robusta) and cinnamon (Cinnamomum burmani), and range from alternate cycles of cash crop monocultures or simple associations, to multispecies and multi-storey gardens; these may include as many as 100 common useful species, comprising many fruit trees and indigenous timber species.After analysing the trends of forest conversion and its causes in the area of Kerinci Seblat National Park, a case study of one particular village is presented in order to describe the evolution of cyclic agroforestry systems (ladang) into complex agroforestry systems (pelak). The composition, structure and management of the various systems have been studied through interviews, botanical surveys and the method of profile diagrams.It is suggested that locally developed complex agroforestry systems evolve partly in response to changes in land availability and labour constraints. Finally the interest of such systems when designing projected buffer zones and their development in relation to new market incentives are discussed.     

Development and validation of a simple approach to modelling tree shading in agroforestry systems

There have been a number of models developed which attempt to predict the shading patterns beneath individual tree or forest canopies. We describe a computer-based model which is able to estimate shading patterns through a discontinuous canopy of pruned trees. The model is designed to assist in the layout and management of agroforestry systems with widely spaced trees. The model was tested against data collected from a seven-year-old agroforestry system involving radiata pine, located near Canberra, Australia. The model was shown to slightly but consistently underestimate light penetration at ground level beneath the trees. However, the extent of bias (0.7% to 5%) was so small as to be of little significance in practice.     

Do socio-psychological factors matter in agroforestry planning? Lessons from smallholder traditional agroforestry systems

Most of the well planned rural development forestry programs of the 1970s, and agroforestry in particular, were either not adopted by the intended beneficiaries or failed to meet the needs and aspirations of the rural people, particularly in the developing countries. The reasons for non-adoption in some cases appear to be technical, bio-physical, social and economic (termed as rational reasons by the planners), but in other situations the reasons are not so easily recognisable and comprehended (termed irrational reasons). These irrational reasons are the perceptions and attitude of the farmer towards farm practices, and their role in agroforestry planning has remained almost completely neglected. The present study is based on a household survey of the farmers in traditional agroforestry systems of Western Himalaya and investigates the importance of perceptional and attitudinal aspects of the farmers with regard to agroforestry adoption and extension. In the present study, farmers’ perceptions of restrictions on felling of trees from their own land and attitudes towards agroforestry were the most important sociopsychological factors which influenced tree growing. This study implies a need to take into account the socio-psychological factors of the farmers for planning socially acceptable agroforestry programs. The importance of study of various de jure rules and regulations controlling the use of on-farm tree resources and related exemptions and their association with farmers’ perceptions and tree growing is highlighted to develop policies to encourage tree growing in agroforestry.     

Surveying farmers' agroforestry plots: experiences in evaluating alley-cropping and tree border technologies in Western Kenya

Evaluation of existing on-farm agroforestry plots should provide useful supplementary information for the design of improved agroforestry systems, in both research and development projects. Such evaluation has been little used, however, largely due to the methodological difficulties of surveying highly variable on-farm plots, and difficulties in identifying key variables for measurement. This paper describes a set of methods and tools used in evaluating plots of alley-cropping and tree borders around crop fields established by farmers working with the CARE Agroforestry Extension Project in western Kenya. Details of survey design, sampling, and implementation are discussed, and suggestions made for carrying out agroforestry surveys in other projects. A condensed version of the questionnaire is appended.     

Benefit-cost analysis of selected agroforestry systems in Northeastern Thailand

Potential productivity and financial returns from selected agroforestry systems and traditional monocrops located in the Phu Wiang watershed were estimated from limited trials of cropping alternatives using cost-benefit analysis. The agroforestry systems studied consisted of combinations of Eucalyptus (Eucalyptus camaldulensis), Leucaena (Leucaena leucocephala), or Acacia (Acacia auriculiformis) inter-cropped with cassava (Manihot esculenta) or mungbean (Vigna radiata). Evidence from trials at short, 3-year rotations, demonstrate that early supplementary and complementary relationships between some system components can imply synergistic financial gains. Although these biological interactions turn competitive over time, in this case, the gains should be sufficient to make early adopters consider the agroforestry systems financially preferable to traditional monocrops.     

Technology impact evaluation in agroforestry projects

To identify appropriate methods for evaluating the impact of new agroforestry technologies, ICRAF in 1988–89 contacted 166 projects worldwide about their activities in agroforestry technology monitoring and evaluation. Of the 108 which responded, 45% were involved in some type of impact evaluation. This review revealed common difficulties in selecting impact indicators and methods of evaluation. Emphasis to date has been on evaluating numbers of trees planted and area under agroforestry, rather than socioeconomic impacts. Defining agroforestry adoption and distinguishing intermediate and final impacts were problematic. Impact studies were often difficult to interpret or compare, limiting their value for the rest of the agroforestry community. An analytical framework for planning impact evaluation in agroforestry projects is proposed, based on lessons learned from the review. Selection of indicators should depend upon whether project objectives relate to changes in: number and type of trees grown, land use, farmer knowledge and attitudes, availability of agroforestry products and services, and/or socioeconomic welfare. Data collection tools may include sequential photography or mapping, informal or formal farmer surveys, informal or formal field surveys, farmer meetings and workshops, trend analysis of project records, and case studies of households or communities, depending upon the audience for project evaluation and project resources.     

Tree crop based agroforestry in Nigeria: a checklist of crops intercropped with cocoa

A survey of cocoa farmers in Bendel, Ogun, Ondo and Oyo States of Nigeria, carried out in 1985, showed that almost all the farmers intercropped other crops with cocoa. The intercrops included food crops such as plantain (92.3), cocoyam (85.7%), cassava (51.3%), yam (41.3%), maize (38.9%), melon (31.4%), cowpea (28.6%) and pineapple (26.0%) and tree crops such as oil palm (71.5%), kola (67.3%), coffee (41.0%), coconut (7.9%) and citrus (7.2%). Other crops are ewe-iran (Sarcophrynium brachystachys) and ewe-gbodogi (Megaphrynium macrostachyum) (45.2%), african walnut (Tetracarpidium conophorum) (42.2%), aligator pepper (Aframomum melegueta) (31.6%), and iyere (Piper guinense) (20.2%). Guava, mango, pawpaw and vegetables such as celosia, okra and solanum occur in cocoa plots at rather low frequencies. As many as six or more other crops can be intercropped with cocoa at the same time.     

Farmer perspectives on agroforestry opportunities and constraints in cape verde

In the água de Gato Watershed on the island of Santiago, Cape Verde Islands, 51 farmers were surveyed regarding their attitudes and knowledge of agroforestry. The farmers identified eight constraints to agroforestry implementation, with virtually all indicating that a source of loan funds was the major concern. Space or land constraints and availability of tree seedlings were identified as constraints by 94% and 88%, respectively. Despite these concerns, 92% of the farmers expressed a willingness to adopt or improve agroforestry practices in the watershed, with 73% expressing a willingness to establish fruit trees, 53% willing to establish trees or shrubs for fuelwood, and 16% willing to plant trees for shade.