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.     

Modelling of rainfall interception loss in agroforestry systems

Two models of interception loss have been tested against new field data obtained in widely-spaced stands of Sitka spruce trees. The Gash model and a modified version of the Rutter model, have been used with data from an automatic weather station, to predict interception loss using parameters obtained from observations made in 1988 and 1989. The predictions for an eight-week period during 1987 were compared with measurements of interception loss. Good agreement between observed and predicted interception loss was obtained with both models over the whole period. The modified Rutter model gave better predictions than the Gash model for individual storm events and performed better at the wider spacings. The sensitivity of both models to the major characteristics of the tree stand structure in agroforestry systems was also investigated and it was shown that interception loss was most sensitive to boundary layer conductance and free throughfall coefficient.     

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.     

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.     

Traditional tree crop based agroforestry in coffee producing areas of Harerge,Eastern Ethiopia

A preliminary survey of seven coffee producing Awrajas (Provinces) in eastern Ethiopia revealed that there is a traditional tree crop based agroforestry system being practised by the farmers. Coffee (C. arabica) was found to grow under the shade of several trees, 16 species, usually intercropped by one or several, a total of 15, important grain, fruit, vegetable, stimulant, oil-seed and spice crops. The majority of the trees, 69%, is leguminous and Ficus spp. The system is characterized by the integration of crops, livestock and sometimes apiculture. Recommendations are made for future studies.     

A computerized database as decision support tool for the selection of agroforestry tree species

Whether in agroforestry in temperate or tropical zones, choosing the right species is one of the most crucial stages of experiments and for reforestation, erosion control or land-improvement projects.Over the last decade, ICRAF has developed a tool to help researchers, extension workers, foresters and others in the decision process. The Multipurpose Tree & Shrub Database (MPTS) contains information about more than 1,000 species. Most of these species are grown in the tropical and subtropical zones, but many of them have a potential for temperate areas as well.MPTS contains first-hand, site-specific information about multipurpose tree species. This information makes it possible for the user to compare his or her site conditions with the site conditions described in the database, and allows him/her to draw conclusions about the possible species performance. MPTS also contains secondary information from publications.Candidate species are searched by entering keywords from a list of 19 correlated criteria, such as soil information, expected services or wood and non-wood products. Detailed information about the selected candidates (e.g. morphology, management, environmental responses) is provided.Beyond this, MPTS is a quick reference tool for the multiple use of tree and shrub species. In future it will include a comprehensive guide to germplasm information. Current activities include the implementation of an interactive use-interface and links to related databases.     

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.     

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.     

The tree tenure factor in agroforestry with particular reference to Africa

Rights over trees are often distinct from rights over land. Tree tenure consists of a bundle of rights over trees and their produce which may be held by different people at different times. These rights include the right to own or inherit trees, the right to plant trees, the right to use trees and tree products, the right to dispose of trees and the right to exclude others from the use of trees and tree products. Factors affecting who had rights include the nature of the tree, the nature of the use and the nature of the person or group. Landowners and tree plants tend to be relatively advantaged in terms of their rights to trees. Those with temporary claims to the land and, in some case, women, tend to be disadvantaged. The implications of tree tenure issues for the design of agroforestry projects are discussed.

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Resumen Los derechos sobre los arboles muchas veces son distintos a los derechos sobre la tierra. La propiedad del arbol consiste en un lote o derechos sobre arboles y sus productos que pueden ser mantenidos por distintas personas en distintos tiempos. Estos derechos incluyen el derecho a poseer o heredar arboles, el derecho a plantar arboles, el derecho a usar arboles y los productos arboreos, el derecho a disponer de los arboles y el derecho a excluir a otros del uso de los arboles y los productos arboreos. Se incluyen en los factores que afectan quienes tienen determinados derechos la naturaleza de los arboles, la naturaleza de su uso y la naturaleza dela persona o grupo. Terratenientes y plantadores de arboles tienden a tener ventajas en terminos de sus derechos sobre los arboles. Aquellos con derechos temporales y en algunos casos las mujeres tienden a estar en desventaja. Aqui se discute la problematica de las implicancias de la tenencia de los arboles para el diseno de proyectos silvo-agropecuarios.

     

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.     

Perennial crop-based agroforestry systems in Northeast Brazil

Land use systems in the Northeast Region of Brazil are dominated by large holdings and extensive cultivation of perennial crops such as cashew, coconut, carnauba wax palm, babaçu palm and so on. The common feature which links these crops is the silvopastoral system of livestock (chiefly cattle, sheep and donkeys) grazing under them. Agrosilvicultural systems involving cultivation of annual subsistence crops, and in some instances other perennials, in the stands of these perennial crops is also common. The paper presents the available information on the management, production, rate of growth, economic importance, etc. of these agroforestry systems involving cashew, coconut and carnauba palm. These systems are of considerable merit in the environmental, agricultural and socio-economic conditions of Northeast Brazil. However, practically no research nor even systematic data collection has been done on these so that there is an almost total lack of information on them. In order to improve the systems, they should be studied in detail and research undertaken on various components (crops, trees and livestock) individually as well as the system as a whole. Selection of suitable species of grass and other herbaceous crops, appropriate management techniques for both overstorey and understorey species in relation to the age of the overstorey species, optimal stocking rates of animals, etc. have to be determined so as to enable plantation owners and operators to realize the full potential of these systems.     

Implementing on-farm agroforestry research: lessons learned in Talamanca,Costa Rica

The rapid appraisal and farmer selection procedures, preceding the establishment of over fifty agroforestry research trials on farms in Talamanca, Costa Rica are described. The highest probability of success and impact of these long-term collaborative trials is obtained by selecting innovative, experienced, motivated and locally respected farmers. The methodological lessons learned from implementing three types of researcher managed trials (shade-cacao; black pepper on living support posts; timber production in boundary lines) are discussed. The importance of fitting farmer selection criteria to project objectives, experimental designs to on-farm limitations, and project goals to farmers' goals, are emphasized.     

Bio-amelioration of alkali soils through agroforestry systems in central Indo-Gangetic plains of India

A long-term field study was initiated during 1995 at Central Soil Salinity Research Institute, Regional Research Station, Lucknow(26°47′58′′ N and 80°46′24′′ E) to analyze the effect of agroforestry systems on amelioration of alkali soils. Three agroforestry systems(pastoral, silvipastoral and silvicultural) were compared with the control where no agroforestry system was introduced. Tree-based silvicultural and silvipastoral systems were characterized by tree species Prosopis juliflora and Acacia nilotica along with grass species Leptochloa fusca, Panicum maximum, Trifolium alexandrium and Chloris gayana. Growth of ten-year-old Prosopis juliflora and Acacia nilotica planted in combination with grasses was significantly higher over the silviculture system with the same species. Tree biomass yields of P. juliflora(77.20 t?ha-1) and A. nilotica(63.20 t?ha-1) planted under silvipastoral system were significantly higher than the sole plantation of(64.50 t?ha-1 and 52.75 t?ha-1). Fodder yield under the pastoral system was significantly higher than the silvipastoral system during initial years but it was at par with that of silvipastoral systems after eight years of plantation. The microbial biomass carbon in the soils of silvipastoral systems was significantly higher than in soils under sole plantation of trees and control systems. The Prosopis-based silvipastoral system proved more effective in reducing soil pH, displacing Na+ from the exchange complex, increasing organic carbon and available N, P and K. Improvement in soil physical properties such as bulk density, porosity, soil moisture and infiltration rate was higher in the Prosopis-based silvipastoral system than in the silviculture system or control. On the basis of biomass production and improvement in soil health due to tree + grass systems, silvipastoral agroforestry system could be adopted for sustainable reclamation of highly alkali soils.     

The agroforestry potential of combined production systems in north-eastern Mexico

In the semi-arid to sub-humid north-east of Mexico, no definite agroforestry practices were in use before the Spanish conquest, but present systems and practices offer a good basis for conversion to ecologically sustainable and productive multicrop systems which incorporate trees. In the mountains and on the coastal plain of the Gulf of Mexico, sub-humid tropical tree crops are found in mixture with semi-arid, mediterranean and even temperate species. Irrigation systems are energy and labour intensive and can be improved. Of special interest for farmers without access to finance, are non-irrigated systems mostly derived from the low dry forest (matorral), which yield crops, fruit and wood for different purposes and also serve for depasturing cattle. These latter practices have high potential for development and optimization.Integrated Expert, Agroforestry, CIM, Germany F.R., GTZ Project No. 81.9008.4     

Structure and function of traditional agroforestry systems in the western Himalaya. I. Biomass and productivity

Species composition, biomass, and productivity patterns of three types of traditional agroforestry systems, namely, agrisilvicultural, agrihorticultural, and agrihortisilvicultural, commonly practiced in the western Himalaya, were studied. Species composition in the systems varied depending upon the size of the land holdings, and the basic requirements of the farmer. Among three systems agrihortisilvicultural was highly diverse in vegetation, with as many as 13 tree and 5 agricultural crops mixed together. This system showed the highest productivity up to 25.8 t ha⁻¹ yr⁻¹, out of which 68 percent was contributed by the trees and the remainder by the annuals. Agrisilvicultural system having predominantly annuals had the lowest productivity of 20.4 t ha⁻¹ yr⁻¹ with only 27 percent contribution by the trees. Total aboveground biomass in agrihortisilvicultural or agrihorticultural system was around 48 t ha⁻¹ and it was about 2-fold higher than agrisilvicultural system. In fodder trees, a significant percentage of annual production, up to 48 percent, was allocated in current twigs, while in horticultural trees a major portion, up to 63 percent was partioned towards fruits. Implications of the results have been discussed in context with the growing problems of fuel, fodder, and packaging material in the western Himalaya.     

Moisture extraction and crop yield as a function of distance from a row of Eucalyptus tereticornis

A study was made on the effect of an east-west tree line of years old Eucalyptus tereticornis on soil physical parameters and adjoining mustard and wheat crops as a function of distance from the tree-crop interface in north- and south-facing sides. Maximum soil temperature, pan evaporation, moisture extraction, number of plants/m², and yields of mustard and wheat did not differ significantly on the two sides of plantation. Plant growth parameters decreased linearly with distance from the plantation. Mustard yield, Y (kg/ha) was linearly related to moisture extraction, ME (mm) as Y = 1914–120.3 ME. Eucalyptus tereticornis was found to extract 5 times more water than mustard from 0–150cm soil profile. Mustard and wheat yield reductions in adjoining 10 meter strips on both sides of the plantation were 47 and 34 per cent, respectively. Eucalyptus tereticornis is, therefore, not a suitable species for row plantations in agro-forestry systems in deep water table conditions of semi-arid regions.     

Soil fertility and crop yields under improved-fallow systems in southern Mali

Improved fallows involving short-rotation woody and/or other perennial species are increasingly being tried as a means of sustaining crop production in impoverished farming systems of sub-Saharan Africa. The soil-improving potential of two tree species [Gliricidia sepium (gliricidia) and Pteocarpus erinaceus (pterocarpus)] and a shrubby legume Stylosanthes hamata (stylosanthes) was investigated in a four-year study on farmer's field and in a research station in the Koutiala region in southern Mali (12.25° N, 5.42° W; 650 to 850 mm annual, unimodal rainfall; on a Typic Plinthustalf). Two strategies for soil improvement were tested: improved fallow sensu stricto and biomass transfer, the former on-farm and the latter on-station. In the on-farm experiment, maize (Zea mays) yielded best when it followed a two-year fallow of gliricidia alone or in association with stylosanthes. On the research station, maize dry matter production and grain yields during two seasons following the application of ex-situ grown biomass were similar and highest in the stylosanthes- and manure-applied treatments. The biomass decomposition rates of the three species were in the order: gliricidia > stylosanthes > pterocarpus. The treatments did not have any significant effects on the soil fertility parameters that were monitored, possibly because of the short-term nature of the study. The treatments effects on crop yields were, however, significant. Gliricidia + stylosanthes in combination appeared to be particularly promising as short-rotation-fallow species in the region.This revised version was published online in November 2005 with corrections to the Cover Date.     

A tree/crop interface orientation experiment with aGrevillea robusta hedgerow and maize

Pruned triple-row hedges ofGrevillea robusta with 11 rows of maize planted in parallel on either side were grown in 12.5×16.0 m plots on a flat, freely exposed site. There were two replicates of four orientation treatments and crop yield was recorded row-by-row over 9 seasons. After the hedges had become established there were some marked differences in maize yields between sides, especially in the first rainy seasons. The maize on the downside of prevailing winds frequently showed improved growth and yield over the non-sheltered maize, sometimes by as much as 50% over the whole subplot and up to 80% in the tree/crop interface zone. These differences were significant (p0.05) when analyzing the whole experimental period for first and for second rainy seasons separately (prevailing winds more southerly or northerly, respectively), although they varied between seasons and zones. Attributing results to shelter can only be adduced circumstantially because meteorological data were not collected at the plot level. Shading effect were not considered important over the whole sub-plot. Soil water profiles obtained from an array of gypsum resistance blocks in two of the plots (at 000° and 090°) characterized the wetting and drying patterns in this system, but expected asymmetries due to orientation effects were not apparent except, perhaps, fleetingly in the topsoil. At the end of the experiment the distribution of fine roots of both species was examined by means of root trenching. TheG. robusta root system extended almost symmetrically to the edges of the plot in the uncropped part, but only to some 4 m from either side of the hedge where cropped. Part of the upper profile to 1.3 m was shared with the maize roots, butGrevillea rooted further down to at least 2 m. as well as rooting deeper. The possible implications of such niche differentiation for below-ground resource capture are noted.     

The scope and potential of agroforestry in Central America

Although agroforestry practices have been used in Central America since pre-Columbian times, scientific initiatives in agroforestry began only about 15 years ago in this region. This paper describes the evolution of agroforestry in the Central American region, and discusses the relative merits of generating new procedures or encouraging traditional practices. This is followed by an analysis of several particularly promising practices—use of N-fixing trees to shade cacao and coffee, timber trees in pastures, and living fenceposts. Finally, a list of research gaps and recommendations for future efforts is presented. It is concluded that, from the perspective of scientific knowledge, agroforestry in Central America has taken off but the link between scientific knowledge and effective field application is still lacking.     

Combination of cacao with other plantation crops: an agroforestry system in Southeast Bahia,Brazil

Brazil accounts for about 20% of the world production of cocoa, and about 95% of cocoa produced in Brazil is from the southeastern part of Bahia State. Traditionally, cacao is grown in monoculture (though under the shade of various other species). But various crop combinations involving cacao have recently been undertaken by the farmers with encouragement from Brazilian government.As a part of the crop diversification programme in the traditional cacao growing areas and their surroundings, extensive areas are being planted to other plantation crops, mainly clove and rubber and, to some extent, coconut too. Crop combinations have been adopted in some of these new plantings and cacao is an important component of most of such combinations. Whereas several other crops are combined with clove trees, cacao is usually the only species grown with mature rubber trees. Young rubber trees are, however, interplanted with a number of other species. Productive coconut areas are found mostly in sandy soils along the coast so that there is little intercropping. However, scattered farms are found where coconuts are underplanted with guarana, black pepper, cacao, cashew, etc. as done commonly in other parts of Northeast Brazil.