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.

     

Linking on-station research with on-farm testing: The case of agroforestry and organic matter-based cropping systems for the Rwanda farming systems improvement project

Hillside farming with its attendant erosion and decline in soil fertility is common-place in the area served by the Farming Systems Improvement Project. The project is designing land-use systems that would check erosion, increase soil organic matter and restore soil fertility. These systems will allow small farmers to increase or maintain product long-term basis without resorting to the use of high doses of inorganic fertilizers which are not readily available in the country. The use of leguminous shrubs and cover crops as nutrient sources — concepts embodied in agroforestry and organic farming systems — are options that landuse experts think might solve the problem. However, there is a dearth of knowledge about the biological feasibility of these interventions in the project area. This paper reports how FSIP combined problem diagnosis and analysis, researcher-managed adaptive trials and a field day to attack this lack of information. The rationale for using this approach is to address farmers' real needs, save time and minimize risk to poor farmers. This article is a contribution from the University of Arkansas' USAID-supported Farming System Improvement Project (FSIP) in Rawanda (USAID 696-0110), B.P. 625, Kigali, Rawanda. Authors are the project's soil scientist/agronomist and its extension and training specialist respectively.     

Linking on-station research with on-farm testing: The case of agroforestry and organic matter-based cropping systems for the Rwanda farming systems improvement project

Hillside farming with its attendant erosion and decline in soil fertility is common-place in the area served by the Farming Systems Improvement Project. The project is designing land-use systems that would check erosion, increase soil organic matter and restore soil fertility. These systems will allow small farmers to increase or maintain product long-term basis without resorting to the use of high doses of inorganic fertilizers which are not readily available in the country. The use of leguminous shrubs and cover crops as nutrient sources — concepts embodied in agroforestry and organic farming systems — are options that landuse experts think might solve the problem. However, there is a dearth of knowledge about the biological feasibility of these interventions in the project area.This paper reports how FSIP combined problem diagnosis and analysis, researcher-managed adaptive trials and a field day to attack this lack of information. The rationale for using this approach is to address farmers' real needs, save time and minimize risk to poor farmers.This article is a contribution from the University of Arkansas' USAID-supported Farming System Improvement Project (FSIP) in Rawanda (USAID 696-0110), B.P. 625, Kigali, Rawanda. Authors are the project's soil scientist/agronomist and its extension and training specialist respectively.     

Agroforestry farming systems in the homesteads of Kerala,southern India

Kerala State on the southwestern coast of India in the tropical humid zone has a predominantly agricultural economy, a very high density of population and therefore high pressure on cultivable land. The farmers there undertake cultivation of an array of crops — tree crops, plantation crops, seasonals and biennials — all in intimate mixtures on the same piece of land around the homesteads. Farm animals and poultry and sometimes fisheries also are essential components of the system. The close association of agricultural crops, tree crops and animals in the homesteads represents an excellent example of sustainable and productive agroforestry homegardens. Optimum utilization of available resources of land, solar energy and technological inputs and an efficient recycling of farm wastes are important characteristics of the systems. This paper attempts to describe and evaluate the systems' stability, productivity and sustainability, and identify its merits and constraints as well as research needs.     

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     

The Chagga homegardens: a multistoried agroforestry cropping system on Mt. Kilimanjaro (Northern Tanzania)

The homegardens are characterised by an intensive integration of numerous multipurpose trees and shrubs with food crops and animals, simultaneously on the same unit of land.The Chagga are skilled farmers with an intimate knowledge of the crops and their ecological requirements. They have a good idea of functions/uses of the plant species on their farms. The large species diversity provides both subsistence and cash crops. It enables the farmer to keep his management options open and provides insurance against drought, pest and economic risks.     

Comparison of the erosion control potential of agroforestry systems in the Himalayan region

The great erosion control potential of agroforestry systems is generally recognized. However, insufficient data are available to be able to give absolute quantitative values for the erosion control potential of specific agroforestry systems or to compare their potential. To obtain such quantitative erosion data, long-term standard erosion measurements should be done in specific agroforestry systems. Such measurements may become very costly because the data need to be collected in a wide range of agroforestry systems on different sites over a long time. A further constraint is the reliability of such information: erosion figures may not be comparable because of discrepancy between the scale of measurement and the scale of the agroforestry system and the occurrence of different kinds of erosion. The methodology presented here enables a quick comparative estimation of the erosion (surface erosion, gully erosion and mass movement) control potential of different agroforestry systems. The erosion control value of agroforestry systems is related to their protective functions: the cover, barrier and soil reinforcement functions. The methodology involves identifying which features influence these different functions within a specific agroforestry system and subsequently evaluating the efficacy. The applicability of this methodology is demonstated with examples from various agroforestry systems in the Himalayan region.     

Babassu palm in the agroforestry systems in Brazil's Mid-North region

Babassu palms (Orbignya spp.) cover nearly 200,000 km² in Brazil, providing cash income, fuel, fibre, edible oil and food to a large number of tenant farm households. Babassu is closely integrated within pastoral and shifting cultivation systems of Mid-North Brazil. In pastures, babassu provides shade for cattle, aids soil moisture retention, produces organic matter, generates supplementary farm income at little cost, and offers year-round employment. On the other hand, the persistence of juvenile palms reduces pasture grass productivity due to plant competition, and therefore there is a trend to eradicate babassu through clearcutting and understorey suppression. At moderate densities of less than 100 individuals per ha, mature babassu palms in cropland do not appear to harm crop productivity. In such cases, palms are thinned and leaves of the remaining ones are cut back, supplying fuel for the burn and nutrients to the soil. However, reduced fallow cycles due to pasture conversion threaten babassu as well as crop productivity.

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Resumo Palmeiras de babaçu (Orbignya spp.) occorrem em quase 200.000 km² no Brazil, proporcionando renda em dinheiro, combustível, fibras, óleo e alimentos para cerca de quinhentas mil famílias de pequenos produtores rurais, a maioria arrendatários ou posseiros. O babaçu aparece integrado dentro de sistemas de produção pastorís e de agricultura migratória no Meio Norte do Brazil. Nas pastagens, o babaçu provê sombra para o gado, ajuda na retenção da umidade no solo, produz matéria orgânica, gera renda suplementar com investimento mínimo, e oferece condições para fixar a força de trabalho durante a entressafra dos produtos agrícolas. A presença de palmeiras juvenís, porém, reduz a produtividade dos pastos devido a competição, o que leva os criadores de gado a erradicar o babaçu, suprimindo tanto as palmeiras juvenís, como as palmeiras adultas.No que diz respeito à agricultura migratória, o babaçu adulto em densidades moderadas, ou seja, até 100 indivíduos por hectare, aparentemente não reduz a produtividade das culturas anuais. Nestes casos, parte das palmeiras são desbastadas e as folhas das restantes cortadas, proporcionando combustível para a queima e nutrientes para o solo. No entanto, a redução nos ciclos de descanso devido à conversão das terras agrícolas em pastagens ameaça a produtividade quer do babaçu quer das próprias culturas.

     

The role of land tenure in agroforestry: lessons from Benin

In this article the relationship between land tenure and agroforestry is analysed drawing on a case study from Benin. It is argued that tenants, the landless and the majority of women are disadvantaged compared with landowners in terms of their ability to adopt agroforestry systems. This is due to a lack of land resources, tenure insecurity and restrictions in planting perennial crops. State interventions and conflicts between farmers and pastoralists further limit land tenure security of the rural population and thus reduce the willingness of peasants to invest on a long-term basis and to protect natural resources. The article concludes with some implications for policy and project interventions in the field of land tenure systems.

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Résumé Dans cet article, les relations entre droit foncier et agroforesterie sont analysées dans le cas du Bénin. Le fait que les locataires, les paysans sans terre et la plupart des femmes sont désavantagés par rapport aux propriétaires parce qu'ils ne sont pas en mesure d'adopter des systèmes agroforestiers est mis en evidence. Cela est dû au manque de ressources foncières, à l'incertitude de l'utilisation de la terre et aux restrictions sur la plantation des cultures pérennes. Des interventions étatiques et des conflits fonciers entre agriculteurs sédentaires et éleveurs restreignent la sécurité foncière de la population rurale et réduisent la disposition des paysans à investir à long terme et à protéger les ressources naturelles. A la fin de l'article les conclusions pour des interventions politiques et pour la planification des projets dans le domaine du droit foncier sont identifiées.

     

Alley cropping Sesbania sesban (L) Merill with food crops in the highland region of Rwanda

Food production in the densely populated Rwandan highlands is impeded by soil erosion and loss in fertility. Alley cropping leguminous shrubs with food crops on contours is purported to minimize the problem and to provide wood and forage. This study reports the effect of Sesbania prunings plus moderate levels of N and P on bean (Phaseolus sp) and maize (Zea mays) yields in alley cropping. Experimental design was a randomized complete block with split-split plots. Main plots were alley width: 2, 4, 6 and 8 m. Phosphorus (P) at 0, 30 and 60 kg P₂O₅/ha occupied the subplot and nitrogen (N) at 0, 30 and 60 kg/ha were assigned at the sub-sub plot level. No P was applied to maize during the second cropping season. Crop yield in kg/ha included the land space taken by hedgerows. Bean yield in 6 m alleys (1100 kg/ha) was about twice that in 2 m alleys (500 kg/ha). Bean responded to N and P. Optimum alley width and N for bean yield were 6 m and 30 kg/ha, respectively. Cuttings from alley hedgerows provided stakes for climbing beans. Maize responded to N but not to residual P. The highest maize yield came from 8 m alleys with 40 kg/ha, but yields from 8 and 6 m alleys with the same N treatment were not significantly different. Maize plants in middle rows were significantly taller than plants in rows adjacent to hedgerows. Maize rust development showed significant alley width and row position effect. There were significantly fewer uredinia in the Sebania alleys relative to the control plots without shrub hedgerows. Rust development on maize in middle rows was significantly greater than development in border rows.     

Adoption of mucuna in the farming systems of northern Honduras

In many parts of Central America long fallow periods are no longer feasible due to increasing land pressures. Farmers in northern Honduras have developed and diffused from farmer-to-farmer a maize cropping system using velvetbean (Mucuna spp.) as a short-term fallow. High total annual rainfall in a bimodal distribution is favorable to the system because it allows the completion of two rainfed cropping cycles annually. The first season is dedicated to the production of the mucuna crop and the second season is dedicated to maize. Soil pH and exchangeable Ca were not reduced during a 15-year period of continuous mucuna use. Soil organic matter, infiltration, and porosity increased with continuous mucuna use. Maize yields in fields with continuous rotation of mucuna were on average double those obtained without mucuna. The mucuna system was more profitable than the existing alternative bush-fallow system due to higher returns to land and labor resulting from higher yields, lower weeding and land preparation costs, and reduced risk of drought stress. The relative profitability of the mucuna system was also enhanced by seasonally high maize prices during the second season when maize is harvested in the mucuna system. Relatively easy access to land through inexpensive land ownership and land rental markets has made it possible for even small-scale farmers to dedicate land to the mucuna system. Land-use intensity is increasing in the region, however, as land is converted to pastures for cattle production. The opportunity costs of keeping land in the mucuna system, while also accessing land for first-season maize and other crops, are also increasing. These experiences remind us that a viable livelihood is the primary factor in farmers' decision making about adoption particular components of farming systems.This revised version was published online in November 2005 with corrections to the Cover Date.     

The economic impacts of agroforestry in the Northern Plains of China

In an effort to mitigate severe environmental problems, the Chinese government introduced ecological agriculture as an approach to sustainable grain production. One such method heavily employed in the Northern Plains of China is agroforestry. This region provides a unique case to assess the effect of agroforestry on agricultural output. This paper estimates a production function with a measure for forest cover to test the hypothesis that agroforestry makes a positive and significant contribution to agricultural output. Evidence shows that the effects of agroforestry on agricultural output are positive, though not always significant. This finding is relevant not only to Chinese agriculture, but also in answering the question of how agricultural sustainability can be accomplished in the long term. With increasing populations and decreasing opportunities for land expansion globally, agroforestry is one answer to improving agricultural growth.     

湖南退耕还林主要造林模式研究

湖南省自2000年开展退耕还林试点,2002年在全省全面实施,6年来各地在退耕还林实践中创造出了一批成功的造林模式,取得了良好的生态、经济和社会效益。通过总结湖南省主要退耕还林造林模式的技术措施,分析其生态和经济效益,走生态、经济、社会共同发展之路,确保退耕还林工程“退得下,还得上,能致富,不反弹。”     

Financial evaluation of smallholder timber-based agroforestry systems in Claveria, Northern Mindanao, the Philippines

In the Philippines, timber production on small farms has become profitable as a result of reduced supplies due to extensive deforestation and increasing demand. In the early 1990s, when the price of timber was high, farmers were promised huge returns from tree farming. However, widespread planting of few species has led to oversupply and a sharp decline in the price of farm-grown timber. Moreover, low intercrop yields as a result of competition from fast-growing trees and low timber yields due to poor tree management, further reduce net economic returns. In spite of this, interest in tree farming remains high. This paper examines the private profitability of two tree-maize systems, namely trees in blocks and trees in hedgerows, compared with the alternative of maize monocropping. The analysis reveals that maize monocropping provides higher returns to land at the current timber price, but considerably lower returns to labour, than the maize-tree systems tested. This suggests that tree farming is a more attractive option for labour and capital-constrained households or those with off-farm opportunities that compete for their labour. These farmers may raise productivity and income by planting trees on the excess land that cannot be devoted to annual crops. The analysis also indicates that wide-spaced tree hedgerows are superior to tree blocks, due to lower establishment and management costs, longer periods of viable intercropping and more rapid tree growth.     

Biodiversity and socioeconomic factors supporting farmers' choice of wild edible trees in the agroforestry systems of Benin (West Africa)

Wild edible trees are expected to play a significant role in the crop diversification programs and agroforestry development in Africa. In the present study, the diversity of wild food species and socio-economical factors that support farmers' choice for the species used in these systems were assessed. A number of selected sites in each of the 3 climatic zones of Benin were surveyed. Data were collected through a field exploration and a semi-structured survey among 435 selected households throughout the country, using a questionnaire. The most culturally important species ranked by locals were determined for each climatic zone and the relations between the targeted species in traditional agroforestry systems and the reasons which support peasants' choices were described through a Principal Component Analysis. A total of 43 wild edible trees were found in the traditional agroforestry systems of Benin during the survey. Traditional agroforestry systems in the Guineo-Congolian zone turned out to be the most diversified with 29 species followed by the Sudanian zone with 22 species and Sudano-Guinean zone with 16 species. The most culturally important wild edible trees in traditional agroforestry systems in the Guineo-Congolian zone were different from those identified in Sudanian and Sudano-Guinean zones. Three main reasons that support peasants' ambition to conserve or to grow wild edible trees in their field were: their contribution to food, their use in traditional medicine and ceremonies and the farmers' perception of their availability in natural vegetation.     

四川省退耕还林模式初探

根据自然地理分异规律、社会经济技术原理、生态学原理,分析了四川省的水土流失概况,提出了川中丘陵、盆周山地区、川西南干热干旱河谷区、川西北高山高原区的退耕还林模式。     

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.     

Modelling agroforestry systems of cacao (Theobroma cacao) with laurel (Cordia alliodora) and poro (Erythrina poeppigiana) in Costa Rica

The agroforestry systems of cacao (Theobroma cacao) under laurel (Cordia alliodora) and cacao under poro (Erythrina poeppigiana) were studied at CATIE, Turrialba, Costa Rica. An inventory was taken of the organic matter and nutrients (N, P, K, Ca, and Mg) separating the species into their compartments (leaves, branches, trunks and roots). Studies of the litter and of the mineral soil (0–45 cm) yielded these results: Patterns of nutrient accumulation are discussed in relation to the characteristics of these agroforestry systems.     

退耕还林对土壤抗冲能力的强化效应

抗冲性是土壤生态系统在抵抗面状侵蚀和线状侵蚀过程中所表现出的一种重要性能,主要受植物群落和土壤特征的影响。通过采用索波列夫抗冲法试验,结果表明:①退耕还林3年后,林地10、30、50 cm三个土层的平均产流历时比坡耕地延长1.2、0.87、0.52 s,地表迳流量比坡耕地减少5.216、4.286、2.613 L/m2,土壤抗冲性比坡耕地增强0.277、0.255、0.206 kg/(m2.min);②土层越深,退耕还林对土壤产流历时的延长效应就越短,对土壤产流量的减弱效应就越小,对土壤抗冲性的强化效应就越低;③退耕还林对坡面产流历时的延长效应、对坡面产流量的减弱效应及对土壤抗冲性的强化效应随土壤母质的不同而差别很大。