On-farm Agroforestry Research Articles

Allometric equations for estimating on-farm fuel production of Gliricidia sepium (Gliricidia) shrubs and Cajanus cajan (pigeon pea) plants in semi-arid Tanzania

BackgroundFuelwood is considered to be the primary source of cooking energy in Tanzania and, due to ongoing deforestation, access to fuelwood is becoming more cumbersome. On-farm agroforestry systems can reduce dependency on off-farm fuel; however, the output of on-farm produced fuel is typically uncertain as production potentials are often not known. In this paper, we have developed allometric equations to model the above-ground woody biomass (AGWB) production from intercropped Gliricidia sepium (Jacq.) Kunth ex Walp (Gliricidia) shrubs and Cajanus cajan (L.) Millsp. (pigeon pea) plants.MethodsWe used a destructive sampling approach, for measuring the dendrometric characteristics, such as the root collar diameter at a 20 cm stem height (RCD20) and the stem height to estimate the AGWB production. The models are based on 112 Gliricidia and 80 pigeon pea observations from annually pruned plants. Seven allometric equations were fitted to derive the best-fit models for the AGWB production.ResultsWe found that using a natural log-transformed linear model with RCD20 as a single predictor variable provides the highest explanatory value to estimate the AGWB production (Gliricidia: R2 = 95.7%, pigeon pea: R2 = 91.4%) while meeting Ordinary Least Square (OLS) estimator requirements. Adding stem height as an additional variable to predict the AGWB production does not improve model accuracy enough to justify the extra work for including it.ConclusionsWhile on-farm pigeon pea plants produced a stable amount of woody biomass per annum, annual fuelwood production from Gliricidia shrubs increased over the years. Compared to the annual fuelwood consumption data from the literature, our results show that on-farm produced fuelwood can substantially offset the demand for off-farm fuel, potentially resulting in household fuelwood autarky.

Diversity and Aboveground Carbon Sequestration Potential of On-Farm Agroforestry Trees/shrubs Species in Rajaf County-South Sudan

Agroforestry (AF) trees have the potentials to sequester carbon in most farming systems especially in the face of the current climate change. The objective of this study was to estimate the diversity, abundance, and aboveground carbon sequestration potential of onfarm tree species in four different sites, Tokiman, Gumbo, Kolye West, and Kolye East with various agroforestry practices in Rajaf County, South Sudan. Three hundred and fifty-five AF trees were inventoried by non-destructive methods for diameter at breast height (DBH), height (H) and Crown width (CR) variables. Aboveground biomass analyzed using allometric models was converted to carbon stocks. The Shannon-Weiner indices for the AF sites indicated that C. limon, M. indica and P. guajava were more diverse in Tokiman and Gumbo sites. T. grandis was more diverse in Kolye East and Kolye West, with S. siamea only diverse in Kolye West. The diversity analyses also showed low values of (H’) for Gumbo and Tokiman as compared to those calculated for Kolye West and Kolye East. In addition, high levels of aboveground carbon sequestration were observed in Gumbo and Kolye East sites where tree species were relatively abundant. Kolye West, on the other hand, had very few but highly dominant AF tree species while Tokiman Islands with the most planted tree species had a rare agro-ecology that contributed less or nearly zero to aboveground carbon sequestration.

Strategy to improving community economic through on-farm agroforestry using community forestry scheme in KPH Yogyakarta

The enhancement of land productivity using the agroforestry mechanism with the scheme of community forestry program has been practiced as a strategy to improve the economic growth of the community surrounding Kesatuan Pengelolaan Hutan (KPH) or Forest Management Unit of Yogyakarta. This approach is expected to become the solution in reducing deforestation and degradation as impacts of the decreasing quality of forest resources. Forest co-management with the community through a commodity diversification scheme has been practiced for several years. The objective of this research is to understand the economic profile of the farmers’ households who have become part of the program using several parameters. These parameters include the financial feasibility of the agroforestry scheme, the economic contribution from on-farm and off-farm income to farmers’ total income in a specified period, and the discrepancy between farmers’ income, and income per capita as initial input to measure the social-economic level in regional basis. From 100 respondents interviewed, we could provide the following information: (a) the farmers as respondents are categorized into four land share areas, namely (a) ≤ 0.25 Ha (b) 0.26-0.50 Ha (c) 0.51-0.60 Ha and (d) 0.61-1.00 Ha. The average income in Gunungkidul District for (a) Production forest is 1,612,500 IDR (b) Conservation forest is 1,893,750 IDR while the average income in Kulon Progo District for (a) Production forest is 1,568,250 IDR and (b) Conservation forest is 1,612,500 IDR. The income from areas managed by the farmers as stated above represent the economic contribution from the on-farm and off-farm income of the program. The income contribution for farmers from agroforestry within the research remains low (<10%), and the income discrepancies calculated using the Gini Ratio coefficient are (a) 0.38-0.42 for Gunungkidul District and (b) 0.34-0.46 for Kulon Progo District. Both of the regions studied have low to moderate discrepancy levels.

Selection of native trees for intercropping with coffee in the Atlantic Rainforest biome

A challenge in establishing agroforestry systems is ensuring that farmers are interested in the tree species, and are aware of how to adequately manage these species. This challenge was tackled in the Atlantic Rainforest biome (Brazil), where a participatory trial with agroforestry coffee systems was carried out, followed by a participatory systematisation of the farmers experiences. Our objective was to identify the main tree species used by farmers as well as their criteria for selecting or rejecting tree species. Furthermore, we aimed to present a specific inventory of trees of the Leguminosae family. In order to collect the data, we reviewed the bibliography of the participatory trial, visited and interviewed the farmers and organised workshops with them. The main farmers’ criteria for selecting tree species were compatibility with coffee, amount of biomass, production and the labour needed for tree management. The farmers listed 85 tree species; we recorded 28 tree species of the Leguminosae family. Most trees were either native to the biome or exotic fruit trees. In order to design and manage complex agroforestry systems, family farmers need sufficient knowledge and autonomy, which can be reinforced when a participatory methodology is used for developing on-farm agroforestry systems. In the case presented, the farmers learned how to manage, reclaim and conserve their land. The diversification of production, especially with fruit, contributes to food security and to a low cost/benefit ratio of agroforestry systems. The investigated agroforestry systems showed potential to restore the degraded landscape of the Atlantic Rainforest biome.

An Introduction to the Conservation of the Eastern Arc Mountains

It is 19 years ago, that I, as the organiser for the 4th East African Wildlife Symposium, which was hosted in Arusha by the University of Dar es Salaam, dared to add a section on forest biology and forest conservation. The conservation agenda then was concerned with issues of managing elephants and lions and other large hairy wildlife. Conservation then was about National Parks not Forest Reserves, it was about savannah grassland not forests, it was about elephants not camphor trees or African violets. Conservation then still had not got to grips with the involvement of people. Conservation was centred on wilderness areas, not on the people resource interface! Whilst the 1978 conference also had 150 participants from all over the world, few of them cared about forests. It is a sobering thought that today we can host a major conference on the Eastern Arc Forests alone! (Has the world changed? And are we about to see an era of real conservation?). In 1978, most participants were from overseas. In today's workshop, Tanzanians make up over half the active audience! It is instructive to think back 20 years and consider forest conservation issues in Tanzania in 1978: • The word 'conservation' was not in the University Forest Curriculum (not once!). • Forest students did not go to natural forests for training (not once in three years!). Logging and on-farm agro-forestry were the focus topics then. • Intense mechanical logging was underway in the East Usambara Forests, supported by government and foreign aid. • The word biodiversity did not exist. • The human population of Tanzania was half that of today, and the demand for forest products was less than half. Woodland resources were still available to meet much of that fuel wood need. • There were conservation arguments in the Usambara Forests. Much of the canopy had a cardamom understorey. We noted that Kenya with no cardamom growing areas exported twice our national output! • The Forest Department had money and capability-but little conservation concern. But now, there is much greater concern, but lost capacity and no money!

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.

On-farm research: the challenges of agroforestry

A review of recent experience in on-farm agroforestry research demonstrates that on-farm investigations may be usefully undertaken at any stage of research. Objectives may be to study existing agroforestry systems, to learn from farmers' knowledge, to access representative site conditions, or to elicit farmer evaluation of new technology. The weak scientific knowledge base about socioeconomic and technical aspects of agroforestry, the complexity of agroforestry systems, and the value of local farmers' experience make on-farm research unusually important in agroforestry.

Measuring crop yields in on-farm agroforestry studies

The paper describes the agronomic and statistical principles that form the basis for measuring crop yields in on-farm agroforestry studies. Agroforestry systems differ from agricultural systems because of the presence of tree/crop interfaces and the need for large plots, large borders and long-term monitoring. These differences accentuate the variability of crop performance on farms. Crop yield estimation per unit area in any agroforestry system involves essentially i) stratification of the plot into different, clearly distinguishable crop zones such as those under and free from the influence of trees, those on sloping and flat areas, and those on areas affected by pests, ii) drawing representative samples from each stratum, and iii) weighting the sample yields with weights proportional to the stratum area. The tree/crop interface areas may require further stratification and determination of yields of individual crop rows at different distances away from trees based on the nature and extent of tree/crop competition. The precision of yield estimation depends on how well one is able to define the strata as well as the variance of crop yields in space and time in each stratum. Studies that provide this information are urgently needed for developing practical recommendations for crop-yield measurements on farms.

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.

Understanding an indigenous knowledge system for tree fodder via a multi-method on-farm research approach

Understanding the dynamics of indigenous resource management systems can benefit natural resource development efforts and contribute to effective on-farm agroforestry research initiatives. This paper reports on the authors' investigation of an indigenous knowledge systems for the management, cultivation, and use of private tree fodder resources in a community in the middle hills of Central Nepal. It focuses on the methods used to develop an understanding of the cognitive systems used by farmers in this community to classify and evaluate tree fodder. A participatory multi-method research approach was employed to overcome many of the limitations of traditional survey research. The approach centered on the use of the repertory grid method within the framework of personal construct theory. Repertory grid results were analyzed in conjunction with data collected from participant observation, a formal household survey, an inventory of privately grown trees, and ethnographic interviews. This integrated analysis resulted in an understanding of the indigenous knowledge system for the management of tree fodder resources.

Farmer-augmented designs for participatory agroforestry research

Two factors suggest that experimental designs used in on-station research are not appropriate for on-farm agroforestry research. First, successful technology development and validation requires farmer participation, which in turn requires more flexible experimental designs for on-farm experimentation. Second, the advent of widely available statistical computer packages and computing power allows the experimenter to deviate from ‘standard’ design restrictions of complete blocks and full replication. Farmer involvement in the research process should include the opportunity for farmers to ask questions and to define treatments along-side those of the researcher.

Abstracts of other papers presented at the ICRAF International Workshop on “Methods for participatory on-farm agroforestry research”

Abstracts of other papers presented at the ICRAF International Workshop on “Methods for participatory on-farm agroforestry research”

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.

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.

Methodology for Woodfuel Development Planning in the Kenyan Highlands

The Kenya Woodfuel Development Programme (KWDP) has developed a three-tier approach to the study of rural woodfuel energy supplies. The methodology has evolved in the course of studying three districts (Kakamega, Kisii and Murang'a) in the densely-populated high- lands of Kenya between 1983 and 1986. The approach hinges on three elements: (1) district sub-regionalization based on low-level colour air- photography; (2) household questionnaire surveys based on a nested sample derived from the sub-regionalization; (3) a cultural survey through which prevailing attitudes to on-farm agroforestry and woodfuel issues are revealed. Additional aspects of the programme include a district-wide on-farm woody biomass survey based on the results of the air-photo survey and field work, and a farm typology which is being developed on the basis of all three surveys. Some of the more important conclusions which have emerged from this work include the following: (a) The integration of tree production into general farming activities is complex and deeply-rooted. Local farmers have an intimate knowledge of the benefits and weaknesses of the different trees growing in different situations on the farms. These are manifest in different ways among the sub-regions of the districts. (b) As a proportion of the total on-farm woody biomass, deliberately managed and planted woody biomass increases with increasing population density. (c) Contrary to expectations, as population density increases and farm size diminishes, the amount of land devoted to woody biomass production increases. In the southern third of Kakamega District, with rural population densities exceeding 700 per sq. km, more than 20% of the land is devoted to woody biomass. (d) Assuming an annual requirement of 1 m3 of wood per person, it is estimated that 31% of the district's farms experience a shortage of greater than 50% of needs. Only 21% have a surplus. Despite such a high proportion of land devoted to trees, the population densities are so high that these areas experience the greatest deficits.