Coffee-based Agroforestry Research Articles

Does adoption of agroforestry increase farm production and dietary diversity in the hills of Nepal?

There are few studies on the influence of agroforestry intervention in the farming and food system. We thus conducted this study to assess farm production diversity and household dietary diversity in the coffee-based agroforestry in Deusa village, Solukhumbu district, Nepal. This study collected data through questionnaire survey, food diary checklist for 24 hours diet recall, transect walk, focus group discussions, and key informant interviews. We compared farm production diversity and household dietary diversity scores between two agroforestry types - traditional and coffee-based. We used Pearson’s Chi-Square and Fisher’s Exact tests to assess the association between agroforestry type and 16 food groups wise consumption. Results showed that the farm production diversity is positively associated with the household dietary diversity. Among 16 food groups, households under coffee-based agroforestry system were more likely to consume dark green leafy vegetables (Chi square- 5.385; df=1; p<0.05), and descriptive statistics showed relatively higher consumption for most of the other food groups. It indicates that agroforestry intervention can be beneficial to improve farm production diversity and household dietary diversity in the longer run. Thus, agroforestry promotion is not only important in enhancing biodiversity and farm income but also equally vital in improving food and nutrition security for smallholders.

Assessment of coffee-based agroforestry system performance by provinces in the Central Highlands of Vietnam

Dominated by intensive coffee monocultures for the last 30 years, farmers in the Central Highlands of Vietnam has been increasingly experienced with farming difficulties given resource degradation, market and climate uncertainties. In recent years, a number of farmers have diversified their coffee farms toward the forms of agroforestry: through integrating fruit and other crops into coffee farms. This study, by referring to the existing 10 agroforestry systems and 10 forestry ecological zones identified in the region for its approach, conducted in 20 communes throughout five provinces in the region at the coffee harvesting period in the end of 2018. In total, 249 farmers were identified through snowball sampling technique and successfully interviewed. Five major agroforestry systems are identified with sufficient sample size for statistical analyses. By detailed assessment of inputs used and revenue, this study proves that agroforestry systems strongly enhance farmer’s income. However, the success varies among the five studied provinces. Farmer’s technical know-how and their choice on 2nd crop made their agroforestry farming profit largely different. Given the fact that large percentage of land in the tropics is too dry, too steep, or too rocky to be classified as arable land which has been further problematic through increasing exposure to erosion resulting from unsustainable farming practices, often driven by intensive monocultures, efforts to promote agroforestry in Vietnam in particular and the tropics in general is thus needed, not only for surviving increasing population but also recovering and protecting the environment. In the situation of the Central Highlands of Vietnam, together with efforts in promoting agroforestry, a restructure of farming system needs to be considered in accordance with foreseeable difficulties in farming conditions, i.e., more water stress will be happened in certain provinces. These provinces should take a shift more toward less-irrigation dependent crops and reduce their dependence on coffee. These changes will create a better common guarantee for all farmers in coping with future uncertainties.

Combining participatory games and backcasting to support collective scenario evaluation: an action research approach for sustainable agroforestry landscape management

The combined and interacting effects of land-use change, resource extraction and climate change threaten the sustainability of millions of mainly smallholder farms in tropical agroforested landscapes. In many of these landscapes, coordinated action among stakeholders at landscape level would help to address challenges such as pests and diseases, price crises and climate change. However, methods to facilitate the co-production of sustainable landscape management in such complex multi-stakeholder systems are currently largely lacking. In this paper, we present a novel approach to explore pathways for the sustainability transition of agroforestry systems. By combining participatory forecasting and backcasting approaches, based on serious games and future vision development, we explore relevant agroforestry management strategies for reaching sustainable future coffee-based agroforestry landscapes. We focused our research on the challenges faced in the main coffee-producing area in Nicaragua. Here, we organized five participatory game sessions to explore farmer decision-making processes, farming strategies and to develop new networks and stimulate social learning among farmers. In the associated backcasting workshop, the most influential game session participants joined technicians, researchers and municipality officials to collectively envision sustainable future landscape management. In all game sessions, farmers developed diversified coffee-based agroforested landscapes characterised by increased density and diversity of shade trees, for the purpose of income diversification as well as forest conservation. During the backcasting workshop, the participants identified policy instruments and community-based solutions for the transition to sustainable landscapes. Our participatory approach facilitated discussion on landscape planning among farmers and other stakeholders and allowed the outline of a pathway towards the collective envisioned future landscape. The combination of participatory forecasting and backcasting proved to be a helpful tool to support multi-stakeholder processes towards sustainable landscape management in this and other complex landscapes.

Analysis of interactions amongst shade trees, coffee foliar diseases and coffee yield in multistrata agroforestry systems

In complex coffee-based agroforestry systems, quantifying the impact of shade trees on coffee disease regulation and coffee yield is crucial for improving these systems and designing more sustainable ones. To this end, we analyzed interactions amongst shade trees, coffee plants (cv. Catimor), the coffee foliar disease complex and soil characteristics. We studied systems characterized by 40 variables measured in 60 plots located on three farms (monitored for 2 years) in Nicaragua. These variables characterized six system components grouped in six statistical blocks: shade trees (shade percentage and species abundancy), soil characteristics (fertility), foliar diseases, coffee plant characteristics (age and size), coffee growth and yield. We used partial least square path modelling (PLS-PM), i.e. a structural equation modelling approach used to understand and quantify interactions between the six blocks. Shade trees (mostly the associated shade percentage) had direct positive effects on foliar disease severity and incidence and soil quality, while having negative effects on coffee growth and yield. Soil characteristics (carbon, nitrogen, litter index, water infiltration potential) were negatively correlated with foliar diseases. An excessive shade percentage then had an indirect negative effect on coffee growth and yield due to the increased prevalence of foliar diseases. Finding the optimal shade cover can help reduce foliar diseases and enhance coffee berry production. The ‘dose effect’ of shade cover must also be considered because excessive shade, as well as lack of shade, have negative impacts on coffee growth and yield. Overall, effective shade management requires an analysis of trade-offs between soil quality, disease regulation and yield gains. In conclusion, PLS-PM turned out to be a good tool for studying agroecosystem networks and enabled us to put forward some foliar disease management and coffee yield enhancement guidelines.

Forest conflict mitigation through coffee-based agroforestry provide secure habitat for Javan Slow Lorise in a lowland fragmented forest in Central Java, Indonesia

Java Island has experienced numbers of forest conflict. Consequently, it may contribute to the disturbance of the sustainability of its forest biodiversity and increasing number of local poverty surrounding the forest area. Agroforestry system is known as one of the strategies to mitigate the forest conflict. The system helps the farmers to increase agricultural production, social life, and ecological stability. Local community in Kemuning forest had been implementing coffee-based agroforestry system for a long time, as part of their main income. This system allowed farmers to acces the forest through an intensive interaction between locals and its forest environment. This study aimed to understand the forest conflict mitigation through agroforestry practices in Kemuning forest better, which allegedly become a key factor for the sustainability of the presence of Javan slow lorise. This study builds on the assumption that people frame conflicts on Kemuning forest according to their experiences, expectations, objectives and interests at a specific moment. The basis for our analytical framework is found in theories on framing. In doing so, the study uses the framing analysis theory to identify framing of the conflict by different involved stakeholders. Data were collected in 2018 - 2019 through several techniques such as in depth interview, field observation, and study literatures. Collected data were analyzed descriptively by discussing each finding with framing analysis theory. Findings revealed that conflict in Kemuning forest were triggered by three main issue/problem frames identified as the root causes of the conflicts which are forest security, unfollow the signed contract, and an unequal benefit sharing from the coffee-based agroforestry sector. Other frames: identity, characterization, and conflict management frames were constructed in such a way to reinforce the issue/problem frames. This study also found that related to Javan slow lorise habitat, this coffee-based agroforestry system is the appropriate land use management that provide secure habitat for the sustainability of the presence of the animal within Kemuning forest.

Pengelolaan Agroforestry Berbasis Kemiri (Aleurites moluccana) dan Pendapatan Petani di Kecamatan Mallawa

This study aims to determine the management system, composition and income of candlenut-based agroforestry systems in three villages in the Mallawa District. This research was conducted in May - July 2019 in Batu Putih Village, Tellumpanuae Village, Samaenre Village, Mallawa District. The method used is purposive sampling with respondents, namely farmers who have ≥0.1 ha of land area. The number of plots made was 15 plots to determine the volume of wood and the number of respondents interviewed was 30 to determine the form of management. The data that has been collected is processed and analyzed descriptively and quantitatively. The results showed that the management of coffee-based agroforestry systems was initiated by clearing land from grass or shrubs, followed by spacing, then sources of seedlings obtained from government assistance and planting and maintenance which included weeding, pruning, fertilizing and pest control and diseases which then end with harvesting activities. The average for income in the Batu Putih Village of Rp. 24,372,359 -/ha/year, in the Village of Tellumpanue Rp. 27,875,042, -/ha/year, and the Samaenre Village in the amount of Rp. 22,985,365, -/ha/year.

Forecast models of coffee leaf rust symptoms and signs based on identified microclimatic combinations in coffee-based agroforestry systems in Costa Rica

Coffee leaf rust is a polycyclic disease that causes severe epidemics impacting yield over several years. For this reason, since the 1960s, more than 20 models have been developed to predict different indicators of the disease's development and help manage it. In existing models, standardized periods of influence of the meteorological predictors of the disease are determined a priori, based on strong assumptions. However, the appearance of a symptom or sign can be influenced by complex combinations of meteorological variables acting at different times and for different durations. In our study, we monitored a total of 5400 coffee leaves during a year and a half, in different agroforestry systems, in order to detect the onset dates of the disease symptoms, such as lesion emergence, and signs, such as sporulation and infectious area increase. In these agroforestry systems, we also recorded microclimate. We statistically identified the complex combinations of microclimatic variables responsible for changes in lesion status to construct three models predicting lesion emergence probability, lesion sporulation probability and growth of its infectious area. Our method allowed the identification of different microclimatic variables that fit well with the knowledge about the coffee leaf rust biology. Minimum air temperature from 20 to 18 days before a lesion emergence explained the status change from healthy to emergence of visible lesion, possibly because the short germination phase is stimulated by low temperatures. We also found a unimodal effect of rainfall over a period of 10 days, 33 days before lesion emergence, with a maximum at 10 mm. Below this threshold, uredospore dispersal is efficient, increasing the lesion appearance probability; above this threshold, wash-off effects on uredospores probably occurs, decreasing the probability of lesion emergence. In addition, we identified microclimatic variables whose influence on coffee leaf rust had not been described before. These variables are likely to be involved in the internal development phases of the disease in the coffee leaves: (1) unimodal effects of maximum air temperature in different periods on sporulation and infectious area growth (2) positive and unimodal effects of rainfall in different periods on sporulation and (3) a negative effect of leaf thermal amplitude in different periods on lesion emergence, sporulation and infectious area growth. Although these models do not provide predictors of the level of disease attack, such as incidence, they provide valuable information for warning systems and for mechanistic model development. These models could also be used to forecast risks of infection, sporulation and infectious area growth and help optimize treatment recommendations.

Shade tree Chloroleucon eurycyclum promotes coffee leaf rust by reducing uredospore wash-off by rain

Shade trees stimulate many pathways that influence disease development in opposite directions, and that, in addition, may interact with environment. To better understand shade trees effects on coffee leaf rust (CLR), we studied three disease stages separately: sporulation, uredospore wash-off by rain, and uredospore deposition on leaves. The study was conducted during almost one year in the long-term trial on coffee-based agroforestry systems established by CATIE in 2000, in Turrialba, a low altitude area of Costa Rica. We only used the Full Sun and Shade provided by Chloroleucon eurycyclum treatments. For studying sporulation, we harvested diseased leaves every three weeks and collected the uredospores present on the lesions. For assessments of uredospore wash-off, we located containers at ground level below the coffee bushes and in the interval between rows of coffee bushes, and removed them after rainfall events (43 rainfall events studied) to count the number of uredospores collected. For uredospore deposition, we used varnish to capture deposited uredospores on apparently healthy coffee bush leaves (55 dates). We also studied the raindrop kinetic energy by using splashcups, on 19 rainy days. The number of uredospores produced and preserved was 2.22 times higher below shade trees than in full sun, whereas the number of uredospores lost by wash-off, below the coffee bush, was 1.62 times lower. Reduced wash-off was probably due to raindrop interception by shade trees and stemflow and to the increased kinetic energy of the raindrops in the understory of the Shade treatment (twice as high as that measured in full sun), which reduced the capacity of coffee leaves to intercept raindrops. In addition, we found 1.43 times more uredospores deposited on apparently healthy leaves below shade trees than in full sun, partly due to the higher number of uredospores produced and preserved below shade trees. Increasing throughfall and reducing raindrop kinetic energy below shade trees seem crucial to improved CLR regulation. This can be achieved by selecting specific shade tree functional traits and by implementing shade pruning during the rainy season.

Marketing Efficiency of Coffee-Based Agroforestry Based on Market Performance: A Case of Study in Air Kubang Village, Tanggamus

The main sources of community income at Air Kubang village, Air Naningan sub-district, Tanggamus District is from the cultivation and marketing of robusta coffee (Coffea robusta) that is managed using an agroforestry system. Coffee-based agroforestry also contributed a positive ecological impact on the surrounding communities such as the preservation of springs that are utilized by the community to meet household needs. A study on coffee marketing is urgently needed to determine the efficient marketing channels based on the market performance of each channel. The purpose of this research was to identify marketing channels of robusta coffee and determine the performance of each marketing channel. Data were collected in December 2018 in Air Kubang Village, Air Naningan District, Tanggamus Regency. The data were obtained through interviews with respondents such as farmers and marketing institutions involved in the marketing of robusta coffee. Market performances were analyzed through the calculation of marketing margin, profit margin, profit margin ratio, share, and marketing efficiency. The study identified three marketing channels as follows: (1) farmers – collector traders – wholesalers – retailers, (2) farmers – cooperatives – retailers, and (3) farmers – cooperatives. Analysis of marketing efficiency (EP) showed that the three marketing channels were efficient with the EP values <1. However overall results showed that the marketing of coffee for the three marketing channels was not yet efficient, showing high marketing and profit margins, uneven distribution of profit margin ratio, and low share received by farmers.Keywords: agroforestry, marketing efficiency, marketing margin, robusta coffee

Enhancement of resilience to climate variability and change through agroforestry practices in smallholder farming systems in Cameroon

The impacts of climate variability and change are being felt by various sectors of economic life, especially the agricultural sector. It is for this reason that this study sought to investigate how agro-ecological and climate-smart systems like agroforestry could contribute towards enhancing the resilience of the agricultural sector in general and smallholder farmers in particular, faced with the climate change menace in Cameroon. Household and field surveys were the main primary data collection methods. Findings showed that variability and changes in climate parameters were real, and a plethora of agroforestry practices categorized into agrosilvicultural, silvopastoral and agrosilvopastoral systems were practiced by smallholder farmers. Agroforestry products and services like food, fuelwood, building materials, and erosion control were identified by smallholder farmers as contributing towards the strengthening of their resilience to climate change impacts. The major groups of agroforestry tree/shrub species integrated on smallholder farm plots were fruit trees, fuelwood trees/shrubs and trees/shrubs used as building materials. Results from Chi square statistic, Kruskal–Wallis test, and logistic regression analysis (p < 0.05) revealed that agroforestry practices especially home gardens with animals, home gardens, trees on grazing lands, and coffee-based agroforestry played a significant positive role in enhancing smallholder farmers’ resilience to the impacts of climate variability and change. The study therefore recommends that agroforestry be prioritized in national and international policy formulations owing to its ability to enhance smallholder farmers’ resilience faced with a fast changing climate.

English

This study contributes to the knowledge of the variants of coffee-based agroforestry systems (CAFS) of the semi-deciduous forest zone of Togo. To achieve this, forest, floristic and ecological data were collected in 163 random plots of 25 m &times; 25 m (625 m&sup2;), to analyze the typology of the CAFS and their characteristics across the study area. In the 10.1875 ha surveyed, results showed a total of 2510 stems of woody plants belonging to 138 species and 38 families. The average tree density was 246.38 trees/ha, whereas the basal area was 27.99 m&sup2;/ha. Four types of CAFS have been identified; the first type (G1) is the plant communities dominated by Milicia excelsa and Persa americana associated with coffee trees; the second type (G2) is characterized by CAFS with Albizia spp. and Citrus sinensis as dominant woody species; the third group (G3) is composed of communities dominated by Albizia adianthifolia and Milicia excelsa and the fourth group (G4) consists of CAFS dominated by M. excelsa and Antiaris africana. The floristic composition showed that the latter CAFS (G4) dominated by M. excelsa and A. africana was the most diversified, more rich in term of species (Species richness = 110, Shannon index = 4.06) and of which the basal area (Basal area = 34.32 m2/ha) is larger than the others. &nbsp; Key words: Coffee-based agroforest system, typology, semi-deciduous forest zone, Togo.

Kemampuan Agroforestri Berbasis Kopi (Coffea arabica) dalam Menyimpan Cadangan Karbon

Each type of forest ecosystem and the species in it have different abilities to absorb CO2 and produce biomass. Coffee-based agroforestry is thought to be able to increase the ability of forests to store carbon as a result of increasing species composition and density of plants in these forest areas. This study aims to determine the composition of plants and carbon stocks stored in coffee-based agroforestry forests in LMDH Paniis RPH Rancakalong BKPH East Manglayang KPH Sumedang Perum Perhutani Regional Division West Java and Banten. This study uses survey and laboratory methods. Data collection is done by collecting data directly at the research location, which is in the agroforestry forest area and natural forest area (as a comparison). Data obtained through observations in the field and laboratory are in the form of tree names, wood density, tree biomass and carbon stocks from biomass. The result shows that the agroforestry forest composition at LMDH Paniis RPH Rancakalong BKPH East Manglayang KPH Sumedang within 17,14 ha consists of Pine (Pinus mercusii), Big-leaf Mahogany (Swietenia macrophylla), Clove (Syzygium aromaticum) dan Coffee (Coffea arabica). The carbon stock is 1.869,73 kg/ha in agroforestry forest, 2.618,32 kg/ha in primary natural forest, and 1.460,91 kg/ha in secondary natural forest. Agroforestry forest has more carbon stock than the secondary natural forest, but agroforestry forest has less carbon stock than primary natural forest.

THE ABILITY OF COFFEE AGROFORESTRY SYSTEM TO STORE CARBON STOCK

Each type of forest ecosystem and the species in it have different abilities to absorb CO2 and produce biomass. Coffee-based agroforestry is thought to be able to increase the ability of forests to store carbon as a result of increasing species composition and density of plants in these forest areas. This study aims to determine the composition of plants and carbon stocks stored in coffee-based agroforestry forests in LMDH Paniis RPH Rancakalong BKPH East Manglayang KPH Sumedang Perum Perhutani Regional Division West Java and Banten. This study uses survey and experiment methods. Data obtained through observations in the field and laboratory are in the form of tree names, wood density, tree biomass and carbon stocks from biomass. The result shows that the agroforestry forest composition at LMDH Paniis RPH Rancakalong BKPH East Manglayang KPH Sumedang within 17,14 ha consists of Pine (Pinus mercusii), Big-leaf Mahogany (Swietenia macrophylla), Clove (Syzygium aromaticum) dan Coffee (Coffea arabica). The carbon stock is 1.869,73 kg/ha in agroforestry forest, 2.618,32 kg/ha in primary natural forest, and 1.460,91 kg/ha in secondary natural forest. Agroforestry forest has more carbon stock than secondary natural forest does and agroforestry forest has less carbon stock than the primary natural forest

Analisis Respon Hidrologi dan Kualitas Air DAS Cisangkuy

DAS Cisangkuy memiliki peran penting sebagai penyangga lingkungan dan pemasok air untuk Kota Bandung dan Kabupaten Bandung. Kuantitas dan kualitas air sungai perlu dipertahankan untuk memenuhi kebutuhan air. Penelitian ini bertujuan untuk menganalisis kinerja model SWAT untuk memprediksi respon hidrologi dan kualitas air DAS Cisangkuy dan untuk menganalisis respon hidrologi dan kualitas air dari skenario pengelolaan penggunaan lahan yang tersirat. Metode yang digunakan adalah permodelan dengan model hidrologi SWAT. Hasil penelitian menunjukkan bahwa model tersebut dapat digunakan untuk memprediksi respon hidrologi DAS Cisangkuy dengan nilai kalibrasi NSE sebesar 0.38 (memuaskan) dan nilai validasi NSE sebesar 0.43 (memuaskan). Pembentukan kawasan hutan lindung, Desain Teknis Rehabilitasi Lahan dan Hutan (RTk-RHL) dan skenario agroforestri berbasis kopi menunjukkan penurunan aliran permukaan, peningkatan aliran lateral dan aliran dasar. Respons hidrologi skenario RTRW menunjukkan peningkatan aliran permukaan dan penurunan aliran lateral dan aliran basa. Penurunan tertinggi konten N-organik, NO3, NH4, dan NO2 ditunjukkan oleh implikasi skenario RTRW.

English

The objective of this study was to assess farmers&rsquo; perception regarding the activities which degrade the soil and watershed and to analyze soil nutrients status under different agroforestry systems. The aim of the study was to identify and promote locally-known agroforestry-based practices for soil and watershed conservation in the savannah highland area of Cameroon. Semi-structured questionnaires were administered to 120 farmers purposively selected from 10 villages in the Ako sub division characterized by favorable environmental conditions for agricultural production and the presence of agroforestry systems. The 10 villages were classified following a stratified sampling based on the degree of degradation of the soil and the watershed. Ako sub division was chosen because it is a priority zone for agricultural production and some of the practices are unsustainable leading to soil and watershed degradation. Soil samples were collected from each of the agroforestry systems found in the villages sampled and were analyze for soil nutrients status. The soil nutrients that were analyzed are: Organic matter by the wet oxidation method; exchangeable cations; cation exchange capacity; total nitrogen by Kjedahl method; available phosphorus by Bray II method and carbon to nitrogen ratio. The results showed that farmers perceived poor farming methods (33.10%) and deforestation (29.58%) as the main activities degrading the soil and the watershed. The standard values developed were used to compare the level of soil nutrients in each agroforestry system. The results of the soil analysis under each agroforestry system in Ako indicated that, soils were highly deficient in phosphorus in all the systems. The values were very low in all the systems ranging from 0.21 in palm agroforestry system to 0.46 in cocoa agroforestry system. Based on the level of organic matter and cation exchange capacity observed in the different farms, the agroforestry systems that should be promoted are: Coffee agroforestry systems, and cocoa agroforestry systems. Key words: Cocoa and coffee-based agroforestry systems, soil properties, watershed, farmers&rsquo; opinion. &nbsp

VERTICAL DISTRIBUTION AND SPATIAL PATTERN OF FINE ROOT DENSITY IN COFFEE – BASED AGROFORESTRY SYSTEMS UNDER ORGANIC AND CONVENTIONAL INPUTS

&lt;p&gt;This research shows results on spatial changes of fine roots (&lt;em&gt;d&lt;/em&gt; &amp;lt; 2.0 mm) in two &lt;em&gt;Coffea arabica&lt;/em&gt;- shade tree associations: coffee shaded by a) &lt;em&gt;Abarema idiopoda &lt;/em&gt;(timber and nitrogen fixing tree), and b) &lt;em&gt;Terminalia amazonia &lt;/em&gt;(timber tree). These associations were submitted to organic and conventional inputs. In order to identify fine root vertical distribution and using soil cores, coffee and shade tree fine roots were quantified to 50 cm depth. A geostatistical approach was used to quantify the scale of spatial heterogeneity (aggregation patterns) of coffee and shade- tree fine root length density (RLD, cm cm&lt;sup&gt;-3&lt;/sup&gt;; 0- 20 cm soil depth). Results about vertical distribution demonstrated that in all the associations the coffee fine roots were concentrated in the upper 20 cm of soil&lt;em&gt;. &lt;/em&gt;The significant amount of coffee fine roots in the litter layer demonstrated the importance of including this layer for a real estimation of coffee fine roots in shaded coffee systems. The shade tree fine roots showed marked differences in their vertical distribution and affected the fine root density of coffee plants between 0- 50 cm soil depth; being more abundant when coffee is planted with &lt;em&gt;T. amazonia&lt;/em&gt;. The scale of spatial heterogeneity (aggregation patterns) for coffee RLD was longer in the organic plot than in the conventional plot for all of the coffee- tree associations. In the coffee- &lt;em&gt;T. amazonia&lt;/em&gt; association, the semivariogram of the coffee RLD under conventional management showed a spatial correlation at a relative short scale (3.5 m); however, in the organic plot, the semivariogram did not show spatial heterogeneity and exhibited a random pattern of coffee RLD at the scale examined. It is concluded that the type of management affects the pattern of spatial aggregation (spatial heterogeneity scale) of &lt;em&gt;C. arabica&lt;/em&gt; fine roots. Implying that the ability of coffee roots for the water and nutrient intake change spatially, either vertically or horizontally, depending on the accompanying shade- tree. According to the occupation of the fine roots within the layers of the soil to the depth studied, &lt;em&gt;T. amazonia&lt;/em&gt; seems to be the timber species recommended for the establishment of a coffee-based agroforestry system.&lt;/p&gt;

Soil Organic Carbon and Nitrogen Stocks Following Land Use Changes in a Sub-Humid Climate

There has been an incessant conversion of natural forests to agricultural land uses such as farmlands, grasslands and parkland agro-forestry in Africa during the last century. This study investigated changes in soil organic carbon (SOC) and total nitrogen (TN) stocks following the conversion of a natural forest to coffee-based agro-forestry, grazing grassland and well-managed maize farm in a sub-humid tropical climate of Ethiopia. Soil samples (up to 1m depth) were taken from each of these four land use types. Taking the natural forest as a baseline and with duration of 35 years since land use conversion, the total SOC and TN stocks were not significantly different (P &gt; 0.05) among the different land use types when the entire 1m soil depth was considered. However, in the upper 0-10cm soil depth, the SOC and TN stocks were significantly higher (P &lt; 0.05) in the natural forest than the agricultural land use types. There were different patterns of SOC and TN distributions along the soil depths for the different land use types. The SOC stocks decreased with depth in natural forest, but did not show any increasing or decreasing trends in maize farm, grazing grassland, and coffee-based agroforestry. The results of this study revealed that the negative effects of converting natural forests to agricultural land use types on SOC and TN can be prevented through appropriate land management practices in cultivated and grazing lands and use of proper agroforestry practices in a sub-humid tropical climate.

Smallholders’ avocado production systems and tree productivity in the southern highlands of Ethiopia

Ethiopia is one of the top five avocado producers in sub-Saharan Africa. Despite increasing recognition for its nutritional value and economic importance, information on smallholder avocado production systems across agro-climatic zones and determinants for tree productivity are literally lacking. Therefore, the objectives of this study were to examine the determinants for avocado tree holdings by smallholder farmers and investigate the effect of avocado production systems and management conditions on fruit yield by individual avocado trees in Southern Ethiopia. Data required for the study was collected through a combination of focus group discussions, household survey and field tree inventories. The data was analyzed using descriptive statistics, analyses of variance and linear regression methods using statistical software for social sciences (SPSS version 20). In the study region, avocado is mainly grown as an integral component of the coffee- and enset-based agroforestry systems. The number of avocado trees owned by smallholder producers was related to district, sex of household head, age of household head, educational status, land holding size, pest and disease damage and access to extension services. Productivity of avocado was significantly (p < 0.05) different between production systems. The highest avocado fruit yield was observed from trees grown in the coffee and enset-based agroforestry systems. However, the smallholder producers complain that the yields of coffee and enset grown under avocado trees could be very low. The total height of avocado trees was significantly (p < 0.05) different across the different production systems. The mean heights of matured (21–25 years old) avocado trees were 17.57 ± 0.86 m (±SE; N = 20) under coffee-based agroforestry system and 14.93 ± 1.24 m when grown as individual trees around homes. Proper extension support is needed to disseminate improved production techniques: encompassing proper tree spacing, tree training, pruning, soil amendments, growing optimum number of trees for successful pollination and improved harvesting.

Management Effects on Woody Species Diversity and Vegetation Structure of Coffee-based Agroforestry Systems in Ethiopia

The effect of Ethiopian coffee production systems on the diversity and composition of woody species and vegetation structure was studied along a management gradient ranging from low to intensive, namely forest coffee, semi-forest coffee, semi-plantation coffee and plantation coffee. Data were obtained from a field survey and secondary sources. A reduction of species diversity and a shift in species composition were found over the range of low, moderate to intensive management systems, together with dominance of a few pioneer tree species in the two most intensively cultivated systems. There was also a structural variation along the management gradient and within semi-forest coffee though not consistent over variables and sites. The dominance of pioneer species can serve as an indicator of ecological status (e.g. a loss of species or a reduction of refuges for forest dwelling organisms) and productivity of such systems because long-term coffee productions and resilience against disturbances (e.g. climate change) can be negatively affected by management intensity.

Arbuscular mycorrhizal fungi associated with shade trees and Coffea arabica L. in a coffee-based agroforestry system in Bonga, Southwestern Ethiopia

In a first step to understand the interactions between Coffea arabica L. trees and mycorrhizae in Ethiopia, an investigation of the current mycorrhizal colonization status of roots was undertaken. We sampled 14 shade tree species occurring in coffee populations in Bonga forest, Ethiopia. Milletia ferruginea, Scheffiera abyssinica, Croton macrostachyus, Ficus vasta, F. sur, Albizia gummifera, Olea capensis, Cordia africana, Ehretia abyssinica, Pouteria adolfi-friederici, Pavetta oliveriana, Prunus africana, Phoenix reclinata and Polyscias fulva. Coffee trees sampled under each shade tree were all shown to be colonized by arbuscular mycorrhizal fungi (AM fungi). Four genera and 9 different species of AM fungi were found in the soils. Glomus (Sp1, Sp2, &amp; Sp3 &amp; Sp4), Scutellospora (Sp1 &amp; Sp2) and Gigaspora (Sp1 &amp; Sp2) were found under all 14 shade tree species, whereas Acaulospora (Sp1) occurred only in slightly acidic soils, within a pH range of 4.93-5.75. Generally, roots of the coffee trees were colonized by arbuscules to a greater degree than those of their shade trees, the arbuscular colonization percentage (AC%) of the former being higher than the latter (signifIcant difference at 0.05 level). Though differences were not statistically signifIcant, the overall hyphal colonization percentage (HC%) and mycorrhizal hyphal colonization percentage (MHC%) were shown to be slightly higher under coffee trees than under their shade trees. However, the differences were statistically significant at 0.05 level in the case of HC% values of coffee trees under Pouteria adolf-friederici and MHC% under Cordia africana. Spore density and all types of proportional root colonization parameters (HC%, MHC%, AC% and vesicular colonization percentage, VC%) for both coffee and shade trees were negatively and significantly correlated with organic soil carbon, total N, available P, EC and Zn. Correlation between arbuscular colonization for coffee (AC%) and organic carbon was not significantly positive at a 0.05 level. Incidence of specific spore morphotypes was also correlated with physical and chemical soil properties. Results indicate that AM fungi could potentially be important in aforestation and help to promote coffee production activities in Ethiopia providing an alternative to expensive chemical fertilizer use, and would offer management methods that take advantage of natural systems dynamics that could potentially preserve and enhance coffee production. Key words: aforestation; agroforestry, coffee groves, ecology, integrated production systems, rhizosphere, sustainable agriculture, symbiosis