Coffee Plots Research Articles

Influence of plot features and landscape structure on the epidemics of coffee berry disease (Colletotrichum kahawae Waller & Bridge) in southwest Ethiopia

Coffee berry disease (CBD), caused by Colletotrichum kahawae, is a major fungal disease of coffee in east Africa, and particularly in Ethiopia. To assess the influence of plot features (elevation and slope) and landscape structure (land use types) on the epidemics of CBD, a study was conducted in 2012 and 2013 in 30 smallholders’ coffee plots in southwest Ethiopia. Elevation was the most determining plot feature that influenced the incidence of CBD and berry drops. North-facing coffee plots were affected more by CBD compared to south-facing plots. Landscape structure generally had weak relationship with CBD incidence and berry drops. Overall, coffee growers should give more attention to plot features than landscape structure for CBD management.

Coffee agroforestry systems capable of reducing disease-induced yield and economic losses while providing multiple ecosystem services

Crop losses caused by pests and diseases decrease the incomes and threaten the livelihoods of thousands of families worldwide. A good example of the magnitude of these impacts are the massive crop losses experienced by coffee farmers in Central America due to coffee leaf rust. Coffee farmers need agroecosystems that are capable of regulating the negative impacts of pests and diseases while providing other ecosystem services on which their households and society depend. In this study, we aimed to identify the most promising coffee agroforestry systems for regulating diseases and ensuring the provision of other ecosystem services. During two years, in a research network of 61 coffee plots under a wide variety of shade and management conditions in Turrialba, Costa Rica, we quantified primary and secondary coffee losses (yield and economic losses) and indicators of three other ecosystem services: provisioning of agroforestry products (bananas, plantains, other fruits, and timber), maintenance of soil fertility and carbon sequestration. We then performed an analysis of the relationships between losses and ecosystem service indicators. Based on the results of relationships and on three criteria, we identified the coffee agroforestry systems that had the lowest losses due to diseases and that provided desirable levels of agroforestry products, soil fertility and carbon sequestration. We found multiple significant relationships between losses and ecosystem services (including both tradeoffs and synergies) which allowed us to derive recommendations for better management strategies to reduce yield losses. We identified six coffee agroforestry systems (CAFs) as the most promising ones for reducing losses while simultaneously providing other ecosystem services. One of these CAFs was a simple agroforestry system (dominated by service trees), three were medium diversified CAFs and two were highly diversified CAFs (systems including service trees, timber trees, fruit trees and musaceas). The six CAFS differed in their cropping practices and farmer profitability objectives. The six CAFs offer several options for the design of new coffee plantations or for the transformation of existing plantations. Several of this promising CAFs use little fungicides, which is an indicator that the reduction of chemical inputs could be possible. Our results suggest that the regulation of diseases and associated losses in agroforestry systems should be based on, and take advantage of, the positive effects of plant biodiversity, adequate shade cover, good soil fertility, and minimal use of fungicides.

Intercropping of Coffee with Enset (<i>Enset ventricosum</i> Welw. Cheesman) at Teppi, Southwestern Ethiopia

Intercropping is an excellent system of cropping which achieves a diversified and intensified crop production through better utilization of growth resources and inputs. An experiment was conducted at Teppi Agricultural Research Center from 2011 to 2015 cropping calendar to determine optimum intercropping ratios of coffee and enset that enhances yield productivity and land-use efficiency. The study consisted of six treatments viz., sole cropping of each crop, a staggered planting of both crops, 1:1, 2:1, 3:1 row ratios of coffee to enset, respectively. The experiment was laid out in a randomized complete block design with three replications. A lowland coffee variety (Catimor J-19) and local enset variety were used. The result revealed that the growth parameters of both coffee and enset were not significantly influenced by intercropping, except the internode length of coffee primary branches. However, the yields of the component crops were significantly (p<0.05) affected by different ratios of intercropping. The maximum clean coffee yield was obtained from the sole coffee plot (1127.68 kg ha^-1) followed by the staggered plot (1082.04 kg ha^-1). Similarly, the highest kocho (44167 kg ha^-1) and bulla (1734.70 kg ha^-1) yields were also found from the sole enset plot. On the other hand, the combined yields of the component crops in all intercropped plots were higher than the sole plots and the LER value was greater than 1. The maximum relative yield advantage of coffee and LER value was recorded from the staggered plot followed by the plot consists of a 3:1 row ratio of coffee to enset. In general, the result was disclosed the agronomic feasibilities of coffee and enset intercropping and the compatibility of the component crops as well. Therefore, it can be concluded that staggered planting of coffee and enset is a suitable cropping arrangement for enhancing the yield productivity of the component crops and ensuring food security for the resource-poor farmers. Thus, the aforementioned planting arrangement can be recommended for farmers and growers in the study area. Nevertheless, additional researches are required in different agro-ecologies of the country with economic feasibility studies to deliver a concrete recommendation.

Intercropping Coffee (&amp;lt;i&amp;gt;Coffea arabica&amp;lt;/i&amp;gt;) and Korarima (&amp;lt;i&amp;gt;Aframomum corrorima&amp;lt;/i&amp;gt; (Braun) P.C.M. Jansen) at Tepi, Southwest Ethiopia

A field experiment was conducted at Tepi, southwest Ethiopia, from 2013 – 2017, to determine optimum plant population yield of component crops and land productivity in the coffee/korarima intercropping system. Test crops were Catimore-J21 variety for coffee and a local variety of korarima. The experiment consisted of five treatments arranged in a Randomized Complete Block Design with three replications. Data collected were statistically analyzed using SAS computer software. The productivity of the system was evaluated using a land equivalent ratio. Results showed that the coffee yield was significantly (p<0.05) influenced by intercropping, while the growth of the coffee tree did not significantly affect by intercropping. Whereas, the growth and yield of korarima plants were significantly (p<0.05) influenced by intercropping except for plant height, length, and girth of fruit capsule. Accordingly, the higher coffee yield advantages were found from sole plots when compared with intercropped coffee plots and followed by 2 to 1 coffee and korarima intercropping ratio. Similarly, the advanced yield of korarima was recorded from sole stands followed by 1 to 2 coffee and korarima intercropping ratio. The maximum land equivalent ratio was recorded at a planting pattern of 2 to 1 coffee and korarima intercropping ratio as compared to other treatments. Therefore, it could be concluded that intercropping of coffee with korarima is biologically and agronomically feasible, and the aforementioned treatment could be recommended for the study area. However, it is important to advise farmers in the area and similar agro-ecology to supplement irrigation water to the field especially during the dry spell period.

Coffee, Migration and Climatic Changes: Challenging Adaptation Dichotomic Narratives in a Transborder Region

The narratives of migration as adaptation and in situ adaptation are well established in mainstream adaptation policy and are usually presented as independent and opposing trends of action. A common and fundamental element of such narratives is the depoliticized conception of both migration and adaptation. Using a trans-scalar approach, we address the migration–coffee–climate change nexus: first at a regional scale, at the conflictive border of Guatemala–Mexico, to show the contradiction between the current Central American migratory crisis and the narrative of migration as adaptation; second, at a local scale and from an ethnographic perspective, we focus on the process of in situ adaptation in shade-grown coffee plots of smallholder coffee farmers in the Tacaná Volcano cross-border region, between Chiapas and Guatemala. We argue that the dichotomy “in situ adaptation” versus “migration as adaptation” is not useful to capture the intertwined and political nature of both narratives, as illustrated in the case of the renovation of smallholders’ coffee plots in a context of climatic changes. We provide elements to contribute towards the repolitization of adaptation from an integral perspective.

Relationship Between Spatio-Temporal Leaf Area Index and Crop Coefficient When Monitoring Coffee Plots in Brazil Using the Sentine-2

Robust monitoring techniques for perennial crops have become increasingly possible due to technological advances in the area of Remote Sensing (RS), and the products are available through the European Space Agency (ESA) initiative. RS data provides valuable opportunities for detailed assessments of crop conditions at plot level using high spatial, spectral, and temporal resolution. This study addresses the monitoring of coffee at the plot level using RS, analyzing the relationship between the spatio-temporal variability of the Leaf Area Index (LAI) and the crop coefficient (Kc); the Kc being a biophysical variable that integrates the potential hydrological characteristics of an agroecosystem compared to the reference crop. Daily and one-year Kc were estimated using the relation of crop evapotranspiration and reference. ESA Sentinel-2 images were pre-analyzed and atmospherically corrected, and Top-of-the-Atmosphere (TOA) reflections converted to Top-of-the-Canopy (TOC) reflectance. The TOCs resampled at the 10m resolution, and with the angles corresponding to the directional information at the time of the acquisition, the LAI was estimated using the trained neural network available in the Sentinel Application Platform (SNAP). During 75% of the monitored days, Kc ranged between 1.2 and 1.3 and, the LAI analyzed showed high spatial and temporal variability at the plot level. Based on the relationship between the biophysical variables, the LAI variable can substitute the Kc and be used to monitor the water conditions at the production area as well as analyze spatial variability inside that area. Sentinel-2 products could be more useful in monitoring coffee in the farm production area.

Landscape context and plot features influence the epidemics of coffee leaf rust (Hemileia vastatrix) in southwest Ethiopia

From 2013 to 2015, a study was conducted on 29 coffee plots to assess the influence of landscape context and plot features on the epidemics of coffee leaf rust (CLR) descriptors in Gumay and Setema districts, Southwest Ethiopia. Maximum CLR severity and number of sporulating lesion density per leaf was significantly correlated with different land use types (tree density at 100 m, 200 m, pasture and crop lands at 200 m circular radius), and plot features (altitude, North-South aspect, East-West aspect and leaf area index) over different years of observation. High tree density in the surrounding coffee plots significantly increased the severity of the disease. There was a general decreasing trend of CLR severity, sporulating lesion density and proportion of leaf fall over the altitudinal gradient. The interaction of landscape context with CLR descriptors found were so complex and need further detail analysis.

COFFEE LEAF MINER INCIDENCE AND ITS PREDATION BY WASP IN COFFEE INTERCROPPED WITH RUBBER TREES

The coffee leaf miner (CLM) Leucoptera coffeella has a wide distribution and causes significant losses in coffee plantations ( Coffea spp. ) in Brazil. Its occurrence can be mitigated in intercropped systems, with the rubber tree ( Hevea brasiliensis ) adapting well to the consortium, while also providing extra income to the producer. We aimed to determine whether the afforestation influences the microclimate and affects the leaf miner incidence and its predation by wasp in coffee plants intercropped with rubber trees. The study was undertaken in state of Parana, Brazil, using coffee plants intercropped with rubber trees planted in double rows (alleys) spaced at 13, 16 and 22 m between alleys, and compared to sole cropping coffee plots. From January 2008 to November 2010, the presence of CLM’s lesions including those with signs of wasp predation was monitored in coffee plants intercropped with rubber trees and in the non-consorted coffee. A higher CLM’s incidence was verified in monoculture coffee plots, while coffee plants located under and two meters away from rubber trees had the lowest incidences. CLM’s incidence in intercropping system got higher as it increased distance from the trees. The number of lesions with signs of predation by wasps was positively correlated with the number CLM’s lesions, indicating a density-dependent predator-prey relationship. The coffee plants intercropped with alley rubber trees reduce the CLM’s occurrence and can be a management’s tactic for this economically important pest.

Three Species of Weeds Enhance The Population of Predator and Parasitoid of Coffee Berry Borers

Flowering weeds can serve as refugia for natural enemies. In coffee plantation, they might has the potential to attract predator and parasitoid of Coffee Berry Borer (CBB), Hypothenemus hampei Ferr. (Coleoptera: Scolytidae). The aim of this research was to elucidate the influence of weeds to the presence of predator dan parasitoid and their impact to the population of CBB. The research was conducted at Ngantang, Malang Regency and in Laboratory of Pest, Faculty of Agriculture, Brawijaya University. Three types of weed used were: Ageratum conyzoides L. (Asteraceae), Synedrela nodiflora(L.) Gaertn. (Asteraceae), and Arachis pintoi Krap. &amp; Greg. (Fabaceae). The research consisted of two experiments (1) coffee plot with single species of weed and (2) coffee plot with two species of weeds. The results of experiment I and II showed that A. conyzoides, S. nodiflora, A. pintoi and its combination in coffee plantation significantly attracted the predator and parasitoid of CBB. The population of CBB was not significantly different between coffee plot with and without weed. The existence of A. conyzoides, S. nodiflora and A. pintoi in coffee plantations could increase the number of predator and parasitoid of CBB around coffee tree. This result showed that the presence of weeds in coffee plantation is an important factor in maintaining the predators and parasitoid of CBB population.

Local and regional drivers of the African coffee white stem borer (Monochamus leuconotus) in Uganda

AbstractThe African coffee white stem borer (CWSB) Monochamus leuconotus is a destructive pest of Arabica coffee in Africa. Documentation on outbreaks, spatiotemporal development and the relationship with different environmental conditions and coffee production system is limited. To underpin effective control measures, we studied aspects of local and regional pest drivers in Eastern Uganda. At the local scale, we (i) characterized the temporal development of CWSB and explored associations with environmental and shade‐related indicators. During two growing seasons and on 84 coffee plots, we recorded CWSB incidence/infestation and microclimate on an altitudinal gradient and different shading systems. The bimodal rainfall, altitude and shade affected CWSB development through their effect on minimum temperature. At the landscape level, we (ii) analyzed the spatial pattern of CWSB. Data on CWSB were collected on 180 plots. Pest incidence showed a spatial arrangement varying by districts. A possible relationship with human movement and the landscape context contributing to pest spread is suggested. CWSB control measures should be synchronized with the bimodal rainfall patterns and an emphasis should be given to identifying and limiting pathways of pest spread from highly infested to new areas.

Multi-scale measurements show limited soil greenhouse gas emissions in Kenyan smallholder coffee-dairy systems

Efforts have been made in recent years to improve knowledge about soil greenhouse gas (GHG) fluxes from sub-Saharan Africa. However, data on soil GHG emissions from smallholder coffee-dairy systems have not hitherto been measured experimentally. This study aimed to quantify soil GHG emissions at different spatial and temporal scales in smallholder coffee-dairy farms in Murang'a County, Central Kenya. GHG measurements were carried out for one year, comprising two cropping seasons, using vented static chambers and gas chromatography. Sixty rectangular frames were installed on two farms comprising the three main cropping systems found in the area: 1) coffee (Coffea arabica L.); 2) Napier grass (Pennisetum purpureum); and 3) maize intercropped with beans (Zea mays and Phaseolus vulgaris). Within these fields, chambers were allocated on fertilised and unfertilised locations to capture spatial variability. Cumulative annual fluxes in coffee plots ranged from 1 to 1.9kgN2O-Nha−1, 6.5 to 7.6MgCO2-Cha−1 and −3.4 to −2.2kgCH4-Cha−1, with 66% to 94% of annual GHG fluxes occurring during rainy seasons. Across the farm plots, coffee received most of the N inputs and had 56% to 89% higher emissions of N2O than Napier grass, maize and beans. Within farm plots, two to six times higher emissions were found in fertilised hotspots – around the perimeter of coffee trees or within planted maize rows – than in unfertilised locations between trees, rows and planting holes. Background and induced soil N2O emissions from fertiliser and manure applications in the three cropping systems were lower than hypothesized from previous studies and empirical models. This study supplements methods and underlying data for the quantification of GHG emissions at multiple spatial and temporal scales in tropical, smallholder farming systems. Advances towards overcoming the dearth of data will facilitate the understanding of synergies and tradeoffs of climate-smart approaches for low emissions development.

Influence of shaded systems on Xylosandrus compactus infestation in Robusta coffee along a rainfall gradient in Uganda

Abstract We investigated the relationship between characteristics of coffee shade systems and coffee pest infestation by the black coffee twig borer Xylosandrus compactus Eichhoff. The pest deprives Uganda of $40 millions annually, yet its control remains inadequate. The present study considered three rainfall zones in Central Uganda and 50 coffee plots that were randomly selected from each rainfall zone. Data were collected on X. compactus infestation and key shade indicators: canopy cover, tree‐species densities, diameter at breast height (DBH) and ratio of coffee to banana. Cluster analysis revealed two coffee shade systems: a matured shade tree (MST) system and a young poly‐culture (YPC) system. Xylosandrus compactus infestations were significantly less in the MST system than in the YPC system and significantly less in the low rainfall zone than in the high rainfall zone. An increase in the density of Carica papaya and Albizia chinensis significantly reduced and increased X. compactus infestation, respectively. A higher average DBH of individual trees and a higher density of trees that exude sap significantly lowered X. compactus infestation. Suppressing X. compactus infestation requires bigger trees, a high density of sap‐exuding trees and no Albizia chinensis. Further research should aim to investigate X. compactus flight activity and microclimate influencing X. compactus population dynamics.

Certification of Semi-forest Coffee as a Land-sharing Strategy in Ethiopia

We analyze whether private sustainability standards can improve the economic benefits from less intensified semi-forest coffee production in southwestern Ethiopia. We compare garden and semi-forest coffee systems, including non-certified and Rainforest Alliance certified semi-forest coffee, and evaluate yields, returns to land, returns to labor and profits. We use original household- and plot-level survey from 454 households and 758 coffee plots derived from a household survey and Geographic Information Systems, and ordinary least squares and fixed effects regression models. We find that more intensified garden coffee plots bring about higher yields and returns to land than less intensified semi-forest coffee plots; and that Rainforest Alliance certification of semi-forest coffee leads to higher returns to land and labor, and profits than non-certified semi-forest and garden coffee, mainly by guaranteeing farmers a better price and not by improving yields. Findings imply that in southwestern Ethiopia coffee certification can support farmers' incentives for land-sharing between coffee production and semi-natural forest conservation.

Automatic fruit count on coffee branches using computer vision

In this article, a non-destructive method is proposed to count the number of fruits on a coffee branch by using information from digital images of a single side of the branch and its growing fruits. In order to do this, 1018 coffee branches at different ripening stages. They had different numbers of fruits, harvest dates, were of different varieties, and were at different stages of coffee tree’s life. A Machine Vision System (MVS) was constructed, which was capable of counting and identifying harvestable and not harvestable fruits in a set of images corresponding to a specific coffee branch was constructed. This MVS consists of an image acquisition system, based on mobile devices (it does not require to control of the environmental conditions), and an image processing algorithm to classify and detect each one of the fruits in the acquired images. After obtaining information regarding the number of fruits identified by the MVS, linear estimation models were constructed between the detected fruits automatically and the ones observed on the coffee branch. These models were calculated for fruits in three categories: harvestable, not harvestable, and fruits whose maturation stage were disregarded. These models link the fruits that are counted automatically to the ones actually observed with an R2 higher than 0.93 one-to-one. Not only is the MVS used to estimate the number of fruits on the branch but also to estimate their maturation percentage and weight. The MVS was validated in four Variedad Castillo® coffee plots, in different stages of development and with different densities. We found that MVS neither overestimates nor underestimates the number of fruits and that it shows a correlation higher than 0.90 at early stages of crop development, when tree fruits are still not harvestable. The information obtained in this research will spawn a new generation of tools for coffee growers to use. It is an efficient, non-destructive, and low-cost method which offers useful information for them to plan agricultural work and obtain economic benefits from the correct administration of resources.

Estimation of Suitable Areas for Coffee Growth Using a GIS Approach and Multicriteria Evaluation in Regions with Scarce Data

Abstract.An estimate of appropriate areas for crop production is highly desirable in Ecuador and many other parts of the world for achieving optimum utilization of the available natural resources. Lack of knowledge on best methodologies of coffee management applicable to local conditions has contributed to the inefficient use of land area. This study aimed to develop maps of suitable areas for coffee production in Ecuador. The study was conducted over an area of 800 km2 approximately, where Geographic Information System (GIS) methodology proposed by the official government agency and Multi-criteria evaluation (MCE) was applied. Different parameters such as hydrology, climate, and crop information were considered. Maps were validated in the field with a biophysical characterization on the coffee plots. Also, four suitability classes were defined to describe coffee production: suitable, moderately suitable, marginally suitable, and not suitable areas. More than 50% of study area is suitable and moderately suitable for coffee crop production with the two analyzes (GIS and MCE). The main constraints to increasing coffee production are poor soil depth and fertility, and rainfall amount received needs to be supplemented by irrigation. According to statistical validation both methodologies exposed in this study can be useful for other regions with scarce data to properly manage the territory. Keywords: Biophysical characterization, Coffee production area, Ecuador, GIS, Scarce data, Multi-criteria evaluation.

Crecimiento, acumulación de biomasa seca y nutrientes en los frutos de café (Coffea arabica L.) variedad Pacas, Masatepe, Nicaragua

De abril a diciembre de 2012, en un ensayo ya establecido se realizó un estudio en el cultivo de café variedad pacas, con el objetivo de determinar las curvas de crecimiento, acumulación de biomasa seca y acumulación de nutrientes (N, P, K, Ca y Mg) en los frutos de café uva. El ensayo fue establecido en el año 2000 en el Jardín Botánico hoy conocido como Centro Nacional de Educación y Cooperativismo (CENECCOP), Masatepe, Nicaragua. Se seleccionaron cuatro parcelas grandes con combinación de árboles de sombra maderables y de servicio y una parcela a pleno sol. Los tratamientos en estudio fueron a) Inga laurina y Simaruba glauca, b) Samanea saman y Tabebuia rosea, c) Samanea saman e Inga laurina, d) Tabebuia rosea y Simaruba glauca y e) una parcela a pleno sol. Las parcelas fueron distribuidas en un diseño de bloques completos al Azar (BCA). Las variables evaluadas en los frutos de café fueron diámetro polar, diámetro ecuatorial y peso seco. Los frutos se secaron en el horno a 70 °C y posteriormente se utilizó un molino Foss Tecator Cyclotec para obtener una muestra fina. De la muestra molida de los frutos, en el laboratorio de suelo y agua de la UNA se determinaron las concentraciones de N, P, K, Ca y Mg. Los datos fueron colectados cada 30 días. Para el análisis estadístico se utilizó SAS 9.1. Las curvas de crecimiento del fruto y la acumulación de peso seco se ajustaron a regresiones no lineales simples y dobles exponenciales. Se realizó una correlación entre el diámetro polar y diámetro ecuatorial de los frutos dando un coeficiente de determinación r de 98% (Pr&gt;F= 0.0001). Para el ajuste de la curva de aumento de peso seco se utilizó el modelo Probit normal. El mayor crecimiento de los frutos se dio durante los primeros 90 días y la mayor acumulación de nutrientes se dio entre los 90 y 210 días. La combinación de árboles leguminosos presentó el diámetro polar y ecuatorial más alto. También la acumulación de biomasa seca fue mayor en el tratamiento con sombra de leguminosas.Revista Científica Vol. 15. Nº 24, p. 6-12 mayo 2015

The Adoption of Sustainable Management Practices by Mexican Coffee Producers

&lt;p&gt;In order to maintain optimal growing conditions on coffee plots, producers in Mexico are encouraged to renovate their stock of coffee trees, use fertilizer, implement soil conservation measures and manage shade levels. The adoption of these sustainable management practices (SMPs) by smallholder coffee growers has become an important rural development objective, especially as a way to overcome low yields, poverty and land degradation. However, adoption rates for SMPs remain below expected levels, a situation that potentially threatens the long- term viability of the coffee sector in Mexico. To better understand the choices made by producers, a multivariate probit technique was used which modelled the adoption of possibly interrelated SMPs using data from a survey of 119 coffee producers. The analysis reveals that adoption of SMPs is related to the size of coffee holdings, the socio-economic characteristics of producers and the role of social capital, the latter being a key factor in the overall adoption process. Surprisingly, government subsidies to coffee growers were not tied to higher adoption rates, suggesting the need for policy reforms in order to better facilitate the uptake of new practices. The results indicate that efforts aimed at strengthening local institutions and organizing coffee growers into producer associations could increase the adoption of SMPs in smallholder coffee systems.&lt;/p&gt;

Humification degree and its relationship with some soil physical characteristics on robusta coffee (Coffea canephora) plantation

Soil moisture stress in coffee plant impacts on the productivity of coffee fruit at PT. Perkebunan Nusantara XII, it is because the low ability of the soil to store water. The ability of the soil to store water can be increased by increasing the organic matter content of soil, especially humic substances. Soil organic matter plays an important role in the improvement of soil physical properties, especially the availability of soil moisture for plants. The purpose of this study was to analyze several humification parameters at four age of plantations plots of coffee and its relation to the water distribution potensial on Inceptisol PT. Perkebunan Nusantara XII Malang district. The research was conducted at PT. Perkebunan Nusantara XII were taken soil samples from 8, 28, 40, and 80 years old robusta coffee plots at 0-30 cm and 30-60 cm soil depth. The results showed that the increasing the age of the coffee plantations significantly increased the input of organic matter in the soil, with indicators of increased litter on soil surface, increased levels of soil C-organic and N-total, humic acid and soil pH. Increasing age of coffee plantations until 80 years did not affect to the value of humification parameters (C/N ratio, HA/FA ratio, E4/E6 ratio, and the humification rate (HR)). The age of coffee plantations affected the total acidity, carboxylic groups and phenolic OH, where the values tended to decrease with the older of coffee plantations in the 0-30 cm of soil layers and increased in 30-60 cm. Increasing age of coffee plantations improved the total pores and available water content in the 0-30 cm of soil layer.

LOCAL KNOWLEDGE OF TREE ATTRIBUTES UNDERPINS SPECIES SELECTION ON COFFEE FARMS

SUMMARYThe extent to which coffee agroforestry systems provide ecosystem services depends on local context and management practices. There is a paucity of information about how and why farmers manage their coffee farms in the way that they do and the local knowledge that underpins this. The present research documents local agro-ecological knowledge from a coffee growing region within the vicinity of the Aberdare Forest Reserve in Central Kenya. Knowledge was acquired from over 60 coffee farmers in a purposive sample, using a knowledge-based systems approach, and tested with a stratified random sample of 125 farmers using an attribute ranking survey. Farmers had varying degrees of explanatory knowledge about how trees affected provisioning and regulating ecosystem services. Trees were described as suitable or unsuitable for growing with coffee according to tree attributes such as crown density and spread, root depth and spread, growth rate and their economic benefit. Farmers were concerned that too high a level of shade and competition for water and nutrients would decrease coffee yields, but they were also interested in diversifying production from their coffee farms to include fruits, timber, firewood and other tree products as a response to fluctuating coffee prices. A range of trees were maintained in coffee plots and along their boundaries but most were at very low abundances. Promoting tree diversity rather than focussing on one or two high value exotic species represents a change of approach for extension systems, the coffee industry and farmers alike, but is important if the coffee dominated landscapes of the region are to retain their tree species richness and the resilience this confers.

Delicate balance between pest and disease injuries, yield performance, and other ecosystem services in the complex coffee-based systems of Costa Rica

Pests and diseases are the main yield-reducing factors in simplified agricultural systems. Their role in complex, diverse, agricultural systems may, however, be less apparent because of the many interactions in which they are involved. However, it is essential to understand the relationships between pests and diseases, on the one hand, and ecosystem services (including crop production), on the other, to develop sustainable agroecosystems.Our study aims to illustrate these complex relationships based on the example of coffee agroecosystems in Costa Rica. We analysed a dataset consisting of 107 coffee plots characterized for their topoclimates, soils, coffee plant production characteristics, cropping practices, and pest and disease injuries. Meta-variables were created through cluster analyses to account for these different broad attributes of coffee-based agroecosystems. In particular, coffee injury profiles were determined on the basis of injury levels incurred by pathogens, nematodes, and insects over the course of one growing season. We used correspondence analysis to assess the levels of linkage between injury profiles and other agroecosystem meta-variables. Indicators of biodiversity based on shade diversity and of attainable yield were incorporated in the analysis as additional variables. Four groups of coffee-based agrosystems were identified, ranging from extensive (low-input, perennial polyculture) to intensive (unshaded high-input monoculture). Each group of coffee-based agroecosystem corresponds to varying levels of pest and disease injuries, crop yield, and ecosystem service provision, excluding coffee production. In each group of coffee-based agrosystem, we discussed the drivers of coffee production and explored potential avenues to improve sustainability based on ecosystem services provision. We highlighted that the physical characteristics of the environment, topoclimate and soil characteristics, are the main drivers of injury profiles and of resulting yield losses. Cropping practices and pest and disease management first need to be adapted to these physical characteristics. Where topoclimate and soils favour pest and disease development, potentially leading to heavy yield losses, system diversification can enhance ecosystem service provision, including production of other crops, thus helping to offset low coffee production. Where physical environmental characteristics hamper pests and diseases, increasing ecosystem service provision by incorporating shade trees may be considered, provided that coffee production is not significantly reduced. We conclude that there is an acute need to quantify losses caused by pests and diseases in agroforestry systems, in order to provide a rational basis for growers’ decisions and to better determine the value of economic incentives needed for ecosystem service provision.