Coffee agroforestry systems capable of reducing disease-induced yield and economic losses while providing multiple ecosystem services
Introduction
Regulation of pests and diseases is an important ecosystem service worldwide. Pests and diseases cause severe crop losses, threatening agricultural production and reducing the food security and incomes of farmers (Oerke et al., 1994; Oerke, 2006). In the countries of Central America in 2011–2012, an outbreak of coffee leaf rust, due to the pathogen Hemileia vastatrix, along with suboptimal cropping practices, caused significant yield losses leading to an average yield reduction of 20% in the following years. Since then, coffee production in the region has continued to be low (Cerda et al., 2017b).
Injury profiles, i.e. a given combination of injury levels caused by a range of diseases and pests (Savary et al., 2006), can differ dramatically according to crop systems in terms of encountered injuries and the levels they reach. A specific crop system can help regulate some diseases but promote others. In coffee systems, for instance, it is known that full-sun crops are more prone to coffee berry disease (Colletotrichum kahawae); branch dieback, a syndrome exacerbated by Colletrotrichum fungi; brown eye spot (Cercospora coffeicola), and Phoma leaf blight (Phoma costarricensis). In contrast, shaded coffee systems are deemed prone to coffee leaf rust (Hemileia vastatrix), American leaf spot disease (Mycena citricolor), coffee wilt disease (Fusarium xylarioides) and thread blight (Corticium koleroga) (Avelino et al., 2011, 2018). Quantifying the overall pest and disease regulation service within coffee systems is therefore difficult; however, valuing this service can be achieved through crop loss assessments (Avelino et al., 2011, 2018; Cerda et al., 2017a). Crop systems that help reduce crop losses due to pests and diseases are those that will be of interest to farmers, even if some pests and diseases are present.
Crop losses due to pests and diseases include losses in quantity and/or quality of the crop product (Oerke, 2006), normally resulting in economic losses (Nutter et al., 1993). Both primary and secondary crop losses should be considered. Primary crop losses are those caused in the specific year when pest and disease injuries occur, while secondary crop losses are those resulting from negative impacts of these pests and diseases in subsequent years (Zadoks and Schein, 1979; Avelino et al., 2015). For instance, foliar diseases in coffee cause defoliation and death of branches that will no longer bear fruits, leading to secondary losses.
A recent study on coffee has shown that the secondary yield losses (38%) can be higher and therefore more important than primary yield losses (26%) caused by foliar pests and diseases (Cerda et al., 2017b). Since coffee has a biennial production rhythm characterized by a repetitive cycle of high production one year and low production the following year (DaMatta et al., 2007), the interaction between the biennial behavior of production and pests and diseases impacts on coffee yield can lead to strong economic fluctuation and instability for coffee farmers. The main coffee diseases to consider in Latin America and the Caribbean are coffee leaf rust (H. vastatrix), American leaf spot (Mycena citricolor), brown eye spot (Cercospora coffeicola) and anthracnose (Colletotrichum gloeosporioides); ultimately branch dieback must be considered, which is itself aggravated by a complex of opportunistic fungi.
Given such a problematic scenario, combating coffee diseases is a priority for governments and private sectors in the Latin American and Caribbean region. There is a need to better understand how different management practices and the agroecosystem structure influence crop losses. Coffee is produced under a wide variety of different conditions with different levels of management intensity. There are coffee plantations in monocultures (full sun) and shaded coffee plantations which range from simple to highly complex agroforestry systems (Toledo and Moguel, 2012).
An important and major challenge is to design coffee agroforestry systems capable of regulating pests and diseases and reducing resulting losses while, at the same time, maintaining other ecosystem services necessary for farmers and for society as a whole. For instance, for farmers and their families, the provision of diversified products such as fruits, timber, firewood and others from coffee agroforestry systems is important for household income and food security (Rice, 2008). The maintenance of soil fertility (a regulation service) is of interest to farmers, given that their production depends in great part on soil quality (Müller et al., 2015). For the society in general, carbon sequestration is a key regulation service, as it contributes to the mitigation of climate change (MEA, 2005). All of these services can be provided individually or simultaneously by coffee systems, depending on the type of agroforestry system and its management.
It is also important to understand the relationships among different ecosystem services, since management decisions that improve the delivery of a particular service can affect other services (Cheatham et al., 2009; Mora et al., 2016). To increase beneficial or synergetic relationships, trade-offs between ecosystem services must be minimized and synergies promoted (Iverson et al., 2014; Rapidel et al., 2015). In the case of multiple cropping, such as agroforestry systems, knowledge of the trade-offs and synergies among ecosystem services is important for improving the management of the biodiversity. This knowledge is a necessary step towards the ecological intensification of agriculture, i.e. an agricultural intensification to increase yields with improved ecosystem services and reduced negative externalities (Kremen and Miles, 2012; Geertsema et al., 2016). It is also important to estimate the monetary values of ecosystem services and use this information in the assessment of relationships, because this can shed light on the magnitude of trade-offs or synergies (Peh et al., 2016). Several recent studies have already demonstrated the usefulness of assessing relationships among ecosystem services to guide farm management decisions. For instance, trade-off analysis in agroforestry systems (with coffee and cocoa especially) have yielded strategic recommendations to improve the design and management of different types of such systems (Wade et al., 2010; Meylan et al., 2013; Somarriba et al., 2013; Cerda et al., 2017a).
With this research, we aimed to identify the most promising coffee agroforestry systems (CAFs) that can serve as production models for farmers. Here we define ‘promising’ CAFs as those capable of reducing yield and economic losses due to diseases while also providing other ecosystem services. We studied a wide variety of coffee agroecosystems with different cropping practices, contrasting types of shade canopies and different altitudinal locations. Our specific objectives were to (1) quantify the delivery of provisioning services (coffee yield, agroforestry products, cash flow, value of domestic consumption) in different CAFs; (2) quantify indicators of regulation services (coffee yield losses and economic losses, incidence of diseases) plus indicators of maintenance of soil fertility and carbon sequestration in the aboveground biomass; and (3) analyze the relationships among those ecosystem services in order to identify the most promising CAFs. From these promising CAFs, we also aimed to derive technical recommendations to prevent losses from diseases. The indicators of ecosystem services chosen in this study are relevant for characterizing the basic needs of farmers’ families, the natural resources in agroforestry systems and the environment in general (Rice, 2011; Somarriba et al., 2013; Cerda et al., 2014; Pinoargote et al., 2016).
Section snippets
Location and coffee plot network
To characterize the delivery of multiple ecosystem services in coffee agroforestry plots, we collected data for two years (2014–2015) in 61 coffee plots in a research network established in Turrialba, Costa Rica. Turrialba is characterized as a premontane wet forest life zone (with mean annual rainfall = 2781 mm and a mean annual temperature = 22.2 °C; 10 year averages), where coffee is grown from 600 to 1400 m above sea level (m.a.s.l.). To sample the diverse set of conditions under which
Results
We found 21 significant relationships (p < 0.05) between yield losses and economic losses and ecosystem service indicators (out of total 48 regressions). We identified six promising CAFs that hold the greatest potential to provide multiple ecosystem services simultaneously. We first present figures of relationships among different ecosystem service provisions. In each figure, the types of coffee agroecosystems can be differentiated, and the six most promising CAFs are identified. We then
Yield losses to identify crop systems tolerant to diseases
Primary and secondary yield losses were positively related to coffee leaf rust and dieback that leads to the death of productive branches, considered as the main yield-reducing factor (Cerda et al., 2017b). However, we highlight as an important finding that the coffee plots with the lower primary and secondary losses were not necessarily associated with lower disease levels. For instance, among the six most promising CAFs, the percentage of coffee leaf rust ranged from 24% to 63%, but their
Conclusions
Identifying agroforestry systems that enhance the regulation of diseases while delivering good yields and other ecosystem services can help improve the sustainability of coffee farming by providing farmers and technicians with successful coffee production models. The six most promising CAFs identified in this study belonged to different types of agroforestry systems and management strategies. This is an important finding because such systems represent several options to follow (imitate) for the
CRediT authorship contribution statement
Rolando Cerda: Conceptualization, Methodology, Formal analysis, Investigation, Data curation, Writing - original draft, Writing - review & editing. Jacques Avelino: Conceptualization, Methodology, Investigation, Writing - review & editing, Supervision. Celia A. Harvey: Resources, Writing - review & editing, Visualization. Christian Gary: Resources, Conceptualization, Writing - review & editing. Philippe Tixier: Formal analysis, Investigation, Data curation. Clémentine Allinne:
Declaration of competing interest
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Acknowledgements
This research was supported by the CASCADE project Ecosystem-Based Adaptation for Smallholder Subsistence and Coffee Farming Communities in Central America, funded by the International Climate Initiative (ICI). The German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB) supports this initiative on the basis of a decision adopted by the German Bundestag. This research is also a product of a study grant implemented by the Agence inter-établissements of
References (45)
- et al.
The intensity of a coffee rust epidemic is dependent on production situations
Ecol. Model.
(2006) - et al.
Effects of shade, altitude and management on multiple ecosystem services in coffee agroecosystems
Eur. J. Agron.
(2017) - et al.
Measures of the effects of agricultural practices on ecosystem services
Ecol. Econ.
(2007) - et al.
Combining a typology and a conceptual model of cropping system to explore the diversity of relationships between ecosystem services: the case of erosion control in coffee-based agroforestry systems in Costa Rica
Agric. Syst.
(2013) - et al.
Synergies between biodiversity conservation and ecosystem service provision: lessons on integrated ecosystem service valuation from a Himalayan protected area, Nepal
Ecosyst. Serv.
(2016) Agricultural intensification within agroforestry: the case of coffee and wood products
Agric. Ecosyst. Environ.
(2008)- et al.
Carbon stocks and cocoa yields in agroforestry systems of Central America
Agric. Ecosyst. Environ.
(2013) - et al.
Economic constraints as drivers of coffee rust epidemics in Nicaragua
Crop Protect.
(2020) - et al.
Management strategies for maximizing carbon storage and tree species diversity in cocoa-growing landscapes
Agric. Ecosyst. Environ.
(2010) Fitopatología
(2005)