Life cycle assessment of carbon and energy balances in Jatropha production systems of Burkina Faso

Modern bioenergy offers several advantages to Burkina Faso, a country that is heavily dependent on imported fossil fuel and greatly relying on traditional biomass use. In this context, Jatropha curcas has been recently introduced as a low-maintenance energy crop with the potential to increase energy security while contributing to land rehabilitation and climate change mitigation. This study identified J. curcas cultivation systems practiced in Burkina Faso and analyzed their biomass dynamics and carbon (C) accrual over time as well as soil-C stocks. These data, together with the information on J. curcas seed transformation processes, were integrated in a life cycle assessment (LCA) of the greenhouse gas (GHG) emission and energy-saving potential of the complete biofuel production pathways. The studied J. curcas systems include interplanting with annual crops, intensely managed plantations, afforestation of marginal land, plantings along contour stone walls, and traditional living fences. Destructive above- and below-ground biomass determination enabled the identification of growth stages and development of allometric equations relating total shoot and root biomass with the stem diameter that showed very good fits (R²>0.9). Empirical growth models related woody biomass and tree age by a three-parametric non-linear logistic function. According to the model results, the biomass production of J. curcas plants peaked between the 10th and 15th year after planting, with intercropping and intensely managed systems showing the highest stock (21 t ha-1). Afforestation systems on marginal land had the lowest biomass stocks (-1), and could not be modeled due to drastic mortality at an early age in the absence of maintenance. Soil analysis did not reveal a clear trend of soil organic carbon (SOC) dynamics over time when comparing the soil carbon status in 4-year-old J. curcas sites with that in the reference cropland. Only J. curcas living fences exhibited significantly higher SOC stocks in the top 20 cm soil based on a chronosequence study covering 20 years of J. curcas cultivation. All J. curcas production pathways showed GHG emission reductions and energy savings of up to 82% and 85%, respectively, as opposed to fossil fuel. Decentralized production of straight vegetable oil and its consumption in stationary diesel engines showed the best performance. However, J. curcas plantation systems had very low land-use efficiency (6.5-9.5 GJ ha-1) and thus a high land-use replacement potential. Carbon-stock gains were attained when introducing J. curcas on croplands. However, the displacement of agricultural activities to other areas can indirectly result in C losses. Human energy accounted for 24% of the total energy balance, indicating high manual labor requirements in small-scale J. curcas systems. Monetary valuation of C offsets via carbon trading schemes showed returns below US$ 350 over 20 years. Overall, J. curcas biofuel production can contribute to climate change mitigation and national energy independency. However, due to low land-use efficiency, high labor requirements and the unsuccessful cultivation on marginal land, J. curcas becomes a direct competitor with food crops and is a not viable option for smallholder farmers. Whereas J. curcas cultivation is yet to be intensified through improved plant material and optimized agronomic management, the traditional hedge systems are a preferable option for seed production as they offer additional benefits of erosion control and field protection to farmers’ fields.Ökobilanzierung der Kohlenstoff- und Energiebilanzen von Jatropha Produktionssystemen in Burkina Faso Moderne Bioenergie stellt für Burkina Faso eine attraktive Alternative zu Erdölimporten und traditioneller Biomassenutzung dar. In diesem Kontext wurde Jatropha curcas bekannt als eine sehr anspruchslose Energiepflanze, dessen Anbau zur Rekultivierung von marginalen Standorten, zur nationalen Energieversorgung und zum Klimaschutz beitragen kann. Im Rahmen der vorliegenden Forschungsarbeit wurden existierende J. curcas Systeme in Burkina Faso identifiziert und auf ihre Biomasse- und Bodenkohlenstoff-Dynamik untersucht. Zusammen mit Informationen zur Weiterverarbeitung der Samen wurden alle Daten in einem Life Cycle Assessment (LCA) zur Berechnung der Treibhausgasemissionen und des Energieeinsparungspotenzials der J. curcas Bioenergie-Produktionssysteme zusammengeführt. Insgesamt konnten fünf J. curcas Systeme identifiziert werden: Mischanbau mit einjährigen Kulturen, intensiv bewirtschaftete Plantagen, Aufforstung von marginalen Flächen, traditionelle Lebendhecken und Hecken entlang von Kontursteinmauern. Durch direkte Messungen von ober-und unterirdischer Biomasse der J. curcas Bäume konnten unterschiedliche Wachstumsphasen definiert und allometrische Modelle zur indirekten Biomassebestimmung entwickelt werden. Es zeigte sich eine sehr starke (R²>0.9) allometrische Beziehung zwischen sowohl Holz- als auch Wurzelmasse und Stammdurchmesser. Des Weiteren konnten empirische Wachstumsmodelle zur Vorhersage der Holzbiomasse in Abhängigkeit des Alters erstellt werden. Entsprechend der Modelle erreicht die Biomasseproduktion ihren Höhepunkt zwischen dem zehnten und fünfzehnten Wachstumsjahr. Jatropha curcas im Mischanbau und in intensiv bewirtschafteten Plantagen erreichte die höchsten Biomassewerte (21 t ha-1), während das Aufforstungssystem mit einer Biomasse von weniger als 0.1 t ha-1 die geringsten Werte aufwies. Aufgrund der hohen Mortalität der jungen Bäume auf den marginalen Standorten konnte das Biomassewachstum dieses Systems nicht modelliert werden. Vergleichende Bodenanalysen von vier Jahre alten J. curcas Standorten mit Flächen unter einjährigen Kulturen ergaben keine eindeutige Tendenz von Veränderungen des Bodenkohlenstoffs. Nur in einer Chronosequenz von Böden unter Lebendhecken über 20 Jahre konnte ein signifikanter Anstieg des Kohlenstoffs in den ersten 20 cm des Bodens festgestellt werden. Für alle Produktionswege der J. curcas Bioenergie konnten eine bis zu 82% hohe Verringerung der Treibhausgasemissionen und bis zu 85% Energieeinsparungen im Vergleich zu fossilen Brennstoffen festgestellt werden. Die dezentrale Produktion von Pflanzenöl und dessen Verbrauch in stationären Dieselmotoren zeigte die besten Ergebnisse. Eine sehr geringe Landnutzungseffizienz (6.5-9.5 GJ ha-1) der J. curcas Plantagensysteme erhöhen jedoch den Druck auf andere Landnutzungsformen. Auch wenn die Integration von J. curcas in landwirtschaftliche Systeme zu einer größeren Kohlenstoffspeicherung führt, kann die Verdrängung der Nahrungsmittel von den Flächen zu indirekten Landnutzungsänderungen und dortigen Kohlenstoffverlusten führen. Zusätzlich bedarf die Kultivierung von J. curcas in kleinbäuerlichen Systemen einen sehr hohen körperlichen Arbeitsaufwand, der 24% der gesamten Energiebilanz konstituiert. Eine monetäre Bewertung der Kohlenstoffeinsparungen durch dessen Handel auf internationalen Märkten versprach nur geringfügige Erträge. Zusammenfassend kann gesagt werden, dass J. curcas Systeme in Burkina Faso sowohl zum Klimaschutz als auch zur Energiesicherung beitragen können. Durch die sehr geringe Landnutzungseffizienz, den hohen Arbeitsaufwand und die fehlende Ertragsleistung auf marginalen Standorten wird J. curcas jedoch zu einer direkten Konkurrenz zu Nahrungsmitteln und stellt keine praktikable Option für Kleinbauern dar. Solange der Anbau von J. curcas durch verbessertes Pflanzmaterial und optimiertes Management nicht intensiviert werden kann, sollte der Anbau von J. curcas in Heckensystemen vorgezogen werden. Diese bieten vielfältige Vorteile für die Bauern während die Samenproduktion zur Energieversorgung in ländlichen Gebieten beitragen kann

Forgone opportunities of large-scale agricultural investment: A comparison of three models of soya production in Central Mozambique

Agriculture is one of the main engines for prosperity and economic growth in Africa but effective agricultural strategies to support rural development and poverty alleviation are not yet identified. While state investment in the small-scale farming sector is minimal, and the medium-scale “emergent” household farm sector remains underrepresented, large-scale land investments are advocated as means to bring capital to rural areas and stimulate development. Yet, little empirical research has been done to contrast agricultural development strategies and to understand their strengths and weaknesses. We present an analysis of different soya production models - small-scale farmers, medium-scale mechanised emergent farmers, and large-scale commercial operations - and their socio-economic aspects in Central Mozambique. Based on purposefully collected data in 10 villages in Gurué district, our findings suggest that large-scale plantations create localized land scarcity and that the benefits from wage labour and local investments do not compensate rural populations for lost access to land. Small- and medium-scale soya farming also leads to decreasing land availability, but provides greater socio-economic benefits such as on-farm employment and work opportunities along the local value chain. Small- and medium-scale soya production increases on- and off-farm income and leads to spill-over effects to the local economy. Negative effects of these models of soya production on food production could not be detected; instead the cultivation of soya significantly increases maize yields grown in rotation. These findings suggest that small- and medium-scale commercial farming can compete with large-scale operations in key socio-economic parameters and that a concentration on large-scale investments can result in forgone opportunities regarding rural development and poverty reduction

Compensating farmers for ecosystem services: Lessons and an agenda for innovation

The CompensACTION Initiative aims to promote payments for ecosystem services (PES) to improve smallholder farmers’ incomes at large scales while incentivizing climate action, sustainable farming and other environmental outcomes. Key drivers for scaling up PES programs are increasing farmers’ benefits in PES schemes, using public finance to leverage private sector capital, and facilitating PES project readiness. Priority areas for action to meet the CompensACTION Initiative objectives are to: • Foster technical innovation and disruption to support low-cost, high- volume PES transactions. • Increase public and private investment to scale up PES programs. • Support public policy reform to establish national frameworks for PES schemes. • G7 members and other countries can play a leadership role in mobilizing action

Charcoal production in the Mopane woodlands of Mozambique: what are the trade-offs with other ecosystem services?

African woodlands form a major part of the tropical grassy biome and support the livelihoods of millions of rural and urban people. Charcoal production in particular is a major economic activity, but its impact on other ecosystem services is little studied. To address this, our study collected biophysical and social datasets, which were combined in ecological production functions, to assess ecosystem service provision and its change under different charcoal production scenarios in Gaza Province, southern Mozambique. We found that villages with longer histories of charcoal production had experienced declines in wood suitable for charcoal, firewood and construction, and tended to have lower perceived availabilities of these services. Scenarios of future charcoal impacts indicated that firewood and woody construction services were likely to trade-off with charcoal production. However, even under the most extreme charcoal scenario, these services were not completely lost. Other provisioning services, such as wild food, medicinal plants and grass, were largely unaffected by charcoal production. To reduce the future impacts of charcoal production, producers must avoid increased intensification of charcoal extraction by avoiding the expansion of species and sizes of trees used for charcoal production. This is a major challenge to land managers and policymakers in the area. This article is part of the themed issue ‘Tropical grassy biomes: linking ecology, human use and conservation’

Charcoal supply chains from Mabalane to Maputo: Who benefits?

AbstractIn urban centres of Mozambique, charcoal is the major energy source for cooking. Growing demand drives high wood extraction rates over increasing areas of miombo and mopane woodlands. Charcoal production can lead to changes in ecosystem service provision and woodland degradation while also significantly contributing to rural income and, possibly, poverty alleviation. As such, understanding charcoal production and trade has important implications for rural areas and for the sustainable development of woodland resources. Here, we investigate charcoal production and trade through empirical research conducted in Gaza Province, the main charcoal supply area for Maputo, Mozambique.We analyse the present structure of the main charcoal supply chains from Gaza province to Maputo and the profit distribution along them. Seven villages in the Mabalane district, Gaza, at different stages of engagement with the charcoal industry, were selected for investigation. We conducted household surveys and semi-structured interviews with key informants (village leaders, charcoal producers, licence holders, wholesalers, transporters and forest technicians), from May to October 2014.Our results highlight two main charcoal supply chains comprising four main actor groups a) Local small-scale operators producing charcoal on a small-scale with household labour, who sell to wholesalers b) Large-scale operators producing and commercialising large volumes of charcoal using migrant labour, who sell their own production to wholesalers. While charcoal production constitutes an important income source for rural households in Mabalane, under supply chain a) more than 90% of the monetary benefits do not reach local communities and remain with external agents. Two of the main factors impeding the generation of greater revenues at community level are: 1) bureaucratic burdens in obtaining charcoal commercialisation rights in the form of licences; and 2) weak institutional capacities for woodland resource governance.We conclude that access to markets and control over woodlands is key if local communities are to generate greater benefits from charcoal production while aiming at sustainable charcoal production. Strong local institutions for obtaining commercialisation rights and managing woodland resources have to be developed, while the restructuring of the licencing system in favour of small-scale producers and more rigorous control of the regulations could support this process

Social Cohesion as the Missing Link between Natural Resource Management and Peacebuilding: Lessons from Cocoa Production in Côte d’Ivoire and Colombia

Social cohesion plays a key role in processes of peacebuilding and sustainable development. Fostering social cohesion might present a potential to enhance the connection of natural resource management and peacebuilding and better functioning of sustainable land use systems. This contribution explores the nexus between social cohesion, natural resource management, and peacebuilding. We do so by (1) reviewing literature on the three concepts and (2) studying four different key action areas in the context of sustainable cocoa production for their potential to enhance social cohesion, namely (a) agroforestry; (b) cooperatives; (c) certification schemes; and (d) trade policies. Research is based on experience from cocoa production in two post-conflict countries, Côte d’Ivoire and Colombia. Our findings show that by fostering environmentally sustainable agricultural practices, these key action areas have a clear potential to foster social cohesion among cocoa producers and thus provide a valuable contribution to post-conflict peacebuilding in both countries. However, the actual effects strongly depend on a multitude of local factors which need to be carefully taken into consideration. Further, the focus in implementation of some of these approaches tends to be on increasing agricultural productivity and not directly on fostering cocoa farmers’ wellbeing and societal relations, and hence a shift toward social objectives is needed in order to strengthen these approaches as a part of overall peacebuilding strategies.Peer Reviewe