Equipement et Technologie
Le volet « Equipement et technologie » met l’accent sur les innovations en matière d’équipement, de technologie et de techniques de production, de traitement et d’utilisation de la biomasse alimentaire et non-alimentaire.
La demande de biomasse alimentaire et non-alimentaire augmente en Afrique et dans le monde en raison de la croissance démographique, des changements de régimes alimentaires et du passage des économies basées sur les combustibles fossiles aux économies basées sur la biomasse. Cependant, la réalisation et le maintien de la sécurité alimentaire en Afrique reste un problème important. La sécurité alimentaire peut être directement atteinte grâce à une production, une transformation et une consommation adéquates de la biomasse alimentaire; ou indirectement par la génération de revenus et par des économies de dépenses grâce au traitement et à l’utilisation de la biomasse non-alimentaire ou des déchets. Dans tous les cas, de nouvelles machines, technologies et techniques adaptées au contexte africain et qui soutiennent les innovations dans les secteurs de la production, de la transformation et de la consommation de la biomasse sont nécessaires.
Ce champ thématique comporte des contributions associées aux :
- Équipements et machines pour la production et le traitement de la biomasse, par exemple, les machines d’épluchage et de récolte du manioc
- Technologies et techniques de traitement et d’utilisation de la biomasse, par exemple, les méthodes thermiques, chimiques et biochimiques pour convertir la biomasse en énergie ou en matières premières industrielles
- Exemples de recyclage, d’utilisations couplées et en cascade de la biomasse qui aident à réduire la consommation globale de biomasse ainsi que les déchets de biomasse
Coordonnateur de thème: Charles Tortoe
Frank Susanne, Fürst Christine, Pietzsch Frank. 2015. Cross-Sectoral Resource Management: How Forest Management Alternatives Affect the Provision of Biomass and Other Ecosystem Services. Forests
Integrated forest management is faced with the challenge that the contribution of forests to economic and ecological planning targets must be assessed in a socio-ecological system context. This paper introduces a way to model spatio-temporal dynamics of biomass production at a regional scale in order to derive land use strategies that enhance biomass provision and avoid trade-offs for other ecosystem services. The software platform GISCAME was employed to bridge the gap between local land management decisions and regional planning by linking growth and yield models with an integrative mesoscale modeling and assessment approach. The model region is located in Saxony, Germany. Five scenarios were simulated, which aimed at testing different alternatives for adapted land use in the context of climate change and increasing biomass demand. The results showed, for example, that forest conversion towards climate-change-adapted forest types had positive effects on ecological integrity and landscape aesthetics. In contrast, negative impacts on landscape aesthetics must be expected if agricultural sites were converted into short rotation coppices. Uncertainties with stem from assumptions regarding growth and yield models were discussed. Future developmental steps which consider, for example, accessibility of the resources were identified.
Folberth Christian, Yang Hong, Gaiser Thomas, Liu Junguo, Wang Xiuying, Williams Jimmy, Schulin, Rainer. 2014. Effects of ecological and conventional agricultural intensification practices on maize yields in sub-Saharan Africa under potential climate change. Environmental Research Letters (9)
Much of Africa is among the world's regions with lowest yields in staple food crops, and climate change is expected to make it more difficult to catch up in crop production in particular in the long run. Various agronomic measures have been proposed for lifting agricultural production in Africa and to adapt it to climate change. Here, we present a projection of potential climate change impacts on maize yields under different intensification options in Sub-Saharan Africa (SSA) using an agronomic model, GIS-based EPIC (GEPIC). Fallow and nutrient management options taken into account are (a) conventional intensification with high mineral N supply and a bare fallow, (b) moderate mineral N supply and cowpea rotation, and (c) moderate mineral N supply and rotation with a fast growing N fixing tree Sesbania sesban. The simulations suggest that until the 2040s rotation with Sesbania will lead to an increase in yields due to increasing N supply besides improving water infiltration and soils' water holding capacity. Intensive cultivation with a bare fallow or an herbaceous crop like cowpea in the rotation is predicted to result in lower yields and increased soil erosion during the same time span. However, yields are projected to decrease in all management scenarios towards the end of the century, should temperature increase beyond critical thresholds. The results suggest that the effect of eco-intensification as a sole means of adapting agriculture to climate change is limited in Sub-Saharan Africa. Highly adverse temperatures would rather have to be faced by improved heat tolerant cultivars, while strongly adverse decreases in precipitation would have to be faced by expanding irrigation where feasible.
Chala Bilhate, Oechsner Hans, Latif Sajid, Müller Joachim. 2018. Biogas Potential of Coffee Processing Waste in Ethiopia. Sustainability (10)
Primary coffee processing is performed following the dry method or wet method. The dry method generates husk as a by-product, while the wet method generates pulp, parchment, mucilage, and waste water. In this study, characterization, as well as the potential of husk, pulp, parchment, and mucilage for methane production were examined in biochemical methane potential assays performed at 37 °C. Pulp, husk, and mucilage had similar cellulose contents (32%). The lignin contents in pulp and husk were 15.5% and 17.5%, respectively. Mucilage had the lowest hemicellulose (0.8%) and lignin (5%) contents. The parchment showed substantially higher lignin (32%) and neutral detergent fiber (96%) contents. The mean specific methane yields from husk, pulp, parchment, and mucilage were 159.4 ± 1.8, 244.7 ± 6.4, 31.1 ± 2.0, and 294.5 ± 9.6 L kg−1 VS, respectively. The anaerobic performance of parchment was very low, and therefore was found not to be suitable for anaerobic fermentation. It was estimated that, in Ethiopia, anaerobic digestion of husk, pulp, and mucilage could generate as much as 68 × 106 m3 methane per year, which could be converted to 238,000 MWh of electricity and 273,000 MWh of thermal energy in combined heat and power units. Coffee processing facilities can utilize both electricity and thermal energy for their own productive purposes.
Camacho-Villa Tania Carolina, Almekinders Conny, Hellin Jon, Martinez Cruz Tania Eulalia, Rendon Medel Roberto, Guevara Hernandez Francisco, Beuchelt Tina D, Govaerts Bram. 2016. The evolution of the MasAgro hubs: responsiveness and serendipity as drivers of agricultural innovation in a dynamic and heterogeneous context. The Journal of Agricultural Education and Extension,
Little is known about effective ways to operationalize agricultural innovation processes. We use the MasAgro program in Mexico (which aims to increase maize and wheat productivity, profitability and sustainability), and the experiences of middle level ‘hub managers’, to understand how innovation processes occur in heterogeneous and changing contexts. Design/methodology/approach: We use a comparative case study analysis involving research tools such as documentary review, key informant interviews, focus group discussions, and reflection workshops with key actors. Findings: Our research shows how a program, that initially had a relatively narrow technology focus, evolved towards an innovation system approach. The adaptive management of such a process was in response to context-specific challenges and opportunities. In the heterogeneous context of Mexico this results in diverse ways of operationalization at the hub level, leading to different collaborating partners and technology portfolios. Practical implications: MasAgro experiences merit analysis in the light of national public efforts to transform agricultural advisory services and accommodate pluralistic agricultural extension approaches in Latin America. Such efforts need long-term coherent macro level visions, frameworks and support, while the serendipitous nature of the process requires meso-level implementers to respond and adapt to and move the innovation process forward. Originality/value: This paper contributes to the debate on how to operationalize large programs by showing that the innovation support arrangements enacted in the field should allow for diversity and have a degree of flexibility to accommodate heterogeneous demands from farmers in different contexts as well as continuous changes in the politico- institutional environment.
Callo-Concha Daniel, Ewert Frank. 2014. Using the Concepts of Resilience, Vulnerability and Adaptability for the Assessment and Analysis of Agricultural Systems. Change and Adaptation in Socio-Ecological Systems, Volume 1, Issue 1, ISSN (Online) 2300-3669
Resilience, vulnerability and adaptability have emerged as dominant concepts in the study of disturbance and change of social-ecological systems. We analyze the conceptual, methodological and operational aspects in using these concepts for the assessment and analysis of agricultural systems and try to identify differences and possible overlaps between them. The analysis is performed considering a number of published studies on agricultural systems over a wide geographical range where these concepts have been applied. Our results show a clear conceptual overlap and often the exchangeable use of the concepts. Furthermore, the driving methodological and operational criteria for their application could not be separated unambiguously. It was, thus, difficult to identify guiding principles for the operational application of the individual concepts. We stress that the operationalization of these concepts requires consistency in the approaches and protocols to ensure their coherent use. We also argue that the conceptual and operational integration of resilience, vulnerability and adaptability would perhaps lead to a more complete portrayal of the behavior of agricultural systems in changing situations. But this requires more research including the development of operational protocols for which the premises of complexity, participation and functionality seem key.
Kiatkamjon Intani, Sajid Latif, Zebin Cao, Joachim Müller. 2018. Characterisation of biochar from maize residues produced in a self-purging pyrolysis reactor. Bioresource Technology (265): 224–235 pp.
Response surface methodology was used to optimise pyrolysis conditions to produce biochar from maize residues (cobs, husks, leaves and stalks). The aim was to obtain biochar with good potential as an additive for composting. Mathematical models were developed to explain the experimental responses of volatile matter content (VM), ash content (AC), pH and electrical conductivity (EC) to the operating parameters such as temperature, heating rate and holding time. The temperature had the most significant influence on biochar properties. AC, pH and EC significantly increased (p < 0.05) with increasing temperature, while the VM decreased. The holding time showed less effect on the responses, while the heating rate had insubstantial effect. Under the optimal conditions, the husk and leaf biochar had higher AC (11.42 and 26.55%), pH (10.96 and 11.51), and EC (12.37 and 6.79 mS/cm), but lower VM (7.38 and 8.39%) than those of cob and stalk biochar.