Matter flows and balances in urban vegetable gardens of Bobo Dioulasso, Burkina Faso (West Africa)

Many efforts are undertaken for sustaining urban agriculture in African cities. This study therefore investigated nutrient management practices in urban vegetable gardens of Bobo Dioulasso, Burkina Faso (West Africa). Nitrogen (N), phosphorus (P), potassium (K), and carbon (C) fluxes were quantified and nutrient balances calculated for three gardens representing the typical commercial gardening + field crops and livestock system (cGCL) and three gardens representing the commercial gardening + semi-commercial field crop system (cGscC). Nutrient and C balances were similarly positive in both production systems reaching annual averages of 688 kg N ha -1, 251 kg P ha-1 yr-1, 189 kg K ha-1, and 31 t C ha-1. Inputs in all gardens exceeded the amounts recommended by the extension service. Gaseous emissions of N and C represented important pathways of N and C losses. The highest emission rates occurred during the hottest periods of the day and the peaks were observed after fertilizer applications. Management recommendations should be geared towards increasing nutrient use efficiencies by better tailoring nutrient availability to crop demand and adjusted fertilization techniques to mitigate N losses.

Decent work?

Pastoralism and ranching are two different rangeland-based livestock systems in dryland areas of East Africa. Both usually operate under low and irregular rainfall and consequently low overall primary biomass production of high spatial and temporal heterogeneity. Both are usually located far from town centres, market outlets and communication, medical, educational, banking, insurance and other infrastructure. Whereas pastoralists can be regarded as self-employed, gaining their livelihood from managing their individually owned livestock on communal land, ranches mostly employ herders as wage labourers to manage the livestock owned by the ranch on the ranches’ own land property. Both production systems can be similarly labour intensive and – with regard to the livestock management – require the same type of work, whether carried out as self-employed pastoralist or as employed herder on a work contract. Given this similarity, the aim of this study was to comparatively assess how pastoralists and employed herders in northern Kenya view their working conditions, and which criteria they use to assess hardship and rewards in their daily work and their working life. Their own perception is compared with the concept of Decent Work developed by the International Labour Organisation (ILO). Samburu pastoralists in Marsabit and Samburu Districts as well as herders on ranches in Laikipia District were interviewed. A qualitative analysis of 47 semi-structured interviews yielded information about daily activities, income, free time, education and social security. Five out of 22 open interviews with pastoralists and seven out of 13 open interviews with employed herders fully transcribed and subjected to qualitative content analysis to yield life stories of 12 informants. Pastoralists consider it important to have healthy and satisfied animals. The ability to provide food for their family especially for the children has a high priority. Hardships for the pastoralists are, if activities are exhausting, and challenging, and dangerous. For employed herders, decent conditions are if their wages are high enough to be able to provide food for their family and formal education for their children. It is further most important for them to do work they are experienced and skilled in. Most employed herders were former pastoralists, who had lost their animals due to drought or raids. There are parallels between the ILO ‘Decent Work’ concept and the perception of working conditions of pastoralists and employed herders. These are, for example, that remuneration is of importance and the appreciation by either the employer or the community is desired. Some aspects that are seen as important by the ILO such as safety at work and healthy working conditions only play a secondary role to the pastoralists, who see risky and dangerous tasks as inherent characteristics of their efforts to gain a livelihood in their living environment.

An integrated assessment of resource use strategies in the Borana pastoral system of southern Ethiopia

In the pastoral production systems, mobility remains the main technique used to meet livestock’s fodder requirements. Currently, with growing challenges on the pastoral production systems, there is urgent need for an in-depth understanding of how pastoralists continue to manage their grazing resources and how they determine their mobility strategies. This study examined the Borana pastoralists’ regulation of access to grazing resources, mobility practices and cattle reproductive performances in three pastoral zones of Borana region of southern Ethiopia. The central objective of the study was to contribute to the understanding of pastoral land use strategies at a scale relevant to their management. The study applied a multi-scalar methodological approach that allowed zooming in from communal to individual herd level. Through participatory mapping that applied Google Earth image print out as visual aid, the study revealed that the Borana pastoralists conceptualized their grazing areas as distinctive grazing units with names, borders, and specific characteristics. This knowledge enables the herders to communicate the condition of grazing resources among themselves in a precise way which is important in management of livestock mobility. Analysis of grazing area use from the participatory maps showed that the Borana pastoralists apportion their grazing areas into categories that are accessed at different times of the year (temporal use areas). This re-organization is an attempt by the community to cope with the prevailing constraints which results in fodder shortages especially during the dry periods. The re-organization represents a shift in resource use system, as the previous mobility practice across the ecologically varied zones of the rangelands became severely restricted. Grazing itineraries of 91 cattle herds for over 16 months obtained using the seasonal calendar interviews indicated that in the areas with the severest mobility constraints, the herders spent most of their time in the year round use areas that are within close proximity to the settlements. A significant change in mobility strategy was the disallowing of foora practice by the communities in Dirre and Malbe zones in order to reduce competition. With the reduction in mobility practices, there is a general decline in cattle reproductive parameters with the areas experiencing the severest constraints showing the least favourable reproductive performances. The study concludes that the multi-scalar methodology was well suited to zoom into pastoral grazing management practices from communal to individual herd levels. Also the loss of mobility in the Borana pastoral system affects fulfilment of livestock feed requirements thus resulting in reduced reproductive performances and herd growth potentials. While reversal of the conditions of the situations in the Borana rangelands is practically unfeasible, the findings from this research underscore the need to protect the remaining pastoral lands since the pastoral production system remains the most important livelihood option for the majority of the Borana people. In this regards the study emphasises the need to adopt and domesticate regional and international policy frameworks such as that proposed by the African Union in 2010.

Regelbasiertes Reasoning auf massiv paralleler Hardware

Eine wesentliche Funktionalität bei der Verwendung semantischer Technologien besteht in dem als Reasoning bezeichneten Prozess des Ableitens von impliziten Fakten aus einer explizit gegebenen Wissensbasis. Der Vorgang des Reasonings stellt vor dem Hintergrund der stetig wachsenden Menge an (semantischen) Informationen zunehmend eine Herausforderung in Bezug auf die notwendigen Ressourcen sowie der Ausführungsgeschwindigkeit dar. Um diesen Herausforderungen zu begegnen, adressiert die vorliegende Arbeit das Reasoning durch eine massive Parallelisierung der zugrunde liegenden Algorithmen und der Einführung von Konzepten für eine ressourceneffiziente Ausführung. Diese Ziele werden unter Berücksichtigung der Verwendung eines regelbasierten Systems verfolgt, dass im Gegensatz zur Implementierung einer festen Semantik die Definition der anzuwendenden Ableitungsregeln während der Laufzeit erlaubt und so eine größere Flexibilität bei der Nutzung des Systems bietet. Ausgehend von einer Betrachtung der Grundlagen des Reasonings und den verwandten Arbeiten aus den Bereichen des parallelen sowie des regelbasierten Reasonings werden zunächst die Funktionsweise von Production Systems sowie die dazu bereits existierenden Ansätze für die Optimierung und im Speziellen der Parallelisierung betrachtet. Production Systems beschreiben die grundlegende Funktionalität der regelbasierten Verarbeitung und sind somit auch die Ausgangsbasis für den RETE-Algorithmus, der zur Erreichung der Zielsetzung der vorliegenden Arbeit parallelisiert und für die Ausführung auf Grafikprozessoren (GPUs) vorbereitet wird. Im Gegensatz zu bestehenden Ansätzen unterscheidet sich die Parallelisierung insbesondere durch die gewählte Granularität, die nicht durch die anzuwendenden Regeln, sondern von den Eingabedaten bestimmt wird und sich damit an der Zielarchitektur orientiert. Aufbauend auf dem Konzept der parallelen Ausführung des RETE-Algorithmus werden Methoden der Partitionierung und Verteilung der Arbeitslast eingeführt, die zusammen mit Konzepten der Datenkomprimierung sowie der Verteilung von Daten zwischen Haupt- und Festplattenspeicher ein Reasoning über Datensätze mit mehreren Milliarden Fakten auf einzelnen Rechnern erlauben. Eine Evaluation der eingeführten Konzepte durch eine prototypische Implementierung zeigt für die adressierten leichtgewichtigen Ontologiesprachen einerseits die Möglichkeit des Reasonings über eine Milliarde Fakten auf einem Laptop, was durch die Reduzierung des Speicherbedarfs um rund 90% ermöglicht wird. Andererseits kann der dabei erzielte Durchsatz mit aktuellen State of the Art Reasonern verglichen werden, die eine Vielzahl an Rechnern in einem Cluster verwenden.

Ecosystem services and adaptation for agriculture and food security: analysis of two decades (1991–2011) of financing by the Global Environment Facility

Investing in global environmental and adaptation benefits in the context of agriculture and food security initiatives can play an important role in promoting sustainable intensification. This is a priority for the Global Environment Facility (GEF), created in 1992 with a mandate to serve as financial mechanism of several multilateral environmental agreements. To demonstrate the nature and extent of GEF financing, we conducted an assessment of the entire portfolio over a period of two decades (1991–2011) to identify projects with direct links to agriculture and food security. A cohort of 192 projects and programs were identified and used as a basis for analyzing trends in GEF financing. The projects and programs together accounted for a total GEF financing of US$1,086.8 million, and attracted an additional US$6,343.5 million from other sources. The value-added of GEF financing for ecosystem services and resilience in production systems was demonstrated through a diversity of interventions in the projects and programs that utilized US$810.6 million of the total financing. The interventions fall into the following four main categories in accordance with priorities of the GEF: sustainable land management (US$179.3 million), management of agrobiodiversity (US$113.4 million), sustainable fisheries and water resource management (US$379.8 million), and climate change adaptation (US$138.1 million). By aligning GEF priorities with global aspirations for sustainable intensification of production systems, the study shows that it is possible to help developing countries tackle food insecurity while generating global environmental benefits for a healthy and resilient planet.