Mary Njenga

Real or Perceived: The Environmental Health Risks of Urban Sack Gardening in Kibera Slums of Nairobi, Kenya

Cities around the world are undergoing rapid urbanization, resulting in the growth of informal settlements or slums. These informal settlements lack basic services, including sanitation, and are associated with joblessness, low-income levels, and insecurity. Families living in such settlements may turn to a variety of strategies to improve their livelihoods and household food security, including urban agriculture. However, given the lack of formal sanitation services in most of these informal settlements, residents are frequently exposed to a number of environmental risks, including biological and chemical contaminants. In the Kibera slums of Nairobi, Kenya, households practice a form of urban agriculture called sack gardening, or vertical gardening, where plants such as kale and Swiss chard are planted into large sacks filled with soil. Given the nature of farming in slum environments, farmers and consumers of this produce in Kibera are potentially exposed to a variety of environmental contaminants due to the lack of formal sanitation systems. Our research demonstrates that perceived and actual environmental risks, in terms of contamination of food crops from sack gardening, are not the same. Farmers perceived exposure to biological contaminants to be the greatest risk to their food crops, but we found that heavy metal contamination was also significant risk. By demonstrating this disconnect between risk perception and actual risk, we wish to inform debates about how to appropriately promote urban agriculture in informal settlements, and more generally about the trade-offs created by farming in urban spaces.

Recycling nutrients from organic wastes in Kenya's capital city.

The question how much of the potential soil nutrients contained in urban wastes are being used and what processes are involved led to this study in the early 2000s. The issue is of central importance to understanding the potential benefits of a properly managed urban agriculture sector, since soil fertility is a major problem in Sub-Saharan Africa and urban wastes represent a large potential source of nutrients (Savala et al. 2003). Mougeot (1993, p.114) highlighted the importance of solid waste management and offered insights into the use of organic wastes by farmers as compost for their crops. When the Consultative Group on International Agricultural Research (CGIAR) was starting up its new system-wide program – Urban Harvest – in Africa in late 2000, stakeholders called for better documentation of these processes. In response, we came together from a number of institutions in Kenya to identify and map out the basic market and material flows for composts and manure in Nairobi and identify opportunities for improving the functioning of the system.

The socioeconomic and environmental impacts of wood energy value chains in Sub-Saharan Africa: a systematic map protocol

BackgroundThe vast majority of households in Sub-Saharan Africa (SSA) depend on wood energy—comprising firewood and charcoal—for their daily energetic needs. Such consumption trends are expected to remain a common feature of SSA’s wood energy production and supply chains, at least in the short- to medium-terms. Notwithstanding its importance, wood energy generally has low priority in SSA national policies. However, the use of wood energy is often considered a key driver of unsustainable management and negative environmental consequences in the humid and dry forests.To date, unsystematic assessments of the socio-economic and environmental consequences of wood energy use have underplayed its significance, thus further hampering policy debates. Therefore, a more balanced approach which considers both demand and supply dynamics is needed. This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in SSA.MethodsThe objective of this systematic map is to collate evidence from studies of environmental and socio-economic impacts of wood energy value chains, by considering both demand and supply within SSA. The map questions are framed using a Populations, Exposure, Comparators and Outcomes (PECO) approach. We name the supply and demand of wood energy as the “exposure,” composed of wood energy production, harvesting, processing, and consumption. The populations of interest include both the actors involved in these activities and the forest sites where these activities occur. The comparator is defined as those cases where the same wood energy activities occur with i) available/accessible alternative energy sources, ii) regulatory frameworks that govern the sector and iii) alternative technologies for efficient use. The outcomes of interest encompass both socioeconomic and environmental impacts that can affect more than the populations named above. For instance, in addition to the direct socioeconomic impacts felt by participants in the wood energy value chain, forest dwellers may experience livelihood changes due to forest degradation caused by external harvesters. Moreover, intensified deforestation in one area may concurrently lead to forest regeneration in another.

Conceptual Analysis: The Charcoal-Agriculture Nexus to Understand the Socio-Ecological Contexts Underlying Varied Sustainability Outcomes in African Landscapes

The production of charcoal is an important socio-economic activity in sub-Saharan Africa (SSA). Charcoal production is one of the leading drivers of rural land-use changes in SSA, although the intensity of impacts on the multi-functionality of landscapes varies considerably. Within a given landscape, charcoal production is closely interconnected to agriculture production both as major livelihoods, while both critically depend on the same ecosystem services. The interactions between charcoal and agricultural production systems can lead to positive synergies of impacts, but will more often than not result in trade-offs and even vicious cycles. Such sustainability outcomes vary from one site to another due to the heterogeneity of contexts, including agricultural production systems that affect the adoption of technologies and practices. Trade-offs or cases of vicious cycles occur when one-off resource exploitation of natural trees for charcoal production for short-term economic gains permanently impairs ecosystem functions. Given the fact that charcoal, as an important energy source for the growing urban populations and an essential livelihood for the rural populations, cannot be readily substituted in SSA, there must be policies to support charcoal production. Policies should encourage sustainable technologies and practices, either by establishing plantations or by encouraging regeneration, whichever is more suitable for the local environment. To guide context-specific interventions, this paper presents a new perspective - the charcoal-agriculture nexus - aimed at facilitating the understanding of the socio-economic and ecological interactions of charcoal and agriculture production. The nexus especially highlights two dimensions of the socio-ecological contexts: charcoal value chains and tenure systems. Combinations of the two are assumed to underlie varied socio-economic and ecological sustainability outcomes by conditioning incentive mechanisms to affect the adoption of technologies and practices in charcoal and agriculture productions. Contrasting sustainability outcomes from East Africa are presented and discussed through the lens of the charcoal-agriculture nexus. The paper then concludes by emphasizing the importance of taking into account the two-dimensional socio-ecological contexts into effective policy interventions to turn charcoal-agriculture interactions into synergies.

Benefits and Selected Health Risks of Urban Dairy Production in Nakuru, Kenya

Health risks from food production in urban areas are attracting increased international attention, especially in poor countries with rapid urbanization where urban farming is widely practiced to mitigate hunger and poor nutrition as well as reduce food expenditures. This study examines a selected range of health risks as compared to the benefits for an urban population for which a considerable quantity of background data are available, namely Nakuru municipality in Kenya. The research was carried out in conjunction with a related survey of crop-livestock-waste interactions in the same town, described in the previous chapter.

Crop–Livestock–Waste Interactions in Nakuru’s Urban Agriculture

As a complement to the research in Nairobi presented in the previous chapter, which mapped materials and market flows of nutrients in Kenya’s capital city, this chapter presents a more in-depth picture of sources and types of waste generated by farmers in an urban area and the management practices involved. Both studies are aimed at informing policy. Whereas the Nairobi study focused on the handling of nutrients by community-based organizations, this study of Nakuru focuses on how urban farming households handle waste, including that generated by livestock. Some of the health risks involved are examined in Chapter 12 of this book.

Nutrient Recovery from Solid Waste and Linkage to Urban and Peri-Urban Agriculture in Nairobi, Kenya

Community based composting practices were studied in Nairobi using a questionnaire, and the quality of composts produced characterised for nutrient and heavy metal contents. An inventory of the composting groups was made using existing databases. The quality of different manure types and their sources were also noted. The movement of Municipal Solid Waste (MSW) for composting and its outlets, as well as manures, were investigated through mapping of market and ecological chains. The study objectives aimed at documenting group dynamics in community based composting activities, quality of composts as influenced by different composting techniques and mapping of the movement of organic resources for soil fertility improvement.

Gender mainstreaming in organisational culture and agricultural research processes

Despite increased attention to gender issues in the international development arena since the rise of feminism in the 1970s, few agricultural research organisations have integrated gender in their problem diagnosis and technology development. Gender mainstreaming can significantly enhance the impact of research and technology development. Entrenching gender mainstreaming in organisations and their research agendas remains a challenge. To overcome it requires political will, accountability, a change in organisational culture, and technical capacity within an organisation. This article presents an experience of gender-mainstreaming practice in the institutional culture and agricultural research processes by Urban Harvest and the International Potato Centre (CIP).

Replication Data for: Evidence Based Forestry on socio-economic and environmental consequences of wood energy

This systematic map aims at providing a comprehensive approach to understanding the role and impacts of wood energy across all regions and aspects in Sub-Saharan Africa.

Commentary: building science and leadership skills in African women in agricultural research and development

Women make essential contributions to agriculture making up 43 and 50%, respectively, of the agricultural labour force globally and that in Sub-Saharan Africa (SSA). However, this contribution is not translated directly into actual control over any economic benefits in production (FAO, 2011). Of those women in the least developed countries who report being economically active, 79% report agriculture as their primary economic activity (FAOSTAT). In some regions within Africa, women do contribute over 60% of the total time spent in agricultural activities (FAOSTAT, 2009). A shortcoming of information on women’s share of the agricultural labour is that the data available do not account for differences in number of hours worked. If men who are identified as part of the ‘economically active population in agriculture’ provide fewer hours of agricultural labour than women in the same sector, we could underestimate the importance of women. For example, some literature suggests that men in Africa work fewer hours than women, across all activities (Blackden and Wodon, 2006). Compared with their male counterparts women operate smaller farms, keep fewer livestock typically of smaller breeds and earn less from the livestock they own. They have less education and less access to agricultural information and extension services, use less credit and other financial services, and are much less likely to purchase inputs such as fertilizers, improved seeds and mechanical equipment (FAO, 2011). Alderman et al. (1996) estimated that reducing inequalities in human capital, physical capital and current inputs between male and female farmers in SSA could potentially increase agricultural productivity by 10–20%. And for future agricultural research to produce meaningful changes, the needs, preferences, and constraints and differential roles of female farmers and women engaged in agricultural production must be recognized (Meinzen-Dick et al., 2010). In order to improve women’s lives, for example, through the achievement of equality between women and men as partners and beneficiaries of development, financial support is required, a need that has been well articulated by the recently established UN Women (Guardian News and Media Limited, 2011). Failure to recognize the roles, differences and inequities between men and women poses a serious limitation to the effectiveness of the agricultural development agenda (World Bank et al., 2009). In examining gendered patterns of extension, it is important to consider who delivers extension services because female extension agents are more likely to reach female farmers, especially in highly sexsegregated societies (Meinzen-Dick et al., 2010). Although male researchers can address the needs of women farmers, the lack of gender balance among agricultural scientists diminishes the likelihood that the specific needs of rural women will be met appropriately (Meinzen-Dick et al., 2010). In SSA only one in four agricultural researchers are female (Beintema and Di