Toward Sustainable Agricultural Systems in the 21st Century (2010)

Chapter: 8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States

Previous Chapter: 7 Illustrative Case Studies
Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

8
Sustainable Agriculture in Sub-Saharan Africa: “Lessons Learned” from the United States

The world population is projected to increase to more than 9 billion people by 2050, mainly in developing countries. Thus, it is important to know whether any supportable conclusions or “lessons learned” about sustainable agriculture practices or principles are transferable from one region to another or from industrialized to developing countries. In particular, is it feasible to transfer technologies and practices effectively used in the United States to resource-poor farming systems in developing countries? An extensive literature on agricultural development and a myriad of discussions on challenges and potential solutions for agriculture in Africa exists. This chapter is not intended to provide an exhaustive review of that literature, but to limit the discussion to the key findings that emerged from this study and consider them in the context of sub-Saharan Africa. Further, the committee recognizes that numerous “prescriptive” technology-transfer efforts from North to South have often lacked success (as noted below); therefore, the committee’s approach to the issue of technology transfer is to draw principles and lessons from this study that could be applicable and adapted in a developing country context, rather than to identify specific technical “fixes.”

The first part of this chapter briefly summarizes the food and agricultural challenges in the developing world, and the current adoption of agricultural practices that can improve sustainability, with an emphasis on sub-Saharan Africa. It then draws upon the lessons learned in previous chapters and assesses whether the principles and practices for improving sustainability derived from U.S. agriculture are relevant and transferable to developing countries. Furthermore, the chapter relates this committee’s findings to recommendations made in a number of recent multistakeholder international reports that address the future of agriculture and sustainability in Africa.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

THE IMPORTANCE OF CONTEXT

Evolving Agriculture in Sub-Saharan Africa

Agriculture is critical for human welfare and economic growth in developing countries. More than 1 billion people in China and India live on small-scale farms. In sub-Saharan Africa, more than 750 million people who live in dire poverty (earning less than US$1 per day) rely on subsistence agriculture as their major source of food and income, and about two-thirds of the people depend on farming for their livelihood (FAO, 2006; Diao et al., 2007; Toenniessen et al., 2008; World Bank, 2008). Yet, compared to India, China, and South America, only sub-Saharan Africa continues to show a decline in food security and agricultural productivity per capita and an increase in undernourishment since 1990 (FAO, 2006). The contribution of agriculture to gross domestic production in African countries varies from 10 to 70 percent (Mendelsohn et al., 2000). In other words, local livelihood of some African countries depends on the agricultural sector.

In general, part of Africa’s poor agricultural performance (and the concomitant pervasive problems of hunger) can be attributed to a wide array of production-limiting constraints faced by resource-poor farmers that include: shrinking farm sizes and inequitable land-distribution patterns, depleted soils and limited use of fertilizer and soil amendments (either organic and inorganic), unreliable rainfall and lack of irrigation capacity, and limited access to improved varieties and seed distribution systems. Other underlying factors that often contribute to or aggravate those constraints include: poorly maintained roads and transportation systems, inefficient markets or lack of access to regional or international markets, lack of credit, labor availability and demands, unstable political systems, poor security, warfare, and underinvestment by national governments and other institutions in the physical, institutional, and human capital needed to support sustainable agricultural intensification (Diao et al., 2007). Challenges to agriculture in Africa are likely to be made more difficult by the effects of global climate change (NRC, 2008). Numerous scientists, international organizations, political bodies, and others have analyzed the complexities associated with the challenging agricultural situation in many parts of Africa; likewise, various organizations have made many efforts to resolve or mitigate agriculture-related problems and to alleviate hunger. A comprehensive review of that literature was beyond the scope of this committee; instead, this chapter provides a brief overview of the issues and highlights what lessons can be drawn from U.S. experiences that, in the committee’s opinion, have relevance to agricultural development in Africa.

Lessons Learned from the Green Revolution

In Asia and Latin America, the introduction of Green Revolution technologies began in the 1960s, including high-yielding varieties, inorganic fertilizers, modern pesticides, irrigation, agricultural machinery, supportive government policies, wide-scale training of scientists, establishment of the Consultative Group for International Agricultural Research (CGIAR) Centers, and massive funding for research and development (R&D). These technologies dramatically increased agricultural output, raised farm-level income, and reduced food costs for urban consumers in many countries. The impact has been profound—aggregate world food production grew by 145 percent (140 percent in Africa, nearly 200 percent in Latin America, and 280 percent in Asia). In comparison, and starting at much higher levels of productivity, modern agricultural practices during that time doubled food production in the United States and grew production by 68 percent in Western Europe (FAO,

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

2006; Pretty, 2008). There was also a dramatic, if often overlooked, rise in consumption of animal-origin food products in developing countries, mostly in Southeast Asia and China. On a quantity basis, the additional meat, milk, and fish consumed between 1971 and 1995 in developing countries was two-thirds as important as the increase in wheat, rice, and maize consumed (Delgado et al., 1999). The increases in food production outpaced population growth and greatly reduced the incidence of chronic famine and the threat of starvation in many areas of the world, even as global population grew from 3 billion to 6 billion during that time period.

The historic transformation of agriculture across the world was massive and unprecedented, but its impact was not universal. In certain regions of South Asia and sub-Saharan Africa, small-scale farmers did not adopt the suite of modern agricultural technologies needed to obtain the gains in productivity because the package of new technologies generally favored large farms that had access to irrigation, improved varieties, and inorganic fertilizers, which many small farms did not have, nor could afford. In addition, Green Revolution technologies worked best in large areas of uniform cropping and irrigated systems, such as the high-production rice and wheat systems in Asia, or in rain-fed environments where both climate and soil quality are favorable for crop growth , such as the wheat systems of northwest and central Europe and maize-based systems in North America (Cassman, 1999). In contrast, as discussed below, Africa’s highly diverse cropping systems are primarily rainfed, on poor soils, and inherently riskprone.

Where the Green Revolution was successful, other problems developed—loss of local crop genetic diversity; fertilizer and pesticide contamination of water systems; pesticide poisoning of agricultural workers, beneficial insects, and wildlife; depletion of ground water sources; large concentrations of animals in urban environments where the regulatory framework governing livestock production is weak; degradation of rural grazing areas; and the clearing of forests (Delgado et al., 1999; Pretty, 2008). These problems are not confined to developing countries, and, indeed, some might be more acute in the developed world than in developing countries.

The transfer of modern agricultural technologies in general from developed countries to small-scale poor farmers in developing countries, particularly in sub-Saharan Africa, has been ineffective for several reasons. First, African farmers produce a wide variety of crops using diverse farming systems across a range of agroecological zones. Second, they are largely dependent on rain-fed agriculture, and many areas have soils that are severely depleted of nutrients. External inputs are expensive, and high transportation costs and lack of infrastructure often inhibit access to outside resources and markets. Third, African farmers’ perspectives, knowledge, and cultures were not taken into consideration during the technology development process (InterAcademy Council, 2004). Consequently, many modern agricultural practices that were successful elsewhere were not applicable to the complex needs of resource-poor small farming systems (Sands, 1986; Ashby, 1987; Lado, 1998). Furthermore, many sub-Saharan African countries do not invest much into agricultural research and development (Morgan and Solarz, 1994), so that they lack the capacity to adapt modern agricultural practices to local conditions.

A Second Green Revolution

Many organizations and governments in Africa are calling for a second Green Revolution (InterAcademy Council, 2004; Toenniessen et al., 2008; African Green Revolution, 2009; IAASTD, 2009). Unlike the first one that largely bypassed Africa, some argue that a second Green Revolution should be based on technological developments and favorable policies

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

that respond to a diversity of local farming systems and bring a high level of nutritional self-sufficiency to a region where people in many countries suffer from undernourishment. Many believe, and experience suggests, that no “silver bullet” technology package will broadly apply across the region. Rather, a systems approach is needed with research grounded in local contexts to develop locally appropriate technological and ecological solutions (InterAcademy Council, 2004).

According to several recent studies that document practical experiences of sustain able agriculture programs in developing countries, biological and ecologically based approaches, practices, and principles have resulted in improved production and positive economic outcomes, while also making more efficient use of natural resources (Pretty et al., 2006; Pretty, 2008). Similarly, a number of multistakeholder reports (InterAcademy Council, 2004; NRC, 2008; IAASTD, 2009) state that high priority should be given to developing technologies that focus on integrating biological and ecological processes (such as nutrient cycling, nitrogen fixation, soil regeneration, and biodiversity) into the production processes. That way, use of nonrenewable inputs, which can make farmers more vulnerable to input cost fluctuations, can be kept to a minimum and used judiciously. Further, productive use of the knowledge and skills of farmers’ and other people’s collective capacities to work together to solve common problems is important (Pretty, 2008). The idea of agricultural sustainability does not mean ruling out technologies or practices on ideological grounds if they can improve productivity and do not significantly affect the other objectives of sustainability (for example, cause undue harm to the environment or increase farmers’ vulnerability to risk). For example, integrated soil fertility management can benefit from the judicious use of inorganic fertilizer combined with organic fertilizers—a highly synergistic combination because organic matter increases the water-holding capacity of soils and increases the efficiency of fertilizer use by crops (Evanylo et al., 2008; Toenniessen et al., 2008). Yet, small farming systems are vulnerable to sudden cost increases or shortages if they become too reliant on external inputs, as observed in 2007 when oil and fertilizer prices reached record highs, and previously when governments eliminated subsidies on agrochemicals as part of structural adjustment programs (Denning et al., 2009).

Although there have been successful programs in the development and adoption of innovative sustainable approaches in many resource-poor contexts, barriers to more widespread implementation or change persist. One obstacle to launching a large-scale second Green Revolution is the decline of the CGIAR Centers and the pressure they face to focus on scientific or technological solutions which could be difficult to adopt across diffferent natural resource, economic, and political environments, rather than contextual systems solutions. That is in part because of severe budget cuts and decreasing support to other development programs and nongovernmental organizations such as CARE, World Neighbors, Winrock International, Heifer International, Rodale, and local institutions dedicated to developing innovative approaches in agriculture and natural resource management. In addition, a new Green Revolution would require additional support for local research and education institutions that can respond to needs of the small farming systems across the developing world (as discussed below). A second Green Revolution is unlikely without substantial funding from the international donor community, a commitment of resources, and favorable policies that reach out directly to the poor and build human capital at national levels.

LONG-TERM EVOLUTION TOWARD SUSTAINABILITY IN SUB-SAHARAN AFRICA

The challenge for Africa is the sustainable intensification of agriculture, that is, increased production per unit of land. In addition, some argue that the amount of land in agriculture

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

in some regions of Africa can potentially be expanded (FAO, 2009a). Projections indicate that a number of African countries could make much progress toward poverty reduction and food and nutrition security over the next 15–20 years by targeting policies and investment strategies that raise average crop yields by 50 percent, increase livestock numbers by 50 percent, and accelerate overall gross domestic product growth rates to 6.5–8.0 percent and the agricultural sector growth rate to 6 percent. Several experts agree that to achieve such a level of growth would require a commitment among African governments to reallocate up to 10 percent of their national budgets to agriculture, up from an average of 5 percent over the past decade continent-wide and only 4 percent in sub-Saharan Africa (African Union Report, 2008; World Bank, 2008). Although the growth performance implied above is high by historical standards, it is within the range of recent economy-wide and agricultural growth rates observed across Africa since the late 1990s (Runge et al., 2004; African Union Report, 2008; World Bank, 2008). Recent data also show that even agricultural production in sub-Saharan Africa grew at a rate of 3.5 percent in 2008 (FAO, 2009a). The Comprehensive Africa Agriculture Development Programme (CAADP) and the Sirte Declaration on Agriculture and Water are at the heart of efforts by African governments under the African Union to accelerate growth and eliminate poverty and hunger. The main goal of CAADP is to help African countries to reach a higher path of economic growth through agricultural-led development that eliminates hunger, reduces poverty and food insecurity, and enables expansion of exports. As a program of the African Union, it emanates from and is fully owned and led by African governments (African Union Report, 2008).

CONSIDERATIONS OF U.S. “LESSONS” LEARNED

Transferability of Agricultural Practices for Improving Sustainability

A large number of scientific-based issues relating to agricultural sustainability have been discussed throughout this report. Most, if not all, of the findings could be argued to have relevance to nearly every country. However, the specific methods chosen and priorities for their use in Africa need to be determined primarily by local and regional contexts and needs, as well as costs, potential and timing for impact, national R&D capacity, and the ability to attract resources from development assistance agencies.

The committee recognizes that many of the findings and conclusions in this report concur with recommendations made in recent reports that include Realizing the Promise and Potential of African Agriculture (InterAcademy Council, 2004); Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia (NRC, 2008); Science and Technology for Development (IAASTD, 2009); and The World Report 2008, Agriculture for Development (World Bank, 2008). The commonalities among reports demonstrate that some sustainability principles and approaches are widely relevant, although, as discussed below, the details of implementation on the ground will be highly context specific. A series of science and technology recommendations to increase food security in Africa recommended by the InterAcademy Council (see Box 8-1) illustrate many of the commonalities in sustainability principles and the specific needs for the African context.

Further discussion and explanation of the recommendations in Box 8-1 can be found in the relevant sections below. The International Assessment of Agricultural Knowledge, Science and Technology for Development (IAASTD) reached many similar conclusions in its 2009 report (IAASTD, 2009). IAASTD is a multidisciplinary and multistakeholder effort that was initiated by the World Bank and the Food and Agriculture Organization of the United Nations in 2002. It evaluates the relevance, quality, and effectiveness of agri-

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

BOX 8-1

Science and Technology Recommendations to Increase Food Security in Africa Proposed by the InterAcademy Council of the United Nations (2004)

Near-Term Impact:

  • Adopt a production ecological approach with a primary focus on identified continental priority farming systems.

  • Pursue a strategy of integrated sustainable intensification.

  • Use a blend of knowledge-intensive and technology-driven approaches that integrate with indigenous knowledge.

  • Adopt a market-led productivity improvement strategy to strengthen the competitive ability of smallholder farmers.

  • Recognize the potential of rain-fed agriculture and accord it priority.

  • Reduce land degradation and replenish soil fertility.

  • Explore higher-scale integrated catchment strategies for natural resource management.

  • Enhance the use of mechanical power.

  • Embrace information and communication technology at all levels.

Intermediate-Term Impact:

  • Bridge the genetic divide.

  • Improve the coping strategies of farmers in response to environmental variability and climate change.

Long-Term Impact:

  • Promote the conservation and the sustainable and equitable use of biodiversity management.

cultural knowledge, science, and technology on hunger, poverty, nutrition, human health, and environmental and social sustainability, and the effectiveness of public and private sector policies and institutional arrangements that focus on smallholder agriculturists. The assessment addressed how agricultural knowledge, science, and technology could reduce hunger and poverty, improve rural livelihoods, and facilitate equitable environmentally, socially, and economically sustainable development. It also proposed that new priorities and shifts in agricultural knowledge, science, and technology recognize and give increased importance to the multifunctionality of agriculture, which encompasses multi-output activity producing not only commodities (food, feed, fibers, biofuels, medical products, and ornamentals), but also noncommodity outputs such as environmental services, landscape amenities, and cultural heritages. It proposed, as well, that new institutional arrangements and policy changes be directed primarily at resource-poor farmers, women, and ethnic minorities. Fifty-eight countries approved the executive summary of the IAASTD synthesis report, but three countries (Australia, United States, and Canada) had reservations about some parts of the report, particularly the findings concerning the role of genetically engineered (GE) crops in sustainable agriculture development. The use of GE crops was not rejected in principle; rather, the report found that GE crops were appropriate in some contexts, but as of yet, the potential of GE crops to serve the needs of resource-poor farmers remains unfulfilled. There is no conclusive evidence so far that GE crops offer solutions to the broader socioeconomic dilemmas faced by developing countries (Kiers et al., 2008).

The next section first discusses the relevance of conclusions from earlier chapters of this report at the whole-system level, and then discusses component technologies that could be

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

appropriate for the African context. The committee identified 12 major areas of agricultural science and technology, agricultural-supporting infrastructure, policy, and development process that are critical for the United States and have relevance, with appropriate adaptation, to African sustainable agricultural development.

  1. Sustainability is ultimately defined by the goals and objectives determined through an inherently political process and are highly context dependent.

    Sustainability is a process of moving toward identified goals, but progress can be made in many different ways or by using a combination of different strategies. The four sustainability goals1 outlined in Chapter 1 of this report are sufficiently broad to apply to the African context, although specific objectives within each goal, and the priority given to each objective, need to be determined through a political process (informed by scientific principles and knowledge) by people in the different regions of Africa. The importance of reflecting the priorities of African countries is strongly stated in the United Nation’s InterAcademy report (InterAcademy Council, 2004) and in the report from the African Union (African Union Report, 2008). The need for African ownership of development efforts to improve food production and sustainability will require building a stronger indigenous research and education capacity. Increasing the involvement of farmers, especially women farmers, in research, policy discussions, and activities is critical to pursue appropriate goals and strategies (IAASTD, 2009).

    Throughout this report, the importance of understanding the biophysical, socioeconomic, and political context within which a farming system operates when seeking strategies to increase productivity sustainably has been discussed at length. That understanding is critical in a highly diverse continent such as Africa. The strategies for achieving different sustainability objectives will be specific to particular regions of the continent, and as such will require creation of interdisciplinary research and education institutions at multiple levels, from regional and national to local, with effective mechanisms to exchange information and knowledge among them.

  2. Sustainable systems need to be productive, efficient in resource use, and robust.

    System attributes that are important for sustainability—productivity, system efficiency, and robustness (that is, have a combination of resilience, resistance, and adaptability to stress and changing conditions; see Chapter 1)—are emphasized in this report. In other words, a system needs to have the ability to continue meeting identified goals in the face of unpredictable weather and fluctuations in cost and availability of inputs to be sustainable (see Chapter 1). These points are also made in other reports (InterAcademy Council, 2004; NRC, 2008; World Bank, 2008; IAASTD, 2009) that argue for specifically focusing on strategies and technologies to improve productivity and increase efficient use of resources, most notably water, and to address the ability to adapt to climate change.

    The importance of building resilient and adaptable systems cannot be overstated. Predictions are that under climate change, there will be higher rainfall variability and uncertainty than at present, especially in arid and semiarid areas; extreme events like floods and droughts will become more frequent; and temperatures will increase in sub-Saharan Africa (NRC, 2008; IAASTD, 2009). Given that only 4 percent of agricultural land in sub-

1

Satisfy human food, feed, and fiber needs, and contribute to biofuel needs; enhance environmental quality and the resource base; sustain the economic viability of agriculture; enhance the quality of life for farmers, farm workers, and society as a whole.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

Saharan Africa is irrigated, unpredictable weather patterns will greatly affect the majority of rain-fed systems. As discussed in the report Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia (NRC, 2008), developing strategies to alleviate both the agroecological and economic impacts of climate change will be necessary. Farmers will need tools to have the flexibility to adapt to changing conditions. Adapting to changing climate conditions will involve agroecosystem design, such as use of multiple cropping instead of monoculture, and use of varieties bred to incorporate adaptation to multiple stresses such as drought, high temperatures and flooding, and landscape diversification. Systems that take advantage of natural processes, complementarities, and efficiencies can often reduce the need for external inputs, and thus reduce vulnerability to changes in input availability and cost. A diversity of products and markets would also help buffer farmers from fluctuating weather and prices, and reduce the risk of food shortage in bad years.

In addition, strengthening social and institutional networks (Turner et al., 2003; Nelson et al., 2007) and building appropriate infrastructure can also help buffer against fluctuating conditions. High capital investment (especially in infrastructure) would need, however, to be well planned, cost effective, and seek to improve both the productivity and adaptive capacity of farmers in the region.

  1. Criteria and indicators are needed to assess progress toward achieving sustainability goals.

    In addition to goals and objectives, criteria for assessment and well-designed indicators of progress toward sustainability are needed at each level from the global to regional, national, and community levels. Much attention is given to that notion in the Millennium Report, which discusses goals and indicators from the level of the Millennium Development Goals (United Nations, 2008) downward to goals for nations and for community-level civil society groups. In defining indicators of sustainability, the development and testing process has to be decentralized at the national, state, and community levels if the indicators are to be relevant and have broad ownership.

    “Sustainability” has particular priority objectives and time frames when very poor farmers are striving to move toward greater productivity, quality of life, and resource stabilization, which indicators need to reflect. For example, ensuring adequate productivity for short-term survival is critical, as is sufficient system robustness to prevent yields falling below critical levels over the longer term. In addition, resource stabilization, such as building soil organic matter and inherent fertility, is a long-term but critical component. “Improved” systems need to address all these priorities simultaneously to effectively move toward sustainability, and therefore need to be evaluated against appropriate indicators for each component (see Chapter 1).

    Well-constructed indicators can be highly relevant as guides for agricultural development agencies and groups at all levels. The process for their identification could be informal, but the indicators and the assumptions upon which they are based would have to be made clear by all development groups as interventions are made.

  2. Priority should be given to an integrated systems approach to R&D that encompasses ecological, technological, and socioeconomic elements.

    If the four sustainability goals are to be addressed, then efforts to develop new technologies need to use integrated systems approaches to assess performance characteristics and the agroecological, environmental, and socioeconomic drivers operating in the farming system in question. Integrated studies of performance and the various drivers are particularly important to identify synergies among different management practices or barriers to

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

adoption of different practices. The need for a systems approach is a key recommendation in a number of recent reports (InterAcademy Council, 2004; NRC, 2008; World Bank, 2008; IAASTD, 2009). That need is strongly echoed by Pretty et al. (2006), who identified many synergies when multiple practices were used together in a systems approach. Programs, thus, need to avoid reductionist approaches that have a single focus on particular technologies and “interventions” that are seen as silver bullets or panaceas.

To date, Pretty et al. (2006) have conducted the largest study examining systems that have adopted practices aimed to move toward improved sustainability and production in developing countries. Their findings illustrate the importance of taking an integrated systems view of agriculture. They analyzed more than 286 agricultural projects covering 37 million hectares in 57 developing countries that used a variety of what they called “sustainable farming technologies and practices.” Their objective was to determine which low-cost and locally available technologies and inputs increased total food crop productivity, and the impact of those methods on water use efficiency, carbon sequestration, and pesticide use. They found that some 12.6 million farmers on the 37 million hectares were engaged in transitions toward improved agricultural sustainability. When various agricultural practices were adopted and certain resources were available, average crop yields and available food, over a variety of systems and crops, increased by an average of 79 percent. The practices included effective use of locally available natural resources (for example, water harvesting, conservation tillage practices, composting, use of livestock manures, and irrigation scheduling and management); intensification of production from microenvironments in farm systems (for example, gardens, orchards, and ponds); managing diversity by adding new regenerative components (for example, cover crops and green manures); and efficient use of nonrenewable inputs and external technologies (for example, resistant crop varieties and livestock breeds, new seed, low-dose and non-toxic pesticide sprays, and machinery). In addition, developing farmer and community participatory processes; building human capital through continuous education; and improving access to markets, infrastructure, and affordable finance (for example, credit, grants, and subsidies) were also found to be critical. Therefore, supportive government policies are important.

Targeting investments in systems research for the highest-priority production system types within Africa, and locating research institutions in areas where they can represent as large an area of a similar production system as possible, will be important. The United Nations’ InterAcademy Council identified four priority systems based on the criteria of the number of malnourished children who depend on the system and the potential for significant improvement in productivity: maize-mixed system, based primarily on maize, cotton, cattle, goats, poultry, and off-farm work; cereal-root crop-mixed system, based primarily on maize, sorghum, millet, cassava, yams, legumes, and cattle; irrigated system, based primarily on rice, cotton, vegetables, rain-fed crops, cattle, and poultry; and tree crop-based system, based primarily on cocoa, coffee, oil palm, rubber, yams, maize, and off-farm work.

Systems research suitable for the African context needs to be locally grounded, with researchers actively engaged with farmers in the area to ensure the appropriateness of the study (InterAcademy Council, 2004). As discussed in Chapter 5, systems experiments can be established at field stations or in farmers’ fields to compare management approaches. Such studies in the United States have produced a lot of useful information (see examples in Chapters 3 and 5). Studies comparing integrative practices that are well defined have been particularly useful. Examples are tillage comparisons, cover crop integration into rotations, integrated pest management for particular crops such as tree fruit or certain field crops, and, in some instances, well-defined systems approaches such as organic production. Many of these studies compared specific integrative practices within a whole-farm context to de-

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

fine and measure appropriate interactions (Drinkwater, 2002; Snapp and Pound, 2008). The on-farm systems studies are often conducted under experimental management by farmers and last for 5–10 years to measure intermediate-term effects. The studies require considerable farmer interest and support (Carter et al., 2004). In developing countries where farms are resource poor, such lengthy on-farm comparison studies might be too costly and take up too much land. Systems experiments might be more suited for well-located field stations than for farms, as long as farmers are closely involved and research institutions are given sufficient and secure funding to carry out multiyear trials.

Other kinds of on-farm research also can be used and can enable farmers to directly observe how different management or technological approaches perform and to develop their own adaptations on their farms to the systems studied elsewhere (Snapp and Pound, 2008). Instead of having replicated studies on farms, an alternative and more feasible approach for farmers with limited landholdings can be to compare different practices, or suites of practices, once on each farm, and repeat the trial on multiple farms. The different farms are treated as replicates (see, for example, Snapp et al., 2002a).

Participatory on-farm research has ranged from trials designed and managed by researchers, but located in farmers’ fields, to farmer–researcher-designed and farmer-managed approaches (Snapp et al., 2002a; Snapp and Pound, 2008). The more involved the farmers are, the greater the exchange of information and mutual learning. One drawback of on-farm research is that it can be risky because the environment is less controlled, and farmers might have more pressing priorities than research.

A combination of approaches might provide the best information, with on-station experiments determining the potential for different approaches and on-farm trials providing information on performance and challenges in the real world. One example of a combined approach is the “mother and baby” trial design of Snapp (1999, 2002), where a series of “mother” trials are conducted at experiment stations, and then selected systems are tested in a series of “baby” trials in multiple farms and villages in the region. Snapp et al. (2002b) conducted their on-farm trials in different landscape positions (slopes, well-drained gentle slopes, and flood-prone valley floors) to evaluate the relative performance of different systems based on legumes and fertilizers in each landscape type. Using that design, agroecological and production data were collected, including spatial and temporal variability in system performance, and information on farmer preferences and assessments of the systems were tested (Snapp et al., 2002b).

Another successful example of a combined approach is the integrated natural resource management program in West Africa, where a number of international institutions have worked together with farmers to increase productivity in mixed crop and livestock systems. The first step was to prioritize the main constraints to production, then draw upon the “best-bet” options that have emerged through research experiments and have farmers test them against their own practices. Assessments of productivity, nutrient cycling, economic and social benefits and farmers’ perceptions were then made (Snapp and Pound, 2008).

  1. Farmer participation in research is critically important to ensure research is locally relevant.

    Agricultural research that is locally relevant is necessary and can be achieved by consulting with and actively involving clients, notably farmers. Earlier paradigms that tried to fit farmers into the typically linear top-down structures of research–development–extension worked well for major cash crops, but had little success with small-scale diversified farms (IAASTD, 2009). Potential ways to address that problem include involving farmers in setting research priorities, increasing collaboration with social scientists, and increasing

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

participatory and interdisciplinary work at the core research institutions (IAASTD, 2009). Chapter 6 discussed some examples of successful participatory agriculture programs for improving sustainability in the United States that demonstrate the value of linking re searchers with farmers. Such approaches have contributed to moving farms toward meeting multiple sustainability goals by working with a systems perspective (see Warner, 2006, for examples). The argument for farmer participation has been made for many years in the context of agricultural development, and such approaches have been used in different contexts (Pretty et al., 2006; Snapp and Pound, 2008). Farmer involvement is a central theme in the United Nations’ InterAcademy Council report, which states the “knowledge intensive and technology driven approaches must be integrated with indigenous knowledge and farmers needs and demands to ensure appropriateness and adoption of innovation” (InterAcademy Council, 2004). Similarly, the National Research Council argued that a locally trained workforce is imperative for development and adoption of new technologies (NRC, 2008). The IAASTD report points out that innovation is more than invention. Successful innovation is based not only on technological performance, but also on how the technology builds knowledge, networks, and capacity.

Many grant programs and development institutions require participatory approaches in which farmers or groups of producers are actively engaged in the R&D process to ensure long-term success of any initiative for change and improvement. Those approaches have been extended from project-specific efforts of participatory research and appraisal, participatory learning and action, and the Farmer Field Schools of the Food and Agriculture Organization (FAO) to engaging farmers in policy-related efforts or organizational initiatives to achieve broader institutional and policy changes that can contribute to improving sustainability at a regional level (Farrington and Martin, 1998). One of the largest participatory programs, FAO’s Farmer Field Schools, has reached millions of farmers in many different countries with training in integrated pest management (Pontius et al., 2002). Many regard the Farmer Field Schools as a general success (Pontius et al., 2002; Pretty et al., 2006; van den Berg and Jiggins, 2007), but some observers see limitations (Feder et al., 2004a,b). Another example of a successful participatory approach is the Sustainable Livelihoods Analysis applied as part of an FAO project in Afghanistan (FAO Project: GCP/AFG/029/UK) (Snapp and Pound, 2008). Further, evidence from East Africa suggests that innovative participatory approaches to agricultural development, such as farmer research groups, are more successful in reaching women farmers (who represent the majority of farm workers in sub-Saharan Africa) than traditional extension activities (IAASTD, 2009).

As part of a consultation meeting to prepare for the Global Conference on Agricultural Research for Development (GCARD)2 to be held in France in 2010, the African Farmers Organization released a declaration that recognizes the importance of agricultural research and development for farmers in Africa, and reaffirms the central position of farmers and farmer organizations in making research successful (African Farmers Organization, 2009). This organization comprises five regional farmer federations that, in turn, represent alliances of national farmer organizations from countries within each region. However, despite the advances that have been made, the organization also highlighted some continuing concerns (African Farmers Organization, 2009), including the following:

2

GCARD is organized by the Global Forum on Agricultural Research (GFAR) in collaboration with the Consortium and Independent Science and Partnership Council (now being formed) of the Consultative Group on International Agricultural Research (CGIAR).

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.
  • “The weak engagement of farmers and farmer organizations with research institutions in terms of setting the research for development agenda in Africa.

  • The challenges that farmer organizations are facing in identifying, collecting, analyzing, and articulating the research needs of poor farmers.

  • The weakness of the extension/agricultural advisory services, leading to failure of research findings reaching the farmers.

  • The diminished involvement of farmers in measurements of impact and use of tools to evaluate successes or failures of research on improving rural livelihoods.”

Those concerns would have to be addressed in future research and education efforts because they identify critical issues in terms of process, resource allocation, and investment.

  1. It is critically important to consider the social, market, and policy environments within which farming systems are embedded.

    Farms and the technologies and practices used in their management are nested in changing and fluctuating social, economic, and political environments. This report stresses the importance of markets, policies, knowledge institutions, and local resource conditions in shaping the ability of farmers to move toward sustainability goals. (See Chapters 4 and 6.) Those contextual factors operate at the level of households, communities, landscapes, nations, and global markets. The lesson about fluctuating environments applies equally well to Africa. For example, recent fluctuations in global energy and corn prices caused considerable hardship in Africa, and changing national policies with respect to subsidizing farm inputs have dramatic implications for options available to resource-poor farmers.

    IAASTD (2009) recognized that to improve agricultural productivity, economic security, environmental quality, and social welfare simultaneously requires more than traditional agricultural production science and technology development. Rather, movement toward greater sustainability requires careful consideration of how the viability of farming practices might be affected by differential patterns of access by farmers to land, inputs, and irrigation water; the specific goals and objectives of farm operator households; the structure of agricultural input and output markets; and the prevailing policy environment. An integrated approach also requires attention to the multiple functions of agriculture beyond mere food production, such as the contribution of agriculture to improvement of livelihoods and the maintenance of social and cultural traditions, provision of ecological services, and conservation of natural resources. The importance of considering the social, market, institutional, and policy contexts are discussed further below.

    1. Social Environments

      As in the United States, the farm sector in Africa is extremely diverse, ranging from large-scale modern commercial farms to subsistence production on extremely small parcels. Unlike in the United States, however, much of the African population relies on small-scale commercial or subsistence farming to survive. Therefore, efforts to improve the well-being of the smaller producers are seen as a critical component to improve social and economic well-being on the continent. Programs such as the National Fadama Development Project in Nigeria supports smallholder farmers by helping them increase agricultural productivity, access infrastructure, and add value to their products (National Fadama Development Project, 2010). The First National Fadama Development Project (Fadama I) was designed to promote simple and low-cost improved irrigation technology. Adoption of low-cost irrigation technology enabled farmers to increase production. Fadama II, a follow-up to the

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.
  1. first phase, aims to increase the incomes of the Fadama users through expansion of farm and nonfarm activities with high value-added output. It includes a participatory approach in which Fadama users will collectively identify their development priorities and agree on their investment activities. Other distinct strategies to develop innovative production techniques might be necessary to meet the needs of farmers with differential access to land, labor, machinery, inputs, and markets.

    Attention to social dimensions of farming over the past two decades also has led to greater appreciation of the critical role of women in African agriculture. Women account for about 70 percent of agricultural workers and 80 percent of food processors in sub-Saharan Africa. It is imperative, therefore, that women have significantly increased representation in research, extension, and policy making, and equitable access to education, credit, and secure land tenure (IAASTD, 2009). The training of women as researchers and extension agents would greatly facilitate the process of reaching women farmers and understanding their needs and limitations when looking to introduce new management technologies and approaches.

  2. Market Advances and Policy

    The general consensus is that for small farmers in rural Africa to improve their livelihoods, they will need greater access to markets and that economic policy needs to be conducive to their entry. For example, the United Nations’ InterAcademy report (2004, p.xxvii) states that “a vibrant market economy and effective economic policies are essential in making poor families income and food secure.” The IAASTD report (2009) goes as far as to state that “the lack of connection between Sub-Saharan African farmers and the market has seen agriculture remain rudimentary, unprofitable and unresponsive to market demand.”

    At the same time, the structure of new markets for farm commodities in Africa will affect which producers will benefit most from new opportunities. As Chapter 6 indicated, nearly all farmers in the United States depend on being able to market their products, but different types of markets have produced different opportunities and constraints to their abilities to use practices that enhance sustainability. Conventional global agricultural commodity markets, for example, principally reward farmers who can produce large volumes of specialized commodities at the least cost. Farmers who seek to diversify their operations, minimize their environmental impacts, enhance social acceptability, or address farm labor or animal welfare concerns might find themselves at a competitive disadvantage if they rely on traditional marketing outlets. At the same time, emerging marketing alternatives, including value-trait and short-supply chain markets, can provide new incentives that could encourage farming practices that advance other aspects of sustainability.

    Importantly, developing new markets for farm products often requires explicit public and private efforts to create the infrastructure and reduce transaction costs, particularly for alternative markets that operate outside the global agrifood system. The committee has argued that the lack of an appropriate agricultural infrastructure can constrain the ability of farmers to adopt new commodities or marketing approaches on local farms. Efforts to increase sustainable farming systems may need to focus as much on infrastructure and market development as on production techniques or practices.

    This is equally true for African farmers, where local and regional agricultural and rural infrastructure and market development are typically very poor, but urban areas and commercial farms are increasingly being integrated into global agrifood retailing chains (Reardon et al., 2009). Growing commercial markets have sometimes provided important benefits to smallholder farmers in Africa (Minten et al., 2009), but often disadvantage resource-poor farmers relative to larger operations (Neven et al., 2009).

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

Unlike the United States, postharvest storage and handling facilities are poorly developed in much of Africa, but will be critical if farmers are to access markets other than those available locally. Investment in storage infrastructure and rural roads is needed for products to meet quality standards and make international and regional markets accessible to small farmers. To enter international markets, the issue of food safety and food-safety standards will need to be addressed, especially for fresh produce (as discussed for the United States in Chapter 4).

The United Nations’ InterAcademy Council report (2004) also makes the point that information and communications technology can play a critical role in market development by giving farmers better access to markets and information on demand (for example, prices). Those technologies could also enable farmers to participate more actively in policy discussions and in setting R&D priorities.

Market diversification is an important strategy for risk management and economic success. (See Chapters 4 and 6.) The ability to access a range of markets from local to regional and international can improve market diversification. As in the United States, diversification options could include seeking value-trait markets and the creation of value-added products. One example of African farmers accessing a value-trait market is organic cotton. Kenya and Tanzania have the most developed markets in Africa, but countries such as Burkina Faso and Benin have also entered the market (Dowd, 2008; UNEP-UNCTAD, 2008). The market demand is expected to exceed production in the near future and make organic cotton a promising avenue for African farmers provided that barriers and challenges to production and market access can be overcome (Dowd, 2008). Meanwhile, studies of global systems to certify and source organic, fair trade, and other value-trait foods from developing countries have discovered a number of potentially adverse impacts on smaller and less sophisticated producers, who may be less prepared to comply with mandatory paperwork and could be forced to forgo the opportunities (Marsden and Murdoch, 2006). It is predicted, however, that market demand for organic cotton will exceed production in the near future, making it a promising avenue for African farmers provided that barriers and challenges to production and market access can be overcome (Dowd, 2008). The adoption of certified-organic practices in general has expanded substantially in developing countries, and could provide particularly beneficial income opportunities for farmers who export their produce, particularly if they are organized that share the paperwork burden. Nonetheless, adoption of certified-organic practices poses significant administrative challenges, as mentioned previously, and significant production challenges in areas where soils are extremely degraded or in humid areas where weeds are prolific and expensive to control using only organic methods. Certified-organic production still represents a small proportion of overall agricultural production in the developing world, but could offer significant potential for the future, particularly if supported by further research, investment, education, and adaptation for local contexts.

The committee also discussed how the policy environment has a major impact on farm economics. (See Chapter 6.) Environmental and conservation policies might require or encourage the adoption of some best management practices, whereas others, such as commodity program payments, might discourage the use of complex rotations; similarly, the availability of crop insurance might encourage high-risk production systems. The policy context is equally important for affecting agriculture in Africa. For example, subsidies for agricultural inputs such as fertilizer have had a major impact on accessibility to small farmers and their subsequent levels of production. One example is Malawi, where fertilizers and other agricultural inputs were heavily subsidized prior to structural adjustment. When

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

the subsidies were removed, production declined. Because of low productivity, subsidies have been reintroduced in recent years to avoid widespread hunger (Denning et al., 2009). Simply subsidizing fertilizer, however, cannot be sustained over a long term (as discussed below in the technologies section), and incentives for using other soil improvement and water-efficient approaches will be needed if they are not provided by markets. It is also critical to establish means for African farmers, irrespective of farm size, to obtain loans at reasonable terms of repayment.

Payments for environmental services (PES) can be an option for African agriculture to directly reward management practices that contribute to maintaining and enhancing environmental services (for example, biodiversity conservation, carbon sequestration, water quality and availability, and land rehabilitation and nutrient cycling) and for small-scale farmers to be involved in voluntary markets for carbon (IAASTD, 2009). The challenges to instigating such payment systems, however, are discussed in Chapter 6, and it should be noted that in the United States, the use of PES has been limited. PES requires substantial record keeping that, for smallholders, is best done through farmers’ organizations and nongovernmental organizations.

World trade is highly competitive, and removal of formal and informal barriers to trade, both interregional and international, will be critical to expanding market opportunities (InterAcademy Council, 2004). It is important to note that when the United States uses agricultural export subsidies, imposes import tariffs or quotas, or provides subsidies for production of U.S. commodities, non-U.S. agricultural producers are at a disadvantage. Even the delivery of U.S aid to countries, if the aid comes in the form of U.S. agricultural products, can depress local country prices and thereby reduce the income of local farmers.

  1. A major investment in institution-building will be required to advance African agriculture.

    The lack of well-funded and well-equipped research and education institutions is a serious problem facing much of Africa. The lack of infrastructure is related to a lack of government investment. For example, investment in agricultural research tripled in China and India over the past 20 years, but it only increased by one-fifth in sub-Saharan Africa overall and actually declined in about half of the countries. The lack of strong indigenous research and education systems is especially problematic in Africa because the agroecological complexity of its farming systems means that they are less able to benefit from international technology transfers (World Bank, 2008). Furthermore, many of the most talented research scientists seek to work in other countries with better facilities and funding (InterAcademy Council, 2004).

    Efforts are currently underway to try to increase public investment in agriculture R&D to 10 percent of gross domestic production (an increase from 4 to 5 percent in Africa) in the near future, which represents a critical juncture for planning how to best invest that money (African Union Report, 2008). Investment in research and education institutions that promote systems approaches to improving sustainability and productivity is critical (InterAcademy Council, 2004; NRC, 2008; IAASTD, 2009). In Chapter 6, the roles of government funding, research institutions, and university programs in U.S. agricultural R&D were discussed at length, with the following points emerging: public sector funding is critical for addressing nonproduction efficiency questions such as the environment and resource management, poverty alleviation, and others; shifting the direction of longstanding programs into more holistic systems thinking and approaches has been difficult but necessary for the

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

development of new programs to advance those research efforts; and active involvement of farmers and farmer organizations in research can be effective in influencing how agriculture is conducted. These points are important lessons for Africa. To move forward on meeting multiple sustainability goals simultaneously, it will be imperative that integrated systems approaches, interdisciplinary thinking, and participatory process be an integral part of both newly created institutions and efforts to rebuild and refocus existing programs.

Education in general is a critical element in improving agriculture in Africa, both for the general population and for research and extension personnel. Indeed, the United Nations’ InterAcademy report (2004) suggested that a major change in curricula at universities and other higher education institutions is needed. The suggestion is to build curricula that focus on production, ecological, and multidisciplinary approaches and that expose students to farmers and their knowledge and issues. In that way, researchers and extension agents will be well versed in the socioeconomic and policy contexts in which agriculture is operating.

A number of short- and long-term goals for institutional development in Africa are listed in the InterAcademy report (see Box 8-2). Those goals emphasize a multilevel approach with the development of strong local, national, regional, and international research and education institutions. These institutions will need to be firmly embedded in interdisciplinary and systems thinking, the context within which farmers are operating, and be connected closely with the farming communities in the surrounding areas. In the United States, one mechanism to ensure farmer involvement has been to make it a requirement for research funding. For example, a number of U.S. Department of Agriculture competitive grants programs require researchers to explain how farmers are involved in the design, execution, and evaluation of projects when submitting proposals. Furthermore, modifying university curricula to train new researchers and extension agents to become well grounded in interdisciplinary knowledge and systems thinking will be critical.

BOX 8-2

Institution-Building Recommendations to Increase Food Security in Africa Proposed by the InterAcademy Council of the United Nations (2004)

Near-Term Impact:

  • Design and invest in national agricultural science systems that involve farmers in education, research, and extension.

  • Encourage institutions to articulate science and technology strategies and policies.

  • Increase support for agricultural R&D.

  • Provide sustainable funding for higher education in science and technology.

Intermediate-Term Impact:

  • Cultivate African Centers of Excellence.

  • Strengthen International Agriculture Research Centers.

  • Focus on retention of agricultural scientists by creating opportunities at well-resourced institutions.

Long-Term Impact:

  • Reform the university curriculum to stress both production and ecological and multidisciplinary approaches.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.
  1. Development and adoption of suitable technologies to address abiotic and resource constraints will be critical.

    Technology development will provide new tools and practices to increase agricultural production and achieve other sustainability goals at the same time. The NRC report Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia (2008) recommended 18 high-priority technologies as most likely to have a significant impact on agricultural productivity in the two regions. Many of the priority technologies listed in the 2008 NRC report coincide with practices and technologies discussed here. The technologies focus on natural resource management, improving genetics of crops and animals, overcoming biotic constraints, and energy production. Three similar types of technological improvements were thought to have played substantial roles in the field productivity increases observed by Pretty and colleagues in their study of 246 projects discussed earlier (Pretty et al., 2006): technologies that improve water-use efficiency in both dryland and irrigated farming; improve organic matter accumulation in soils and carbon sequestration; and manage pests, weeds, and diseases with an emphasis on in-field biodiversity and reduced pesticide use. Pretty et al. also noted that combinations of different improvements and practices showed the greatest positive effects. Some of the key technologies and management practices that the committee judges to contribute to the sustainable intensification of African agriculture are listed below.

  1. Management to Improve Soil Quality

    Chapter 3 discusses the central role of proper soil management and maintenance of good soil quality in improving agricultural sustainability. Soil quality encompasses a range of properties including nutrient cycling, disease and pest suppression, soil physical structure, water infiltration rate, and water-holding capacity. A key component of good soil quality is building and maintaining soil organic matter, which is particularly important for many of the poor fertility soils found in Africa where organic matter levels are low. Inputs of organic residues (such as animal manure, green manure, and crop residue) and reduced or no tillage are strategies known to increase soil organic matter. Prevention of soil loss in the surface layers, where the organic matter is generally highest, also is critical. Implementing such approaches as reduced tillage, use of organic matter inputs, and protection of the soil surface is a priority for agricultural development in Africa to reverse the serious problems of declining soil fertility and soil quality.

    A suite of practices referred to as “conservation agriculture” has been increasingly promoted and adopted in developing countries to improve soil organic matter levels and crop productivity. Conservation agriculture is similar to the move toward reduced or conservation tillage in the United States (Chapter 3). Conservation agriculture is characterized by three principles that are linked to each other in a mutually reinforcing manner. The three principles are continuous no or minimal mechanical soil disturbance (that is, direct sowing or broadcasting of crop seeds, and direct placing of planting material in the soil), permanent organic-matter soil cover (by crop residues and cover crops in particular), and diversified crop rotations in the case of annual crops or plant associations in case of perennial crops, including legumes (Meyer, 2009). Conservation agriculture has been successful in some areas, notably Brazil (European Technology Assessment Group, 2009), but it is not a simple technology package that can be applied across widely different areas. For example, applications in South America usually are based on highly mechanized farming systems where low-tillage planters are readily available and herbicide application technologies are accessible to farmers. In contrast, while conservation agriculture in South Asia uses herbicides, it is based on small-scale equipment or even planters who use draft animals. Conservation

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

agriculture is knowledge intensive, requires farmers to adapt planting methods to reduce or eliminate tillage, can be greatly enhanced with selective herbicide application, and requires farmers to finetune the application of the recommended technologies to their own specific situations (European Technology Assessment Group, 2009). Some argue that lack of adoption can be a problem particularly in Africa (Gowing and Palmer, 2008; Baudron et al., 2009). A comprehensive review of the scientific literature on conservation agriculture with relevance to Africa and to its benefits and adoption in the Americas (Giller et al., 2009) lists the many factors of water availability, soil type and condition, competing uses for crop residues, increased labor demand for weeding (or for use of herbicides), and lack of access to, and use of, external inputs as critical constraints to adoption of conservation agriculture in Africa. Clearly, more research is needed to determine if conservation agriculture can successfully be adapted for the challenging environments of Africa and help address soil degradation and fertility problems. A number of such research efforts are now underway (FAO, 2009b; Giller et al., 2009).

The NRC report (2008) identified a number of techniques for improving overall soil quality that could be applicable in Africa, and the key will be to identify which work best in different environmental and socioeconomic contexts. Techniques listed include: use of cover crops in rotations, applying manure, agroforestry, terracing, no-till or conservation tillage, crop residue retention, mulches for erosion control, controlled grazing, appropriate irrigation, and integrated fertility management (NRC, 2008). In addition, the report suggested exploring the potential of nanotechnology in the future, notably the application of zeolites that have specific ion exchange and reversible dehydration properties and could function as slow-release fertilizers and aid in water retention. Similarly, rhizosphere manipulation could be useful, as discussed in Chapter 3 of this report. In particular, the NRC report (2008) identified long-term potential for breeding plants with improved root structure, encouraging populations of plant growth–promoting bacteria either through soil management or by adding them as a soil amendment, and improving soil suppressiveness to disease.

  1. Integrated Fertility Management

    Fertilizer use in Africa is low compared to elsewhere. The average application in Africa is less than 10 kg/ha, and increased fertilizer use is seen by many as a fundamental need to improve production (IAASTD, 2009). However, fertilizers need to be part of an integrated fertility management plan that includes judicious use of organic fertility sources in combination with chemical fertilizer inputs (InterAcademy Council, 2004). Indeed, the IAASTD report suggested that research be reoriented from high-input blanket approaches to site-specific efficient application and integrated fertility management. Chapter 3 discussed the value of organic matter addition from such sources as green manures, cover crops, animal manure, and composts for both fertility and soil quality management. A number of examples show that a combination of inorganic and organic fertility inputs can have synergistic benefits, partly because of improved water retention (Evanylo et al., 2008; Sirrine et al., 2008; Toenniessen et al., 2008), which is critical in rain-fed agricultural systems.

  2. Integrated Water Management

    In the United States, agriculture’s use of water is becoming an increasingly critical issue. In some regions, water demand for alternative urban and industrial uses puts pressure on agriculture to reduce use, while in other areas, water resources are diminishing because of overuse (see Chapter 2). Individual farms might be highly efficient in water use, but

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

water overdraft in aggregate at a regional scale can become a driving factor for reduced use or abandonment of agricultural system types.

Issues of water use and scarcity loom large in much of Africa, especially sub-Saharan Africa. Water use and irrigation planning need to be done at a landscape and watershed or regional level, as illustrated for the United States, to identify areas of potential overdraft and to manage competition among different sectors for limited water supplies. However, the capacity for increasing the amount of irrigated cropland is small in sub-Saharan Africa, and most agricultural land will likely remain in rain-fed production systems, where small-scale water capture and storage systems are most appropriate.

In regions where shortages are occurring or are foreseen, developing a database of water use and implementing policies at appropriate local and regional scales are critical for managing the resource sustainably. As an example, a consortium of U.S. states and Canadian provinces bordering or using Great Lakes water and its ground water aquifers sets guidelines and policy under the U.S. Clean Water Act. (See Chapter 6.) All users are mandated to keep pumping-of-use records. Total use is coordinated with rainfall records and lake levels. Eventually, it will be necessary to allocate use, which requires historical records and projections for long-term use.

Because of the characteristics of agriculture in sub-Saharan Africa, it is generally agreed that smaller-scale irrigation and green water technologies, such as water conservation, rainwater harvesting, pumping from rivers on an individual and small group basis, and community-level water management, need to be explored as alternatives to large-scale irrigation projects (InterAcademy Council, 2004; NRC, 2008; IAASTD, 2009). In addition, the IAASTD report suggests some capacity for ground water pumping using medium-scale and irrigation techniques that require little infrastructural development and can reach many farmers (IAASTD, 2009). However, local and regional ground water overdrafts, as have occurred in other parts of the world, would have to be avoided.

Efficiency of water use also needs to be improved. Water-application efficiency can possibly be improved by using such techniques as land leveling and switching to more efficient irrigation methods such as drip systems. Drip systems currently might be too expensive for many small farmers, but some argue that it is worth exploring the potential for locally manufactured drip systems using recycled plastic bottles (NRC, 2008; IAASTD, 2009). Good soil management leading to increased organic matter will also help improve water use efficiency by allowing more water to percolate into the soil and increasing the water-holding capacity of soils. (See Chapter 3.)

  1. Technologies are needed to effectively address biotic constraints to production.

    Losses to pests, diseases, and weeds are substantial in developing countries, with estimates of 40 percent of potential yields lost to diseases and insects in Africa (NRC, 2008). The use of synthetic pesticides in those countries is likely to be limited because of cost and access constraints (InterAcademy Council, 2004); therefore, approaches such as integrated pest management (IPM), biological control, use of resistant crop varieties, development of disease-suppressive soils, and biopesticides could be as or more important than synthetic pesticides (NRC, 2008). Others also highlight diversification of the farming landscape as a way to encourage conservation biological control by providing habitat for natural enemy populations (World Bank, 2008; IAASTD, 2009).

    Some of the aforementioned approaches, as discussed in Chapter 3, are more advanced in their development than others. For example, IPM and the release of biological control organisms have had success in developing countries including Africa (see Chapter 3; NRC,

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

2008). Other techniques, such as manipulation of the rhizosphere to increase disease suppressiveness, need considerably more work to improve their success in African production systems. Efforts have been made in the United States to develop formulations of microorganisms associated with disease suppression, but those formulations have been used by few farmers because of a lack of reliable suppression. For that and other reasons, focusing on how to encourage soil suppressiveness through management—that is, by manipulating carbon inputs and designing crop rotation to increase and maintain populations of the beneficial microorganisms—might be more appropriate than developing microorganism formulations. Similarly the potential for use of induced resistance (see Chapter 3) is in its infancy in U.S. and African agriculture.

  1. Genetic improvement of both crops and animals will play an important role in the sustainable intensification of African agriculture.

    Active plant-breeding programs are essential for agricultural systems to respond to changing abiotic and biotic constraints that affect crop production. Host plant resistance is especially important for farmers with limited resources to purchase or use external inputs, such as pesticides. Similarly, tolerance to abiotic stresses such as drought, heat, and flood are increasingly important, especially for rain-fed agricultural systems. Unfortunately, government and donor support for public plant-breeding programs has not kept up with the needs of many developing countries. The plant-breeding programs and national program staff training efforts of the CGIAR Centers have been underfunded and understaffed for years. The lack of trained plant breeders has become an international concern and a number of recent initiatives have been established to train and support African plant-breeding programs.

    Facilitated by FAO, the Global Partnership Initiative for Plant Breeding Capacity Building (GIPB) is a multiparty initiative of institutions working with national agricultural programs to increase their plant-breeding capacity through the establishment of an Internet-based Knowledge Resource Center. The Knowledge Resource Center ’s shared information portal covers key areas such as training needs and opportunities, access to conventional and molecular-breeding technologies and genetic resources, general information on breeding programs, and other useful links.

    The African Centre for Crop Improvement (ACCI), established in 2004, is located at the Pietermaritzburg campus at the University of Kwa Zulu-Natal in South Africa. With initial support from the Rockefeller Foundation, and more recently from the Alliance for a Green Revolution in Africa (AGRA), the aim of ACCI is to train plant breeders from Eastern and Southern Africa using conventional and biotechnological breeding methods to improve African crops, with a focus on cereals, roots and tubers, and pulses. The students complete two years of course work at the university before returning to their home countries where they undertake three years of field study with the support of their university supervisors.

    Another recent program is a five-year, multipartner project on “Plant Molecular Breeding in the Developing World” funded in part by the Bill and Melinda Gates Foundation and the CGIAR Generation Challenge Program. The aim of the project is to use advanced genomic sciences and comparative biology to develop tools and technologies that will help plant breeders in the developing world produce better crop varieties for resource-poor famers, with an emphasis on drought tolerance and pest and disease resistance.

    Although most of the world’s diversity of livestock animals is in the developing world (FAO, 2007), conservation of animal genetic diversity and breeding improved breeds of key animal species in the region is very limited. FAO’s Global Plan of Action for Animal

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

Genetic Resources and the Interlaken Declaration on Animal Genetic Resources (FAO, 2007) noted with alarm the significant ongoing loss of livestock breeds throughout the world and recommended prompt action to conserve animal breeds at risk. The strategic priorities for action include: characterize, inventory, and monitor trends and associated risks to animal genetic resources; ensure sustainability in animal production systems with a focus on food security and rural development; preserve animal genetic diversity and integrity; and develop coherent and synergistic policies and institutions. The International Livestock Research Institute (ILRI) program for community-based management of indigenous farm animal genetic resources in Africa is one of a few efforts (International Livestock Research Institute, 2009a). It recognizes that community involvement is crucial for success and that farmers and pastoralists are innovative in finding ways to combine production and adaptation to their breeding stock.

  1. Sustainability and productivity could be improved by increased crop and livestock integration.

    Chapter 5 discusses the potential benefits of crop and livestock integration for the United States. For example, the ability to feed crops to livestock enables producers to capture and potentially recycle nutrients back to farm fields, which reduces the need for purchased fertilizers and enhances desirable soil attributes such as organic matter, water-holding capacity, and soil structure (Schiere et al., 2002; Entz et al., 2005; Hendrickson et al., 2007).

    Livestock serve a number of important roles in many African communities. They can serve as a source of meat or milk products, as draft animals for preparation of crop fields, as a store of wealth, and as an indicator of status and medium of exchange in important cultural rituals (such as marriage arrangements). While crop and livestock farmers have often been ethnically and operationally separate, groups of pastoralists and sedentary crop farmers have long been linked in functional ways (Powell et al., 2004). As population densities have increased, a growing number of integrated or mixed livestock and crop systems have developed across sub-Saharan Africa. In those systems, livestock can provide a vital source of manure to increase levels of soil quality and fertility that are critical for improving crop productivity throughout Africa. In turn, livestock are able to take advantage of underutilized resources, such as crop residues and less productive crop lands that can be converted to intensive pastures. Mixing livestock and crop enterprises can also add diversity to sources of food and income available to farmers and could increase the resilience of the farm system and reduce risk of food shortages.

    The IAASTD report specifically recommends the integration of crop, livestock, trees, and fish components where applicable as an important risk management strategy for sub-Saharan Africa in the face of unpredictable weather patterns and the prospects of global climate change (IAASTD, 2009). Efforts to improve the sustainability of crop production systems could benefit from integration of livestock enterprises within individual farms.

    Recent efforts to modernize and improve productivity of African commercial farms have also led to the development of large-scale specialized crop or livestock operations (more similar to dominant production systems found in the United States). Although specialization can create productivity or economic gains, it raises the potential for the loss of synergistic crop-livestock interactions and could generate more adverse social and environmental impacts, particularly in a political environment in which government capacity for regulation and oversight tends to be weak. Issues of nutrient imbalances, animal welfare, and animal health that are linked to the growth of concentrated animal feeding operations

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

in areas separated from crop production will likely need to be addressed, as discussed in the NRC report (2008). Given those structural changes, creative strategies to reintegrate livestock and crops at the regional scale may be required (Powell et al., 2004).

  1. Many processes and issues need to be addressed by landscape- and watershed-level planning and analysis.

    Sustainability and robustness of agroecosystems are defined by economic, social, and environmental characteristics at the farm, landscape, and regional levels. The scale and diversity of individual enterprises on the landscape is an important determinant of, for example, nutrient and water movement and vulnerability to extreme events. Also, higher-level catchment strategies are needed to optimize land and water use, address competition for water, and avoid developing overdrafts (InterAcademy Council, 2004). Similarly, spatial arrangements of habitats and their connectivity across the landscape are critical for effective management of native biodiversity (Kristhanson et al., 2009). The use of Geographic Information Systems (GIS) technology will be essential for the examination of landscape-and regional-level questions. The increasing numbers and scale of animal confinement operations that are evolving in response to market demand for quality livestock products, within Africa and in response to global market opportunities, present an important need for assessment of nutrient flows and local loading. Positioning of such facilities within watersheds to facilitate nutrient dispersal on the landscape for conservation and protection of water quality will present a new range of problems that require policy guidance, just as they do in highly developed economies.

    Management of grazing lands involves pastoralists being able to respond to variability in the spatial and temporal availability of resources. Strategies used include movement of livestock to follow quality and quantity of feed and water, flexible stocking rates, and herd diversification (IAASTD, 2009). Grazing systems are being challenged by changes in land tenure arrangements and stresses because of climate change. The latter will change the carrying capacities for livestock because of alternative predictions for changes in rainfall under different scenarios for climate change. The use of GIS will enable the development of spatially explicit models to provide insights into productivity patterns of the system and development of policies to ensure sustainability (IAASTD, 2009). Useful resources and linkages, particularly for African scientists, are available at the website of the International Livestock Research Institute (International Livestock Research Institute, 2009b).

SUMMARY

When considering the relevance of lessons learned in the United States to sub-Saharan Africa, it is important to recognize key differences between the two regions. Nonetheless, the concepts of sustainability and many of the broad approaches presented in this report are relevant and concur with conclusions from some recent international reports and they are summarized below.

  • Use of a systems approach with an interdisciplinary focus and understanding is essential, as is an awareness of the social, economic, and policy context within which farming systems operate.

  • Technologies to address soil, water, and biotic constraints are needed that integrate ecological processes and use locally available resources in combination with judicious use of external inputs when necessary.

  • Promising technological approaches include improving soil quality by organic

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

matter management and reduced tillage; integrated fertility management; water harvesting and use of drip irrigation; development of crop varieties that are resistant to environmental stress, diseases, and pests; development of improved animal breeds; greater integration of crops and animal production; and use of GIS to enable landscape and regional analysis and planning. Adoption of such technologies could be affected by multiple factors, including access to credit, that would have to be addressed to use available technologies.

  • Investment in agricultural R&D needs to increase, and the new commitment by African nations to respond to this need presents a critical opportunity to create a research and extension system that reflects an interdisciplinary systems approach to addressing agricultural problems.

  • New research programs would need to actively seek input and collaboration from farmers to ensure that appropriate research questions are being asked and technologies tested. Women play a critical role in African agriculture, and they need to be provided with educational and training opportunities and be involved in the development of research agendas.

  • Expansion of access to markets will be essential to increase productivity and enhance livelihoods in rural Africa. Investing in rural infrastructure could improve local, regional, and international market access.

  • The indigenous research and education system needs to be greatly strengthened, with institutions firmly grounded in interdisciplinary systems thinking and connected to local farmers and their production and livelihood needs.

REFERENCES

African Farmers Organization. 2009. African Farmers Organization Declaration on “The GCARD Regional Face-To-Face Consultation” held in Accra, Ghana. Available at http://gcardblog.wordpress.com/2009/10/13/ssa17/. Accessed on December 11, 2009.

African Green Revolution. 2009. AGR conferences. Available at http://www.africangreenrevolution.com/en/conferences/index.html. Accessed on June 4, 2009.

African Union Report. 2008. Progress report on implementing the comprehensive Africa agriculture development programme: agricultural growth, poverty reduction and food security in Africa. Presented at the 4th Conference of African Union Ministers of Agriculture, February 26–27, Addis Abba, Ethiopia.

Ashby, J.A. 1987. The effects of different types of farmer participation on the management of on-farm trials. Agricultural Administration and Extension 25(4):235–252.

Baudron, F., M. Corbeels, F. Monicat, and K.E. Giller. 2009. Cotton expansion and biodiversity loss in African savannahs, opportunities and challenges for conservation agriculture: a review paper based on two case studies. Biodiversity and Conservation 18(10):2625–2644.

Carter, M.R., S. Andrews, and L.E. Drinkwater. 2004. System approaches for improving soil quality. In Managing Soil Quality: Challenges in Modern Agriculture, P. Schjonning, B.T. Christensen, and S. Elmholt, eds. Oxford, UK: CAB International.

Cassman, K.G. 1999. Ecological intensification of cereal production systems: yield potential, soil quality, and precision agriculture. Proceedings of the National Academy of Sciences USA 96:5952–5959.

Delgado, C., M. Rosegrant, H. Steinfeld, S. Ehui, and C. Courbois. 1999. Livestock to 2020: The Next Food Revolution. Washington, D.C.: International Food and Policy Research Institute.

Denning, D., P. Kabambe, P. Sanchez, A. Malik, R. Flor, R. Harawa, P. Nkhoma, C. Zamba, C. Banda, C. Magombo, M. Keating, J. Wangila, and J. Sachs. 2009. Input subsidies to improve smallholder maize productivity in Malawi: toward an African Green Revolution. Plos Biology 7(1):e1000023.

Diao, X., P. Hazell, D. Resnick, and J. Thurlow. 2007. The Role of Agriculture in Development: Implications for Sub-Saharan Africa. Washington, D.C.: International Food and Policy Research Institute.

Dowd, B.M. 2008. Organic cotton in Africa: a new development paradigm? In Hanging by a Thread: Cotton, Globalization and Poverty in Africa, W. Moseley and L. Gray, eds. Athens: Ohio University Press.

Drinkwater, L.E. 2002. Cropping systems research: reconsidering agricultural experimental approaches. Hort-Technology 12(3):355–361.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

Entz, M.H., W.D. Bellotti, J.M. Powell, S.V. Angadi, W. Chen, K.H. Ominski, and B. Boelt. 2005. Evolution of integrated crop-livestock production systems. In Grassland: A Global Resource, D.A. McGilloway, ed. Wageningen, the Netherlands: Wageningen Academic Publishing.

European Technology Assessment Group. 2009. Agricultural Technologies for Developing Countries. Brussels: Author.

Evanylo, G., C. Sherony, J. Spargo, D. Starner, M. Brosius, and K. Haering. 2008. Soil and water environmental effects of fertilizer-, manure-, and compost-based fertility practices in an organic vegetable cropping system. Agriculture Ecosystems & Environment 127(1–2):50–58.

FAO (Food and Agriculture Organization). 2006. The State of Food Insecurity in the World 2006. Rome: Author.

———. 2007. The Global Plan of Action for Animal Genetic Resources and the Interlaken Declaration on Animal Genetic Resources. Available at http://www.fao.org/ag/againfo/programmes/en/genetics/documents/Interlaken/ITC-AnGR073_en.pdf. Accessed on February 23, 2010.

———. 2009a. How to feed the world 2050: the special challenge for Sub-Saharan Africa. Available at http://www.fao.org/fileadmin/templates/wsfs/docs/expert_paper/How_to_Feed_the_World_in_2050.pdf. Accessed on December 11, 2009.

———. 2009b. Conservation agriculture. Available at www.fao.org/ag/ca. Accessed on June 8, 2009.

Farrington, J., and A.M. Martin. 1998. Farmer participatory research: a review of concepts and recent fieldwork. Agricultural Administration and Extension 29:247–264.

Feder, G., R. Murgai, and J.B. Quizon. 2004a. The acquisition and diffusion of knowledge: the case of pest management training in Farmer Field Schools, Indonesia. Journal of Agricultural Economics 55(2):221–243.

———. 2004b. Sending farmers back to school: the impact of Farmer Field Schools in Indonesia. Review of Agricultural Economics 26(1):45–62.

Giller, K.E., E. Witter, M. Corteels, and P. Tittonell. 2009. Conservation agriculture and smallholder farming in Africa: the heretics’ view. Field Crops Research 114(1):23–34.

Gowing, J.W., and M. Palmer. 2008. Sustainable agricultural development in sub-Saharan Africa: the case for a paradigm shift in land husbandry. Soil Use and Management 24(1):92–99.

Hendrickson, J.R., J.D. Hanson, D.L. Tanaka, and G. Sassenrath. 2007. Principles of integrated agricultural systems: introduction to processes and definition. Renewable Agriculture and Food Systems 23(4):265–271.

IAASTD (International Assessment of Agricultural Knowledge, Science and Technology for Development). 2009. Summary for Decision Makers of the Global Report. Washington, D.C.: Author.

InterAcademy Council. 2004. Realizing the Promise and Potential of African Agriculture. Amsterdam: Author.

International Livestock Research Institute. 2009a. Improving the livelihoods of poor livestock keepers in Africa through community based management of indigenous farm animal genetic resources. Available at http://www.ilri.org/research/Print.asp?CCID=41&SID=85. Accessed on December 11, 2009.

———. 2009b. GIS services. Available at http://www.ilri.org/gis/. Accessed on October 9, 2009.

Kiers, E.T., R.R.B. Leakey, A.M. Izac, J.A. Heinemann, E. Rosenthal, D. Nathan, and J. Jiggins. 2008. Ecology—agriculture at a crossroads. Science 320:320–321.

Kristhanson, P., R.S. Reid, N. Dickson, W.C. Clark, D. Romney, R. Puskur, S. MacMillan, and D. Grace. 2009. Linking international agricultural research knowledge with action for sustainable development. Proceedings of the National Academy of Sciences USA 106(13):5047–5052.

Lado, C. 1998. The transfer of agricultural technology and the development of small-scale farming in rural Africa: case studies from Ghana, Sudan, Uganda, Zambia and South Africa. GeoJournal 45(3):165–176.

Marsden, T., and J. Murdoch. 2006. Between the Local and the Global: Confronting Complexity in the Contemporary Agrifood Sector. Vol. 12, Research in Rural Sociology and Development. San Diego, Calif.: Elsevier JAI.

Mendelsohn, R., A. Dinar, and A. Dalfelt. 2000. Climate change impacts on African agriculture. Available at http://www.ceepa.co.za/climate_change/pdf/(5-22-01)afrbckgrnd-impact.pdf. Accessed on March 9, 2010.

Meyer R. 2009. Agricultural technologies for developing countries. Available at http://www.itas.fzk.de/deu/ lit/2009/meye09a.pdf. Accessed on February 23, 2010.

Minten, B., L. Randrianarison, and J.F.M. Swinnen. 2009. Global retail chains and poor farmers: evidence from Madagascar. World Development 37(11):1728–1741.

Morgan, W.B., and J.A. Solarz. 1994. Agricultural crisis in sub-Saharan Africa—development constraints and policy problems. Geographical Journal 160:57–73.

National Fadama Development Project. 2010. National Fadama Development Project. Available at http://fadama.org/. Accessed on March 9, 2010.

Nelson, D.R., W.N. Adger, and K. Brown. 2007. Adaptation to environmental change: contributions of a resilience framework. Annual Review of Environment and Resources 32:395–419.

Neven, D., M.M. Odera, T. Reardon, and H.L. Wang. 2009. Kenyan supermarkets, emerging middle-class horticultural farmers, and employment impacts on the rural poor. World Development 37(11):1802–1811.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

NRC (National Research Council). 2008. Emerging Technologies to Benefit Farmers in Sub-Saharan Africa and South Asia. Washington, D.C.: National Academies Press.

Pontius, J., R. Dilts, and A. Bartlett. 2002. Ten years of IPM training in Asia—from Farmer Field School to community IPM. Bangkok: Food and Agriculture Organization of the United Nations.

Powell, J.M., R.A. Pearson, and P.H. Hiernaux. 2004. Crop-livestock interactions in the west African drylands. Agronomy Journal 96(2):469–483.

Pretty, J. 2008. Agricultural sustainability: concepts, principles and evidence. Philosophical Transactions of the Royal Society B: Biological Sciences 363:447–465.

Pretty, J.N., A.D. Noble, D. Bossio, J. Dixon, R.E. Hine, F.W.T. Penning de Vries, and J.I.L. Morison. 2006. Resource-conserving agriculture increases yields in developing countries. Environmental Science & Technology 40: 1114–1119.

Reardon, T., C.B. Barrett, J.A. Berdegue, and J.F.M. Swinnen. 2009. Agrifood industry transformation and small farmers in developing countries. World Development 37(11):1717–1727.

Runge, C.F., B. Senauer, P.G. Pardey, and M.W. Rosegrant. 2004. Ending Hunger in Africa: Prospects for the Small Farmer. Washington, D.C.: International Food and Policy Research Institute.

Sands, D.M. 1986. The Technology Application Gap: Overcoming Constraints to Small-Farm Development. Rome: Food and Agriculture Organization.

Schiere, J.B., M.N.M. Ibrahim, and H.v. Keulen. 2002. The role of livestock for sustainability in mixed farming: criteria and scenario studies under varying resource allocation. Agriculture, Ecosystems & Environment 90:139–153.

Sirrine, J.R., D.K. Letourneau, C. Shennan, D. Sirrine, R. Fouch, L. Jackson, and A. Mages. 2008. Impacts of ground-cover management systems on yield, leaf nutrients, weeds, and arthropods of tart cherry in Michigan, USA. Agriculture Ecosystems & Environment 125(1–4):239–245.

Snapp, S. 2002. Quantifying farmer evaluation of technologies: the mother and baby trial design. In Quantitative Analysis of Data from Participatory Methods of Plant Breeding, M.R. Bellon and J. Reeves, eds. Mexico: CIMMYT.

Snapp, S., G. Kanyama-Phiri, B. Kamanga, R. Gilbert, and K. Wellard. 2002a. Farmer and researcher partnerships in Malawi: developing soil fertility technologies for the near-term and far-term. Experimental Agriculture 38(4):411–431.

Snapp, S.S. 1999. Mother and baby trials: a novel trial design being tried out in Malawi. Target Newsletter of the Southern Africa Soil Fertility Network 17:8.

Snapp, S.S., and B. Pound, eds. 2008. Agricultural Systems: Agroecology & Rural Innovation for Development. Burlington, Mass.: Academic Press.

Snapp, S.S., D.D. Rohrbach, F. Simtowe, and H.A. Freeman. 2002b. Sustainable soil management options for Malawi: can smallholder farmers grow more legumes? Agriculture, Ecosystems & Environment 91:159–174.

Toenniessen, G., A. Adesina, and J. DeVries. 2008. Building an alliance for a Green Revolution in Africa. In Reducing the Impact of Poverty on Health and Human Development: Scientific Approaches, S. Kaler and O. Rennert, eds. Oxford: Blackwell Publishing.

Turner, B.L., R.E. Kasperson, P.A. Matson, J.J. McCarthy, R.W. Corell, L. Christensen, N. Eckley, J.X. Kasperson, A. Luers, M.L. Martello, C. Polsky, A. Pulsipher, and A. Schiller. 2003. A framework for vulnerability analysis in sustainability science. Proceedings of the National Academy of Sciences of the USA 100(14):8074–8079.

UNEP-UNCTAD (United Nations Environment Programme and United Nations Conference on Trade and Development Capacity Building Task Force on Trade, Environment and Development). 2008. Organic Agriculture and Food Security in Africa. Geneva; New York: United Nations.

United Nations. 2008. UN to review progress on the millennium development goals at high-level meeting in September 2010. Available at http://www.un.org/millenniumgoals/. Accessed on February 23, 2010.

van den Berg, H., and J. Jiggins. 2007. Investing in farmers: the impacts of farmer field schools in relation to integrated pest management. World Development 35(4):663–686.

Warner, K.D. 2006. Extending agroecology: grower participation in partnerships is key to social learning. Renewable Agriculture and Food Systems 21(2):84–94.

World Bank. 2008. World Development Report 2008: Agriculture for Development. Washington, D.C.: Author.

Suggested Citation: "8 Sustainable Agriculture in Sub-Saharan Africa: "Lessons Learned" from the United States." National Research Council. 2010. Toward Sustainable Agricultural Systems in the 21st Century. Washington, DC: The National Academies Press. doi: 10.17226/12832.

This page intentionally left blank.

Next Chapter: 9 Conclusions and Recommendations
Subscribe to Email from the National Academies
Keep up with all of the activities, publications, and events by subscribing to free updates by email.