Research Topics

EPAR Research Brief #228
Publication Date: 04/18/2014
Type: Literature Review
Abstract

Cassava (Manihot esculenta Crantz) is a widely-grown staple food in the tropical and subtropical regions of Africa, Asia, and Latin America. In this brief we examine the environmental constraints to, and impacts of, smallholder cassava production systems in Sub-Saharan Africa (SSA) and South Asia (SA), noting where the analysis applies to only one of these regions. We highlight crop-environment interactions at three stages of the cassava value chain: pre-production (e.g., land clearing), production (e.g., soil, water, and input use), and post-production (e.g., crop storage). At each stage we emphasize environmental constraints on production (poor soil quality, water scarcity, crop pests, etc.) and also environmental impacts of crop production (e.g., soil erosion, water depletion and pesticide contamination). We then highlight good practices for overcoming environmental constraints and minimizing environmental impacts in smallholder cassava production systems. Evidence on environmental issues in smallholder cassava production is relatively thin, and unevenly distributed across regions. The literature on cassava in South Asian smallholder systems is limited, reflecting a crop of secondary importance (though it is widely found elsewhere in Asia such as South East Asia), in comparison to cassava in much of SSA. The majority of the research summarized in this brief is from SSA. The last row of Table 1 summarizes good practices currently identified in the literature. However, the appropriate strategy in a given situation will vary widely based on contextual factors, such as local environmental conditions, market access, cultural preferences, production practices and the policy environment.

EPAR Technical Report #254
Publication Date: 03/20/2014
Type: Literature Review
Abstract

This overview introduces a series of EPAR briefs in the Agriculture-Environment Series that examine crop-environment interactions for a range of crops in smallholder food production systems in Sub-Saharan Africa (SSA) and South Asia (SA). The briefs cover the following important food crops in those regions; rice (#208), maize (#218), sorghum/millets (#213), sweet potato/yam (#225), and cassava (#228).

Drawing on the academic literature and the field expertise of crop scientists, these briefs highlight crop-environment interactions at three stages of the crop value chain: pre-production (e.g., land clearing and tilling), production (such as water, nutrient and other input use), and post-production (e.g., waste disposal and crop storage). At each stage we emphasize environmental constraints on crop yields (including poor soils, water scarcity, crop pests) and impacts of crop production on the environment (such as soil erosion, water depletion and pest resistance). We then highlight best practices from the literature and from expert experience for minimizing negative environmental impacts in smallholder crop production systems.

This overview (along with the accompanying detailed crop briefs) seeks to provide a framework for stimulating across-crop discussions and informed debates on the full range of crop-environment interactions in agricultural development initiatives.

A paper based on this research series was published in Food Security in August 2015.

EPAR Research Brief #52
Publication Date: 11/09/2009
Type: Literature Review
Abstract

Ecological farming and conventional farming are two approaches to producing food. The term “ecological farming” describes a range of agricultural systems that seek to provide food and environmental and social benefits by using natural processes and local resources rather than off-farm, purchased inputs (commonly referred to as “external inputs”). Recent debate about the merits of ecological farming over conventional methods has centered on each system’s ability to increase production in the context of numerous and varied biophysical and social constraints. A review of the literature suggests that ecological farming can offer some benefits to smallholder farmers, but that specific approaches must be tailored to local climate and soil conditions and availability of labor, training, and organic inputs.

EPAR Research Brief #75
Publication Date: 11/02/2009
Type: Literature Review
Abstract

In Tanzania, agriculture represents approximately 50 percent of GDP, 80 percent of rural employment, and over 50 percent of the foreign exchange earnings. Yet poor soil fertility and resulting low productivity contribute to low economic growth and widespread poverty. Chemical fertilizer has the potential to contribute to crop yield increases. Yet high prices and weaknesses in the fertilizer market keep fertilizer use low. This literature review examines the history of government interventions that have intended to increase access to fertilizers, and reviews current policies, market structure, and challenges that contribute to the present conditions. We find that despite numerous strategies over the last fifty years, from heavy government involvement to liberalization, major weaknesses in Tanzania’s fertilizer market prevent efficient use of fertilizer. High transportation costs, low knowledge level of farmers and agrodealers, unavailability of improved seed, and limited access to credit all contribute to the market’s problems. The government’s current framework, the Tanzania Agriculture Input Partnership (TAIP), acknowledges this interconnectedness by targeting multiple components of the market. This model could help Tanzania tailor solutions relevant to specific road, soil, and market conditions of different areas of the country, contributing to enhanced food security and economic growth.

EPAR Research Brief #44
Publication Date: 08/17/2009
Type: Literature Review
Abstract

Bt maize technology involves developing hybrid maize crops that incorporate genes from the soil-dwelling bacteria Bacillus thuringiensis (Bt). The primary benefit of Bt maize technology is the heightened crop protection from stem borers, which are maize pests that can inflict serious crop losses. Bt maize has been cultivated in Mexico, South Africa and several countries in the European Union, with limited cultivation in Sub-Saharan Africa (SSA). This report provides a summary of literature on the potential benefits and challenges associated with Bt maize production in SSA. Research studies of Bt maize in the Philippines and South Africa are also briefly reviewed. There is little peer-reviewed literature available, with evidence challenging the assumed benefits of Bt maize for smallholder farmers in SSA. As a result, we also review research briefs and conference proceedings available from reputable international organizations. Although some of the available literature references the ethical concerns over Bt maize production, we focus on searching for science-based discussions related to any potential biodiversity, biosafety, or socio-economic impacts of Bt maize technology for smallholder farmers in SSA.

EPAR Technical Report #28
Publication Date: 08/10/2009
Type: Literature Review
Abstract

Smallholder farmers in Africa are largely located in poor rural areas, are often geographically dispersed, and have limited access to road and communication infrastructure, thus raising the cost of market participation. This is especially true for farmers growing relatively low value staple crops. This literature review summarizes research on the challenges and innovations in linking smallholder producers of staple grains to markets in Sub-Saharan Africa, with a focus on post-harvest issues including storage, aggregation, and transportation. For each post-harvest stage, we describe challenges faced by farmers and current efforts to address these challenges. In our review, we find a large amount of literature on the constraints to smallholder production and marketing but relatively few examples of innovative or novel technologies designed to improve storage and transportation for rural smallholder producers in Africa. Existing technologies have often been available for some time but have not seen widespread adoption, apparently due to high costs or inadequate funding for on-farm testing and extension. We conclude that the literature is somewhat divided as to whether interventions linking smallholder farmers to markets should be entirely market-driven and focus on linkages that can be profitable without subsidization, or whether NGO- and donor-driven interventions should play a role.

EPAR Research Brief #79
Publication Date: 07/29/2009
Type: Literature Review
Abstract

The Government of Kenya (GoK) has historically encouraged its farmers to use fertilizer by financing infrastructure and supporting fertilizer markets.  From 1974 to 1984, the GoK provided a fertilizer importation monopoly to one firm, the Kenya Farmers Association.  However, the GoK saw that this monopoly impeded fertilizer market development by prohibiting competing firms from entering the market and, in the latter half of the 1980s, encouraged other firms to enter the highly regulated fertilizer market. This report examines the state of fertilizer use in Kenya by reviewing and summarizing literature on recent fertilizer price increases, Kenya’s fertilizer usage trends and approaches, market forces, and the impact of government and non-government programs. We find that most studies of Kenya’s fertilizer market find it to be well functioning and generally competitive, and conclude that market reform has stimulated fertilizer use mainly by improving farmers’ access to the input through the expansion of private retail networks. Overall fertilizer consumption in Kenya has increased steadily since 1980, and fertilizer use among smallholders is among the highest in Sub-Saharan Africa. Yet fertilizer consumption is still limited, especially on cereal crops, and in areas where agroecological conditions create greater risks and lower returns to fertilizer use.

EPAR Research Brief #32
Publication Date: 06/30/2009
Type: Literature Review
Abstract

Though not indigenous to Sub-Saharan Africa (SSA), cassava plays, to varying degrees, five major roles in African development: famine-reserve crop, rural food staple, cash crop for urban consumption, livestock feed, and industrial raw material. Cassava production in SSA was historically a significant staple crop for smallholder farmers and continues to be the second most important food crop in Africa (after maize) in terms of calories consumed. Subsistence crops such as cassava are often considered women’s crops with the standard explanation that women are responsible for feeding the family and thus prefer to grow crops for the household. This brief reviews the role that women play in cassava production, and considers ways to better address gender issues from planting through post-harvest production. We find that the potential gains to cassava production made possible through improved technology will not be fully realized without the participation of women farmers and without women farmers having access to credit, markets, and extension services. Additionally, evidence from SSA suggests that labor for harvesting and processing, rather than labor for weeding, has become the key labor constraint for cassava, and addressing this concern may be more important than further yield increases for raising production levels.

EPAR Technical Report #35
Publication Date: 05/13/2009
Type: Literature Review
Abstract

This report provides a general overview of trends in public and private agricultural research and development (R&D) funding and expenditures in Sub-Saharan Africa (SSA). The request is divided into two sections, covering public funding and private funding. Within each section, relevant data is presented on historical funding patterns, the types of research conducted, and which countries within SSA are financing R&D at the highest level. We find that the majority of growth in African public agricultural research funding took place in the 1960s, when real public spending on agricultural research increased 6% a year. From 1971 to 2000 annual growth averaged 1.4% a year. Public financing of agricultural R&D experienced a moderate shift in the 1990s from bilateral and multilateral donor funding to domestic government financing. The shift varied by country, but donor funding dropped for all SSA countries an average of 10%. Private research and development funding is heavily concentrated in developed countries with the United States and Japan the two biggest spenders. Within SSA, private R&D expenditures comprise 2% of all R&D spending. The main private actors in SSA are companies based in South Africa and Nigeria. The private sector is focused on research areas that involve marketable inputs, such as chemicals, seeds, and machines/

EPAR Research Brief #27
Publication Date: 05/09/2009
Type: Literature Review
Abstract

As a source of employment for over 20 million Sub-Saharan African (SSA) farmers and the fastest-growing food source in Africa, rice plays a vital role in African economies and daily life. Women play a substantial role in SSA rice production and rely heavily on the income it generates. Not recognizing this role has often resulted in development and research projects failing to address women’s well-being and also failing to achieve project and development goals. Female farmers in SSA have been less likely than male farmers to adopt productivity-enhancing rice technologies such as improved seeds, fertilizer, pesticides, or small machinery, even when those technologies are designed specifically to help women. A more complete understanding of the dynamics and diversity of gender roles in rice farming is necessary to improve the likelihood of successful interventions. This brief provides an overview of the role of women in rice production, and provides a framework for analyzing technology’s impact on women throughout the cropping cycle. We find that labor constraints, low education levels, cultural inappropriateness, and asymmetric access to resources all contribute to low adoption of rice technology by women. In order to fully realize the poverty reduction benefits of increased rice production in SSA, evidence suggests that research and extension programs must consider how interventions will affect women along every stage of the production chain. The effect on women and their households will vary depending on region, culture, ethnicity, socio-economic status, and role in cultivating rice.