Populations

Dataset

EPAR Technical Report #207
Publication Date: 12/17/2012
Type: Literature Review
Abstract

This report provides a general overview of the markets for yams in Nigeria. The first section describes trends in yam production and consumption and international trade since 1990. The second section summarizes the varieties grown in Nigeria and their uses, followed by a discussion of the importance of yams as a source of nutrition and household income. The final section provides details about the production and marketing systems for yams in Nigeria, including environmental and gender considerations. Nigeria is the world’s largest yam producer in terms of quantity. Yam production and consumption have increased over the past twenty years, though more recently, production has been somewhat in decline and yields have been stagnant. The Nigerian government has played a more active role in improving agricultural production and export of root and tuber crops including yams in recent years, but so far with limited success. Yam producers and traders report diverse constraints to their full participation in the market, including high cost of inputs, planting materials and labor, lack of credit, limited access to proper, secure storage facilities, and high transportation costs.

EPAR Technical Report #211
Publication Date: 12/14/2012
Type: Literature Review
Abstract

This report provides a general overview of the sweet potato value chain in Tanzania. The first section describes trends in sweet potato production and consumption since 1990. The second section describes the uses and importance of sweet potatoes in Tanzania. The final section outlines current practices and constraints in production, post-production, and marketing. Tanzania ranks fifth in the world in quantity of sweet potatoes produced. Production and consumption of sweet potatoes have been relatively constant over the past 10 years, although both production and consumption in this period have been high in comparison to earlier decades. We find that sweet potato yields increased in the early 2000s, but have stagnated since, and are far short of potential yields. Sweet potato consumption is almost entirely domestic and plays an important role in nutrition and food security for smallholder farmers. Sweet potato production faces a variety of constraints, including pests and disease, short shelf life, lack of planting materials, damage during handling, and lack of market access.

EPAR Technical Report #206
Publication Date: 12/12/2012
Type: Literature Review
Abstract

This report provides a general overview of the market for yams in Ghana. We begin by describing historical trends in yam production and consumption since 1996, recent international trade, and prices. The second section summarizes the varieties grown in Ghana and their uses. The next several sections review available information about the production and marketing systems, followed by a discussion of the importance of yams as a source of nutrition and household income. The limited information available on sweet potato production in Ghana is presented in the appendix. We find that yam production in Ghana has increased steadily over the last 15 years, and that while yam yields have increased from 12.8 MT/Ha in 1996 to 15.6 MT/Ha in 2011, an estimated yield gap of 33.4 MT/Ha persists. Yam export levels have varied over the past 15 years, but show a generally positive trend. Most yam farmers are male smallholders with low levels of education, while most retailers, wholesalers and cross-border traders are women.

EPAR Technical Report #223
Publication Date: 12/10/2012
Type: Literature Review
Abstract

Cassava is a tuber crop originating in South America and grown in tropical and subtropical areas throughout the world. Cassava use varies significantly by region. In Africa, cassava is primarily grown for food. In Asia, production is typically for industrial purposes, including ethanol, while in Latin America and the Caribbean it is commonly used in animal feed. Both roots and leaves are consumed, though most information on production focuses on roots. There are bitter and sweet varieties; bitter cassava has a high cyanide content and must be processed prior to consumption, while sweet varieties can be eaten directly. This report presents information about current production, constraints, and future potential of cassava. We discuss cassava’s importance in Africa, current worldwide production, projections for supply and demand, production constraints, and current policies affecting cassava production and trade. We include global information but focus on Africa, particularly Nigeria, Ghana, Uganda, and Tanzania.

EPAR Technical Report #199
Publication Date: 07/27/2012
Type: Literature Review
Abstract

Over the past 20 years, global wheat production and consumption have increased significantly. Production has increased 28%, or about 1.3% annually, and consumption has increased about 24%, or 1.1% annually. A small number of countries consistently account for over 90% of the export market, but the import market is more diversified and involves many more countries. Wheat is primarily used for food, seed, and industry; only 20% of wheat production is used for animal feed. This brief provides a global overview of the wheat value chain, but with specific attention to three focus countries: Ethiopia, India (specifically the Bihar region), and Bangladesh. While these three countries currently have a limited impact in the global wheat market, projections of wheat production and demand suggest that over the next 20 years demand in Bangladesh and Ethiopia will increasingly exceed supply, while India will become a net importer by 2030.

EPAR Technical Report #204
Publication Date: 07/27/2012
Type: Literature Review
Abstract

This report provides a general overview of the wheat market in Ethiopia. The first section describes trends in wheat production and consumption over the past twenty years and summarizes recent trade policy related to wheat. The second section presents the findings of a literature review of the wheat value chain in Ethiopia, beginning with seed research and ending with sales. The third section outlines the nutritional content of wheat as well as potential substitutes. Finally, wheat consumption in Ethiopia is discussed in more depth, including the role of wheat in Ethiopian diets, substitute grain markets, and projected consumption in 2030. We find that over the past twenty years, wheat production and consumption have both increased in Ethiopia despite the existence of strong markets for potential substitute grains. The Ethiopian government has played an active role in wheat markets, such as making large investments in extension programs and adopting protectionist policies to ensure government control of all commercial grain imports. Despite these efforts, Ethiopia is expected to face a growing supply deficit in the absence of increased domestic productivity and/or changes to government policy. 

EPAR Research Brief #158
Publication Date: 08/03/2011
Type: Literature Review
Abstract

This literature review examines the environmental impacts of water buffalo in pastoral and mixed farming systems in Sub-Saharan Africa, South Asia, and South America). The environmental impacts of water buffalo are less widely studied than those of the other livestock species included in this series; typically, the environmental impacts of water buffalo are incorporated into discussions of cattle without more detailed impacts being broken down by bovine type. In Asia and India, where the majority of buffalo are raised, buffalo are typically kept in small herds of only a few animals, which may minimize the local impacts of their grazing on vegetation, soil erosion and water pollution. Some aspects of buffalo feeding and life cycle patterns, as observed in the Amazon, may cause their greenhouse gas emissions to differ from those of cattle: buffalo can fatten on a wider range of grasses, reach market size in a shorter time, transition better from dry to wet seasons, and are more resistant to bovine diseases. While buffalo grazing and trampling can lead to land degradation, buffalo can contribute to nutrient and resource cycling in farming systems because their manure is considered good fertilizer and they can remove and utilize biomass grown on agricultural plots. Mitigation strategies vary by category of environmental impact, but largely suggest improved productivity to reduce land conversion, modified management systems (e.g., biodiversity, water use and consumption, farm and pastures, and waste), and the reduction of livestock numbers altogether.

EPAR Research Brief #155
Publication Date: 07/31/2011
Type: Literature Review
Abstract

This literature review examines the environmental impacts of cattle in pastoral and mixed farming systems in Sub-Saharan Africa and South Asia. Cattle are frequently cited as having the most severe overall environmental impacts among livestock species due to: methane and nitrous oxide released from digestion and manure; land use and conversion; desertification; inefficient ratio of weight of feed and water consumed to weight of meat and dairy produced; conflicts between livestock herders and wildlife; the large volume of wastewater produced in meat and hide processing; and overgrazing of riparian areas. However, cattle have also been found to provide several environmental benefits such as keeping wildlife corridors open, preventing the spread of noxious weeds, and promoting the growth of local vegetative species. Mitigation strategies vary by category of environmental impact, but largely suggest improved productivity to reduce land conversion, modified management systems (e.g., biodiversity, water use and consumption, farm and pastures, grain and other feed, and waste), and the reduction of livestock numbers altogether. 

EPAR Research Brief #156
Publication Date: 07/31/2011
Type: Literature Review
Abstract

This literature review examines the environmental impacts of goats in pastoral and mixed farming systems in Sub-Saharan Africa and South Asia. We find that the most notable environmental implications of goats stem from their ability to graze on a wide variety of biomass sources in frequently marginal environments; while this intensive grazing stimulates biodiversity loss and may be more severe than grazing by other livestock species, goats are not a major driver of forest clearing due to their low economic value. Environmental benefits of goat production include keeping wildlife corridors open, preventing the spread of noxious weeds, and promoting the growth of local vegetative species through moderate grazing. Goats are also more water-efficient than large ruminants such as cattle. Mitigation strategies vary by category of environmental impact, but largely suggest improved productivity to reduce land conversion, modified management systems (e.g., biodiversity, water use and consumption, grazing intensity and frequency, and waste), and the reduction of livestock numbers altogether.

EPAR Research Brief #157
Publication Date: 07/31/2011
Type: Literature Review
Abstract

This literature review examines the environmental impacts of chickens in pastoral and mixed farming systems in Sub-Saharan Africa and South Asia. Compared to ruminant species (cattle, water buffalo, and goats), chickens produce lower carbon dioxide, methane, and nitrous oxide emissions, are a less significant driver of human expansion into natural habitat or of overgrazing, have lower impacts on the water cycle, and cause less destruction of natural habitats. Poultry’s major impacts on land degradation result from the production of their grain-intensive feed. Chicken production also poses a threat to avian biodiversity, as chickens are susceptible to viruses and act as vectors of disease transmission to avian wildlife. Chicken manure is widely viewed as a valuable fertilizer in developing countries, although transportation costs limit manure sales in local markets and the high nitrogen-phosphorous ratio can impact certain soils and water. Mitigation strategies vary by category of environmental impact, but largely suggest modified management systems (e.g., biodiversity, health, livestock feed efficiency, and waste).