Types of Research
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.
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.
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).
This report combines analyses from four previous EPAR briefs on the effects of climate change on maize, rice, wheat, sorghum, and millet production in Sub-Saharan Africa (SSA). In addition, this brief presents new analysis of the projected impact of climate changes in SSA. We include comparisons of the importance of each crop, of their vulnerability to climate change, and of the research and policy resources dedicated to each. Especially with respect to climatic susceptibility, these rankings provide a comparative summary based upon the analysis conducted in the four previous EPAR briefs, statistical analyses of historical yield and climate data, and future climate model predictions. According to the indicators analyzed, our research suggests that maize leads the cereal crops in terms of importance within SSA and in terms of research and policy attention. Our analysis of climate conditions and the crop’s physical requirements suggests that many maize-growing areas are likely to move outside the range of ideal temperature and precipitation conditions for maize production. Rice is the third most important crop in terms of consumption dependency, fourth in terms of production, but second only to maize in terms of research funding and FTEs. Sorghum and millet rank second and third in production importance and second and fifth in consumption importance, but rank below maize and rice in terms of FTE researchers. Their role is complicated by the fact that they are often considered inferior goods; SSA consumers often substitute away from sorghum and millet consumption if they are able to do so. Wheat is the least-produced crop of the five, and the second to last in terms of consumption importance. However, it still ranks above millet in terms of FTE researchers.
As our understanding of the impacts of hidden hunger on human nutrition grows, understanding the link between fertilizer use and human nutrition becomes increasingly important. This report presents an analysis of both grey and peer-reviewed literature on the effects of fertilizer use on nutritional quality of food, particularly the staples of maize, rice, wheat, cassava and legumes. We find that some nutrient deficiencies, such as zinc, can be effectively addressed through fertilizer use while others, such as iron deficiency, are more difficult to address. Promising breakthroughs with fortified and complete fertilizers present the opportunity to correct multiple deficiencies. Current fertilizer products exist that, when applied with the proper agronomic methods, can have a significant effect on nutrition in the developing world. However, it is important to recognize that there are many factors in the developing world that have the potential to inhibit the benefits of fertilizer for human nutrition. Two significant factors are poor farmers’ difficulty in procuring the correct product and the relative sophistication required to apply fertilizers at the correct amounts and time to achieve desired results. In addition, researchers have not focused on fertilizer and nutrition studies until recently, particularly micronutrient fertilizer studies, and few studies specifically study the impacts of fertilizer on human nutrition. More research needs to be done to understand the most effective combinations and techniques, and to understand whether these methods truly increase the amount of nutrients bioavailable to humans.
This brief reviews the literature on the links between agriculture and human nutrition in rural South Asia, exploring why South Asia has experienced enormous growth in agricultural productivity without subsequent reductions in hunger. An annotated review of relevant articles is included in addition to the analysis. The articles are presented by sub-topic, including sustained economic growth versus lack of progress in nutrition rates and hunger in South Asia, primary determinants of improved nutrition at the household level, agricultural productivity/reform and interventions in nutritional status.
We conducted a literature review of strategic grain reserves (SGRs) are used to mitigate food crises. Our brief includes a short overview of the literature and a bibliography of top-cited articles relevant to specific sub-topics related to SGRs.