Research Topics

EPAR Technical Report #34
Publication Date: 05/03/2009
Type: Literature Review
Abstract

Lack of nitrogen (N) is often cited as the most limiting factor in agriculture. Although N composes nearly 80% of the atmosphere, plants are unable to use this form of the element (N2) because of the strong triple bonds between the two atoms. Nitrogen deficiency is especially problematic in the soils of Sub-Saharan Africa (SSA). Low levels of N and other soil fertility problems have severe poverty, malnutrition and environmental degradation consequences for SSA. The process by which atmospheric N2 is converted into N compounds that can be used by living things is called nitrogen fixation. Biological nitrogen fixation (BNF or biofixation) offers an alternative or additional means to traditional nitrogen fixation to increase plant-available nitrogen. Through a symbiotic relationship, an N-fixing bacterium infects a plant (usually a legume) and forms nodules on the roots of the plant in which N fixation occurs. This literature review examines the expansion and benefits of BNF, the constraints to BNF adoption, BNF regulations, and success stories of developing and distributing BNF technologies worldwide. BNF technology can be an efficient and effective tool for decreasing environmental degradation and increasing soil fertility, yields, income, and food security in SSA, although many constraints to farmer adoption exist. 

EPAR Technical Report #18
Publication Date: 04/15/2009
Type: Literature Review
Abstract

This report present a thorough review of relevant literature regarding labor constraints currently being faced in Sub-Saharan Africa (SSA).  The review focuses on the impacts of labor supply issues, particularly as they relate to the use of new technology and management techniques, off farm labor migration, and the impacts of HIV/AIDS. The review is provides a basic breakdown of the different kinds of agricultural labor in SSA, before presenting the evidence on the causes and impact of agricultural labor constraints. Though labor constraints can be relevant on both the demand and supply side, especially for certain groups such as women and youth, our review follows the literature by focusing on the supply side issues. The literature reviewed was written between 1990 and 2008, and includes a combination of reports from government organizations and highly cited journal articles.

EPAR Research Brief #99
Publication Date: 01/31/2009
Type: Literature Review
Abstract

Aflatoxin is a naturally occurring carcinogen produced by the fungus Aspergillus, particularly Aspergillus Flavus and Aspergillus Parasiticus. Aflatoxin contamination places an economic and health burden on farmers throughout the developing world, but reliable prevalence data are difficult to obtain. This report analyzes data from 25 primary research articles published within the last 15 years in order to provide a summary of aflatoxin contamination in the developing world. This report is divided into three parts, roughly aligning with phases of the agricultural value chain. Data for prevalence at the production and processing stage are presented first, followed by data for prevalence during storage, and finally by a summary of data for aflatoxin levels at consumption and point-of sale. We find maize and groundnuts to be the crops most affected by aflatoxin, while Southeast Asia and Sub-Saharan Africa are the geographic areas most likely to be affected. Agroecological conditions including warm humid climates, irrigated hot deserts, and droughts contribute to aflatoxin contamination, and we find that contamination can occur throughout the value chain. 

EPAR Technical Report #5
Publication Date: 12/15/2008
Type: Literature Review
Abstract

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. 

EPAR Research Brief #2
Publication Date: 10/30/2008
Type: Literature Review
Abstract

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.

EPAR Research Brief #4
Publication Date: 10/22/2008
Type: Literature Review
Abstract

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.