Types of Research

Dataset

EPAR Research Brief #228
Agriculture & the Environment: Cassava Systems
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.

Full Brief
EPAR Technical Report #254
Agriculture & the Environment: Overview
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.

Full Report, Presentation Slides, Published Paper
EPAR Research Brief #75
Political Economy of Fertilizer Policy in Tanzania
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.

Literature Review
EPAR Research Brief #79
Political Economy of Fertilizer Policy in Kenya
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.

Literature Review
EPAR Research Brief #99
Aflatoxin Prevalence in the Developing Worlds
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. 

Literature Review, Results Coding