Research Topics

EPAR Technical Report #303
Publication Date: 08/10/2015
Type: Data Analysis
Abstract

Common estimates of agricultural productivity rely upon crude measures of crop yield, typically defined as the weight harvested of a crop divided by the area harvested. But this common yield measure poorly reflects performance among farm systems combining multiple crops in one area (e.g., intercropping), and also ignores the possibility that farmers might lose crop area between planting and harvest (e.g., partial crop failure). Drawing on detailed plot-level data from Tanzania’s National Panel Survey, our research contrasts measures of smallholder productivity using production per hectare harvested and production per hectare planted.

An initial analysis (Research Brief - Rice Productivity Measurement) looking at rice production finds that yield by area planted differs significantly from yield by area harvested, particularly for smaller farms and female-headed households. OLS regression further reveals different demographic and management-related drivers of variability in yield gains – and thus different implications for policy and development interventions – depending on the yield measurement used. Findings suggest a need to better specify “yield” to more effectively guide agricultural development efforts.

 

EPAR Research Brief #312
Publication Date: 07/30/2015
Type: Literature Review
Abstract

This brief reviews the evidence of realized yield gains by smallholder farmers attributable to the use of high-quality seed and/or improved seed varieties. Our analysis suggests that in most cases, use of improved varieties and/or quality seed is associated with modest yield increases.  In the sample of 395 trials reviewed, positive yield changes accompanied the use of improved variety or quality seed, on average, in 10 out of 12 crops, with rice and cassava as the two exceptions.

EPAR Technical Report #245
Publication Date: 04/10/2015
Type: Data Analysis
Abstract

A farmer’s decision of how much land to dedicate to each crop reflects their farming options at the extensive and intensive margins. The extensive margin represents the total amount of agricultural land area that a farmer has available in a given year (referred to interchangeably as ‘farm size’ or ‘agricultural land’). A farmer increases land use on the extensive margin by planting on new agricultural land. The intensive margin represents area planted of crops as a proportion of total farm size. A farmer increases the intensive margin by increasing output within a fixed area. This analysis examines cropping patterns for households in Tanzania between 2008 and 2010 using data from the Tanzania National Panel Survey (TZNPS).  This brief describes changes in farm size, total area planted, and area planted of select annual crops to highlight the dynamic nature of farmer’s cropping choices for a sample population of 2,246 agricultural households that reported having any agricultural land in 2008 or 2010. Throughout the brief, we present summary statistics at the national level and compare them with household-level data to show how results vary depending on how the sub-population is defined and how average measures can mask household level changes. We analyze these questions in the context of smallholders (defined as households with total agricultural land area as less than two hectares) and farming systems.  

EPAR Technical Report #115
Publication Date: 12/14/2010
Type: Literature Review
Abstract

As part of the Crops & Climate Change series, this brief is presented in three parts: 1) An evaluation of the importance of Sorghum and Millet in SSA, based on production, net exports, and caloric need, 2) A novel analysis of historical and projected climate conditions in Sorghum and Millet growing regions, followed by a summary of the agronomic and physiological vulnerability of Sorghum and Millet crops, 3) A summary of current resources dedicated to sorghum and millet, based on research and development investments and National Adaptation Programmes of Action. Our analysis indicates that sorghum and millets may become increasingly important in those areas of SSA predicted to become hotter and subject to more variable precipitation as a result of climate change. Although sorghum and millet are currently grown on marginal agricultural lands and consumed for subsistence by poorer population segments, climate change could render these drought- and heat-tolerant crops the most viable future cereal production option in some areas where other cereals are currently grown. Fewer international development resources are currently devoted to sorghum and millet than are devoted to other cereal grains, and current resource allocation may not reflect the increased reliance on these grains necessitated by projected climactic changes.

EPAR Technical Report #114
Publication Date: 12/14/2010
Type: Literature Review
Abstract

As part of the Crops & Climate Change series, this brief is presented in three parts: 1) An evaluation of the importance of wheat in SSA, based on production, net exports, and caloric need, 2) A novel analysis of historical and projected climate conditions in wheat-growing regions, followed by a summary of the agronomic and physiological vulnerability of wheat crops, 3) A summary of current resources dedicated to wheat, based on research and development investments and National Adaptation Programmes of Action. Overall, this analysis indicates that the importance of wheat as an imported product remains high throughout SSA, though food crop production and dependence is concentrated in a relatively small area. Wheat-growing regions throughout SSA are likely to face yield decreases as a result of predicted rises in temperatures and possible changes in precipitation. Resources intended to aid adaptation to climate change flow primarily from public sector research and development efforts, though country-level adaptation strategies have not prioritized wheat.

EPAR Technical Report #102
Publication Date: 12/13/2010
Type: Literature Review
Abstract

Water is a critical input for significantly enhancing smallholder farmer productivity in Sub-Saharan Africa (SSA) where less than 5% of farm land is irrigated, and in India where 42% of farm land is irrigated.  For many years, donors have invested in human-powered treadle pump technologies as a point of entry for smallholder farmers unable to afford motorized pumps. In spite of some successes in treadle pump promotion, however, there is a widespread perception that as soon as smallholder farmers can afford to they quickly transition to motorized diesel- powered pumps. While diesel pumps substantially ease farmers’ workload, they pollute excessively (both in terms of local air quality and greenhouse gas emissions), pump excessive amounts of water, and put farmers at the mercy of cyclical spikes in fuel prices. This brief provides an overview of state-of-the-art alternative energy pumps, including technologies available and implementation lessons learned from China, India, Africa, South America and other regions. Through a literature review, written surveys and phone interviews with water pump producers and non-governmental organizations (NGOs) we evaluate the availability, affordability, and adoption rates of alternative energy technologies in developing countries. Our findings suggest that no single alternative energy water pumping system is a “silver bullet” for rural smallholder irrigation needs. Biofuels may prove a successful short- to intermediate-term solution for farmers who already have access to diesel pumps, but other problems associated with diesel engines, including high maintenance costs and excessive water use remain even when biofuels are used. Solar systems eliminate pollution almost entirely, reduce water consumption, and eliminate the need to purchase fuels. However solar systems are typically prohibitively expensive for smallholder farmers. Wind powered pumping solutions have not proven successful to date, with high costs and irregular wind patterns (either too little or too much wind) proving substantial barriers to widespread adoption.

EPAR Technical Report #62
Publication Date: 10/23/2010
Type: Literature Review
Abstract

Researchers expect that agriculture in Sub-Saharan Africa (SSA) will experience major impacts from climate change, leaving the already food-insecure region subject to the largest contractions of agricultural incomes and food availability. As part of the Crops & Climate Change series, this brief presents an evaluation of the importance of maize in SSA, a novel analysis of historical and projected climate conditions in maize-growing regions, and a summary of current resources dedicated to maize adaptation. Overall, this analysis indicates that the importance of maize as a food crop remains high throughout SSA. Significant portions of maize-growing SSA will face climate conditions outside the range of country- and continent-level historical precedent. Rising temperatures and changes in precipitation are predicted, and reductions in maize yield and production will likely follow. Resources intended to aid adaptation to climate change flow primarily from public sector research and development efforts. Country-level adaptation strategies are often hampered by lack of funding and insufficient institutional capacity. Strategies for adaptation include improved agricultural practices and technology as well as infrastructure and program investments to absorb the impacts of climate change.

EPAR Technical Report #71
Publication Date: 10/22/2010
Type: Literature Review
Abstract

Agriculture in Sub-Saharan Africa is expected to experience major impacts from climate change, leaving the already food-insecure region subject to the largest contractions of agricultural incomes and food availability. As part of the Crops & Climate Change series, this brief presents an evaluation of the importance of rice in SSA, a novel analysis of historical and projected climate conditions in rice-growing regions in relation to rice's agronomic requirements, and a summary of current resources dedicated to rice. This three-pillared approach serves to identify gaps in resources dedicated to rice productivity in SSA in light of the crop’s resilience to projected changes in climate and increasing importance in the region’s food security. Overall, this analysis indicates that the importance of rice in SSA is increasing even as climate change is projected to have significant effects on the temperature in rice-growing regions. The current resources dedicated to rice research and dissemination of improved methods are insufficient to meet Africa’s rice production needs, and may not reflect the importance of the crop for the region’s food security under the future projected climate.

EPAR Technical Report #98
Publication Date: 10/12/2010
Type: Literature Review
Abstract

Cereals and pulses are important food and cash crops for farmers and rural households in Ethiopia. Despite the economic and food security importance of these crops, data and opinion suggest a yield gap: actual smallholder farm yields do not achieve estimated potential yields for wheat, sorghum, maize, lentils and peas. Furthermore, cereal prices in Ethiopia fall between import and export parity prices, limiting their international trading prospects. Although there are significant wheat imports, these reflect the influx of food aid, rather than competitive trade on the international market. The purpose of this brief is to estimate yield gaps in important Ethiopian crops in order to identify potential areas for productivity gains. We find that wheat, sorghum and maize all exhibit the potential for yield gains to increase domestic food availability. Additionally, all three crops experienced significant spikes in yield in the 2006 season. Further investigation into the climate conditions and policy in place that year may generate potential strategies to increase future yields. Analysis of Ethiopian lentil and pea yields suggest that productivity gains may be possible to increase food availability. Limited access to improved technologies appears to be the main constraint to pulse productivity in Ethiopia. Opportunities to increase lentil and pea yields appear to exist through increasing cultivation of improved varieties.

EPAR Research Brief #67
Publication Date: 03/08/2010
Type: Literature Review
Abstract

Contract farming (CF) is an arrangement between farmers and a processing or marketing firm for the production and supply of agricultural products, often at predetermined prices. This literature review builds on EPAR's review of smallholder contract farming in Sub-Saharan Africa (SSA) and South Asia (EPAR Technical Report #60)  by specifically examining the evidence on impacts and potential benefits of contract farming for women in SSA. Key takeaways suggest women’s direct participation in contract farming is limited, with limited access to land and control over the allocation of labor and cash resources key constraints hindering women’s ability to benefit from CF. Further, we find that the impact of contract farming on women is often mediated by their relative bargaining power within the household.