1,678 research outputs found

    Maize breeding in East and Southern Africa, 1900–2000

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    "During the first half of the 20th century, African farmers transformed maize from a minor imported foodcrop into the continent's principal staple food. In the second half of the century, newly independent governments launched support programs that greatly expanded smallholder production, leading to substantial production surges of 10 to 20 years in duration. Today, after widespread adoption by both commercial farmers and smallholders, farmers now plant 58 percent of all maize area in East and Southern Africa to new high-yielding varieties, which on average outyield traditional varieties by 40–50 percent even without fertilizer....Though these maize-breeding efforts were an undeniable technical success, broader efforts to support national production growth proved fiscally unsustainable, and once heavy subsidies were withdrawn, production fell (see table). This qualified success story reveals important lessons about both the strengths and pitfalls of past agricultural development efforts in Africa." From Text.

    An x ray photoelectron spectroscopy study of Au(x)In(y) alloys

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    Four gold-indium alloys were studied by x ray photoelectron spectroscopy. The binding energies and intensity ratios of the Au 4f7/2 and In 3d5/2 core levels were determined for the bulk alloy compositions of Au(10 percent In), Au3In, AuIn, and AuIn2. These values were determined for the native oxides on the materials, for the surfaces prepared by ion bombardment to remove the oxide and for surfaces scraped in-situ with a ceramic tool to expose the bulk composition. These results furnish calibration values that allow determination of the composition of thin films of this alloy system. In addition the binding energies add to the data base for understanding the effect of alloying on core level binding energies. As an illustration, these results are used to determine the composition of a series of alloy films formed by incongruent evaporation of an alloy charge

    Access to Land and Poverty Reduction in Rural Zambia: Connecting the Policy Issues

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    Key Policy Message: - Despite having relatively low population densities, inadequate access to land is one of the major causes of rural poverty in Zambia. - The apparent paradox of inadequate access to land for many rural households in a country of low population density is partially reconciled when taking into account that economically viable arable land requires at least some degree of access to basic services, water, road infrastructure, and markets. The basic public investments to make settlement economically viable have yet been made in many areas of Zambia. - Depending of future land allocation policy, access to good quality land with a market potential may become increasingly beyond the reach of many small-scale farm households, making it more difficult to achieve a smallholder-led, pro-poor agricultural development trajectory.zambia, food security, land, policy, Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics, Food Security and Poverty, Land Economics/Use, q18, q15,

    Marketing Policy Options for Consumer Price Mitigation Actions in the 2008/09 Maize Marketing Season in Zambia.

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    1) Maize prices are rising rapidly in 2008 and are fast approaching import parity levels. 2) Maize traders, millers and farmers all agree that Zambia will likely require imports by early 2009 in order to avoid domestic maize supply shortages. 3) Official food balance sheets appear to have underestimated the demand for maize this year. They may also have slightly overestimated the size of the 2007/08 maize crop. Hence the slow government recognition of the need for maize imports. 4) As of late September 2008, neither the Government of Zambia (GRZ) nor the private sector have arranged to import maize from South Africa. Trade sources suggest informal imports from Tanzania are helping to relieve the likely shortfall. 5) Zambian policy makers face a delicate balancing act: they need to maintain remunerative prices for farmers, in order to stimulate maize supply response during the coming 2008/09 production season, while at the same time moderating maize meal price increases to protect urban consumers and the many rural households who are net buyers of maize. 6) The time to respond to this balancing act challenge is now rather than later in the marketing season when costs of supplies and transport will increase. 7) Several policy actions offer potential win/win options for balancing these twin concerns:food security, food policy, Zambia, maize, marketing, Crop Production/Industries, Q20,

    Anticipating and Responding to Drought Emergencies in Southern Africa: Lessons from the 2002-2003 Experience

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    This paper examines the efficiency and effectiveness of emergency response in southern Africa through the lens of the 2002/03 food crisis in the region. The authors outline improvements in information and operational procedures needed to enhance the response to future events. They also discuss national and regional trade regime changes that would reduce the need for emergency response, and consider what lessons the 2002/03 crisis may have for the role of Strategic Grain Reserves (SGRs).food security, drought, emergency, Southern Africa, Food Security and Poverty, Q18,

    Market-Oriented Strategies to Improve Household Access to Food: Experience from Sub-Saharan Africa

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    The objectives of this report are to identify market-oriented strategies to alleviate both chronic and transitory food insecurity, and to examine the interactions between short-run targeting mechanisms and longer-run strategies designed to alleviate the chronic causes of inadequate access to food. The main premise of the report is that sustained improvements in household access to food in Sub-Saharan Africa require the development of more reliable food and input markets that (a) create incentives to adopt cost-reducing investments at various stages in the food system; and (b) offer incentives for rural households to shift from a subsistence-oriented pattern of production and consumption to more productive systems based on specialization and gains from exchange. Sustained productivity growth in most parts of the world has typically entailed some form of structural transformation, which, in the historical development processes of other regions, has been a prerequisite for broad-based and sustained growth in productivity, real incomes and purchasing power throughout society. Structural transformation involves a movement away from subsistence-oriented, household-level production toward an integrated economy based on specialization and exchange. But specialization makes households dependent on the performance of exchange systems. The ability to capture the productivity gains from new technology and specialization thus depends on reducing the risks and uncertainty of market-based exchange, thereby facilitating greater participation in the types of specialized production and consumption patterns involved in the process of structural transformation. Section 3 presents empirical evidence from research conducted in Africa to draw conclusions about how the design of agricultural policies and transfer programs have affected household access to food in both rural and urban areas. Based on the foregoing, section 4 presents the following guidelines for the design of strategies to promote access to food in Africa: (1.) Focus on achieving productivity gains in the food system. (2.) Focus on how food and income transfer programs can be designed to promote the long-run development of the food system- the basis for providing food for most people over the long run in addition to providing food to people in the short run. (3.) Focus on reducing consumer food costs by expanding the range of products available to produce and consume. (4.) Focus on the cost and reliability of food supplies to rural areas as a component of non-farm, livestock, and other income diversification strategies designed to promote access to food over the longer run. (5.) Focus on developing local analytical expertise to help guide food system development.Food Security and Poverty, Downloads July 2008-June 2009: 12,

    Secondary organic aerosol formation from in-use motor vehicle emissions using a potential aerosol mass reactor.

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    Secondary organic aerosol (SOA) formation from in-use vehicle emissions was investigated using a potential aerosol mass (PAM) flow reactor deployed in a highway tunnel in Pittsburgh, Pennsylvania. Experiments consisted of passing exhaust-dominated tunnel air through a PAM reactor over integrated hydroxyl radical (OH) exposures ranging from ∼ 0.3 to 9.3 days of equivalent atmospheric oxidation. Experiments were performed during heavy traffic periods when the fleet was at least 80% light-duty gasoline vehicles on a fuel-consumption basis. The peak SOA production occurred after 2-3 days of equivalent atmospheric oxidation. Additional OH exposure decreased the SOA production presumably due to a shift from functionalization to fragmentation dominated reaction mechanisms. Photo-oxidation also produced substantial ammonium nitrate, often exceeding the mass of SOA. Analysis with an SOA model highlight that unspeciated organics (i.e., unresolved complex mixture) are a very important class of precursors and that multigenerational processing of both gases and particles is important at longer time scales. The chemical evolution of the organic aerosol inside the PAM reactor appears to be similar to that observed in the atmosphere. The mass spectrum of the unoxidized primary organic aerosol closely resembles ambient hydrocarbon-like organic aerosol (HOA). After aging the exhaust equivalent to a few hours of atmospheric oxidation, the organic aerosol most closely resembles semivolatile oxygenated organic aerosol (SV-OOA) and then low-volatility organic aerosol (LV-OOA) at higher OH exposures. Scaling the data suggests that mobile sources contribute ∼ 2.9 ± 1.6 Tg SOA yr(-1) in the United States, which is a factor of 6 greater than all mobile source particulate matter emissions reported by the National Emissions Inventory. This highlights the important contribution of SOA formation from vehicle exhaust to ambient particulate matter concentrations in urban areas

    Smallholder Income and Land Distribution in Africa: Implications for Poverty Reduction Strategies

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    This paper provides a micro-level foundation for discussions of income and asset allocation within the smallholder sector in Eastern and Southern Africa, and explores the implications of these findings for rural growth and poverty alleviation strategies in the region. Results are drawn from nationally-representative household surveys in five countries between 1990 and 2000: Ethiopia, Kenya, Rwanda, Mozambique, and Zambia. The paper addresses five major points: (1) why geographically-based poverty reduction or targeting strategies-e.g., focusing on marginal areas-is likely to miss a significant share of the poor in any particular country regardless of targeting efficiency in these areas; (2) why current enthusiasm for community-driven development approaches will require serious attention to how resources are allocated at local levels; (3) why sustained income growth for the poorest strata of the rural population will depend on agricultural growth in most countries, even though the poor generally lack the land and other productive resources to respond directly or immediately to policies and investments to stimulate agricultural growth; (4) why agricultural productivity growth, while most easily generating gains for better-off smallholder farmers, is likely to offer the best potential for pulling the poorest and land-constrained households out of poverty; and (5) why meaningful poverty alleviation strategies in many countries will require fundamental changes to make land more accessible to smallholder farmers. This could be accomplished through various processes, including improvement in land rental markets or perhaps land redistribution. We briefly elaborate on each of these findings.Food Security and Poverty, Land Economics/Use,
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