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Long-term changes in land use, climate, and agricultural technologies may affect pest severity and management. The influences of these major drivers can only be identified by analyzing long-term data. This study examines panel data on land use, adoption of genetically modified Bacillus thuringiensis (Bt) insect-resistant cotton, weather, pest severity, and insecticide use on three major cotton pests for 51 counties in China during 1991-2015. Bt cotton had pervasive effects on the whole pest complex in cotton and its management. Adoption resulted in major reductions in insecticide use for bollworm control. The resulting restoration of aphid biological control decreased aphid severity. However, mirid bugs, which have few effective natural enemies in cotton, increased in severity with warming May and reduced insecticide spraying against bollworm. The effects of landscape on pest severity were pest specific. The severity of cotton aphid and mirid bugs decreased with higher land use diversity, but the severity of highly polyphagous cotton bollworm was unrelated to land use diversity. Shares of forest, water body, and unused land area were negatively associated with the severity of mirid bugs, whereas cotton bollworm responded positively to the shares of water body and unused land area. Farmers sprayed insecticides at mild infestation levels and responded aggressively to severe bollworm outbreaks. Findings support the usefulness of Bt-based plant resistance as a component of integrated pest management (IPM) but highlight the potential for unexpected outcomes resulting from agro-ecosystem feedback loops as well as the importance of climate.
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Agricultura , Bacillus thuringiensis/genética , Gossypium/genética , Controle Biológico de Vetores/métodos , Tempo (Meteorologia) , Animais , Afídeos , Inseticidas/farmacologia , MariposasRESUMO
We use IFPRI's IMPACT framework of linked biophysical and structural economic models to examine developments in global agricultural production systems, climate change, and food security. Building on related work on how increased investment in agricultural research, resource management, and infrastructure can address the challenges of meeting future food demand, we explore the costs and implications of these investments for reducing hunger in Africa by 2030. This analysis is coupled with a new investment estimation model, based on the perpetual inventory methodology (PIM), which allows for a better assessment of the costs of achieving projected agricultural improvements. We find that climate change will continue to slow projected reductions in hunger in the coming decades-increasing the number of people at risk of hunger in 2030 by 16 million in Africa compared to a scenario without climate change. Investments to increase agricultural productivity can offset the adverse impacts of climate change and help reduce the share of people at risk of hunger in 2030 to five percent or less in Northern, Western, and Southern Africa, but the share is projected to remain at ten percent or more in Eastern and Central Africa. Investments in Africa to achieve these results are estimated to cost about 15 billion USD per year between 2015 and 2030, as part of a larger package of investments costing around 52 billion USD in developing countries.
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This paper explores the impacts of a water right's allocative priority-as an indicator of farmers' risk-bearing ability-on land irrigation under water supply uncertainty. We develop and use an economic model to simulate farmers' land irrigation decision and associated economic returns in eastern Idaho. Results indicate that the optimal acreage of land irrigated increases with water right priority when hydroclimate risk exhibits a negatively skewed or right-truncated distribution. Simulation results suggest that prior appropriation enables senior water rights holders to allocate a higher proportion of their land to irrigation, 6 times as much as junior rights holders do, creating a gap in the annual expected net revenue reaching up to $141.4 acre-1 or $55,800 per farm between the two groups. The optimal irrigated acreage, expected net revenue, and shadow value of a water right's priority are subject to substantial changes under a changing climate in the future, where temporal variation in water supply risks significantly affects the profitability of agricultural land use under the priority-based water sharing mechanism.
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In 2017-2018, a group of international development funding agencies launched the Crops to End Hunger initiative to modernize public plant breeding in lower-income countries. To inform that initiative, USAID asked the International Food Policy Research Institute and the United States Department of Agriculture's Economic Research Service to estimate the impacts of faster productivity growth for 20 food crops on income and other indicators in 106 countries in developing regions in 2030. We first estimated the value of production in 2015 for each crop using data from FAO. We then used the IMPACT and GLOBE economic models to estimate changes in the value of production and changes in economy-wide income under scenarios of faster crop productivity growth, assuming that increased investment will raise annual rates of yield growth by 25% above baseline growth rates over the period 2015-2030. We found that faster productivity growth in rice, wheat and maize increased economy-wide income in the selected countries in 2030 by 59 billion USD, 27 billion USD and 21 billion USD respectively, followed by banana and yams with increases of 9 billion USD each. While these amounts represent small shares of total GDP, they are 2-15 times current public R&D spending on food crops in developing countries. Income increased most in South Asia and Sub-Saharan Africa. Faster productivity growth in rice and wheat reduced the population at risk of hunger by 11 million people and 6 million people respectively, followed by plantain and cassava with reductions of about 2 million people each. Changes in adequacy ratios were relatively large for carbohydrates (already in surplus) and relatively small for micronutrients. In general, we found that impacts of faster productivity growth vary widely across crops, regions and outcome indicators, highlighting the importance of identifying the potentially diverse objectives of different decision makers and recognizing possible tradeoffs between objectives.
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Produtos Agrícolas , Modelos Econômicos , Produção Agrícola , Países em Desenvolvimento , Abastecimento de Alimentos , Humanos , Oryza/crescimento & desenvolvimento , Triticum/crescimento & desenvolvimento , Estados Unidos , United States Agency for International DevelopmentRESUMO
Global food security will remain a worldwide concern for the next 50 years and beyond. Recently, crop yield has fallen in many areas because of declining investments in research and infrastructure, as well as increasing water scarcity. Climate change and HIV/AIDS are also crucial factors affecting food security in many regions. Although agroecological approaches offer some promise for improving yields, food security in developing countries could be substantially improved by increased investment and policy reforms.
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Agricultura , Abastecimento de Alimentos , Alimentos , Política Pública , Síndrome da Imunodeficiência Adquirida/epidemiologia , Biotecnologia , Clima , Conservação dos Recursos Naturais , Países em Desenvolvimento , Ecossistema , Educação , Saúde Global , Humanos , Pobreza , Pesquisa , População Rural , Abastecimento de ÁguaRESUMO
This report describes past trends in global child malnutrition and assesses future prospects for reducing child malnutrition. Most developing countries have significantly reduced the proportion of malnourished children during the past three decades. However, because of population growth, the absolute number of malnourished children has fallen much less sharply. Moreover, the number of malnourished children has increased in Sub-Saharan Africa. A global food supply-and-demand model is used to project child malnutrition to 2020 under alternative assumptions on policies and investments that influence food security outcomes in education, clean water, agricultural research, irrigation and rural infrastructure. The baseline "best-estimate" projection shows that the number of malnourished children will continue to decline slowly but that child malnutrition will continue to increase in Sub-Saharan Africa. The optimistic scenario shows that better policy and more rapid economic and agricultural growth can lead to substantial food security improvements, but the pessimistic scenario shows that significantly worse outcomes are also possible with relatively small declines in policy and investment efforts relative to the baseline. A concerted effort to eliminate childhood malnutrition would require policy reform and significant increases in public investment to produce long-term gains in income growth, agricultural productivity and social indicators.
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Abastecimento de Alimentos/economia , Investimentos em Saúde/tendências , Distúrbios Nutricionais/prevenção & controle , Política Nutricional/tendências , Criança , Países em Desenvolvimento , Humanos , Investimentos em Saúde/economia , Modelos Estatísticos , Distúrbios Nutricionais/epidemiologiaRESUMO
Aborda el tema de la agricultura como fuente de remedio para la nutrición y la seguridad alimentaria juntamente con los Objetivos del Desarrollo del Milenio. Documento en formato PDF, requiere Acrobat Reader.