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1.
Dry‐land legumes, well adapted to drought‐prone areas, have largely been neglected in the past despite the good opportunities they offer for income growth and food (and nutritional) security for the poor. This study evaluated the adoption and impact of two farmer and market‐preferred and disease‐resistant pigeonpea varieties that were developed and promoted in semi‐arid Tanzania. The new varieties were resistant to fusarium wilt, a fungal disease devastating the crop. However, farmers wanting to adopt new varieties did not adopt due to seed access constraints and under‐developed seed delivery systems. Adoption of new varieties is therefore analyzed using an augmented double hurdle model that allows estimating variety adoption conditional on seed access thresholds accounting for the additional information on sample separation. The study identifies the crucial role of seed access (local supply), extension, education, participatory decision making, capital, and household assets in determining adoption. The social economic benefits of the technology and policies for improved seed access were further analyzed using the extended economic surplus method (DREAM model). Even under restrictive assumptions, overall discounted benefits were found to be quite attractive, indicating the need for additional efforts to scale‐up the success story. Analysis of changes in research benefits from relaxing the seed access constraint showed that net gains would increase by up to 30% if farmer access to improved seeds can be assured. Smallholder farmers are the major beneficiaries along with consumers and rural net‐buyers who gain from productivity‐induced lower market prices.  相似文献   

2.
This paper investigates the impact of genetically engineered (GE) varieties on the cost structure of corn and soybean production in Canada. Employing an adoption index for each farm and a time trend with farm‐level data on production costs of grain corn and soybeans from 2000 to 2007, a translog cost function and the associated input‐share equations are estimated. The use of the adoption index improves the estimates of technological change and multifactor productivity (MFP) growth. The results demonstrate that the adoption of GE corn and soybean reduced the variable costs of production by 0.62% per year. The MFP of corn and soybean grew by 2.0% per year during the study period, and 31% of this growth is attributable to GE varieties of these crops. The results also reveal that the adoption of GE varieties reduced the cost shares of fertilizer, herbicides and pesticides, and machinery in corn and soybean production. While the adoption of GE varieties increased the cost shares of seeds and custom works including labor, only the former was statistically significant.  相似文献   

3.
There is a lack of evidence for impact at scale of vegetable research and development, although the importance of vegetables for human nutrition and smallholder incomes is generally understood. We therefore study adoption and impact of improved tomato and African eggplant varieties developed through international agricultural research, released by national agricultural research and extension systems, and supplied to farmers by private seed companies in East and Southern Africa from 1990 to 2014. The study finds that in 2014, varieties developed by the World Vegetable Center accounted for 50% of tomato and 98% of African eggplant commercial seed production in East and Southern Africa. For Tanzania alone, investment in crop improvement generated economic gains of US$ 255 million for tomato and US$ 5 million for African eggplant up to 2014. The internal rate of return is 26% for tomato and 12% for African eggplant, though we project the latter to increase to 26% by 2024 as the variety was released only in 2007. These findings support the view that agricultural policy and investment reoriented towards contemporary nutritional challenges will give high returns to investment.  相似文献   

4.
In this article, the potential impacts of Bt eggplant technology in Indian agriculture are analyzed. Several proprietary Bt hybrids are likely to be commercialized in the near future. Based on field trial data, it is shown that the technology can significantly reduce insecticide applications and increase effective yields. Comprehensive farm-survey data are used to project farm-level effects and future adoption rates. Simulations show that the aggregate economic surplus gains of Bt hybrids could be around US$108 million per year. Consumers will capture a large share of these gains, but farmers and the innovating company will benefit too. As the company has also shared its technology with the public sector, Bt open-pollinated varieties might become available with a certain time lag. This would make the technology more accessible, especially for resource-poor farmers, entailing further improvements in welfare and distribution effects. The wider implications of the private–public technology transfer are discussed. Furthermore, the potential benefits for farmers' health resulting from reduced insecticide applications are examined, using an econometric model and a cost-of-illness approach. These benefits are worth an additional $3–4 million per year, yet they constitute only a small fraction of the technology's environmental and health externalities. More research is needed for comprehensive impact analysis.  相似文献   

5.
Cowpea covers the largest area of any grain legume in Africa and is especially important in West Africa where Nigeria and Niger alone account for over 75% of the total cowpea production in the world. Despite successes of international and national cowpea improvement research in the development and release of several improved varieties, there is limited empirical evidence of adoption and ex-post impacts of improved cowpea. Using a nationally representative survey data from a sample of 1,525 cowpea-growing households in northern Nigeria cultivating over 2,500 cowpea plots, we assess the adoption and impacts of improved cowpea varieties on cowpea yields, net returns and production costs. We apply a control function approach and propensity score matching models to estimate the causal effects of adoption of improved cowpea varieties . Our results show that 38% of the cowpea plots were planted with improved varieties, and cowpea yields, net returns and production costs increase significantly with the adoption of improved cowpea varieties. Adoption of improved cowpea varieties is associated on average with 26% yield gains, 61% increase in net returns and 14% increase in production costs. We also show that farmers who have a lower propensity to adopt improved cowpea varieties also face higher costs of production.  相似文献   

6.
基于改进的农业生态区法的中国耕地粮食生产潜力评价   总被引:32,自引:3,他引:32  
研究目的:发展适合于中国的农业生态区(AEZ)方法,并应用于全国耕地粮食生产潜力评价的实践.研究方法:农业生态区法.研究结果:在2000年投入水平下的全国耕地粮食生产潜力为食用粮58984.28万吨,油料3017.76万吨,糖料9744.46万吨.研究结论:AEZ是宏观尺度土地生产潜力评价的有效方法.受基础数据精度、评价参数适用性等影响,评价的结果仍然有待于进一步验证.  相似文献   

7.
A 2012 survey of upland U.S. cotton producers was analyzed to determine the factors contributing to changes in weed management costs (WMCs) after the identification of herbicide‐resistant weeds. An ordered probit regression estimated changes in WMC as a first‐order Markov process. The most important determinants of post‐resistance cost increases were initial WMCs, adoption of labor‐intensive remedial practices, and wick application of herbicides. Cultivation and mechanical/chemical‐intensive practices did not increase WMCs. Post‐resistance changes in WMC ranged between $85 and $138 ha?1, depending on the practices adopted. WMCs increased by $88 ha?1 when cost‐neutral practices were adopted. The in‐sample aggregate costs of managing herbicide resistance ranged between $25 and $53 million, depending on the types of adopted practices.  相似文献   

8.
The profitability of anaerobic digesters (ADs) for Ontario dairy farmers are examined using real options under current and proposed government pricing policies and investment uncertainty. In the case of a renewable energy initiative such as an AD with large sunk costs and volatile returns, the value of deferring investment may be significant enough to offset the returns suggested by the net present value (NPV) approach. For a 150 cow herd, net revenues should be approximately $1.1 million before the AD is installed using the real options approach as compared to $0.5 million with the NPV approach. An AD is close to generating a positive NPV for a 600 cow herd if for either a 1% increase in the electrical price or decrease in the cost. However, farmers need not invest today and there is a value to delaying this decision from potential improvements in the technology that increase the efficiency and/or decrease operating costs of the AD. The real options analysis indicates that this option to delay investment has a value of approximately $300,000 for a typical Ontario dairy farm. Thus, either significant grant funding or higher feed‐in‐tariff rates are required to induce the increased adoption of AD technology in Ontario today even for the largest of dairy farms. Considering the probability of government support potentially ending, increases the value of investing today but a significant option value to defer still exists.  相似文献   

9.
The major biotic constraints to the production of maize, the major staple food in Western Kenya, are field pests such as Striga and stem borers, and low soil fertility. To counter these constraints, new cropping systems have been developed, including “push‐pull,” rotations with promiscuous soybean varieties and green manure crops, and imidazolinone resistant‐ (IR‐) maize. To analyze the technical and economic performance of these technologies, both with and without fertilizer, on‐farm researcher‐managed long‐term trials were implemented over six seasons in two sites each in Vihiga and Siaya districts of Western Kenya. The economic results, based on marginal analysis using a multioutput, multiperiod model, show that the new cropping systems with fodder intercropping (push‐pull) or soybean rotations were highly profitable. Push‐pull is more profitable but requires a relatively high initial investment cost. Green manure rotation, IR‐maize, and fertilizer all increased yields, but these investments were generally not justified by their increased revenue. We argue that research on rotation and cropping systems to tackle pest and soil fertility problems in Africa deserve more attention. This will require increased collaboration between agronomists and economists to set up long‐term experiments with new cropping systems to develop proper economic models.  相似文献   

10.
In this study we assessed the potential of woody biomass (short-rotation Mallee Eucalypts) for renewable energy generation as an economically viable way of motivating widespread natural resource management under climate change in the 11.9 million ha Lower Murray agricultural region in southern Australia. The spatial distribution of productivity of agricultural crops and pasture, and biomass was modelled. Average annual economic returns were calculated under historical mean (baseline) climate and three climate change scenarios. Economically viable areas of biomass production were identified where the profitability of biomass is greater than the profitability of agriculture under each scenario for three factory gate biomass prices. The benefits of biomass production for dryland salinisation, wind erosion, and carbon emissions reduction through biomass-based renewable energy production were also modelled. Depending on climate scenario, at the median price assessed ($40/tonne) biomass production can generate $51.4–$88 M in annual net economic returns, address 41,226–165,577 ha at high risk of dryland salinisation and 228,000–1.4 million ha at high risk of wind erosion, and mitigate 10.4–12 million tonnes of carbon (CO2−e) emissions annually. Economically viable areas for biomass production expanded under climatic warming and drying especially in more marginal agricultural land. Under the baseline, the area at high risk of dryland salinisation was more than double that at high risk of wind erosion. However, under climatic warming and drying the relative importance of these two natural resource management objectives switched with the area at high risk of wind erosion becoming much larger. As biomass production can achieve multiple natural resource management objectives, it may provide a land use policy option that is adaptable to changing priorities and economically resilient given climatic uncertainties. For such a significant and enduring land use change policy it is prudent to assess both the economic and environmental potential under climate change.  相似文献   

11.
The spatial distribution of modern varieties, and the genes they embody, has economic value because it affects crop productivity from year to year. Since farmers choose varieties based on observable traits rather than the genes they cannot see, a first step in understanding the spatial distribution of genes is to better understand the determinants of the spatial distribution of varieties. In this paper, we have constructed spatial diversity indices from area distributions of modern wheat varieties in Australia and China. We hypothesise that factors explaining variation in these indices are related to farmers' demand for traits and the supply of varieties, given physical features of the production environment. We test these hypotheses using reduced form equations for three concepts of spatial diversity, richness, abundance and evenness, using Zellner's seemingly unrelated regression (SUR). Spatial diversity indicators and analyses of this type, if more fully developed and targeted to address specific policy issues, may assist in monitoring crop genetic diversity or ‘refuge’ targets associated with the diffusion of some genetically modified crops.  相似文献   

12.
We develop a mathematical programming model for the analysis of a nationwide waste‐management system based on composting of organic wastes. The model integrates a wide range of engineering, environmental, and economic factors, including estimated production functions based on agronomic experimental data, as well as demand functions for vegetative agricultural products. The model is applied to the case of Israel, comprising 14 groups of municipalities as the source of organic municipal solid waste and wastewater‐treatment sludge, 8 composting plants, and 13 agricultural regions; the latter constitute the source of livestock manure and are the consumers of compost to be potentially applied to 42 crops. From a social point of view, 90% of the compost's potential production was found to be warranted. This efficient solution, however, does not emerge under the base‐year‐observed situation, largely because of the absence of source separation of organic municipal solid waste and the farmers' lack of awareness of compost's advantages as a substitute for conventional fertilizers and as a soil‐amending product. Consequently, most of the organic wastes are disposed of by landfilling, resulting in a loss of $102 million per year in terms of net social benefits. While the consumers of agricultural products are expected to benefit from a shift from the base‐year situation to the efficient solution, most of their gain is expected to come at the expense of the farming sector. Nevertheless, the appearance of the efficient solution does not depend on administrative compensation payments, but on the removal of bottlenecks. Potential government intervention strategies to promote the change are analyzed.  相似文献   

13.
The economic impact of bean disease resistance research in Honduras   总被引:2,自引:0,他引:2  
This paper presents evidence of recent adoption rates of disease resistant bean varieties (RVs), the farm‐level benefits of RV adoption, and the ex post rate of return to disease resistant bean research in Honduras. Results from a farm‐level survey in 2001 in the two principal bean‐producing regions of the country show that 41–46% of bean farmers (depending upon the season) have adopted an RV, and that adoption is neutral with respect to farm‐size and market orientation. An expected utility framework was used to estimate the farm‐level benefits of RV adoption, using a combination of experimental trial and farm‐level survey data. Adopters gain the equivalent of 7–16% (depending on the variety) in bean income from the yield loss averted through RV use. The ex post rate of return to disease resistant bean research in Honduras from 1984 to 2010 is 41.2%.  相似文献   

14.
This paper reports the results of a study undertaken to estimate the economic impact in developing countries of efforts by the International Maize and Wheat Improvement Center (CIMMYT) to breed leaf rust resistant spring bread wheat varieties since 1973. The challenge in estimating these benefits lies in the pathogen's ability to mutate to new races, which may infect previously resistant varieties. Genetic resistance, rather than fungicide application, is the principal means of controlling leaf rust in developing countries. Whereas productivity enhancement is often estimated in terms of yield gains and increased supply, productivity maintenance is measured in terms of the yield losses avoided by the research investment. The internal rate of return on CIMMYT's research investment was estimated at 41%. When discounted by 5%, the net present value was US$ 5.36 billion in 1990 dollars, and the benefit‐cost ratio was 27:l. These findings emphasise the economic importance of maintenance research in crop breeding programs.  相似文献   

15.
Adoption of improved maize varieties in the hills of Nepal   总被引:3,自引:0,他引:3  
Maize (Zea mays L.) is the most important cereal crop in the hills of Nepal, where the grain is used for human consumption and the stover for animal fodder. Maize farms are small, and population pressure necessitates the intensification of existing farming systems. Maize research directed at developing technologies for maize production began in Nepal in 1965. In 2000, a survey was carried out in two districts to determine the current level of adoption of improved maize production practices. In each of these districts, remote and accessible village development committees (VDCs) were surveyed. Questionnaires were administered to 54 randomly selected households in each VDC. A Tobit analysis was used to determine socio‐economic, physical and technology factors that influence the use of improved varieties by farmers. All households use composted farmyard manure, and in the more accessible areas, urea as part of their soil fertility management strategy. Use of improved varieties was less than 60% for all VDCs and only 15% in the most remote VDC. In three of the four VDCs, adoption of improved varieties primarily occurred during the past 5 years. Based on a Tobit analysis, Khet land area, ethnic group, years of fertiliser use, off‐farm income, and contact with extension significantly and positively affected adoption of improved varieties. Farmers in VDCs in central Nepal reported lack of seed to be the major constraint to the adoption of improved varieties, while lack of knowledge of new varieties was the major constraint for farmers in the western VDCs. The results from this survey suggest that the strategy for improving the adoption of new varieties will differ depending on infrastructure and the socio‐economic conditions of the farmers in a given area.  相似文献   

16.
This study evaluates the impact of a long‐term research collaboration between the Senegalese Institute for Agriculture Research (ISRA), and the Bean/Cowpea Collaborative Research Support Program (CRSP) funded by the U.S. Agency for International Development (USAID). Adoption of the primary outputs from this collaboration, a nonchemical cowpea storage method and two short‐season cowpea varieties, were tracked through a series of farmer interviews in 1996, 1997, and 2004 in the main cowpea growing area of Senegal. Combined with information from an impact assessment in the late 1980s, this study draws on ex‐post adoption data from most of the product life cycle for the storage technology. The 2004 survey found that 60.4% of cowpea production in the main cowpea growing area of Senegal is stored in metal drums and that 69% of households use this storage technology; ISRA/CRSP improved short season varieties were determined to account for 3.6% of cowpea production. Baseline economic analysis of the most recent survey data, which includes benefits and costs of the storage technology and improved varieties, reveal an IRR to donor funding of 13%. The benefits of these technologies appear to be evenly distributed in the rural population on the basis of gender and ethnic background. Comparison of the rates of technology adoption over time, however, reveals that use of the storage technology may be decreasing; inclusion of this technology disadoption trend reduces the IRR by only 0.4% from the baseline estimate. Overall, estimated returns reveal that this collaboration has been a good investment for the U.S. and Senegalese governments, and other donors.  相似文献   

17.
Regional trade agreements are the dominant arrangement for economic integration. What does a dual membership mean for countries participating in multiple regional negotiations? We address the question from the perspective of tea exporters in Vietnam, a member of both the Trans‐Pacific Partnership (TPP) and the Regional Comprehensive Economic Partnership (RCEP). Focusing on the removal of tariffs and the cooperation on pesticide residue standards, we find that the TPP agreement will raise Vietnam's tea exports by about $4 million a year if TPP endorses Codex standards. However, Vietnamese tea exports will decline if TPP endorses American standards, unless sufficient technical assistance is provided. After the RCEP agreement takes effect, tea exporters from China and India will further penetrate the TPP markets by re‐exporting from Vietnam.  相似文献   

18.
This paper addresses the prospects for technical change in the irrigated rice sector of Senegal, and measures ex‐ante the economic returns to recent research efforts. In 1994, three new rice varieties were released to farmers in the Senegal River Valley (SRV), the major irrigated rice region in Senegal. The productivity advantage of the new varieties is based primarily on early maturity, which permits double‐cropping. (The seeds are also higher yielding than existing cultivars.) We use a conventional [Akino and Hayami (1975), Am. J. Agric. Econ. 57, 1–10] partial‐equilibrium model adapted to the Senegalese situation, to assess the social benefits of research and compare those to its costs in calculating the internal rate of return (IRR). To account for uncertainty regarding the future values of model variables we use simulation which allows us to generate a distribution of all possible outcomes of the IRR. We find that rice research is almost certain to have a very high payoff over the 1995–2004 period. The expected value of the IRR is calculated to be 121% per year, with a 97.5% probability that it lies above annual capital costs of 18%. ©2001 Elsevier Science B.V. All rights reserved.  相似文献   

19.
We examine whether a firm is more or less likely to adopt precision technology when input prices are stochastic. The results are important to determining whether programs and contracts that reduce input price uncertainty may deter the adoption of conservation practices. An economic model of the technology adoption decision shows that the net effect of input price risk is ambiguous and depends on several factors including the shutdown effect, the mean price effect, the precision expansion effect, and the risk aversion effect. An empirical implementation of the model relies on data on water price and irrigation technology adoption observed in a California irrigation district over the period 1999–2002. The results show that a stable input price increases the adoption of precision technology, but the impact depends on crop choice and land quality characteristics.  相似文献   

20.
Roundup Ready® Wheat (RRW) is one of the first geneticallymodified (GM) traits for the wheat sector. We develop a spatialpartial equilibrium model of the higher-protein hard wheat marketand assess the changes in the distribution of welfare associatedwith release and adoption of RRW. It incorporates segments forGM aversion in each market and segregation costs for each segment.In the most likely scenario, producer and consumer welfare increasesby $301 and $252 million, respectively. Producers of hard redspring wheat in the US and Canada gain. There are welfare lossesto hard red winter wheat growers in the US and to EU consumerswho have to import at a higher cost.  相似文献   

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