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China was the first developing country to introduce Bt cotton on a large scale. This paper provides an indepth economic analysis of Bt cotton production by small-scale farmers in China. Data were collected in 2002 in Linqing County, in Shandong Province and comprised a season-long cotton production monitoring with 150 farmers and complementary household interviews. For quality assessment, the Bt toxin concentration of the various Bt varieties used by the farmers was determined for each plot. All farmers were growing insect resistant Bt cotton varieties. Yet, they sprayed high amounts of chemical insecticides, out of which 40% were extremely or highly hazardous. The paper reviews methodological issues inherent to impact assessment of crop biotechnology and identifies market and institutional failure as possible reasons for continued high pesticide use. Using the damage function methodology the coefficients for both damage control inputs, i.e., Bt varieties (measured as toxin concentration), and insecticide quantity were not significantly different from zero. Results show that absence of enabling institutions and lack of farmer knowledge can considerably limit the benefits of Bt cotton for small-scale farmers. The paper points out the importance to include the institutional conditions in the evaluation of agricultural biotechnology in developing countries.  相似文献   

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A study of the commercial growing of Bacillus thuringiensis (Bt) cotton in India, compares the performance of over 9,000 Bt and non-Bt cotton farm plots in Maharashtra over the 2002 and 2003 seasons. Results show that since their commercial release in 2002, Bt cotton varieties have had a significant positive impact on average yields and on the economic performance of cotton growers. Regional variation showed that, in a very few areas, not all farmers had benefited from increased performance of Bt varieties.  相似文献   

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There is a broad literature on the impact of Bt cotton adoption in different countries, but few studies have explicitly looked at environmental and health effects from an economic perspective. We analyse the impact of Bt cotton on environmental efficiency in Pakistan, using farm survey data and a doubly heteroskedastic stochastic production function framework. Negative environmental and health effects of chemical pesticide use are quantified with the environmental impact quotient. Bt‐adopting farms have higher cotton yields, while using lower pesticide quantities and causing less environmental damage. Bt farms are both technically and environmentally more efficient than non‐Bt farms. Bt adoption increases environmental efficiency by 37%. Achieving the same reduction in negative environmental and health impact without Bt would cost conventional cotton farmers US$ 54 per acre in terms of foregone yields and revenues (7% of total revenues). Extrapolating this shadow price of the technology's health and environmental benefits to the total Bt cotton area in Pakistan results in an aggregate value of US$ 370 million. These benefits are in addition to the profit gains for Bt‐adopting farmers. Our results suggest that Bt technology can contribute to sustainable agricultural development.  相似文献   

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Bt cotton remains one of the most widely grown biotech crops among smallholder farmers in lower income countries, and numerous studies attest to its advantages. However, the effectiveness of Bt toxin, which depends on many technical constraints, is heterogeneous. In Pakistan, the diffusion of Bt cotton occurred despite a weak regulatory system and without seed quality control; whether or not many varieties sold as Bt are in fact Bt is also questionable. We utilise nationally representative sample data to test the effects of Bt cotton use on productivity. Unlike previous studies, we invoke several indicators of Bt identity: variety name, official approval status, farmer belief, laboratory tests of Bt presence in plant tissue, and biophysical assays measuring Bt effectiveness. Only farmer belief affects cotton productivity in the standard production model, which does not treat Bt appropriately as damage‐abating. In the damage control framework, all Bt indicators reduce damage from pests. Biophysical indicators have the largest effect and official approval has the weakest. Findings have implications for impact measurement. For policy‐makers, they suggest the need, on ethical and productivity grounds, to improve variety information and monitor variety integrity closer to point of sale.  相似文献   

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This article examines the ecosystem impacts of transgenic Bt cotton technology resulting from reduced chemical pesticide use. Employing unique panel data from smallholder farmers in India, negative environmental and health effects of pesticide use are quantified with the environmental impact quotient (EIQ), with and without Bt technology. An environmentally sensitive dynamic production function is estimated, treating the environmental risk of pesticide toxicity as an undesirable output in the production process. Negative externalities are significantly lower in Bt than in conventional cotton. The reduction in EIQ through Bt technology adoption has increased from 39 per cent during 2002–2004 to 68 per cent during 2006–2008. Bt adoption has also contributed to higher environmental efficiency. Environmental efficiency is influenced by the quality of Bt technology: high‐quality Bt seeds are associated with higher environmental efficiency than lower‐quality seeds.  相似文献   

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The short‐run impact of Bt cotton adoption has been well documented; however, the sustainability of the impact remains unclear. In particular, pest resistance build‐up and secondary pest outbreaks have caused concern regarding the sustainability of this benefit. This paper analyses the effects and impact dynamics of Bt cotton adoption in China. Using six unique waves of panel data collected between 1999 and 2007, we show that the benefits of Bt cotton continue 10 years after it has been commercialised, albeit with evidence of a decline in the benefit since the early adoption period. Importantly, we also show that the benefit has been shared by both Bt and non‐Bt cotton adopters.  相似文献   

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In the continuing debate over the impact of genetically modified (GM) crops on farmers of developing countries, it is important to accurately measure magnitudes such as farm‐level yield gains from GM crop adoption. Yet most farm‐level studies in the literature do not control for farmer self‐selection, a potentially important source of bias in such estimates. We use farm‐level panel data from Indian cotton farmers to investigate the yield effect of GM insect‐resistant cotton. We explicitly take into account the fact that the choice of crop variety is an endogenous variable which might lead to bias from self‐selection. A production function is estimated using a fixed‐effects model to control for selection bias. Our results show that efficient farmers adopt Bacillus thuringiensis (Bt) cotton at a higher rate than their less efficient peers. This suggests that cross‐sectional estimates of the yield effect of Bt cotton, which do not control for self‐selection effects, are likely to be biased upwards. However, after controlling for selection bias, we still find that there is a significant positive yield effect from adoption of Bt cotton that more than offsets the additional cost of Bt seed.  相似文献   

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新疆是我国最大的优质棉生产基地,目前初步形成了"世界棉花形势看中国,中国棉花市场看新"的格局,对保障国家棉花产业安全,促进新疆农业增效、农民增收和经济社会稳定发挥了重要作用。 近疆年来,新疆棉花生产成本不断上涨、国内外棉花价差巨大,棉农生产积极性急剧下降,国家棉花安全和棉农收益受到严重影响。发展计划司带队赴新疆博乐市达勒特镇呼热布呼村就"新疆棉花产业现代化道路该如何走"等相关问题进行调研。通过调研,调研组认为实现棉花生产全程机械化是降低棉花生产成本、实现棉花产业现代化、巩固新疆棉花产业优势地位的必然选择。呼热布呼村闯出了新路,主要通过以棉田改造为基础,推进棉花标准化种植、以机械采棉为突破口,推进棉花生产全程机械化、以技术推广服务为支撑,推进棉花社会化服务体系建设等5方面,实现棉花生产全程机械化、促进棉花产业现代化积累了经验。同时也分析了制约新疆棉花生产全程机械化的 5个重点环节,提出了进一步推进棉田改造、加强适应棉花机械化集成技术和品种研究、加大技术推广和培训力度等5方面来推进新疆棉花生产全程机械化的对策措施。  相似文献   

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Data from a farm survey and choice experiment are used to value the benefits of Bt cotton in Pakistan. Unlike previous research on the economic impacts of Bt, which mostly concentrated on financial benefits in terms of gross margins, we also quantify and monetize health and environmental benefits associated with technology adoption. Due to lower chemical pesticide use on Bt cotton plots, there are significant health advantages in terms of fewer incidents of acute pesticide poisoning, and environmental advantages in terms of higher farmland biodiversity and lower soil and groundwater contamination. Farmers themselves value these positive effects at US$ 79 per acre, of which half is attributable to health and the other half to environmental improvements. Adding average gross margin gains of US$ 204 results in aggregate benefits of US$ 283 per acre, or US$ 1.8 billion for the total Bt cotton area in Pakistan.  相似文献   

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[目的]近几年来,山东棉花生产严重衰退,同时伴生棉花生产布局的大幅调整和集中。需进一步探明相同的外部市场环境和类似的产业发展条件下,山东棉花衰退与集中的缘由。[方法]利用1995年、2005年、2015年山东主要植棉县的生产统计资料,计算规模优势指数、单产优势指数、集中度优势指数、综合优势指数,并对比测算结果与现实集中情况的匹配程度,证实山东省棉花生产的区域布局在不断优化,棉花生产逐渐向比较优势县(区)集中。[结果]山东棉花生产的衰退与集中符合区域棉花生产的比较优势,是农民根据棉花生产的市场机会、比较优势(古典比较优势和内生比较优势)和市场深化的宏观经济环境做出的理性选择。[结论]今后山东的棉花生产应有进有退,在生产优势县(区)实施更具针对性的棉花支持政策,加强对鲁西北盐碱地棉花育种与栽培技术的科研支持,缩小因自然因素导致的产量缺口,争取让国家目标价格政策覆盖到省内三大棉花优势区域,并在黄河三角洲设立国家级棉花生产保护区。  相似文献   

13.
New Rice for Africa (NERICA) was developed by the Africa Rice Center by crossing high-yielding Asian rice (Oryza sativa L.) with locally adapted African rice (Oryza glaberrima Steud.). Community-based seed production of NERICA varieties was introduced in a village in central Benin in 2006 through seed dissemination projects. It was reported that high-adoption rates of these varieties were mainly due to high demand by development projects for seed dissemination, and to incentives (i.e. selling the rice seed at a higher than local market price to a local extension service) for farmers to grow NERICA varieties. A follow-up survey was undertaken after the seed dissemination projects ended to examine the change in the cultivation of NERICA varieties. About half of the farmers had ceased cultivation of NERICA varieties in 2011. The reasons for abandonment were the combined effects of reduced seed demand and low yields, which were attributed to a lack of access to credit and training on NERICA cultivation practices. The majority of the farmers did not abandon rice cultivation, but grew other high-yielding varieties, including one aromatic variety for which there was market demand. We conclude that to avoid immediate reductions in the adoption of new varieties after projects are terminated and to enhance agricultural sustainability, the varieties should be introduced in conjunction with appropriate group training on their cultivation, and the project should target farmers who do not have off-farm businesses. Furthermore, access to credit should also be enhanced, and the marketability of the varieties should be assessed.  相似文献   

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This article employs a propensity score‐matching approach to examine the direct effects of adoption of Bacillus thuringiensis (Bt) cotton on yields, pesticide demand, household income and poverty, using cross‐sectional data from a survey of farmers in the Punjab province of Pakistan. Generally, the findings reveal that adoption of the new technology exerts a positive and significant impact on cotton yields, household income and poverty reduction, and a negative effect on the use of pesticides. The positive and significant impact of the technology on yields and household income is consistent with the potential role of new agricultural technology in directly reducing rural poverty through increased farm household income.  相似文献   

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We use a regulatory model with resistance evolution in two pests to insecticidal Bt cotton and pyrethroids (a conventional insecticide) to examine non-Bt cotton (refuge) planting requirements designed to manage Bt-resistance evolution in the midsouth. Our analysis suggests that reduced refuge requirements would enhance producer profitability, sprayed refugia are more cost effective than unsprayed refugia, and producers would receive slightly higher returns under dynamic relative to static refuge policies. Pyrethroid susceptibility in one of the pests was a renewable resource, and toxin-mixture effects associated with pyrethroid use in Bt cotton were important considerations for midsouth refuge policies.  相似文献   

17.
Risk associated with the adoption of new maize technology and the impact of mandatory cotton production on traditional farmers in the Kasai Oriental Region of Zaire are evaluated within a portfolio context using a quadratic programming model. Seasonal net returns for farm plans including four levels of maize technology in combination with staple food crops are evaluated, with and without mandatory cotton production. The results indicate that cropping systems that include new maize technology are risk-efficient relative to local maize varieties while mandatory cotton production is not risk-efficient at the prevalent price and yield levels in the farming system.  相似文献   

18.
We estimate the perceived costs of legal requirements (‘coexistence measures’) for growing genetically modified (GM) Bt maize in Germany using a choice experiment. The costs of the evaluated ex‐ante and ex‐post coexistence measures range from zero to more than €300 per measure and most are greater than the extra revenue the farmers in our survey expect from growing Bt maize or than estimates in the literature. The cost estimates for temporal separation, the highest in our evaluation, imply that the exclusion of this measure in Germany is justified. The costliest measures of the ones that are currently applied in Germany are joint and strict liability for all damages. Our results further show that neighbours do not cause a problem and opportunities for reducing costs through agreements with them exist. Finally, we find that farmers’ attitudes towards GM crops affect the probability of adoption of Bt maize. Our results imply that strict liability will deter the cultivation of Bt maize in Germany unless liability issues can be addressed through other means, for example, through neighbours agreements.  相似文献   

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Productivity assessment of damage control inputs (such as pesticides) is complicated because their effect depends on the exposure to damage agents (such as pests). We discuss some open specification and estimation issues. The contribution is threefold. First, we elaborate the separability conditions for the damage control function and production function. Second, we employ a two-stage semiparametric technique to combine attractive features of both nonparametric and parametric approaches. Third, we model the interaction between pest exposure and damage control inputs by using slope dummies. An application to productivity analysis of small scale Bt cotton production in China illustrates the approach.  相似文献   

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目的 由于生产要素的价格稳步攀升,新疆棉花生产成本过高,加上新疆棉花销售回归市场,价格不稳定,导致棉花生产风险增大,棉农种棉积极性降低。文章通过对新疆棉花成本收益及规模报酬变动趋势的研究,为棉农生产决策和政府政策提供参考。方法 在对新疆棉农问卷调查的基础上,研究棉花种植规模变动下生产要素的规模报酬。在二次函数的基础上寻找生产要素投入成本较低,收益最大的植棉规模,运用多元线性回归模型分析棉花生产要素投入对植棉成本的影响,以及不同植棉规模下生产要素对棉花产量增加的贡献程度。结果 新疆农户棉花生产的单位面积成本和收益随着户均种植规模的变化呈二次曲线变化;单位面积成本随着种植规模扩大,先下降,超过一定规模后上升,成本最低植棉规模为3.56hm2;单位面积收益随着种植规模扩大,先增加,超过一定规模后下降,收益最高的植棉规模为4.67~5.33hm2。研究发现,户均种植规模在2.5~4.5hm2时,土地费用、机械作业费、水电费、雇工费用投入对棉花产量的贡献较大,规模在7~10hm2时,化肥投入对棉花产量的贡献较大;农药、地膜、滴灌带等物质投入未体现规模趋势。结论 新疆农户棉花生产的成本和收益随着种植规模不同而变化的趋势符合规模经济原理,存在最优种植规模;在不同种植规模下,各种要素投入对新疆农户棉花产量的影响差异明显。因此,要引导棉农合理投入生产要素,降低成本,增加收益。  相似文献   

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