撬动罗非鱼国内销售市场的几点思考

罗非鱼是联合国粮农组织特别推荐养殖的优良鱼种,罗非鱼自身的特点决定了罗非鱼非常适合大规模人工养殖。我国已经成为最大的罗非鱼养殖国家。由于市场因素、国际金融危机等因素,使我国罗非鱼养殖产业出现了增产不增收的恶性循环现象。本文通过分析罗非鱼养殖和加工现状、罗非鱼系列产品开发、罗非鱼废弃物综合利用、政府制定优惠政策、培育规范的罗非鱼国内销售市场等,提出了切实可行的促进我国罗非鱼产业快速发展的途径,为我国罗非鱼产业的快速发展提供了参考。     

吉富罗非鱼与南美白对虾混养经济效益分析

为探索罗非鱼高产高效养殖新模式,研究开展了2000尾/亩、3600尾/亩和6000尾/亩不同密度罗非鱼与南美白对虾混养的养殖试验,并分析该养殖模式下的经济效益.结果显示：罗非鱼6000尾/亩高密度混养南美白对虾获得较大的池塘经济效益,为较理想的投资养殖方式;高密度罗非鱼与南美白对虾混养有利于降低罗非鱼养殖病害和养殖成本,提高池塘经济效益,促进罗非鱼产业健康可持续发展.     

吉富罗非鱼与锯缘青蟹混养经济效益分析

海南省罗非鱼产业已成为海南省渔业的支柱产业之一,然而,近年来病害的频发、国际市场的不稳定性、饲料、人工成本的不断增加,直接制约了罗非鱼产业的可持续发展。多品种混养的池塘养殖模式悄然兴起,一方面充分利用池塘水域环境,通过生物与生物之间的关系,调节了水质,提高了养殖品种的成活率;另一方面,通过混养其他经济品种,提高池塘单位面积的经济收益。论文以吉富罗非鱼与锯缘青蟹混养为例,探讨了该养殖模式下养殖成本、养殖经济效益与单养模式的区别。结果表明：罗非鱼与锯缘青蟹混养既能减少养殖病害,有良好的生态效益,又能有效提高罗非鱼单位面积产量,增加养殖总体的经济效益。     

巴西罗非鱼养殖业潜力巨大

正荷兰合作银行发布的最新调查结果显示,巴西罗非鱼养殖业发展潜力巨大。每年将以10%的速度发展,预计到2020年养殖罗非鱼的产量可达到50万吨。全球最大的罗非鱼养殖公司Regal Springs进入巴西,大力推动巴西罗非鱼业的发展。去年该公司与Axial集团强强联合,在巴西建立了一家大型罗非鱼养殖公司,目标是2020年罗非鱼产量达到10万吨。巴西的气候和自然条件非     

罗非鱼链球菌病的综合防治技术

<正>罗非鱼又名非洲鲫鱼，属于热带鱼类，该鱼具有生长速度快、产量高、食性杂、无肌间刺、抗病力强、易于饲养等优点，是我国南方地区的主要养殖品种，但随着养殖环境的恶化和养殖密度的不断增大，罗非鱼链球菌病的发病率不断增加，成为罗非鱼养殖的主要疾病，给罗非鱼产业带来了严重的经济损失。现从养殖实践出发，就如何综合防治罗非鱼链球菌病提供参考经验。     

如何从技术角度提升罗非鱼养殖效益

<正>罗非鱼是国家农业部建议大力推广的名优养殖品种,罗非鱼养殖逐渐成为很多地方农民增收致富的新途径。但是,在近年许多养殖者发现罗非鱼养殖出现投入上升而产效不高的现象。现结合实际,对当前罗非鱼养殖产效不高的原因及对策进行分析和疏理,以供参考。一、罗非鱼养殖产效不高的原因分析1.水面选择不正确。许多养殖者认为     

微利时期养殖罗非鱼?增收措施

正近年来,由于原材料、饲料等价格的大幅提高,导致罗非鱼养殖成本上升,同时,受罗非鱼国际市场低迷影响,罗非鱼养殖经营进入了微利或亏本经营的困境。在这样一个市场低迷、效益惨淡的困难时期,有的养殖户往往不讲求养殖规范,一味片面追求产量,在养殖水体乱投饲料及肥料等,不但使养殖成本日益上升,而且使水质不断恶化,影响罗非鱼的生长乃至     

无公害网箱养殖奥尼罗非鱼技术

<正>罗非鱼目前已是国际上养殖最广泛的鱼种之一。我国罗非鱼产量虽然逐年增加,但养殖环境污染的加剧、渔用药物的滥用和饲料添加剂的不合理添加等因素制约我国罗非鱼出口量。为此,我们对奥尼罗非鱼水库网箱养殖采用无公害方式进行。     

广西摸索出罗非鱼对虾的“绿色药方”

<正>给罗非鱼打预防针,"吃药"防病;给金枪鱼做"鱼医"看病,给对虾"治病"。近年来,国家现代农业产业技术体系广西罗非鱼、对虾创新团队在鱼虾养殖过程中,摸索出了一套"绿色药方"。口服疫苗罗非鱼防病有一套近年来,广西罗非鱼养殖面积、养殖产量居全国第3位,已成为广西出口创汇的最大宗农产品。在当前水产养殖中,罗非鱼死亡问题尤显突出,链球菌成为了罗非鱼的头号杀手,是当前水产疾病的头号"疑难杂症"。     

罗非鱼咸淡水池塘养殖技术

罗非鱼为广盐性鱼类．不仅能在淡水中养殖，也能在海水和成淡水中养殖．而且海水和成淡水养殖的罗非鱼的肉质优于淡水养殖的罗非鱼，深受养殖户和广大消费者的欢迎。我县从20世纪80年代中期开始发展罗非鱼的咸淡水养殖，在近20年的养殖实践中．逐渐摸     

Application of an ecosystem function framework to perceptions of community woodlands

Owners, local residents, government, and conservation organisations can express divergent preferences in the development and management of local woodlands. The perceptions of these four groups were examined, in the context of three community woodlands in Eastern England, using an ecosystem function framework. In a pilot study, residents were able to allocate a relative importance to woodland ecosystem services which were then related to “regulation”, “habitat”, and “production” or “information” functions. However residents also placed importance on negative services or “dis-services” associated with the woodland ecosystem. Therefore a fifth category of “dis-services” was included in the main survey which included 84 local residents, three woodland owners, three government institutions, and six representatives from conservation groups. Each of the four groups placed greatest importance on services associated with habitat (16–39% of the total importance) and information (30–50%) functions suggesting, in this example, mutual interest in the use of woodlands as a habitat or recreational resource. By contrast a potential area of difference was the particularly high importance placed by one owner on dis-services such as fly tipping. In addition the woodland owners placed higher importance (10–20%), than local residents and conservation groups (7–9%), on the productive services of the wood. This suggests a need for communication when production-related operations affect recreation. The ecosystem function framework appears to be a useful approach for highlighting potential tensions and areas of mutual interest in the management of semi-natural ecosystems.     

The Effect of the Structural Adjustment Program on the Output,Prices and Exports of Major Agricultural Export Crops in Nigeria

The primary objective of this paper is to examine changes in the level of output, prices and exports of major export crops resulting from the Structural Adjustment Program (SAP) in Nigeria. THere two main sources of data: the Central Bank of Nigeria (CBN) through its annual reports, Economic and Financial Review, and the Nigerian Federal Office of Statistics (FOS) through its Trade Summaries. Although the SAP led to appreciable increases in output and producer prices, its effects on exports were insignificant. The implications of these for the implementation of the program are explored.     

土地学科的建设和发展——"土地学科发展规划研讨会"综述

中国土地科学学科发展已取得很大成就,表现为专业教育和人才培养成绩突出、初步形成学科体系、取得大批研究成果.而存在的问题主要是基础理论研究欠缺、独特的土地科学研究方法体系尚未形成、研究角度单一、学术交流质量不高和学科带头人的影响力不足.土地科学学科发展目前面临着巨大的机遇和挑战,应明确土地科学学科发展的基本思路、发展目标及2010-2020年的主要建设任务和保障措施.     

An evaluation framework for earthquake-responsive land administration

In recent years earthquakes and their secondary hazards have claimed the largest number of lives of all large natural disasters. Some of the world’s most earthquake-prone zones are also areas of high population density. The impact is magnified by vulnerability factors including non-enforcement of building codes, knowledge gaps, urban poverty and poor governance capacity to manage and reduce earthquake risks. Poor security of land tenure and property rights increases the vulnerability of people and affects their ability to respond to natural disasters.Earthquake recovery and reconstruction provides very significant challenges for land agencies, with these challenges differing from one country to the next due to differences in the local context. Drawing on contrasting case studies in Haiti, Nepal and New Zealand this paper identifies the common post-earthquake land administration functions and challenges that may apply to many contexts. These lessons provide land agencies and other key stakeholders with a summary of the challenges an earthquake poses for land administration at different post-disaster stages. We also discuss the policy and regulatory, institutional, operational and preparedness lessons for land administration. From these lessons we propose a framework for evaluating the earthquake-responsiveness of a land administration system. This framework can be used by a land agency in an earthquake prone region, or where an earthquake has recently occurred, to assess what challenges to land administration might occur in the event of an earthquake, and the preparedness of their land administration system.     

Evaluating Alternative Policy Responses to Higher World Food Prices: The Case of Increasing Rice Prices in Madagascar

Higher world food prices have led many developing countries to adopt policies to mitigate the impact on low-income households. This article sets out a partial equilibrium framework to evaluate the efficiency, distributional, and revenue implications of alternative policy responses. The model is applied to evaluate tariff reductions and targeted transfers in Madagascar. Although lowering tariffs generates substantial efficiency gains, these accrue mainly to the top half of the welfare distribution, and poor net sellers are actually worse off. Developing a system of targeted direct transfers to poor households is likely to be a substantially more cost-effective approach to poverty alleviation.     

Agrarian Poverty,Nutrition and Economic Class – A Study of Gujarat,India

This paper analyses poverty and calorific undernourishment in the Indian state of Gujarat, where high and market‐led industrial growth has resulted in rapid economic improvement. The study is carried out through a combination of secondary and survey‐based data. We conclude that the neoliberal agenda of uncontrolled, outward‐looking growth has not resulted in significant reduction of poverty or malnourishment in rural areas. Furthermore, while land ownership is officially used as a proxy for wealth distribution, class position appears a better predictor of poverty status in the rural areas than landownership per se. At the policy level, there is a need to revive the agrarian economy and create new non‐agricultural assets, and the primary focus in the state must shift to the distribution of created assets rather than a single‐minded focus on growth.     

Revealing different understandings of soil held by scientists and farmers in the context of soil protection and management

This paper aims to analyse and draw together results from similar studies in England, Switzerland and France which investigated farmers’ understanding of soil and compared it with that of scientists, researchers and advisors (collectively called scientists in this analysis). A range of methods were used across the three studies and different theoretical approaches, looking at forms of knowledge, local practice of knowledge production and conceptions of reality, were employed to explain the results. Despite the different contexts, methodologies and theoretical approaches in the three studies, the results reveal similar patterns of difference in farmer and scientist understanding of soil. In the English study, farmers demonstrate a ‘know-how’ form or intuitive working knowledge of soil while advisors rely on scientifically established forms of ‘know-why’ and seek to understand and explain soil processes. Similarly in the Swiss study farmers’ and scientists’ differing perceptions are directed and shaped by their respective aims, methods and context of work. In the French study, farmers and researchers are shown to have different conceptions of soil, they attribute different meaning to the same activities, and use different words and language to describe the same features. In all three studies understanding is shown to be cultural and contextual, as such an integrative theoretical framework is proposed.     

Transaction Cost Thresholds in International Rice Markets

Recent episodes of high and volatile prices for grains such as rice have raised concerns about their implications for hunger and poverty. We model price relationships between international rice prices and 221 domestic prices in 47 developing countries that import rice. We use a threshold vector error correction model that accounts for transaction costs of trade in spatial price transmission, and an improved regularised Bayesian threshold estimator for threshold models. Our results show that threshold values are higher after 2008 than before, which suggests that transaction costs in international rice trade have increased in recent years. Threshold values are highest for Latin American countries followed by African and Asian countries, and higher for retail than for wholesale prices. Since 2008, price transmission is slower in countries that responded to high and volatile prices with domestic market‐based interventions such as price controls and faster in countries that responded by lowering tariffs and by implementing production support measures.     

森林生物多样性评价模型的改进

针对2002年的评价模型中的不足,提出了新的改进后的森林生物多样性变化的评价模型,并在我国第六次森林资源清查(1999～2003)资料的基础上,对1973～2003年我国森林生物多样性的变化进行了补充评价。评价结果表明:我国森林生物多样性的压力越来越大,压力指数由1973年的100,上升到2003年的199.10,上升了1.99倍;森林物种多样性总体的下降趋势已有一定幅度的改变,森林物种多样性指数增加了31.12%。森林生态系统多样性和森林生物多样性先逐渐上升,尔后又下降,第六次森林资源清查时又有所恢复,并分别上升了4.67个百分点和17.90个百分点。     

Does sustainable agricultural growth require a system of innovation? Evidence from Ghana and Burkina Faso

This paper tests the ‘systems of innovation’ hypothesis for a selection of crops in Ghana and Burkina Faso that have shown significant growth in production over an approximately 20-year period. The question is whether such growth can only occur if supported by a system of innovation. Using two indicators (a common understanding on objectives and priorities, and a high level of interactivity), we find little evidence for the existence of anything that might be considered a high functioning system of innovation.