解决青虾养殖过程中小规格虾过多的途径与方法

<正> 青虾现已成为我国重要的淡水养殖对象,优化养殖结构的主要品种,近几年来出现了快速发展的势头。但由于当年放养的虾苗秋季需要繁殖,因而在青虾养殖过程中,存在大小虾同池,小规格虾比例过大的矛盾,严重影响了青虾养殖的规格质量和经济效益,成为青虾养殖发展上的一大制约因素,也是广大养殖户最感头痛的技术难题。如何解决这一技术难题,笔者根据多年的经     

中国林蛙人工养殖现状及发展对策

介绍了中国林蛙的分布、资源现状和养殖现状：分析了目前的各种养殖模式的优缺点、妨碍林蛙养殖业发展的若干问题以及应采取的对策。     

中国林蛙的人工养殖

为了更好地培养和开发中国林蛙资源,变资源优势为商品优势,根据生态学地空差和生物间同生互利的原则,制造生态和食物的能量转换,创造生态集纺化的人工养殖环境和条件,敢中国林蛙的饲料、喂养、越冬、防止、逃逸、防治天敌、快速育蛙等技术措施,使中国林蛙人工养殖获得成功。     

我国庭院水产养殖的现状及发展趋势

庭院水产养殖是指将庭院范围内的空地、空房、小水坑等加以改造，进行水产养殖的一种生产方式。它具有占地少、投资小、管理方便等特点，并能让人们     

中国林蛙养殖利用的若干技术问题

中国林蛙（Ｒａｎａｃｈｅｎｓｉｎｅｎｓｉｓ）的输卵管俗称蛙油．是医药、轻工、食品等行业的重要原料．其实用价值极高．利用自然条件放养中国林蛙．首先要从地形、植被、河流等方面．选好生态条件．然后再根据它的繁殖和生长发育特性．修筑孵化池、变态池和越冬池．进行人工养殖蝌蚪和幼蛙．为了增加产量．获得最佳的养殖效果．挑选了３－４年龄的雌雄比例为１：－１．１￣１：１．２的优良品种蛙作种蛙．冬季进行水贮或温贮．精心管理。回扑中国林蛙可依据其生活习性、在秋、冬季节采用设塑料布障子、瓮、磁电机等多种方法。剥取蛙油以干剥的效果最佳．质量最好。     

克氏原螯虾养殖存在的问题及分析

<正> 克氏原螯虾又名淡水龙虾,由于近年来的开发利用,淡水龙虾市场需求加大,价格逐步上涨,淡水龙虾的人工养殖面积也开始扩大,然而到目前为止,主养淡水龙虾成功者甚少,试行鱼虾混养者却有部分获得成功,但仍与预期目标相差较远,经调查     

高安市濠溪养殖公司发展养猪业的调查

高安市濠溪养殖公司发展养猪业的调查王少东自１９９５年开春以来，全国各地生猪生产普遍随着饲料价格不断上涨和生猪销价持续偏低的双重压力，生猪养殖业进入了一个全面性的低速徘徊状态，许多养猪企业“因消化能力弱”而出现亏损，有的甚至倒闭。而兴办至今仅３年多的高...     

唇鱼骨的养殖技术及发展前景

<正>辽宁省有着很多重要的经济鱼类,但近年来由于其价格昂贵,酷捕、滥捕现象严重,造成资源急剧下降。因此,我院近几年来开展了名贵土著野生经济鱼类人工驯化、繁殖及养殖技术研究。这是我省乃至全国淡水渔业发展的一个趋势,如黄颡鱼、鲶的驯化养殖成功大大促进了淡水渔业的     

发展鲫鱼养殖具有广阔前景

鲫鱼是我国重要食用经济鱼类之一，经过历年择优选育，各地推行养殖的品种除本地土鲫外，主要有丰产鲫、彭泽鲫、工程鲫、高背鲫、异育银鲫、湘云鲫等新品种，这些品种不仅适应性强，而且是杂食性鱼类，在天然水域中主要摄食动植物与有机碎屑等，在人工养殖条件下也摄食投喂的精料。     

我国社区支持农业(CSA)信任机制构建研究

从国际社区支持农业(CSA)的发展比较来看,目前我国CSA发展缺乏有效的信任机制。根据心理学家John Rempel提出的伙伴间信任关系理论并结合我国CSA实践,本文构建了CSA信任机制三要素分析框架——可预测的行为、可依赖的能力、可持续的信念,开展了CSA信息不对称动态博弈分析。研究发现:构建CSA信任机制的关键是确定预付款比例,在CSA发展的初期预付款比例要高,随着CSA附加价值占比增加,降低预付款比例并不影响双方信任关系的增进,此时应当扩大CSA的会员规模。在此基础上,本文提出推进我国CSA信任机制建设的举措,以预付款制度建设为主线,提高CSA生产者行为的可预测性,增强CSA可依赖的基础条件及能力,以及培育CSA可持续发展的信念。     

中国农业支持水平衡量与评价

本文运用OECD的方法对我国1994—2003年的农业支持水平进行了实证分析。结果表明,我国农业支持水平总体呈上升趋势。20世纪90年代后期农业基础设施投资的大量增加、粮食保护价收购政策的实施使得农业生产者支持水平从2000年起由负向正转变。但是与世界发达国家相比,我国的农业支持水平依然很低,政府应该进一步加强对农业的支持和保护力度。     

唐代寺院的水碾硙经营

唐代佛教寺院经济发展到了兴盛阶段，其经济活动和整个社会生活有着密切的联系。寺院大规模的水碾硙经营活动，对于国家经济和管理制度都产生了重要影响。唐王朝水权管理制度的变迁，在国家制度建设方面有着重要意义，但在实际执行过程中其绩效有限。从佛教寺院水碾硙经营的角度进行考察，表明唐代寺院经济与当时国家制度有着密切的互动关系，而且其影响已逐步深入到社会生活的各个层面。     

Economic impacts of integrated pest management (IPM) farmer field schools (FFS): evidence from onion farmers in the Philippines

This article comprehensively examines the impact of integrated pest management‐farmer field school (IPM‐FFS) on yield, insecticide expenditures, labor expenditures, herbicide expenditures, fertilizer expenditures, and profit, based on data from onion producers in the Philippines. Propensity score matching (PSM) and regression‐based approaches that account for potential bias due to selection problems from observable variables are used to achieve the objective of the study. Sensitivity of our IPM‐FFS impact results to potential bias due to “selection on unobservables” was also assessed. We find that farmers who participate in the IPM‐FFS training program have statistically lower insecticide expenditures than the non‐IPM‐FFS farmers. But we do not find any evidence that the IPM‐FFS training program significantly affects yield and the other inputs. There is some evidence indicating that IPM‐FFS farmers may have statistically higher profit levels than non‐IPM‐FFS producers, but these results are sensitive to and may still be invalidated by bias due to unobservable variables. Since IPM‐FFS seem to only significantly reduce insecticide use, policymakers and extension educators may need to adjust the IPM‐FFS curriculum to further emphasize (or include) other agronomic practices that also optimize the use of other inputs like labor, fertilizer, and herbicides. The more efficient use of all inputs would likely reduce total expenditures and eventually translate to higher incomes.     

黑龙江省野生北五味子钾素分布及动态趋势

通过对黑龙江省三大产区野生北五味子采样分析,植株钾素含量,果实>花>叶>根和茎;根茎等运输器官在生长早期到生长中期钾素含量有所上升,到终花期又有所下降;叶、花、果实在整个生长期内钾素呈逐步积累上升趋势。     

国外速生丰产林发展对中国的启示

通过分析国外速生丰产林发展较好国家的法律政策、技术支持、政府扶持等,从中获得对中国速生丰产林发展的启示。     

Insights into a black box! Comparison of organizational modes and their monetary implications for the producers of short rotation coppice (SRC) in Brandenburg/Germany

A substantial change in energy policy in Germany towards the substitution of fossil, nonrenewable energy resources is part of a current political and social process. This change has been accelerated by the government’s decision in summer 2011 to phase out nuclear energy, a direct result of the nuclear disaster in Fukushima, Japan. As part of this development, new business activities and modes of organization for the provisioning of energy from alternative sources have emerged; one such activity is short rotation coppice (SRC) cultivation on agricultural land. In this paper, we compare the two prevailing organizational modes for SRC: independent production and contract farming. We use a mixed-methods approach to examine these modes from the producers’ point of view in Brandenburg/Germany. First, we give reasons for the producer’s choice between these two modes of organization based on the interviewee’s qualitative assessment of how these modes cope with perceived SRC-related challenges e.g. uncertainties. As economic uncertainty plays a major role in both refusal to adopt SRC and the choice of the mode of organization for SRC production, we secondly model the unknown economic outcome of the independent mode. We thereby give insights into the “black box”. This consists on the one hand of lacking economic figures for an economic comparison of both modes, and on the other hand of the producer’s decision-making process between both modes. For the latter, we use the theoretical approach of transaction costs to display ostensible non-monetary decision factors. Using a known monetary reference for the contract farming mode, we are able firstly to support a comparison of economic factors and secondly to identify and interpret the critical variables whose manifestations and/or changes are decisive for the economic outcome. The modelling results show that neither of the two modes performs better per se. This finding suggests that the weight ascribed to the transaction costs of SRC in each individual producer’s decision-making process is decisive for the producer’s choice of mode.     

枸杞种植户参与紧密纵向协作的意愿及影响因素分析

运用二元Logistic回归模型分析了枸杞种植户参与假定的纵向协作形式的意愿及相关影响因素。研究表明:枸杞收入占家庭总收入比例较高和生产规模大的枸杞种植户倾向于参加紧密纵向协作形式,枸杞种植户乐意参与紧密的纵向协作,与紧密纵向协作链接市场及技术、资金支持等方面的优势也是分不开的。     

内蒙古可持续退耕还林(草)新模式的探究

首先了解和掌握了内蒙古各地区在实施退耕还林(草)工程中普遍存在的资金、技术和政策问题,然后根据内蒙古东、中、西部地区生态地理环境逐渐恶化的特点,对内蒙古全区的退耕还林(草)问题进行分区分析,在东、中、西部分别选取呼伦贝尔盟、赤峰市、乌兰察布盟,借鉴三个盟(市)的经验,分别探讨进行农田防护林建设、股份合作造林、与农业产业化结合退耕三种适合东、中、西部地区的退耕还林(草)模式,值得内蒙古其他盟(市)推广和借鉴。     

A critical stakeholder analysis of the Trans-ASEAN Gas Pipeline (TAGP) Network

This article uses research interviews, field research, and critical stakeholder analysis to identify the relevant actors and institutions involved in the Trans-ASEAN Gas Pipeline (TAGP) Network, a proposed multibillion dollar energy project in Southeast Asia. Based on more than 100 interviews at government institutions, multilateral development banks, universities, consulting firms, energy companies, and nongovernmental organizations, along with field research in Indonesia, Japan, Malaysia, Philippines, Singapore, and Thailand, the article traces the interests, resources, and agendas involved with TAGP stakeholders. The article finds points of conflict between stakeholders as well as motivations for convergence and cooperation. The article provides insight into whether private interests will trump the public good potential of the TAGP, and also critically questions the efficacy of multilateral coordination on energy issues within Southeast Asia.