中国农业面源污染与经济发展关系的实证研究

把握现阶段我国经济发展过程中农业面源污染压力的演变规律,是制定农业可持续发展政策的基本依据。运用1998~2006年我国31个省（市、自治区）面板数据模型对经济发展与农业面源污染的环境库兹涅茨曲线(EKC)关系进行实证研究。选取各省化肥投入密度、农药投入密度、畜禽粪尿排泄物密度作为度量农业面污染源排放量的指标,选取各省人均国民生产总值作为经济发展衡量指标。研究结果表明,我国农业面源污染源排放量与经济增长总体上具有显著的倒“U”型曲线关系,三类污染源与人均GDP均处于曲线上升阶段,自发到达农业面源污染减排拐点还需较长时间。政府应强化农业环境政策的干预力度,加大对农业面源污染的治理力度。     

稻鱼共生系统生态服务功能价值比较——以浙江省青田县和贵州省从江县为例

石油农业导致生态系统退化与环境受损.人们在寻找新的农业途径时,将目光转向传统农业,开始对传统农耕模式的价值进行挖掘.稻鱼共生是最为典型的中国传统生态农业模式之一,因其历史悠久、景观独特和效益显著而被联合国粮农组织列为首批全球重要农业文化遗产保护试点之一.在数千年的农耕文化演变过程中,同宗的青田县和从江县的传统农业系统,由于受到不同的自然、经济和文化的影响,分别形成了以养鱼为主和以种稻为主的稻鱼共生系统.本文采用市场价值法、造林成本法、替代价格法、大气污染治理成本法和水库工程费用法等,分别对青田县和从江县传统农业区生态系统服务功能的经济进行评估.结果表明,以养鱼为主的青田县直接经济价值比以种稻为主的从江县平均每公顷高近1.70万元,但其闻接价值却比后者低,从江县稻鱼共生系统的气体调节和养分保持价值分别是青田县的1.35和1.59倍.最后,本文提出了提高农民收入的途径,以更好地保护这一具有全球重要意义的农业文化遗产.     

天王星对棉株叶组织超微结构的影响

施用不同浓度的农药于棉花生育期,通过电镜试验观察农药对棉株叶肉组织超微结构的影响。结果首次发现,棉株的叶肉细胞对病虫害危害和高浓度药剂处理的反应都很敏感,而低浓度药剂处理后的叶肉细胞趋于正常,表明了在本地区的农业环境条件下,农药可能会影响植物的超微结构并破坏其正常的生理代谢过程。图版２参１２     

湖北省农地利用碳排放时空特征与脱钩弹性研究

基于化肥、农药、农膜、农用柴油、翻耕、稻田6个主要方面的碳源,测算了湖北省1995~2009年及其地、市、州2008年的农地利用碳排放量。结果表明：（1）自1995年以来,湖北农地利用碳排量总体呈现“上升-下降-上升”的三阶段特征,其碳排放强度变化轨迹与此基本一致。（2）区域差异明显：农地碳排放总量,江汉平原、鄂东北地区高,鄂西、鄂东南地区较低;农地碳排放强度,总体呈现东高西低的特征,即鄂东>鄂中>鄂西。进一步运用Tapio脱钩模型对湖北省农地利用碳排放与农业经济发展间的脱钩关系进行了研究,发现以弱脱钩和强脱钩为主,可见近些年来农地利用碳减排取得了一定成效     

农业结构调整对全国粮食安全的影响分析--以粮食主产区为例

基于粮食主产区农业发展及其结构调整中面临的问题分析，指出近5年来导致我国粮食产量持续下降的主要原因在于农业结构调整。大规模的“压粮扩经”趋势若不能有效控制，必将对国家粮食安全带来冲击。对2005-2010年我国粮食需求及粮食主产区占全国粮食产量比重进行测算．提出不同粮食自给率下国家粮食安全对粮食主产区粮食生产的目标要求。粮食主产区具有满足国家粮食安全产量需要的生产潜力。     

云阳县生态危机的现状及其对策

为了改善生态环境，发展贫困地区经济，树立人与延期共同，协调发展观念，建立合理的农业结构和作物布局，详述了四川云阳县生态危机的现状和存在问题，提出了保护环境，发展立体农业的合理布局的建议。     

Testing a Simple Field Method for Assessing Nitrate Removal in Riparian Zones1

Abstract: Being able to identify riparian sites that function better for nitrate removal from groundwater is critical to using efficiently the riparian zones for water quality management. For this purpose, managers need a method that is quick, inexpensive, and accurate enough to enable effective management decisions. This study assesses the precision and accuracy of a simple method using three ground water wells and one measurement date for determining nitrate removal characteristics of riparian buffer zones. The method is a scaled‐down version of a complex field research method that consists of a large network of wells and piezometers monitored monthly for over two years. Results using the simplified method were compared to those from the reference research method on a date‐by‐date basis on eight sites covering a wide range of hydrogeomorphic settings. The accuracy of the three‐well, 1 day measurement method was relatively good for assessing nitrate concentration depletion across riparian zones, but poor for assessing the distance necessary to achieve a 90% nitrate removal and for estimating water and nitrate fluxes compared to the reference method. The simplified three‐well method provides relatively better estimates of water and nitrate fluxes on sites where ground‐water flow is parallel to the water table through homogeneous aquifer material, but such conditions may not be geographically widespread. Despite limited overall accuracy, some parameters that are estimated using the simplified method may be useful to water resource managers. Nitrate depletion information may be used to assess the adequacy of existing buffers to achieve nitrate concentration goals for runoff. Estimates of field nitrate runoff and buffer removal fluxes may be adequate for prioritizing management toward sites where riparian buffers are likely to have greater impact on stream water quality.     

典型矿业城市农田土壤重金属含量的空间结构特征——以辽宁省阜新市为例

运用地统计学方法对阜新市矿业密集区周围农田土壤重金属含量的空间结构特征进行了定量描述,并探讨了研究区域内重金属空间结构的主要影响因素.结果表明:研究区域农田土壤中As、Cd、Cu、Ni、Pb、Zn等6种重金属元素的实验变异函数理论模型拟合效果较好,决定系数均达到0.01显著性水平;各重金属变程较大,除As以外均出现明显的漂移;变异函数的块金效应明显,空间相关性属中等,显示小尺度上受人为干扰的影响较大;除Ni的空间结构表现为各向同性以外,其余5种重金属均表现出明显的方向性特点;除土壤母质因素外,研究区域内以矿业和城市活动为主的人为干扰是影响农田重金属空间结构的重要原因.     

黄土高原半干旱区雨水利用与可持续农业发展研究

黄土高原半干旱区是一个特定的生态类型和重要的农业区域 ,严重的水土流失和频繁的干旱是该区农业可持续发展的主要制约因素。本文在分析雨水利用可行性的基础上 ,提出了农业发展的有效模式———集水型生态农业 ,它不仅适应于当地的雨水等自然资源条件 ,更适应生产力发展水平 ,易于在农户水平上推广 ,并且具有显著的经济、生态和社会效益 ,是实现该区农业可持续发展的战略性举措 ,同时也为“退耕还林 (草 )”开发战略的实施提供了一个思路     

The transatlantic rift in genetically modified food policy

The regulatory structures underlying United States and European Union policies regarding genetically modified (GM) food and crops are fundamentally different. The US regulates GM foods and crops as end products, applying roughly the same regulatory framework that it does to non GM foods or crops. The EU, on the other hand, regulates products of agricultural biotechnology as the result of a specific production process. Accordingly, it has developed a network of rules that regulate GM foods and crops specifically. As a result, US regulation of GM foods and crops is relatively permissive, whereas EU regulation is relatively restrictive. Why are genetically modified food policies in the United States and the European Union so strikingly different? In the light of the recent World Trade Organization dispute on agricultural biotechnology, it may seem that economic interests are the driving force behind policies. While they are certainly part of the picture, the issue is far more complex. This paper argues that three different elements help explain differences between US and EU GM food policies. First, an investigation of US and European policies of the 1970s and 1980s on recombinant DNA research and of events leading up to early GM food and crop regulation allows a deeper understanding of current policy. Second, scrutinizing underlying values and norms can uncover the beliefs that condition current GM food and crop policy. Third, an analysis of involved actors’ views and levels of success in influencing policy is essential to understanding US and EU policies.