小农发展气候智慧型农业的效率与成本改进:倡导农地流转还是发展社会服务?

气候智慧型农业是联合国粮农组织所提出的积极响应气候变化、有效保障作物生产安全的新型农业发展模式。碳减排是发展气候智慧型农业的核心要义,而中国大量且长期存在的小农是发展气候智慧型农业不可背离的重要主体。基于湖北省水稻主产区气候智慧型农业发展的调研,继而利用方向性距离函数对小农发展气候智慧型农业,即低碳生产效率与碳边际减排成本进行测算,并进一步考察小农通过土地流转或农业社会化服务衔接现代农业,对低碳生产效率和碳边际减排成本的影响。结果表明:(1)基于小农发展气候智慧型农业仍处于"低效率—高成本"阶段,水稻低碳生产效率仍存在平均56%的提升空间;碳边际减排成本均值为34.13元/kgCE;(2)土地转入虽未能提升水稻低碳生产效率,但却具有碳边际减排成本优势;(3)生产雇工和农机服务对水稻低碳生产效率和碳边际减排成本均具有显著的正向影响,可见通过农业社会化服务实现低碳生产效率的提升仍面临分工与交易费用的两难之困。基于上述结论,提出促进小农发展气候智慧型农业,实现低碳生产相关政策启示。     

锦标机制理论下企业低碳经济发展激励机制研究

按照企业发展与环境相容的原则,低碳经济是应对全球变暖的最佳经济模式,低碳经济以低能耗、低排放、低污染为基本特征,以应对碳基能源对于气候变暖影响为基本要求,以实现经济社会的可持续发展为基本目的.鉴于当前文献关于企业发展低碳经济的激励机制研究还略显不足,文章借鉴激励理论中的委托代理理论,根据Malcomson模型的研究方法,构建了包括1阶段合约和2阶段合约的企业发展低碳经济的激励机制框架,设立基于相对业绩的"锦标机制"模型并对模型进行系统分析,推导出政府在制定企业发展低碳经济激励政策时的注意事项,即中央政府要加大财政转移支付力度,支持地方发展低碳经济;地方政府要设立专门的低碳经济发展激励基金,并纳入财政预算管理;地方政府在激励企业发展低碳经济时,要有层次、有针对的对企业给予政策支持或财政补贴,形成阶梯式的支持结构,使有限财政资金得到合理配置;地方政府应该以区域内企业实施低碳经济活动的努力水平为评判标准对企业进行激励.     

中国省域低碳农业绩效评估及边际减排成本分析

本文在构建含有期望产出与非期望产出农业经济核算框架的基础上,利用方向距离函数估算了中国31个省(市、区)的低碳农业绩效水平,并引入碳排放影子价格对各省区的农业边际减排成本进行了分析。结果显示:1北京、天津、上海三地处于低碳农业绩效1区,距离函数值均为0,其余省区低碳农业绩效水平相对较低;2海南、福建、山东、辽宁、广东、北京、天津等省区三年平均农业碳排放影子价格处于前列,减排成本较高;而西藏、青海两地农业碳排放影子价格最低,农业减排成本较低;3全国农业碳排放平均影子价格呈逐年增大趋势,且农业碳排放影子价格与农业碳排放强度密切相关;4基于距离函数值、碳排放影子价格的数值差异,将中国31个省级行政区域划分为四类:内蒙古等4省1市1区属于"高绩效低成本"型地区;北京等8省2市属于"高绩效高成本"型地区;江西等5省3区属于"低绩效低成本"型地区;山西等5省1市1区属于"低绩效高成本"型地区。     

新型农业经营主体能促进生态农业技术推广吗——以稻虾共养技术为例

新型农业经营主体能提高农业专业化、规模化水平,是实现农业绿色发展的重要途径.为进一步探究其对推广生态农业技术的影响,基于湖北、湖南、安徽共930份微观调查数据,运用双变量Probit模型和解释结构模型,实证分析了新型农业经营主体对推广生态农业技术的影响及其层次关系.结果表明:(1)新型农业经营主体对稻虾共养技术的采纳意愿和采纳行为均有显著正向影响;(2)农业合作社、种养大户或家庭农场对稻虾共养技术的采纳意愿和采纳行为均不显著,但农业企业对稻虾共养技术的采纳意愿和采纳行为均有显著正向影响;(3)影响层次方面,技术含量、种养历史和土壤质量是影响经营主体采纳意愿和采纳行为的直接驱动因素,而年龄和地形条件是影响经营主体采纳意愿和采纳行为的深层次因素.     

三类农业产业化模式经营主体间博弈分析及最优选择

农业产业化是提高农业生产效率的有效手段,农业产业化模式的优化选择是实现农业经营方式现代化的必由之路。从企业和农户间利益联结紧密程度看,中国农业产业化发展过程中依次出现了"龙头企业+农户"、"龙头企业+农户合作社+农户"、"企业+股份合作社+农户"三类主要模式。本文以图示模型为工具,将三类模式进行了分类归纳描述,并论述了"农户合作社"和"股份合作社"的区别与联系。基于农业规模经营的视角,通过对三类农业产业化模式经营主体间在交易环节和加工环节进行博弈分析,最终得出农户通过股份合作经营可以获得农产品经营的规模效益,实现交易和加工的剩余价值最大化。剩余规模越大,合作主体间的利益越大,双方的合作也越稳定。"龙头企业+农户"是市场机制下靠购销关系将企业和农户联结的农业产业化运作模式,具有灵活多变的特点,但主体间权责关系不明,难以稳定运行;"龙头企业+农户合作社+农户"模式下引入中介合作组织后,经营主体间合作边界条件并没有降低,扩大了经营的规模效应,经营主体间合作可能性增加;"企业+股份合作社+农户"模式采用了现代企业制度的组织方式,经营主体间合作边界条件显著降低,使农户收益由农产品收购深入到农产品深加工领域,扩大了农户利益空间,实现了经营模式的现代化,此模式成为最为稳定的农业产业化模式。三类农业产业化模式的稳定性依次增加,经营主体的收益依次更高,股份合作社模式是农业产业化最优模式。最后,从上述结论出发,提出了我国推进农业产业化的相关建议。     

论生态视角下的低碳农业发展

农业低碳化发展是低碳经济社会发展的重要组成部分。低碳农业是现代农业发展模式的创新,其根本任务是节能降耗,减少农业和农村生产生活的碳排放,以维护农业生态系统碳循环的速率平衡和生物多样性。本文在低碳发展时代背景下,采用多学科交叉及其理论分析方法,从生态学的视角对低碳农业发展的相关问题进行探讨。低碳农业应是一种有利于环境保护、有利于农产品数量和质量安全、有利于可持续发展的现在农业发展形态。低碳农业发展应树立持续性、协调性、公平性目标;坚持可持续性原则、公平性原则、有序利用原则以及节约资源、保护环境原则;要遵循生态学规律,建立健全低碳农业发展的生态保护机制、生态修复机制与生态补偿机制;从树立农业生态文明理念、转变农业发展方式、推广农业节能减排技术、减少农业面源污染、提高农村能源利用效率等方面,完善政府在低碳农业发展中的生态责任,以促进农村环境的不断改善和现代农业的健康运行与可持续发展。     

基于委托代理模型的企业环境行为研究

本文首先分析了影响企业循环经济行为的因素,归纳为政府管制、社会需求、市场需求和自身需求。其次,构建了委托代理模型,政府、社会和市场通过一定的激动和监督手段来规范企业的环境行为,企业通过努力来获得经济效益和规避环境风险,通过设计双方在信息不对称情况下的委托—代理模型,分析政府和企业如何订立优化合约和政府如何选择有效可行的监督力度。结果表明,信息不对称条件下,企业推行绿色管理模式的努力水平,取决于这种努力能够带来的经济效益、环境效益与努力成本之间的比值。最后,给出了如何发展绿色经济的建议。     

农户参与农业生态转型:预期效益还是政策激励?

农户作为农业生产经营的基本主体,农户参与农业生态转型行为是我国农业转型的关键。预期效益和政策激励是影响农户参与农业生态转型的两个重要方面,两者作用如何是值得探讨的重要命题。本文基于山东省两县级市507份设施蔬菜农户调查数据,分析农户参与农业生态转型的影响因素,并运用ISM模型判定各影响因素的内在关联关系和层次结构。研究发现:第一,预期效益中的环保型技术成本预期、废弃物回收利用成本预期对农户农业生态转型参与行为具有阻碍作用,预期效益中的收入预期对农户农业生态转型参与意愿具有促进作用。第二,政策激励中的政府监管和政策补贴对农户农业生态转型参与行为具有明显的靶向指导作用。第三,环保型技术成本预期、废弃物回收利用成本预期等预期效益因素是表层直接因素;政府监管、政策补贴等政策激励因素是深层根源因素。因此,要推进优质优价农产品市场机制形成,提供农业生态转型示范模式。推动设施蔬菜生产的绿色化、优质化、品牌化建设,加强按照环境友好型方式生产出来的绿色蔬菜的辨识度。重视绿色蔬菜示范基地建设,探索可复制可推广的农业生态转型模式,增强农户进一步参与农业生态转型信心。同时,政策约束与政策激励结合,落实农业生态转型政策激励。运用大数据科学制定农业政策,对污染环境、影响农产品质量安全的农业生产方式要严格禁止,并采取经济惩罚措施。对环境友好型生态农业生产方式要加以鼓励引导,对生态循环农业生产给予适当补贴,同时强化政策执行和舆论监督。     

日本第四次修订《食品、农业和农村基本法》及启示

日本政府2015年推出了《食品、农业和农村基本法》的第四次修订,以保证粮食供应和食品安全;推动集约化农业经营,保障农业收入稳定;推动农产品出口和农业技术创新;改善补贴政策,稳定农村人口作为下一阶段日本兴农政策的核心内容。我国农业发展面临许多与日本相似的问题,如农业经营规模小、效率低,务农收入低、人口显著减少等。在我国城镇化和农村劳动力老年化加速的背景下,分析和借鉴日本最新的兴农政策,提出对我国农业政策的若干启示:1以我国近期最新颁布的《食品安全法》和农药残留、化肥实施等国家标准的落实、健全为法制保障基础,推进农业标准化生产和规范化经营管理、建立食品生产全程可追溯机制、加强省县乡三级农产品和食品监测检验能力建设,以尽快提升我国食品安全水平;以培育需求和引导兴趣、技术支持、市场协助建设为手段,激励农户和消费者自主投入生态农业发展。2重点完善国家层面的发展战略统筹和政治、经贸、投资谈判支持,依靠政府的强力支持推动已起步的"一带一路"食品与农业投资发展势头,以壮大我国农产食品出口和农业海外发展。3近期以加强土地流转监管法律政策和财政金融配套扶持政策的建设为主,使支持力度集中于土地实际经营者,以有效提升新型规模化农业经营主体的数量和质量。4将农业补贴由集中于农业生产补贴向兼顾农户收入保障和生态保护、农业发展转移,将农户收入保障形式由财政补贴向保险保障转变,以求农业补贴和保险更高效、长久地兼顾农户收入保障和支持引领农业发展。     

中国发展碳汇农业的主要路径与政策建议

目前国内研究低碳经济,对农业领域的碳源、碳汇功能等相对关注较少。事实上,农业既是全球重要的温室气体排放源,又是一个巨大的碳汇系统。当前我国是世界上农业温室气体的排放大国,农业发展过度依赖化肥、农药等高碳型生产资料,耕地土壤有机碳含量明显降低。因此,发展碳汇农业刻不容缓。研究表明,碳汇农业发展路径主要包括:大力发展资源节约型循环农业,减少对高碳型生产资料的依赖;积极推广有机农业,增强农业碳汇功能;发展休闲观光农业,减少农作物的碳排放量;改变传统的耕作方法,提高土壤的固碳水平。针对碳汇农业属于新兴产业,需要政府进行相关的制度创新与政策引导支持,本文重点提出六条政策建议:建立健全资源、环境有偿使用制度,开征环境税,构建发展碳汇农业的长效机制;建立有利于发展碳汇农业的保障体系与激励机制;设立"农业碳基金",推进碳排放权交易;鼓励各类资本下乡,推动碳汇农业的发展;改变传统农业的组织形态,大力推进各种形式的农业专业合作;征收进口农产品"碳关税",补贴国内碳汇农产品。     

Distant agricultural landscapes

This paper examines the relationship between the development of the dominant industrial food system and its associated global economic drivers and the environmental sustainability of agricultural landscapes. It makes the case that the growth of the global industrial food system has encouraged increasingly complex forms of “distance” that separate food both geographically and mentally from the landscapes on which it was produced. This separation between food and its originating landscape poses challenges for the ability of more localized agricultural sustainability initiatives to address some of the broader problems in the global food system. In particular, distance enables certain powerful actors to externalize ecological and social costs, which in turn makes it difficult to link specific global actors to particular biophysical and social impacts felt on local agricultural landscapes. Feedback mechanisms that normally would provide pressure for improved agricultural sustainability are weak because there is a lack of clarity regarding responsibility for outcomes. The paper provides a brief illustration of these dynamics with a closer look at increased financialization in the food system. It shows that new forms of distancing are encouraged by the growing significance of financial markets in global agrifood value chains. This dynamic has a substantial impact on food system outcomes and ultimately complicates efforts to scale up small-scale local agricultural models that are more sustainable.     

Atmospheric nitrogen compounds-issues related to agricultural systems

Workable pollution abatement policies and effective legislation must be based on sound science. However, despite many years of research, there are still uncertainties about the effects of atmospheric nitrogen compounds on crops and other vegetation. This paper reviews the current state of knowledge of the main compounds, focussing on the concentrations and combinations of pollutants that occur in rural areas. The sources, concentrations and effects of oxidised, reduced and organic nitrogen compounds are considered in turn, then the effects of deposited nitrogen on ecosystems are discussed. Research priorities on the effects of deposited nitrogen in Europe and the USA are compared. Finally, the review leads to a list of issues for discussion and recommendations for research.     

Activity concentration of caesium-137 in agricultural soils

In this study, we measured 137Cs activity concentrations in the soil samples taken from agricultural lands in the Buyuk Menderes Basin in Turkey in 1997 and 1998. The soil samples were collected from 42 sites in this Basin. The activity concentration of 137Cs was found to range between 2.81+/-0.17 Bq.kg(-1) and 20.75+/-0.29 Bq.kg(-1). The effect of organic matter, clay, silt and sand contents and pH of the soil on the relative adsorption of the 137Cs on the soil surface were also studied.     

Determination of bioavailable rhenium fraction in agricultural soils

Rhenium (Re) mobility in agricultural soils was studied in order to obtain information relevant to (99)Tc mobility in soil-to-plant systems. Since water soluble Tc and Re are highly bioavailable, extraction of Re with water was carried out in addition to a total Re determination in the soils. The geometric means of total Re for paddy field, upland field and other soils were 0.34, 0.23, and 0.28 ng g(-1), respectively, while those of water soluble Re (<0.45 microm membrane filterable) were 0.053, 0.015 and 0.008 ng g(-1), respectively. There were no differences for total Re among soil uses; however, the water soluble Re/total Re ratio was significantly higher in paddy field soils (16%) than in other soil uses (6% for upland fields and 3% for other uses). Rhenium mobility and plant availability were higher in paddy fields than in other agricultural fields, and similar phenomena would be expected for (99)Tc.     

Ecological issues related to ozone: agricultural issues

Research on the effects of ozone on agricultural crops and agro-ecosystems is needed for the development of regional emission reduction strategies, to underpin practical recommendations aiming to increase the sustainability of agricultural land management in a changing environment, and to secure food supply in regions with rapidly growing populations. Major limitations in current knowledge exist in several areas: (1) Modelling of ozone transfer and specifically stomatal ozone uptake under variable environmental conditions, using robust and well-validated dynamic models that can be linked to large-scale photochemical models lack coverage. (2) Processes involved in the initial reactions of ozone with extracellular and cellular components after entry through the stomata, and identification of key chemical species and their role in detoxification require additional study. (3) Scaling the effects from the level of individual cells to the whole-plant requires, for instance, a better understanding of the effects of ozone on carbon transport within the plant. (4) Implications of long-term ozone effects on community and whole-ecosystem level processes, with an emphasis on crop quality, element cycling and carbon sequestration, and biodiversity of pastures and rangelands require renewed efforts.The UNECE Convention on Long Range Trans-boundary Air Pollution shows, for example, that policy decisions may require the use of integrated assessment models. These models depend on quantitative exposure-response information to link quantitative effects at each level of organization to an effective ozone dose (i.e., the balance between the rate of ozone uptake by the foliage and the rate of ozone detoxification). In order to be effective in a policy, or technological context, results from future research must be funnelled into an appropriate knowledge transfer scheme. This requires data synthesis, up-scaling, and spatial aggregation. At the research level, interactions must be considered between the effects of ozone and factors that are either directly manipulated by man through crop management, or indirectly changed. The latter include elevated atmospheric CO(2), particulate matter, other pollutants such as nitrogen oxides, UV-B radiation, climate and associated soil moisture conditions.     

Reuse of mining wastewater in agricultural activities in Jordan

A pilot study was completed in the Al-Abyad area near phosphate mining activity in Jordan. Six plots of 50 m² each were planted with two types of plant species (Zea mays spp. and Medicago lupulina spp.) and irrigated using three types of water (fresh groundwater, mine wastewater, and hydride water consisting of 50% fresh and 50% mine wastewater) to investigate the suitability of utilizing mine wastewater for food production in the area. Water, soil and plant sampling was completed for each plot over different time intervals and analyzed for heavy metal (Cr⁺⁶, Ni⁺², Zn⁺² and Pb⁺²) in addition to major ionic composition of the water used for irrigation. Crop yield was estimated at the end of the experiment. Plots irrigated with mine wastewater showed slightly higher heavy metals concentrations and soil salinity during the experiment period was higher for plots irrigated with mine wastewater compared to plots irrigated with fresh water, and it was uniform through the upper 45 cm of the soil profile due to the high amount of irrigation water used during the experiment. Crop yield was inversely proportional to salinity as an increase of salinity by 2-folds resulted in reducing yield by almost 50%. However, no risk of heavy metals contamination was found in plants and soil. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

The economic,environmental and agricultural land use effects in the European Union of agricultural labour subsidies under the Common Agricultural Policy

In this study, we assessed the economic, environmental and agricultural land use impacts in the EU of a 20% reduction in the Pillar I budget of the Common Agricultural Policy (CAP) of the European Union (EU) and spending the saved money via a subsidy on labour in primary agriculture. The impact of such a policy has been assessed with a computable general equilibrium (CGE) model and a partial equilibrium (PE) model. It is concluded that reallocation of Pillar I budgets to a coupled agricultural labour subsidy increased employment in agriculture, especially in agricultural sectors and regions that are relatively labour intensive. Average employment in agriculture in the EU increased with 1.6% in the CGE model and with 0.6% in the PE model. Agricultural production and environmental emissions from agriculture increased as well. At the same time, prices of agricultural outputs decreased. Value added including subsidies increased for agricultural labour, but total value added in agriculture decreased. The latter was especially explained by decreased land prices and land-related value added. Measured in terms of equivalent variation, total welfare in the EU decreased. Welfare costs equalled about 1400 € per full-time work equivalent in agriculture extra. These results show that policy makers should weigh carefully the pros and cons of the direct and indirect overall economic, environmental and land use impacts of a subsidy on agricultural labour at the expense of the Pillar I budget of the EU CAP.

     

Quantifying effects of oxidant air pollutants on agricultural crops

Estimating risks of air pollution damage to agricultural crops requires identifying crop location and size, likely doses, models for translating dose to response, and measures of response appropriate for economic analysis. Assessment of risk requires compatible data sets for each of these variables. Analysis of air pollution mixtures suggests that oxidant crop damage is caused by three compounds: ozone, nitrogen oxides, and peroxyacetylnitrates. The phytotoxicity of ozone, the most prevalent photochemical oxidant, has been studied more extensively than the other two oxidants, and its effects on vegetation are best understood. Response of vegetation to air pollutants was first characterized by foliar or visible injury. Subsequent research indicated that foliar injury did not translate directly into reduced plant growth or yield, which can be measured. Response to air pollutants may be influenced by physical, biological, and environmental factors. Inherent genetic resistance is probably the most important single factor affecting plant response, although environmental factors influencing stomatal aperture may also be important. For several crops open-top chamber studies and cross sectional analyses of field data provide adequate information to develop dose-response functions. All of these studies have both strengths and weaknesses. Although a number of different models exist for selected crops, there is no single biological or statistical criterion which identifies the best or most accurate model.     

人工增雨与农业水资源开发探讨

在分析我国水资源状况的基础上,针对我国淡水资源短缺问题,提出要充分利用人工增雨手段,开发空中水资源,以缓解水资源的短缺。     

环境分权、环境规制对农业面源污染的影响

环境规制是实现农业面源污染减排的重要手段,而科学合理地划分环境管理权力是夯实环境规制减排绩效的制度基础。厘清环境分权、环境规制与农业面源污染三者之间的关系对优化环境管理体制和促进农业绿色发展具有重要的理论与现实意义。鉴于此,文章将环境规制、环境分权和农业面源污染纳入同一分析框架,基于2005—2017年省际面板数据,构建动态面板模型和面板门槛模型,实证考察了环境分权、环境规制与农业面源污染的内在联系。研究结果显示:①环境规制是抑制农业面源污染的重要手段;环境分权、环境监察分权和环境监测分权对农业面源污染具有显著的正向作用,环境行政分权对农业面源污染则表现为负向作用。②环境事务管理权力的下放将恶化环境规制的农业面源污染减排效应,引发“绿色悖论”效应,其中环境监察分权和环境监测分权的影响尤为突出。③从区域层面来看,中西部地区环境事务管理权力下放引发的“绿色悖论”效应显著,而东部地区则不显著。④环境规制对农业面源污染的影响随环境分权程度的变化呈现出门槛特征。伴随环境分权程度的提高,环境规制对农业面源污染的影响由“援助之手”转为“攫取之手”。因此,为解决日益严重的农业面源污染,应制定差异化的环境分权策略。一方面,环境行政权力应适当下放,而环境监察和环境监测权力要逐步上移;另一方面,进一步压缩中西部地区环境政策自由裁量空间,加大农业环境考核与监督力度。同时,建立长期动态农业面源污染监测体系,形成联防联控治理格局。