Agricultural specialization and height in ancient and medieval Europe

Land per capita was one important determinant of height in the Malthusian world 0 to 1800 A.D. A second factor was specialization in milk cattle agriculture. It had two positive effects on human stature: first, proximity to protein production resulted in a very low local shadow price of milk, as this important foodstuff could not be transported easily. Second, this low price resulted in a low inequality of nutritional status, whereas, for example, tradable pork contributed to nutritional inequality. For this study, we used a data set of more than two million animal bones to measure specialization in cattle and its impact on stature.     

对新疆农民专业合作组织发展的思考

建立农民专业合作组织是农村发展现代农业、走向市场经济的必然要求。目前,新疆各种新型的农民专业合作组织不断涌现,并在引导农户进入市场、提高农业效益、增加农民收入、保护农民利益等方面发挥着愈来愈显著的作用。但是新疆的农民专业合作组织在其发展过程中,因受农户素质、运营资金、合作规模等因素的制约发展缓慢。本文对此进行了分析,并提出了几点建议。     

Ecosystem services and dis-services to agriculture

Agricultural ecosystems are actively managed by humans to optimize the provision of food, fiber, and fuel. These ecosystem services from agriculture, classified as provisioning services by the recent Millennium Ecosystem Assessment, depend in turn upon a web of supporting and regulating services as inputs to production (e.g., soil fertility and pollination). Agriculture also receives ecosystem dis-services that reduce productivity or increase production costs (e.g., herbivory and competition for water and nutrients by undesired species). The flows of these services and dis-services directly depend on how agricultural ecosystems are managed and upon the diversity, composition, and functioning of remaining natural ecosystems in the landscape. Managing agricultural landscapes to provide sufficient supporting and regulating ecosystem services and fewer dis-services will require research that is policy-relevant, multidisciplinary and collaborative. This paper focuses on how ecosystem services contribute to agricultural productivity and how ecosystem dis-services detract from it. We first describe the major services and dis-services as well as their key mediators. We then explore the importance of scale and economic externalities for the management of ecosystem service provision to agriculture. Finally, we discuss outstanding issues in regard to improving the management of ecosystem services and dis-services to agriculture.     

Valuing deer hunting ecosystem services from farm landscapes

Agricultural land provides a wide variety ecosystem services to individuals. These agroecosystem services include wildlife and biodiversity, which in turn support recreational opportunities such as hunting and wildlife viewing. Using the random utility travel cost model, we provide an estimate to illustrate the potential value of the white-tailed deer (Odocoileus virginianus) provisioning and recreational services provided by these ecosystems to deer hunters, as well as the value of providing deer hunters public access to a percentage of agricultural land.     

Reducing climate change impacts on agriculture: Global and regional effects of mitigation, 2000–2080

What are the implications for agriculture of mitigating greenhouse gas emissions? By when and by how much are impacts reduced? Where does it matter most? We investigated these questions within the new A2 emission scenario, recently developed at the International Institute of Applied Systems Analysis with revised population and gross domestic product projections. Coupling an agro-ecological model to a global food trade model, two distinct sets of climate simulations were analyzed: 1) A non-mitigated scenario, with atmospheric CO₂ concentrations over 800 ppm by 2100; and 2) A mitigation scenario, with CO₂ concentrations stabilized at 550 ppm by 2100. Impacts of climate change on crop yield were evaluated for the period 1990–2080, then used as input for economic analyses. Key trends were computed over the 21st century for food demand, production and trade, focusing on potential monetary (aggregate value added) and human (risk of hunger) impacts. The results from this study suggested that mitigation could positively impact agriculture. With mitigation, global costs of climate change, though relatively small in absolute amounts, were reduced by 75–100%; and the number of additional people at risk of malnutrition was reduced by 80–95%. Significant geographic and temporal differences were found. Regional effects often diverged from global net results, with some regions worse off under mitigation compared to the unmitigated case.     

天津发展都市农业有待破解的瓶颈性难题

通过对津京沪农业的横向比较与自身农业的纵向比较，天津农业经济结构、农民文化程度、农民收入及农村基础建设等方面，存在诸多问题。为了缩小城乡差距，提高农民收入，建设社会主义新农村，应通过实行惠农政策，改善农村基础公共设施，支持农村教育，提高农村医疗水平，坚持科技富农，推进乡镇企业产业化．最终实现科技化、产业化和生态化的都市农业。     

整合财政支农资金的模式构建

由于历史和体制原因,我国财政支持"三农"投入存在高运行成本、多重代理、信息不对称及效率低下等问题,严重影响支农资金的使用效应和政策效应。本文在分析我国财政支农资金使用现状的基础上,提出了整合财政支农资金的基本构想。     

财政支出对西部农业经济增长的效应分析

以财政作为西部农业的投资主体,运用统计方法分析财政支农支出与西部农业经济之间的相关关系,探讨目前我国财政支农政策存在的问题,从而对我国财政如何更有效地支持西部农业经济发展提供参考。     

美国农业财政补贴政策的经验与启示

美国农业财政补贴政策对美国的农业发展作出了重要贡献。在多年的农业补贴实践中,美国形成了较为完备的农业补贴体系,积累了丰富的经验,值得我们借鉴。但是在有些方面还要结合中国的情况,不断探索适合中国国情的农业补贴制度。     

农民对待“三农”问题态度的现实思考

“三农”问题是当前中国问题的“重中之重”,然而近几年的一系列改革并没有真正使农民的生活状况得到改善,农民对每一次出台的政策,在欣喜之余还是失望和无奈,农民对待“三农”问题的态度变得比较消极。因此,要想真正解决“三农问题”,必须要合并税费,规范征收;改革乡镇体制,完善村民自治;缩小城乡差距,加快城镇化进程。