Global change and agricultural management options for groundwater sustainability

According to the general circulation models (CGMs) for future climate projections, a temperature increase, precipitation decrease, and an increase in the variability of extreme events may be expected in the future, likely reducing available water resources. For the western Mediterranean, future climate change projections indicate that temperature increase may range from 1.5 °C to 3.6 °C, and the precipitation decline will reach between 10% and 20%, which may result in a significant reduction of natural groundwater recharge. With the use of modelling tools, the amount of groundwater recharge under different climate change scenarios and varying agricultural management practices can be predicted, and water budget attributes can be estimated, which may allow for quantifying impacts, and assist in defining adaptation strategies. For the Inca–Sa Pobla basin (Balearic Islands, Spain), under future climate change projections, agricultural management alternatives of crop type distribution and irrigation demands are required for planned adaptation strategies. In the area, where irrigation water for agricultural practices originates from groundwater resources, adaptation measures based on a change from mixed crops to potatoes and a 20% decrease of agricultural land cultivation have proven to be efficient for the hydrologic system and associated wetland sustainability.     

Linking models for assessing agricultural land use change

The ex-ante assessment of the likely impacts of policy changes and technological innovations on agriculture can provide insight into policy effects on land use and other resources and inform discussion on the desirability of such changes. Integrated assessment and modeling (IAM) is an approach that can be used for ex-ante assessment. It may combine several quantitative models representing different processes and scales into a framework for integrated assessment to allow for multi scale analysis of environmental, economic and social issues. IAM is a challenging task as models from different disciplines have a different representation of data, space and time. The aim of this paper is to describe our strategy to conceptually, semantically and technically integrate a chain of models from different domains to assess land use changes. The models that were linked are based on different modeling techniques (e.g. optimization, simulation, estimation) and operate on different time and spatial scales. The conceptual integration to ensure consistent linkage of simulated processes and scales required modelers representing the different models to clarify the data exchanged and interlinking of modeling methodologies across scales. For semantic integration, ontologies provided a way to rigorously define conceptualizations that can be easily shared between various disciplines. Finally, for technical integration, OpenMI was used and supplemented with the information from ontologies. In our case, explicitly tackling the challenge of semantic, conceptual and technical integration of models forced researchers to clarify the assumptions of their model interfaces, which helped to document the model linkage and to efficiently run models together. The linked models can now easily be used for integrated assessments of policy changes, technological innovations and societal and biophysical changes.     

覆膜补灌对云南春作马铃薯耗水特性及生长的影响

目的研究集雨补灌条件下,春马铃薯—夏蚕豆复种(薯豆复种)+豆秆还田对土壤养分变化及细菌群落结构的影响。方法以薯豆复种+豆秆还田、马铃薯种后空闲以及马铃薯连作土壤为研究对象,测定土壤理化性质;采用Illumina NovaSeq PE250对土壤细菌16S V3~V4区域进行高通量测序。结果与常规栽培模式相比,集雨补灌条件下,春作马铃薯提前75~76 d出苗,提前43~74 d收获,避开了晚疫病危害,滇薯23、滇薯47和青薯9号的产量分别增加28 953.0、8 571.0和28 570.5 kg/hm²。与马铃薯连作相比,薯豆复种+豆秆还田的土壤pH值增加0.17,有机质含量增加0.35%,全氮含量增加0.02%,有效氮含量增加43.6 mg/kg,有效钾含量增加51.5 mg/kg。与马铃薯种后空闲相比,薯豆复种+豆秆还田的土壤pH值增加0.14,有机质含量增加0.33%,全氮含量增加0.02%,全磷含量增加0.02%,有效氮含量增加39.8 mg/kg。薯豆复种+豆秆还田模式下,土壤中放线菌门、芽单胞菌门和鞘氨醇单胞菌属相对丰度高于马铃薯种后空闲模式和连作模式,但连作模式下土壤酸杆菌门丰度更高。相关性分析表明：土壤pH以及全磷和全钾含量是驱动细菌门丰度变化的主要环境因子。结论薯豆复种+豆秆还田可提高土壤肥力、减缓土壤酸化、增加土壤有益细菌门和属的相对丰度,而马铃薯连作会降低土壤pH和减少有益细菌;集雨补灌春作马铃薯收后复种夏蚕豆可增加复种指数,提高土地利用效率,改善土壤营养状况和细菌群落结构,减轻马铃薯连作障碍。     

洛桑试验站的长期定位试验:简介及体会

英国洛桑试验站的7个长期定位试验已经连续进行了150～170年,这些试验为农学、土壤学、植物营养学、生态学与环境科学的发展做出了重要贡献,被称为"经典试验"。本文简略地介绍这些试验的历史、部分成果及个人体会。试验结果揭示了农业生态系统长期的变化趋势,尤其是作物产量、元素与污染物循环、生物多样性等变化趋势,对探索农业可持续性有重要的指导意义。长期定位试验起到短期试验无法替代的作用,样品的长期保存与多学科交叉合作是挖掘长期定位试验价值的关键。     

Not just what, but how: Creating agricultural sustainability and food security by changing Canada's agricultural policy making process

Agriculture has been enormously productive in recent decades. The main problem is that fragmentation of issues, knowledge, and responsibilities has hidden the costs associated with this success. These are mainly environmental, social, and health costs, which have been assigned to other ministries, with their own histories unconnected to agriculture. Now that agricultural policy has achieved its success, its costs are becoming apparent. The current system is preoccupied with traditional views of competitiveness and efficiency. Policies, programs, and regulations are organized to support specific commodities, not farming and food systems. Responsibilities are extremely fragmented and frequently uncoordinated. In this environment, the focus on nourishment, food security, and environmental sustainability is subordinated to economic issues.The future lies in reorienting agricultural policy away from maximum production and towards sustainability. We propose a major transformation of the policy making apparatus in order to shift the focus of the system towards nourishment, food security, and sustainability. A new policy making system must be built on the themes of: integrated responsibilities and activities; emphasis on macro-policy; transdisciplinary policy development; proximity of policy makers to the diverse groups affected by problems needing resolution; food systems policy.The design principles for such a new system are taken from the theory of food security and ecology. Using these principles, we design a new provincial department of food and food security, and test this design with two case studies.     

金融危机中农业发展面临的挑战与中国东盟农业合作

分析了金融危机给农业发展带来的挑战,探讨了中国与东盟农业合作的主要内容。金融危机给农业发展带来挑战:农产品需求疲软,农产品价格下滑;农业保护主义抬头,农产品国际贸易受阻;企业开工不足,农村就业形势严峻;农民收入增长缓慢,农民生活改善受到影响。中国与东盟必须加强农业国际合作,才能有效抗击农业面临的严峻挑战。中国与东盟农业合作的主要内容是:加强农业政策协调,加强农业贸易合作,加强农业技术合作,加强农业资源合作,加强农业信息合作。     

气候变化与中国农业发展问题的研究

农业易受气候变化影响,气候变化及其引发的极端天气事情对中国农业发展造成的危害有日益加重的趋势。因此,应对气候变化已经成为我国农业发展面临的主要挑战之一,被列为我国政府保持我国农业持续稳定以及我国农业和农村经济持续发展的重要战略任务。文章从分析气候变化情况及其对农业气象的影响入手,分析了气候变化对中国农业发展的可能影响,并提出了农业应对气候变化的政策措施。     

Agent农业土地变化模型研究进展

农业土地变化是全球变化与可持续研究的热点,当前研究虽取得了长足进展,但仍存在诸多不足,集中表现在对农业土地系统复杂性与动态性的认识不够.近年来,基于Agent的农业土地变化研究(农业ABM/LUCC,Agent-based agricultural land change modeling)逐渐兴起,极大的丰富了传统研究的理论与方法,具体表现在:(1)农业ABM/LUCC将微观层面的人类个体行为整合进土地变化研究框架,有助于更加清楚的认识农业土地系统的“人类-自然”综合复杂性问题.(2)农业ABM/LUCC能够动态表达土地系统变化的内生反馈机制,有助于弥补传统的静态土地变化驱动机制分析的不足.(3)基于ABM/LUCC的农业土地利用格局动态研究是整合“人类-自然”综合研究的关键桥梁,农业ABM/LUCC能够与其他生物地球物理模型或经济模型动态嵌套,使多尺度、多维度综合模型研究成为可能.然而,农业ABM/LUCC研究也存在诸多挑战,如理论研究滞后于应用研究,大尺度应用难以开展,以及农户行为的模拟结果很难得到校验等.     

汇率变化对我国农业产业的影响——基于农业部门局部均衡模型

为研究汇率浮动与中国农产品市场波动之间的关系,采用全球农产品市场局部均衡模型,设定5种货币贬值和升值的情景方案,通过静态模拟方法,评估不同货币的汇率变化对中国农业产业的影响。结果显示,人民币贬值时,进口商品变的更加昂贵,进口减少,国内产品的需求增加,刺激国内产出增加。从具体产品来看,人民币贬值对稻谷、小麦、玉米、牛肉、猪肉和奶粉产量的影响较大。当人民币升值,中国农业受到的影响与贬值情况相反。主要农业贸易伙伴国货币汇率变动则首先影响该国产品的进出口量,进而影响产品的世界价格,再通过进出口将价格传导到中国,最终引起中国相关产品的生产、消费和贸易量的变动。中国受到较大影响的是从这些国家进口份额较大的产品,其中欧元、澳元、新西兰元和巴西雷亚尔汇率变动将主要引起中国牛肉、猪肉、奶粉、小麦和大豆进口量和产量的变化。     

Climate change record in subsurface temperatures: A global perspective

Analyses of underground temperature measurements from 358 boreholes in eastern North America, central Europe, southern Africa, and Australia indicate that, in the 20th century, the average surface temperature of Earth has increased by about 0.5 degreesC and that the 20th century has been the warmest of the past five centuries. The subsurface temperatures also indicate that Earth's mean surface temperature has increased by about 1.0 degreesC over the past five centuries. The geothermal data offer an independent confirmation of the unusual character of 20th-century climate that has emerged from recent multiproxy studies.     

入侵生态学最新研究动态

目的揭示紫茎泽兰和飞机草入侵对茶园昆虫群落结构和功能的影响,为深入研究植物入侵后茶园昆虫群落的演变机制及茶园生态管理措施选择提供科学参考。方法采用田间样地调查法,选取紫茎泽兰(Ageratina adenophora)和飞机草(Chromolaena odorata)入侵程度不同(未入侵、轻度入侵和重度入侵)的茶园群落作为研究样地,采用巴氏罐法(陷阱法)和黄板法采集各类型茶园群落地表昆虫,通过计算、比较Shannon-Wiener多样性指数、Simpson优势度指数、Pielou均匀度指数、Margalef丰富度指数和Jaccard相似性指数分析紫茎泽兰和飞机草入侵对茶园群落昆虫多样性的影响。结果在紫茎泽兰和飞机草不同入侵程度的3种类型茶园群落中共采集到昆虫标本8 033个,隶属于11目37科38种;其中,膜翅目(67.19%)、双翅目(15.25%)、弹尾目(5.39%)和同翅目(4.68%) 4个昆虫类群为优势类群,占昆虫标本总数的92.51%。随着紫茎泽兰和飞机草入侵的加剧,茶园群落中的昆虫种类和所属种的个体数都出现了不同程度的变化;茶园群落间昆虫的Shannon-Wiener多样性指数、Margalef丰富度指数以及Pielou均度指数显著降低(P<0.05), Simpson优势度指数显著升高(P<0.05);茶园群落间昆虫群落物种组成的相似性不断减小。结论紫茎泽兰和飞机草入侵对茶园群落昆虫群落结构和功能具有显著影响,使茶园的昆虫群落组成和结构发生改变,茶园群落中的昆虫多样性降低,茶园群落间昆虫群落物种组成的相似性不断减小。     

Mapping the road for voluntary change: Partnerships in agricultural extension

BIOS and BIFS are two California-based, small-scale alternative agricultural demonstration programs that define an applied Agriculture Partnership Model of extension. This model operates through a structure of local project leadership, a process of responsive farmer outreach and a primary goal of voluntary pesticide reduction. It reaches back to a Land Grant approach to extension of personal relationship, equal partnership, and collaborative learning. Overall findings from a systematic assessment of BIOS and BIFS imply that the operation and impacts of these two Agriculture Partnership Projects owe more to the model, approach, and values of the projects than to any specific farming or extension techniques. A model of local partnership and responsive, learner-centered outreach, operational values such as flexibility and relationship, and a balanced systems approach to farm management and project operation combine to create a promising organizational response to the rapidly changing regulatory, environmental, and political circumstances confronting conventional farmers in California. Though some farm advisors and field research specialists within the University of California Cooperative Extension have successfully used the projects to leverage decreasing Extension resources, increase their one-on-one contact with farmers, and learn new outreach and agricultural skills, others within that system are highly critical of the two projects. Organizational tension between Cooperative Extension and the quasi-university Partnership Projects largely reflects differences in fundamental beliefs and values about legitimate knowledge, learning processes, and effective teaching as well as primary goals for agricultural outreach. This revised version was published online in June 2006 with corrections to the Cover Date.     

全球变化研究热点——碳循环

40多年来,全世界的科研工作者已经在碳循环领域的各个方面做了大量的工作.本文总结了全球碳循环研究的最新进展,着重介绍了大气CO2浓度的变化及增长趋势,陆地生态系统和海洋对于大气CO2浓度变化及由此而引起的气候变化的反馈及其研究现状.同时,对许多固碳措施和技术方法也作了阐述.目前全球碳循环研究已经达到了系统集成的高度,因此集成研究将是21世纪碳循环研究的发展趋势.     

Fairtrade,certification, and labor: global and local tensions in improving conditions for agricultural workers

A growing number of multi-stakeholder initiatives seek to improve labor and environmental standards through third-party certification. Fairtrade, one of the most popular third-party certifications in the agro-food sector, is currently expanding its operations from its traditional base in commodities like coffee produced by peasant cooperatives to products like flowers produced by hired labor enterprises. My analysis reveals how Fairtrade’s engagement in the hired labor sector is shaped by the tensions between (1) traditional market and industrial conventions, rooted in price competition, bureaucratic efficiency, product standardization and certification and (2) alternative domestic and civic conventions, rooted in trust, personal ties, and concerns for societal wide benefits. At the global level, these tensions shape Fairtrade’s global standard setting as reflected in Fairtrade’s recently revised labor standards. At the local level, these tensions shape the varied impacts of certification on the ground as revealed through a case study of certified flower production in Ecuador.     

Ecosystem service supply and vulnerability to global change in Europe

Global change will alter the supply of ecosystem services that are vital for human well-being. To investigate ecosystem service supply during the 21st century, we used a range of ecosystem models and scenarios of climate and land-use change to conduct a Europe-wide assessment. Large changes in climate and land use typically resulted in large changes in ecosystem service supply. Some of these trends may be positive (for example, increases in forest area and productivity) or offer opportunities (for example, "surplus land" for agricultural extensification and bioenergy production). However, many changes increase vulnerability as a result of a decreasing supply of ecosystem services (for example, declining soil fertility, declining water availability, increasing risk of forest fires), especially in the Mediterranean and mountain regions.