水肥耦合效应对保护地土壤硝态氮运移的影响

采用二次回归正交旋转组合设计，研究了水肥耦合效应对保护地土壤硝态氮运移的影响。结果表明，0—20cm土层硝态氮含量主要受灌水和施氮的影响，且灌水影响程度大于施氮，灌水与0—20cm土层硝态氮含量呈负相关，而与施氮呈正相关。20—40cm土层和40—60cm土层硝态氮也主要受灌水和施氮的影响，但施氮影响程度大于灌水。灌水和施氮对0—20cm土层硝态氮含量影响有相互拮抗作用。施磷对3个层次土壤硝态氮含量影响都很小。     

水肥耦合效应对保护地土壤硝态氮运移的影响

采用二次回归正交旋转组合设计,研究了水肥耦合效应对保护地土壤硝态氮运移的影响。结果表明,0—20cm土层硝态氮含量主要受灌水和施氮的影响,且灌水影响程度大于施氮,灌水与0—20cm土层硝态氮含量呈负相关,而与施氮呈正相关。20—40cm土层和40—60cm土层硝态氮也主要受灌水和施氮的影响,但施氮影响程度大于灌水。灌水和施氮对0—20cm土层硝态氮含量影响有相互拮抗作用。施磷对3个层次土壤硝态氮含量影响都很小。     

水肥优化耦合下设施青菜的养分吸收和干物质积累规律

为明确最佳灌溉施肥条件下设施青菜对氮、磷、钾养分的吸收规律,通过田间试验研究了微喷灌条件下设施青菜在不同生育期氮、磷、钾养分吸收积累和干物质积累的特征以及与养分累积吸收量的相关性。结果表明,在不同生育期,设施青菜氮、磷、钾养分含量存在显著差异(P<0.05)。旺长期青菜体内氮、磷、钾含量均显著高于幼苗期(P<0.05),进入成熟期后略有降低。从养分吸收速率来看,旺长期3种养分的吸收速率均最大,幼苗期和成熟期吸收速率较小。3种养分的吸收速率从大到小依次为钾、氮和磷。整个生育期养分累积量和干物质累积量从大到小依次为旺长期、幼苗期和成熟期。此外,设施青菜体内养分吸收量与干物质积累呈显著正相关(P<0.05),水肥优化耦合条件下氮、磷、钾3要素之间存在着相互促进吸收的正相关作用。     

水肥管理对稻田土壤甲烷和氧化亚氮排放的影响

就稻田水肥管理对甲烷和氧化亚氮排放的影响研究进行了综述。文献分析表明,甲烷和氧化亚氮的排放条件存在明显的反位关系,即有利于甲烷排放的水分条件往往不利于氧化亚氮的排放。稻田温室气体的排放与水分管理的历史有明显的关系,不同的肥料施用对甲烷和氧化亚氮排放影响的机制不同。因此,要真正有效地控制温室气体的排放必须首先弄清甲烷和氧化亚氮在不同条件下的排放关系。     

不同灌水条件下冬小麦的产量、水分利用与氮素利用特点

了解不同灌水量(次数)处理条件下华北平原地区冬小麦的产量形成、氮素利用与水分利用的特点.在大田相同的施肥量与施肥方式、播前浇底墒水750m3.hm-2条件下,设置春季不灌水、春季灌2水(拔节+开花)和春季灌4水(起身+孕穗+开花+灌浆)3个水分处理(每次灌水定额750 m3.hm-2),分析了不同灌水量(次数)对植株氮素吸收利用、产量、土壤水分动态及利用效率的影响.冬小麦生育期内总耗水量和开花后耗水量均表现为随灌水次数(量)增加而增大的趋势,但耗土壤水量却随灌水增加而显著减少.春季灌水处理的经济产量均显著高于春季不灌水处理,但春灌2水和春灌4水之间无显著差异.水分利用效率(WUE)在春不灌水和春灌2水间无显著差异.但它们均显著高于春季灌4水处理.植株总吸氮量均随着灌水次数(灌水量)的增加而呈现出上升的趋势,春灌2水和灌4水处理的总吸氮量无显著差异,但它们均显著大于不灌水处理.氮素生理效率和氮素收获指数随灌水量(次数)增加略有下降,不同灌水处理之间并无显著差异.春灌2水处理相对春季不灌水处理显著提高了经济产量和植株总吸氮量,水分利用效率并没有明显下降;与春灌4水处理相比,经济产量和植株总吸氮量没有明显降低.但水分利用效率和水分边际效益显著提高.冬小麦节水栽培(春灌2水)有利于节水、氮素高效利用和高产的实现.     

间歇性遮光对棉花蒸腾特性及水分利用效率的影响

以陆地棉（中棉所２３号）为供试材料,应用盆栽试验,设计了３种间歇性遮光水平,即不遮光（ＣＫ）、遮光４０％（处理 Ⅰ）、遮光 ７５％（处理 Ⅱ）,分析了间歇性遮光对棉花不同生育期晴天中午净光合速率、蒸腾速率、气孔导度、叶水势和水分利用效率的影响。结果表明,（１）间歇性遮光降低棉花蕾期、花期、铃期的净光合速率和水分利用效率,下降幅度是处理Ⅱ＞处理Ⅰ;（２）降低花期、铃期的蒸腾速率和气孔导度,但使蕾期的蒸腾速率和气孔导度增加;（３）对中午叶水势几乎没有影响。     

保水剂对番茄生长及水分利用效率的影响

在砂与木屑复合基质中加入不同用量的保水剂,测定基质物理性状,并进行不同水分处理条件下番茄盆栽试验,以研究保水剂对番茄生长及水分利用效率的影响。结果表明:在每1 L基质分别加入1、2、4、8 g保水剂时,与对照(未加保水剂)相比,基质持水量分别增加16.35%、34.00%、61.29%和135.16%,容重分别降低3.61%、5.37%、9.42%和14.64%;在水分耗竭试验中,番茄萎蔫天数分别延长13.92%、22.79%、31.65%和45.5%,干物质量分别增加7.90%、21.60%、57.08%、179.50%,株高、叶片数、茎粗、鲜质量也都随保水剂用量的增加而明显增加;在基质相对水分质量分数分别为55%、70%、85%及100%4种处理下的番茄水分胁迫试验中,每1 L基质施用2 g保水剂时,与对照(未加保水剂)相比,水分利用效率分别提高29.93%、28.06%、14.36%、7.42%,株高、生物量也随水分胁迫程度加重而明显提高。     

广东省节水与旱作农业基本情况调查报告

全省节水与旱作农业基本情况调查结果表明：干旱缺水是影响旱坡地作物产量提高的主要因子.近年来.我省采用节水灌溉技术、节水耕作技术、优化种植结构等措施,提高了水资源的利用率.今后,在旱坡地上开发节水高效农业大有潜力.     

基于RS和GIS的长沙城市热岛效应与TSP污染耦合关系

城市热岛效应反映了城市化发展对城市环境的影响,是影响城市生态环境的一个重要因素。文章以长沙市为例,利用3S技术与传统技术相结合对大气中总悬浮颗粒物(TSP)在城市热岛中的作用与贡献进行了研究。结果表明,长沙城市热岛效应与TSP污染在空间与时间分布上都具有耦合关系。采用RS和GIS技术可以从空间上对TSP在城市热岛中的贡献进行研究。长沙市TSP污染的分布特征和热岛强度分布状况基本一致,都是由市中心往外逐渐减轻。TSP高值区,城区呈高温区;TSP低值区,城区呈低温区。采用长沙市TSP高值区、TSP低值区的两个监测点2002年逐月TSP监测数据及相应气象统计数据,从时间上对TSP污染与城市热岛效应进行了相关性研究,长沙市TSP污染与热岛强度在年度分布上存在正相关关系。随着长沙城市建设和城市化速度的加快,城市热岛强度有逐年增强的趋势。3S技术与传统技术相结合,使科学研究更客观、准确。3S技术用于中尺度的区域环境质量调查,可实现空间区域的定量表达,而传统技术获取的环境背景数据,则从微观上对空间数据的准确性进行验证。     

毛白杨杂种无性系稳定碳同位素值的特征及其水分利用效率

2008年在北京林业大学对9个毛白杨(Populus tomentosa)杂种无性系苗木生长不同时期的叶片、小枝、根的碳同位素δ~(13)C和瞬时水分利用效率WUEi的差异进行研究,分析不同无性系间δ~(13)C与瞬时水分利用效率WUEi的相互关系,目的在于探求δ~(13)C在筛选高水分利用效率毛白杨杂种无性系中的应用价值.结果表明:不同生长时期叶片δ~(13)C值表现为7月<8月<10月<9月,小枝δ~(13)C值表现为8月<9月<10月,叶片δ~(13)C值、小枝δ~(13)C值在不同时期和不同无性系间的差异均达显著水平,无性系间的差异是引起δ~(13)C值变化的主要因素.不同部位碳同位素比值表现为叶片<小枝<根,毛白杨杂种无性系δ~(13)C值在不同部位和无性系间差异均达显著水平,部位间的差异是引起δ~(13)C值变化的主要因素.δ~(13)C值较高的无性系30、83、BL5的WUEi也较高,δ~(13)C值较低的无性系42、26、BT17的WUEi也较低,且不同时期δ~(13)C和WUEi呈较强的正相关,相关系数分别为0.766、0.872、0.675,高δ~(13)C可以作为筛选高WUEi毛白杨的有效指标,且在苗木生长旺盛时期选育能得到更为可靠的结果.     

科学施肥与农业生产可持续发展

化肥的施用，实现了农业的增产，一百多年来为解决中国人民的温饱问题做出了重大贡献。肥料仍然是粮食安全的重要保障。但不合理施用化肥造成环境污染和食品安全问题，使人们产生了对化肥的错误认识。文章认为必须树立起科学施肥的观念，努力提高化肥利用率，形成有机、无机肥料合理配合使用的格局，促进农业生产可持续发展。此外，还认为应加强肥料市场管理，使之有法可依，并能迎接入世的挑战。     

洞庭湖区的湖垸农业与可持续发展对策

在调查分析洞庭湖区围湖垦殖和湖垸农业形成的历史的基础上，归纳了湖垸农业面临的生态环境问题：洪涝灾害发生频率加大；水面减少，生物多样性降低；环境污染严重，湿地生态功能衰退；土壤退化和潜育化严重；血吸虫病死灰复燃。并结合已有的经验，提出了湖垸农业可持续发展的对策措施：认真实施生态保护工程，减少泥沙淤积；调整湖垸农业结构，建立有利于避灾、减灾新模式；退田还湖，发展替代农业，发展莲藕、籽藕、茭白等水生经济植物种植；与企业结合，发展油菜、马铃薯、亚麻等工业原料作物；利用欧美杨耐涝性强的特点，在地势较高的季节性淹没的洲滩地，发展以林为主的林农复合经营模式，湖洲草地发展草食畜禽替代模式。     

微生物资源的开发利用与农业可持续发展

对微生物资源在农业可持续发展中的作用及其合理开发利用进行了阐述和总结。认为微生物作为一种宝贵的资源,它与农业可持续发展的关系十分密切,它在土壤肥力的提高与保持、营养元素的转化、环境净化与生态系统的平衡等方面起着极其重要的作用。因此,加强以微生物肥料、微生物农药、微生物食品、微生物饲料、环境激素和环境工程微生物等为核心的农业清洁生产技术的研究与开发利用将具有广阔的应用前景。微生物农业即所谓的"白色农业"将成为未来农业可持续发展的重要方向之一。     

Water shortage: a serious problem in sustainable development of China

SUMMARY

Water crises have occurred in more than 400 cities in China at the beginning of 2000. Investigation and statistical data suggest that there are five main problems in the management and utilization of water resources in China. These are (1) insufficient capacity and inhomogeneous space-time distribution of natural resources, (2) outdated construction of water conservancy projects and supply engineering, (3) unreasonable industrial water consumption, (4) increased water pollution and (5) incomplete management of the river basin and waterworks in city. It is necessary to take steps corresponding to the above-mentioned reasons to mitigate and even dispel the pressure on water resources for sustainable development of China as quickly as possible.     

On measuring sustainable development indicators

Sustainable development, as proposed by the Brundtland Report, requires carefully managed change to improve environmental and economic conditions as well as the quality of life for all people. Some of the problems involved in this demanding challenge faced by individuals, local communities, nations and the international community are discussed. In particular, nine indicators of sustainable development—gleaned from economic, socioeconomic and environmental studies—are critically reviewed. It is argued that a programme of detailed theoretical and empirical research is needed to develop a series of measures or indicators of sustainable development for strategic decision making and detailed environmental management.     

Moving towards sustainable development: rhetoric,policy and reality of ecological agriculture in China

Past decades have witnessed the rise of sustainable agriculture movements throughout the world. In parallel with this international trend, ecological agriculture (with essential goals of food security, rural employment, poverty alleviation, natural resource management and environmental protection) has been advocated as a workable approach for the realization of sustainable agriculture in China. Two decades of ecological agricultural development have shown that it not only gained legitimacy at the senior policy level but also became a focus of scientific research in fields such as ecological economics, ecology, and agricultural and environmental sciences. However, this endeavour is hardly known in the West and little attention has been paid so far to examining the broader politico-economic and sociocultural contexts within which it has evolved. This paper attempts to provide a general review of the emerging background, development history, policy initiatives and recent tendencies of ecological agriculture. In addition, the extant problems and potential contributions of this alternative practice to China's sustainable agricultural development are discussed. The purpose of this study is to identify the gap between the policy rhetoric and practical implementation of Chinese ecological agriculture and therefore to facilitate its moving towards sustainable development.     

Towards a co-evolutionary framework for implementing sustainable development

SUMMARY

A quantitative method which can be used to gauge the sustainability of existing socio-cultural, economic and environmental constructs is proposed. An underlying assumption of the approach is that a co-evolutionary relationship exists between social, cultural, economic and environmental systems and that these cannot be addressed in a reductionist and deterministic manner. The method focuses on both broad trends and patterns of variance in a multivariate data matrix, it allows the identification of dominant trends as well as underlying tensions, does not treat socio-cultural, economic and environmental heterogeneity as statistical noise and can be applied at different administrative scales. Furthermore, it may be used to identify potential sources of human insecurity, factors that may affect the probability of positive human survival, developmental patterns at odds with the established values system of civil society that can be targeted for political action, and to inform public debate. In addition, the method can be used to identify unexpected synergies between variables and may serve as an early warning system for regional planners.     

Using the sustainable development goals towards a better understanding of sustainability challenges

The United Nations General Assembly agreed and approved in September 2015 the document ‘2030 Agenda for Sustainable Development’, which contains a set of measures aiming to balance economic progress and protection of the environment, whilst at the same time remain aware of the need to address the many disparities still seen between industrialised and developing countries. The Agenda document consists of 17 Sustainable Development Goals (SDGs), which among many other tasks, intend to eradicate poverty and create better health conditions in both developed and developing countries. But despite the need for and the relevance of the SDGs, it is unclear how they may help to address present and future sustainability challenges. Based on the need to shed some light on such a relationship, this paper describes each of the SDGs, and offers an analysis of the extent to which their implementation may offer support to ongoing attempts to handle some of the pressing problems seen in pursuing sustainable development. Three case studies are presented to show in practice how best the SDGs can be handled. The paper concludes that the process of implementing the SDGs offers unrivalled opportunities to advance equal opportunity and foster economic empowerment, helping countries to promote the cause of sustainable development in their territories, hence benefiting their populations.     

Indicators of sustainability as a tool in agricultural development: partitioning scientific and participatory processes

SUMMARY

Sustainable indicators have become popular tools by which policymakers can assess progress towards a more sustainable agriculture. Varying approaches to defining sustainability lead to disagreement about the value of indicators and yet some form of measurement is required so that society can judge the effects of policy. Environmental and social problems and their causes span national boundaries. An international framework for assessing agricultural activities, their effects and the pressures that drive those activities is therefore required. However, a guiding principle of the UN Agenda for Sustainable Development is that global problems require local action. Thus, indicators must provide information for policymakers as well as guidance for farmers and other practitioners. Many indicator programmes currently proposed do not provide this level of guidance as no evaluation as to what level of activity is sustainable has been agreed. A model is presented, to show how scientific and political or participatory approaches may be combined to meet the multiple objectives of involving people, maintaining scientific integrity and providing guidance for policymakers and practitioners alike.     

Emerging,diverging and converging paradigms on sustainable development

Sustainable development has been used in various contexts by theoreticians and practitioners from a number of disciplines. This review explores some of these contexts from basic and applied ecological sciences, social sciences and philosophical works. It is concluded that there is a need to develop a theoretical paradigm that helps to explain the reasons underlying human resource use—a fundamental question that has been ignored in many other studies. A theoretical, evolutionary approach and several premises derived from this approach are offered. The theoretical framework suggests that societal scale, social structure, interrelatedness of individuals, and reciprocal relations between individuals may all be important in determining the types of management programmes that promote sustainable resource use by humans. Examples of solutions to various sustainability issues at different scales, based on different kinds of incentive structures, are also presented.