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501.
有机无机肥料对农业环境影响述评 总被引:11,自引:0,他引:11
论述了有机肥在中国的使用情况和对农业生产的作用、化肥对农产品质量的影响、化肥对土壤肥力的贡献、有机肥和化肥对大气环境和水体的影响。目前人们在对化肥使用的认识上普遍存在误区,认为施用化肥一定会对环境产生污染,只有使用有机肥才能解决问题。中国是一个人口大国,今后在一个相当长的时间内,农业产品的生产在养分的投入上仍然需要以化肥为主,充分、合理、平衡的化肥投入不仅能满足人们对农产品数量上的需要,而且一定能满足人们对农产品品质的要求。化肥的合理施用可以改善和提高农产品品质,提高土壤有机质含量,改善土壤理化性质,减少温室气体的排放和水体污染。化肥本身是无害的,有害的是对化肥的不合理施用。在肥料问题上,今后需要关注
的应该是生产和使用更优质、更高效的化肥,推广科学合理的施肥技术,提高化肥的利用效率。 相似文献
502.
东中西部区域农业差异及其特征分析 总被引:1,自引:0,他引:1
我国东中西部区域农业发展水平的差异较大,认识这种差异的特征对于制定区域农业协调发展的战略决策具有重要意义。本文选择有关区域经济、社会、资源与环境方面的17项指标,采用主成分分析方法,对我国区域农业发展差异的现状进行了分析。结果表明,目前,东中西部农业发展的整体差异仍然很大,主要表现为人均农业产值和人均乡镇企业产值差异较大。而且,从1980~1995年农民人均纯收入的吉尼系数一直呈现增大趋势,说明区域差异呈持续扩大的态势。到1998年人均农业产值的吉尼系数高达0.43,已经高于国际警戒水平。对近10年东中西部乡镇企业产值变化的分析说明,自从实施西部开发战略以来,东中西部乡镇企业产值的比值已经由16:5.6:1.0变为4.5:2.1:1.0。显然西部开发促进了西部农业经济的发展,缩小了区域农业发展水平的差异。 相似文献
503.
Emmet F. Spencer Richard J. Ringwood Richard M. Brennan 《Journal of the American Water Resources Association》1975,11(4):836-847
ABSTRACT: The State of Louisiana created in 1972 the Deep Draft Harbor and Terminal Authority (commonly called Superport Authority) to plan, promote, and develop a deepwater (crude oil) terminal off the coast of Louisiana, and empowered it to establish an Authority development program to promote the economic and social welfare of its citizens. Simultaneously, the Authority was also charged with developing an environmental protection plan to preserve the environmental values of Louisiana's unique coastal marshland while permitting beneficial industrial and economic development. Consequently, in January 1974, an Environmental Protection Plan was promulgated, consisting of a series of regulations, design standards, and operating procedures aimed specifically at protecting the fragile estuarine environment of coastal Louisiana during the construction and ultimate operation of the superport. The paper describes the development of the Superport Authority's Environmental Protection Plan and the current status of the superport project. 相似文献
504.
K. Tybirk H. F. Alrøe P. Frederiksen 《Journal of Agricultural and Environmental Ethics》2004,17(3):249-274
Nature quality in relation to farming is a complex field. It involves different traditions and interests, different views of what nature is, and different ways of valuing nature. Furthermore there is a general lack of empirical data on many aspects of nature quality in the farmed landscape. In this paper we discuss nature quality from the perspective of organic farming, which has its own values and goals in relation to nature – the Ecologist View of Nature. This is in contrast to the Culturist View characteristic of much conventional agriculture and the Naturalist View characteristic of the traditional biological approach to nature quality. This threefold distinction forms a framework for exploration of nature quality criteria in the farmed landscape. The traditional work on nature quality has mainly focused on biological interests based on a Naturalist View of Nature. In this paper we will explore how criteria for nature quality based on the Ecologist View can be developed and thereby feed into the ongoing discussion of the development of the organic farming practices. We suggest additional criteria for nature quality based on an Ecologist View of Nature: biodiversity, habitat diversity, extent and structure, functional integrity of habitats and agro-ecosystems, landscape integrity, accessibility, and experientiality. The larger set of Naturalist and Ecologist criteria can provide a wider and more balanced basis for developing nature quality indicators that are relevant in the farmed landscapes. This broader approach to nature quality is also expected to benefit the general societal discussions and decisions on farming and nature. 相似文献
505.
Why slaughter? The cultural dimensions of Britain's foot and mouth disease control policy, 1892–2001
Abigail Woods 《Journal of Agricultural and Environmental Ethics》2004,17(4-5):341-362
In 1892, the British agricultural authorities introduced a policy of slaughtering animals infected with foot and mouth disease (FMD). This measure endured throughout the 20th century and formed a base line upon which officials superimposed the controversial "contiguous cull" policy during the devastating 2001 epidemic. Proponents of the slaughter frequently emphasized its capacity to eliminate FMD from Britain, and claimed that it was both cheaper and more effective than the alternative policies of isolation and vaccination. However, their discussions reveal that a less obvious but nonetheless important reason for maintaining the slaughter policy was the conviction that in its manner of operation and its outcomes, it benefited the state and status of the British nation. To its supporters, slaughter was far more than a method of disease control; it acted also as a moralizing and civilizing force, an indicator of veterinary ability and a "virility symbol" of British international leadership. This "cultural" rationale for FMD control by slaughter declined during the late 20th century and was wholly undermined by the 2001 epidemic, when extensive culling failed to convey the intended image of an organized, enlightened Britain. 相似文献
506.
基于“3S”技术构建农业灾害监测信息系统 总被引:25,自引:1,他引:24
本文从介绍遥感、地理信息系统、全球定位系统在建设农业灾害监测信息系统中的特点和优势出发,阐述了“3S”技术在农业灾害监测信息系统中的作用。在此基础上,提出了基于“3S”技术建设农业灾害监测信息系统的构想。 相似文献
507.
The degradation of water quality in many groundwaters of Europe is a major source of concern. Rises in turbidity and nitrate concentrations represent present or potential threats for the quality of drinking water in rural areas. They are for the most part a consequence of agricultural intensification which has considerably affected land cover and land use in recent decades. In our case-study (a karstic catchment) the mechanisms which explain changes in water quality, as far as turbidity and nitrate are concerned, result from a strong continuity between surface and underground waters. The karstic system of the Brionne Basin can be considered as both the focus of rapid horizontal flows (runoff, a rapid process in which rainwater reaches the spring directly through sinkholes) and slow vertical flows (leaching, in which rainwater filters through the soil to the spring). A hierarchical approach to the water pollution problem of the basin suggests that turbidity or nitrate concentrations peak during heavy rain episodes and are short-term events. In terms of management, this implies that the solution to water pollution caused by such events is also short-term and can therefore be addressed at a local scale. The rise of nitrate concentrations during the past twenty years is the main concern. The solution can only be found at a global scale (all the catchment area must be taken in account: land plots and their spatial configuration), and by taking a long-term approach. 相似文献
508.
农业循环经济的理论与实践 总被引:12,自引:1,他引:12
李克国 《中国环境管理干部学院学报》2005,15(1):11-13,21
发展农业循环经济是解决我国"三农"问题的有效途径.本文首先从农业可持续发展观的形成、农业循环经济的理论基础、农业循环经济的主要内容三方面对农业循环经济的基本理论进行论述.然后,对秦皇岛市农业生产存在的问题进行了分析.最后,提出了秦皇岛市发展农业循环经济的对策. 相似文献
509.
Christopher R. Blattel Karl W.J. Williard Sara G. Baer James J. Zaczek 《Journal of the American Water Resources Association》2005,41(2):301-307
ABSTRACT: Forest and grass riparian buffers have been shown to be effective best management practices for controlling nonpoint source pollution. However, little research has been conducted on giant cane [Arundinaria gigantea (Walt. Muhl.)], a formerly common bamboo species, native to the lower midwestern and southeastern United States, and its ability to reduce nutrient loads to streams. From May 2002 through May 2003, orthophosphate or dissolved reactive phosphate (DRP) concentrations in ground water were measured at successive distances from the field edge through 12 m of riparian buffers of both giant cane and mixed hardwood forest along three streams draining agricultural land in the Cache River watershed in southern Illinois. Giant cane and mixed hardwood forest did not differ in their DRP sequestration abilities. Ground water DRP concentrations were significantly reduced (14 percent) in the first 1.5 m of the buffers, and there was an overall 28 percent reduction in DRP concentration by 12 m from the field edge. The relatively low DRP reductions compared to other studies could be attributed to high DRP input levels, narrow (12 m) buffer lengths, and/or mature (28 to 48 year old) riparian vegetation. 相似文献
510.
Allah Bakhsh Ramesh S. Kanwar 《Journal of the American Water Resources Association》2005,41(2):333-341
ABSTRACT: Grouping of nitrate‐nitrogen (NO3‐N) leaching losses from agricultural fields into spatial clusters can help determine the cause/effect relationships for their occurrence. This study was designed to investigate the spatial relationships of low, medium, and high NO3‐N leaching losses clusters with soil and landscape attributes using cluster and discriminant analysis and the map overlay capability of a geographical information system (GIS). Field measured data of a six‐year (1993 through 1998) study on NO3‐N leaching losses from 36 experimental fields at the Iowa State University's northeastern research center near Nashua, Iowa, were normalized on an annual basis to compare over the years. The cluster analysis resulted in the formation of three clusters based on the satisfactory evaluation criteria of pseudo‐F statistic, cubic clustering criterion, and R2 values. The discriminant analysis, carried out on the basis of clusters, identified elevation and subsurface drainage as the factors that contributed significantly (p > 0.01) in discriminating among these clusters. The verification of discriminant functions developed on these factors predicted the cluster membership for all the groups with an overall accuracy of 86 percent. The map overlay analyses of GIS showed that spatial occurrence of the clusters transporting high NO3‐N leaching losses was affected by the interaction of soil type and elevation levels. 相似文献