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1.
The Environmental benefits and costs of conservation tillage 总被引:1,自引:0,他引:1
Every production practice, including conservation tillage, has positive or negative environmental consequences that may involve
air, land, water, and/or the health and ecological status of wildlife. The negative impacts associated with agricultural production,
and the use of conventional tillage systems in particular, include soil erosion, energy use, leaching and runoff of agricultural
chemicals, and carbon emissions. Several of these impacts are quantified. The conclusions suggest that the use of conservation
tillage does result in less of an adverse impact on the environment from agricultural production than does conventional tillage
by reducing surface water runoff and wind erosion. Additionally, wildlife habitat will be enhanced to some extent with the
adoption of conservation tillage and the benefits to be gained from carbon sequestration will depend on the soil remaining
undisturbed. Finally, further expansion of conservation tillage on highly erodible land will unquestionably result in an increase
in social benefits, but the expected gains will be modest. 相似文献
2.
Conservation tillage and input use 总被引:1,自引:0,他引:1
N. D. Uri 《Environmental Geology》1997,29(3-4):188-201
There continues to be a question as to the overall effectiveness of conservation tillage practices in reducing the impact
of agricultural production on the environment. While it is generally recognized that water runoff and soil erosion will decline
further, as tillage and mulch tillage systems are not used more extensively on cropland, what will happen to pesticide and
fertilizer use remains uncertain. To gain some insight into this, the conservation tillage adoption decision is modelled.
On the assumption that the decision to adopt conservation tillage is a two-step procedure, the first decision is whether or
not to adopt a conservation tillage production system and the second concerns the extent to which conservation tillage should
be used – appropriate models of the Cragg and Heckman (dominance) type are estimated. Based on farm-level data on corn production
in the United States for 1987, the profile of a farm on which conservation tillage was adopted is that the cropland had above-average
slope and experienced above-average rainfall, the farm was a cash grain enterprise, and it had an above-average expenditure
on pesticides and a below-average expenditure on fuel and custom pesticide applications. Additionally, for a farm adopting
a no-tillage production practice, an above-average expenditure was made on fertilizer.
Received: 18 September 1995 · Accepted: 6 December 1995 相似文献
3.
N. D. Uri 《Environmental Geology》1999,37(1-2):9-18
The impact of energy on the adoption of conservation tillage is of special importance in addressing concerns about the effect
of agricultural production on the environment in the United States. It is the subject of this paper. After establishing that
a relationship exists between the price of energy and the adoption of conservation tillage via cointegration techniques, the
relationship is quantified. It is shown that while the real price of crude oil, the proxy used for the price of energy, does
not affect the rate of adoption of conservation tillage, it does impact the extent to which it is used. Finally, there is
no structural instability in the relationship between the relative use of conservation tillage and the real price of crude
oil over the period 1963–1997.
Received: 6 February 1998 · Accepted: 4 May 1998 相似文献
4.
In the present investigation, an effort has been made to identify the critical sub-watersheds for the development of best
management plan for a small watershed of Eastern India using a hydrological model, namely, AVSWAT2000. A total of 180 combinations
of various management treatments including crops (rice, maize ground nut and soybean), tillage (zero, conservation, field
cultivator, mould board plough and conventional practices) and fertilizer levels (existing half of recommended and recommended)
have been evaluated. The investigation reveled that rice cannot be replaced by other crops such as groundnut, maize, mungbean,
sorghum and soybean since comparatively these crops resulted in higher sediment yield. The tillage practices with disk plough
have been found to have more impact on sediment yield and nutrient losses than conventional tillage practices for the existing
level of fertilizer. Sediment yield decreased in the case of zero tillage, conservation tillage, field cultivator, moldboard
plough, and conservation tillage as compare to conventional tillage. Lowest NO3–N loss was observed in zero tillage in all the fertilizer treatments, whereas field cultivator, moldboard plough and disk
plough resulted in increase of NO3–N loss. As compared to conventional tillage, the losses of soluble phosphorus were increased in moldboard plough. The losses
of organic nitrogen were also increased as fertilizer dose increased. After zero tillage the conservation tillage preformed
better in all the fertilizer treatments as per loss of organic nitrogen and organic phosphorus is concerned. It can be concluded
that the sediment yield was found to be the highest in the case of disk plough followed by moldboard plough, field cultivator,
conventional tillage, field cultivator and least in zero tillage practices. The nutrient losses were found to be in different
order with tillage practices, resulted highest in disk plough tillage practices. In view of sediment yield and nutrient losses,
the conservation tillage practice was found to be the best as the sediment yield is less than the average soil loss whereas
nutrient loss is within the permissible limit. 相似文献
5.
Transfrontier conservation has taken Southern Africa by storm, where the modus operandi remains simple and intuitive: by dissolving boundaries, local benefits grow as conservation and development spread regionally. However, in the case of South Africa’s section of the Great Limpopo Transfrontier Park, political and economic change redirects benefits to support ‘modern’ economies at the expense of rural livelihoods through community-based natural resources management (CBNRM). Neo-liberal agendas promoted by government and the transfrontier park derail efforts at decentralizing CBNRM initiatives beyond markets and state control. This paper argues that ‘hybrid neoliberal’ CBNRM has arisen in private and public sector delivery of devolved conservation and poverty relief projects as ‘tertiary production’ for regional development. As a result, ‘CBNRM’ projects related to and independent of transfrontier conservation support private sector interests rather than the resource base of rural livelihoods. Concluding sections assert that CBNRM can counter this neoliberal trend by supporting the land-based economy of local users living near the Great Limpopo Transfrontier Park. 相似文献
6.
An increasingly utilized strategy for expanding conservation in the developing world has been the promotion of protected areas
that supersede national borders. Alternatively known as transfrontier biosphere reserves, transfrontier or transboundary conservation
areas, or Peace Parks, these protected areas are aggressively advanced by conservation agencies for their purported ecological
and economic benefits. This article provides a comparative assessment of two case studies to understand the various impacts
of transboundary conservation. The Great Limpopo Transfrontier Park, which unites protected areas in South Africa, Mozambique
and Zimbabwe, is contrasted with efforts to protect jaguars along the United States–Mexico border. We argue that while these
cases are promising for the purposes of biodiversity protection, they demonstrate that transboundary conservation can minimize
political context, contributes to the hegemony of international conservation agendas, and remains closely linked to economic
neoliberalism and decentralization in the developing world.
相似文献
Brian KingEmail: |
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Noel D. Uri 《Environmental Geology》2000,40(1-2):41-52
Increase in the use of conservation practices by agriculture in the United States will enhance soil organic carbon and potentially
increase carbon sequestration. This, in turn, will decrease the net emission of carbon dioxide. A number of studies exist
that calibrate the contribution of various individual, site-specific conservation practices on changes in soil organic carbon.
There is a general absence, however, of a comprehensive effort to measure objectively the contribution of these practices
including conservation tillage, the Conservation Reserve Program, and conservation buffer strips to an change in soil organic
carbon. This paper fills that void. After recounting the evolution of the use of the various conservation practices, it is
estimated that organic carbon in the soil in 1998 in the United States attributable to these practices was about 12.2 million
metric tons. By 2008, there will be an increase of about 25%. Given that there is a significant potential for conservation
practices, which could lead to an increase in carbon sequestration, there are a number of policy options that can be pursued.
These include education and technical assistance, financial assistance, research and development, land retirement, and regulation
and taxes.
Received: 27 December 1999 · Accepted: 14 March 2000 相似文献
9.
生态功能优先背景下的西南岩溶区石漠化治理问题 总被引:12,自引:8,他引:4
文章分析了现有石漠化治理模式、物种选择、石漠化治理综合效益评估、消除贫困等方面存在的不足,并结合国家对西南岩溶石漠化区主体生态功能的定位,对未来石漠化治理过程中的几个关键问题进行了探讨,认为未来石漠化治理要更有效地兼顾生态与经济效益,提高生态补偿标准,完善生态补偿体制,促进石漠化区农村人口的城镇化转移,减少人口压力,消除农户破坏环境的驱动因素,促进石漠化治理成效的长期可持续发展,以保证西南岩溶石漠化区水土保持和生物多样性维护主体生态功能的实现。 相似文献
10.
屋顶花园是屋顶文化的延续和发展,是屋顶景观的再创造.它的营建可以为城市创造良好景观与环境,减少碳排放量、高效利用雨水、节约地下水,直接提高城市居民生活空间的舒适化和居住环境质量,而且合理的屋顶花园布局必然产生巨大的社会效益、经济效益和生态效益. 相似文献
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Modeling hydrological ecosystem services and tradeoffs: a case study in Baiyangdian watershed, China 总被引:2,自引:1,他引:1
Yang Bai Hua Zheng Zhiyun Ouyang Changwei Zhuang Bo Jiang 《Environmental Earth Sciences》2013,70(2):709-718
Policy makers and scientists consider that land use strategies are designed to provide direct benefits to people by protecting vital ecosystem services. However, due to lack of information and evaluation methods, there is no effective and systematic tool for assessing tradeoffs between direct human benefits and ecosystem services. Land use changes influence ecosystem properties, processes and components, which are the basis for providing services. Five alternative land use scenarios (no conversion of agricultural lands, no urban expansion, agricultural expansion, forestry expansion, and riparian reforestation) were modeled for the Baiyangdian watershed, China, a densely populated, highly modified watershed with serious water shortage and pollution problems. The model InVEST (Integrated Valuation of Ecosystem Services and Tradeoffs) is designed to inform decisions about natural resource management, with an aim to align economic forces with conservation. Three ecosystem services (agricultural production, hydropower production, and water quality) were modeled to balance direct benefits and hydrological ecosystem services using InVEST. The results showed that: hydropower production was the greatest in the forestry expansion, but the lowest in agricultural expansion; agricultural production was reduced the most in forestry expansion, while retained the most in riparian reforestation. Riparian reforestation also provided the highest N and P retention and lowest N and P exportation. Riparian reforestation was the optimal land use strategy, since it protected and enhanced the vital ecosystem services without undermining direct human benefits. This research presents an initial analytical framework for integrating direct human benefits and ecosystem services in policy planning and illustrates its application. Although there are important potential tradeoffs between ecosystem services, this systematic planning framework offers a means for identifying valuable synergies between conservation and development. 相似文献
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“生物可持续性”(bioSUSTAINABILITY)科学计划是生物多样性计划(DIVERSITAS)3个核心科学计划之一,是一个有关生物多样性的国际计划。bioSUSTAINABILITY有3个密切相关的研究焦点:①评价目前生物多样性保护和持续利用所采取的措施的有效性;②导致生物多样性丧失的社会、政治和经济驱动因子分析;③生物多样性保护与持续利用的社会选择和决策取向研究。介绍了bioSUSTAINABILITY的主要内容及其实施战略,并分析了它对保护和可持续利用生物多样性的重要作用。 相似文献
15.
ZhaoXun ZhaoTing 《《幕》》2003,26(4):302-309
Since 2000, based on a wealth of geological heritage sites and experience with their conservation, China has formally approved the establishment of forty four National Geoparks, whose distribution and characteristics are dominated by structural setting and neotectonism. Conserving and developing the sites have brought about favorable social, economic and environmental benefits, and created a positive climate for their inclusion in the worm Geopark network under the patronage of UNESCO. 相似文献
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民勤绿洲水资源利用的综合效益评价 总被引:2,自引:0,他引:2
水资源利用是民勤绿洲发展兴衰的关键影响因素. 将民勤绿洲水资源利用的历程划分为三个典型时期——"以粮为纲"时期、改革开放时期、生态保护时期, 并以其作为研究的特征时期, 建立了民勤绿洲水资源利用综合效益评价的数学模型. 利用网络层次分析法确定各项指标权重, 基于网络层次分析法的运算结果, 对民勤绿洲水资源利用的综合效益进行了定量评价, 结果表明: "以粮为纲"时期, 生态效益开始下降, 水资源利用的效果欠佳; 改革开放时期, 经济效益和社会效益均明显增长, 但生态效益出现新一轮下降, 水资源利用的效果有利有弊; 生态保护时期, 尤其是石羊河流域重点治理规划实施之后, 生态、经济和社会效益都开始上升, 水资源利用的效果相对最佳. 评价结果旨在为类似地区水资源利用政策措施的改进提供决策依据. 相似文献
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地质灾害防治工程可行性研究报告需要编写经济社会、环境效益综合评价。目前我国几百个泥石流防治工程及三峡水库区200多滑坡治理工程的可行性研究报告,均为定性的简单叙述,将灾害体危害范围内的承灾体价值总量作为经济效益,不能充分说明防治工程的重要性,提供了错误的决策依据。针对上述问题,文章研究了泥石流防治工程经济效益定量化评估模型和评估方法。为地质灾害设计单位使用,提高地质灾害防治工程可行性研究水平。泥石流防治中工种经济效益为投资者投入资金,灾害防治企业建设防治工程而减少承灾体的最大可能经济损失与投资者投入的资金之比。防治工程资金利税率=地质灾害最大可能经济损失-防治资金投入/防治资金收入;防治工程直接经济效益:最大可能经济损失-防治资金投入;投入产出比=防治资金投入:最大可能经济损失。泥石流防治工程经济效益评价方法第一步进行泥石流危害范围内的承灾体调查。第二步进行泥石流防治工程经济效益评价。其内容包括:防治工程概况;经济评价基本数据;经济效益计算;经济效益评价。该文以湖南省郴州市北湖区南溪泥石流为案例,进行了经济效益评价。 相似文献