共查询到20条相似文献，搜索用时 31 毫秒
1.
A previous analysis had assumed that about 20% of 1990 U.S. C emissions could be avoided by the substitution of biomass energy technologies for fossil energy technologies at some point in the future. Short-rotation woody crop (SRWC) plantations were found to be the dedicated feedstock supply system (DFSS) offering the greatest C emission reduction potential. High efficiency biomass to electricity systems were found to be the conversion technology offering the greatest C emission reduction potential. This paper evaluates what would be required in terms of rate of technology implementation and time period to reach the 20% reduction goal. On the feedstock supply side, new plantings would have to installed at an average a rate of 1×106 ha yr?1 while average yields would have to increase by 1.5% annually over the 35-year period. Such yield increases have been observed for high value agricultural crops with large government research support. On the generation side, it requires immediate adoption of available technologies with a net efficiency of 33% or higher (such as the Whole Tree EnergyTMtechnology), installation of approximately 5000 MWe of new capacity each year, and rapid development and deployment of much higher efficiency technologies to result in an average of 42% efficiency by 2030. If these technology changes could be achieved at a linear rate, U.S. C emission reduction could progress at a rate of about 0.6 % yr?1 over the next 35 years. 相似文献
2.
3.
《Communications in Soil Science and Plant Analysis》2012,43(9-10):811-830
Abstract A survey was conducted of 55 state and 371 commercial laboratories throughout the United States in order to document the current applications of plant analyses and the extent of application of the diagnosis and recommendation integrated system (DRIS) and to identify factors that have hindered or facilitated the implementation of the DRIS. State labs listed “research”; and commercial labs listed “diagnosis of nutrient deficiencies”; as the most common uses for plant analyses. Plant analysis results were widely used in combination with soil tests when diagnosing nutrient deficiencies and recommending corrective action (96% of state labs and 92% of commercial labs diagnosing nutrient deficiencies). Nationwide, the sufficiency range was the most commonly identified method of interpreting plant analyses (61% of the state and 58% of the commercial labs). The DRIS was used more extensively in the North Central region (14 labs) than in any other region. The two most commonly identified factors hindering the implementation of the DRIS were 1) lack of field verification and/or calibration and correlation data and, 2) unfamiliarity with the system. Computer availability appears to be the most important factor facilitating the implementation of the DRIS. 相似文献
4.
Land shortages are forcing more smallholder farmers to cultivate tropical steeplands. Resulting accelerated soil erosion is being countered by the promotion of soil conservation (SC) technologies, such as cross‐slope barriers, which aim to reduce soil loss and preserve land productivity. However, farmer adoption rates tend to be low. This is often attributed to the farmers' conservatism or lack of education. Research in Honduras's steeplands demonstrates that farmers value SC, provided that it promotes agricultural production. Field research from 1995–98, involving farmed test plots on slopes greater than 35 per cent (19 degrees), demonstrates that at least one typical SC technology—live barriers of Vetiveria zizanioides (vetiver grass)—has little or no impact on maize yield. This means that farmers see little benefit from their investment in the SC method. They find that erratic rainfall, pests and diseases and a lack of economic resources are far greater threats to their livelihoods than soil erosion. Consequently, SC has a low priority. Keeping soil in place avoids major off‐farm disbenefits. However, the SC technique tested here made no discernible difference to slope foot sediment yields during the life of this study. In sum, a new approach is needed. Promoting ‘Better Land Husbandry’ strategies, which seek to combine farmers' concerns about productivity with conservationists' concerns about reducing soil erosion—often via cover‐management—seem to be the best way forward. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
5.
6.
Most desertification research focuses on degradation assessments without putting sufficient emphasis on prevention and mitigation strategies, although the concept of sustainable land management (SLM) is increasingly being acknowledged. A variety of already applied conservation measures exist at the local level, but they are not adequately recognised, evaluated and shared, either by land users, technicians, researchers, or policy makers. Likewise, collaboration between research and implementation is often insufficient. The aim of this paper is to present a new methodology for a participatory process of appraising and selecting desertification mitigation strategies, and to present first experiences from its application in the EU‐funded DESIRE project. The methodology combines a collective learning and decision approach with the use of evaluated global best practices. In three parts, it moves through a concise process, starting with identifying land degradation and locally applied solutions in a stakeholder workshop, leading to assessing local solutions with a standardised evaluation tool, and ending with jointly selecting promising strategies for implementation with the help of a decision support tool. The methodology is currently being applied in 16 study sites. Preliminary analysis from the application of the first part of the methodology shows that the initial stakeholder workshop results in a good basis for stakeholder cooperation, and in promising land conservation practices for further assessment. Study site research teams appreciated the valuable results, as burning issues and promising options emerged from joint reflection. The methodology is suitable to initiate mutual learning among different stakeholder groups and to integrate local and scientific knowledge. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
7.
分析了数据中心机房主要耗能构成,得出要打造绿色节能机房必须降低机房的能源消耗大户空调和IT设备的能源消耗。在扬州市政府数据中心设计和实施建设过程中,针对机房制冷排热和IT设备选型部署,采取了多种绿色节能措施和手段。在降低机房制冷能耗方面,提出采用精确送风的封闭热通道技术将机房内冷、热气流分离,使热空气不在机房停留。同时,在空调外机加装雾化喷淋技术来降低空调能源消耗。在服务器选型及部署上,采用高性能、低功耗的服务器并运用虚拟化和云计算技术打造了一个绿色节能的数据中心机房。 相似文献
8.
Ribeiro Hugo da Silva Joana Gomes Jesus João Magalhães Catarina Dias Joana M. Danko Anthony S. 《Journal of Soils and Sediments》2019,19(1):439-450
Purpose
Biodiesel is a renewable fuel that can be mixed with toluene and be accidentally released into anoxic ecosystems and impact soil microbial communities. Therefore, the aim of the present work was to examine, under nitrate-reduction conditions, the biodegradation of toluene in the presence of two different types of biodiesel (sunflower and rapeseed), and their impact on the bacterial community structure.
Materials and methodsSediment samples were spiked individually with toluene, biodiesel, and their blends in laboratory-designed microcosms. Sunflower oil biodiesel was produced in the laboratory, while rapeseed oil biodiesel was a commercial product. Degradation of biodiesels and blends was monitored by directly measuring the substrate or indirectly by determining nitrate removal during the course of the experiment. Denitrification rates were estimated with the acetylene inhibition technique. Denaturing gradient gel electrophoresis was used to assess impacts on the bacterial community structure exposed to biodiesels, blends, and toluene.
Results and discussionThe results of this study showed that toluene and biodiesel were completely degraded within 10 days. Biodiesel significantly affected the bacterial community structure at a similar magnitude, independently of its origin. Additionally, toluene impacted the bacterial community and denitrification process to a lower extent than biodiesel and a clear decrease in the relative bacterial richness and diversity was shown in samples with biodiesel and blends. To the best of our knowledge, this is one of the first reports describing degradation of biodiesel alone and blends under nitrate-reducing conditions, and also the effects of these compounds on the denitrification process. In addition, due to the recently discovered “oxygenic denitrification” process, the acetylene inhibition technique and nitrous oxide quantification may not be the most adequate tool to estimate denitrification rates. Further detailed studies are advised to understand whether the identified bacterial community shift impacts ecosystem functions.
ConclusionsOur results help to understand the biodegradation of toluene, biodiesel, and their blends in sediments under nitrate-reducing conditions and might be important in implementing bioremediation strategies in anoxic environments.
相似文献9.
Gianni Andreottola Luca Bonomo Giorgia De Gioannis Elisa Ferrarese Aldo Muntoni Alessandra Polettini Raffaella Pomi Sabrina Saponaro 《Journal of Soils and Sediments》2010,10(1):142-150
Purpose
The fairly high amounts of sediments dredged in coastal or internal water bodies for navigational and/or environmental purposes claims for the identification of appropriate management strategies. Dredged sediments are frequently affected by organic and inorganic contamination, so that their reuse, as an alternative to final landfill disposal, could need remediation. In this framework, a two-year joint research project was carried out to assess the feasibility of different remediation technologies for the treatment of polluted sediments. 相似文献10.
Robert S. Allen 《Journal Of Agricultural & Food Information》2013,14(4):35-47
ABSTRACT This paper analyzes the agricultural research output on energy crops and bioenergy for the period 2000–2005. Seven hundred eighty-three (783) articles gathered from CAB Abstracts from this period were analyzed to determine which disciplines have been publishing the most on this subject. The findings show that engineering-related research is most prevalent but that twelve distinct agricultural disciplines produced research on the subject during the study period, with varying degrees of productivity for each discipline. The actual agricultural energy resources being researched were determined by examining the 783 articles. The resources were divided into woody crops, non-woody crops, and animal-based resources, and the number of articles for each was tabulated. The three resource types were further examined to create a list of the individual crops or animal-based resources under investigation, along with the number of articles for each individual crop or resource. The core journal literature dealing with energy crops and bioenergy was determined by doing searches in both CAB Abstracts and Web of Science and tabulating the number of articles appearing in each journal. This allowed for the creation of a core journal list, ranked by the number of appropriate articles appearing in each journal. 相似文献
11.
《Communications in Soil Science and Plant Analysis》2012,43(4):259-265
Abstract Results of a field experiment, comprising elemental S and three commercial preparations of Fe, applied with and without several other factors showed that the application of S was significantly better than that of Fe supplying materials in preventing the incipient chlorosis of corn leaves on the alkaline calcareous soils. Prevention of chlorosis in corn due to sulphur application increased the grain yield of corn 25–31%. Leaf samples from plants raised with Fe supplying materials were chlorotic even though they contained significantly higher amounts of Fe. Persistence of chlorosis in spite of high Fe content of leaves, vis a vis freedom from chlorosis in spite of low Fe content, suggest that deficiency of Fe was not a factor in chlorosis. Freedom from chlorosis accompanied by significant increases in corn yields due to S application, on the contrary, show that it was the lack of S rather than Fe as the cause of Chlorosis. When the supply of S is low, Fe seems to be subjected to a great deal of chemical inactivation and under conditions of stress more and more absorption of Fe is necessitated. In all probability the rate of inactivation exceeds the rate of absorption and chlorosis develops. In this situation either the plant's ability to utilize iron is affected or the physiological availability of absorbed iron is very low. Increased S seems to arrest the process of Fe inactivation by providing a better nutritional environment. 相似文献
12.
《国际水土保持研究(英文)》2014,2(4):1-12
Conservation agriculture (CA) technologies involve minimum soil disturbance, permanent soil cover through crop residues or cover crops, and crop rotations for achieving higher productivity. In India, efforts to develop, refine and disseminate conservation-based agricultural technologies have been underway for nearly two decades and made significant progress since then even though there are several constraints that affect adoption of CA. Particularly, tremendous efforts have been made on no-till in wheat under a rice-wheat rotation in the Indo-Gangetic plains. There are more payoffs than tradeoffs for adoption of CA but the equilibrium among the two was understood by both adopters and promoters. The technologies of CA provide opportunities to reduce the cost of production, save water and nutrients, increase yields, increase crop diversification, improve efficient use of resources, and benefit the environment. However, there are still constraints for promotion of CA technologies, such as lack of appropriate seeders especially for small and medium scale farmers, competition of crop residues between CA use and livestock feeding, burning of crop residues, availability of skilled and scientific manpower and overcoming the bias or mindset about tillage. The need to develop the policy frame and strategies is urgent to promote CA in the region. This article reviews the emerging concerns due to continuous adoption of conventional agriculture systems, and analyses the constraints, prospects, policy issues and research needs for conservation agriculture in India. 相似文献
13.
Phytoremediation Technology: Hyper-accumulation Metals in Plants 总被引：2，自引：0，他引：2
This paper reviews key aspects of phytoremediation technology and the biological mechanisms underlying phytoremediation. Current knowledge regarding the application of phytoremediation in alleviating heavy metal toxicity is summarized highlighting the relative merits of different options. The results reveal a cutting edge application of emerging strategies and technologies to problems of heavy metals in soil. Progress in phytoremediation is hindered by a lack of understanding of complex interactions in the rhizosphere and plant based interactions which allow metal translocation and accumulation in plants. The evolution of physiological and molecular mechanisms of phytoremediation, together with recently-developed biological and engineering strategies, has helped to improve the performance of both heavy metal phytoextraction and phytostabilization. The results reveal that phytoremediation includes a variety of remediation techniques which include many treatment strategies leading to contaminant degradation, removal (through accumulation or dissipation), or immobilization. For each of these processes, we review what is known for metal pollutants, gaps in knowledge, and the practical implications for phytoremediation strategies. 相似文献
14.
ABSTRACT The concern about global climate change continues to increase research interest regarding carbon and nitrogen dynamics in the soil. This is based on their role in maintaining soil fertility, which can instead be a source of greenhouse gas emissions if not managed properly, while threatening food security. Humid tropical conditions enable intensive agricultural cultivation with various cropping systems to fulfill the demand for agriculture products. Such climate accelerates the soil organic matter decomposition rate so that it strongly influences soil carbon and nitrogen dynamics. However, inappropriate implementation of intensive agricultural systems that does not consider the balance between carbon and nitrogen input and output, negatively affects soil fertility, mainly decreasing soil organic carbon and total soil nitrogen, changing the composition of carbon and nitrogen owing to the loss of soil organic matter through erosion and leaching, thus, causing soil degradation. Mitigation strategies can be performed by using organic matter and crop residue, crop rotation and improvement of crop pattern, soil tillage and fertilization, cover crops and mulch. Sustainable land management for maintenance of soil organic carbon and total soil nitrogen dynamics should be locally and globally developed and adopted for a more sustainable agricultural system. Recovery of soil capacity to accumulate carbon is a strategic step to reduce the impact of climate change. Hence, an intensive study on efficient soil organic carbon management is required to improve food production and mitigation of climate change to attain sustainable development goals in 2030. 相似文献
15.
The "oxygen paradox" of dinitrogen-fixing bacteria 总被引：6，自引：0，他引：6
N2 fixation by aerobic bacteria is a very energy demanding process, requiring efficient oxidative phosphorylation, while O2 is toxic for the nitrogenase complex. N2-fixing bacteria have evolved a variety of strategies to cope with this apparent "O2 paradox". This review compares strategies that azospirilla and other well-known N2-fixing soil bacteria use to overcome this O2 paradox. Attention will be given to the relationships between the natural habitat of these soil bacteria and their prevailing adaptations. In view of this knowledge the following questions will be addressed: are the specific adaptations observed in azospirilla sufficient to allow optimal proliferation and N2 fixation in their natural habitat? Could improving the O2 tolerance of the N2-fixing process contribute to the development of more efficient strains for the inoculation of plants? 相似文献
16.
《Communications in Soil Science and Plant Analysis》2012,43(5):435-449
Abstract Literature dealing with general properties of soil K and with K relationships in Atlantic Coastal Plain Soils was discussed. Potassium, among major and secondary nutrient elements, is the most abundant in soils. It, among mineral cations required by plants, is largest in non‐hydrated size. Potassium has a polarizability equal to .88 Å3 and a low hydration energy of 34 kcal g?1 ion?1. The major K forms in soils are water soluble, exchangeable, nonexchangeable, and mineral. Various dynamic interrelationships exist between these forms with the reaction kinetics between the various phases determining the fate of applied K. Many Atlantic Coastal Plain soils contain high levels of total K. Most of the total K in these soils is contained in mineral forms such as micas and K‐feldspars. These K forms are slowly released to solution and exchangeable forms that are available to plants. Many researchers have noted a lack of crop response to K fertilization on Atlantic Coastal Plain soils. This lack of response has been ascribed to the high indigenous levels of mineral and non‐exchangeable K in the soils which would become available to crops. Some researchers have also attributed the lack of response to K accumulations in subsoil from leaching of applied K. If the physical and chemical conditions were favorable in the subsoil horizons, e. g., no pan formation and no severe Al toxicity, plant roots could absorb K from the subsoil horizons. 相似文献
17.
J. Y. Wang 《Water, air, and soil pollution》1979,12(1):83-90
In the context of a broad definition of agrochemistry, any chemicals produced by agricultural activities may be included here. Interactions between agrochemicals and their environment are the central theme of this paper. This is elucidated in terms of the alterations of radiant energy transfer, heat budget, and water balance at the interface of air and ground. The disrupted states of the atmosphere are presented by climatic elements, weather phenomena, and edaphic conditions. Realizing that the whole earth-atmosphere system tends to approach a state of minimal free energy, a step by step combination of the physical and/or chemical process is given. Emphasis is on the visible and infrared radiant energy transfer, attenuation, nucleation, sorption-condensation, fermentation, combustion, and radiative heating processes. Although this paper stresses the micro-mesoscale weather phenomena and short term effects, agrochemical impact on long-term and global weather and climate should not be ignored. Due to lack of study in this subject area, recommendations for future research stress both experimental and mathematical modeling techniques. 相似文献
18.
基于层次分析法和模糊综合评价的沼气工程技术筛选 总被引：6，自引：11，他引：6
不同沼气工程技术对地域自然条件、环境制约条件、原料种类等因素的适应性有较大差异,科学客观的沼气工程技术筛选方法,是保证沼气工程长期稳定发挥其最大能效的重要基础。该文提出了基于层次分析法(analytic hierarchy process,AHP)和模糊综合评价的沼气工程技术筛选方法和决策流程,构建了沼气工程技术筛选的指标体系;以领域专家实地调查结果为基础,通过AHP法获得沼气工程技术筛选不同指标的权重,然后采用模糊综合评价方法对沼气工程技术进行排序。利用该方法筛选的结果与武汉地区的实际运行效果一致。采用AHP和模糊综合评价方法相结合解决复杂的多因素决策问题,既能克服AHP指标不易量化的主观性,又能避免模糊综合评价方法对指标权重的忽视,可为沼气工程技术筛选提供科学方法。 相似文献
19.
? Environmental contamination by synthetic polynuclear aromatic hydrocarbons (PAHs) has become a major pollution problem. Plant tissues, lignin, soil humus constituents, some pesticides, and numerous commercial organic chemicals are also based upon aromatic building blocks. Many of these molecules are potentially toxic and carcinogenic. Some PAH compounds occur naturally at a low concentration in soils. Long exposure to naturally occurring hydrocarbons has enabled bacteria to evolve enzymes that degrade them.Landfarming and incineration are the primary technologies used for removing PAH compounds from soils and groundwater. Recent data suggest that bioremediation by PAH composting can offer significant advantages to other treatment alternatives. Landfarming is a relatively uncontrolled method of reducing PAHs in residues. Composting is quicker, more controlled, and requires less space than landfarming. Although composting is slower and less complete than incineration, it is significantly more cost-effective.This presentation deals with the feasibility of composting PAH contaminated soils and residues. Included will be methods for process evaluation and control, degradation potential of specific PAHs, and determining the application of composting to specific situations. 相似文献
20.
实现碳达峰、碳中和目标是我国经济社会深刻的系统性变革,“双碳”目标的提出将对我国土壤污染修复领域产生重要影响,并促进研发更多符合绿色可持续修复的新技术和新产品。为了解污染场地可持续修复领域的研究进展和发展动态,采用CiteSpace和VOSviewer科学图谱绘制软件对Web of Science数据库核心集中2000 ~ 2020年污染场地可持续修复领域的相关文献进行了计量分析,通过合作、共现和共被引等网络分析,探索该领域的研究热点和前沿趋势。结果表明:1）近年来世界范围内该领域发文数量总体呈增长趋势;2）该领域发文量前三的国家是美国、英国和中国;3）该领域的主要发文机构有清华大学、剑桥大学和中国科学院;4）Hou、Norrman和Rosen是该领域发文数量较多的研究人员;5）载文量较多的期刊有Science of the Total Environment、Journal of Environmental Management和Journal of Cleaner Production;6）目前污染场地多采用异位修复的方式修复,原位修复技术及各类耦合修复技术的研究将会增多;7）对土壤修复的可持续研究逐渐增多,地下水修复的可持续研究较少。制定科学合理的具有中国特色的污染场地可持续修复方法势在必行;降低污染修复全过程的环境影响和二次污染是响应碳减排号召的重要过程,环境友好型材料研发、绿色可持续修复技术的实施是污染场地可持续修复领域的重要措施。 相似文献