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1.
本文测定了成都市龙泉山缺铁失绿症果树埋植铁剂“颗颗灵”三年后叶片的叶绿素含量、厚度、100叶重、100叶体积、100叶面积等叶片生理和生长指标的变化。结果表明,树干深层埋植铁剂“颗颗灵”对供试桃、李、樱桃和柑桔树具有持续的后效.  相似文献   

2.
本文测定了成都市龙泉山缺铁失绿症果树埋植铁剂“颗颗灵”1年后叶片的叶绿素含量、厚度、100叶重、100叶体积、100叶面积等叶片生理和生长指标的变化。结果表明,树干层埋植铁剂“颗颗灵”对供试树、李、樱桃和柑桔树具有持续的后效。  相似文献   

3.
本文概述了植物的铁素营养、果材缺铁黄化病的诊断治疗方法,论述了高涌液注射法矫治果树缺铁黄化病的理论、假说、树木微型注射器、克黄灵高渗液、树干穴位注射法、树干穴位插管法及其应用前景。  相似文献   

4.
矫正果树缺铁症的简易方法:树干木质部埋植法   总被引:2,自引:2,他引:0  
童风  李翠兰 《资源开发与市场》1995,11(3):112-113,123
矫正果树缺铁症的简易方法──树干木质部埋植法童风,李翠兰,郎家文(四川省自然资源研究所,成都610015)我国各种果树的缺铁症状都十分突出,除常见于北方干旱、半干旱地区的石灰性土壤外,从京津地区向南延伸到江苏省北部,向西延伸到甘肃的兰州、青海的西宁都...  相似文献   

5.
“为绿而歌志岂休,不到天涯不回头,化作一枚橄榄叶,风雨人寰飘悠悠。”风雨飘摇,四海为家,我注定要失去些什么,但注定也会得到些什么。于得于失,我看得都不是太重,我所看重的所追求的就是生命达到完美、理想达到真实的这个过程。也许我会在这个过程中倒下,就像一片绿叶从树上掉落一样。但我无悔,因为我毕竟绿过,为了我热爱且珍惜的生命,为了这美丽但已残破的地球。——叶榄  相似文献   

6.
果树中许多栽培品种是由野生果树驯化、选种和培育而来。中国是世界上最重要的果树起源中心之一 ,现在世界各国栽培的很多品种如梨、桃、杏、柿、枣、猕猴桃、枇杷、龙眼和荔枝等均起源于中国。中国还蕴藏着极其丰富的野生果树资源尚未进行充分开发利用 ,因此对其开发利用迫在眉睫。我国野生果树资源极为丰富 ,共有野生、半野生果树 10 76种 ,占果树总量的 84 85 %。野生果树除直接提供可食果品和食品加工原料外 ,许多还是栽培果树的优良砧木及重要的蜜源、药用、香料来源。随着新一轮果树资源开发的不断深入 ,野生果树以其庞大的数量、广泛…  相似文献   

7.
袋装控释铁肥压根法矫治桃树黄叶病的效果   总被引:1,自引:1,他引:0  
本文介绍了袋装控释铁肥压根法矫治桃树缺铁黄叶病的效果。该法具有大幅度增加叶绿素含量.提高果实产量,改善果实品质,降低矫治成本,安全可靠,效果好的特点。  相似文献   

8.
广西壮族自治区环江县选择果树业作为科技扶贫的支柱产业是近几年来探索出来的一条成功经验。通过对环江县科环公司果树业发展模式的分析,作者对桂西北果树业的结构优化及产业化道路进行了探讨。  相似文献   

9.
<正>"绿了花乡,绿了沭阳,绿了虞美人生长的地方;绿了白杨路,绿了芦荡,绿了芳草地环绕的地方;绿绿的一支歌我们大家唱,绿绿的收获里有金色的希望,绿绿的城市充满激情,绿色的大树是最美的塑像……"这是由任红举作词、孟庆云作曲、张也演唱的江苏省沭阳县形象歌曲《绿满花乡》。那甜美的歌声,动人的旋  相似文献   

10.
广西壮族自治区环江县选择果树业作为科技扶贫的支持产业是近几年来探索出来的一条成功经验,通过对环江县科技公司果树业发展模式的分析,作者对西北果树业的结构优化及产业化道路进行了探讨。  相似文献   

11.
以协商的方式确定水污染物间接排放标准的规定打破了人们对标准确定性、强制性的传统认识。协定标准的优势在于充分利用污水处理厂的污水处理能力,减轻企业的污水处理负担,使企业可以集中力量搞生产。协定标准具有灵活性和优越性,应充分利用。通过对协定标准概念和重要性的分析,指出协定标准存在效力不确定、缺少对协定范围的限制等问题,造成协定标准在实践中通常被忽视或者滥用。并从明确协定标准的范围、加强排污企业的管理和协定标准的监督等方面,进一步提出了限制和完善水污染物间接排放标准的建议。  相似文献   

12.
The functions of packaging are derived from product requirements, thus for insight into the environmental effects of packaging the actual combination of product and package has to be evaluated along the production and distribution system. This extension to all related environmental aspects adds realism to the environmental analysis and provides guidance for design while preventing a too detailed investigation of parts of the production system. This approach is contrary to current environmental studies where packaging is always treated as an independent object, neglecting the more important environmental effects of the product that are influenced by packaging. The general analysis and quantification stages for this approach are described, and the currently available methods for the assessment of environmental effects are reviewed. To limit the workload involved in an environmental assessment, a step-by-step analysis and the use of feedback is recommended. First the dominant environmental effects of a particular product and its production and distribution are estimated. Then, on the basis of these preliminary results, the appropriate system boundaries are chosen and the need for further or more detailed environmental analysis is determined. For typical food and drink applications, the effect of different system boundaries on the outcome of environmental assessments and the advantage of the step-by-step analysis of the food supply system is shown. It appears that, depending on the consumer group, different advice for reduction of environmental effects has to be given. Furthermore, because of interrelated environmental effects of the food supply system, the continuing quest for more detailed and accurate analysis of the package components is not necessary for improved management of the environmental effects of packaging.  相似文献   

13.
ABSTRACT: The geochemistry and nature of the flow of ground water not only control the supply potential but constitute clues to the whole geology of an area. A study has been made of the largest available assemblage of data from 161 wells for the Island of Montreal collected by the Geological Survey of Canada in 1951–53. Data indicated that the system is generally subartesian, flowing from the principal topographically high areas towards the shores of the Island. As the probable use is about 13% of the estimated recharge of 140 million liters per day, most wells could be supplied by local recharge. The study has confirmed the predominance of calcium bicarbonate ground water from the carbonate sequence. The waters appeared to be saturated with respect to CaCO3 in all but 10 wells. The presence of other types of waters suggests the effects of the igneous intrusions of the area, the post-glacial marine submergence and the upward movement of waters from deep sources through fault and other structural zones. Confirmation of the significant variations in chemical composition in some neighboring wells indicated the future need for repetitive sampling from specific horizons for chemical and isotopic analyses.  相似文献   

14.
ABSTRACT: Winterkill, the death of fish under ice due to oxygen deficiency, threatens hundreds of shallow lakes in the upper Midwest of the United States every winter. For decades, attempts have been made to prevent winterkill, usually through aeration, with mixed results. In large part, the failure of strategies to prevent winterkill can be linked to a lack of understanding of winter limnology and in particular, of oxygen dynamics under ice. Most winterkill lakes behave as closed systems with regard to oxygen. Consequently, the oxygen content of an ice and snow covered lake is essentially a function of the amount of initial storage and the rate of depletion. Should the stored oxygen be insufficient to prevent near anoxia before melting of the ice cover occurs, winterkill will result. Most oxygen consumption in ice covered lakes is due to bacterial respiration and chemical oxidation at the sediment/water interface, the remainder occurring in the water column. Oxygen consumption (and thus depletion) is a function of the velocity and oxygen concentration of the near sediment water. This is due to the fact that oxygen transport to the sediment is mediated by a diffusive boundary layer adjacent to the sediment surface. Winter oxygen depletion rates decrease when the oxygen concentration of the overlying water falls below about 3 mg/l. Aeration techniques which increase the oxygen concentration and velocity of the near-sediment water also increase the oxygen consumption (depletion) rate.  相似文献   

15.
The key issue in achieving a high extent of biodegradation of beet molasses vinasse is to establish the conditions for the assimilation of betaine, which is the main pollutant in this high-strength industrial effluent. In the present study, aerobic batch biodegradation was conducted over the temperature range of 27-63°C (step 9°C), at a pH of 6.5 and 8.0, using a mixed culture of bacteria of the genus Bacillus. Betaine was assimilated at 27-54°C and the pH of 8.0, as well as at 27-45°C and the pH of 6.5. The processes where betaine was assimilated produced a high BOD(5) removal, which exceeded 99.40% over the temperature range of 27-45°C at the pH of 8.0, as well as at 27°C and the pH of 6.5. Maximal COD removal (88.73%) was attained at 36°C and the pH of 6.5. The results indicate that the process can be applied on an industrial scale as the first step in the treatment of beet molasses vinasse.  相似文献   

16.
It is increasingly clear that a wide range of stakeholders should be included in the problem formulation phase of research aimed at solving environmental problems; indeed the inclusion of stakeholders at this stage has been formalized as an integral part of ecological risk assessment. In this paper, we advocate the additional inclusion of stakeholders in the refinement of research methods and protocols and in the execution of the research, rather than just at the final communication and reporting phase. We use a large study of potential radionuclide levels in marine biota around Amchitka Island as a case study. Amchitka Island, in the Aleutian Island Chain of Alaska, was the site of three underground nuclear tests (1965-1971). The overall objective of the biological component of the study was to collect a range of marine biota for radionuclide analysis that could provide data for assessing current food safety and provide a baseline for developing a plan to monitor human and ecosystem health in perpetuity. Stakeholders, including regulators (State of Alaska), resource trustees (US Fish and Wildlife Service, State of Alaska), representatives of the Aleut and Pribilof Island communities, the Department of Energy (DOE), and others, were essential for plan development. While these stakeholders were included in the initial problem formulation and approved science plan, we also included them in the refinement of protocols, selection of bioindicators, selection of a reference site, choice of methods of collection, and in the execution of the study itself. Meetings with stakeholders resulted in adding (or deleting) bioindicator species and tissues, prioritizing target species, refining sampling methods, and recruiting collection personnel. Some species were added because they were important subsistence foods for the Aleuts, and others were added because they were ecological equivalents to replace species deleted because of low population numbers. Two major refinements that changed the research thrust were (1) the inclusion of Aleut hunters and fishers on the biological expedition itself to ensure that subsistence foods and methods were represented, and (2) the addition of a fisheries biologist on a NOAA research trawler to allow sampling of commercial fishes. Although the original research design called for the collection of biota by Aleut subsistence fishermen, and by a commercial fishing boat, the research was modified with continued stakeholder input to actually include Aleuts and a fisheries biologist on the expeditions to ensure their representation. The inclusion of stakeholders during the development of protocols and the research itself improved the overall quality of the investigation, while making it more relevant to the interested and affected parties. Final responsibility for the design and execution of the research and radionuclide analysis rested with the researchers, but the process of stakeholder inclusion made the research more valuable as a source of credible information and for public policy decisions.  相似文献   

17.
Histopathological and histochemical variations in non-specific esterases of the intestinal epithelial lining of the earthworm (Pheretima elongata), exposed to a single field dose of the herbicide glyphosate, were studied on the first, second, third, and fourth week of exposure. A severe cell death was observed in the intestine during the first and second weeks of exposure and mortality exceeded 50 percent. In the third week of exposure, the cells of the intestinal lining of the worms which had survived started regenerating and in the fourth week of exposure the epithelial lining regained its original characteristics and architecture, suggesting the high regenerative power of earthworms. Non-specific esterases showed an intense activity in the first week of the exposure and then decreased in the second week to nearly a minimum, where the entire cell structure was lost. However, the activity of the enzyme remained low until the third week where there was a small rise in the activity, and was confined to certain places in the cytoplasm. In the fourth week, almost a complete regeneration of the epithelial lining as well as the non-specific esterases activity was observed and became quite similar to that of the control worms. These results suggest that glyphosate, even at the recommended field dose, could cause cell death and interfere with non-specific esterases activity of the epithelial lining of the intestine of P. elongata causing at least 50 percent mortality in the population of the worms.  相似文献   

18.
沿海油田污染物入海通量及优化管理   总被引:3,自引:0,他引:3  
胜利油田所在的黄河三角洲诸条河流按入海类型分为三种形式:设有防潮闸的感潮河;设有排涝站的入海河;直流入海的感潮河。按照各河流入海段面、流速、流量和水体污染物浓度,建立起各种感潮河污染物入海通量模式,计算结果说明沿海油田排放的石油类污染物入海通量为1456t/a,COD入海量为5720t/a。根据各条入海河流不同功能和污染物入海量,按照国家地表水质标准,制定出入海河流环境组合目标,用总量控制方法提出污染源削减要求,以保证黄河三角洲沿海滩涂环境质量。并以污染物入海通量、河流径流量、污染物自净系数和污染物削减量等因子建立各条河流优化管理模型,为保护环境提供对策。  相似文献   

19.
底泥的氮、磷释放及其微生物影响的研究   总被引:2,自引:0,他引:2  
张恒军  吴群河 《环境技术》2003,41(Z1):20-23
氮和磷在自然界的循环已经引起了人们的关注,一方面因为氮和磷是生态系统中必不可少的营养元素,另一方面过剩的氮和磷会导致水域的富营养化 ,从而使生态平衡遭受破坏.本文综述了水体沉积物中氮和磷受微生物作用进行释放的影响,以及国内外的研究历史和现状.总结了氮磷微生物代谢的特点,并阐述了与传统认识相区别的最新发现和思想.本文试图从理论上说明微生物的氮磷释放机理,通过生物化学和分子动力的角度解释了细菌对氮磷的吸收和释放,即质子动势理论和Pho调控理论.目前,这一领域研究的热点是为了特殊的使用用途对于高效微生物的分离鉴别和组合培养,和对氮磷代谢的影响因素.  相似文献   

20.
Brown, Juliane B., Lori A. Sprague, and Jean A. Dupree, 2011. Nutrient Sources and Transport in the Missouri River Basin, With Emphasis on the Effects of Irrigation and Reservoirs. Journal of the American Water Resources Association (JAWRA) 47(5):1034‐1060. DOI: 10.1111/j.1752‐1688.2011.00584.x Abstract: SPAtially Referenced Regressions On Watershed attributes (SPARROW) models were used to relate instream nutrient loads to sources and factors influencing the transport of nutrients in the Missouri River Basin. Agricultural inputs from fertilizer and manure were the largest nutrient sources throughout a large part of the basin, although atmospheric and urban inputs were important sources in some areas. Sediment mobilized from stream channels was a source of phosphorus in medium and larger streams. Irrigation on agricultural land was estimated to decrease the nitrogen load reaching the Mississippi River by as much as 17%, likely as a result of increased anoxia and denitrification in the soil zone. Approximately 16% of the nitrogen load and 33% of the phosphorus load that would have otherwise reached the Mississippi River was retained in reservoirs and lakes throughout the basin. Nearly half of the total attenuation occurred in the eight largest water bodies. Unlike the other major tributary basins, nearly the entire instream nutrient load leaving the outlet of the Platte and Kansas River subbasins reached the Mississippi River. Most of the larger reservoirs and lakes in the Platte River subbasin are upstream of the major sources, whereas in the Kansas River subbasin, most of the source inputs are in the southeast part of the subbasin where characteristics of the area and proximity to the Missouri River facilitate delivery of nutrients to the Mississippi River.  相似文献   

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