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1.
阐述了生态农业的概念以及我国生态农业与国外生态农业的区别,指出生态农业理论指导体系、生态农业模式分类体系、生态农业技术体系、生态农业建设体系和生态农业保障体系是我国生态农业的重要组成部分. 相似文献
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我国生态农业发展现状与展望 总被引:8,自引:0,他引:8
阐述了生态农业的概念以及我国生态农业与国外生态农业的区别,指出生态农业理论指导体系、生态农业模式分类体系、生态农业技术体系、生态农业建设体系和生态农业保障体系是我国生态农业的重要组成部分。 相似文献
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发展生态农业的战略意义 总被引:2,自引:0,他引:2
石山 《中国生态农业学报》1999,7(4):1-4
分析了农业生态学定义和我国生态农业内涵之间的关系,系统阐述了农业生态学对生态农业建设类型分区、生态农业建设规划设计、生态农业模式建立和生态农业建设评价指标确定的指导意义,认为农业生态学是我国生态农业建设的理论基础,并通过生态农业建设实践促进了农业生态学的研究及发展。 相似文献
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生态农业建设中的政府行为探讨 总被引:2,自引:1,他引:1
建设生态农业是农业进一步发展的必然选择。生态农业生产中的系统性、协调性以及可持续性等特征,决定了发展生态农业离不开政府的调控与支持。此外,解决外部性问题以及提供建设所需的公共品,也是政府的主要职责。然而,当前政府在扶持生态农业建设中还存在着制度体系建设不完善、资金扶持力度不足等状况,限制了生态农业的持续快速发展。为此,应当通过培养生态农业意识、完善制度体系、推进生态农业产业化以及开发相应的科学技术等途径,来推进生态农业的建设步伐。 相似文献
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江西省生态农业发展现状与对策分析 总被引:5,自引:0,他引:5
在全面分析江西省生态农业建设现状和大力推广生态农业模式的基础上 ,针对制约本省生态农业建设与发展所存在的问题和症结 ,提出了生态农业建设与发展的对策及措施。 相似文献
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庭院生态农业是江西整个生态农业的重要组成部分。发展庭院生态农业,对于促进农业可持续发展,建设资源节约型、环境友好型社会具有重要的现实意义。本文首先简述了江西庭院资源概况;接着分析了发展庭院生态农业的重要意义;之后,重点讨论了江西庭院生态农业的类型、模式及效益;最后,对进一步发展江西庭院生态农业提出了若干的对策与建议。本文对促进当前江西乃至南方类似地区庭院生态农业的可持续发展有重要参考价值。 相似文献
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推行生态农业建设的障碍分析与对策 总被引:6,自引:0,他引:6
建设生态农业是实现我国农业可持续发展的必然选择 ,但现阶段我国要全面推行生态农业 ,还存在诸多障碍因素 ,因此要加强生态农业的宣传教育和技术培训 ,加大人才培养和科研推广力度 ,建立生态农业信息网络 ,规范农村和农产品市场 ,健全法律法规制度 ,以促进生态农业建设快速健康发展。 相似文献
10.
通过对赣州市生态农业建设限制因素的分析,依据赣州生态农业市建设的目标,提出将赣州市划分为4个生态农业区,建设8项生态农业工程及其保障生态农业建设的主要措施。 相似文献
11.
中国华北地区近40年物候春季变化 总被引:17,自引:4,他引:17
根据华北地区7个观测站物候资料,分析了华北地区1963-1996年及北京1963-2005年物候春季的变化特征及其与气温的关系。结果表明:华北地区的物候春季有明显提早来临的趋势,而造成这一变化的主要因素是本地区近40 a来冬春季气温的明显上升。其中1963-1996年间华北地区1-3月及4月的平均气温分别上升了2.3℃与1.7℃,物候春季起止日期分别提前了9d和4d,因而使得春季长度也延长了5d;北京1963-2003年间1-3月及4月的平均气温分别上升了3.5℃与2.6℃,物候春季的起止日期分别提前了11d和10d,但春季长度没有明显变化。 相似文献
12.
Sediment denitrification in waterways in a rice-paddy-dominated watershed in eastern China 总被引:1,自引:0,他引:1
Xiaobo Li Yongqiu Xia Yuefei Li Todd M. Kana Sonoko D. Kimura Masanori Saito Xiaoyuan Yan 《Journal of Soils and Sediments》2013,13(4):783-792
Purpose
Rice-paddy-dominated watersheds in eastern China are intensively cultivated, and lands with two crops receive as much as 550–600 kg?ha–1?year–1 of nitrogen (N), mainly through the addition of N-based fertilizers. However, stream N concentrations have been found to be relatively low. Waterways in the watersheds are assumed to be effective “sinks” for N, minimizing its downstream movement. We directly measured net sediment denitrification rates in three types of waterways (ponds, streams/rivers, and a reservoir) and determined the key factors that control net sediment denitrification. Such information is essential for evaluating the impact of the agricultural N cycle on the quality of surface water.Materials and methods
The pond–stream–reservoir continuum was sampled every 2 months at nine sites in an agricultural watershed between November 2010 and December 2011. Net sediment N2 fluxes/net sediment denitrification rates were determined by membrane inlet mass spectrometry and the N2/Ar technique. A suite of parameters known to influence denitrification were also measured.Results and discussion
Net denitrification rates ranged between 28.2?±?18.2 and 674.3?±?314.5 μmol N2–N?m–2?h–1 for the streams, 23.7?±?23.9 and 121.2?±?38.7 μmol N2–N?m–2?h–1 for the ponds, and 41.8?±?17.7 and 239.3?±?49.8 μmol N2–N?m–2?h–1 for the reservoir. The mean net denitrification rate of the stream sites (173.2?±?248.4 μmol N2–N?m–2?h–1) was significantly higher (p?<?0.001) than that of the pond sites (48.3?±?44.5 μmol N2–N?m–2?h–1), and the three types of waterways all had significantly higher (p?<?0.01) mean net denitrification rates in summer than in other seasons. Linear regression and linear mixed effect model analysis showed that nitrate (NO3 ?–N) concentration in surface water was the primary controlling factor for net sediment denitrification, followed by water temperature. Using monitoring data on NO3 ?–N concentrations and temperature of the surface water of waterways and an established linear mixed effect model, total N removed through net sediment denitrification in the pond–stream–reservoir continuum was estimated at 46.8?±?24.0 t?year–1 from July 2007 to June 2009, which was comparable with earlier estimates based on the mass balance method (34.3?±?12.7 t?year–1), and accounted for 83.4 % of the total aquatic N. However, the total aquatic N was only 4.4 % of the total N input to the watershed, and thus most of the surplus N in the watershed was likely to be either denitrified or stored in soil.Conclusions
High doses of N in a rice-paddy-dominated watershed did not lead to high stream N concentrations due to limited input of N into waterways and the high efficiency of waterways in removing N through denitrification. 相似文献13.
天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:13,自引:1,他引:12
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
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天津半干旱地区不同种植年限菜田土壤微生物变化特征的研究 总被引:3,自引:0,他引:3
对天津周边半干旱地区不同种植年限的菜田土壤微生物状况调查研究表明 ,该地区土壤微生物以细菌为主 ,夏季微生物总量大大高于冬季 ;随着种菜年限的增加 ,耕层和亚耕层微生物总量都有增加趋势 ,其中细菌和放线菌增加明显 ,真菌有下降趋势 ;真菌类群分析表明 ,少数纤维素分解菌 ,如青霉 (Penicillium)、木霉 (Trichoderma)等为优势菌 ,而糖和木质素分解菌仅占少数。用尖孢镰刀霉 (Fusariumuoxysporum)、大肠杆菌 (Escherichia coli)接种不同种菜年限土壤 ,检测土壤拮抗菌状况发现 ,拮抗菌仅在种植年限长的老菜田的放线菌中发现。表明北方半干旱地区菜田土壤细菌为优势菌 ,主要存在于土壤微孔隙中 ;而适于生活在土壤疏松大孔隙中的真菌数量极少。应注意土壤结构的改良 ,为丰富土壤微生物提供良好的生态环境 相似文献
15.
Phytoremediation is an emerging technology based on the use of green plants to remove, contain, inactivate or destroy harmful
environmental pollutants. Recent developments in Europe and the USA show that the approach is somewhat different on both sides
of the Atlantic. In Europe, phytoremediation has more basically been research driven and, based on the outcomes, applications
have been envisaged. By contrast, the approach in the USA is more application and experience driven. In spite of a growing
track record of commercial success, more demonstration projects are needed to prove that phytoremediation is effective in
order to rigorously measure its underlying economics, and to expand its applications. More fundamental research is also required
to better understand the complex interactions between pollutants, soil, plant roots and micro-organisms at the rhizosphere
level, to increase the bioavailability of pollutants, to fully exploit the metabolic diversity of plants and, thus, to successfully
implement this new green technology. 相似文献
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Water, Air, & Soil Pollution - Epiphytic lichens were sampled in a Dutch national monitoring survey, which was carried out twice within 5 yr. The samples were analyzed by neutron activation... 相似文献
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Howard B. Ross 《Water, air, and soil pollution》1987,36(3-4):349-363
Trace metals (Cd, Cu, Fe, Mn, Pb, and Zn) concentrations in atmospheric precipitation have been routinely monitored in Sweden since the autumn of 1983. Concentrations are highest in southern Sweden and decrease northward. It is postulated that the long range transport of anthropogenic pollutants from the rest of Europe is the major source of Cd, Pb, and Zn in precipitation. Evidence for this hypothesis is that enrichment factors indicate anthropogenic origin, and Swedish atmospheric emissions of Zn and Cd are 2 to 3 times smaller than deposition fluxes. Also, Cd, Pb, and Zn concentrations are correlated in both space and time and are also well correlated with exSO4 +, a substance known to be of anthropogenic origin transported long distances. 相似文献
19.
不同种植模式下菜地土壤腐殖质组分特性的动态变化 总被引:12,自引:0,他引:12
通过在南京普朗克有机农场开展的9年长期定位监测,研究了有机(露地和大棚)和常规种植模式下蔬菜地耕层土壤有机碳和土壤腐殖质组分特性的动态变化。结果表明,有机露地、有机大棚和常规露地种植土壤有机碳含量分别从11.41、9.29、9.00 g k g-1提高至15.35、20.90、10.00 g kg-1;胡敏酸碳(CHA)分别从1.79、1.23、1.14 g kg-1提高至2.11、3.11、1.31 g kg-1;富里酸碳(CFA)分别从2.19、1.88、1.73 g kg-1提高至2.44、2.68、1.91 g kg-1。两种有机种植模式的土壤有机碳及腐殖质组分含量增加达到显著水平,而常规种植模式下的变化不显著。两种有机种植模式下表征土壤腐殖质品质的胡/富比(CHA/CFA)、胡敏酸占总腐殖物质的比例(PQ值)均高于常规种植模式,土壤富里酸的E4/E6值、色调系数(ΔlogK)值随着种植时间增加的幅度较常规种植模式更大,土壤胡敏酸芳化度呈现先降低后增高的趋势,但在常规种植下变化不明显。说明土壤在长期有机种植模式下不仅更有利于土壤有机碳的积累,而且能促进土壤腐殖化进程。 相似文献
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Jenny Sundberg Per-Erik Karlsson Linda Schenk Hâkan Pleijel 《Water, air, and soil pollution》2006,173(1-4):339-354
Ozone (O3) concentration and air temperature/relative humidity were monitored using diffusive samplers (weekly, 3 m above ground) and Tinytag loggers (10 min sampling, 1 m above ground, self-ventilating radiation shields), respectively, in the forested landscape of south-west Sweden, 40 km north-east of Gothenburg. Two forest sites were included, one at a hilltop (175 m a.s.l.), and one in a nearby (~1 km) valley (110 m a.s.l.). In addition, a valley site (~3 km from the forest sites, 60 m a.s.l.) in an agricultural landscape was included, where ozone was measured using both a UV-based monitor and diffusive sampling. At the agricultural site measurements of temperature and relative humidity were made using a radiation shield with forced ventilation and with Tinytags, as on the forest sites, in addition to observations of wind speed and the vertical temperature gradient. Furthermore, comparison with O3 concentrations at urban and coastal sites in the region was made. The temperature dependent, systematic error of using a self-ventilating radiation shield was estimated and corrected for. It was found that the elevated forested site experienced higher O3 concentrations and lower evening cooling rates in calm situations as compared to the forest site in the valley and in particular as compared to the agricultural site. This can be explained by a stronger coupling with the planetary boundary layer at the elevated site and more pronounced night-inversions at the valley sites. The difference in weekly O3 concentration between the two forested sites was correlated with the difference in average minimum night-time temperature. The coastal site had the highest ozone concentrations, related largely, but not fully, to higher night-time O3 concentrations. The urban site showed a depression in O3 concentration associated with the combination of large NO emissions and slow air mixing during the morning traffic rush hours. 相似文献