检索结果-南通市图书馆

Denitrification Losses and N_2O Emissions from Nitrogen Fertilizer Applied to a Vegetable Field

Pedosphere 2006年第3期16卷 390-397页

作者： CAO Bing He Fa-Yun Xu Qiu-Ming Yin Bin CAI Gui-Xin state Key laboratory of soil and sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Graduate school of the chinese academy of sciences Beijing 100039 （China） institute of Plant Nutrition and Resources Beijing Academy of Agricultural and Forestry Sciences Beijing 100089 （China）

A field experiment was conducted on chinese cabbage （Brassica campestris L. ssp. pekinensis （Lour.） Olsson） in a nanjing suburb in 2003. The experiment included 4 treatments in a randomized complete block design with 3.replicates： zero chemical fertilizer N （CK）; urea at rates of 3.0 kg N ha^-1 （U3.0） and 600 kg N ha^-1 （U600）, both as basal and two topdressings; and polymer-coated urea at a rate of 180 kg N ha^-1 （PCU180） as a basal application. The acetylene inhibition technique was used to measure denitrification （N2 ＋ N2O） from intact soil cores and N2O emissions in the absence of acetylene. Results showed that compared to （3. total denitrification losses were significantly greater （P ≤ 0.05） in the PCU180, U3.0, and U600 treatments,while N2O emissions in the U3.0 and U600 treatments were significantly higher （P ≤ 0.05） than （3.. In the U3.0 and U600 treatments peaks of denitrification and N2O emission were usually observed after N application. In the polymer-coated urea treatment （PCU180） during the period 20 to 40 days after transplanting, higher denitrification rates and N2O fluxes occurred. Compared with urea, polymer-coated urea did not show any effect on reducing denitrification losses and N2O emissions in terms of percentage of applied N. As temperature gradually decreased from transplanting to harvest, denitrification rates and N2O emissions tended to decrease. A significant （P ≤0.01） positive correlation occurred between denitrification （r = 0.872） or N2O emission （r = 0.781） flux densities and soil temperature in the CK treatment with a stable nitrate content during the whole growing season.

关键词： denitrification loss N2O emission polymer-coated urea urea vegetable field

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of Caragana Korshinskii Kom. cover on runoff, sediment yield and nitrogen loss

引用

International Journal of sediment Research 2010年第3期25卷 245-257页

作者： Guan-Hua ZHANG1,Guo-Bin LIU2?, and Guo-Liang WANG3. Ph.D., College of Resource and Environment, Northwest A and F University YangLing, shaanxi 712100, china, institute of soil and Water Conservation, {3. academy of science and Ministry of Water Resources, YangLing shaanxi 712100, china. 2 Prof., Researcher. institute of soil and Water Conservation, {3. academy of science and Ministry of Water Resources, YangLing shaanxi 712100, china, College of Resource and Environment, Northwest A and F University, YangLing, shaanxi 712100, china, 3.Assistant Researcher, institute of soil and Water Conservation, {3. academy of science and Ministry of Water Resources, YangLing shaanxi 712100, china. [a] Ph.D. College of Resource Environment Northwest A F University YangLing Shaanxi 712100 China Institute of Soil Water Conservation Chinese Academy of Science Ministry of Water Resources YangLing Shaanxi 712100 China [b] Prof. Researcher. Institute of Soil Water Conservation Chinese Academy of Science Ministry of Water Resources YangLing Shaanxi 712100 China College of Resource Environment Northwest A F University YangLing Shaanxi 712100 China [c] Assistant Researcher Institute of Soil Water Conservation Chinese Academy of Science Ministry of Water Resources YangLing Shaanxi 712100 China

soil erosion is serious in the Loess Plateau of china. Deposition of the eroded sediment in lakes or rivers may lead to eutrophication, because the sediment carries a lot of nutrients. Field experiments were conducted to study soil erosion and loss of nitrogen (N) from a 15o hillslope with 3.% (low) or 80% (high) coverage of the shrub Caragana korshinskii Kom. A bare soil plot was used for the comparison. The results showed that Caragana korshinskii cover significantly reduced runoff and soil erosion. In comparison to the bare soil plot, the vegetation covered plots had about 20% less runoff and 65% less sediment. In general, the concentration of N in both runoff water and the eroded sediment decreased with time and approached a steady value. However, the species of nitrate nitrogen (NO3. was exceptional which increased with time slightly. The soil erosion caused an N loss of about 250 mg/m2 for the bare soil plot, the low coverage of Caragana korshinskii reduced the N loss by 20% and the high coverage of Caragana korshinskii reduced the N loss by 40%. Moreover, the amount of total N in eroded sediment was 2 to 3.times higher than the value in runoff water. In the total N loss, the organic N was about 75-80%. Nevertheless, inorganic N in runoff water was 5 to 10 times higher than the value in eroded sediment. The species of NO3.was obviously higher than the species of ammonium nitrogen (NH4). NO3.was the main species of inorganic N loss and was about two thirds of total. The organic N was the main species of N in the eroded sediment.

关键词： C. korshinskii cover Runoff sediment Nitrogen loss simulated rainfall

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Atmospheric sulfur Deposition for a Red soil Broadleaf Forest in southern china

引用

Pedosphere 2004年第3期14卷 323-330页

作者： XUCheng-Kai HUZheng-Yi CAIZu-Cong WANGTi-Jian HEYuan-Qiu CAOZhi-Hong stateKeyLaboratoryofsoilandsustainableAgriculture InstituteofSoilScienceChineseAcademyofSciencesNanjing210008（China） DepartmentofAtmosphericscience NanjingUniversityNanjing210093（China）

A two-year study in a typical red soil region of southern china was conductedto determine 1) the dry deposition velocity (V_d) for sO_2 and particulate sO_4^(2-) above abroadleaf forest, and 2) atmospheric sulfur fluxes so as to estimate the contribution of variousfractions in the total. Using a resistance model based on continuous hourly meteorological data,atmospheric dry sulfur deposition in a forest was estimated according to V_d and concentrations ofboth atmospheric sO_2 and particulate sO_4^(2-). Meanwhile, wet s deposition was estimated based onrainfall and sulfate concentrations in the rainwater. Results showed that about 99% of the drysulfur deposition flux in the forest resulted from sO_2 dry deposition. In addition, the observeddry s deposition was greater in 2002 than in 2000 because of a higher average concentration of sO_2in 2002 than in 2000 and not because of the average dry deposition velocity which was lower for sO_2in 2002. Also, dry sO_2 deposition was the dominant fraction of deposited atmospheric sulfur inforests, contributing over 69% of the total annual sulfur deposition. Thus, dry sO_2 depositionshould be considered when estimating sulfur balance in forest ecological systems.

关键词： atmospheric sulfur deposition dry deposition velocity particulatesO_4^(2-) red soil, sO_2

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A coupled elasto-plastic-damage mechanical model for marble

引用

science china(Technological sciences) 2011年第S1期54卷 228-234页

作者： ZHOU Hui 1,ZHANG Kai 2 & FENG XiaTing 1 1.state Key Laboratory of Geomechanics and Geotechnical Engineering,institute of Rock and soil Mechanics,{3. academy of sciences,Wuhan 43.071,china 2 state Key Laboratory for Geomechanics and Deep Underground Engineering,china University of Mining&Technology,Xuzhou 221008,china 1. state Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan 430071 China 2. state Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining & Technology Xuzhou 221008 China

A profound understanding of the mechanical behaviors of marble is very important for the design and construction of deep diversion tunnels in Jinping II hydropower *** this paper,a coupled elasto-plastic-damage mechanical model is presented for Jinping ***,the experimental investigations on Jinping marble are ***,based on the framework of continuum damage and plastic theories,a general mechanical model is proposed to predict the mechanical responses of Jinping *** proposed model is used to simulate the triaxial compressive tests,and there is a general good agreement between experimental data and numerical predictions in a qualitative *** proposed model is able to capture the main features of Jinping marble observed in experiments,such as progressive yielding process,damage induced by plastic distortion,dilation,elastic degradation and stress sensitivity.

关键词： mechanical model damage elasto-plastic coupling marble

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Chemical and Microbiological Parameters of Paddy soil Quality as Affected by Different Nutrient and Water Regimes

引用

Pedosphere 2005年第3期15卷 369-378页

作者： YANGChang-Ming YANGLin-Zhang YANTing-Mei stateKeyLab.ofPollutionControlandResourceReuse CollegeofEnvironmentalScienceandEngineeringTongjiUniversityShanghai200092（China） instituteofsoilscience ChineseAcademyofSciencesP.O.Box821Nanjing210008（China）

A field experiment was conducted from 1999 to 2002 to compare and evaluate the effects of nutrient and water regimes on paddy soil quality by investigating soil chemical and microbiological parameters. Four nutrient regimes, a control, chemical fertilizers only (CF), chemical fertilizers with swine manure (sM), and chemical fertilizers with wheat straw (Ws), and two soil moisture regimes, continuous waterlogging (CWL) and alternate wetting and drying (AWD), were investigated. With sM and Ws total organic carbon and total nitrogen in the paddy soil were significantly higher (P se with CF. A similar effect for organic amendments was observed in the soil light fraction organic C (LFOC), water-soluble carbohydrates (WsC), and water-soluble organic C (WsOC). CWL, in particular when swine manure was incorporated into the paddy soil, markedly decreased soil redox potential (Eh) and increased total active reducing substances (ARs). Meanwhile, as compared to CF, sM and Ws significantly (P sed soil microbial biomass C (MBC) and mineralizable carbon, with differences in AWD being higher than CWL. In addition, sM and Ws treatments significantly (P ss and grain yield, with AWD being greater than CWL. Thus, for ecologically sustainable agricultural management of paddy soils, long-term waterlogging should be avoided when organic manure was incorporated into paddy soil.

关键词： biological index of fertility nutrient regimes paddy soil quality water regimes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

soil Heavy Metal Pollution Around the Dabaoshan Mine,Guangdong Province,china

引用

Pedosphere 2007年第5期17卷 588-594页

作者： ZHOU Jian-Min DANG Zhi CAI Mei-Fang LIU Cong-Qiang College of Environmental science and Engineering South China University of Technology Guangzhou 510640 （China） Guangdong Key Laboratory of Agro-Environment Integrated Control Guangdong Institute of Eco-Environment and Soil Science Guangzhou 510650 （China） state Key Laboratory of Environment Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 （China）

soil contamination in the vicinity of the Dabaoshan Mine, Guangdong Province, china, was studied through determi- nation of total concentrations and chemical speciation of the toxic metals, Cu, Zn, Cd, and Pb, using inductively coupled plasma mass spectrometry. The results showed that over the past decades, the environmental pollution was caused by a combination of Cu, Zn, Cd, and Pb, with tailings and acid mine drainage being the main pollution sources affecting soils. significantly higher levels （P ≤ 0.05） of Cu, Zn, Cd, and Pb were found in the tailings as compared with paddy, garden, and control soils, with averages of 1486, 2516, 6.42, and 429 mg kg^-1, respectively. These metals were continuously dispersed downstream from the tallings and waste waters, and therefore their concentrations in the paddy soils were as high as 567, 1 140, 2.48, and 191 mg kg^-1, respectively, being significantly higher （P ≤ 0.05） as compared with those in the garden soils. The results of sequential extraction of the above metals from all the soil types showed that the residual fraction was the dominant form. However, the amounts of metals that were bound to Fe-Mn oxides and organic matter were relatively higher than those bound to carbonates or those that existed in exchangeable forms. As metals could be transformed from an inert state to an active state, the potential environmental risk due to these metals would increase with time.

关键词： chemical speciation combined pollution index (CPI) contaminated soil heavy metals

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Environmental Issues Related to Chemical Fertilizer Use in china

引用

Pedosphere 1996年第4期6卷 289-303页

作者： CAO ZHIHONG (LMCP, institute of soil science, Academia sinica, P. O. Box 821,{3. china) LMCP Institute of Soil Science Academia Sinica P. O. Box 821 Nanjing 210008 China

The current status of chemical fertilizers production and consumption in china as well as their important roles in chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use. On the one hand, the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs. On the other hand, the production and consumption of chemical fertilizers in china are obviously not balanced. In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to {3. erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies. Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasing {3. productivity and keeping sustainable agriculture development but also in mimimizing their detrimental effects on the environment.

关键词： chemical fertilizer environmental issues modern agriculture

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nitrate Accumulation in soil Profile of Dry Land Farming in Northwest china

引用

Pedosphere 2003年第4期13卷 367-374页

作者： FAN Jun, HAO Ming-De and sHAO Ming-Anstate Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau, institute of soil and Water Conservation, the {3. academy of sciences, Yangling 712100 (china). state Key Laboratory of soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water Conservation the Chinese Academy of Sciences Yangling 712100 China

A long-term fertilizer experiment on dry land of the Loess Plateau, northwestchina, has been conducted since 1984 to study the distribution and accumulation of NO_3.N down to adepth of 400 cm in the profile of a coarse-textured dark loessial soilafter continuous winter wheatcropping. Thirteen fertilizer treatments consisted of four levels of N and P applied alone or incombination. Annual N and P (P_2O_5) rates were 0, 45, 90, 13. and 180 kg ha^(-1). After 1.successive cropping cycles, the soil samples were taken from each treatment for analysis of NO_3.Nconcentration. The results showed that NO_3.N distribution in the soil profile was quite differentamong the treatments. The application of fertilizer N alone resulted in higher NO_3.N concentrationin the soil profile than the combined application of N and P, showing that application of P couldgreatly reduce the NO_3.N accumulation. With an annual application of 180 kg N ha^(-1) alone, a peakin NO_3.N accumulation occurred at 140 cm soildepth, and the maximum NO_3.N concentration in the{1.s was 67.92 mg kg^(-1). The amount of NO_3.N accumulated in the soil profile decreased as thecumulative N uptake by the winter wheat increased. Application of a large amount of N resulted inlowerN recoveries in winter wheat and greater NO_3.N accumulation in soil profile. KO_3.N did notenter underground water in the study region; therefore, there is no danger of underground waterpollution. Amount of NO_3.N accumulation can be predicted by an equation according to annual N and Prates based on the results of this experiment.

关键词： dry land long-term fertilizer experiment NO_3.N accumulation wheat

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Nitrate and Ammonium Leaching in Variable-and Permanent-Charge Paddy soils

引用

Pedosphere 2010年第2期20卷 209-216页

作者： XIONG Zheng-Qin HUANG Tai-Qing MA Yu-Chun XING Guang-Xi ZHU Zhao-Liang College of Resources and Environmental sciences Nanjing Agricultural University Nanjing 210095 （China） state Key Laboratory of soil and sustainable Agriculture Institute of Soil Science Chinese Academy of SciencesNanjing 210008 （China）

A variable-charge （VC） and a permanent-charge paddy soil （PC） were selected to study nitrate-N （NO3.--N） and ammonium-N （NH4^＋-N） leaching with N isotopes for one consecutive year. An irrigation and intermittent drainage pattern was adopted to mimic natural occurrence of rainfall during the upland crop season and drainage management during the flooded rice season. Treatments to each soil type were no-N controls （CK）, ^15N-labeled （NH4）2sO4 （Ns）, and milk vetch （NV） applied at a rate equivalent to 23. kg N ha^-1 to unplanted lysimeters, totaling six treatments in triplicates. Results indicated that the soil type dominated N leaching characteristics. In the case of PC, NO3.--N accounted for 78% of the total leached inorganic N; Ns was prone to leach three times more than the NV, being 8.2% and 2.4% of added ^15N respectively; and 〉 85% of leached NO3.N came from of the total inorganic N in leachate. Moreover, NH4^＋-N native N in the soil. In the case of VC, NH4^＋-N made up to 92% leaching was detected throughout the whole incubation, and was particularly high during the flooded season. NO3.--N leaching in VC occurred later at a lower rate compared to that in PC. The findings of this study indicate that NO3.--N leaching during the drained season in permanent-charge paddy soils and NH4^＋-N leaching in variable-charge soils deserve more attention for regional environmental control.

关键词： drained/flooded rotations fertilizer-derived nitrate ion movement lysimeter ^15N tracing technique

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Changes in soil solution Cu and Zn Following Application of Alkaline stab ilisedsewagesludgeand GammaIrradiation *1

引用

Pedosphere 1998年第2期8卷 134-142页

作者： YAN WEIDONG 1, LUO YONGMING 2 and P. CHRIsTIE 2 1 institute of soil science, the {3. academy of sciences, P.O Box 821, nanjing 21.008 (china) 2 Agricultural and Environmental science Department, the Queen’s University of Belfast, Ne

A glasshouse pot experiment was conducted to study changes in the solubility of copper and zinc in the soil plant system following heavy application of sewage sludge and partial sterilisation of the sludge/soil mixture. A slightly acid sandy loam was mixed with alkaline stabilised and composted urban sewage sludge solids (`Agri soil', 180 t hm -2 ), and the soil/sludge mixture was γ irradiated (10 kGy). The contrasts without the application of sewage sludge and γ irradiation were also included in the experiment. Perennial ryegrass (Lolium perenne cv. Magella) was grown on irradiated and unirradiated soils for 50 days. soil solution samples were obtained using soil suction samplers immediately before plant transplantation and every ten days thereafter. The soil solution samples were used directly for determination of Cu and Zn, together with pH, electrical conductivity (EC) and absorbance at wavelength 3.0 nm (A 3.0 ). Application of Agri soil led to a substantial increase in dissolved Cu and a significant decrease in dissolved Zn in the soil solution and these effects were accompanied by increased soil solution pH, EC and A 3.0 . The alkaline sludge product (Agri soil) in combination with γ irradiation also led to a pronounced elevation of Cu and A 3.0 but a marked decline in EC, indicating an increase in dissolved organic compounds and a decrease in the ionic strength of the soil solution. The dissolved Cu and Zn, EC and A 3.0 usually decreased while the pH increased after plant growth for 50 days.

关键词： copper γ irradiation sewage sludge soil solution zinc

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：