检索结果-南通市图书馆

soil and Vegetation Seasonal Changes in the Grazing Andean Mountain Grasslands

Journal of Mountain Science 2014年第5期11卷 1123-1137页

作者： MU?OZ María ángeles FAZ ángel Sustainable use Management and Reclamation Soil and Water Research Group Agriculture and Science Technology Department Technical University of Cartagena

Andean grasslands ecosystems are fragile environments with rigorous climatologic conditions and low and variable food for the grazing. The Apolobamba area is located in the Bolivian Andean Mountains. Its high grasslands provide a natural habitat for wild and domestic camelids such as vicuna(Vicugna vicugna) and alpaca(Lama pacos). The botanical diversity plays an essential role in maintaining vital ecosystem functions. The objectives of this research were to determine the seasonal changes in soil properties, to study the vegetation changes during the wet and dry seasons and the influence of soil properties and camelid densities on the vegetation in the Apolobamba grasslands. Four zones with different vicuna populations were selected to be studied. The following soil parameters were determined: total organic carbon, total nitrogen, available phosphorous, cation exchange capacity, exchangeable cations, pH and texture. The vegetation season changes were studied through botanical identification, above-ground biomass, plant cover and species richness. Results showed that some soil properties such as C/N ratio, CEC, silt and clay percentages kept stable against the seasonal changes. Generally, soil nutrients were relatively higher during the dry season in the surface and subsurface. The results did not point out the predominant vegetation growth during the wet season. The seasonal vegetation growth depended on each species. Thegood soil fertility corresponded to the highest plant cover. soil fertility presented no influence on the above-ground biomass of the collected species. The negative influence of camelid grazing on soil properties could not be assessed. However, overgrazing could affect some plant species. Therefore, protection is needed in order to preserve the biodiversity in the Andean mountain grasslands.

关键词： Biodiversity Camelid grazing High grasslands Plant communities soil properties

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 heavy metal contents in animal feeds and manures in an intensive animal production region of China

引用

Journal of Environmental Sciences 2013年第12期25卷 2435-2442页

作者： Hui Wang Yuanhua Dong Yunya Yang Gurpal S.Toor Xumei Zhang Key Laboratory of soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of Sciences soil and Water quality Laboratory Gulf Coast Research and Education CenterUniversity of Florida Taicang soil Management Station

The 360 feed and manure samples were collected from 150 animal farms in Jiangsu Province, China and analyzed for heavy metals. Concentrations of Zn and Cu in animal feeds were 15.9-2041.8 and undetected-392.1 mg/kg respectively, while Hg, As, Pb, Cd, and Cr in all feeds were below 10 mg/kg. Concentrations of Cu, Zn, and Cr in animal manures were 8.4-1726, 39.5-11379, and 1.0-1602 mg/kg respectively, while As, Cd, Hg, and Pb were 〈 10 mg/kg. The concentration of Cu, Zn, As and Cr in animal feed and manure were positively correlated （p 〈 0.001）, but the Cd, Hg, and Pb were not statistically correlated between the feed and the manure. Concentrations of Cu and Zn were highest in pig feed and manure, followed by poultry and dairy feeds and manures. During 1990- 2008, Cu, Zn, As, Cr, Cd contents increased by 771%, 410%, 420%, 220%, and 63% in pig manure, 212%, 95%, 200%, 791%, and -63% in dairy manure, and 181%, 197%, 1500%, 261, and 196% in poultry manure. Most of the increases occurred from 2002 to 2008, which reflects the extensive use of feed additives after 2002. In contrast, Pb and Hg in manures continuously decreased from 1990 to 2008. The results suggest that the heavy metal contents in animal manure have been greatly increased over 18 years and the contribution of manures to soil should be considered.

关键词： animal manures heavy metal change

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

Mycorrhizal fungi mitigate nitrogen losses of an experimental grassland by facilitating plant uptake and soil microbial immobilization

引用

Pedosphere 2024年第2期34卷 399-410页

作者： Yangyang JIA Marcel G.A.VAN DER HEIJDEN Alain Y.VALZANO-HELD Markus JOCHER Florian WALDER Postdoctoral Mobile Station of Ecology College of Ecology and EnvironmentXinjiang UniversityÜrümqi 830046China research group Plant-soil Interactions AgroscopeZürich 8046Switzerland research group Climate and Agriculture AgroscopeZürich 8046Switzerland Department of Plant and Microbial Biology University of ZürichZürich 8008Switzerland research group soil quality and soil use AgroscopeZürich 8046Switzerland

Nitrogen(N)is one of the most limited nutrients of terrestrial ecosystems,whose losses are prevented in tightly coupled cycles in finely tuned *** change-induced N enrichment through atmospheric deposition and application of vast amounts of fertilizer are now challenging the terrestrial N *** mycorrhizal fungi(AMF)are known drivers of plant-soil nutrient fluxes,but a comprehensive assessment of AMF involvement in N cycling under global change is still ***,we simulated N enrichment by fertilization(low/high)in experimental grassland microcosms under greenhouse conditions in the presence or absence of AMF and continuously monitored different N pathways over nine *** found that high N enrichment by fertilization decreased the relative abundance of legumes and the plant species dominating the plant community changed from grasses to forbs in the presence of AMF,based on aboveground *** presence of AMF always maintained plant N:phosphorus(P)ratios between 14 and 16,no matter how the soil N availability *** in plant N:P ratios due to the increased plant N and P uptake might thus be a primary pathway of AMF altering plant community ***,we constructed a comprehensive picture of AMF’s role in N cycling,highlighting that AMF reduced N losses primarily by mitigating N leaching,while N_(2)O emissions played a marginal *** mycorrhizal fungi reduced N_(2)O emissions directly through the promotion of N_(2)O-consuming *** underlying mechanism for reducing N leaching is mainly the AMF-mediated improved nutrient uptake and AMF-associated microbial *** results indicate that synergies between AMF and other soil microorganisms cannot be ignored in N cycling and that the integral role of AMF in N cycling terrestrial ecosystems can buffer the upcoming global changes.

关键词： N cycling N enrichment N uptake N:P ratio plant community structure symbiotic soil fungi

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

Scenario Analysis of Tillage, Residue and Fertilization Management Effects on soil Organic Carbon Dynamics

引用

Pedosphere 2005年第4期15卷 473-483页

作者： WANG Xiao-Bin CAI Dian-Xiong W. B. HOOGMOED O. OENEMA U. D. PERDOK soil and Fertilizer Institute Chinese Academy of Agricultural Sciences Beijing 100081 （China） soil Technology group Wageningen University P. O. Box 17 6700 AA Wageningen （The Netherlands） soil quality group Wageningen University P. O. Box 8005 6700 EC Wageningen （The Netherlands）

Based on data from 10-year field experiments on residue/fertilizer management in the dryland farming region of northern China, Century model was used to simulate the site-specific ecosystem dynamics through adjustment of the model＇s parameters, and the applicability of the model to propose soil organic carbon （SOC） management temporally and spatially, in cases such as of tillage/residue/fertilization management options, was identified v/a scenario *** between simulations and actual measurements were in close agreement when appropriate applications of stover,manure and inorganic fertilizer were combined. Simulations of extreme C/N ratios with added organic materials tended to underestimate the measured effects. Scenarios of changed tillage methods, residue practices and fertilization options showed potential to maintain and enhance SOC in the long run, while increasing inorganic N slowed down the SOC turnover rate but did not create a net C sink without any organic C input. The Century model simulation showed a good relationship between annual C inputs to the soil and the rate of C sequestration in the top 20 cm layer and provided quantitative estimations of changes in parameters crucial for sustainable land use and management. Conservation tillage practices for sustainable land use should be integrated with residue management and appreciable organic and inorganic fertilizer application, adapted according to the local residue resource, soil fertility and production conditions. At least 50% residue return into the soil was needed annually for maintenance of SOC balance, and manure amendment was important for enhancement of SOC in small crop-livestock systems in which crop residue land application was limited.

关键词： Century model conservation tillage crop residue dryland soil organic carbon

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

Physics-informed deep learning for one-dimensional consolidation

引用

Journal of Rock Mechanics and Geotechnical Engineering 2021年第2期13卷 420-430页

作者： Yared W.Bekele Rock and soil Mechanics group SINTEF ASTrondheimNorway

Neural networks with physical governing equations as constraints have recently created a new trend in machine learning *** this context,a review of related research is first presented and *** potential offered by such physics-informed deep learning models for computations in geomechanics is demonstrated by application to one-dimensional(1D)*** governing equation for 1D problems is applied as a constraint in the deep learning *** deep learning model relies on automatic differentiation for applying the governing equation as a constraint,based on the mathematical approximations established by the neural *** total loss is measured as a combination of the training loss(based on analytical and model predicted solutions)and the constraint loss(a requirement to satisfy the governing equation).Two classes of problems are considered:forward and inverse *** forward problems demonstrate the performance of a physically constrained neural network model in predicting solutions for 1D consolidation *** problems show prediction of the coefficient of ***’s problem,with varying boundary conditions,is used as a numerical example and the deep learning model shows a remarkable performance in both the forward and inverse *** the application demonstrated here is a simple 1D consolidation problem,such a deep learning model integrated with a physical law has significant implications for use in,such as,faster realtime numerical prediction for digital twins,numerical model reproducibility and constitutive model parameter optimization.

关键词： Physics-informed deep learning Consolidation Forward problems Inverse problems

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

Biological weathering of phlogopite during enriched vermicomposting

引用

Pedosphere 2021年第3期31卷 440-451页

作者： Fariba JAFARI Hossein KHADEMI Vajihe SHAHROKH Angel FAZ CANO Jose A.ACOSTA Farhad KHORMALI Department of soil Science College of AgricultureIsfahan University of TechnologyIsfahan 84156-83111Iran Sustainable use Management and Reclamation of Soil and Water Research GroupUniversidad Politécnica de CartagenaPaseo Alfonso ⅩⅢ48CartagenaMurcia 30203Spain Department of soil Science Gorgan University of Agricultural Science and Natural ResourcesGorgan 49189-43464Iran

As the dominant macrofauna in many soils,earthworms play a significant role in mineral weathering and nutrient release from mineral structures into available forms for root *** is a trioctahedral micaceous mineral that can be weathered to other minerals through release of its interlayer potassium(K).In this study,we investigated the effect of earthworm activities and associated microbial communities on phlogopite weathering during the production of phlogopite-enriched vermicompost with different quantities of phlogopite *** experiment was run under laboratory conditions using three levels of phlogopite(0,20%and 40%by weight)in *** Petri dish contained 20 g of a mixture of cow manure and phlogopite,and vermicomposting process was performed by inoculation of eight Eisenia foetida *** in clay mineralogy and C/N ratio in each dish were assessed at days 0,45,90,135,and 180 during *** results indicated that phlogopite was partially weathered to vermiculite and interstratified mica-vermiculite during the vermicomposting *** rate of weathering was higher during the early stages of vermicomposting(the first 90 d).The weathering of phlogopite was influenced considerably by the activity of earthworms and associated microbial communities during the organic matter transformation *** the early stages of the process,the weathering rate for different levels of phlogopite was not significantly different,but over time it accelerated steadily,and the difference increased.

关键词： C/N ratio earthworm Eisenia foetida enriched vermicompost mineral weathering weathering rate X-ray diffraction

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

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

引用

Journal of Environmental Sciences 2007年第5期19卷 584-590页

作者： WANG Fang JIANG Xin BIAN Yong-rong YAO Fen-xia GAO Hong-jian YU Gui-fen Jean Charles MUNCH Reiner SCHROLL State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Institute of soil Ecology GSF-National Research Center for Environment and Health Neuherberg 85764 Germany

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides （OCPs） were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX （DDD, DDE and DDT） had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p＇-（DDD＋DDE）/DDT in soils under three land usages were： paddy field 〉 tree land 〉 fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p＇-（DDD＋DDE）/DDT 〉1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.

关键词： DDT HCH land-use pesticide residue degradation

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

Impact of enclosure management on soil properties and microbial biomass in a restored semi-arid rangeland, Kenya

引用

Journal of Arid Land 2014年第5期6卷 561-570页

作者： Stephen M MUREITHI Ann VERDOODT Charles KK GACHENE Jesse T NJOKA Vivian O WASONGA Stefaan De NEVE Elizabeth MEYERHOFF Eric Van RANST Laboratory of soil Science Department of Geology and Soil Science Ghent University Department of Land Resources Management and Agricultural Technology University of Nairobi research Unit of soil Degradation and Conservation Department of Soil Management Ghent University Rehabilitation of Arid Environments Trust

Rangeland degradation is a serious problem throughout sub-Saharan Africa and its restoration is a challenge for the management of arid and semi-arid areas. In Lake Baringo Basin of Kenya, communities and individual farmers are restoring indigenous vegetation inside enclosures in an effort to combat severe land degradation and address their livelihood problems. This study evaluated the impact of enclosure management on soil properties and microbial biomass, being key indicators of soil ecosystem health. Six reseeded communal enclosures using soil embankments as water-harvesting structures and strictly regulated access were selected, varying in age from 13 to 23 years. In six private enclosures, ranging from 3 to 17 years in age, individual farmers emulated the communal enclosure strategy and restored areas for their exclusive use. Significant decreases in bulk density, and increases in the soil organic carbon, total nitrogen and microbial biomass contents and stocks were found in the enclosures as compared with the degraded open rangeland. In the private enclosures, the impact of rehabilitation on the soil quality was variable, and soil quality was in general lower than that obtained under communal management. The significant increase of absolute stocks of carbon, nitrogen and microbial biomass compared to the degraded open rangeland indicates the potential for the restoration of soil quality through range rehabilitation. Over-sowing with indigenous legume fodder species could improve total nitrogen content in the soil and nutritional value of the pastures as well.

关键词： rangeland degradation enclosures microbial biomass rehabilitation reseeding soil quality Kenya

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

Object-Based Method Outperforms Per-Pixel Method for Land Cover Classification in a Protected Area of the Brazilian Atlantic Rainforest Region

引用

Pedosphere 2013年第3期23卷 290-297页

作者： T.RITTL M.COOPER R.J.HECK M.V.R.BALLESTER Department of soil quality University of Wageningen Department of soil Science University of So Paulo School of Environmental Sciences University of Guelph Center for Nuclear Energy in Agriculture (CENA) University of So Paulo

Conventional image classification based on pixels hinders the possibilities to obtain information contained in images, while modern object-based classification methods increase the acquisition of information about the object and the context in which it is inserted in the image. The objective of this study was to investigate the performance of different classification methods for land cover mapping in the vicinity of the Alto Ribeira Tourist State Park, a Brazilian Atlantic rainforest area. Two classification methods were tested, including i） a hybrid per-pixel classification using the image processing software ERDAS Imagine version 9.1 and ii） an object-based classification using the software eCognition version 5. In the first method, six different classes were established, while in the second method, another two classes were established in addition to the six classes in the first method. Accuracy assessment of the classification results presented showed that the object-based classification with a Kappa index value of 0.8687 outperformed the per-pixel classification with a Kappa index value of 0.2224. Application of the user＇s knowledge during the object-based classification process achieved the desired quality; therefore, the use of inter-relationships between objects, superelasses, subclasses, and neighboring classes were critical to improving the efficiency of land cover classification.

关键词： accuracy assessment image classification Kappa index user's knowledge

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

Potential Effect of Conservation Tillage on Sustainable Land use: A Review of Global Long-Term Studies

引用

Pedosphere 2006年第5期16卷 587-595页

作者： WANG Xiao-Bin CAI Dian-Xiong W.B.HOOGMOED O.OENEMA U.D.PERDOK State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 （China） Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences Beijing 100081 （China） Farm Technology group Wageningen University P. O. Box 17 6700 AA Wageningen （The Netherlands） soil quality group Wageningen University P.O.Box 8005 6700 EC Wageningen （The Netherlands）

Although understood differently in different parts of the world, conservation tillage usually includes leaving crop residues on the soil surface to reduce tillage. Through a global review of long-term conservation tillage research, this paper discusses the long-term effect of conservation tillage on sustainable land use, nutrient availability and crop yield response. research has shown several potential benefits associated with conservation tillage, such as potential carbon sequestration, nutrient availability, and yield response. This research would provide a better perspective of the role of soil conservation tillage and hold promise in promoting application of practical technologies for dryland farming systems in China.

关键词： conservation tillage no-till reduced tillage residue management

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：