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Factors affecting trace element content in periurban market garden subsoil in Yunnan Province,China

Journal of Environmental Sciences 2011年第3期23卷 488-496页

作者： Yanqun zu Laurent Bock Christian Schvartz Gilles Colinet Yuan Li College of Resources and Environment Yunnan Agricultural University Kunming 650201 China Laboratory of Soil Science Gembloux Agro-bio Technology University Liege University Gembloux Belgium Laboratory of Soil and Environment Institute of Advanced Agriculture Catholic University Lille France

Field investigations were conducted to measure subsoil trace element content and factors influencing content in an intensive periurban market garden in Chenggong County, Yunnan Province, South-West China. The area was divided into three different geomorphological units： specifically, mountain （M）, transition （T） and lacustrine （L）. Mean trace element content in subsoil were determined for Pb （58.2 mg/kg）, Cd （0.89 mg/kg）, Cu （129.2 mg/kg）, and Zn （97.0 mg/kg）. Strong significant relationships between trace element content in topsoil and subsoil were observed. Both Pb and Zn were accumulated in topsoil （RTS （ratio of mean trace element in topsoil to subsoil） of Pb and Zn ≥1.0） and Cd and Cu in subsoil （RTS of Cd and Cu≤1.0）. subsoil trace element content was related to relief, stoniness, soil color, clay content, and cation exchange capacity. Except for 7.5 YR （yellow-red） color, trace element content increased with color intensity from brown to reddish brown. Significant positive relationships were observed between Fe content and that of Pb and Cu. Trace element content in mountain unit subsoil was higher than in transition and lacustrine units （M 〉 T 〉 L）, except for Cu （T 〉 M 〉 L）. Mean trace element content in calcareous subsoil was higher than in sandstone and shale. Mean trace element content in clay texture subsoil was higher than in sandy and sandy loam subsoil, and higher Cu and Zn content in subsoil with few mottles. It is possible to model Pb, Cd, Cu, and Zn distribution in subsoil physico-chemical characteristics to help improve agricultural practice.

关键词： trace elements subsoil topsoil relationships

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Denitrification Rate and Controlling Factors for Accumulated Nitrate in the Deep subsoil of Intensive Farmlands: A Case Study in the North China Plain

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Pedosphere 2019年第4期29卷 516-526页

作者： YUAN Haijing QIN Shuping DONG Wenxu HU Chunsheng Kiril MANEVSKI LI Xiaoxin Key Laboratory of Agricultural Water Resources Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 (China) University of Chinese Academy of Sciences Beijing 100049 (China) Department of Agroecology Aarhus University Tjele 8830 (Denmark)

Denitrification in subsoil(to a depth of 12 m) is an important mechanism to reduce nitrate(NO3^-) leaching into ***, regulating mechanisms of subsoil denitrification, especially those in the deep subsoil beneath the crop root zone, have not been well documented. In this study, soil columns of 0–12 m depth were collected from intensively farmed fields in the North China Plain. The fields had received long-term nitrogen(N) fertilizer inputs at 0(N0), 200(N200) and 600(N600) kg N ha^-1 year^-1. Main soil properties related to denitrification, i.e., soil water content, NO3^-, dissolved organic carbon(DOC), soil organic carbon(SOC),pH, denitrifying enzyme activity(DEA), and anaerobic denitrification rate(ADR), were determined. Statistical comparisons among the treatments were performed. The results showed that NO3^- was more heavily accumulated in the entire soil profile of the N600 treatment, compared to the N0 and N200 treatments. The SOC, DOC, and ADR decreased with increasing soil depth in all treatments,whereas considerable DEA was observed throughout the subsoil. The long-term fertilizer rates affected ADR only in the upper 4 m soil layers. The ADRs in the N200 and N600 treatments were significantly correlated with DOC. Multiple regression analysis indicated that DOC rather than DEA was the key factor regulating denitrification beneath the root zone. Additional research is required to determine if carbon addition into subsoil can be a promising approach to enhance NO3^- denitrification in the subsoil and consequently to mitigate groundwater NO3^- contamination in the intensive farmlands.

关键词： denitrifying enzyme activity dissolved organic carbon nitrate leaching soil organic carbon subsoil denitrification

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Effect of subsoil tillage depth on nutrient accumulation, root distribution, and grain yield in spring maize

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The Crop Journal 2014年第5期2卷 297-307页

作者： Hongguang Cai Wei Ma Xiuzhi Zhang Jieqing Ping Xiaogong Yan Jianzhao Liu Jingchao Yuan Lichun Wang Jun Ren Institute of Agricultural Resource and Environment Jilin Academy of Agricultural Sciences Institute of Crop Science Chinese Academy of Agricultural Sciences Department of Agronomy Purdue University 915 W State StreetWest Lafayette IN 47907 USA

A four-year field experiment was conducted to investigate the effect of subsoiling depth on root morphology, nitrogen(N), phosphorus(P), and potassium(K) uptake, and grain yield of spring maize. The results indicated that subsoil tillage promoted root development,increased nutrient accumulation, and increased yield. Compared with conventional soil management(CK), root length, root surface area, and root dry weight at 0–80 cm soil depth under subsoil tillage to 30 cm(T1) and subsoil tillage to 50 cm(T2) were significantly increased, especially the proportions of roots in deeper soil. Root length, surface area, and dry weight differed significantly among three treatments in the order of T2 > T1 > CK at the12-leaf and early filling stages. The range of variation of root diameter in different soil layers in T2 treatment was the smallest, suggesting that roots were more likely to grow downwards with deeper subsoil tillage in soil. The accumulation of N, P, and K in subsoil tillage treatment was significantly increased, but the proportions of kernel and straw were different. In a comparison of T1 with T2, the grain accumulated more N and P, while K accumulation in kernel and straw varied in different years. Grain yield and biomass were increased by 12.8% and 14.6% on average in subsoil tillage treatments compared to conventional soil treatment. Although no significant differences between different subsoil tillage depths were observed for nutrient accumulation and grain yield, lodging resistance of plants was significantly improved in subsoil tillage to 50 cm, a characteristic that favors a high and stable yield under extreme environments.

关键词： Spring maize subsoil tillage Root morphology Grain yield Nutrient accumulation

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Comparative study on foundation treatment methods of immersed tunnels in China

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Frontiers of Structural and Civil Engineering 2020年第1期14卷 82-93页

作者： Shaochun WANG Xuehui ZHANG Yun BAI Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Based on engineering practices of four typical traffic immersed tunnels built in China,this paper details the features of the four dominant foundation treatment methods for immersed tunnel construction:pile foundation,sand flow foundation,grouting foundation,and gravel bedding *** stress time-history of different method are specified first,plus a summary of settlement assessment method for foundation quality ***,a comprehensive comparison of settlement and cost of these four foundation treatment methods is conducted to highlights the specific merits,disadvantages and conditions encountered in each foundation treatment method,based on real projects *** findings of this article could henceforth be applied to foundation treatment work in immersed tube tunnel construction.

关键词： foundation treatment method immersed tunnel subsoil stress settlement

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Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China

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Pedosphere 2021年第5期31卷 683-693页

作者： Yusef KIANPOOR KALKHAJEH Biao HUANG Helle SORENSEN Peter EHOLM Hans Christian BHANSEN Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention School of Resources and EnvironmentAnhui Agricultural UniversityHefei 230036(China) Department of Plant and Environmental Sciences University of CopenhagenThorvaldsensvej 40Frederiksberg DK-1871 C(Denmark) Key Laboratory of Soil Environment and Pollution Remediation Institute of Soil ScienceChinese Academy of SciencesNanjing 210008(China) Sino-Danish Center for Education and Research(SDC) Beijing 101408(China) Data Science Lab Department of Mathematical SciencesUniversity of CopenhagenUniversitetsparken 5DK-2100 Copenhagen East(Denmark)

Over-fertilization has caused significant phosphorus(P)accumulation in Chinese greenhouse vegetable production(GVP)*** study,for the first time,quantified profile P accumulation directly from soil P measurements,as well as subsoil P immobilization,in three alkaline coarse-textured GVP soil profiles with 5(S5),15(S15),and 30(S30)years of cultivation in Tongshan,Southeast *** each profile,soil samples were collected at depths of 0-10(topsoil),10-20,20-40,40-60,60-80,and 80-100 *** accumulation was estimated from the difference in P contents between topsoil and parent material(60-100 cm subsoil).Phosphorus mobility was assessed from measurements of water-soluble P concentration(P_(Sol)).Finally,P sorption isotherms were produced using a batch sorption experiment and fitted using a modified Langmuir *** total P contents of 1980(S5),3190(S15),and 2330(S30)mg kg^(-1) were measured in the topsoils versus lower total P content of approximately 600 mg kg^(-1) in the 80-100 cm ***,topsoil PSol values were very high,varying from 6.4 to 17.0 mg L^(-1).The estimated annual P accumulations in the topsoils were 397(S5),212(S15),and 78(S30)kg ha^(-1) year^(-1).Sorption isotherms demonstrated the dominance of P desorption in highly P-saturated topsoils,whereas the amount of adsorbed P increased in the 80-100 cm subsoils with slightly larger P adsorption *** total P adsorption capacity of the 80-100 cm subsoils at a solution P concentration of0.5 mg L^(-1) was 15.7(S5),8.7(S15),and 6.5(S30)kg ha^(-1),demonstrating that subsoils were unable to secure P concentrations in leaching water below 0.5 mg L^(-1) because of their insufficient P-binding capacity.

关键词： greenhouse vegetable production Langmuir model P adsorption capacity P desorption P immobilization P mobility subsoil topsoil

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Vertical Distribution of Soil Pyrogenic Matter: A Review

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Pedosphere 2019年第2期29卷 137-149页

作者： Eleanor HOBLEY Soil Science Technical University of Munich

Alteration of terrestrial biomass during fire produces pyrogenic matter, a large quantity of which is deposited on and may enter soils. The amount of annual burning around the globe implies greater production and storage of carbon in soil pyrogenic organic matter(pyrOM) than is regularly found in investigations of soil pyrogenic matter. A portion of this unaccounted for pyrogenic material may be translocated to subsurface soil depths, which is frequently excluded from soil investigations, and the presence of subsoil charcoal helps to partially fill this pyrOM gap. In this paper, I discuss the mechanisms for vertical redistribution of pyrogenic matter in soils and develop conceptual models to describe the depth, particle size, and age distribution of pyrogenic matter resulting from different translocation mechanisms. Based on the relationships between pyrogenic matter turnover and translocation, the suitability of pyrogenic matter in soils as an indicator for soil processes is discussed. Deciphering the relationships between pyrogenic matter depth, particle size, and age distribution yields valuable insights into the dynamics of soil forming processes as well as soil pyrogenic matter turnover,which should therefore, be a focus of future studies.

关键词： age black carbon charcoal mobility organic matter particle size subsoil translocation

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Soil Organic Matter Composition in Coastal and Continental Date Palm Systems: Insights from Tunisian Oases

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Pedosphere 2019年第4期29卷 444-456页

作者： Rawan K. MLIH Martina I. GOCKE Roland BOL Anne E. BERNS Irabella FUHRMANN Nadhem BRAHIM Institute of Crop Science and Resource Conservation University of Bonn Bonn 53115 (Germany) Agrosphere Institute (IBG-3) Forschungszentrum Julich GmbH Julich 52428 (Germany) Department of Geology University of Tunis El Manar Tunis 2092 (Tunisia)

In Tunisia, the coastal Chenini oasis is characterized by a lush vegetation cover, whereas more inland continental oases(e.g., the Guettaya oasis) have a very scarce vegetation cover. For sustaining date palm production in these areas, organic fertilizers are applied,either spread on the soil surface(in Chenini) or buried under a sand layer(in Guettaya). We examined at a molecular level how these management techniques affect soil organic matter composition in oasis systems. A dominance of fresh plant input for Guettaya was indicated by solid-state 13C nuclear magnetic resonance spectroscopy signals, which was most pronounced in the uppermost soil close to palms. Evidence for more degraded organic matter was found in deeper soil near the palms, as well as in the soil distant from the palms. Amino sugar contents were low in the uppermost Guettaya soil near the palms. The overall microbial amino sugar residue contents were similar in range as those found in other dryland environments. With increasing distance from trees, the amino sugar contents declined in Guettaya, where the palms grow on bare soil, but this was not the case for Chenini, which has multi-layer vegetation cover under palms. In agreement with the results from previous dryland studies, the soil microbial community in both oasis systems was dominated by fungi in topsoil, and a shift toward bacteria-derived residues in subsurface soil. This might be due to higher variability of temperature and moisture in topsoil and/or lower degradability of fungal remains;however, further research is required to confirm this hypothesis.

关键词： amino sugar dryland microbial community soil organic carbon solid-state NMR subsoil amelioration total nitrogen

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Key aspects on the behaviour of the ballast and substructure of a modern railway track:research-based practical observations in Finland

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第11期13卷 825-835页

作者： Antti NURMIKOLU Department of Civil Engineering Tampere University of TechnologyTampereFinland

This paper presents an overview on the wide-ranging track structure studies at the Tampere University of Technology(TUT),Finland dealing with the key aspects of track geotechnics related to high-speed passenger traffic on ballasted *** attention is paid to ballast and sub-ballast,while also considering frost action,embankment stability,track stiffness,track geometry and transition *** a result,this paper states that understanding the ballast degradation mechanism and its consequences and assessment of its condition occupy an important role in the construction and maintenance of a smooth high-speed rail *** choices related to building the sub-ballast also have a dramatic impact on later track deformations and maintenance *** cold climate,especially where seasonal frost occurs,understanding and taking into account the frost action mechanism is *** in the maintenance and rehabilitation planning of existing tracks,high-class analyses of ground penetrating radar data and its integrated analysis with other data can yield considerable benefits.

关键词： Railway Track Ballast Sub-ballast Substructure subsoil Frost action Life cycle Ground penetrating radar

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Prediction of the P-leaching potential of arable soils in areas with high livestock densities

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第7期7卷 515-520页

作者： WERNER Wilfried TRIMBORN Manfred PIHL Uwe Institute for Plant Nutrition University of Bonn D-531159 Bonn Germany

Due to long-term positive P-balances many surface soils in areas with high livestock density in Germany are over-supplied with available P, creating a potential for vertical P losses by leaching. In extensive studies to characterize the endangering of ground water to P pollution by chemical soil parameters it is shown that the available P content and the P concentration of the soil solution in the deeper soil layers, as indicators of the P-leaching potential, cannot be satisfactorily predicted from the available P content of the topsoils. The P equilibrium concentration in the soil solution directly above ground water table or the pipe drainage system highly depends on the relative saturation of the P-sorption capacity in this layer. A saturation index of <20% normally corresponds with P equilibrium concentrations of <0.2 mg P/L. Phytoremediation may reduce the P leaching potential of P-enriched soils only over a very long period.

关键词： P-balance P-accumulation P-saturation index subsoil P equilibrium concentration Phytoremediation

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Soil health and microbial network analysis in a wheat-maize croppingsystem under different wheatyields

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Frontiers of Agricultural Science and Engineering 2024年第4期11卷 615-625页

作者： Xinzhan SUN Tengteng LI Jiangzhou ZHANG State Key Laboratory of Nutrient Use and Management Key Laboratory of Plant-Soil Interactions(Ministry of Education)College of Resources and Environmental SciencesNational Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Key Laboratory of Agricultural Ecological Security and Green Development Inner Mongolia Key Laboratory of Soil Quality and Nutrient ResourcesCollege of Resources and Environmental SciencesInner Mongolia Agricultural UniversityHohhot010018China

Healthy soil is crucial for sustainable agriculture with soil microbiomes being key to soil ***,comprehensive assessments of soil health and microbial community structures under different wheat yields have not been ***,soil samples were collected from wheat fields with differing yields at depths of 0-15 and 15-30 *** yields were categorized as low(Y1,3.75t·ha^(-1)),medium(Y2,6.00 t·ha^(-1)),high(Y3,8.25 t·ha^(-1)),and maximum(Y4,1o.1 t·ha^(-1)),and soil health and microbial communities *** results showed that both yield category and soil depth significantly influenced SOC,TN,mineral nitrogen,AP and AK,enzyme activity,and soil bacterial *** soil health index in Y4(0.51-0.87)was significantly higher than in Y3(0.39-0.63),Y2(0.27-0.45),and Y1(0.21-0.52)at both 0-15 and 15-30 cm(expect Y1).Significant correlation was only found between soil health index at 0-15 cm and wheat yield,not at 15-30 *** bacterial and fungal network structure in Y4 was more complex and densely ***,Thaumarchaeota,and Ascomycota were identified as key drivers of soil *** on these results,the regulation of microbes has the potential to improve soil health and crop yields.

关键词： Soil health index soil microbial network subsoil topsoil yieldcategories

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