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Constraints of authigenic carbonates on trace elements (Sr,Mg) of lacustrine ostracod shells in paleoenviron-ment reconstruction and its mechanism

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science china Earth sciences 2008年第5期51卷 654-664页

作者： HU Guang1,2, JIN ZhangDong1 & ZHANG Fei3 1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of sciences, Xi’an 710075, china 2 Graduate university of the Chinese Academy of sciences, Beijing 100049, china 3 college of resources and environmental science, nanjing agricultural university, nanjing 210095, china State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China Graduate university of the Chinese Academy of sciences Beijing China college of resources and environmental science Nanjing Agricultural University Nanjing China

Molar ratios of Mg/Ca and Sr/Ca were measured in two species of ostracod shells preserved in the upper core (15–55 m) of the Hequing Basin in Yunnan Province, southwest china. By correlating the molar ratios between Mg/Ca and Sr/Ca and comparing them with Sr concentrations of the sediments, we suggested that: (1) the molar Mg/Ca and Sr/Ca ratio variations in respective ostracod primo reflected the changes in its ambient water composition and ecology; (2) the molar Sr/Ca ratios responded better to the salinity change linearly than Mg/Ca without aragonite precipitation in the system, and otherwise there was no linear relation between them; and (3) the molar Sr/Ca ratios were mainly controlled by salinity and authigenic carbonate precipitation, whereas the molar Mg/Ca ratios were related to both salinity and temperature. In fact, the rate of ostracod growth owing to temperature controls the fluctuation of Mg/Ca in shells. Here, more attentions should be paid to the constraint of authigenic mineral precipitation processes on the trace elements in ostracod shells and to the correlation between these trace elements in biogenic carbonates and compositions of the sediments in systems and in future in vitro experiments.

关键词： ostracod shell molar Sr/Ca ratio molar Mg/Ca ratio environmental response Heqing Basin

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半干旱地区海水灌溉下滨海盐土盐分运动研究

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土壤学报 2004年第5期41卷 823-826页

作者：刘兆普陈铭达刘玲邓力群赵耕毛王洪军王建华南京农业大学资源与环境科学学院南京210095 南京市建邺区科学技术局南京210097 南京农业大学863山东莱州中试基地山东莱州261400

海水灌溉农业是国际范围内新兴的热点研究领域.在我国海水灌溉农业研究还刚刚起步.为探索海水灌溉对滨海盐土发育演变的影响,作者从2000年起,在半干旱的山东莱州地区进行海水灌溉下滨海盐土水盐运动的田间试验研究,以率定不同气候带土... 详细信息

海水灌溉农业是国际范围内新兴的热点研究领域.在我国海水灌溉农业研究还刚刚起步.为探索海水灌溉对滨海盐土发育演变的影响,作者从2000年起,在半干旱的山东莱州地区进行海水灌溉下滨海盐土水盐运动的田间试验研究,以率定不同气候带土壤发育安全的海水灌溉指标与参数,探索可行的土壤水盐调控技术体系,并根据田间试验结果安排原状土柱室内模拟试验,以深入探讨其作用机制.本文仅就田间盐分运动试验结果进行讨论.

关键词：半干旱地区海水灌溉滨海盐土盐分运动

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Cadmium transport mediated by soil colloid and dissolved organic matter:A field study

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Journal of environmental sciences 2010年第1期22卷 106-115页

作者： Zhaoli Li, Lixiang Zhou college of resources and environmental sciences, nanjing agricultural university, nanjing 210095, china. college of resources and environmental sciences Nanjing Agricultural University Nanjing 210095 Chin

This study investigated the potential role of soil colloids and dissolved organic matter （DOM） in transporting Cd through in situ undisturbed paddy soil monoliths. Brilliant Blue was used as a tracer to assess the effect of preferential flow on Cd down migration. Experimental results showed that deep penetration of Cd and Brilliant Blue into the soil profile took place due to the preferential flow through macropores, mainly earthworm channels, with much of chemicals thus bypassing the soil matrix. Dye tracer and Cd distribution within the soil matrix was fairly restricted to several centimeters. Colloid restrained the migration of both dye and Cd in the matrix and preferential flow area. DOM facilitated the transport of Cd and Brilliant Blue in matrix and macropores by about 10 cm over that of the control. Pearson＇s is correlation analysis revealed strong associations between Brilliant Blue concentrations, exchangeable Cd and total Cd concentrations in three studied plots indicating that they had taken the same preferential flow pathway.

关键词： colloid dissolved organic matter preferential flow dye tracer

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Effect of biosurfactant on the sorption of phenanthrene onto original and H_2O_2-treated soils

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Journal of environmental sciences 2009年第10期21卷 1378-1385页

作者： PEI Xiaohong, ZHAN Xinhua, ZHOU Lixiang college of resources and environmental sciences, nanjing agricultural university, nanjing 210095, china. college of resources and environmental sciences Nanjing Agricultural University

The objective of this study was to examine the effect of biosurfactant on the sorption of phenanthrene （PHE） onto the original or HzO2-treated black loamy soil （typic isohumisols） and red sandy soil （typic ferralisols）. The sorption isotherms were performed with the original and ＂soft＂ carbon-removed soils in the presence and absence of biosurfactant （200 mg/L）. The sorption and degradation of biosurfactant were investigated. The result showed that organic matter played an important role in PHE sorption onto the black loamy and red sandy soils, and the PHE sorption isotherms on the ＂soft＂ carbon-removed soils exhibited more nonlinearity than those on the original soils. The values of partition coefficient （Kd） on the original black loamy soil with or without 200 mg/L biosurfactant were 181.6 and 494.5 mL/g, respectively. Correspondingly, in the red sandy soil, Kd was 246.4 and 212.8 mL/g in the presence or absence of biosurfactant, respectively. The changes of Kd suggested that biosurfactant inhibited PHE sorption onto the black loamy soil, but facilitated PHE sorption onto the red sandy soil. The nonlinearity of PHE sorption isotherm was decreased in the presence of biosurfactant. Site specific sorption might occur during PHE sorption onto both the original and the ＂soft＂ carbon-removed soils in the presence of biosurfactant. It was noted that biosurfactant could also be sorbed onto soils. The maximal sorption capacity of the red sandy soil for biosurfactant was （76.9 ± 0.007） μg/g, which was 1.31 times that of black loamy soil. Biosurfactant was degraded quickly in the two selected soils, and 92% of biosurfactant were mineralized throughout the incubation experiment for 7 d. It implied that biosurfactant should be added frequently when the remediation of polycyclic aromatic hydrocarbon （PAH）-contaminated soils was conducted through PAH desorption approach facilitated by biosurfactant.

关键词： biosurfactant phenanthrene sorption "soft" carbon soil

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Alkaloid Accumulation in Catharanthus roseus Increases with Addition of Seawater Salts to the Nutrient Solution

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Pedosphere 2010年第6期20卷 718-724页

作者： WANG Jing-Yan and LIU Zhao-Pu college of resources and environmental sciences,nanjing agricultural university,nanjing 210095 (china) nanjing Agr Univ Coll Resources and Environm Sci Nanjing 210095 Peoples R China

A sand culture experiment was conducted to determine the effects of different seawater (5% and 10%) treatments on plant growth,inorganic ions,indole alkaloid concentrations and yields of Catharanthus roseus,in an effort to increase the alkaloid yield by artificial *** total fresh and dry weights and tissue K + concentrations decreased,but Na + concentrations increased in the plant roots,stems and leaves of *** under seawater stress as compared to the *** concentrations and yields of vindoline,catharanthine,vinblastine and vincristine increased under seawater *** concentrations and yields of these alkaloids were higher in 5% seawater-treated plants than those in the 10% seawater-treated *** the industrial production,5% seawater treatments could reduce the cost of producing *** the control plants,the highest alkaloid concentrations reached a peak at 100 days after planting,suggesting that plant harvest must be optimized in terms of growth duration.

关键词： indole alkaloid inorganic ions plant growth seawater irrigation seawater stress

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Genotypic Differences in Grain Yield and Physiological Nitrogen Use Efficiency Among Rice Cultivars

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Pedosphere 2009年第6期19卷 681-691页

作者： ZHANG Ya-Li, FAN Jian-Bo, WANG Dong-Sheng and SHEN Qi-Rong2college of resources and environmental sciences, nanjing agricultural university, nanjing 210095 (china) college of resources and environmental sciences Nanjing Agricultural University Nanjing 210095 (China)

Efficient use of N in agricultural practice can increase yield, decrease production costs and reduce the risk of environmental pollution. Effects of N fertilizer application rates on grain yield and physiological N use efficiency (PE) in relation to the accumulation and redistribution of biomass and N in rice (Oryza sativa L.) cultivars were studied at two experimental farms of nanjing agricultural university, nanjing, china in 2004. Three high N use efficiency (NUE) rice cultivars (Wuyunjing 7, Nanguang and 4007) and one low NUE rice cultivar (Elio) with similar growth patterns were studied under seven N rates (0, 60, 120, 180, 240, 300 and 360 kg ha -1 ). Grain yield increased with the N application rate and attained plateau at 180 kg N ha -1 for rice cultivars at each site. Increasing N rate decreased PE for biomass and grain yield. Grain yield and PE of Elio were about 20% and 18% lower than those of high NUE cultivars. Differences in biomass, N accumulation and N redistribution were observed at the post-heading stage among rice cultivars with differing NUEs. The less reproductive tillers of Elio resulted in less demand for C and N during grain filling, thus leading to lower PE of Elio compared with the high NUE rice cultivars.

关键词： accumulation biomass N application rate redistribution

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Nitrification Potential of Soils Under Liquid Incubation Conditions

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Pedosphere 2005年第3期15卷 379-385页

作者： YUANFei RANWei SHENQi-Rong collegeofresourcesandenvironmentalsciences NanjingAgriculturalUniversityNanjing210095（China）

A red soil, a fluvo-aquic soil and a permeable paddy soil were used in a long-term investigation to study changes in nitrification with treatments: 1) soil incubation, 2) liquid incubation inoculated with soil samples, and 3) liquid incubation inoculated with ammonia-oxidizing bacteria (AOB) from the soils. There were significant differences (P < 0.001) in nitrification rates among the three soils when measured for 28 days by adding (NH4)SO4 at the rate of 154 mg N kg-1 dry soil to fresh soil. However, t…

关键词： ammonia-oxidizing bacteria nitrification pH soil type

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Effect of Silicon on Leaf Ultrastructure, Chlorophyll Content and Photosynthetic Activity of Barley Under Salt Stress

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Pedosphere 1998年第4期8卷 289-296页

作者： LIANG YONGCHAO (Department of Plant Nutrition, college of Natural Reaources and environmental science, and Ministry of Agriculture Key Laboratory of Crop Growth and Regulation, nanjing agricultural university, nanjing 210095 china) Department of Plant Nutrition College of Natural Resources and Environmental Science Nanjing Agricultural University Nanjing 210095 China

Two contrasting cultivars of barley (Horderm vykgare L.): Kepin No. 7 (salt sensitive), and Jian 4 (salt tolerant) were grown in a hydroponics system with 2 NaCl levels: 60 mmol NaCl L-1 and 120 mmol NaCl L-1, and 3 Si levels: 0 mmol Si L-1, 0.5 mmol Si L-1 and 1.0 mmol Si L-1 (as silicic acid). Compared with the plants treated with 60 mmol NaCl L-1 alone, the leaf chlorophyll contents of plants treated with salt and Si increased significantly for salt-sensitive cultivar at tillering stage, but for salt-tolerant cultivar,the addition of Si resulted in an obvious increase in the leaf chlorophyll content of plants exposed to 120 mmol NaCl L-1. However, this Si-enhancement of leaf chlorophyll content was also observed in the salttolerant plants at jointing stage, but not in the salt-sensitive plants. Moreover, leaf chlorophyll content was consistently higher for the salt-tolerant cultivar than for the salt-sensitive cultivar irrespective of salt and/or Si treatment. Compared with the plants treated with salt alone, net CO2 assimilation rate in plant leaves increased significantly for both cultivars when trested with salt and Si. The addition of Si to the salt treatment was found to improve the cell ultrastructure of leaves. Under salt stress condition, the double membranes of chloroplasts disappeared, but membrane integrity was markedly improved in the salt treatment supplemented with Si. Silicon was also found to ameliorate the damage to the ultrastructure of chloroplast granae which appeared to be disintegrated and vague in salt treatments without added Si. The results support previous work which showed that Si decreases the permeability of plasma membranes of salt-stressed barley, thus mitigating salt damage.

关键词： barley photosynthesis salt silicon ultrastructure

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Effect of Bacterial-Feeding Nematode Inoculation on Wheat Growth and N and P Uptake

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Pedosphere 2001年第1期11卷 57-62页

作者： LIHULXIN HUFENG collegeofresourcesandenvironmentalsciencesandInstituteofAgiculturalresourcesandEco－environment NanjingAgriculturalUniversityNanjing210095（China） collegeofresourcesandenvironmentalsciencesandInstitute

A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp. stimulated the growth of wheat (Triticum aestivum) and the uptake of N. By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.) increased by 6.5% and 5.9%, respectively, compared with bacteria alone treatment. The presence of nematode mainly accelerated the growth of aboveground of wheat, while it slightly inhibited the root development. There was little difference in plant tissue N concentration between treatments. P concentration and uptake of wheat, however, were generally reduced by nematode. It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineralization induced by nematode feeding on bacteria, and the reduction of phosphorous uptake is the result of weak root status and competition by bacteria immobilization.

关键词： bacterial-feeding nematode nematode-bacteria interaction nitrogen and phosphorous uptake wheat growth

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Interactive effect of dissolved organic matter and phenanthrene on soil enzymatic activities

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Journal of environmental sciences 2010年第4期22卷 607-614页

作者： Xinhua Zhan,Wenzhu Wu,Lixiang Zhou,Jianru Liang,Tinghui Jiang college of resources and environmental sciences,nanjing agricultural university,nanjing 210095,china.Greenstar Plant Products Inc.,9430 198 St,Langley,BC,Canada V1M3C8. college of resources and environmental sciences Nanjing Agricultural University Nanjing 210095 Chin

The investigation of dissolved organic matter （DOM） on urease, catalase and polyphenol oxidase activity in a phenanthrene （Phe）- contaminated soil was conducted under laboratory incubation conditions. Values of soil enzymatic activity depended mainly on incubation time. In the initial 16 days, urease activity increased, and was followed by a decrease. In the initial 8 days, catalase activity decreased and then increased. Variation of polyphenol oxidase activity was just the reverse of catalase activity. After 30 days of incubation, no pronounced difference among treatments with Phe, Phe and DOM, and control were detected in urease, catalase and polyphenol oxidase activity. Phe might inhibit urease and catalase, and stimulate polyphenol oxidase. DOM could improve inhibition of Phe in soil urease and catalase activity during the initial period of applying DOM. Nevertheless, DOM had no significant effect on polyphenol oxidase activity in the Phe contaminated soil. There was a negative correlation between catalase and polyphenol oxidase （r = -0.761＊＊＊）, and catalase and urease （r = -0.554＊＊）. Additionally, a positive correlation between polyphenol oxidase and urease was also detected （r = 0.701＊＊＊）. It is implied that the formed DOM after application of organic wastes into soils may counteract the inhibition of polycyclic aromatic hydrocarbons in soil enzyme activities.

关键词： polycyclic aromatic hydrocarbons dissolved organic matter phenanthrene soil enzymes

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