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Phosphorus Concentration and Forms in Surface and Subsurface Drainage Water from Wetland Rice Fields in the Shaoxing Plain

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Pedosphere 2003年第3期13卷 239-248页

作者： ZHANG MINGKUI, JIANG HONG and LIU XINGMEIDepartment of resource sciences, college of resource and environmental sciences, zhejiang university, hangzhou 310029 (china) Department of resource sciences College of Resource and Environmental Sciences Zhejiang UniversityHangzhou 310029 China

Phosphorus (P) is the limiting factor for eutrophication in most freshwater ecosystems. In china, Ptransported from intensively cultivated land has been reported as an important source of P in surface *** this study, we investigated P concentration and forms in surface and subsurface drainage from wetland ricefields in the Shaoxing plain, zhejiang Province, china. From selected rice fields, surface drainage sampleswere collected at rice-growing, non-growing and fertilization periods, and subsurface drainage samples atdrought and rewetting (irrigation or precipitation after 5～10 d drought period in the surface soils) and wet(drainage under long-term wet soil condition) periods. Water samples were characterized for their totalreactive P (TRP), dissolved reactive P (DRP) and particulate reactive P (PRP). Concentrations of the TRPand DRP in the surface drainage ranged from 0.08 to 1.50 and 0.06 to 1.27 mg L-1, respectively. The TRPand DRP were dependent on field operation activities, and decreased in the order of fertilization period ＞rice-growing period ＞ non-growing period. Phosphorus concentration of runoff receiving P fertilizer can bean environmental concern. The PRP concentration in the surface drainage, ranging from 0.01 to 0.57 mgL-1, accounted for 8%～78% of the TRP. Concentration of the TRP in the subsurface drainage was from0.026 to 0.090 mg L-1, consisting of 29%～90 % of the DRP and 10%～71% of the PRP. In the droughtand rewetting period, the PRP accounted for, on average, 63% of the TRP, much higher than in the wetperiod (23%), suggesting that there was transport of P in preferential flow during drainage events after ashort-term drought period in the surface soils. Therefore, P losses in particulate form may be importantin the subsurface drainage from rice fields when surface soils form cracks and favor rapid flow downwardthrough the soil profiles, suggesting the important role of water-dispersible colloid particles in mediating andco-transporting P in

关键词： drainage phosphorus wetland rice field

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Occurrence of nitrification-denitrification and gaseous nitrogen loss process in flooded rice soil

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Progress in Natural Science:Materials International 2007年第1期17卷 6-10页

作者： NI Wuzhong, LI Jianping and ZHU Zhaoliang (college of environmental and resource sciences, zhejiang university, hangzhou 310029, china college of Biosystems Engineering and Food Science, zhejiang university, hangzhou 310029, china Institute of Soil Science, Chinese Academy of sciences, Nanjing 210008, china) [a]Gllege of environmental and Resmirce sciences Zheiang University Hangzhou China [b]Gllege of Biosystems Engineering and Food Science Zheiang University Hangzhou China [c]Institute of Soil Science Chinese Academy of Sciences Naning China

Flooding in wetland rice fields soon after transplanting results in displacement of soil air (including O2). Thus any dissolved O2 in the pore water is consumed out by microbial respiration in a short period. Supply of O2 to the flooded rice soil is by diffusion of O2 through the standing floodwater and consumption at the soil-water interface, and by exudation of O2 by rice roots and subsequent diffusion of O2 into the rhizosphere. The greater potential consumption of O2 compared to the renewal rate results in the development of distinct soil layers: oxidized soil layers under soil-water interface and in the rhizosphere, and reduced soil layers or reduced bulk soil. Nitrification in oxidized soils and denitrification in reduced soils have been known. Currently, denitrification in oxidized soils, even in standing floodwater, has also been identified. In this article, we present a modified nitrification and denitrification occurring mechanism in flooded rice soil.

关键词： denitrification flooded rice soil gaseous nitrogen loss nitrification.

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Understanding the endocrine disruption of chiral pesticides:The enantioselectivity in estrogenic activity of synthetic pyrethroids

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Science china Chemistry 2010年第5期53卷 1003-1009页

作者： WANG Cui 1,ZHANG Quan 1,ZHANG XiaoFeng 1,LIU Jing 2 & LIU WeiPing 2 1college of Biological and environmental Engineering,zhejiang university of Technology,hangzhou 310032,china 2Key Laboratory of environmental Remediation and Ecosystem Health,Ministry of Education college of environmental and resource sciences,zhejiang university,hangzhou 310029,china 1. college of Biological and environmental Engineering Zhejiang University of Technology Hangzhou 310032 China2. Key Laboratory of Environmental Remediation and Ecosystem Health Ministry of Education College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 China

Synthetic pyrethroids(SPs) ,a family of chiral insecticides consisting of multiple stereoismers,have been regarded as estrogenic endocrine-disrupting chemicals(EDCs) .In this study,we applied the yeast two-hybrid and molecular docking(MD) assay to assess the enantioselective estrogenic activities of three commonly used SPs,bifenthrin(cis-BF) ,permethrin(PM) and fenvalerate(Fen) .The β-galactosidase analyses indicated that all of the testing pyrethroids displayed significant(p<0.05) *** results showed that the estrogenic potential of cis-BF was mainly attributed to *** PM nor Fen showed estrogenic ***,two stereoisomers of PM possessed estrogenic potential activities.αR-2R-Fen and αS-2S-Fen also induced the β-galactosidase *** inability to initiate the reporter gene expression by the racemic chemicals may be due to the low ratios of these isomers or the antagonism among *** strong hydrophobic interaction and the hydrogen bond between positive estrogenic isomers and ERα support our biological testing *** research demonstrated that the enantioselective estrogenic activity of chiral SPs was due to selective binding between their isomers and the ERα*** data suggests that enantioselectivity of these chiral pesticides is significant to their estrogenic activities.

关键词： enantioselectivity synthetic pyrethroids (SPs) endocrine disruption yeast molecular docking

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Calibration of KEC Value in Acidic Red Soils with Fumigation-Extraction Method

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Pedosphere 2002年第1期12卷 33-40页

作者： CHEN GUOCHAO and HE ZHENLI Department of resource Science, college of environmental and resource sciences, Huajiachi Campus, zhejiang university, hangzhou 310029 (china) Department of resource Science College of Environmental and Resource Sciences Huajiachi Campus Zhejiang University Hangzhou 310029

Commonly used KEC value (0.45) of the fumigation-extraction (FE) method was obtained on the basis of temperate neutral soils. To ascertain its applicability to acidic red soils widespread in southern china and other subtropical regions, the KEC value was investigated based on 8 acidic red soils by in situ labelling of native soil microorganisms using 14C-labelled glucose. Realistic KEC value for red soils could be obtained by in situ 14C-labelling as long as an incubation period of 72 h is adopted after addition of 14C glucose to soil. The single KEC values for the eight red soils ranged from 0.27 to 0.35 and averaged 0.31. Lower KEC value obtained in red soils probably resulted from different soil quality, compared with other types of soil, which causes possible changes in microbial community structure and extractability of cellular component. Microbial biomass C contents of the eight red soils measured using a unique and constant KEC value of 0.45 decreased by 22.2%~40% in comparison to those usin g variable KEC values. The results suggest that microbial biomass C would be significantly underestimated using the present KEC value and a calibration of the KEC value is necessary for red soils.

关键词： calibration in situ 14C-labelling KEC value red soils

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Sodium and Potassium Absorption and Distribution in Relation to Growth and Internal Potassium Use Efficiency of K-efficient and -inefficient rice genotypes

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Pedosphere 2001年第3期11卷 235-242页

作者： LIU JIANXIANG YANG XIAOE NI WUZHONG and YANG YUAI college of environmental and resource sciences, zhejiang university, hangzhou, 310029 (china) 浙江大学浙江杭州 310029

A pot experiment with two rice (Oriza sativa L.) genotypes differing in internal potassium use efficiency (IKUE) was conducted under different sodium (Na) and potassium (K) levels. Adding NaCl at a proper level enhanced rice vegetative growth and increased grain yield and IKUE under low potassium. Addition of higher rate of NaCl had a negative effect on the growth of the K-efficient rice genotype, but did not for the K-inefficient genotype. Under low-K stress, higher NaCl decreased IKUE of the K-efficient rice genotype but increased IKUE for the K-inefficient genotype. At tillering stage and under low-K stress, adding NaCl increased K and Na contents and decreased the ratio of K/Na for both genotypes. At harvesting stage under low-K stress, adding NaCl increased K and Na contents and K/Na ratio for the K-efficient genotype but decreased the K/Na ratio for the K-inefficient genotype. The accumulated Na was mostly deposited in the roots and sheaths. At tillering stage, the K and Na contents and the K/Na ratios in different parts for both genotypes decreased in the following sequence: K+ in sheaths > K+ in blades > K+ in roots; Na+ in roots > Na+ in sheaths > Na+ in blades; and K/Na in sheaths 》 K/Na in roots. The K-efficient genotype had a lower K/Na ratio in roots and sheaths than the K-inefficient genotype under low-K stress. At harvesting stage, K and Na contents in grains were not affected, whereas K/Na ratio in the rice straws was increased for the K-efficient genotype but decreased for the K-inefficient genotype by Na addition. However, this was not the case under K sufficient condition.

关键词： distribution internal K use efficiency (IKUE) K Na rice genotypes

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Cadmium Release in Contaminated Soils due to Organic Acids

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Pedosphere 2004年第2期14卷 223-228页

作者： LIAOMin XIEXiao-Mei DepartmentofresourcesScience CollegeofEnvironmentalandResourceSciencesZhejiangUniversityHangzhou310029（China）.E-mail：liaomin@***

There is limited information on the release behavior of heavy metals fromnatural soils by organic acids. Thus, cadmium release, due to two organic acids (tartrate andcitrate) that are common in the rhizosphere, from soils polluted by metal smeltersor tailings andsoils artificially contaminated by adding Cd were analyzed. The presence of tartrate or citrate at alow concentration (= 2 mmol L^(-1) for citrateand >= 15 mmol L^(-1) for tartrate) apparently promoted Cd release. Under the same conditions, theCd release in naturally polluted soils was less than that of artificially ***, as the initial pH rose from 2 to 8 in the presence of citrate, a sequentialvalley and then peak appeared in the Cd release curve, while in the presence of tartrate the Cdrelease steadily decreased. In addition, Cd release was clearly enhanced as the electrolyteconcentration of KNO_3 or KC1 increased in the presence of 2 mmol L^(-1) tartrate. Moreover, ahigher desorption of Cd was shown with the KCl electrolyte compared to KNO_3 for the sameconcentration levels. This implied that the bioavailability of heavy metals could be promoted withthe addition of suitable types and concentrations of organic acids as well as reasonable fieldconditions.

关键词： artificially contaminated soil cadmium organic acid polluted soil release

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Heavy Metals, Phosphorus and Some Other Elements in Urban Soils of hangzhou City, china

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Pedosphere 2004年第2期14卷 177-185页

作者： ZHANGMing-Kui KEZi-Xia DepartmentofNaturalresourceScience CollegeofNaturalResourceandEnvironmentalSciencesZhefiangUniversityHangzhou310029（China）.E-mail：mkzhang@***

Health implications of inhaling and/or ingesting dust particles with high concentrations of heavy metals from urban soils are a subject of intense concern. Understanding the geochemistry of these metals is key to their effective management. Total concentrations of heavy metals,phosphorus (P) and 8 other elements from topsoil samples collected at 82 locations in hangzhou City were measured to:a) assess their distribution in urban environments; and b) understand their differentiation as related to land use. Metal mobility was also studied using a three-step sequential chemical fractionation procedure. About 8.5%,1.2%,3.6%,11.0% and 30.3% of the soil samples had Cd,Cr,Cu,Pb,and Zn concentrations,respectively,above their allowable limits for public and private green areas and residential use. However,in commercial and industrial areas,most samples had metal concentrations below their allowable limits. Statistical analyses revealed that the 16 measured elements in urban soils could be divided into four groups based on natural or anthropic sources using a hierarchical cluster analysis. Additionally,Cu,Pb,and P showed similar spatial distributions with significant pollution in commercial zones,suggesting vehicle traffic or commercial activities as dominant pollutant sources. Also,Cd,Co,Cr,Ni,Zn,Mn and Fe had the highest concentrations in industrial locations,signifying that industrial activities were the main sources of these seven metals. Moreover,the data highlighted land-use as a major influence on heavy metal concentrations and forms found in topsoils with large proportions of soil Cd,Co,Cr,and Ni found in residual fractions and soil Cu,Pb and Zn mainly as extractable fractions.

关键词： anthropogenic pollution heavy metals phosphorus urban soils

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Effect of Reduction Associated with Organic Matter Decomposition on Magnetic Properties of Red Soils

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Pedosphere 2003年第2期13卷 103-110页

作者： DONGRUIBIN ZHANGWEIGUO LUSHENGGAO YULIZHONG YUJINYAN Departmentofenvironmentalengineering NanchangUniversityNanchang330029(China) StateKeyLaboratoryofEstuarine&CoastalResearch EastChinaNormalUniversityShanghai200062(China) collegeofenvironmentalandresourcesciences zhejiangUniversityHangzhou310029(China)

Five soils derived from different parent materials were sampled from red soilregion of southern china and studied by magnetic methodology to understand to what extent ironreduction would affect soil magnetic properties and how iron reduction would affect the magneticminerals in soils. Reduction associated with organic matter decomposition strongly affected soilmagnetic parameters at low pH. The losses of original soil magnetic signals in terms of magneticsusceptibility (X), 'Soft' isothermal remanent magnetization ('Soft' IRM), anhysteretic remanentmagnetization (ARM) and saturation isothermal remanent magnetization (SIRM) at pH 4～6 during thetwo-month saturation treatment, were 66%～94%, 54%～90%, 64%～95% and 33%～83%, respectively. Thesechanges were interpreted as a consequence of substantial dissolution of maghaemite and haematite inthe soils. At pH 10, however, there was no significant magnetic change observed. Moreover, stablesingle domain soil maghaemite grains were also sensitive to reduction, which suggested that bothpedogenic and detrital maghaemite were not stable in acid and reducing environments. Goethite,instead, was the most stable iron form under reducing conditions.

关键词： goethite haematite maghaemite magnetic susceptibility reduction

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Characterization of Nitrogen Metabolism in the Low-Nitrogen Tolerant lnt1 Mutant of Arabidopsis thaliana Under Nitrogen Stress

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Pedosphere 2010年第5期20卷 623-632页

作者： TENG Yi-Bo LI Ya-Juan FANG Ping LA Gui-Xiao Ministry of Education Key Laboratory of environmental Remediation and Ecological Health College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 (China) zhejiang Provincial Key Laboratory of Subtropical Soil Science and Plant Nutrition College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 (China)

A growth experiment on agar medium and a hydroponics experiment were carried out to study the nitrogen （N） metabolism of a low-N tolerant mutant （lntl） of Arabidopsis thaliana under different N levels as compared with the wild- type （WT） Arabidopsis. On the agar medium, no apparent growth differences were observed between the lntl and WT plants under a normal N level of 9 mmol L^-1 NO3. However, under a low N level of 0.18 mmol L^-1 NO3^-, the growth of the WT plants was greatly retarded, while the lntl plants were not affected by low-N stress and showed similar growth with those grown under a normal N level. In the hydroponics experiment, the lntl mutant had higher activities of glutamine synthetase （GS） and NADH-dependent glutamate synthase （NADH-GOGAT） in both leaves and roots under N-deficient conditions. Moreover, they accumulated less ammonium （NH4^＋） but more free amino acids in leaves compared with the WT plants. These observations suggest that better N assimilation might contribute to the low-N tolerant phenotype of the lnt1 mutant.

关键词： ammonium free amino acids glutamate synthase glutamine synthetase nitrogen assimilation

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Phytoremediation of Rocky Slope Surfaces: Selection and Growth of Pioneer Climbing Plants

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Pedosphere 2009年第4期19卷 541-544页

作者： WANG Zhong-Qiang WU Liang-Huan S. ANIMESH ZHU Yuan-Hong Ministry of Education Key Lab of environmental Remediation and Ecosystem Health College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 （China） college of Urban and environmental sciences Northeast Normal University Changchun 130024 （China） zhejiang Provincial Key Laboratory of Subtropical Soil and Plant Nutrition College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 （China） Department of Crop and Soil sciences The Pennsylvania State University University Park PA 16802 （USA）

INTRODUCTION As a result of the massive construction following rapid economic growth in china, extraction of building materials from mountain resources has left behind many quarries. Those quarries usually have rocky surfaces and steep slopes. The existence of rocky slopes is not only a safety hazard but also increases soil erosion and affects landscape aesthetics. Natural restoration of vegetation on rocky slope surfaces is a very slow process, which might require hundreds of years, and is not considered an acceptable restoration strategy （Cullen et al., 1998）. Phytoremediation methods have been widely considered as a better option for vegetation establishment on rocky slope surfaces （Muzzi et al., 1997）.

关键词： relative growth rate survival rate vegetation restoration

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