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Influence of Accompanying Anions on Potassium Retention and Leaching in Potato Growing Alluvial soils

Pedosphere 2013年第4期23卷 464-471页

作者： V.SHARMA K.N.SHARMA Department of soils Punjab Agricultural University

A column study was carried out to assess the influence of accompanying anions on potassium （K） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg-1 through different sources having different accompanying anions （CI-, SO^-, NO3 and H2PO4-）. Maximum K was retained in the top 0-15 cm layer with a sharp decrease in K content occurring in 15 30 cm layer of the soil column. The trend was similar for both levels of applied K as well as frequency of leaching and soil type. The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg-1, indicating higher potential of clay rich soil to adsorb K. In general, the K leaching in presence of the accompanying anions followed the order of SO4^2-≤ H2PO42- 〈 NO3 = Cl-. Highest 1 mol·L^-1 CH3COONH4-extractable K was retained when K was applied along with SO4^2- and H2PO4 anions, and the least was retained when accompanying anion was Cl-. The influence of anions was more pronounced in the light textured soil and at high amounts of K application. Higher levels of K application resulted in higher losses of K, especially in sandy loam soil as observed from the leachate concentration. Among the different K sources, the maximum amount of K leaching was noticed in the soil column amended with KC1. After four leachings, the maximum amount of K leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in Khanaura sandy loam at 60 mg K kg-1 of soil application through KC1. These concentrations were lower than the recommended guideline of the World Health Organisation （12.00 mg L-1）.

关键词： column study leaching events potassium application potassium sources soil texture

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Effective stress in soils under different saturation conditions

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Journal of Central South University 2011年第6期18卷 2137-2142页

作者：徐浩峰谢康和 Key Laboratory of Soft soils and Geoenvironmental Engineering of Ministry of Education Zhejiang University Ningbo Institute of Technology Zhejiang University

BISHOP’s effective stress or two state stress variables are unsatisfactory for unsaturated soils where one of fluid phases is discontinuous, so new expressions of effective stress should be founded. The approach for derivation was according to the principle of equilibrium of forces (i.e., the stress-sharing principle), and it was firstly validated by demonstrating TERZAGHI’s principle of effective stress. And then, the derivations were subdivided into four parts according to different pore air states: 1) air bubbles were spherical and suspended in pore water; 2) air bubbles were bound on soil skeleton; 3) air bubbles held almost the single section of pore; 4) air phase was continuous. The different formulae of effective stress were presented. Conclusions are drawn as follows: 1) For nearly-saturated soils, the "real" effective stress would be a little smaller than TERZAGHI’s effective stress; 2) For soils in which air phase is discontinuous in the form of bubbles, a new concept of pore air elastic pressure is put forward, and the total stress can be constituted by effective stress, pore water pressure and pore air elastic pressure; 3) For soils in which air phase is continuous, effective stress is equal to the value of the total stress plus suction; 4) Suction can be divided into two parts: one is the effect caused by additional pressure, and the other is the contract action by the "skin".

关键词： unsaturated soils effective stress suction surface tension occluded gas saturation

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Surface-mounted bender elements for measuring horizontal shear wave velocity of soils

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第11期9卷 1490-1496页

作者： Yan-guo ZHOU Yun-min CHEN Yoshiharu ASAKA Tohru ABE MOE Key Laboratory of Soft soils and Geoenvironmental Engineering Zhejiang University Hangzhou 310027 China Institute of Geotechnical Engineering Zhejiang University Hangzhou 310027 China Institute of Technology Shimizu Corporation Tokyo 135-8530 Japan

The bender element testing features its in-plane directivity, which allows using bender elements to measure the shear wave velocities in a wider range of in-plane configurations besides the standard tip-to-tip alignment. This paper proposed a novel bender element testing technique for measuring the horizontal shear wave velocity of soils, where the bender elements are surface- mounted and the axes of the source and receiver elements are parallel to each other. The preliminary tests performed on model ground of silica sand showed that, by properly determining the travel distance and time of the shear waves, the surface-mounted bender elements can perform as accurately as the conventional "tip-to-tip" configuration. Potentially, the present system provides a promising nondestructive tool for characterizing geomaterials and site conditions both in laboratory and in the fields.

关键词： Bender elements Shear wave velocity Model test Nondestructive evaluation Surface-mounted Sand

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Assessment of Heavy Metals Immobilization in Artificially Contaminated soils Using Some Local Amendments

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Open Journal of Metal 2013年第2期3卷 68-76页

作者： Noha H. Abdel-Kader Reda R. Shahin Hasan A. Khater soils Department Faculty of Agriculture Cairo University Giza Egypt

Three alluvial soil samples with different textures were artificially polluted with chloride solutions of Cd, Pb, Co and chromate solution for Cr. The aqua-regia extracted concentration ranges in the artificially polluted soils were 1134 - 1489 mg·kg-1 for Pb, 854 - 938 mg·kg-1 for Cr, 166 - 346 mg·kg-1 for Co and 44 - 54 mg·kg-1 for Cd. The aqua-regia extracted metals were the highest in the spiked clay soil due to its high adsorption capacity. Rock phosphate (PR), lime-stone (LS) and Portland-cement (Cem) were mixed with the spiked soils at 1% and 2% rates (w/w) and incubated at 30 C for 2, 7, 14, 30, 60, 150 and 360 days. The extracted DTPA metals significantly decreased with different magnitudes with increasing the incubation period accompanied by increases in both pH and EC. The data showed that cement (Cem) treatment dropped the DTPA-Pb from @ 1000 to @ 400 mg·kg-1 in all the studied soils (60% decrease) in the first 2 months while it gradually decreased from 400 to 200 mg·kg-1 (20% decrease) in the next 10 months. Limestone (LS) and rock phosphate (PR) materials were relatively less effective in lowering DTPA-Pb after 12 months of incubation. The data showed also that cement (Cem) treatment was the most effective one in lowering DTPA-Cd by @ 60% as compared to the un-amended soils after 12 months of soil incubation. Extractable DTPA-Co and Cr showed consistent decreases with time down to nearly 50% of un-amended soils due to the effect of the added amendments after 12 months of incubation with superior reductions for the cement treatment in all the investigated soils. The statistical analysis confirmed that in all the studied metals and treatment, cement treatment (Cem) was significantly the most effective in lowering the DTPA extracted metals as indicated from LSD test. It was found that up to 73% and 57% of the applied Pb and Cd, respectively, were fixed by only 1% cement. However, the present study showed that from the practical and economic points of view

关键词： Heavy Metals Immobilization Efficiency Rock Phosphate Portland Cement Lime-Stone

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Using pXRF and vis-NIR spectra for predicting properties of soils developed in loess

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Pedosphere 2022年第4期32卷 602-615页

作者： Gafur GOZUKARA Yakun ZHANG Alfred E.HARTEMINK University of Wisconsin-Madison Department of Soil ScienceFD Hole Soils Lab1525 Observatory DriveMadison WI 53706USA Eskisehir Osmangazi University Department of Soil Science and Plant NutritionEskisehir 26160Turkey

Visible near-infrared (vis-NIR) and portable X-ray fluorescence (pXRF) spectrometers have been increasingly utilized for predicting soil properties worldwide. However, only a few studies have focused on splitting the predictive models by horizons to evaluate prediction performance and systematically compare prediction performance for A, B, and combined A+B horizons. Therefore, we investigated the performance of pXRF and vis-NIR spectra, as individual or combined, for predicting the clay, silt, sand, total carbon (TC), and pH of soils developed in loess, and compared their prediction performance for A, B, and A+B horizons. Soil samples (176 in A horizon and 172 in B horizon) were taken from Mollisols and Alfisols in 136 pedons in Wisconsin, USA and analyzed for clay, silt, sand, pH, and TC. The pXRF and vis-NIR spectrometers were used to measure the pXRF and vis-NIR soil spectra. Data were separated into calibration (n = 244, 70%) and validation (n = 104, 30%) datasets. The Savitzky-Golay filter was applied to preprocess the pXRF and vis-NIR spectra, and the first 10 principal components (PCs) were selected through principal component analysis (PCA). Five types of predictor, i.e., PCs from vis-NIR spectra, pXRF of beams at 0–40 and 0–10 keV (XRF40 and XRF10, respectively) spectra, combined XRF40 and XRF10 (XRF40+XRF10) spectra, and combined XRF40, XRF10, and vis-NIR (XRF40+XRF10+vis-NIR) spectra, were compared for predicting soil properties using a machine learning algorithm (Cubist model). A multiple linear regression (MLR) model was applied to predict clay, silt, sand, pH, and TC using pXRF elements. The results suggested that pXRF spectra had better prediction performance for clay, silt, and sand, whereas vis-NIR spectra produced better TC and pH predictions. The best prediction performance for sand (R2= 0.97), silt (R2= 0.95), and clay (R2= 0.84) was achieved using vis-NIR+XRF40+XRF10 spectra in B horizon, whereas the best prediction performance for TC (R2= 0.93)

关键词： Cubist model machine learning algorithm portable X-ray fluorescence spectra soil elements visible near-infrared spectra

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Chromium Adsorption in Different Mineralogical Fractions from Subtropical soils

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Pedosphere 2017年第1期27卷 106-111页

作者： Jovana BAVARESCO Jesse R. FINK Maria Lucia K. RODRIGUES Clesio GIANELLO Vidal BARRON Jose TORRENT Department of soils Federal University of Rio Grande do Sul 91540-000 Porto Alegre Rio Grande do Sul (Brazil) Laboratory of soils Federal Institute of Parand 85555-000 Palmas Parand (Brazil) Department of Research and Laboratory Environmental Protection Foundation of Rio Grande do Sul State 90620-090 Porto AlegreRio Grande do Sul (Brazil) Department of Agronomy University of Cdrdoba C4 Building Campus of Rabanales 14071 C6rdoba (Spain)

Safe application of chromium （Cr）-containing organic industrial wastes to soil requires considering the ability of the soil to adsorb Cr. In this study, the maximum Cr adsorption capacity was assessed for the bulk samples and their clay and iron-free clay fractions of four subtropical soils differing in mineralogy. To this end, the samples were supplied with Cr（Ⅲ） nitrate solutions at pH 4.5 or 5.5. The results of Cr（Ⅲ） adsorption fitted to a Freundlich equation and the adsorption capacity was positively correlated with soil organic matter and iron oxide contents. The clay fractions adsorbed more Cr per unit mass than the bulk soils and the iron-free clay fractions. The Cr（Ⅲ） adsorption capacity increased with increasing soil pH due to more charges on adsorbing surfaces. Our results suggest that the soils rich in organic matter and iron oxides and having a pH above 4.5 are suitable for application of Cr（Ⅲ）-loaded industrial wastes.

关键词： adsorption capacity environmental contamination iron-free clay fractions iron oxides point of zero charge specificsurface area

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Thermal state of soils in the active layer and underlain permafrost at the kilometer post 304 site along the China-Russia Crude Oil Pipeline

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Journal of Mountain Science 2016年第11期13卷 1984-1994页

作者： WANG Yong-ping LI Guo-yu JIN Hui-jun LU Lan-zhi HE Rui-xia ZHANG Peng State Key Laboratory of Frozen soils Engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of SciencesLanzhou 730000China Beifang University of Nationalities Yinchuan 750000China Nanjing Tech University Nanjing 210009China

On-site monitoring is very important for understanding formation mechanisms of frost hazards frequently occurring in pipeline foundation soils and for designing and deploying according mitigative measures in permafrost *** thaw subsidence of ground surfaces along the ChinaRussia Crude Oil Pipeline(CRCOP) from Mo'he to Daqing,Heilongjiang Province,Northeast China have been observed at some segments underlain by ice-rich warm(>1.0°C) permafrost since the official operation in January *** monitoring results of the thermal states of foundation soils at the kilometer post(KP) 304 site along the CRCOP are presented in this *** results indicate that during the period from 2012 to 2014,shallow soils(at the depths from0.8 to 4.0 m from ground surface) has warmed by approximately 1.0°C in the lateral range of 1.2 to 2.1 maway from the pipeline axis,and deeper permafrost(such as at the depth of 15 m,or the depth of zero annual amplitude of ground temperatures) by 0.08°C per year 4 m away from the pipe axis,and 0.07°C per year 5 m away from the pipeline *** results indicate an all-season talik has developed around and along the *** thaw bulb,with a faster lateral expansion(compared with the vertical growth),enlarges in summer and shrinks in *** research will provide important references and bases for evaluating thermal influences of warm pipeline on permafrost and for design,construction,operation and maintenance of pipelines in permafrost regions.

关键词： China-Russia Crude Oil Pipeline Permafrost Thermal regime Talik formation Thaw subsidence

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A new equation for dielectric permittivity of saturated soils based on polarization mechanics

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 293-302页

作者： Ren-peng CHEN Yun-min CHEN Wei XU Zhi-gang LIANG Wei FENG MOE Key Laboratory of Soft soils and Geoenvironmental Engineering Zhejiang University Hangzhou 31002 7 China Institute of Geotechnical Engineering Zhejiang University Hangzhou 310027 China Design Institute of Architecture of Hangzhou Hangzhou 310001 China Lexmark lnternational inc. Lexinton KY 40511 USA

Based on polarization mechanisms, such as electronic, ionic and orientational polarizations, a new equation for dielectric permittivity of soil is proposed to interpret the dielectric behavior of a mixture like soil, in terms of polarization process of its components and the interactions between its components. The dielectric permittivity is expressed in terms of a fre-quency-dependent part and a frequency-independent part. These two parts correspond to polarizations occurred at different fre-quency range. It is a new volumetric mixing model with theoretical background. Based on time domain reflectometry (TDR) measurements of saturated soil samples and test data from literature, comparisons of this model with some well established mixing models show that the curves for saturated sand soils and slurries resulted from the new equation, which agree well with TDR measurements, are close to those calculated from Birchak's model.

关键词： Dielectric permittivity Saturated soils Polarization Time domain reflectometry (TDR)

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Major Elements in soils Along a 2.8-km Altitudinal Gradient on the Tibetan Plateau,China

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Pedosphere 2016年第6期26卷 895-903页

作者： WANG Zhaofeng Alfred E.HARTEMINK ZHANG Yili ZHANG Hua DING Mingjun Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences University of Wisconsin-Madison Department of Soil ScienceFD Hole Soils Lab Key Laboratory of Poyang Lake and Watershed Resarch Ministry of EducationJiangxi Normal University

There are a series of special mountain soils on the Tibetan Plateau of China in an alpine environment for the high altitude. However, very few studies have focused on major soil elements in relation to soil formation in this area. Aluminum （Al）, iron （Fe）, calcium （Ca）, sodium （Na）, potassium （K） and magnesium （Mg） contents of 237 topsoil samples covering a 2.8-km altitudinal gradient in uncultivated areas along the Qinghai-Tibet Railway of China were measured using inductively coupled plasma atomic emission spectroscopy. The spatial distribution of the elements and its relationship to the parent rocks and climatic parameters were analyzed. soils along the gradient are derived from a range of parent materials, but most are less than 30 cm deep with little development （Cambisols）. Soil Al, Fe and Mg contents showed a decreasing trend from the start station （Xining Station） to end station （Lhasa Station） of the Qinghai-Tibet Railway, whereas soil K and Na contents were relative stable from Xining Station to the Kunlun Mountains and then increased gradually. Soil Ca content was lower in the southern part of the Tanggula Mountains. The major soil element contents clearly reflected the parent rock and climatic influences. soils with higher Ca content appeared in areas with Ca-Mg carbonate rocks, soils with higher Al were found in areas with silicate-rich and high-Al silicate clastic rocks and silicate-rich aluminosilicate loose sediments. soils with higher K and Na contents appeared in areas with high-K, high-Na and silicate-rich aluminosilicate rocks. Soil Na and K contents were affected by temperature, whereas the contents of Mg, Fe, Ca and Al were more affected by precipitation. Soil Na and K contents increased with increasing temperatures, whereas the contents of Mg, Fe, Ca and Al decreased with increasing precipitation. This analysis provides a relationship between soil properties and rapidly changing environmental conditions. The data can be used to investigate the

关键词： alpine environment climate mountain soil parent material precipitation temperature pedogenesis soil formation

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Laboratory investigations of the thermal strain of frozen soils,using fiber-optic strain gauges based on Bragg gratings

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Research in Cold and Arid Regions 2017年第3期9卷 192-196页

作者： Aleksey Marchenko Nicolai Vasiliev Artem Nesterov Yuri Kondrashov Nikolay Belyaev Department of Arctic Technology UNIS The Laboratory of Static Research of soils JSC "Vedeneev VNIIG" Peter the Great St. Petersburg Polytechnic University (SPb PU)

Measurements of the thermal deformations of frozen soil samples were performed in the cold laboratory in temperature range from 0°C to-12°*** Bragg Gratings strain and temperature sensors were used to measure the deformation and temperature inside the samples.A number of tests with the samples prepared from Kaolin and Cambrian clay saturated with fresh water,and prepared from fine and silt sand saturated with fresh or saline water,are *** deformations of the samples are analyzed depending on the cyclic changes of their temperature.

关键词： thermal expansion frozen soil sand clay fiber-optic sensors hysteresis

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