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Status of soil Zn in Citrus-Cultivated Area of South China

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Pedosphere 1992年第4期2卷 379-382页

作者： OUYANG TAOInstitute of soil Science, A cademia Sinica. P.O. Box 821, Nanjing 210008 (China)

INTRODUCTION In recent 10 years,citrus production has developed rapidly in *** citrus-cul-tivated area of our country is among the largest and its yield occupies the third place inthe world(Shen,1991).However,in some of our citrus-producing areas the yield is onthe low side and the sugar content of the fruit tends to ***“mosaic”-a physio-

关键词： citrus soil type zinc effect

Isothermal diffusion of water vapor in unsaturated soils based on Fick’s second law

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Journal of Central South University 2020年第7期27卷 2017-2031页

作者： LIU Fei-fei MAO Xue-song ZHANG Jian-xun WU Qian LI Ying-ying XU Cheng School of Highway Chang’an UniversityXi’an 710064China Luoyang Rail Transit Group Co. Ltd.Luoyang 471023China

In arid regions, water vapor diffusion predominates the total water migration in unsaturated soil, which significantly influences agriculture and engineering applications. With the aim of revealing the diffusion mechanism of water vapor in unsaturated soil, a water vapor migration test device was developed to conduct the water vapor migration indoor test. The test results demonstrate that the characteristics of water vapor diffusion in unsaturated soil conformed to Fick’s second law. A mathematical model for water vapor diffusion under isothermal conditions in unsaturated soil was established based on Fick’s law. Factors including the initial moisture content gradient, initial moisture content distribution, soil type and temperature that affect the water vapor diffusion coefficient were analyzed. The results show that there was good agreement between the moisture content calculated by the mathematical model and obtained by the indoor experiment. The vapor diffusion coefficient increased with increasing initial moisture content gradient and temperature. When the initial moisture content gradient is constant, the vapor diffusion coefficient increases with the increase of matrix suction ratio in dry and wet soil section. The effect of soil type on the water vapor diffusion coefficient was complex, as both the moisture content and soil particle sizes affected the water vapor diffusion.

关键词： water vapor diffusion coefficient unsaturated soil mathematical model initial moisture content gradient initial moisture content distribution soil type temperature

Comparison of potential potassium leaching associated with organic and inorganic potassium sources in different arable soils in China

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Pedosphere 2022年第2期32卷 330-338页

作者： Dianjun LU Yanhong DONG Xiaoqin CHEN Huoyan WANG Jianmin ZHOU State Key Laboratory of soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China soil and Fertilizer Station of Shandong Province Jinan 250100China

Potassium (K) leaching is detrimental to the maintenance of sustainable arable soil K fertility,especially in low-K fixation *** is not known whether the application of inorganic fertilizers with lower K mobility or crop straw can reduce potential K leaching in low-K fixation arable *** potential K leaching of 14 representative arable soils with different K fixation capacities in China was evaluated with or without the addition of K under two rainfall intensities (90 and 225 mm),and then potential K leaching was assessed in relation to five K sources (KCl,K_(2)SO_(4),KH_(2)PO_(4),maize (Zea mays L.) straw,and rice (Oryza sativa L.) straw).Without K addition,K leaching mainly occurred in sandy soils at 90 mm of rainfall and in soils with greater organic matter at225 mm of *** K addition,the leaching percentage of exogenous K ranged from 0.6%to 11.6%at 90 mm of rainfall and 1.2%to 21.2%at 225 mm of *** greatest K leaching occurred in soils with fewer K-bearing minerals and lower pH at both rainfall *** most cases,KH_(2)PO_(4),which has lower K mobility,markedly reduced K leaching in both high-and low-K leaching soils at the two rainfall *** and rice straw reduced K leaching only in soils with high K leaching,regardless of rainfall amount,whereas more K was leached in soils with lower K leaching at high rainfall *** conclusion,KH_(2)PO_(4) and straw should be preferred for reducing K leaching in low-K fixation arable soils.

关键词： crop straw K-bearing mineral K fixation K source soil type

Compost Effect on Diuron Retention and Transport in Structured Vineyard soils

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Pedosphere 2015年第1期25卷 25-36页

作者： Mathieu THEVENOT Sylvie DOUSSET UMR 6282 Biogosciences Universit de Bourgogne-CNRS6 Bd Gabriel Dijon 21000 (France) UMR 7360 LIEC Universit de Lorraine-CNRSBP 70239 Vand?uvre-lès-Nancy 54506 (France)

Diuron is frequently detected in surface- and groundwater under the vineyards, where organic amendments are often used, in Burgundy of France. Undisturbed column experiments were conducted to study the influence of three composted organic amendments on diuron leaching through columns of two vineyard soils from Vosne-Roman′ee(VR, calcareous Cambisol) and Beaujolais(Bj, sandy Leptosol), France. Bromide(used as non-reactive tracer) and diuron breakthrough curves(BTCs) were analyzed using convectivedispersive equation(CDE), two-region(mobile-immobile, MIM) and two-site models. No influence of the composts was observed on the bromide recovery rates. The CDE model described well the bromide BTCs for all columns of the Bj soil and seven of the VR soil, suggesting a homogeneous water flow. However, for five VR soil columns, the MIM model fitted better, suggesting a partition of the water flow(15%–50% of matrix flow). The texture, the coarse material content and the tillage of the VR soil could explain this heterogeneity. However, for all columns, diuron leaching was greater through the Bj soil(46%–68%) than the VR soil(28%–39%). The compost addition resulted in a contrasting effect on diuron leaching: no difference or a decrease was observed for the VR soil, probably due to an increase of adsorption sites, whereas no difference or an increase was observed for the Bj soil possibly because of interactions and/or competition of diuron with the compost water-extractable organic matter which could facilitate its transport. All the diuron BTCs were best described using the two-site model, suggesting a large proportion of time-dependent sorption sites(30%–50%). The soil type and the nature of the amendments had contrasting influences on diuron transport. Composts with a high water-soluble fraction must be avoided in sandy soils to reduce the risk of groundwater contamination.

关键词： groundwater contamination leaching organic amendment soil type sorption water-extractable organic matter

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 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

Rangeland Grasshoppers in Relation to soils in the Qinghai Lake Region, China

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Pedosphere 2007年第1期17卷 84-89页

作者： NI Shao-Xiang WANG Jie-Chen JIANG Jian-Jun ZHA Yong College of Geographical Science Nanjing Normal University Nanjing 210097 （China） Department of Urban and Resources Science Nanjing UniversityNanjing 910093 （China）

The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10 g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.

关键词： Qinghai Lake rangeland grasshopper soil type soil moisture

Ultimate fate of halosulfuron methyl and its effects on enzymatic and microbial activities in three differently textured soils

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Pedosphere 2023年第6期33卷 880-892页

作者： Pervinder KAUR Jasleen KAUR Harshdeep KAUR Department of Agronomy Punjab Agricultural UniversityPunjab 141001India Department of Chemistry Punjab Agricultural UniversityPunjab 141001India

Halosulfuron methyl is a sulfonylurea herbicide used worldwide for weed control in sugarcane, maize, wheat, and rice production. Considering its environmental impact, this study evaluated the effects of soil type, application rate, and temperature on the dynamics of halosulfuron methyl ***, as soil microbes and enzymes are reliable indicators of the impacts of anthropogenic activities on soil health, the effects of halosulfuron methyl on soil enzymatic and microbial activities were also assessed. The half-life(DT50) of halosulfuron methyl varied from 9.38 to 33.77 d. Increase in temperature accelerated the degradation and DT50 varied from 14.39 to 33.77, 11.05 to 28.94, and 9.38 to 25.41 d at 5, 15, and 25?C, respectively. The metabolites of halosulfuron methyl, including halosulfuron, methyl 3-chloro-5-((4,6-dimethoxy-2-pyrimidinyl) amino)-1-methyl-1H-pyrazole-4-carboxylate,4,6-dimethoxy-2-pyrimidinamine, and methyl 3-chloro-1-methyl-5-sulfamoyl-1H-pyrazole-4-carboxylate, were detected in the studied soils, and their appearance and disappearance varied with application rate, soil type, and incubation temperature. Halosulfuron methyl had transitory harmful effects on soil enzymatic and microbial activities depending on its application rate. The results suggest that the application rate of halosulfuron methyl, soil physicochemical parameters, and temperature should be considered together to ensure satisfactory weed control with reduced environmental risk.

关键词： degradation environmental risks metabolites principal component analysis soil type sulfonylurea herbicides weed control

A new procedure combining GC-MS with accelerated solvent extraction for the analysis of phthalic acid esters in contaminated soils

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Frontiers of Environmental Science & Engineering 2013年第1期7卷 31-42页

作者： Tingting MA Ying TENG Peter CHRISTIE Yongming LUO Yongshan CHEN Mao YE Key Laboratory of soil Environment and Pollution Remediation Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China Graduate University of the Chinese Academy of Sciences Beijing 100049China Agri-Environment Branch Agri-Food and Biosciences Institute Newforge Lane Belfast BT9 5PX United Kingdom State key Laboratory of Environment Simulation and Pollution control (Jomt) Tsinghua University Beijing 100084 China State Key Laboratory of soil and Sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Nanjing 210008 China

An optimized procedure based on gas chromatography-mass spectrometry (GC-MS) combined with accelerated solvent extraction (ASE) is developed for the analysis of six phthalic acid esters (PAEs), which are priority soil pollutants nominated by United States Environmental Protection Agency (USEPA). Quantification of PAEs in soil employs ultrasonic extraction (UE) (USEPA 3550) and ASE (USEPA 3545), followed by clean up procedures involving three different chromatography columns and two combined elution methods. GC-MS conditions under selected ion monitoring (SIM) mode are described and quality assurance and quality control (QA/QC) criteria with high accuracy and sensitivity for target analytes were achieved. Method reliability is assured with the use of an isotopically labeled PAE, di- -butyl phthalate-d4 (DnBP-D4), as a surrogate, and benzyl benzoate (BB) as an internal standard, and with the analysis of certified reference materials (CRM). QA/QC for the developed procedure was tested in four PAE-spiked soils and one PAE-contaminated soil. The four spiked soils were originated from typical Chinese agricultural fields and the contaminated soil was obtained from an electronic waste dismantling area. Instrument detection limits (IDLs) for the six PAEs ranged 0.10–0.31 μg·L and method detection limits (MDLs) of the four spiked soils varied from a range of 20–70 μg·kg to a range of 90– 290 μg·kg . Linearity of response between 20 μg·L and 2 mg·L was also established and the correlation coefficients ( ) were all>0.998. Spiked soil matrix showed relative recovery rates between 75 and 120% for the six target compounds and about 93% for the surrogate substance. The developed procedure is anticipated to be highly applicable for field surveys of soil PAE pollution in China.

关键词： phthalic acid esters quality assurance and quality control soil type accelerated solvent extraction certified reference materials

A site dependent top height growth model for hybrid aspen

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Journal of Forestry Research 2013年第4期24卷 691-698页

作者： Tord Johansson Department of Energy and Technology Swedish University of Agricul- tural Sciences

In this study height growth models for hybrid aspen were developed using three growth equations. The mean age of the hybrid aspen was 21 years （range 15-51 years） with a mean stand density of 946 stems ha-~ （87-2374） and a mean diameter at breast height （over bark） of 19.6 cm （8.5-40.8 cm）. Site index was also examined in relation to soil type. Multiple samples were collected for three types of soil： light clay, medium clay and till. Site index curves were constructed using the col- lected data and compared with published reports. A number of dynamic equations were assessed for modeling top-height growth from total age.

关键词： top height farmland hybrid aspen site index soil types stands total age soil type