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Effects of Corn Stalk-composted Organic Fertilizer on Physiochemical Properties of Tobacco-growing Soil
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作者 刘洋 李爱华 《Agricultural Science & Technology》 CAS 2016年第11期2551-2554,共4页
In order to explore the method of returning corn stalk into field, the effects of returning corn stalk direcfly into soil and applying corn stalk-composted orgar^c fertilizer into soil on the physiochemical properties... In order to explore the method of returning corn stalk into field, the effects of returning corn stalk direcfly into soil and applying corn stalk-composted orgar^c fertilizer into soil on the physiochemical properties of tobacco-growing soil were studied. The results showed that returning corn stalk into soil could reduce soil bulk density and increase soil porosity, so as to improve the water and fertilizer retention capacity of tobacco-growing soil. At the same time, returning corn stalk into soil could also increase the organic matter, available phosphorus and available potassi- um contents in tobacco-growing soil. In the early field growth stage of tobacco, soil alkali-hydrolyzable nitrogen content decreased slightly; but in the middle and later field growth stage, the alkali-hydrolyzable nitrogen content in tobacco-growing soil increased. The treatment effect of corn stalk+urea+fermentation bacteria and corn stalk+urea+BM was better than that of the control (returning corn stalk directly into soil), indicating that the corn stalk-composted organic fertilizer had certain popular- ization value. 展开更多
关键词 tobacco-growing soil Corn stalk Organic fertilizer Physiochemical properties NUTRIENT
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Variation of Enzyme Activity in Flue-cured Tobacco-growing Soil Planted with Different Lastseason Crops
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作者 毛振萍 冯成恩 +5 位作者 周冀衡 向炳清 吴春发 邓蓓蕾 刘红 王婧 《Agricultural Science & Technology》 CAS 2014年第10期1719-1722,1769,共5页
The rice soil (last crop was rice) and arid red soil (last crop was corn) were used as a test material for the pot experiment. The variation of enzyme activi-ty in flue-cured tobacco-growing soil planted with diff... The rice soil (last crop was rice) and arid red soil (last crop was corn) were used as a test material for the pot experiment. The variation of enzyme activi-ty in flue-cured tobacco-growing soil planted with different last-season crops was in-vestigated at different growth stages in this study. The results showed the activity variation of the 3 enzymes differed in the 2 soils at different growth stages. The catalase activity in the arid red soil trended to decrease overal from the vigorous growing stage to harvesting stage; while it decreased gradual y in the rice soil until the harvesting stage. The phosphatase activity in the 2 soils al increased with the proceeding of growth period. The urease activity in the arid red soil decreased gradual y at different growth stages, but the variation of urease activity in rice soil was irregular. During the growth of flue-cured tobacco, the catalase and urease ac-tivity in the arid red soil increased first and then decreased, and the phosphatase activity increased gradual y. ln rice soil, the catalase activity increased first and then decreased; the phosphatase activity decreased first and then increased; the urease activity increased first, then decreased and increased last. The activity of al the en-zymes in the 2 soils showed significant differences compared to the control except some enzymes at the vigorous growing stage. lt was suggested the planting of flue-cured tobacco would affect greatly the soil enzyme activities. 展开更多
关键词 Flue-cured tobacco soil type soil enzyme activity Growth of flue-cured tobacco
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The Distribution Characteristics of Soil pH Values of Tobacco-growing Areas in Dali City and Its Correlation with Soil Nutrients 被引量:1
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作者 杨春文 赵宇 +5 位作者 王新中 杨成伟 杨志娟 户艳霞 孙军伟 王德勋 《Agricultural Science & Technology》 CAS 2015年第5期951-953,972,共4页
[Objective] The aim was to study the distribution characteristics of soil pH values and its correlation with soil nutrients in tobacco-growing areas. [Method] Soil nutrients of 43 samples from tobacco-growing areas in... [Objective] The aim was to study the distribution characteristics of soil pH values and its correlation with soil nutrients in tobacco-growing areas. [Method] Soil nutrients of 43 samples from tobacco-growing areas in Dali City were analyzed.[Results] The results showed that average pH value of tobacco-planting soil in Dali City was 6.52, soil samples which suited for flue-cured tobacco cultivation accounted for 72.09% of total soil samples. In four soil types of tobacco-growing areas, the pH values in a descending order were as follows: alluvial soil〉 paddy soil 〉purple soil〉 red soil. At the altitude range of 1 780-2 200 m, soil pH values showed a gradual decreasing trend. The average contents of soil organic matters were relatively abundant and generally suited for high-quality tobacco cultivation; the average contents of soil alkali-hydrolyzable nitrogen, available phosphorus, exchangeable calcium and exchangeable magnesium were generally at medium and abundant level, however,their rations under the medium level in some tobacco-growing areas were 6.98%,11.63%, 2.33% and 4.65%, respectively; moreover, soil with lower available potassium contents occupied a large proportion, namely 58.14%. [Conclusion] Soil pH values had significant correlation with exchangeable magnesium and exchangeable magnesium, however, they had no significant correlation with other soil nutrients. 展开更多
关键词 tobacco-growing areas soil pH values soil nutrients Correlation analysis
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Evaluation of Soil Fertility Suitability of Yiliang Tobacco-growing Areas in Yunnan Province 被引量:4
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作者 Yujun WANG Jiheng ZHOU +3 位作者 Xinlang LU Lijuan CHEN Chao WANG Jiaming YANG 《Agricultural Science & Technology》 CAS 2014年第12期2150-2155,共6页
[Objective]This study was conducted to evaluate the soil fertility in Yiliantobacco-growing areas of Hunan Province.[Method]The soil nutrient contents iseven tobacco-growing towns of Yiliang County,Yunnan Province wer... [Objective]This study was conducted to evaluate the soil fertility in Yiliantobacco-growing areas of Hunan Province.[Method]The soil nutrient contents iseven tobacco-growing towns of Yiliang County,Yunnan Province were surveyefrom 2010 to 2013 and integrated soil fertility index(SFI value)was calculated tanalyze the soil fertility suitability in theses areas.[Result]The soil p H,contents oorganic matter,hydrolytic N,rapidly available K and available B were all at an appropriate level,while the contents of rapidly available P,available Mg,available Zand water-soluble Cl-were high.Among them,the contents of available P and water-soluble Cl-had great variation.Finally,the soil fertility suitability of Yiliang tobacco-growing areas was graded based on their SFI values.As a result,20%of thestobacco-growing areas were in Grade I,47.7%in Grade II,29.3%in Grade III1.5%in Grade IV and 1.5%in Grade V.The average SFI was 0.61.From 2010 t2013,the p H value and available Mg content reduced year by year,while the contents of organic matter,hydrolytic N,rapidly available P,rapidly available K,available Zn,available B and water-soluble Cl-were increased. 展开更多
关键词 tobacco-growing soil FERTILITY Comprehensive evaluation Yiliang ofYunnan Province
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Semi-analytical solution for drained expansion analysis of a hollow cylinder of critical state soils 被引量:1
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作者 He Yang Jialiang Zhang +1 位作者 Haisui Yu Peizhi Zhuang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第6期2326-2340,共15页
The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by ... The expansion of a thick-walled hollow cylinder in soil is of non-self-similar nature that the stress/deformation paths are not the same for different soil material points.As a result,this problem cannot be solved by the common self-similar-based similarity techniques.This paper proposes a novel,exact solution for rigorous drained expansion analysis of a hollow cylinder of critical state soils.Considering stress-dependent elastic moduli of soils,new analytical stress and displacement solutions for the nonself-similar problem are developed taking the small strain assumption in the elastic zone.In the plastic zone,the cavity expansion response is formulated into a set of first-order partial differential equations(PDEs)with the combination use of Eulerian and Lagrangian descriptions,and a novel solution algorithm is developed to efficiently solve this complex boundary value problem.The solution is presented in a general form and thus can be useful for a wide range of soils.With the new solution,the non-self-similar nature induced by the finite outer boundary is clearly demonstrated and highlighted,which is found to be greatly different to the behaviour of cavity expansion in infinite soil mass.The present solution may serve as a benchmark for verifying the performance of advanced numerical techniques with critical state soil models and be used to capture the finite boundary effect for pressuremeter tests in small-sized calibration chambers. 展开更多
关键词 Cavity expansion Drained analysis Boundary effect Critical state soil Non-self-similar Eulerian-Lagrangian approach
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Physical and mechanical properties and microstructures of submarine soils in the Yellow Sea 被引量:1
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作者 Zhuangcai Tian Yihua Chang +6 位作者 Sichao Chen Gengchen Wang Yanhong Hu Chuan Guo Lei Jia Lei Song Jianhua Yue 《Deep Underground Science and Engineering》 2024年第2期197-206,共10页
In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical propertie... In recent years,the exploration of seabed has been intensified,but the submarine soils of silt and sand in the Yellow Sea area have not been well investigated so far.In this study,the physical and mechanical properties of silt and sand from the Yellow Sea were measured using a direct shear apparatus and their microstructures were observed using a scanning electron microscope.The test results suggest that the shear strength of silt and sand increases linearly with the increase of normal stress.Based on the direct shear test,the scanning electron microscope was used to observe the section surface of sand.It is observed that the section surface becomes rough,with many“V”‐shaped cracks.Many particles appear on the surface of the silt structure and tend to be disintegrated.The X‐ray diffraction experiment reveals that the sand and silt have different compositions.The shear strength of sand is slightly greater than that of silt under high stress,which is related to the shape of soil particles and the mineral composition.These results can be a reference for further study of other soils in the Yellow Sea;meanwhile,they can serve as soil parameters for the stability and durability analyses of offshore infrastructure construction. 展开更多
关键词 direct shear test MICROSCOPE physical properties submarine soil Yellow Sea
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Liquefaction susceptibility and deformation characteristics of saturated coral sandy soils subjected to cyclic loadings-a critical review 被引量:1
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作者 Chen Guoxing Qin You +3 位作者 Ma Weijia Liang Ke Wu Qi C.Hsein Juang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期261-296,共36页
Coral sandy soils widely exist in coral island reefs and seashores in tropical and subtropical regions.Due to the unique marine depositional environment of coral sandy soils,the engineering characteristics and respons... Coral sandy soils widely exist in coral island reefs and seashores in tropical and subtropical regions.Due to the unique marine depositional environment of coral sandy soils,the engineering characteristics and responses of these soils subjected to monotonic and cyclic loadings have been a subject of intense interest among the geotechnical and earthquake engineering communities.This paper critically reviews the progress of experimental investigations on the undrained behavior of coral sandy soils under monotonic and cyclic loadings over the last three decades.The focus of coverage includes the contractive-dilative behavior,the pattern of excess pore-water pressure(EPWP)generation and the liquefaction mechanism and liquefaction resistance,the small-strain shear modulus and strain-dependent shear modulus and damping,the cyclic softening feature,and the anisotropic characteristics of undrained responses of saturated coral sandy soils.In particular,the advances made in the past decades are reviewed from the following aspects:(1)the characterization of factors that impact the mechanism and patterns of EPWP build-up;(2)the identification of liquefaction triggering in terms of the apparent viscosity and the average flow coefficient;(3)the establishment of the invariable form of strain-based,stress-based,or energy-based EPWP ratio formulas and the unique relationship between the new proxy of liquefaction resistance and the number of cycles required to reach liquefaction;(4)the establishment of the invariable form of the predictive formulas of small strain modulus and strain-dependent shear modulus;and(5)the investigation on the effects of stress-induced anisotropy on liquefaction susceptibility and dynamic deformation characteristics.Insights gained through the critical review of these advances in the past decades offer a perspective for future research to further resolve the fundamental issues concerning the liquefaction mechanism and responses of coral sandy sites subjected to cyclic loadings associated with seismic events in marine environments. 展开更多
关键词 liquefaction susceptibility dynamic deformation characteristics coral sandy soil cyclic loading review and prospect
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Dynamic Changes of Tobacco-growing Soil Nutrients and Enzymes After Application of Amelioration Materials 被引量:1
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作者 Zhanghong CAO Gexuan SU +8 位作者 Yongjun LIU Shuguang PENG Yongsheng DENG Jin CHEN Deyuan PENG Zhenghua WANG Jingjing WU Qianping YAN Xiaohua DENG 《Agricultural Biotechnology》 CAS 2020年第4期87-91,共5页
[Objectives]This study was conducted to clarify the improvement effects of different soil amelioration materials such as lime,green manure and bio-organic fertilizer on acidic tobacco-planting soil.[Methods]The dynami... [Objectives]This study was conducted to clarify the improvement effects of different soil amelioration materials such as lime,green manure and bio-organic fertilizer on acidic tobacco-planting soil.[Methods]The dynamic changes of soil pH,soil nutrients and enzyme activity were studied by applying lime,lime+green fertilizer,and lime+green fertilizer+biological organic fertilizer.[Results]①After the application of amelioration materials,the soil pH and available phosphorus content of tobacco-growing soil showed a stepwise change of first increasing and then decreasing,and became stable at 60 d after tobacco transplanting;the soil organic matter,alkali-hydrolyzable nitrogen and available potassium content showed a gradual change trend of"high-low-high";and the soil invertase and urease activity showed a gradual change trend of"low-high-low".②To 90 d after tobacco transplanting,the application of amelioration materials increased soil pH by 1.29-1.62 units,and increased organic matter content by 15.21%-20.86%,alkali-hydrolyzable nitrogen content by 6.83%-18.17%,available phosphorus content by 54.15%-217.85%,rapidly available potassium content by 11.42%-30.86%,soil invertase activity by 70.09%-18.93%,and soil urease activity by 64.07%-130.47%.③The combination of lime+green manure+alkaline microbial organic fertilizer had the best effect on the improvement of acidic tobacco-growing soil,and the effect of lime+green manure+acid microbial organic fertilizer on acidic soil was the second.[Conclusions]When applying lime,green fertilizer and alkaline bio-organic fertilizer should be applied to achieve sustainable improvement of strongly acidic soil. 展开更多
关键词 Amelioration materials soil pH Main nutrients of tobacco-growing soil soil enzymes
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Extended wet sieving method for determination of complete particle size distribution of general soils 被引量:1
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作者 Shengnan Ma Yi Song +2 位作者 Jiawei Liu Xingyu Kang Zhongqi Quentin Yue 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第1期242-257,共16页
The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional meth... The traditional standard wet sieving method uses steel sieves with aperture?0.063 mm and can only determine the particle size distribution(PSD)of gravel and sand in general soil.This paper extends the traditional method and presents an extended wet sieving method.The extended method uses both the steel sieves and the nylon filter cloth sieves.The apertures of the cloth sieves are smaller than 0.063 mm and equal 0.048 mm,0.038 mm,0.014 mm,0.012 mm,0.0063 mm,0.004 mm,0.003 mm,0.002 mm,and 0.001 mm,respectively.The extended method uses five steps to separate the general soil into many material sub-groups of gravel,sand,silt and clay with known particle size ranges.The complete PSD of the general soil is then calculated from the dry masses of the individual material sub-groups.The extended method is demonstrated with a general soil of completely decomposed granite(CDG)in Hong Kong,China.The silt and clay materials with different particle size ranges are further examined,checked and verified using stereomicroscopic observation,physical and chemical property tests.The results further confirm the correctness of the extended wet sieving method. 展开更多
关键词 Particle size distribution(PSD) General soil SILT CLAY Wet sieving Physical and chemical properties
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Physico-Chemical Analysis of Soils Used for Pineapple Cultivation in the Sub-Prefectures of Maferinyah and Friguiagbé (Prefectures of Forécariah and Kindia) Republic of Guinea 被引量:1
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作者 Sâa Gerard Tolno Saran Camara +2 位作者 Amadou Sylla Adama Moussa Sakho Lounceny Traore 《Journal of Agricultural Chemistry and Environment》 2024年第3期251-262,共12页
Over the years, pineapple production in the Republic of Guinea has become less competitive in the West African sub-region, with a world ranking of 144th. It is therefore only natural to review certain parameters in or... Over the years, pineapple production in the Republic of Guinea has become less competitive in the West African sub-region, with a world ranking of 144th. It is therefore only natural to review certain parameters in order to improve this ranking. To do this, certain physico-chemical parameters of soil samples from Friguiagbé and Maferinyah (in the Kindia and Forécariah prefectures) were taken and analysed using the following techniques: Pipette de Robinson, Anne, Bray II, Kapen HICDVITZ, Mc. Lead (1982). The analytical results show that the soils at Friguiagbé in Kindia and Maferinyah in Forécariah are acidic, with pH values of 4.4 and 4.7 (fields I and II) and 4.8 and 4.7 (fields I and II) respectively. The soils have a silty-sandy texture. This study could therefore serve as a guide for the Ministry of Agriculture of the Republic of Guinea. 展开更多
关键词 soil Pineapple Crop Physico-Chemical Analysis
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Temporal and environmental factors drive community structure and function of methanotrophs in volcanic forest soils
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作者 Rusong Chai Hongjie Cao +3 位作者 Qingyang Huang Lihong Xie Fan Yang Hongbin Yin 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期1-13,共13页
Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The s... Methanotrophs,organisms that obtain oxygen by oxidizing methane,are recognized as the only known biological sink for atmospheric CH_4,and forest soil methanotrophs play crucial roles in mitigating global warming.The succession patterns of methanotrophic communities and functions in Wudalianchi volcano forest soils could provide a basis for the study of evolutionary mechanisms between soil microorganisms,the environment,and carbon cycling of temperate forest ecosystems under climate change.In this study,the characteristics and drivers of methanotrophic community structure and function of two volcanic soils at different stages of development are analyzed,including an old volcano and a new volcano,which most recently erupted 300 years and 17-19×10^(5)years ago,respectively,and a non-volcano hills as control,based on space for time substitution and Miseq sequencing and bioinformation technology.The results showed that CH_(4) fluxes were significantly higher in old-stage volcano forest soils than new-stage forest soils and non-volcano forest soils.There were significant differences in the community composition and diversity of soil methanotrophs from different volcano forest soils.Methylococcus was the dominant genus in all soil samples.Additionally,the relative abundance of Methylococcus,along with Clonothrix,Methyloglobulus,Methylomagum,Methylomonas and Methylosarcina,were the important genera responsible for the differences in methanotrophic community structure in different volcano forest soils.The relative abundance of methanotroph belonging toγ-proteobacteria was significantly higher than that belonging toα-proteobacteria(P<0.05).Chao1,Shannon and Simpson indices of soil methanotrophic community were significantly lower in new-stage volcanos and were significantly affected by bulk density,total porosity,p H,nitrate,dissolved organic carbon and dissolved organic nitrogen.There were significant differences in community structure between new-stage and old-stage volcanoes.Bulk density and p H are important soil properties contributing to the divergence of methanotrophs community structure,and changes in soil properties due to soil development time are important factors driving differences in methanotrophs communities in Wudalianchi volcanic soils. 展开更多
关键词 METHANOTROPHS pmo A soil development stage Volcanoes Forest soils
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Diatom-induced impact on shear strength characteristics of finegrained soils
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作者 Gang Wang Xianwei Zhang +2 位作者 Xinyu Liu Yiqing Xu Ran An 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第11期4711-4726,共16页
Diatomaceous soils,composed of diatom microfossils with biological origins,have geotechnical properties that are fundamentally different from those of conventional non-diatomaceous fine-grained soils.Despite their hig... Diatomaceous soils,composed of diatom microfossils with biological origins,have geotechnical properties that are fundamentally different from those of conventional non-diatomaceous fine-grained soils.Despite their high fines content,diatomaceous soils typically exhibit remarkably high shear resistance,approaching that of sandy soils.However,the exact role that diatoms play in controlling the mechanical properties of fine-grained soils and the underlying mechanisms remain unclear.In light of this,the shear strength response of diatomaceous soils was systematically investigated using consolidated undrained triaxial compression tests on diatomekaolin mixtures(DKMs)with various diatom contents and overconsolidation ratios.The micro-and nano-scale structures of the soil samples were characterized in detail using scanning electron microscope(SEM)and atomic force microscope(AFM)to interpret the abnormal shear strength parameters of diatomaceous soils.The results indicated that the presence of diatoms could contribute to significantly higher strength,e.g.the friction angle of DKMs was improved by 72.7%to 37and the value of undrained shear strength tripled with diatom content increasing from 20%to 100%.Such significant improvement in soil strength with diatom inclusion could be attribute to the hard siliceous skeleton of diatoms and the interlocking between particles with rough surfaces,which were quantitatively analyzed by the surface roughness parameters with AFM.Furthermore,a conceptual model established based on the macro-mechanical tests and microscopic observations portrays a microstructural evolution of soils with increasing diatoms.The microstructure of soils was gradually transformed from the matrix-type to the skeletal one,resulting in a continual augmentation in shear strength through mutual interactions between diatom microfossils.This paper provides new insights into the multi-scale structural properties of diatoms and significantly advances our understanding of the mechanical behavior of diatomaceous soils. 展开更多
关键词 DIATOM Diatomaceous soil Fine-grained soil Shear strength Microstructure Atomic force microscope(AFM)
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Geochemical Characterization of Soils in the Playa Lake Environment of Laguna de Encinillas, Chihuahua, Mexico
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作者 María Fernanda Ponce-González Alejandro Villalobos-Aragón +1 位作者 Vanessa Verónica Espejel-García Daphne Espejel-García 《Open Journal of Geology》 CAS 2024年第9期900-918,共19页
Laguna de Encinillas, located in Chihuahua, Mexico, is an ephemeral lake situated within a playa lake sedimentary depositional environment. This region plays a significant role in the aquifer supplying water to Chihua... Laguna de Encinillas, located in Chihuahua, Mexico, is an ephemeral lake situated within a playa lake sedimentary depositional environment. This region plays a significant role in the aquifer supplying water to Chihuahua City. A surficial soil sampling campaign was conducted in 2017, 2018, and 2021 to assess the potential impact of surface soil composition on groundwater quality. The collected soil samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) following microwave-assisted digestion. The analytical results were employed to generate spatial distribution maps of elemental concentrations using QGIS, applying interpolation methods such as inverse distance weighting (IDW) and Kriging. The analysis revealed elevated concentrations of beryllium (Be), calcium (Ca), cadmium (Cd), chromium (Cr), magnesium (Mg), and strontium (Sr) in the eastern part of the study area. In contrast, arsenic (As) and iron (Fe) were more prevalent in the western sector. Notably, high levels of barium (Ba), silver (Ag), cobalt (Co), potassium (K), and scandium (Sc) were identified in the northeastern region. At the same time, nickel (Ni), titanium (Ti), and vanadium (V) were concentrated in the northern portion. Manganese (Mn) was particularly prominent in the southern area. The geogenic source of these elements is likely linked to the volcanic rocks from the surrounding mountain ranges. 展开更多
关键词 Groundwater Quality soils El Sauz-Encinillas Aquifer CHIHUAHUA GIS
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Effect of Some Physical Factors on Interrill Erosion of Soils in Gidan-Kwanu Area, Nigeria
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作者 Ebierin Akpoebidimiyen Otuaro John Jiya Musa Micheal Abolarin 《Journal of Environmental Protection》 2024年第4期475-484,共10页
Savanna regions in Nigeria face environmental degradation and barren land, negatively impacting food and agricultural productivity. Inter-rill erosion occurs due to raindrop impact and transport, particularly on hill ... Savanna regions in Nigeria face environmental degradation and barren land, negatively impacting food and agricultural productivity. Inter-rill erosion occurs due to raindrop impact and transport, particularly on hill slopes. A study was conducted using a sprinkler rainfall simulator and plot experiment to study soil erosion processes. Soil samples were collected from four farms in Gidan Kwanu, with varying moisture content. Sand content ranged from 46.0% to 76.20%, silt from 11.30% to 23.50%, and clay from 11.0% to 30.0%. Uncultivated and bare land had a higher average porosity (15.47% and 14.99%), while cultivated land had lower porosity (14.4%). The study found that most people in Gidan-Kwanu primarily practice farming, which is season-dependent and rain-fed. Soil type and texture significantly contribute to inter-rill erosion, with cultivated and uncultivated soil being more resistant to erosion than bare land soil. The study concluded that farming practices in Gidan-Kwanu are primarily season-dependent and rain-fed. Soil type and texture significantly contribute to inter-rill erosion, with cultivated and uncultivated soil being more resistant to erosion than bare land soil. 展开更多
关键词 AGRICULTURE EROSION FARMING POROSITY soil
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Afforestation increases microbial diversity in low-carbon soils
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作者 Xuesen Pang Chuankuan Wang +1 位作者 Chengjie Ren Zhenghu Zhou 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期14-22,共9页
Afforestation has an important role in biodiversity conservation and ecosystem function improvement.A meta-analysis was carried out in China,which has the largest plantation area globally,to quantify the effects of pl... Afforestation has an important role in biodiversity conservation and ecosystem function improvement.A meta-analysis was carried out in China,which has the largest plantation area globally,to quantify the effects of plantings on soil microbial diversity.The results showed that the overall effect of afforestation on soil microbial diversity was positive across the country.Random forest algorithm suggested that soil carbon was the most important factor regulating microbial diversity and the positive response was only found with new plantings on low-carbon bare lands but not on high-carbon farmlands and grasslands.In addition,afforestation with broadleaved species increased microbial diversity,whereas planting with conifers had no effect on microbial diversity.This study clarified the effects of plantings on soil microbial diversity,which has an important implication for establishing appropriate policies and practices to improve the multiple functionalities(e.g.,biodiversity conservation and climate change mitigation)during plantation establishment. 展开更多
关键词 AFFORESTATION Microbial diversity soil microbial communities Species-energy theory Plantations
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A bounding surface visco-plasticity model considering generalized spacing ratio of soils
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作者 Xiaosen Kang Hongjian Liao +1 位作者 Qiangbing Huang Jianbing Peng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第5期1832-1846,共15页
The non-unique critical state of soils with time-dependent behaviors is a significant issue in geotechnical engineering problems.However,previous bounding surface plasticity models cannot predict accurately the non-un... The non-unique critical state of soils with time-dependent behaviors is a significant issue in geotechnical engineering problems.However,previous bounding surface plasticity models cannot predict accurately the non-unique critical state of soils,because the distance between the compression line and critical state line charged by strain-rate effect is basically neglected.To fill this gap,a generalized spacing ratio of soils is defined in the elasto-viscoplastic framework,and a bounding surface visco-plasticity model is formulated and verified,which can consider the generalized spacing ratio.Specifically,the generalized spacing ratio of soils reflects the distance between the compression line and the critical state line of soils with time-dependent behaviors.Then,the generalized spacing ratio is introduced into an improved anisotropic bounding surface.A new expression of the visco-plastic multiplier is derived by solving the consistency equation of an anisotropic bounding surface.In the expression,a strain rate index is proposed to account for the strain-rate effect on visco-plastic strain increment,and a visco-plastic hardening modulus is derived to predict the visco-plastic response of soils in overconsolidation conditions.The model is then verified through constant strain rate tests and creep tests.Notably,it can capture the non-unique critical states of soils with time-dependent behaviors due to the generalized spacing ratio and the creep rupture of soils due to the visco-plastic multiplier that considers the stress ratio and visco-plastic strain rate. 展开更多
关键词 soil Constitutive model Visco-plastic behavior Strain rate CREEP ANISOTROPIC
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Accurate method based on data filtering for quantitative multi-element analysis of soils using CF-LIBS
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作者 韩伟伟 孙对兄 +7 位作者 张国鼎 董光辉 崔小娜 申金成 王浩亮 张登红 董晨钟 苏茂根 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第6期149-158,共10页
To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis o... To obtain more stable spectral data for accurate quantitative analysis of multi-element,especially for the large-area in-situ elements detection of soils, we propose a method for a multielement quantitative analysis of soils using calibration-free laser-induced breakdown spectroscopy(CF-LIBS) based on data filtering. In this study, we analyze a standard soil sample doped with two heavy metal elements, Cu and Cd, with a specific focus on the line of Cu I324.75 nm for filtering the experimental data of multiple sample sets. Pre-and post-data filtering,the relative standard deviation for Cu decreased from 30% to 10%, The limits of detection(LOD)values for Cu and Cd decreased by 5% and 4%, respectively. Through CF-LIBS, a quantitative analysis was conducted to determine the relative content of elements in soils. Using Cu as a reference, the concentration of Cd was accurately calculated. The results show that post-data filtering, the average relative error of the Cd decreases from 11% to 5%, indicating the effectiveness of data filtering in improving the accuracy of quantitative analysis. Moreover, the content of Si, Fe and other elements can be accurately calculated using this method. To further correct the calculation, the results for Cd was used to provide a more precise calculation. This approach is of great importance for the large-area in-situ heavy metals and trace elements detection in soil, as well as for rapid and accurate quantitative analysis. 展开更多
关键词 laser-induced breakdown spectroscopy soil data filtering quantitative analysis multielement
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Correlation Analysis between Well-cellar Early Transplanting of Robust Seedlings and Diseases in Shiyan Tobacco-growing Area
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作者 Dingjun WANG Aihua LI +4 位作者 Liguang CHAI Dan LIU Yixia LIU Minggang LI Jingyang PENG 《Plant Diseases and Pests》 2024年第4期21-24,36,共5页
[Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship bet... [Objectives]The paper was to investigate the relationship between the well-cellar early transplanting of robust seedlings and the prevalence of diseases in the Shiyan tobacco-growing area.[Methods]The relationship between disease occurrence and meteorological factors during the field growth period was examined by analyzing the prevalence of flue-cured tobacco virus diseases,brown spot,and total disease in the Shiyan tobacco-growing area before(2013-2017)and after(2018-2022)the well-cellar early transplanting of robust tobacco seedlings.[Results]The implementation of a well-cellar early transplanting technique of robust seedlings resulted in a reduction in the average incidence of tobacco virus disease,brown spot,and total disease by 0.83%,8.85%,and 7.91%,respectively,in comparison to the incidence observed prior to early transplanting.These findings suggest that early transplanting can significantly reduce the incidence of flue-cured tobacco diseases.Prior to the well-cellar early transplanting of robust tobacco seedlings,there was a significant(including highly significant)positive correlation between the incidence of brown spot and total disease and precipitation in August and September.The incidence of brown spot and total disease in tobacco plants was found to be significantly positively correlated with May precipitation and significantly negatively correlated with May sunshine hours following the well-cellar early transplanting of robust seedlings.The advancement of the transplanting period by 20 d resulted in a reduction in the growing period of tobacco plants in the field under autumn rains(late August to November)in western China.This effectively circumvented the suitable conditions for disease occurrence and can reduce the incidence of disease.[Conclusions]This study offers a framework for enhancing the quality and efficiency of flue-cured tobacco production in the northwest tobacco-growing area of Hubei. 展开更多
关键词 Tobacco disease Well-cellar early transplanting of robust seedlings Meteorological factor Correlation analysis Shiyan tobacco-growing area
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Analysis of the Fertilizing and Bioremediation Potential of Leaf Litter Compost Amendment in Different Soils through Indexing Method
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作者 Sophayo Mahongnao Pooja Sharma +1 位作者 Arif Ahamad Sarita Nanda 《Journal of Environmental Protection》 2024年第3期265-297,共33页
This research study explored the efficacy of leaf litter compost as a sustainable soil amendment with the objective of promoting soil health and mitigating the accumulation of potentially toxic elements. The investiga... This research study explored the efficacy of leaf litter compost as a sustainable soil amendment with the objective of promoting soil health and mitigating the accumulation of potentially toxic elements. The investigation encompassed the impact of various organic compost amendments, including leaf compost, cow dung manure, kitchen waste compost, municipal organic waste compost, and vermicompost. The study employed Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to evaluate soil nutrient levels and concentrations of Potentially Toxic Elements (PTEs) such as arsenic, chromium, cadmium, mercury, lead, nickel, and lithium. The fertilization and bioremediation potential of these compost amendments are quantified using an indexing method. Results indicated a substantial increase in overall nutrient levels (carbon, nitrogen, phosphorus, potassium, and sulfur) in soils treated with leaf compost and other organic composts. Fertility indices (FI) are notably higher in compost-amended soils (ranging from 2.667 to 3.938) compared to those amended with chemical fertilizers (ranging from 2.250 to 2.813) across all soil samples. Furthermore, the mean concentrations of PTEs were significantly lower in soils treated with leaf compost and other organic compost amendments compared to those treated with chemical fertilizers amendments. The assessment through the indexing method revealed a high clean index (CI) for leaf compost amendment (ranging from 3.407 to 3.58), whereas the chemical fertilizer amendment exhibits a relatively lower CI (ranging from 2.78 to 3.20). Consequently, leaf compost and other organic composts exhibit the potential to enhance sustainable productivity, promoting soil health and environmental safety by improving nutrient levels and remediating potentially toxic elements in the soil. 展开更多
关键词 Bio-Compost soil Fertility Potentially Toxic Elements BIOREMEDIATION
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Physicochemical and Bacteriological Profile of Bilanko and Ngamakala Peat Bog Soils (Republic of Congo)
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作者 Gatsé Elgie Viennechie Mboukou Kimbatsa Irène Marie Cecile +2 位作者 Ignoumba Evariste Mesmin Morabandza Cyr Jonas Nguimbi Etienne 《Journal of Environmental Protection》 2024年第8期842-862,共21页
Peatlands are unique and complex natural ecosystems that are part of the most important carbon reservoirs on our planet, home to a diversity of microorganisms responsible for fermentation, humification or peat. The ai... Peatlands are unique and complex natural ecosystems that are part of the most important carbon reservoirs on our planet, home to a diversity of microorganisms responsible for fermentation, humification or peat. The aim is to understand chemical and biological indicators of peatland soils. This work aims to determine the physicochemical and bacteriological profile and lipolytic activity of soil bacteria in Bilanko peatlands. The bacterial profile with the production of lipases is carried out by classical microbiology techniques. The results show that the soils are moderately acidic with temperatures of 27.8˚C ± 0.01˚C for Bilanko and 27.1˚C ± 0.57˚C for Ngamakala. The electroconductivity (EC) varies from (9.52 ± 0.002) μS/cm to (39.01 ± 1.4) μS/cm with low turbidity of (2.04 ± 0.66) mg/L to (31.02 ± 0.84) mg/L and low ion concentrations with, however, a richness in phenolic compounds for Bilanko compared to Ngamakala. FMAT diversity ranged from (1.71 ± 0.88)∙104 UFC/g to (2.92 ± 0.07)∙105 UFC/g for Bilanko and (1.30 ± 0.73)∙104 UFC/g to (2.89 ± 0.06)∙104 UFC/g for Ngamakala. Bacillus loads ranged from (5.20 ± 1.40)∙103 CFU/g to (1.22 ± 0.13)∙104 CFU/g and from (1.11 ± 0.13)∙104 CFU/g to (9.20 ± 2.05)∙103 CFU/g;enterobacteria loads from (1.40 ± 0.76)∙103 CFU/g to (8.80 ± 1.73)∙103 CFU/g and from (1.01 ± 0.02)∙103 CFU/g to (9.20 ± 2.05)∙103 CFU/g;in Pseudomonas from 0 to (2.30 ± 0.53)∙102 CFU/g and from 0 to (8.90 ± 2.35)∙102 CFU/g for Bilanko and Ngamakala respectively. These results reveal a variation in bacterial similarity and distribution in the Bilanko and Ngamakala peat bogs. 展开更多
关键词 BACTERIA LIPASE POLYPHENOL soil Peat Bog Republic of Congo
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