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Combined application of a straw layer and flue gas desulphurization gypsum to reduce soil salinity and alkalinity 认领
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作者 Yonggan ZHAO Yan LI +2 位作者 Shujuan WANG Jing WANG Lizhen XU 《土壤圈:英文版》 SCIE CAS CSCD 2020年第2期226-235,共10页
Burying a straw layer and applying flue gas desulphurization(FGD)gypsum are effective practices to ameliorate soil salinization or alkalization and to increase crop yield;however,little information exists on the effec... Burying a straw layer and applying flue gas desulphurization(FGD)gypsum are effective practices to ameliorate soil salinization or alkalization and to increase crop yield;however,little information exists on the effects of such integration in saline-alkali soils.A soil column experiment was conducted to investigate the effects of a straw layer plus FGD gypsum on soil salinity and alkalinity.We placed a straw layer(5 cm thick)at a depth of 30 cm and mixed FGD gypsum into the 0–20 cm soil layer at application rates of 7.5,15.0,22.5,and 30.0 t ha^-1,with no straw layer and FGD gypsum as a control(CK).The soil water content in the 0–30 cm soil layer was significantly higher(>7.8%)in the treated soil profiles after infiltration than in the CK,but decreased after evaporation.The electrical conductivity(EC)of the 10–30 cm soil layer was 230.2%and 104.9%higher in the treated soil profiles than in the CK after infiltration and evaporation,respectively,and increased with increasing rates of FGD gypsum application,with Ca^2+and SO4^2-being the main dissolved salts.Compared to those in the CK,the concentrations of Na^+,Cl^-,and HCO3-decreased in the treated soil profiles at depths above 55 cm,but the other soluble ions increased,after infiltration.A similar trend occurred after evaporation for all soluble ions except for HCO3-.The p H and exchangeable sodium percentage in the treated soil profiles were significantly lower than those in the CK over the entire profile,and decreased with increasing FGD gypsum application rates.Therefore,the incorporation of a straw layer plus FGD gypsum can reduce salinity and alkalinity,but the quantity of FGD gypsum should be controlled in saline-alkali soils. 展开更多
关键词 alkaline soil saline-alkali stress saline soil salt accumulation secondary salinization soil amelioration soil reclamation
宜春地区不同地块不同深度的典型土体定名与工程分类研究 认领
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作者 陆有忠 张正奇 徐陈明 《宜春学院学报》 2020年第3期50-54,共5页
对宜春地区不同地块不同深度的几种典型原始土样(非扰动)进行了关于土体定名实验研究,并在此基础上对这几种土样进行了精确的工程分类。本次实验选取了宜春不同地块不同深度的原始土样,首先对这几种土样进行密度测量和孔隙率测量的实验... 对宜春地区不同地块不同深度的几种典型原始土样(非扰动)进行了关于土体定名实验研究,并在此基础上对这几种土样进行了精确的工程分类。本次实验选取了宜春不同地块不同深度的原始土样,首先对这几种土样进行密度测量和孔隙率测量的实验。为了获得精确的实验结果,在尽量不扰动土样的基础上,对每一种土样进行平行测定,最终得出它们不同的密度类别与孔隙率,通过查找与对比各类土的密度理论值,根据孔隙比与孔隙率的数学关系,换算出相应的孔隙比,进而对上述原始土样进行定名与工程分类。通过研究,进一步判断出宜春地区典型土体的物理特性和力学性质,进而为该地区正在进行的棚户区改造项目建设所做的地基处理、基坑开挖与支护、边坡防护支护等提供必要而有意义的理论依据,也达到了科研服务地方经济建设的目的。 展开更多
关键词 宜春地区 土的密度 土的定名 土的工程分类
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Variation in glomalin in soil profiles and its association with climatic conditions,shelterbelt characteristics,and soil properties in poplar shelterbelts of Northeast China 认领
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作者 Qiong Wang Wenjie Wang +2 位作者 Zhaoliang Zhong Huimei Wang Yujie Fu 《林业研究:英文版》 SCIE CAS CSCD 2020年第1期279-290,共12页
Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variati... Glomalin-related soil protein(GRSP)sequesters large amounts of carbon and plays important roles in maintaining terrestrial soil ecosystem functions and ecological restoration;however,little is known about GRSP variation in 1-m soil profiles and its association with stand characteristics,soil properties,and climatic conditions,hindering GRSP-related degraded soil improvement and GRSP evaluation.In this study,we sampled soils from 1-m profiles from poplar(Populus spp.)shelterbelts in Northeast China.GRSP contents were 1.8–2.0 times higher in the upper 40 cm soil layers than at 40–100 cm.GRSP-related soil organic carbon(SOC)sequestration in deeper soil layers was*1.2 times higher than in surface layers.The amounts of GRSP-related nutrients were similar throughout the soil profile.A redundancy analysis showed that in both surface and deeper layers,soil properties(pH,electrical conductivity,water,SOC,and soil nutrients)explained the majority of the GRSP variation(59.5–84.2%);the second-most-important factor in GRSP regulation was climatic conditions(temperature,precipitation,and altitude),while specific shelterbelt characteristics had negligible effects(<5%).Soil depth and climate indirectly affected GRSP features via soil properties,as manifested by structural equation model analysis.Our findings demonstrate that GRSP is important for carbon storage in deep soils,regardless of shelterbelt characteristics.Future glomalin assessments should consider these vertical patterns and possible regulating mechanisms that are related to soil properties and climatic changes. 展开更多
关键词 SOIL depth Glomalin-related SOIL protein(GRSP) SOIL organic carbon storage Climate change SOIL improvement
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Method development for estimating soil organic carbon content in an alpine region using soil moisture data 认领
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作者 Qi LUO Kun YANG +1 位作者 Yingying CHEN Xu ZHOU 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2020年第4期591-601,共11页
The high soil organic carbon(SOC) content in alpine meadow can significantly change soil hydrothermal properties and further affect the soil temperature and moisture as well as the surface water and energy budget. The... The high soil organic carbon(SOC) content in alpine meadow can significantly change soil hydrothermal properties and further affect the soil temperature and moisture as well as the surface water and energy budget. Therefore, this study first introduces a parameterization scheme to describe the effect of SOC content on soil hydraulic and thermal parameters in a land surface model(LSM), and then the SOC content is estimated by minimizing the difference between observed and simulated surface-layer soil moisture. The accuracy of the estimated SOC content was evaluated using in situ observation data at a soil moisture and temperature-measuring network in Naqu, central Tibetan Plateau. Sensitivity experiments show that the optimum time window for stabilizing the estimation results cannot be shorter than three years. In the experimental area, the estimated SOC content can generally reflect the spatial distribution of the measurements, with a root mean square error of 0.099 m~3 m~(-3), a mean bias of 0.043 m~3 m~(-3), and a correlation coefficient of 0.695. The estimated SOC content is not sensitive to the temporal frequency of the soil moisture data input. Even if the temporal frequency is as low as that of current soil moisture products derived from passive microwave satellites, the estimation result is still stable. Therefore, by combining a high-quality satellite soil moisture product and a parameter optimization method, it is possible to obtain grid-scale effective parameter values, such as SOC content,for an LSM and improve the simulation ability of the LSM. 展开更多
关键词 LAND surface model SOIL organic carbon content SOIL POROSITY SOIL PARAMETER estimation
Research Progress on the Effect of Biochar on Soil Organic Carbon 认领
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作者 Shuhong LIU 《农业生物技术:英文版》 CAS 2020年第2期79-81,共3页
Soil organic carbon has been identified as one of the most important components in soil.Changes in soil organic carbon content will significantly affect atmospheric CO2 concentration,which is related to soil fertility... Soil organic carbon has been identified as one of the most important components in soil.Changes in soil organic carbon content will significantly affect atmospheric CO2 concentration,which is related to soil fertility,water holding capacity,nutrient cycling,and changes in microbial communities.In recent years,biochar has been proven to be an effective material for increasing carbon storage,and research on the application of biochar in soil ecosystem carbon sequestration and emission reduction functions has received widespread attention.However,due to differences in the specific methods and research objects used in the research process,the current mechanism of the impact of biochar on soil organic carbon is still controversial.This paper mainly revealed the effects of biochar on soil organic carbon from the aspects of the effects of biochar addition on soil aggregates and microorganisms,and also elaborated on the direction worth exploring and objectively evaluated the impact mechanism of biochar on soil organic carbon. 展开更多
关键词 BIOCHAR SOIL ORGANIC carbon SOIL AGGREGATE SOIL MICROORGANISMS
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Effects of reduced nitrogen and suitable soil moisture on wheat(Triticum aestivum L.) rhizosphere soil microbiological,biochemical properties and yield in the Huanghuai Plain,China 认领
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作者 ZHOU Su-mei ZHANG Man +4 位作者 ZHANG Ke-ke YANG Xi-wen HE De-xian YIN Jun WANG Chen-yang 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第1期234-250,共17页
Soil management practices affect rhizosphere microorganisms and enzyme activities, which in turn influence soil ecosystem processes. The objective of this study was to explore the effects of different nitrogen applica... Soil management practices affect rhizosphere microorganisms and enzyme activities, which in turn influence soil ecosystem processes. The objective of this study was to explore the effects of different nitrogen application rates on wheat(Triticum aestivum L.) rhizosphere soil microorganisms and enzyme activities, and their temporal variations in relation to soil fertility under supplemental irrigation conditions in a fluvo-aquic region. For this, we established a split-plot experiment for two consecutive years(2014–2015 and 2015–2016) in the field with three levels of soil moisture: water deficit to no irrigation(W1), medium irrigation to(70±5)% of soil relative moisture after jointing stage(W2), and adequate irrigation to(80±5)% of soil relative moisture after jointing stage(W3);and three levels of nitrogen: 0 kg ha^–1(N1), 195 kg ha^–1(N2) and 270 kg ha^–1(N3). Results showed that irrigation and nitrogen application significantly increased rhizosphere microorganisms and enzyme activities. Soil microbiological properties showed different trends in response to N level;the highest values of bacteria, protease, catalase and phosphatase appeared in N2, while the highest levels of actinobacteria, fungi and urease were observed in N3. In addition, these items performed best under medium irrigation(W2) relative to W1 and W3;particularly the maximum microorganism(bacteria, actinobacteria and fungi) amounts appeared at W2, 5.37×10^7 and 6.35×10^7 CFUs g^–1 higher than those at W3 in 2014–2015 and 2015–2016, respectively;and these changes were similar in both growing seasons. Microbe-related parameters fluctuated over time but their seasonality did not hamper the irrigation and fertilization-induced effects. Further, the highest grain yields of 13 309.2 and 12 885.7 kg ha^–1 were both obtained at W2 N2 in 2014–2015 and 2015–2016, respectively. The selected properties, soil microorganisms and enzymes, were significantly correlated with wheat yield and proved to be valuable indicators of soil qualit 展开更多
关键词 suitable SOIL moisture nitrogen-reduction RHIZOSPHERE SOIL microorganisms RHIZOSPHERE SOIL enzyme activity winter wheat(Triticum AESTIVUM L.)
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土壤污染现状及治理措施 认领
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作者 沈颖辉 《云南化工》 CAS 2020年第1期150-152,共3页
阐述了土壤污染的特征、危害和现状,并从物理修复、化学修复和生物修复三方面简要介绍了土壤修复措施,旨在为土壤修复提供科学依据。
关键词 土壤污染 修复技术
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Human and ecological risks of metals in soils under different land-use types in an urban environment of Bangladesh 认领
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作者 Md.Saiful ISLAM Md.Kawser AHMED +1 位作者 Md.Habibullah Al-MAMUN Dennis Wayne EATON 《土壤圈:英文版》 SCIE CAS CSCD 2020年第2期201-213,共13页
Trace metal contamination in soil is of great concern owing to its long persistence in the environment and toxicity to humans and other organisms.Concentrations of six potentially toxic trace metals,Cr,Ni,Cu,As,Cd,and... Trace metal contamination in soil is of great concern owing to its long persistence in the environment and toxicity to humans and other organisms.Concentrations of six potentially toxic trace metals,Cr,Ni,Cu,As,Cd,and Pb,in urban soils were measured in Dhaka City,Bangladesh.Soils from different land-use types,namely,agricultural field,park,playground,petrol station,metal workshop,brick field,burning sites,disposal sites of household waste,garment waste,electronic waste,and tannery wast,and construction waste demolishing sites,were investigated.The concentration ranges of Cr,Ni,Cu,As,Pb,and Cd in soils were 2.4–1258,8.3–1044,9.7–823,8.7–277,1.8–80,and 13–842 mg kg^-1,respectively.The concentrations of metals were subsequently used to establish hazard quotients(HQs)for the adult population.The metal HQs decreased in the order of As>Cr>Pb>Cd>Ni>Cu.Ingestion was the most vital exposure pathway of studied metals from soils followed by dermal contact and inhalation.The range of pollution load index(PLI)was 0.96–17,indicating severe contamination of soil by trace metals.Considering the comprehensive potential ecological risk(PER),soils from all land-use types showed considerable to very high ecological risks.The findings of this study revealed that in the urban area studied,soils of some land-use types were severely contaminated with trace metals.Thus,it is suggested that more attention should be paid to the potential health risks to the local inhabitants and ecological risk to the surrounding ecosystems. 展开更多
关键词 hazard quotient health risk land use potential ecological risk soil pollution trace metals urban soil
Soil aggregation and aggregate-associated organic carbon under typical natural halophyte communities in arid saline areas of Northwest China 认领
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作者 Zhibo CHENG Jingya WANG +2 位作者 William JGALE Haichang YANG Fenghua ZHANG 《土壤圈:英文版》 SCIE CAS CSCD 2020年第2期236-243,共8页
Information on the effects of halophyte communities on soil organic carbon(SOC)is useful for sequestrating C in arid regions.In this study,we identified four typical natural halophyte communities in the Manasi River B... Information on the effects of halophyte communities on soil organic carbon(SOC)is useful for sequestrating C in arid regions.In this study,we identified four typical natural halophyte communities in the Manasi River Basin in Xinjiang Province,Northeast China,namely,Karelinia caspia(Pall.)Less.,Bassia dasyphylla(Fisch.et C.A.Mey.)Kuntze,Haloxylon ammodendron(C.A.Mey.)Bunge,and Tamarix ramosissima Lour.We compared soil aggregation and aggregated-associated SOC under these communities.The aggregate fraction of 0.053–0.25 mm accounted for 47%–75%of the total soil mass,significantly more than the>0.25 and<0.053 mm fractions,under all the halophyte communities.Significant differences in soil aggregate size distribution were observed among the plant communities,with the H.ammodendron and B.dasyphylla communities showing the highest proportions of>0.25 mm aggregates(13.3%–43.8%)and T.ramosissima community having more<0.053 mm aggregates(14.1%–27.2%).Aggregate-associated SOC concentrations were generally the highest in the>0.25 mm fraction,followed by the<0.053 mm fraction,and were the lowest in the 0.053–0.25 mm fraction;however,because of their large mass,0.25–0.053 mm aggregates contributed significantly more to the total SOC.Total SOC concentrations(0–60 cm depth)decreased in the order of H.ammodendron(5.7 g kg^-1)>T.ramosissima(4.9 g kg^-1)>K.caspia(4.2 g kg^-1)>B.dasyphylla(3.4 g kg^-1).The H.ammodendron community had the highest total SOC and aggregate-associated SOC,which was primarily because aggregate-associated SOC content at the 0–10 and 10–20 cm depths under this community were higher than those under other plant communities.The H.ammodendron community could be beneficial for increasing SOC in saline soils in the arid region. 展开更多
关键词 arid regions C sequestration soil aggregates soil organic C saline soils
Composition and Diversity of Soil Bacterial Communities along an Environmental Gradient in the Sudano-Sahelian Region of Senegal 认领
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作者 Souleymane B. D. Diatta Laure N. Tall +2 位作者 Yacine B. Ndour Mbacke Sembene Komi Assigbetsé 《土壤科学期刊(英文)》 2020年第2期58-89,共32页
The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorga... The soils of the semi-arid Sudano-Sahelian region of West Africa have been identified as being highly vulnerable to soil degradation with impacts on their capacity to provide goods and services in which soil microorganisms participate. Unfortunately, soil microbial diversity from this semi-arid region with high rainfall variability remains largely unexplored. The aim of the present study was to characterize the diversity and composition of the soil bacterial communities and to identify factors involved in their spatial distribution along an environmental gradient in Senegal. Samples were collected from non-anthropogenic sites across four pedoclimatic zones. Bacterial communities were characterized using next-generation sequencing and soil physico-chemical parameters were determined. Our results showed that Firmicutes, Actinobacteria, Proteobacteria, Chloroflexi, Gemmatimonadetes, Acidobacteria, and Verrucomicrobia phyla were predominant in the soils of the region. Bacterial α-diversity was stable along the environmental gradient whereas β-diversity highlighted significant changes in the composition of the soil bacterial community. Changes were driven by shifts in the relative abundance of OTUs belonging mainly to the genus Bacillus, Conexibacter, Kaistobacter, Solirubrobacter, Ktedonobacter, Sphingomonas, Microvirga, Rubrobacter and Pelobacter. Soil properties like pH, soil moisture and clay content were the environmental parameters identified as drivers of the composition of the bacterial communities in the semi-arid Sudano-Sahelian region of Senegal (West Africa). 展开更多
关键词 SOIL Bacterial DIVERSITY Sudano-Sahelian Pedoclimatic Gradient Next-Generation SEQUENCING
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Effect of soil pore size distribution on plant-available water and least limiting water range as soil physical quality indicators 认领
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作者 Mehdi ZANGIABADI Manoochehr GORJI +2 位作者 Mehdi SHORAFA Saeed KHAVARI KHORASANI Saeed SAADAT 《土壤圈:英文版》 SCIE CAS CSCD 2020年第2期253-262,共10页
Soil pore size distribution(SPSD) is one of the most important soil physical properties. This research investigated the relationships of location and shape parameters of the SPSD curves with plant-available water(PAW)... Soil pore size distribution(SPSD) is one of the most important soil physical properties. This research investigated the relationships of location and shape parameters of the SPSD curves with plant-available water(PAW) and least limiting water range(LLWR) of the light-textured soils at the Torogh Agricultural Research Station in north-eastern Iran. Soil moisture release curve(SMRC), PAW and LLWR in matric heads of 100 and 330 h Pa for the field capacity and location and shape parameters of the SPSD curves of 30 soils with different texture and organic carbon contents were determined, and the variable relationships were statistically analyzed. The results showed that the median equivalent pore diameter(de), mean de, standard deviation(SD*), and skewness of the SPSD curves were significantly correlated with PAW(PAW330) and LLWR(LLWR330) measured in a matric head of 330 h Pa. Decrease in deand increase in the diversity of soil pore size(SD*) increased PAW330 and LLWR330. The SD* values of all the soil samples were lower than the optimal ranges suggested in literature. Neither PAW nor LLWR values were significantly different in the soils with the optimal modal deand those with non-optimal modal de. Optimal values of median and mean equivalent pore diameters and kurtosis of SPSD curves led to a significant improvement of PAW330 and LLWR330 as soil physical quality indicators. It was recommended to revise the optimal ranges for SD* and modal defor future studies. 展开更多
关键词 equivalent pore diameter KURTOSIS location parameter matric head shape parameter SKEWNESS soil pore size distribution curve soil water availability
浅析土壤中氡浓度检测及其影响因素 认领
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作者 庞观华 《广东化工》 CAS 2020年第2期139-139,157共2页
氡气是一种无味无色的放射性气体,其如果存在人们的生活和工作环境中,会对人们的身体健康造成危害。相关调查结果表明,人如果长期接受高浓度的氡气照射,患肺癌的几率明显更高。因此,在建筑工程建设中,如果工程所在区域内的氡气的含量过... 氡气是一种无味无色的放射性气体,其如果存在人们的生活和工作环境中,会对人们的身体健康造成危害。相关调查结果表明,人如果长期接受高浓度的氡气照射,患肺癌的几率明显更高。因此,在建筑工程建设中,如果工程所在区域内的氡气的含量过高,则会造成建筑工程内低层内的氡浓度偏高,这会对人们的健康造成较为严重的影响。下面,首先介绍了检测土壤中氡浓度的方法及原则;其次,对检测土壤中氡浓度的实例分析进行了阐述;最后,总结了影响土壤中氡浓度检测质量的各项因素。 展开更多
关键词 土壤 氡气 干燥剂 土壤湿度
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Instrumental Characterization of Pretoria Clay Soil by XRF, XRD and SEM 认领
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作者 Adeyinka Olaseinde Mxolisi Brendon Shongwe +1 位作者 Joseph Babalola Adeshina Luqman Adisa 《矿物质和材料特性和工程(英文)》 2020年第1期1-8,共8页
The products of refractory materials are used for lining furnace, incinerators and kilns among other uses and they have the potential of withstanding high temperature without deformation. The objective of the research... The products of refractory materials are used for lining furnace, incinerators and kilns among other uses and they have the potential of withstanding high temperature without deformation. The objective of the research was to charac-terize the clay soil sample collected from Tshwane University of Technology in Pretoria. The sample, collected from a location Latitude 25.0969°S and Longi-tude 28.1624°E, was oven-dried, pulverized and sieved in the laboratory. Min-eralogical and elemental compositions of the sample were determined by using X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF) and Scanning Electron Microscopy (SEM) analytical methods. The XRF analysis revealed Fe2O3, Al2O3 and SiO2 as the major constituents, while the other elements occur in minor quantities. Mineralogically, the three samples contain Montmorillonite, Kaolinite and Bentonite, while Samples A contained Quartz in addition to ear-lier mentioned minerals, samples B and C contained Albite. 展开更多
关键词 CHARACTERIZATION Clay MINERALS Soil XRD XRF SEM
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Validation and correction of sea surface salinity retrieval from SMAP 认领
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作者 Sisi Qin Hui Wang +3 位作者 Jiang Zhu Liying Wan Yu Zhang Haoyun Wang 《海洋学报:英文版》 SCIE CAS CSCD 2020年第3期148-158,共11页
In this study, sea surface salinity(SSS) Level 3(L3) daily product derived from soil moisture active passive(SMAP)during the year 2016, was validated and compared with SSS daily products derived from soil Moisture and... In this study, sea surface salinity(SSS) Level 3(L3) daily product derived from soil moisture active passive(SMAP)during the year 2016, was validated and compared with SSS daily products derived from soil Moisture and ocean salinity(SMOS) and in-situ measurements. Generally, the root mean square error(RMSE) of the daily SSS products is larger along the coastal areas and at high latitudes and is smaller in the tropical regions and open oceans. Comparisons between the two types of daily satellite SSS product revealed that the RMSE was higher in the daily SMOS product than in the SMAP, whereas the bias of the daily SMOS was observed to be less than that of the SMAP when compared with Argo floats data. In addition, the latitude-dependent bias and RMSE of the SMAP SSS were found to be primarily influenced by the precipitation and the sea surface temperature(SST). Then, a regression analysis method which has adopted the precipitation and SST data was used to correct the larger bias of the daily SMAP product. It was confirmed that the corrected daily SMAP product could be used for assimilation in high-resolution forecast models, due to the fact that it was demonstrated to be unbiased and much closer to the in-situ measurements than the original uncorrected SMAP product. 展开更多
关键词 sea surface salinity(SSS) SOIL MOISTURE active passive(SMAP) SOIL MOISTURE and ocean salinity(SMOS) VALIDATION CORRECTION
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Ridge-furrow plastic mulching with a suitable planting density enhances rainwater productivity,grain yield and economic benefit of rainfed maize 认领
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作者 ZHENG Jing FAN Junliang +2 位作者 ZOU Yufeng Henry Wai CHAU ZHANG Fucang 《干旱区科学:英文版》 SCIE CSCD 2020年第2期181-198,共18页
Soil surface mulching and planting density regulation are widely used for effective utilization of limited rainwater resources and improvement of crop productivity in dryland farming.However,the combined effects of mu... Soil surface mulching and planting density regulation are widely used for effective utilization of limited rainwater resources and improvement of crop productivity in dryland farming.However,the combined effects of mulching type and planting density on maize growth and yield have been seldom studied,especially in different hydrological years.A field experiment was conducted to evaluate the effects of mulching type and planting density on the soil temperature,growth,grain yield(GY),water use efficiency(WUE)and economic benefit of rainfed maize in the drylands of northern China during 2015-2017.Precipitation fluctuated over the three years.There were four mulching types(NM,flat cultivation with non-mulching;SM,flat cultivation with straw mulching;RP,plastic-mulched ridge plus bare furrow;RPFS,plastic-mulched ridge plus straw-mulched furrow)and three planting densities(LD,low planting density,45.0×10^3 plants/hm^2;MD,medium planting density,67.5×10^3 plants/hm^2;HD,high planting density,90.0×10^3 plants/hm^2).Results showed that soil temperature was higher with RP and lower with SM compared with NM,but no significant difference was found between RPFS and NM.More soil water was retained by soil mulching at the early growth stage,but it significantly varied at the middle and late growth stages.Maize growth was significantly improved by soil mulching.With increasing planting density,stem diameter,net photosynthetic rate and chlorophyll content tended to decline,whereas a single-peak trend in biomass yield was observed.Mulching type and planting density did not have significant effect on evapotranspiration(ET),but GY and WUE were significantly affected.There were significant interacting effects of mulching type and planting density on biomass yield,GY,ET and WUE.Compared with NM,RPFS,RP and SM increased GY by 57.5%,50.8%and 18.9%,and increased WUE by 66.6%,54.3%and 18.1%,respectively.At MD,GY increased by 41.4%and 25.2%,and WUE increased by 38.6%and 22.4%compared with those of at LD and HD.The highest maize GY(7023.2 展开更多
关键词 dryland farming EVAPOTRANSPIRATION net income soil temperature soil water storage
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Wildfire effects on permafrost and soil moisture in spruce forests of Interior Alaska 认领
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作者 Christopher Potter Charles Hugny 《林业研究:英文版》 SCIE CAS CSCD 2020年第2期553-563,共11页
In the summer of 2015,hundreds of forest fires burned across the state of Alaska.Several uncontrolled wildfires near the town of Tanana on the Yukon River were responsible for the largest portion of the area burned st... In the summer of 2015,hundreds of forest fires burned across the state of Alaska.Several uncontrolled wildfires near the town of Tanana on the Yukon River were responsible for the largest portion of the area burned statewide.In July 2017,field measurements were carried out in both unburned and burned forested areas nearly adjacent to one another,all within 15 miles of the village of Tanana.These surveys were used to first visually verify locations of different burn severity classes,(low,moderate,or high),estimated in 2016 from Landsat images(collected before and after the 2015 Tanana-area wildfires).Surface and soil profile measurements to 30-cm depth at these same locations were collected for evidence of moss layer and forest biomass burning.Soil temperature and moisture content were measured to 30-cm depth,and depth to permafrost was estimated by excavation wherever necessary.Digital thermal infra-red images of the soil profiles were taken at each site location,and root-zone organic layer samples were extracted for further chemical analysis.Results supported the hypothesis that the loss of surface organic layers is a major factor determining post-fire soil water and temperature changes and the depth of permafrost thawing.In the most severely burned forest sites,complete consumption of the living moss organic layer was strongly associated with both warming at the surface layer and increases in soil water content,relative to unburned forest sites.Soil temperatures at both 10-cm and 30-cm depths at burned forest sites were higher by 8–10 ℃ compared to unburned sites.Below 15 cm,temperatures of unburned sites dropped gradually to frozen levels by 30 cm,while soil temperatures at burned sites remained above 5 ℃ to30-cm depth.The water content measured at 3 cm at burned sites was commonly in excess of 30% by volume,compared to unburned sites.The strong correlation between burn index values and depth to permafrost measured across all sites sampled in July 2017 showed that the new ice-free profile in severely bur 展开更多
关键词 Alaska LANDSAT PERMAFROST RdNBR SOIL temperature SOIL water WILDFIRE
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Evaluation of soil flame disinfestation(SFD) for controlling weeds,nematodes and fungi 认领
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作者 WANG Xiao-ning CAO Ao-cheng +8 位作者 YAN Dong-dong WANG Qian HUANG Bin ZHU Jia-hong WANG Qiu-xia LI Yuan OUYANG Can-bin GUO Mei-xia WANG Qian 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第1期164-172,共9页
Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly a... Soil flame disinfestation(SFD) is a form of physical disinfestation that can be used both in greenhouses and on field crops. Its use for soil disinfestation in different crop growing conditions makes it increasingly attractive for controlling soilborne pathogens and weeds. But little is known about the effect on weeds and soilbrone diseases. This study reports on greenhouses and field crops in China that determined the efficacy of SFD to control weeds, nematodes and fungi. It also determined the impact of SFD on the soil physical and chemical properties(water content, bulk density, NO3^–-N content, NH4^+-N content, conductivity and organic matter) in three field trials. A second generation SFD machine was used in these trials. SFD treatment significantly reduced weeds(>87.8%) and root-knot nematodes(Meloidogyne incognita)(>98.1%). Plant height and crop yield was significantly increased with SFD treatment. NO3^–-N and NH4^+-N increased after the SFD treatment, and there was also an increase in soil conductivity. Water content, bulk density and organic matter decreased significantly in the soil after the SFD treatment compared to the control. Soil flame disinfestation is a potential technique for controlling weeds and diseases in greenhouses or in fields. SFD is a non-chemical, safe, environmentally-friendly soil disinfection method. 展开更多
关键词 SOIL FLAME DISINFESTATION WEEDS PESTS control SOIL properties field application sustainable
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氮、硫及氮硫交互对土壤酶活性的影响 认领
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作者 严焕焕 耿贵工 +2 位作者 乔枫 韩燕 孙小凤 《青海大学学报》 2020年第2期20-25,共6页
为了研究氮、硫及氮硫交互条件下土壤酶活性的变化,以春油菜种植土壤为供试土样,采用二因素、四水平完全随机设计方案,分析不同施氮量和不同施硫量处理对土壤酶活性的影响程度。结果显示:N3、S5处理,其脲酶活性显著高于对照(P<0.05),... 为了研究氮、硫及氮硫交互条件下土壤酶活性的变化,以春油菜种植土壤为供试土样,采用二因素、四水平完全随机设计方案,分析不同施氮量和不同施硫量处理对土壤酶活性的影响程度。结果显示:N3、S5处理,其脲酶活性显著高于对照(P<0.05),以N5S3处理脲酶活性最高;N1,3处理,土壤蔗糖酶活性较对照显著降低(P<0.05),但交互条件下N5S5处理蔗糖酶活性最高;当施氮量为N1,土壤碱性磷酸酶活性最高,施硫量为S3时,土壤碱性磷酸酶活性显著高于对照(P<0.05),交互作用以N3S3处理碱性磷酸酶活性最高。因此,单因素处理下,当施硫量为13.3-26.6 mg/kg时对土壤脲酶和碱性磷酸酶活性有明显促进作用,但抑制土壤蔗糖酶活性;氮硫交互条件下,高氮(N5)和中硫(S3)交互有利于土壤酶活性的提高。 展开更多
关键词 土壤 氮硫交互 土壤酶活性
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根系土在土壤环境研究中的应用 认领
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作者 田娜 彭秀红 《当代化工研究》 2020年第5期151-152,共2页
随着工农业生产的发展,土壤环境问题日益严峻,据2014年的《全国土地污染状况调查公报》显示,全国耕地土壤的超标率为19.4%,其中的主要污染物为镉、镍、铜、砷、汞、铅等重金属元素,重金属污染问题亟待解决。在土壤环境研究中,根系土作... 随着工农业生产的发展,土壤环境问题日益严峻,据2014年的《全国土地污染状况调查公报》显示,全国耕地土壤的超标率为19.4%,其中的主要污染物为镉、镍、铜、砷、汞、铅等重金属元素,重金属污染问题亟待解决。在土壤环境研究中,根系土作为一项重要的研究对象,对土壤环境研究尤其是农作物土壤具有重要意义。 展开更多
关键词 土壤 环境 根系土
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Research progress on the soil vapor extraction 认领
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作者 GUO Hao QIAN Yong +1 位作者 YUAN Guang-xiang WANG Chun-xiao 《地下水科学与工程:英文版》 2020年第1期57-66,共10页
Soil vapor extraction (SVE), the most common, efficient and economical means of remediation, is an in-situ remediation technique for removing volatile pollutants from unsaturated soil. The paper brie fly introduced th... Soil vapor extraction (SVE), the most common, efficient and economical means of remediation, is an in-situ remediation technique for removing volatile pollutants from unsaturated soil. The paper brie fly introduced the technological rationale and characteristics, summarized the theories and application research for SVE at home and abroad, and made the expectations and suggestions for the research on SVE. The international scholars have systematically researched the influence factors, remediation mechanism and numerical simulation of SVE. At present, SVE has been mostly integrated with other techniques to form enhanced SVE techniques, such as thermally enhanced SVE and AS-SVE (Air sparging- SVE), to be used for the field remediation widely. Compared with foreign countries, researches of Chinese scholars mainly focus on the laboratory research, especially on the influence factors, but rarely study the SVE model and the mass transfer mechanism of pollutant in SVE process. The SVE pilot studies are rare in China, and the field application has not been reported. In view of this situation, Chinese scholars in the future research can focus on the following aspects: (1) strengthening the research and systematized summary of SVE technical parameters and related knowledge;(2) strengthening the research on the mechanism and model of gas-phase mass transfer of pollutants in soil during SVE process;(3) strengthening the research on the enhanced SVE techniques and its application to actual site remediation. 展开更多
关键词 SOIL vapor extraction(SVE) In SITU REMEDIATION ORGANIC POLLUTION SOIL REMEDIATION
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