Area G perimeter surface-soil and single-stage water sampling: Environmental surveillance for fiscal year 95. Progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Childs, M.; Conrad, R.

1997-09-01

ESH-19 personnel collected soil and single-stage water samples around the perimeter of Area G at Los Alamos National Laboratory (LANL) during FY 95 to characterize possible radionuclide movement out of Area G through surface water and entrained sediment runoff. Soil samples were analyzed for tritium, total uranium, isotopic plutonium, americium-241, and cesium-137. The single-stage water samples were analyzed for tritium and plutonium isotopes. All radiochemical data was compared with analogous samples collected during FY 93 and 94 and reported in LA-12986 and LA-13165-PR. Six surface soils were also submitted for metal analyses. These data were included with similar data generatedmore » for soil samples collected during FY 94 and compared with metals in background samples collected at the Area G expansion area.« less

Influence of ore processing activity on Hg, As and Sb contamination and fractionation in soils in a former mining site of Monte Amiata ore district (Italy).

PubMed

Protano, Giuseppe; Nannoni, Francesco

2018-05-01

A geochemical study was carried out at the former Abbadia San Salvatore (ASS) mining site of the Monte Amiata ore district (Italy). Hg, As and Sb total contents and fractionation using a sequential extraction procedure were determined in soil and mining waste samples. Ore processing activities provided a different contribution to Hg contamination and concentration in soil fractions, influencing its behaviour as volatility and availability. Soils of roasting zone showed the highest Hg contamination levels mainly due to the deposition of Hg released as Hg 0 by furnaces during cinnabar roasting. High Hg contents were also measured in waste from the lower part of mining dump due to the presence of cinnabar. The fractionation pattern suggested that Hg was largely as volatile species in both uncontaminated and contaminated soils and mining waste, and concentrations of these Hg species increased as contamination increased. These findings were in agreement with the fact that the ASS mining site is characterized by high Hg concentrations in the air and the presence of Hg 0 liquid droplets in soil. Volatile Hg species were also prevalent in uncontaminated soils likely because the Monte Amiata region is an area characterized by anomalous fluxes of gaseous Hg from natural and anthropogenic inputs. At the ASS mining site soils were also contaminated by Sb, while As contents were comparable with its local background in soil. In all soil and waste samples Sb and As were preferentially in residual fraction. Copyright © 2018 Elsevier Ltd. All rights reserved.

Soils of Low-Mountain Landscapes of North Karelia

NASA Astrophysics Data System (ADS)

Medvedeva, M. V.; Akhmetova, G. V.; Fedorets, N. G.; Yakovlev, A. S.; Raevskii, B. V.; Travin, V. V.

2018-02-01

Soils of low-mountain landscapes in the northwest of Karelia have been studied. The soil cover of the studied area is mainly represented by Al-Fe-humus soils (Podzols); thin soils (Leptosols) are widespread. Characteristic morphological features of all the studied soils are relatively shallow profiles, high stone content, and underlying by hard bedrock with fine earth material in crevices between large boulders. The studied soils have the high carbon and low nitrogen content, which points to unfavorable conditions of organic matter transformation. The content of most macro- and microelements is not high, which is typical for soils of the region; the content of copper and zinc exceeds the regional background two-three times. Regularities of the vertical zonality in the properties of soils of mountain ecosystems manifest themselves in decreasing thickness of the soil profile at higher altitude above sea level in parallel to decreasing thickness of the layer of loose rocks, while the stone content increases. In soils of the forest-tundra zone, the organomineral horizon with the high organic matter content is formed immediately under the forest litter. The litter horizon is the soils of this zone is characterized by increased concentrations of calcium, magnesium, phosphorus, and zinc.

Reconstruction of climate, soil, and vegetation conditions of the Srubnaya cultural epoch on the basis of kurgan studies in the Cis-Ural forest-steppe of the Republic of Bashkortostan

NASA Astrophysics Data System (ADS)

Prikhod'ko, V. E.; Rohozin, Ye. P.; Chaplygin, M. S.

2016-09-01

The reconstruction of soil, vegetation, and climatic conditions for the Srubnaya cultural epoch (3660 ± 40 (date wood), 3860 ± 120 (bones date) was performed on the basis of palynological and paleosol studies with radiocarbon dating of bones and wood fragments from two kurgans in the Cis-Ural forest-steppe of the Republic of Bashkortostan. Morphological features and chemical properties of the modern background soils, the soils formed on the surface of burial mounds (kurgans), and the soils buried under them were characterized. According to palynological data, the climate of this territory in the period of construction of these kurgans was more humid than the modern climate. The paleovegetation of the Srubnaya epoch was represented by mesophilic herbaceous steppes with a lower participation of xerophytic species as compared to the modern steppe and by small forest groves composed of birch and pine trees with some admixture of lime trees. The temperature conditions were close to those at present, or somewhat cooler, which is evidenced by the lower content of pollen of the broadleaved trees. The modern background soils and the soils buried under the kurgans are classified as thin light loamy typical calcareous chernozems; they have similar morphologies and physicochemical properties. However, the reconstructed organic matter content in the upper 50 cm of the buried paleosols is higher than that in the modern soils. This attests to more favorable climatic conditions during the Srubnaya epoch and is in agreement with palynological data.

Soils: man-caused radioactivity and radiation forecast

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gablin, Vassily

2007-07-01

Available in abstract form only. Full text of publication follows: One of the main tasks of the radiation safety guarantee is non-admission of the excess over critical radiation levels. In Russia they are man-caused radiation levels. Meanwhile any radiation measurement represents total radioactivity. That is why it is hard to assess natural and man-caused contributions to total radioactivity. It is shown that soil radioactivity depends on natural factors including radioactivity of rocks and cosmic radiation as well as man-caused factors including nuclear and non-nuclear technologies. Whole totality of these factors includes unpredictable (non-deterministic) factors - nuclear explosions and radiation accidents,more » and predictable ones (deterministic) - all the rest. Deterministic factors represent background radioactivity whose trends is the base of the radiation forecast. Non-deterministic factors represent man-caused radiation treatment contribution which is to be controlled. This contribution is equal to the difference in measured radioactivity and radiation background. The way of calculation of background radioactivity is proposed. Contemporary soils are complicated technologically influenced systems with multi-leveled spatial and temporary inhomogeneity of radionuclides distribution. Generally analysis area can be characterized by any set of factors of soil radioactivity including natural and man-caused factors. Natural factors are cosmic radiation and radioactivity of rocks. Man-caused factors are shown on Fig. 1. It is obvious that man-caused radioactivity is due to both artificial and natural emitters. Any result of radiation measurement represents total radioactivity i.e. the sum of activities resulting from natural and man-caused emitters. There is no gauge which could separately measure natural and man-caused radioactivity. That is why it is so hard to assess natural and man-caused contributions to soil radioactivity. It would have been possible if human activity had led to contamination of soil only by artificial radionuclides. But we can view a totality of soil radioactivity factors in the following way. (author)« less

Natural radioactivity in soils of the state of Rio de Janeiro (Brazil): Radiological characterization and relationships to geological formation, soil types and soil properties.

PubMed

Ribeiro, F C A; Silva, J I R; Lima, E S A; do Amaral Sobrinho, N M B; Perez, D V; Lauria, D C

2018-02-01

Located in the south-western part of Brazil, the state of Rio de Janeiro is geotectonically contained within a complex structural province that resulted in the amalgamation of the Western Gondwana Paleocontinent. To undertake an extensive radiological characterization of this complex geological province and investigate the influence of bedrock, soil type and soil chemical-physical characteristics on natural radionuclide levels in soils, 259 surface soil samples were collected that encompassed the main soil types and geological formations throughout the state. Gamma spectrometry analysis of the samples resulted in median values of 114 Bq.kg -1 for 40 K, 32 Bq.kg -1 for 226 Ra and 74 Bq.kg -1 for 228 Ra. The median value for 226 Ra was similar to the world median value for soils, the 40 K value was well below the worldwide value, and that for 228 Ra exceeded the world median value. The intense weathering caused by the high rainfall rates and high temperatures may be responsible for the low levels of 40 K in the soils, of which the strongly acidic and clayey soils are markedly K-depleted. A soil from a high-grade metamorphic rock (granulite) presented the lowest 226 Ra (18 Bq.kg -1 ) content, whereas the highest levels for 226 Ra (92 Bq.kg -1 ) and 228 Ra (139 Bq.kg - 1) were observed in a young soil enriched in primary minerals (Leptsol). A lowland soil (Gleysol) showed the highest median of 40 K (301 Bq.kg -1 ). Strongly acidic soils tended to present high amounts of 226 Ra, and sandy soils tended to contain low levels of 228 Ra. The external radiation dose indicates that the state has a background radiation level within the natural range. Copyright © 2017 Elsevier Ltd. All rights reserved.

Applicability of radon emanometry in lithologically discontinuous sites contaminated by organic chemicals.

PubMed

De Miguel, Eduardo; Barrio-Parra, Fernando; Elío, Javier; Izquierdo-Díaz, Miguel; García-González, Jerónimo Emilio; Mazadiego, Luis Felipe; Medina, Rafael

2018-06-02

The applicability of radon ( 222 Rn) measurements to delineate non-aqueous phase liquids (NAPL) contamination in subsoil is discussed at a site with lithological discontinuities through a blind test. Three alpha spectroscopy monitors were used to measure radon in soil air in a 25,000-m 2 area, following a regular sampling design with a 20-m 2 grid. Repeatability and reproducibility of the results were assessed by means of duplicate measurements in six sampling positions. Furthermore, three points not affected by oil spills were sampled to estimate radon background concentration in soil air. Data histograms, Q-Q plots, variograms, and cluster analysis allowed to recognize two data populations, associated with the possible path of a fault and a lithological discontinuity. Even though the concentration of radon in soil air was dominated by this discontinuity, the characterization of the background emanation in each lithological unit allowed to distinguish areas potentially affected by NAPL, thus justifying the application of radon emanometry as a screening technique for the delineation of NAPL plumes in sites with lithological discontinuities.

Effects of source rocks, soil features and climate on natural gamma radioactivity in the Crati valley (Calabria, Southern Italy).

PubMed

Guagliardi, Ilaria; Rovella, Natalia; Apollaro, Carmine; Bloise, Andrea; De Rosa, Rosanna; Scarciglia, Fabio; Buttafuoco, Gabriele

2016-05-01

The study, which represents an innovative scientific strategy to approach the study of natural radioactivity in terms of spatial and temporal variability, was aimed to characterize the background levels of natural radionuclides in soil and rock in the urban and peri-urban soil of a southern Italy area; to quantify their variations due to radionuclide bearing minerals and soil properties, taking into account nature and extent of seasonality influence. Its main novelty is taking into account the effect of climate in controlling natural gamma radioactivity as well as analysing soil radioactivity in terms of soil properties and pedogenetic processes. In different bedrocks and soils, activities of natural radionuclides ((238)U, (232)Th (4) K) and total radioactivity were measured at 181 locations by means of scintillation γ-ray spectrometry. In addition, selected rocks samples were collected and analysed, using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS) and an X-Ray Powder Diffraction (XRPD), to assess the main sources of radionuclides. The natural-gamma background is intimately related to differing petrologic features of crystalline source rocks and to peculiar pedogenetic features and processes. The radioactivity survey was conducted during two different seasons with marked changes in the main climatic characteristics, namely dry summer and moist winter, to evaluate possible effects of seasonal climatic variations and soil properties on radioactivity measurements. Seasonal variations of radionuclides activities show their peak values in summer. The activities of (238)U, (232)Th and (4) K exhibit a positive correlation with the air temperature and are negatively correlated with precipitations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Area G Perimeter Surface-Soil Sampling Environmental Surveillance for Fiscal Year 1998 Hazardous and Solid Waste Group (ESH-19)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marquis Childs

1999-09-01

Material Disposal Area G (Area G) is at Technical Area 54 at Los Alamos National Laboratory (LANL). Area G has been the principal facility for the disposal of low-level, solid-mixed, and transuranic waste since 1957. It is currently LANL's primary facility for radioactive solid waste burial and storage. As part of the annual environmental surveillance effort at Area G, surface soil samples are collected around the facility's perimeter to characterize possible radionuclide movement off the site through surface water runoff During 1998, 39 soil samples were collected and analyzed for percent moisture, tritium, plutonium-238 and 239, cesium-137 and americium-241. Tomore » assess radionuclide concentrations, the results from these samples are compared with baseline or background soil samples collected in an undisturbed area west of the active portion Area G. The 1998 results are also compared to the results from analogous samples collected during 1996 and 1997 to assess changes over this time in radionuclide activity concentrations in surface soils around the perimeter of Area G. The results indicate elevated levels of all the radionuclides assessed (except cesium-137) exist in Area G perimeter surface soils vs the baseline soils. The comparison of 1998 soil data to previous years (1996 and 1997) indicates no significant increase or decrease in radionuclide concentrations; an upward or downward trend in concentrations is not detectable at this time. These results are consistent with data comparisons done in previous years. Continued annual soil sampling will be necessary to realize a trend if one exists. The radionuclide levels found in the perimeter surface soils are above background but still considered relatively low. This perimeter surface soil data will be used for planning purposes at Area G, techniques to prevent sediment tm.nsport off-site are implemented in the areas where the highest radionuclide concentrations are indicated.« less

Haemolytic activity of soil from areas of varying podoconiosis endemicity in Ethiopia

PubMed Central

Le Blond, Jennifer S.; Baxter, Peter J.; Bello, Dhimiter; Raftis, Jennifer; Molla, Yordanos B.; Cuadros, Javier; Davey, Gail

2017-01-01

Background Podoconiosis, non-filarial elephantiasis, is a non-infectious disease found in tropical regions such as Ethiopia, localized in highland areas with volcanic soils cultivated by barefoot subsistence farmers. It is thought that soil particles can pass through the soles of the feet and taken up by the lymphatic system, leading to the characteristic chronic oedema of the lower legs that becomes disfiguring and disabling over time. Methods The close association of the disease with volcanic soils led us to investigate the characteristics of soil samples in an endemic area in Ethiopia to identify the potential causal constituents. We used the in vitro haemolysis assay and compared haemolytic activity (HA) with soil samples collected in a non-endemic region of the same area in Ethiopia. We included soil samples that had been previously characterized, in addition we present other data describing the characteristics of the soil and include pure phase mineral standards as comparisons. Results The bulk chemical composition of the soils were statistically significantly different between the podoconiosis-endemic and non-endemic areas, with the exception of CaO and Cr. Likewise, the soil mineralogy was statistically significant for iron oxide, feldspars, mica and chlorite. Smectite and kaolinite clays were widely present and elicited a strong HA, as did quartz, in comparison to other mineral phases tested, although no strong difference was found in HA between soils from the two areas. The relationship was further investigated with principle component analysis (PCA), which showed that a combination of an increase in Y, Zr and Al2O3, and a concurrent increase Fe2O3, TiO2, MnO and Ba in the soils increased HA. Conclusion The mineralogy and chemistry of the soils influenced the HA, although the interplay between the components is complex. Further research should consider the variable biopersistance, hygroscopicity and hardness of the minerals and further characterize the nano-scale particles. PMID:28493920

The change of soil properties after wildfires in drained peatlands (Moscow region, Russia)

NASA Astrophysics Data System (ADS)

Koshovskii, Timur; Tsibart, Anna; Smirnova, Maria; Valentina, Gavrilova; Anna, Kiseleva

2014-05-01

The peat fires differ from the forest and grassland fires, because the soil organic matter acts as burning material. The deep peat horizons are heated or burned during smoldering fires, causing the dramatic change in soil properties. But the most of available data are devoted to changes in organo-mineral soils. In addition, the alteration in hydrological regime, for instance drainage, makes landscapes and soils very vulnerable to wildfires. Drained peatlands are widespread in the European part of Russia and they are affected to extreme wildfires of 2010. So there is a need of post-fire peat soils investigations in this region. During current research the soils of drained peatlands of Moscow Region (Russia) subjected to wildfires of 2002 and 2010 were studied. A total of 14 profiles including background and post-pyrogenic histosols and histic podsols were investigated. Soil samples were taken from genetic horizons and from every 10 cm in cases of thick horizons. The morfological properties of soil profiles were studied and the samples were analysed on macroelements content and organic carbon. The total organic carbon contentrations were detected with spectrofotometric method and the concentrations of macroelements were analysed with X-ray fluorescence method. After wildfires on drained peatlands morfological and physico-chemical properties of soils were changed, the horizons of ash (up to 5 cm) and char (up to 3 cm) instead of organic layers were formed. In addition, the plots of post-pirogenic landscape were characterized by high variability of soil properties. For instance, the thickness of organic layer changed from 5 to 30 cm in a small plot of 5X5 m. The changes in element composition were detected. The peat horizons of background histosols had 80-90% of SiO2, 9-5,8% of Al2O3,1,5-5,6% of Fe2O3, 3,7-6,3% of CaO, 0,7-2,8 % of MnO. Background histic podsols contained 88-90% of SiO2, to 4,8% of Al2O3, and the proportion of Fe2O3 and MnO was about 2,3%. After the fire ash horizons had elevated concentrations of Al2O3 (9-17%), Fe2O3 (4-11%), P2O3 (1-1,8 %), CaO (1,9-2,8 %) and K2O (0,1-1,9%). The char horizons had composition similar to background peat. On the one hand the loss of organic matter took place after burning. But on the other hand after the fire new stage of humus formation started and in 2 years after the burning the content of organic carbon reached up to 10 % in upper horizons.

Geo-Spatial Characterization of Soil Mercury and Arsenic at a High-Altitude Bolivian Gold Mine.

PubMed

Johnson, Glen D; Pavilonis, Brian; Caravanos, Jack; Grassman, Jean

2018-02-01

Soil mercury concentrations at a typical small-scale mine site in the Bolivian Andes were elevated (28-737 mg/kg or ppm) in localized areas where mercury amalgams were either formed or vaporized to release gold, but was not detectable beyond approximately 10 m from its sources. Arsenic was measurable, exceeding known background levels throughout the mine site (77-137,022 ppm), and was also measurable through the local village of Ingenio (36-1803 ppm). Although arsenic levels were high at all surveyed locations, its spatial pattern followed mercury, being highest where mercury was high.

A passive air sampler for characterizing the vertical concentration profile of gaseous phase polycyclic aromatic hydrocarbons in near soil surface air.

PubMed

Zhang, Yuzhong; Deng, Shuxing; Liu, Yanan; Shen, Guofeng; Li, Xiqing; Cao, Jun; Wang, Xilong; Reid, Brian; Tao, Shu

2011-03-01

Air-soil exchange is an important process governing the fate of polycyclic aromatic hydrocarbons (PAHs). A novel passive air sampler was designed and tested for measuring the vertical concentration profile of 4 low molecular weight PAHs in gaseous phase (PAH(LMW4)) in near soil surface air. Air at various heights from 5 to 520 mm above the ground was sampled by polyurethane foam disks held in down-faced cartridges. The samplers were tested at three sites: A: an extremely contaminated site, B: a site near A, and C: a background site on a university campus. Vertical concentration gradients were revealed for PAH(LMW4) within a thin layer close to soil surface at the three sites. PAH concentrations either decreased (Site A) or increased (Sites B and C) with height, suggesting either deposition to or evaporation from soils. The sampler is a useful tool for investigating air-soil exchange of gaseous phase semi-volatile organic chemicals. Copyright © 2010 Elsevier Ltd. All rights reserved.

Hydrocarbon status of soils in the asphalt deposit area (Samara Bend)

NASA Astrophysics Data System (ADS)

Pikovskiy, Yu. I.; Gennadiev, A. N.; Kovach, R. G.; Zhidkin, A. P.; Khlynina, N. I.; Kiseleva, A. Yu.

2017-04-01

The composition and distribution features of the main components of soil hydrocarbon complex― organic (noncarbonate) carbon, hexane bitumoids, and individual polycyclic aromatic hydrocarbons (PAHs)―in the area of depleted Bakhilovo asphalt deposit (Samara oblast) have been studied. According to their proportions, three genetic types of soil hydrocarbon status are distinguished: (a) emanation-injection type prevailing within the limits of the former production field and characterized by anomalous contents of heavy resinous bitumoids (5000-7000 mg/kg on the average) throughout the soil profile and a high content of PAHs (4-9 mg/kg on the average, 29 mg/kg as the maximum, with the dominance of naphthalene homologues); (b) emanation-biogeochemical type confined to mechanogenically undisturbed soils within and beyond the deposit area, where the emanation component is manifested in soils with heavy texture and higher concentrations and very light composition of bitumoids in the lower parts of the soil profile; and (c) atmosedimentation-biogeochemical type characteristic of conventionally background soils with light texture; benzo[ a]pyrene traces are detected among PAHs in the upper soil horizon, which indicates the input of this hydrocarbon with aerosols from the atmosphere; the concentrations of bitumoids and PAHs in parent rocks are lower than in the soils.

Soil Characterization and Site Response of Marine and Continental Environments

NASA Astrophysics Data System (ADS)

Contreras-Porras, R. S.; Huerta-Lopez, C. I.; Martinez-Cruzado, J. A.; Gaherty, J. B.; Collins, J. A.

2009-05-01

An in situ soil properties study was conducted to characterize both site and shallow layer sediments under marine and continental environments. Data from the SCoOBA (Sea of Cortez Ocean Bottom Array) seismic experiment and in land ambient vibration measurements on the urban areas of Tijuana, B. C., and Ensenada, B. C., Mexico were used in the analysis. The goal of this investigation is to identify and to analyze the effect of the physical/geotechnical properties of the ground on the site response upon seismic excitations in both marine and continental environments. The time series were earthquakes and background noise recorded within interval of 10/2005 to 10/2006 in the Gulf of California (GoC) with very-broadband Ocean Bottom Seismographs (OBS), and ambient vibration measurements collected during different time periods on Tijuana and Ensenada urban areas. The data processing and analysis was conducted by means of the H/V Spectral Ratios (HVSPR) of multi component data, the Random Decrement Method (RDM), and Blind Deconvolution (BD). This study presents ongoing results of a long term project to characterize the local site response of soil layers upon dynamic excitations using digital signal processing algorithms on time series, as well as the comparison between the results these methodologies are providing.

A Lipid Extraction and Analysis Method for Characterizing Soil Microbes in Experiments with Many Samples

PubMed Central

Oates, Lawrence G.; Read, Harry W.; Gutknecht, Jessica L. M.; Duncan, David S.; Balser, Teri B.; Jackson, Randall D.

2017-01-01

Microbial communities are important drivers and regulators of ecosystem processes. To understand how management of ecosystems may affect microbial communities, a relatively precise but effort-intensive technique to assay microbial community composition is phospholipid fatty acid (PLFA) analysis. PLFA was developed to analyze phospholipid biomarkers, which can be used as indicators of microbial biomass and the composition of broad functional groups of fungi and bacteria. It has commonly been used to compare soils under alternative plant communities, ecology, and management regimes. The PLFA method has been shown to be sensitive to detecting shifts in microbial community composition. An alternative method, fatty acid methyl ester extraction and analysis (MIDI-FA) was developed for rapid extraction of total lipids, without separation of the phospholipid fraction, from pure cultures as a microbial identification technique. This method is rapid but is less suited for soil samples because it lacks an initial step separating soil particles and begins instead with a saponification reaction that likely produces artifacts from the background organic matter in the soil. This article describes a method that increases throughput while balancing effort and accuracy for extraction of lipids from the cell membranes of microorganisms for use in characterizing both total lipids and the relative abundance of indicator lipids to determine soil microbial community structure in studies with many samples. The method combines the accuracy achieved through PLFA profiling by extracting and concentrating soil lipids as a first step, and a reduction in effort by saponifying the organic material extracted and processing with the MIDI-FA method as a second step. PMID:28745639

Unravelling Soil Fungal Communities from Different Mediterranean Land-Use Backgrounds

PubMed Central

Nilsson, R. Henrik; Girlanda, Mariangela; Vizzini, Alfredo; Bonfante, Paola; Bianciotto, Valeria

2012-01-01

Background Fungi strongly influence ecosystem structure and functioning, playing a key role in many ecological services as decomposers, plant mutualists and pathogens. The Mediterranean area is a biodiversity hotspot that is increasingly threatened by intense land use. Therefore, to achieve a balance between conservation and human development, a better understanding of the impact of land use on the underlying fungal communities is needed. Methodology/Principal Findings We used parallel pyrosequencing of the nuclear ribosomal ITS regions to characterize the fungal communities in five soils subjected to different anthropogenic impact in a typical Mediterranean landscape: a natural cork-oak forest, a pasture, a managed meadow, and two vineyards. Marked differences in the distribution of taxon assemblages among the different sites and communities were found. Data analyses consistently indicated a sharp distinction of the fungal community of the cork oak forest soil from those described in the other soils. Each soil showed features of the fungal assemblages retrieved which can be easily related to the above-ground settings: ectomycorrhizal phylotypes were numerous in natural sites covered by trees, but were nearly completely missing from the anthropogenic and grass-covered sites; similarly, coprophilous fungi were common in grazed sites. Conclusions/Significance Data suggest that investigation on the below-ground fungal community may provide useful elements on the above-ground features such as vegetation coverage and agronomic procedures, allowing to assess the cost of anthropogenic land use to hidden diversity in soil. Datasets provided in this study may contribute to future searches for fungal bio-indicators as biodiversity markers of a specific site or a land-use degree. PMID:22536336

Enrichment and geochemical mobility of heavy metals in bottom sediment of the Hoedong reservoir, Korea and their source apportionment.

PubMed

Lee, Pyeong-Koo; Kang, Min-Ju; Yu, Soonyoung; Ko, Kyung-Seok; Ha, Kyoochul; Shin, Seong-Cheon; Park, Jung Han

2017-10-01

Physicochemical characteristics of bottom sediment in the Hoedong reservoir were studied to evaluate the effectiveness of the reservoir as traps for trace metals. Roadside soil, stream sediment and background soil were also studied for comparison. Sequential extractions were carried out, and lead isotopic compositions of each extraction were determined to apportion Pb sources. Besides, particle size distribution of roadside soil, and metal concentrations and Pb isotopes of each size group were determined to characterize metal contamination. In result, Zn and Cu were enriched in sediment through roadside soil. The data on metal partitioning implied that Zn posed potential hazards for water quality. Meanwhile, the noticeable reduction of the 206 Pb/ 207 Pb isotopic ratio in the acid-soluble fraction in the size group 200 μm - 2 mm of national roadside soil indicated that this size group was highly contaminated by automotive emission with precipitation of acid-soluble secondary minerals during evaporation. Based on the Pb isotopic ratios, the dry deposition of Asian dust (AD) and non-Asian dust (NAD) affected roadside soil, while the effects of AD and NAD on bottom sediment appeared to be low given the low metal concentrations in sediment. Metal concentrations and Pb isotopic compositions indicated that sediments were a mixture of background and roadside soil. Source apportionment calculations showed that the average proportion of traffic Pb in bottom and stream sediments was respectively 34 and 31% in non-residual fractions, and 26 and 28% in residual fraction. The residual fraction of sediments appeared to be as contaminated as the non-residual fractions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessment of ambient background concentrations of elements in soil using combined survey and open-source data.

PubMed

Mikkonen, Hannah G; Clarke, Bradley O; Dasika, Raghava; Wallis, Christian J; Reichman, Suzie M

2017-02-15

Understanding ambient background concentrations in soil, at a local scale, is an essential part of environmental risk assessment. Where high resolution geochemical soil surveys have not been undertaken, soil data from alternative sources, such as environmental site assessment reports, can be used to support an understanding of ambient background conditions. Concentrations of metals/metalloids (As, Mn, Ni, Pb and Zn) were extracted from open-source environmental site assessment reports, for soils derived from the Newer Volcanics basalt, of Melbourne, Victoria, Australia. A manual screening method was applied to remove samples that were indicated to be contaminated by point sources and hence not representative of ambient background conditions. The manual screening approach was validated by comparison to data from a targeted background soil survey. Statistical methods for exclusion of contaminated samples from background soil datasets were compared to the manual screening method. The statistical methods tested included the Median plus Two Median Absolute Deviations, the upper whisker of a normal and log transformed Tukey boxplot, the point of inflection on a cumulative frequency plot and the 95th percentile. We have demonstrated that where anomalous sample results cannot be screened using site information, the Median plus Two Median Absolute Deviations is a conservative method for derivation of ambient background upper concentration limits (i.e. expected maximums). The upper whisker of a boxplot and the point of inflection on a cumulative frequency plot, were also considered adequate methods for deriving ambient background upper concentration limits, where the percentage of contaminated samples is <25%. Median ambient background concentrations of metals/metalloids in the Newer Volcanic soils of Melbourne were comparable to ambient background concentrations in Europe and the United States, except for Ni, which was naturally enriched in the basalt-derived soils of Melbourne. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessment of environmentally persistent free radicals in soils and sediments from three Superfund sites.

PubMed

dela Cruz, Albert Leo N; Cook, Robert L; Dellinger, Barry; Lomnicki, Slawomir M; Donnelly, Kirby C; Kelley, Matthew A; Cosgriff, David

2014-01-01

We previously reported the presence of environmentally persistent free radicals (EPFRs) in pentachlorophenol (PCP) contaminated soils at a closed wood treatment facility site in Georgia. The reported EPFRs were pentachlorophenoxyl radicals formed on soils under ambient conditions via electron transfer from PCP to electron acceptors in the soil. In this study, we present results for soil and sediment samples from additional Superfund sites in Montana and Washington. Paramagnetic centers associated with different chemical environments were characterized by distinct g-factors and line widths (ΔHp-p). EPFR concentrations in contaminated samples were ~30×, ~12×, and ~2× higher than background samples at the Georgia, Montana, and Washington sites, respectively. EPR signals in the Montana contaminated soils were very similar to those previously observed for pentachlorophenol contaminated soils at the Georgia site, i.e., g = 2.00300 and ΔHp-p = 6.0 G, whereas signals in the Washington sediment samples were similar to those previously observed for other PAH contaminated soils, i.e., g = 2.00270 and ΔHp-p = 9.0 G. Total carbon content measurements exhibited direct correlation with EPFR concentration. The presence of radicals in sites contaminated a decade to a century ago suggests continuous formation of EPFRs from molecular contaminants in the soil and sediment.

Assessment of Environmentally Persistent Free Radicals in Soils and Sediments from Three Superfund Sites

PubMed Central

dela Cruz, Albert Leo N.; Cook, Robert L.; Dellinger, Barry; Lomnicki, Slawomir M.; Donnelly, Kirby C.; Kelley, Matthew A.; Cosgriff, David

2014-01-01

We previously reported the presence of environmentally persistent free radicals (EPFRs) in pentachlorophenol (PCP) contaminated soils at a closed wood treatment facility site in Georgia. The reported EPFRs were pentachlorophenoxyl radicals formed on soils under ambient conditions via electron transfer from PCP to electron acceptors in the soil. In this study, we present results for soil and sediment samples from additional Superfund sites in Montana and Washington. Paramagnetic centers associated with different chemical environments were characterized by distinct g-factors and line widths (ΔHp-p). EPFR concentrations in contaminated samples were ~30x, ~12x, and ~2x higher than background samples at the Georgia, Montana, and Washington sites, respectively. EPR signals in the Montana contaminated soils were very similar to those previously observed for pentachlorophenol contaminated soils at the Georgia site, i.e., g = 2.00300 and ΔHp-p = 6.0 G, whereas signals in the Washington sediment samples were similar to those previously observed for other PAH contaminated soils, i.e., g = 2.00270 and ΔHp-p = 9.0G. Total carbon content measurements exhibited direct correlation with EPFR concentration. The presence of radicals in sites contaminated a decade to a century ago suggests continuous formation of EPFRs from molecular contaminants in the soil and sediment. PMID:24244947

Cadmium background concentrations to establish reference quality values for soils of São Paulo State, Brazil.

PubMed

de Oliveira, Vinicius Henrique; de Abreu, Cleide Aparecida; Coelho, Ricardo Marques; Melo, Leônidas Carrijo Azevedo

2014-03-01

Proper assessment of soil cadmium (Cd) concentrations is essential to establish legislative limits. The present study aimed to assess background Cd concentrations in soils from the state of São Paulo, Brazil, and to correlate such concentrations with several soil attributes. The topsoil samples (n = 191) were assessed for total Cd contents and for other metals using the USEPA 3051A method. The background concentration was determined according to the third quartile (75th). Principal component analysis, Spearman correlation, and multiple regressions between Cd contents and other soil attributes (pH, cation exchange capacity (CEC), clay content, sum of bases, organic matter, and total Fe, Al, Zn, and Pb levels) were performed. The mean Cd concentration of all 191 samples was 0.4 mg kg(-1), and the background concentration was 0.5 mg kg(-1). After the samples were grouped by parent material (rock origin) and soil type, the background Cd content varied, i.e., soils from igneous, metamorphic, and sedimentary rocks harbored 1.5, 0.4, and 0.2 mg kg(-1) of Cd, respectively. The background Cd content in Oxisols (0.8 mg kg(-1)) was higher than in Ultisols (0.3 mg kg(-1)). Multiple regression demonstrated that Fe was primarily attributed to the natural Cd contents in the soils (R (2) = 0.79). Instead of a single Cd background concentration value representing all São Paulo soils, we propose that the concentrations should be specific for at least Oxisols and Ultisols, which are the primary soil types.

Proposed chemical mechanismsManagement practices impacts soil nutrients and bacterial populations in backgrounding beef feedlot

USDA-ARS?s Scientific Manuscript database

Intensive beef backgrounding often accumulate manure born soil nutrients, microbes, and pharmaceuticals at different site locations. Unless properly managed, such waste materials can pollute surrounding soil and water sources. Soil sampling from these sites helps determining waste material levels bu...

Changes in the biological activity of chestnut soils upon the long-term application of fertilizers in a rotation with oil-bearing crops

NASA Astrophysics Data System (ADS)

Eleshev, R. E.; Bakenova, Z. B.

2012-11-01

Experimental studies showed that irrigated chestnut soils on the piedmont of the Zailiiskiy Alatau Range are characterized by the moderate activity of the hydrolytic and redox enzymes. The use of these soils in the crop rotation system increases the hydrolytic activity of the enzymes (invertase, urease, and ATP synthase) by 30% in comparison with the monoculture; at the same time, it does not have a significant impact on the changes in the biological activity of the redox enzymes (catalase and dehydrogenase). The hydrolytic activity of the soils is activated to a greater extent in the crop rotation and in the monoculture against the background application of organic fertilizers. In this case, the recommended rates of mineral fertilizers do not inhibit the activity of the hydrolytic and redox enzymes. An increase in the hydrolytic activity of the enzymes directly affects the yield of oilseed flax. Therefore, indices of the hydrolytic activity of soils can be used as a test for the diagnostics of the efficiency of fertilizers both in crop rotation and monoculture systems.

Major and trace element geochemistry and background concentrations for soils in Connecticut

USGS Publications Warehouse

Brown, Craig; Thomas, Margaret A.

2014-01-01

Soil samples were collected throughout Connecticut (CT) to determine the relationship of soil chemistry with the underlying geology and to better understand background concentrations of major and trace elements in soils. Soil samples were collected (1) from the upper 5 cm of surficial soil at 100 sites, (2) from the A horizon at 86 of these sites, and (3) from the deeper horizon, typically the C horizon, at 79 of these sites. The <2-millimeter fraction of each sample was analyzed for 44 elements by methods that yield the total or near-total elemental content. Sample sites were characterized by glacial setting, underlying bedrock geology, and soil type. These spatial data were used with element concentrations in the C-horizon to relate geologic factors to soil chemistry. Concentrations of elements in C-horizon soils varied with grain size in surficial glacial materials and with underlying rock types, as determined using nonparametric statistical procedures. Concentrations of most elements in C-horizon soils showed a positive correlation with silt and (or) clay content and were higher in surficial materials mapped as till, thick till, and (or) fines. Element concentrations in C-horizon soils showed significant differences among the underlying geologic provinces and were highest overlying the Grenville Belt and (or) the Grenville Shelf Sequence Provinces in western CT. These rocks consist mainly of carbonates and the relatively high element concentrations in overlying soils likely result from less influence of dilution by quartz compared to other provinces. Element concentrations in C-horizon soils in CT were compared with those in samples from other New England states overlying similar lithologic bedrock types. The upper range of As concentrations in C-horizon soils overlying the New Hampshire-Maine (NH-ME) Sequence in CT was 15 mg/kg, lower than the upper range of 24 mg/kg in C-horizon soils overlying the same sequence in ME. In CT, U concentration means were significantly higher in C-horizon soils overlying Avalonian granites, and U concentrations ranged as high as 14 mg/kg, compared to those in C-horizon soil samples collected from other New England states, which ranged as high as 6.1 mg/kg in a sample in NH overlying the NH-ME Sequence. Element concentrations in C-horizon soils in CT were compared with those in samples collected from shallower depths. Concentrations of most major elements were highest in C-horizon soil samples, including Al, Ca, Fe, K, Na, and Ti, but element concentrations showed a relatively similar pattern in A-horizon and surficial soil samples among the underlying geologic provinces. Trace element concentrations, including Ba, W, Ga, Ni, Cs, Rb, Sr, Th, Sc, and U, also were higher in C-horizon soil samples than in overlying soil samples. Concentrations of Mg, and several trace elements, including Mn, P, As, Nb, Sn, Be, Bi, Hg, Se, Sb, La, Co, Cr, Pb, V, Y, Cu, Pb, and Zn were highest in some A-horizon or surficial soils, and indicate possible contributions from anthropogenic sources. Because element concentrations in soils above the C horizon are more likely to be affected by anthropogenic factors, concentration ranges in C-horizon soils and their spatially varying geologic associations should be considered when estimating background concentrations of elements in CT soils.

Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district.

PubMed

Witt, Emitt C; Pribil, Michael J; Hogan, John P; Wronkiewicz, David J

2016-09-01

The isotopic composition of lead (Pb) in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end-member model using (207)Pb/(206)Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the (207)Pb/(206)Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb-impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background conditions. Aqua regia total concentrations and (207)Pb/(206)Pb of mining area dust suggest that 35.4-84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1-52.7% is associated with the smelter mixture, and 0-21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil. Published by Elsevier Ltd.

Isotopically constrained lead sources in fugitive dust from unsurfaced roads in the southeast Missouri mining district

USGS Publications Warehouse

Witt, Emitt C.; Pribil, Michael; Hogan, John P; Wronkiewicz, David

2016-01-01

The isotopic composition of lead (Pb) in fugitive dust suspended by a vehicle from 13 unsurfaced roads in Missouri was measured to identify the source of Pb within an established long-term mining area. A three end-member model using 207Pb/206Pb and concentration as tracers resulted in fugitive dust samples plotting in the mixing field of well characterized heterogeneous end members. End members selected for this investigation include the 207Pb/206Pb for 1) a Pb-mixture representing mine tailings, 2) aerosol Pb-impacted soils within close proximity to the Buick secondary recycling smelter, and 3) an average of soils, rock cores and drill cuttings representing the background conditions. Aqua regia total concentrations and 207Pb/206Pb of mining area dust suggest that 35.4–84.3% of the source Pb in dust is associated with the mine tailings mixture, 9.1–52.7% is associated with the smelter mixture, and 0–21.6% is associated with background materials. Isotope ratios varied minimally within the operational phases of sequential extraction suggesting that mixing of all three Pb mixtures occurs throughout. Labile forms of Pb were attributed to all three end members. The extractable carbonate phase had as much as 96.6% of the total concentration associated with mine tailings, 51.8% associated with smelter deposition, and 34.2% with background. The next most labile geochemical phase (Fe + Mn Oxides) showed similar results with as much as 85.3% associated with mine tailings, 56.8% associated with smelter deposition, and 4.2% associated with the background soil.

Selective, high-energy beta scintillation sensor for real-time, in situ characterization of uranium-238 and strontium-90

NASA Astrophysics Data System (ADS)

Schilk, A. J.; Abel, K. H.; Brown, D. P.; Thompson, R. C.; Knopf, M. A.; Hubbard, C. W.

1994-04-01

A novel scintillating-fiber sensor for detecting high-energy beta particles has been designed and built at the Pacific Northwest Laboratory to characterize U-238 and Sr-90 in surface soils. High-energy betas generate unique signals as they pass through multiple layers of scintillating fibers that make up the active region of the detector. Lower-energy beta particles, gamma rays, and cosmic-ray-generated particles comprise the majority of the background interferences. The resulting signals produced by these latter phenomena are effectively discriminated against due to the combination of the sensor's multilayer configuration and its interlayer coincidence/anticoincidence circuitry.

Testing the Li-Strahler four-component canopy reflectance model in the HAPEX-Sahel shrub savanna sites using ground reflectance data

NASA Technical Reports Server (NTRS)

Franklin, J.; Duncan, J.

1992-01-01

The rate at which a light field decays in water is characterized by the diffuse attenuation coefficient k. The Li-Strahler discrete-object canopy reflectance model was tested in two sites, a shrub grass savanna and a degraded shrub savanna on bare soil, in the proposed HAPEX (Hydrologic Atmospheric Pilot Experiment) II/Sahel study area in Niger, West Africa. Average site reflectance was predicted for each site from the reflectances and cover proportions of four components: shrub canopy, background (soil or grass and soil), shaded canopy, and shaded background. Component reflectances were sampled in the SPOT wavebands using a hand-held radiometer. Predicted reflectance was compared to average site reflectance measured using the same radiometer mounted on a backpack with measurements recorded every 5 m along two 1-km transects, also in the SPOT (Systeme Probatoire d'Observation de la Terre) bands. Measurements and predictions were made for each of the three days during the summer growing season, approximately two weeks apart. Red, near infrared reflectance, and the NDVI (normalized difference vegetation index) were all predicted with a high degree of accuracy for the shrub/grass site and with reasonable accuracy for the degraded shrub site.

The structure of red-infrared scattergrams of semivegetated landscapes

NASA Technical Reports Server (NTRS)

Jasinski, Michael F.; Eagleson, Peter S.

1988-01-01

A physically based linear stochastic geometric canopy soil reflectance model is presented for characterizing spatial variability of semivegetated landscapes at subpixel and regional scales. Landscapes are conceptualized as stochastic geometric surfaces, incorporating not only the variability in geometric elements, but also the variability in vegetation and soil background reflectance which can be important in some scenes. The model is used to investigate several possible mechanisms which contribute to the often observed characteristic triangular shape of red-infrared scattergrams of semivegetated landscapes. Scattergrams of simulated and semivegetated scenes are analyzed with respect to the scales of the satellite pixel and subpixel components. Analysis of actual aerial radiometric data of a pecan orchard is presented in comparison with ground observations as preliminary confirmation of the theoretical results.

The structure of red-infrared scattergrams of semivegetated landscapes

NASA Technical Reports Server (NTRS)

Jasinski, Michael F.; Eagleson, Peter S.

1989-01-01

A physically based linear stochastic geometric canopy soil reflectance model is presented for characterizing spatial variability of semivegetated landscapes at subpixel and regional scales. Landscapes are conceptualized as stochastic geometric surfaces, incorporating not only the variability in geometric elements, but also the variability in vegetation and soil background reflectance which can be important in some scenes. The model is used to investigate several possible mechanisms which contribute to the often observed characteristic triangular shape of red-infrared scattergrams of semivegetated landscapes. Scattergrams of simulated semivegetated scenes are analyzed with respect to the scales of the satellite pixel and subpixel components. Analysis of actual aerial radiometric data of a pecan orchard is presented in comparison with ground observations as preliminary confirmation of the theoretical results.

Radiative transfer in shrub savanna sites in Niger: Preliminary results from HAPEX-Sahel. Part 3: Optical dynamics and vegetation index sensitivity to biomass and plant cover

NASA Technical Reports Server (NTRS)

vanLeeuwen, W. J. D.; Huete, A. R.; Duncan, J.; Franklin, J.

1994-01-01

A shrub savannah landscape in Niger was optically characterized utilizing blue, green, red and near-infrared wavelengths. Selected vegetation indices were evaluated for their performance and sensitivity to describe the complex Sahelian soil/vegetation canopies. Bidirectional reflectance factors (BRF) of plants and soils were measured at several view angles, and used as input to various vegetation indices. Both soil and vegetation targets had strong anisotropic reflectance properties, rendering all vegetation index (6) responses to be a direct function of sun and view geometry. Soil background influences were shown to alter the response of most vegetation indices. N-space greenness had the smallest dynamic range in VI response, but the n-space brightness index provided additional useful information. The global environmental monitoring index (GEMI) showed a large 6 dynamic range for bare soils, which was undesirable for a vegetation index. The view angle response of the normalized difference vegetation index (NDVI), atmosphere resistant vegetation index (ARVI) and soil atmosphere resistant vegetation index (SARVI) were asymmetric about nadir for multiple view angles, and were, except for the SARVI, altered seriously by soil moisture and/or soil brightness effects. The soil adjusted vegetation index (SAVI) was least affected by surface soil moisture and was symmetric about nadir for grass vegetation covers. Overall the SAVI, SARVI and the n-space vegetation index performed best under all adverse conditions and were recommended to monitor vegetation growth in the sparsely vegetated Sahelian zone.

Localized application of soil organic matter shifts distribution of cluster roots of white lupin in the soil profile due to localized release of phosphorus

PubMed Central

Li, Hai-Gang; Shen, Jian-Bo; Zhang, Fu-Suo; Lambers, Hans

2010-01-01

Background and Aims Phosphorus (P) is a major factor controlling cluster-root formation. Cluster-root proliferation tends to concentrate in organic matter (OM)-rich surface-soil layers, but the nature of this response of cluster-root formation to OM is not clear. Cluster-root proliferation in response to localized application of OM was characterized in Lupinus albus (white lupin) grown in stratified soil columns to test if the stimulating effect of OM on cluster-root formation was due to (a) P release from breakdown of OM; (b) a decrease in soil density; or (c) effects of micro-organisms other than releasing P from OM. Methods Lupin plants were grown in three-layer stratified soil columns where P was applied at 0 or 330 mg P kg−1 to create a P-deficient or P-sufficient background, and OM, phytate mixed with OM, or perlite was applied to the top or middle layers with or without sterilization. Key Results Non-sterile OM stimulated cluster-root proliferation and root length, and this effect became greater when phytate was supplied in the presence of OM. Both sterile OM and perlite significantly decreased cluster-root formation in the localized layers. The OM position did not change the proportion of total cluster roots to total roots in dry biomass among no-P treatments, but more cluster roots were concentrated in the OM layers with a decreased proportion in other places. Conclusions Localized application of non-sterile OM or phytate plus OM stimulated cluster-root proliferation of L. albus in the localized layers. This effect is predominantly accounted for by P release from breakdown of OM or phytate, but not due to a change in soil density associated with OM. No evidence was found for effects of micro-organisms in OM other than those responsible for P release. PMID:20150198

Soil spectral characterization

NASA Technical Reports Server (NTRS)

Stoner, E. R.; Baumgardner, M. F.

1981-01-01

The spectral characterization of soils is discussed with particular reference to the bidirectional reflectance factor as a quantitative measure of soil spectral properties, the role of soil color, soil parameters affecting soil reflectance, and field characteristics of soil reflectance. Comparisons between laboratory-measured soil spectra and Landsat MSS data have shown good agreement, especially in discriminating relative drainage conditions and organic matter levels in unvegetated soils. The capacity to measure both visible and infrared soil reflectance provides information on other soil characteristics and makes it possible to predict soil response to different management conditions. Field and laboratory soil spectral characterization helps define the extent to which intrinsic spectral information is available from soils as a consequence of their composition and field characteristics.

Isolation and Characterization of Alfalfa-Nodulating Rhizobia Present in Acidic Soils of Central Argentina and Uruguay

PubMed Central

del Papa, María F.; Balagué, Laura J.; Sowinski, Susana Castro; Wegener, Caren; Segundo, Eduardo; Abarca, Francisco Martínez; Toro, Nicolás; Niehaus, Karsten; Pühler, Alfred; Aguilar, O. Mario; Martínez-Drets, Gloria; Lagares, Antonio

1999-01-01

We describe the isolation and characterization of alfalfa-nodulating rhizobia from acid soils of different locations in Central Argentina and Uruguay. A collection of 465 isolates was assembled, and the rhizobia were characterized for acid tolerance. Growth tests revealed the existence of 15 acid-tolerant (AT) isolates which were able to grow at pH 5.0 and formed nodules in alfalfa with a low rate of nitrogen fixation. Analysis of those isolates, including partial sequencing of the genes encoding 16S rRNA and genomic PCR-fingerprinting with MBOREP1 and BOXC1 primers, demonstrated that the new isolates share a genetic background closely related to that of the previously reported Rhizobium sp. Or191 recovered from an acid soil in Oregon (B. D. Eardly, J. P. Young, and R. K. Selander, Appl. Environ. Microbiol. 58:1809–1815, 1992). Growth curves, melanin production, temperature tolerance, and megaplasmid profiles of the AT isolates were all coincident with these characteristics in strain Or191. In addition to the ability of all of these strains to nodulate alfalfa (Medicago sativa) inefficiently, the AT isolates also nodulated the common bean and Leucaena leucocephala, showing an extended host range for nodulation of legumes. In alfalfa, the time course of nodule formation by the AT isolate LPU 83 showed a continued nodulation restricted to the emerging secondary roots, which was probably related to the low rate of nitrogen fixation by the largely ineffective nodules. Results demonstrate the complexity of the rhizobial populations present in the acidic soils represented by a main group of N2-fixing rhizobia and a second group of ineffective and less-predominant isolates related to the AT strain Or191. PMID:10103231

Redistribution of magnetic iron oxide along soil profile after eight years managing a commercial olive orchard in a Vertisol

NASA Astrophysics Data System (ADS)

Guzmán, Gema; Gómez, José Alfonso

2017-04-01

Magnetic iron oxide has been used as a tracer to monitor top soil movement and to identify source of sediments at the short-term scale, after high intensity rainfall events (Guzmán et al., 2010; Obereder et al., 2016) and periods up to two years (Guzmán et al., 2013). As it can be strongly bound to soil particles, its use allows the tacking of tagged soil all over the years until all this soil is lost or it is totally diluted with blank soil making the signal undetectable. Olive orchards planted on Vertisols are subject not only to tillage operations modifying soil profile but also to expansion-compression cycles and cracks appearance due to soil moisture changes. The aim of communication is to assess the soil movement at the mid-term scale, taking advantage of a tracer trial already performed by Guzmán et al. (2013) and a new sampling after 8 years of soil disturbance. In October 2008 two plots of 330 m2 were delimited and in which the top 5 cm of the inter tree rows were tagged with magnetite. Seventy locations at both plots were sampled so as to measure magnetic susceptibility twice (just after the tagging and March 2010), at three depth intervals (0-1, 1-8 and 8-12 cm) and distinguishing two zones: tree and inter tree rows. A third sampling was carried out at 0-2, 2-10 and 10-20 cm in August 2016 at the same locations and zones. Furthermore, in twenty of the sampling points additional samples from 20-30, 30-40, 40-50 and 50-60 cm were taken to check if tagged soil went deeper into the soil profile. Background values of susceptibility and bulk density at each depth, were characterized as well at the three sampling campaigns. Rainfall, soil management during these years and the inherent characteristics of a Vertisol have enhanced the movement of top soil not only superficially but also within the soil profile. First results comparing the evolution of magnetite distribution along soil profile indicate that while in 2008 and 2010 background values were measured at 12 cm, in 2016, in both zones (tree and inter tree rows) magnetite decreases slightly from the 10-20 cm interval but still finding tagged soil at a depth of 60 cm where background values were nearly reached. The implications of these results on the use of erosion magnetic tracers in long-term erosion experiments and soil vertical fluxes in Vertic soils will be discussed. References: Guzmán G., Vanderlinden K., Giráldez J.V., Gómez J. A. 2013. Assessment of spatial variability in water erosion rates in an olive orchard at plot scale using a magnetic iron oxide tracer. Soil Science Society of America Journal, 77(2), 350-361. Guzmán G., Barrón V., Gómez J.A. 2010. Evaluation of magnetic iron oxides as sediment tracers in water erosion experiments. Catena, 82(2), 126-133. Obereder E., Klik A., Wakolbinger S., Guzmán G., Strohmeier S., Demelash N., Gómez, J.A. 2016. Investigation of the impact of stone bunds on erosion and deposition processes combining conventional and tracer methodology in the Gumara Maksegnit watershed, Northern highlands of Ethiopia. In EGU General Assembly Conference Abstracts (Vol. 18, p. 2455).

[Environmental geochemical baseline of heavy metals in soils of the Ili river basin and pollution evaluation].

PubMed

Zhao, Xin-Ru; Nasier, Telajin; Cheng, Yong-Yi; Zhan, Jiang-Yu; Yang, Jian-Hong

2014-06-01

Environmental geochemical baseline models of Cu, Zn, Pb, As, Hg were established by standardized method in the ehernozem, chestnut soil, sierozem and saline soil from the Ili river valley region. The theoretical baseline values were calculated. Baseline factor pollution index evaluation method, environmental background value evaluation method and heavy metal cleanliness evaluation method were used to compare soil pollution degrees. The baseline factor pollution index evaluation showed that As pollution was the most prominent among the four typical types of soils within the river basin, with 7.14%, 9.76%, 7.50% of sampling points in chernozem, chestnut soil and sierozem reached the heavy pollution, respectively. 7.32% of sampling points of chestnut soil reached the permitted heavy metal Pb pollution index in the chestnut soil. The variation extent of As and Pb was the largest, indicating large human disturbance. Environmental background value evaluation showed that As was the main pollution element, followed by Cu, Zn and Pb. Heavy metal cleanliness evaluation showed that Cu, Zn and Pb were better than cleanliness level 2 and Hg was the of cleanliness level 1 in all four types of soils. As showed moderate pollution in sierozem, and it was of cleanliness level 2 or better in chernozem, chestnut soil and saline-alkali soil. Comparing the three evaluation systems, the baseline factor pollution index evaluation more comprehensively reflected the geochemical migration characteristics of elements and the soil formation processes, and the pollution assessment could be specific to the sampling points. The environmental background value evaluation neglected the natural migration of heavy metals and the deposition process in the soil since it was established on the regional background values. The main purpose of the heavy metal cleanliness evaluation was to evaluate the safety degree of soil environment.

Brine Spills Associated with Unconventional Oil Development in North Dakota.

PubMed

Lauer, Nancy E; Harkness, Jennifer S; Vengosh, Avner

2016-05-17

The rapid rise of unconventional oil production during the past decade in the Bakken region of North Dakota raises concerns related to water contamination associated with the accidental release of oil and gas wastewater to the environment. Here, we characterize the major and trace element chemistry and isotopic ratios ((87)Sr/(86)Sr, δ(18)O, δ(2)H) of surface waters (n = 29) in areas impacted by oil and gas wastewater spills in the Bakken region of North Dakota. We establish geochemical and isotopic tracers that can identify Bakken brine spills in the environment. In addition to elevated concentrations of dissolved salts (Na, Cl, Br), spill waters also consisted of elevated concentrations of other contaminants (Se, V, Pb, NH4) compared to background waters, and soil and sediment in spill sites had elevated total radium activities ((228)Ra + (226)Ra) relative to background, indicating accumulation of Ra in impacted soil and sediment. We observed that inorganic contamination associated with brine spills in North Dakota is remarkably persistent, with elevated levels of contaminants observed in spills sites up to 4 years following the spill events.

Mississippi River Headwaters Lakes in Minnesota. Feasibility Study. Appendices.

DTIC Science & Technology

1982-09-01

CONTENTS ITEM PAGE INTRODUCTION A-1 PROBLEM 1 - HEADWATERS LAKES OPERATING PLANS A-1 BACKGROUND A-1 GEOLOGY AND SOILS A-3 STREAM CHARACTERISTICS A- 7...HEADWATERS LAKES A-134 BACKGROUND A- 134 GEOLOGY AND SOILS A-135 HYDROLOGY AND HYDRAULIC STUDIES A- 135 COST ESTIMATE A- 142 RECOMMENDED ACT ION A...143 PLATE SUMMARY A-144 PROBLEM 3 - EROSION PROBLEMS DOWNSTREAM OF POKEGAMA DAM A-158 BACKGROUND A- 158 GEOLOGY AND SOILS A- 158 HYDROLOGY AND HYDRAULIC

Chemical and radiological characterization of fly and bottom ash landfill of the former sulfate pulp factory Plaški and its surroundings.

PubMed

Oreščanin, Višnja; Kollar, Robert; Buben, Kresimir; Mikelic, Ivanka Lovrencic; Kollar, Karlo; Kollar, Melkior; Medunic, Gordana

2012-01-01

The subject of this study was chemical and radiological characterization of the fly and bottom ash, by-product of the combustion of coal used as an energy source in the former sulfate pulp factory in Plaški. The research involves determination of the concentration of macro, micro and trace elements and activities of the radionuclides in: (i) ash from different positions of the landfill; (ii) soil samples in the zone of the influence of the landfill; (iii) control soil samples and (iv) sediment sample from the river Dretulja. Besides, in situ measurement of an effective dose rate above ash/soil was also determined. In relation with the control soil the average increase of the concentrations of the elements Ca, Cd, Hg, Ni, Se, Sr, Th and U in the samples taken from the fly and bottom ash landfill as well as soil samples within the radius of 300 m from the landfill was 38.3, 6.7, 9.9, 8.5, 9.4, 7.2, 3.6 and 5.7 times, respectively. In these samples, the concentrations of the above mentioned elements were in the following ranges: calcium from 7.94 to 19.7 %; cadmium from 0.33 to 1.66 mg/kg; mercury from 0.18 to 0.49 mg/kg; nickel from 260 to 1500 mg/kg; selenium from 2.7 to 21 mg/kg; strontium from 176 to 542 mg/kg; thorium from 8 to 55 mg/kg and uranium from 5.6 to 19.7 mg/kg. Compared to the world's average soil concentration, uranium and thorium values increased 3.7 and 1.7 times, respectively. The mean value of the total effective dose rate measured in the air at the height of 1 m for all samples of ash and soil under the influence of the landfill was 1.60 mSv/yr. Compared to the Croatian average (0.7015 mSv/yr), the determined mean value for the Plaški landfill is two times higher. However, compared to the local background (0.14 mSv/yr), the mean value of the total effective dose rate measured above the Plaški landfill is 11.4 times higher. In the samples of ash and contaminated soil regardless of the sampling location the activity concentrations of the radionuclides in Bq/kg vary in the following ranges: (226)Ra from 82.10 to 314.90 (mean value 145.99), (232)Th from 32.50 to 223.60 (mean value 76.76) and (238)U from 69.10 to 243.20 (mean value 134.38). Compared to the mean values found in the background soil (226)Ra and (238)U mean activity concentrations increased from 1.6 to 6.4 times and (232)Th from 1.4 to 4.3 times. In order to reduce total effective dose rate to the local "background" values and to prevent redistribution of the radionuclides and heavy metals from the deposited material into the environment fly and bottom ash landfill must be sealed with 10 cm thick layer of the material with low permeability.

Arsenic and metals in soils in the vicinity of the Imperial Oil Company Superfund Site, Marlboro Township, Monmouth County, New Jersey. Water-resources investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barringer, J.L.; Szabo, Z.; Barringer, T.H.

1998-09-01

Concentrations of arsenic exceed the New Jersey State Cleanup Criterion of 20 parts per million in sandy and clay-rich soils of two residential areas in the vicinity of the Imperial Oil Company Superfund site in Marlboro Township, Monmouth County, New Jersey. In order to determine the source of the arsenic and metals in soils in the two residential areas, soil samples were collected from (1) long-term forested areas, to determine background geologic and regional atmospheric inputs of arsenic and metals; (2) former and current orchards, to assess the range of concentrations of arsenic and metals that could be contributed bymore » past use of pesticides; (3) the Imperial Oil Company Superfund site, to characterize the chemical composition of contamination from activities at the site; (4) a wooded area adjacent to the Superfund site, to determine whether arsenic and metals from the Superfund site were evident; and (5) the two residential areas, to compare soil chemistry in these areas with the chemistry of soils from forests, orchards, and the Superfund site. The soil samples were divided by soil horizon and were analyzed for 23 metals and metalloids, total organic carbon, and total sulfur. Additionally, air-flow models were used to determine whether roasting of arsenic at the Imperial Oil Company Superfund site was a possible source of arsenic in the soils.« less

Soil dioxins levels at agriculture sites and natural preserve areas of Taiwan.

PubMed

Jou, Jin-juh; Lin, Kae-Long; Chung, Jen-Chir; Liaw, Shu-Liang

2007-08-17

In this study, agriculture soil in Taiwan has been sampled and analyzed to determine the background level of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DF) in the agricultural and nature preserve areas. Another objective is to investigate relationship between soil characteristics and air deposition in Taiwan. The results indicate that in nature preserve areas the topsoil shows an extraordinary profile of PCDD/DF compared to that in the air deposition. The PCDD/DF levels of the low-contaminated agricultural soils are compatible with those of the nature preserves soils. However, in the highly-contaminated agricultural soils, there is an abrupt jump in their concentrations, 10-100 times higher. The overall I-TEQ values of the background topsoils range from 0.101 to 15.2 ng I-TEQ/kg. Near industrial/urban areas in Taiwan the PCDD/DF are slightly higher compared to those in the low concentration group. Typically, the PCDD/DF background values found in this survey fall in the 90% confidence interval and can thus, be deemed the background levels in Taiwan. Ninety-five percent of these data are below the European and American soil standard of 10 ng I-TEQ/kg d.w. The PCDD/DF profile with one neighborhood soil sample was shown no significant difference.

Distinguishing vegetation from soil background information. [by gray mapping of Landsat MSS data

NASA Technical Reports Server (NTRS)

Richardson, A. J.; Wiegand, C. L.

1977-01-01

In aircraft and satellite multispectral scanner data, soil background signals are superimposed on or intermingled with information about vegetation. A procedure which accounts for soil background would, therefore, make a considerable contribution to an operational use of Landsat and other spectral data for monitoring the productivity of range, forest, and crop lands. A description is presented of an investigation which was conducted to obtain information for the development of such a procedure. The investigation included a study of the soil reflectance that supplies the background signal of vegetated surfaces. Landsat data as recorded on computer compatible tapes were used in the study. The results of the investigation are discussed, taking into account a study reported by Kauth and Thomas (1976). Attention is given to the determination of Kauth's plane of soils, sun angle effects, vegetation index modeling, and the evaluation of vegetation indexes. Graphs are presented which show the results obtained with a gray mapping technique. The technique makes it possible to display plant, soil, water, and cloud conditions for any Landsat overpass.

ForCent model development and testing using the Enriched Background Isotope Study experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parton, W.J.; Hanson, P. J.; Swanston, C.

The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool {sup 14}C signature ({Delta} {sup 14}C) data from the Enriched Background Isotope Study {sup 14}C experiment (1999-2006) shows that the model correctly simulatesmore » the temporal dynamics of the {sup 14}C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass {Delta} {sup 14}C data, and with soil respiration {Delta} {sup 14}C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study {sup 14}C experimental treatments on soil respiration {Delta} {sup 14}C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.« less

ForCent Model Development and Testing using the Enriched Background Isotope Study (EBIS) Experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parton, William; Hanson, Paul J; Swanston, Chris

The ForCent forest ecosystem model was developed by making major revisions to the DayCent model including: (1) adding a humus organic pool, (2) incorporating a detailed root growth model, and (3) including plant phenological growth patterns. Observed plant production and soil respiration data from 1993 to 2000 were used to demonstrate that the ForCent model could accurately simulate ecosystem carbon dynamics for the Oak Ridge National Laboratory deciduous forest. A comparison of ForCent versus observed soil pool 14C signature (? 14C) data from the Enriched Background Isotope Study 14C experiment (1999-2006) shows that the model correctly simulates the temporal dynamicsmore » of the 14C label as it moved from the surface litter and roots into the mineral soil organic matter pools. ForCent model validation was performed by comparing the observed Enriched Background Isotope Study experimental data with simulated live and dead root biomass ? 14C data, and with soil respiration ? 14C (mineral soil, humus layer, leaf litter layer, and total soil respiration) data. Results show that the model correctly simulates the impact of the Enriched Background Isotope Study 14C experimental treatments on soil respiration ? 14C values for the different soil organic matter pools. Model results suggest that a two-pool root growth model correctly represents root carbon dynamics and inputs to the soil. The model fitting process and sensitivity analysis exposed uncertainty in our estimates of the fraction of mineral soil in the slow and passive pools, dissolved organic carbon flux out of the litter layer into the mineral soil, and mixing of the humus layer into the mineral soil layer.« less

National surveillance of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins/furans in soil in Taiwan.

PubMed

Hsu, Yi-Chyun; Que, Danielle E; Gou, Yan-You; Tsou, Tsui-Chun; Liu, Chung-Kun; Wang, Yen-Ling; Hou, Wen-Che; Lin, Yi-Hsien; Liu, Wen-Yao; Chao, How-Ran; Lee, Wen-Jhy

2018-07-01

In this study, the polychlorinated dibenzo-p-dioxin/furan (PCDD/F) levels in 381 soil samples coming from different background areas (n = 238) and contaminated areas (n = 143) in Taiwan were investigated from 2011 to 2015 using high resolution gas chromatograph/high resolution mass spectrometry (HRGC/HRMS). The contaminated areas showed higher PCDD/F contamination as compared to the background areas (1230 vs 749 pg/g dry weight (dw)); 14.0 vs 6.25 pg WHO 2005 -TEQ/g dw). The lowest levels were recorded in the outlying islands (1.28 pg WHO 2005 -TEQ/g dw). PCDD/F congener distribution profiles in the background and contaminated areas as well as on the islands varied. OCDD was the dominant congener in almost all locations, including the northern background (87.7%) and central contaminated (74.2%) areas. Other dominant species included OCDF and 1,2,3,4,6,7,8-HpCDD. Levels of PCDD/F-TEQs in Taiwanese soils, including the background areas, were higher than in some developing countries and regions with global background levels due to high industrialization except for the contaminated areas. Geographic differences in dioxin-contaminated soils were also shown in this study. Higher soil dioxin-TEQs were observed in locations with high populations and population densities. Despite the limitations, the economic status of Taiwan represented by the annual averaged family income (AAFI) was positively correlated to soil dioxin-TEQs. Copyright © 2018. Published by Elsevier Ltd.

Using radiocarbon to investigate soil respiration impacts on atmospheric CO2

NASA Astrophysics Data System (ADS)

Phillips, C. L.; LaFranchi, B. W.; McFarlane, K. J.; Desai, A. R.

2013-12-01

While soil respiration is believed to represent the largest single source of CO2 emissions on a global scale, there are few tools available to measure soil emissions at large spatial scales. We investigated whether radiocarbon (14C) abundance in CO2 could be used to detect and characterize soil emissions in the atmosphere, taking advantage of the fact that 14C abundance in soil carbon is elevated compared to the background atmosphere, a result of thermonuclear weapons testing during the mid-20th Century (i.e. bomb-C). Working in a temperate hardwood forest in Northern Wisconsin during 2011-12, we made semi-high-frequency measurements of CO2 at nested spatial scales from the soil subsurface to 150 m above ground level. These measurements were used to investigate seasonal patterns in respired C sources, and to evaluate whether variability in soil-respired Δ14C could also be detected in atmospheric measurements. In our ground-level measurements we found large seasonal variation in soil-respired 14CO2 that correlated with soil moisture, which was likely related to root activity. Atmospheric measurements of 14CO2 in the forest canopy (2 to 30m) were used to construct Keeling plots, and these provided larger spatial-scale estimates of respired 14CO2 that largely agreed with the soil-level measurements. In collaboration with the NOAA we also examined temporal patterns of 14CO2 at the Park Falls tall-tower (150m), and found elevated 14CO2 levels during summer months that likely resulted from increased respiration from heterotrophic sources. These results demonstrate that a fingerprint from soil-respired CO2 can be detected in the seasonal patterns of atmospheric 14CO2, even at a regionally-integrating spatial scale far from the soil surface.

Assessment of contamination from arsenical pesticide use on orchards in the great valley region, Virginia and West Virginia, USA

USGS Publications Warehouse

Robinson, G.R.; Larkin, S.P.; Boughton, C.J.; Reed, B.W.; Sibrell, P.L.

2007-01-01

Lead arsenate pesticides were widely used in apple orchards from 1925 to 1955. Soils from historic orchards in four counties in Virginia and West Virginia contained elevated concentrations of As and Pb, consistent with an arsenical pesticide source. Arsenic concentrations in approximately 50% of the orchard site soils and approximately 1% of reference site soils exceed the USEPA Preliminary Remediation Goal (PRG) screening guideline of 22 mg kg-1 for As in residential soi, defined on the basis of combined chronic exposure risk. Approximately 5% of orchard site soils exceed the USEPA PRG for Pb of 400 mg kg-1 in residential soil; no reference site soils sampled exceed this value. A variety of statistical methods were used to characterize the occurrence, distribution, and dispersion of arsenical pesticide residues in soils, stream sediments, and ground waters relative to landscape features and likely background conditions. Concentrations of Zn, Pb, and Cu were most strongly associated with high developed land density and population density, whereas elevated concentrations of As were weakly correlated with high orchard density, consistent with a pesticide residue source. Arsenic concentrations in ground water wells in the region are generally <0.005 mg L-1. There was no spatial association between As concentrations in ground water and proximity to orchards. Arsenic had limited mobility into ground water from surface soils contaminated with arsenical pesticide residues at concentrations typically found in orchards. ?? ASA, CSSA, SSSA.

Assessment of metal and PAH profiles in SUDS soil based on an improved experimental procedure.

PubMed

Tedoldi, Damien; Chebbo, Ghassan; Pierlot, Daniel; Kovacs, Yves; Gromaire, Marie-Christine

2017-11-01

The increasing use of infiltration-based systems for stormwater management questions the soil's ability to act as a long-term filter for runoff contaminants, and brings about operational matters regarding the most effective maintenance practices to enhance contaminant retention in SUDS. This paper reports the vertical extent of metal and PAH contamination in the soil of seven source-control devices in operation for more than 10 years, assessed via a two-step sampling strategy to optimize the representativeness of the contamination profiles. Metal distribution was typically characterized by a significant surface buildup, followed by a decrease in concentrations with increasing depth, usually coming close to the background values. PAH were more heterogeneously distributed with depth, but their accumulation was globally restricted to the upper 10-40 cm. This indicates an interesting potential for pollution interception by the upper horizons of soil, but does not necessarily prevent from downward fluxes, even while measuring low surface contents, as deeper strata may have lesser retention capacities. Specific amendments of the surface soil may help prevent this problem. Surface soil renewal - which would be necessary over 2.5-30 cm in four sites, according to the "strictest" standards for soil remediation - may regenerate the soil's sorption potential, but such a practice could disrupt the interactions with the local ecosystem, so this should be carried out exceptionally and not as a preventive measure. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using USDA's National Cooperative Soil Survey Soil Characterization Data to detect soil change: A cautionary tale

USDA-ARS?s Scientific Manuscript database

Recently, the USDA-NRCS National Cooperative Soil Survey Soil Characterization Database (NSCD) was reported to provide evidence that total nitrogen (TN) stocks of agricultural soils have increased across the Mississippi basin since 1985. Unfortunately, due to omission of metadata from the NSCD, hist...

40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

Code of Federal Regulations, 2013 CFR

2013-07-01

...) through (iv) of this section. (1)(i) The pH of the solid waste and soil mixture is 6.5 or greater at the.... (A) Soil cation exchange capacity (meq/100g) Maximum cumulative application (kg/ha) Background soil pH less than 6.5 Background soil pH more than 6.5 Less than 5 5 5 5 to 15 5 10 More than 15 5 20 (B...

40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

Code of Federal Regulations, 2014 CFR

2014-07-01

...) through (iv) of this section. (1)(i) The pH of the solid waste and soil mixture is 6.5 or greater at the.... (A) Soil cation exchange capacity (meq/100g) Maximum cumulative application (kg/ha) Background soil pH less than 6.5 Background soil pH more than 6.5 Less than 5 5 5 5 to 15 5 10 More than 15 5 20 (B...

40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

Code of Federal Regulations, 2012 CFR

2012-07-01

...) through (iv) of this section. (1)(i) The pH of the solid waste and soil mixture is 6.5 or greater at the.... (A) Soil cation exchange capacity (meq/100g) Maximum cumulative application (kg/ha) Background soil pH less than 6.5 Background soil pH more than 6.5 Less than 5 5 5 5 to 15 5 10 More than 15 5 20 (B...

Soil CO2 emissions as a proxy for heat and mass flow assessment, Taupō Volcanic Zone, New Zealand

USGS Publications Warehouse

Bloomberg, S.; Werner, Cynthia A.; Rissmann, C.F.; Mazot, A.; Horton, Travis B.; Gravley, D; Kennedy, B.; Oze, C

2014-01-01

The quantification of heat and mass flow between deep reservoirs and the surface is important for understanding magmatic and hydrothermal systems. Here, we use high-resolution measurement of carbon dioxide flux (φCO2) and heat flow at the surface to characterize the mass (CO2 and steam) and heat released to the atmosphere from two magma-hydrothermal systems. Our soil gas and heat flow surveys at Rotokawa and White Island in the Taupō Volcanic Zone, New Zealand, include over 3000 direct measurements of φCO2 and soil temperature and 60 carbon isotopic values on soil gases. Carbon dioxide flux was separated into background and magmatic/hydrothermal populations based on the measured values and isotopic characterization. Total CO2 emission rates (ΣCO2) of 441 ± 84 t d−1 and 124 ± 18 t d−1were calculated for Rotokawa (2.9 km2) and for the crater floor at White Island (0.3 km2), respectively. The total CO2 emissions differ from previously published values by +386 t d−1 at Rotokawa and +25 t d−1 at White Island, demonstrating that earlier research underestimated emissions by 700% (Rotokawa) and 25% (White Island). These differences suggest that soil CO2 emissions facilitate more robust estimates of the thermal energy and mass flux in geothermal systems than traditional approaches. Combining the magmatic/hydrothermal-sourced CO2 emission (constrained using stable isotopes) with reservoir H2O:CO2mass ratios and the enthalpy of evaporation, the surface expression of thermal energy release for the Rotokawa hydrothermal system (226 MWt) is 10 times greater than the White Island crater floor (22.5 MWt).

Comparing Background and Recent Erosion Rates in Degraded Areas of Southeastern Brazil

NASA Astrophysics Data System (ADS)

Fernandes, N.; Bierman, P. R.; Sosa-Gonzalez, V.; Rood, D. H.; Fontes, R. L.; Santos, A. C.; Godoy, J. M.; Bhering, S.

2014-12-01

Soil erosion is a major problem in northwestern Rio de Janeiro State where, during the last three centuries, major land-use changes took place, associated with the replacement of the original rainforest by agriculture and grazing. The combination of steep hillslopes, erodible soils, sparse vegetation, natural and human-induced fires, as well as downslope ploughing, led to an increase in surface runoff and surface erosion on soil-mantled hillslopes; together, these actions and responses caused a decline in soil productivity. In order to estimate changes in erosion rates over time, we compared erosion rates measured at different spatial and temporal scales, both background (natural) and short-term (human-induced during last few decades). Background long-term erosion rates were measured using in-situ produced cosmogenic 10Be in the sand fraction quartz of active river channel sediment in four basins in the northwestern portion of Rio de Janeiro State. In these basins, average annual precipitation varies from 1,200 to 1,300 mm, while drainage areas vary from 15 to 7,200 km2. Short-term erosion rates were measured in one of these basins from fallout 210Pb in soil samples collected along a hillslope transect located in an abandoned agriculture field. In this transect, 190 undisturbed soil samples (three replicates) were collected from the surface to 0.50 m depth (5 cm vertical intervals) in six soil pits. 10Be average background, basin-wide, erosion rates in the area are ~ 13 m/My; over the last decades, time-integrated (210Pb) average hillslope erosion rates are around 1450 m/Myr, with maximum values at the steepest portion of convex hillslopes of about 2000 m/Myr. These results suggest that recent hillslope erosion rates are about 2 orders of magnitude above background rates of sediment generation integrated over many millennia. This unsustainable rate of soil loss has severely decreased soil productivity eventually leading to the abandonment of farming activities in areas where soil loss is severe.

Characterization of Soil Moisture Level for Rice and Maize Crops using GSM Shield and Arduino Microcontroller

NASA Astrophysics Data System (ADS)

Gines, G. A.; Bea, J. G.; Palaoag, T. D.

2018-03-01

Soil serves a medium for plants growth. One factor that affects soil moisture is drought. Drought has been a major cause of agricultural disaster. Agricultural drought is said to occur when soil moisture is insufficient to meet crop water requirements, resulting in yield losses. In this research, it aimed to characterize soil moisture level for Rice and Maize Crops using Arduino and applying fuzzy logic. System architecture for soil moisture sensor and water pump were the basis in developing the equipment. The data gathered was characterized by applying fuzzy logic. Based on the results, applying fuzzy logic in validating the characterization of soil moisture level for Rice and Maize crops is accurate as attested by the experts. This will help the farmers in monitoring the soil moisture level of the Rice and Maize crops.

[Impact of industrial pollution on emission of carbon dioxide by soils in the Kola Subarctic Region].

PubMed

Koptsik, G N; Kadulin, M S; Zakharova, A I

2015-01-01

Soil emission of carbon dioxide, the key component of carbon cycle and the characteristic of soil biological activity, has been studied in background and polluted ecosystems in the Kola subarctic, the large industrial region of Russia. Long-term air pollution by emissions of "Pechenganikel" smelter, the largest source of sulphur dioxide and heavy metals in Northern Europe, has caused the technogenic digression of forest ecosystems. As a result of the digression, the tree layer was destructed, the number of plant species was diminished, the activity of soil biota was weakened, the soils were polluted and exhausted, biogeochemical cycles of elements were disturbed and productivity of ecosystems shrunk. Field investigations revealed the decrease of the in.situ soil respiration in average from 190-230 mg C-CO2/m2 x per h in background pine forests to 130-160, 100, and 20 mg C-CO2/m2.per h at the stages of pine defoliation, sparse pine forest and technogenic barrens of the technogenic succession, respectively. The soil respira- tion in birch forests was more intense than in pine forests and tended to decrease from about 290 mg C-CO2/m2 x per h in background forests to 210-220 and 170-190 mg C-CO2/m2 x per h in defoliating forests and technogenic sparse forests, respectively. Due to high spatial variability of soil respiration in both pine and birch forests significant differences from the background level were found only in technogenic sparse forests and barrens. Soil respiration represents total production of carbon dioxide by plant roots and soil microorganisms. The decrease in share of root respiration in the total soil respiration with the rise of pollution from 38-57% in background forests up to zero in technogenic barrens has been revealed for the first time for this region. This indicates that plants seem to be more sensitive to pollution as compared to relatively resistant microorganisms. Soil respiration and the contribution of roots to the total respiration positively correlated with distance from the smelter and the content of carbon and nitrogen and negatively correlated with the content of available nickel and copper in the soils. Remediation of technogenic barrens promoted intensification of soil biological activity. At the same time, the willow planting along with grass seeding into the new constructed fertile soil layer was much more effective for activation of soil respiration and the contribution of roots to the total respiration than the planting into the limed and fertilized polluted soils (chemo-phytostabilization).

Chemical and mineralogical composition of the Mongolian rural soils and their uranium sorption behavior.

PubMed

Tserenpil, Sh; Maslov, O D; Norov, N; Liu, Q C; Fillipov, M F; Theng, Benny K G; Belov, A G

2013-04-01

Distribution of uranium (VI) between soil solids and solutions is a key parameter in assessing the risk to the biosphere of disposing uranium-rich waste products from nuclear plants as well as uranium (U) ore mining. Both of these topics have recently been brought to public attention in Mongolia. Regional background levels of soil elements are an important dataset for accessing the actual environmental situation and monitoring pollution levels. Little information, however, is available on background concentrations of various elements in Mongolian soils. Thirteen rural soils were sampled from six provinces in Mongolia, and the concentrations of macro-, micro- and trace elements were measured. The values obtained served as a reference (baseline) for uncontaminated soils. The soils were characterized with slightly acidic to strongly alkaline pH values. With the exception of the sample from a western province, all the soils investigated contained little organic matter. The content of soil elements did not vary widely among geographical regions. The concentration of most micro elements was within the range of worldwide soil values but the value for Zn tended to be moderately higher. The U (VI) sorption into the soils was investigated using the batch technique and the (237)U radionuclide tracer, produced by the photo fission reaction (238)U(γ, n) (237)U at an electron accelerator. The (237)U distribution coefficient (K(d)), derived from the sorption isotherms, was related to solution pH and varying from 9 to 2547 mL g(-1) when the pH ranged between 3 and 7.7. The sorption process was interpreted in terms of the formation of different U (VI) species at given concentrations, calculated using the Speciation program with and without carbonate in the system. The U sorption isotherm displayed two general patterns: one where sorption decreased as solution pH increased, showing a maximum at pH 3, and another pattern revealed an adsorption maximum at pH 5 and then decreased up to pH 7.7 (the final solution pH). The observed decrease in K(d) when solution pH increased from 6 to 8 was consistent with the increased formation of soluble UO(2)(OH)(2) species. A linear negative correlation between lgK(d) and the solution pH was observed similarly to that reported for the soils with a pH ≥ 6. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of soil heavy metals for eco-environment and human health in a rapidly urbanization area of the upper Yangtze Basin.

PubMed

Jia, Zhongmin; Li, Siyue; Wang, Li

2018-02-19

Soil pollution with heavy metals (HMs) has been attracting more and more interests, however, assessment of eco-environmental and human risks particularly in a rapidly urbanization area (the upper Yangtze) remains limited. Multiple modern indices were firstly performed for complete risk assessment of eco-environment and human health based on a high-spatial-resolution sampling. Averages of HMs were far below grade II threshold level of the Chinese Environmental Quality standards for soils, whereas Cd, As and Hg considerably exceeded the local background values. EF suggested overall moderate enrichments of Cd and Se, resulting in soils uncontaminated to moderately contaminated with them. Potential ecological risk index showed significant differences among Counties that were characterized by moderate risk. However, several sites were moderately to heavily contaminated with As, Cd and Hg by Igeo, resulting in that these sites were categorized as "considerable risk", or "high risk". Moreover, children were more susceptible to the potential health risk irrespective of the carcinogenic or non - carcinogenic risk. There were no significant carcinogenic and non - carcinogenic risks for adults, children however showed significant non - carcinogenic effect. Our first assessment provided important information for policy making to reduce the potential effects of soil contamination on human and eco-environment.

GEMAS: Colours of dry and moist agricultural soil samples of Europe

NASA Astrophysics Data System (ADS)

Klug, Martin; Fabian, Karl; Reimann, Clemens

2016-04-01

High resolution HDR colour images of all Ap samples from the GEMAS survey were acquired using a GeoTek Linescan camera. Three measurements of dry and wet samples with increasing exposure time and increasing illumination settings produced a set of colour images at 50μm resolution. Automated image processing was used to calibrate the six images per sample with respect to the synchronously measured X-Rite colorchecker chart. The calibrated images were then fit to Munsell soil colours that were measured in the same way. The results provide overview maps of dry and moist European soil colours. Because colour is closely linked to iron mineralogy, carbonate, silicate and organic carbon content the results can be correlated to magnetic, mineralogical, and geochemical properties. In combination with the full GEMAS chemical and physical measurements, this yields a valuable data set for calibration and interpretation of visible satellite colour data with respect to chemical composition and geological background, soil moisture, and soil degradation. This data set will help to develop new methods for world-wide characterization and monitoring of agricultural soils which is essential for quantifying geologic and human impact on the critical zone environment. It furthermore enables the scientific community and governmental authorities to monitor consequences of climatic change, to plan and administrate economic and ecological land use, and to use the data set for forensic applications.

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

40 CFR 264.278 - Unsaturated zone monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... or operator must monitor the soil and soil-pore liquid to determine whether hazardous constituents... unsaturated zone monitoring system that includes soil monitoring using soil cores and soil-pore liquid... the quality of background soil-pore liquid quality and the chemical make-up of soil that has not been...

Average pollutant concentration in soil profile simulated with Convective-Dispersive Equation. Model and Manual

USDA-ARS?s Scientific Manuscript database

Different parts of soil solution move with different velocities, and therefore chemicals are leached gradually from soil with infiltrating water. Solute dispersivity is the soil parameter characterizing this phenomenon. To characterize the dispersivity of soil profile at field scale, it is desirable...

Distribution and speciation of metals in soils of the former mining district of Touiref (Northwest Tunisia)

NASA Astrophysics Data System (ADS)

Othmani, M. A.; Soussi, F.; Ferreira da Silva, E.; Moussi, A.; Oueslati, W.; Jebali, R.

2012-04-01

The former mining district of Touiref (1901-1958), located North-West of Tunisia, and where the activities have stopped 50 years ago, gave rise to large volumes of mine (extraction, flotation) tailings containing sulphides (galena, sphalerite, jordanite, pyrite, marcasite) associated with a carbonate gangue. Analysis of a hundred samples of soil has been used to develop isoconcentration maps of Pb, Zn, Cd and As across the study area, beyond the local geochemical background (LGB). The drawing of these maps has allowed the delineation of the contaminated areas using Geographic Information Systems (GIS). In addition, the soils of the study area were characterized in terms physico-chemical (pH and Corg), grain size, mineralogical and chemical means. Their neutral to slightly alkaline pH is (7.91 to 8.81), and their clay (32 and 57%)-silt (26 and 42%) texture, are characteristic of soils developed on carbonate bedrocks. The percentages in organic carbon (Corg) are between 0.71 and 5.6%. From a mineralogical point of view, mainly Pb-Fe sulphides associated with their alteration products have been observed within these soils. The levels of Pb, Zn, Cd and As, may go up 0.99%, 1.99%, 140 ppm and 409 ppm, respectively. These high concentrations were recorded around the extraction, processing and storage sites on the one hand and through the flood zones and the prevailing wind direction (NW-SSE) on the other. These soils have also been subjected to sequential extraction tests in order to characterize the metal-bearing phases and assess the mobility and bioavailability of heavy metals. The results have shown that Pb is mainly associated with the acid-soluble fraction (carbonates) and to a lesser extent with the Fe-(oxy)hydroxides, whereas Zn and Cd are mainly associated with Fe-(oxy)hydroxides and to a lesser degree with sulphides. Metals associated with these phases can be easily mobilized in response to physico-chemical changes and become phytoaccessible.

Monitoring of Soil Contamination by Heavy Metals in the Impact Zone of Copper-Nickel Smelter on the Kola Peninsula

NASA Astrophysics Data System (ADS)

Kashulina, G. M.

2018-04-01

The results of landscape monitoring of the concentrations of acid-extractable Ni, Cu, Co, Mn, and Zn in soils of the local impact zone of the Severonikel industrial complex on the Kola Peninsula are discussed. The aim of monitoring studies was to reveal the spatial and temporal regularities of variation in the degree of soil contamination by heavy metals. In 2001-2011, the concentrations of acid-extractable compounds of the elements in the upper part of organic soil horizons around this plant exceeded their background concentrations by two orders of magnitude for Cu and Co and by three orders of magnitude for Ni. The degree of topsoil contamination with Ni, Cu, and Co generally corresponded to the distance of the plots from the contamination source and to the modern technogenic load. However, because of the long period of the emissions, their extreme amounts, and complex composition, indirect factors—the degree of technogenic soil degradation, the loss of soil organic matter, saturation of the surface soil layers by the contaminating metals, and competitive relationships between the elements—also affect soil contamination level. The concentrations of all the studied metals in the topsoil are characterized by considerable (1.5 to 7 times) variability in their long-term dynamics. The most important factors of this variability for Ni, Cu, and Co are the organic matter content of the samples and the amount of atmospheric precipitation in the year preceding the sampling. An inverse relationship between element concentrations in the soils and the amount of atmospheric precipitation attests to the dynamic nature and reversible character of the accumulation of heavy metals in the soils.

The History of Electromagnetic Induction Techniques in Soil Survey

NASA Astrophysics Data System (ADS)

Brevik, Eric C.; Doolittle, Jim

2014-05-01

Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales.

Insights into the chemical partitioning of trace metals in roadside and off-road agricultural soils along two major highways in Attica's region, Greece.

PubMed

Botsou, Fotini; Sungur, Ali; Kelepertzis, Efstratios; Soylak, Mustafa

2016-10-01

We report in this study the magnetic properties and partitioning patterns of selected trace metals (Pb, Zn, Cu, Cd, Ni) in roadside and off-road (>200m distance from the road edge) agricultural soils collected along two major highways in Greece. Sequential extractions revealed that the examined trace metals for the entire data set were predominantly found in the residual fraction, averaging 37% for Cd up to 80% for Cu. Due to the strong influence of lithogenic factors, trace metal pseudototal contents of the roadside soils did not differ significantly to those of the off-road soils. Magnetic susceptibility and frequency dependent magnetic susceptibility determinations showed a magnetic enhancement of soils; however, it was primarily related to geogenic factors and not to traffic-derived magnetic particles. These results highlight that in areas characterized by strong geogenic backgrounds, neither pseudototal trace metal contents nor magnetic properties determinations effectively capture traffic-related contamination of topsoils. The vehicular emission signal was traced by the increased acid-soluble and reducible trace metal contents of the roadside soils compared to their off-road counterparts. In the case of Cu and Zn, changes in the partitioning patterns were also observed between the roadside and off-road soils. Environmental risks associated with agricultural lands extending at the margins of the studied highways may arise from the elevated Ni contents (both pseudototal and potentially mobile), and future studies should investigate Ni levels in the edible parts of plants grown on these agricultural soils. Copyright © 2016 Elsevier Inc. All rights reserved.

Biological activity of soddy-calcareous soils and cultural layers in Alanian settlements of the Kislovodsk basin

NASA Astrophysics Data System (ADS)

Chernysheva, E. V.; Kashirskaya, N. N.; Korobov, D. S.; Borisov, A. V.

2014-09-01

Microbiological investigations of cultural layers were performed in a settlement of the Alanian culture—Podkumskoe-2 (the 2nd-4th centuries AD). The present-day soddy-calcareous soils (rendzinas) used for different purposes were also studied near this settlement. The most significant changes in the initial characteristics of the soil microbial communities occurred under the residential influence more than 1500 years ago; these changes have been preserved until the present time. In the areas subjected to the anthropogenic impact, the total microbial biomass (the weighted average of 3720 μg C/g soil) was lower than that in the background soil. The minimal values of the microbial biomass were found in the soil of the pasture—2.5 times less than in the background soil. The urease activity of the cultural layer was higher than that of the soils nearby the settlement. Elevated values of the cellulose activity were also recorded only in the cultural layers. The current plowing has led to a significant decrease in the mycelium biomass of the microscopic fungi. In the soil of the fallow, the weighted average value of the fungal hyphae biomass along the profile was twice lower than that in the background soil and cultural layers of the settlement. The pasture first affected the active microbial biomass and, to a lesser extent, the amount of microscopic fungi.

40 CFR 265.278 - Unsaturated zone (zone of aeration) monitoring.

Code of Federal Regulations, 2012 CFR

2012-07-01

... soils nearby; this background monitoring must be conducted before or in conjunction with the monitoring... a minimum: (1) Soil monitoring using soil cores, and (2) Soil-pore water monitoring using devices... demonstrate in his unsaturated zone monitoring plan that: (1) The depth at which soil and soil-pore water...

40 CFR 265.278 - Unsaturated zone (zone of aeration) monitoring.

Code of Federal Regulations, 2011 CFR

2011-07-01

... soils nearby; this background monitoring must be conducted before or in conjunction with the monitoring... a minimum: (1) Soil monitoring using soil cores, and (2) Soil-pore water monitoring using devices... demonstrate in his unsaturated zone monitoring plan that: (1) The depth at which soil and soil-pore water...

40 CFR 265.278 - Unsaturated zone (zone of aeration) monitoring.

Code of Federal Regulations, 2010 CFR

2010-07-01

... soils nearby; this background monitoring must be conducted before or in conjunction with the monitoring... a minimum: (1) Soil monitoring using soil cores, and (2) Soil-pore water monitoring using devices... demonstrate in his unsaturated zone monitoring plan that: (1) The depth at which soil and soil-pore water...

40 CFR 265.278 - Unsaturated zone (zone of aeration) monitoring.

Code of Federal Regulations, 2014 CFR

2014-07-01

... soils nearby; this background monitoring must be conducted before or in conjunction with the monitoring... a minimum: (1) Soil monitoring using soil cores, and (2) Soil-pore water monitoring using devices... demonstrate in his unsaturated zone monitoring plan that: (1) The depth at which soil and soil-pore water...

40 CFR 265.278 - Unsaturated zone (zone of aeration) monitoring.

Code of Federal Regulations, 2013 CFR

2013-07-01

... soils nearby; this background monitoring must be conducted before or in conjunction with the monitoring... a minimum: (1) Soil monitoring using soil cores, and (2) Soil-pore water monitoring using devices... demonstrate in his unsaturated zone monitoring plan that: (1) The depth at which soil and soil-pore water...

Soils regulate and mitigate climate change

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: The interaction of soil science and ecology can be traced back to the origins of soil science as an independent discipline within the natural sciences. Vasili Dokuchaev, the founder of modern soil science, identified five soil forming factors: parent material, climate, o...

Temporal changes of spatial soil moisture patterns: controlling factors explained with a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Martini, Edoardo; Wollschläger, Ute; Kögler, Simon; Behrens, Thorsten; Dietrich, Peter; Reinstorf, Frido; Schmidt, Karsten; Weiler, Markus; Werban, Ulrike; Zacharias, Steffen

2016-04-01

Characterizing the spatial patterns of soil moisture is critical for hydrological and meteorological models, as soil moisture is a key variable that controls matter and energy fluxes and soil-vegetation-atmosphere exchange processes. Deriving detailed process understanding at the hillslope scale is not trivial, because of the temporal variability of local soil moisture dynamics. Nevertheless, it remains a challenge to provide adequate information on the temporal variability of soil moisture and its controlling factors. Recent advances in wireless sensor technology allow monitoring of soil moisture dynamics with high temporal resolution at varying scales. In addition, mobile geophysical methods such as electromagnetic induction (EMI) have been widely used for mapping soil water content at the field scale with high spatial resolution, as being related to soil apparent electrical conductivity (ECa). The objective of this study was to characterize the spatial and temporal pattern of soil moisture at the hillslope scale and to infer the controlling hydrological processes, integrating well established and innovative sensing techniques, as well as new statistical methods. We combined soil hydrological and pedological expertise with geophysical measurements and methods from digital soil mapping for designing a wireless soil moisture monitoring network. For a hillslope site within the Schäfertal catchment (Central Germany), soil water dynamics were observed during 14 months, and soil ECa was mapped on seven occasions whithin this period of time using an EM38-DD device. Using the Spearman rank correlation coefficient, we described the temporal persistence of a dry and a wet characteristic state of soil moisture as well as the switching mechanisms, inferring the local properties that control the observed spatial patterns and the hydrological processes driving the transitions. Based on this, we evaluated the use of EMI for mapping the spatial pattern of soil moisture under different hydrologic conditions and the factors controlling the temporal variability of the ECa-soil moisture relationship. The approach provided valuable insight into the time-varying contribution of local and nonlocal factors to the characteristic spatial patterns of soil moisture and the transition mechanisms. The spatial organization of soil moisture was controlled by different processes in different soil horizons, and the topsoil's moisture did not mirror processes that take place within the soil profile. Results show that, for the Schäfertal hillslope site which is presumed to be representative for non-intensively managed soils with moderate clay content, local soil properties (e.g., soil texture and porosity) are the major control on the spatial pattern of ECa. In contrast, the ECa-soil moisture relationship is small and varies over time indicating that ECa is not a good proxy for soil moisture estimation at the investigated site.Occasionally observed stronger correlations between ECa and soil moisture may be explained by background dependencies of ECa to other state variables such as pore water electrical conductivity. The results will help to improve conceptual understanding for hydrological model studies at similar or smaller scales, and to transfer observation concepts and process understanding to larger or less instrumented sites, as well as to constrain the use of EMI-based ECa data for hydrological applications.

Profile of a city: characterizing and classifying urban soils in the city of Ghent

NASA Astrophysics Data System (ADS)

Delbecque, Nele; Verdoodt, Ann

2017-04-01

Worldwide, urban lands are expanding rapidly. Conversion of agricultural and natural landscapes to urban fabric can strongly influence soil properties through soil sealing, excavation, leveling, contamination, waste disposal and land management. Urban lands, often characterized by intensive use, need to deliver many production, ecological and cultural ecosystem services. To safeguard this natural capital for future generations, an improved understanding of biogeochemical characteristics, processes and functions of urban soils in time and space is essential. Additionally, existing (inter)national soil classification systems, based on the identification of soil genetic horizons, do not always allow a functional classification of urban soils. This research aims (1) to gain insight into urban soils and their properties in the city of Ghent (Belgium), and (2) to develop a procedure to functionally incorporate urban soils into existing (inter)national soil classification systems. Undisturbed soil cores (depth up to 1.25 m) are collected at 15 locations in Ghent with different times since development and land uses. Geotek MSCL-scans are taken to determine magnetic susceptibility and gamma density and to obtain high resolution images. Physico-chemical characterization of the soil cores is performed by means of detailed soil profile descriptions, traditional lab analyses, as well as proximal soil sensing techniques (XRF). The first results of this research will be presented and critically discussed to improve future efforts to characterize, classify and evaluate urban soils and their ecosystem services.

Macroscopic and molecular-scale assessment of soil lead contamination impacted by seasonal dove hunting activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Arai, Y.; Tappero, R.; Rick, A.R.

Environmental contamination of lead (Pb) in soils and sediments poses serious threats to human and ecological health. The objective of this study is to investigate the effect of seasonal dove sports hunting activities on Pb contamination in acid forest soils. A grid sampling method was used to investigate the spatial distribution of Pb contamination in surface soils. Soils were analyzed for total metal(loid) concentration and characterized for physicochemical properties and mineralogy. Adsorption isotherm experiments were also conducted to understand the reactivity and retention capacity of Pb(II) in soils. Finally, synchrotron-based X-ray microprobe and X-ray absorption spectroscopy were used to understandmore » the chemical speciation of Pb that controls the retention/release mechanisms of Pb in soils. There was no excessive accumulation of Pb at the site. However, the concentration of Pb in surface soils was greater than the background level (<16 mg kg{sup -1}). The contamination level of Pb was as high as 67 mg kg{sup -1} near a patch of corn field where lime was frequently applied. A microfocused X-ray microprobe analysis showed the presence of Pb pellet fragments that predominantly contain oxidized Pb(II), suggesting that oxidative dissolution was occurring in soils. Dissolved Pb(II) can be readily retained in soils up to {approx}3,600 mg kg{sup -1} via inner-sphere and outer-sphere surface complexation on carbon and aluminol functional groups of soil components, suggesting that partitioning reactions control the concentration of Pb in soil solution. The fate of Pb is likely to be controlled by (1) oxidative dissolution process of Pb(0) pellets and (2) the release of outer-sphere and/or inner-sphere Pb surface complexes in humic substances and aluminosilicate/Al oxyhydroxides. Although no remedial actions are immediately required, the long-term accumulation of Pb in soils should be carefully monitored in protecting ecosystem and water quality at the dove hunting field.« less

Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

USGS Publications Warehouse

Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Sadowsky, M.J.; Ishii, S.

2006-01-01

The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

CHARACTERIZATION OF CHROMIUM-CONTAMINATED SOILS USING FIELD-PORTABLE X-RAY FLUORESCENCE

EPA Science Inventory

A detailed characterization of the underlying and adjacent soils near a chrome plating shop utilized field-portable X- ray fluorescence (XRF) as a screening tool. XRF permitted real-time acquisition of estimates for total metal content of soils. A trailer-mounted soil coring unit...

Sorption Equilibria of Vapor Phase Organic Pollutants on Unsaturated Soils and Soil Minerals

DTIC Science & Technology

1990-04-01

Sorbent Characterization .. ........ .......... 6 a. Description of Inorganic Solids and Soils. .... ........ 6 b. Moisture Content...compounds (TCE and toluene) is compared for a cored depth profile obtained from an unsaturated soil and for simulated profiles using inorganic solids. The...Sorbent Characterization a. Description of Inorganic Solids and Soils Inorganic solids were used for initial sorption studies to develop experimental

Mineralogical and Chemical Characterization of Lunar Highland Regolith: Lessons Learned from Mare Soils

NASA Technical Reports Server (NTRS)

Taylor, L. A.; Cahill, J. T.; Patchen, A.; Pieters, C.; Morris, R.; Keller, L. P.; McKay, D. S.

2001-01-01

The Lunar Soil Characterization Consortium has begun study of the <45 m fractions of ten representative highland soils, chosen for their contrasting maturities. Difficulties are addressed in the modal and chemical analyses of these highland soils. Additional information is contained in the original extended abstract.

Soil and Litter Animals.

ERIC Educational Resources Information Center

Lippert, George

1991-01-01

A lesson plan for soil study utilizes the Tullgren extraction method to illustrate biological concepts. It includes background information, equipment, collection techniques, activities, and references for identification guides about soil fauna. (MCO)

Field-deployable sniffer for 2,4-dinitrotoluene detection.

PubMed

Albert, K J; Myrick, M L; Brown, S B; James, D L; Milanovich, F P; Walt, D R

2001-08-01

A field-deployable instrument has been developed to detect low-level 2,4-dinitrotoluene (2,4-DNT) vapors. The system is based on previously developed artificial nose technology and employs an array of sensory materials attached to the distal tips of an optical fiber bundle. Both semiselective and nonspecific, cross-reactive sensors were employed. Each sensor within the array responds differentially to vapor exposure so the array's fluorescence response patterns are unique for each analyte. The instrument is computationally "trained" to discriminate target response patterns from nontarget and background environments. This detection system has been applied to detect 2,4-DNT, an analyte commonly detected on the soil surface above buried 2,4,6-trinitrotoluene (TNT) land mines, in spiked soil and aqueous and ground samples. The system has been characterized and demonstrated the ability to detect 120 ppb 2,4-DNT vapor in blind (unknown) humidified samples during a supervised field test.

Role of natural nanoparticles on the speciation of Ni in andosols of la Reunion

NASA Astrophysics Data System (ADS)

Levard, Clément; Doelsch, Emmanuel; Rose, Jérôme; Masion, Armand; Basile-Doelsch, Isabelle; Proux, Olivier; Hazemann, Jean-Louis; Borschneck, Daniel; Bottero, Jean-Yves

2009-08-01

Andosols on the island of Réunion have high nickel (Ni) concentrations due to the natural pedo-geochemical background. Enhanced knowledge of Ni speciation is necessary to predict the bioavailability and potential toxicity of this element. Ni speciation in these andosols, marked by the presence of high amounts of natural aluminosilicate nanoparticles, was investigated in two complementary systems: (i) In a soil sample—densimetric fractionation was first performed in order to separate the potential bearing phases, prior to Ni speciation characterization. (ii) In a synthetic sample—Ni reactivity with synthetic aluminosilicate nanoparticle analogs were studied. In both cases, Ni speciation was determined using X-ray absorption spectroscopy (XAS). The results revealed that Ni had the same local environment in both systems (natural and synthetic systems), and Ni was chemically linked to natural short-range ordered aluminosilicates or analogs. This complex represented about 75% of the total Ni in the studied soil.

Genotype and plant trait effects on soil CO2 efflux responses to altered precipitation in switchgrass

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods Global climate change models predict increasing drought during the growing season, which will alter many ecosystem processes including soil CO2 efflux (JCO2), with potential consequences for carbon retention in soils. Soil moisture, soil temperature and plant traits such...

Element concentrations in surface soils of the Coconino Plateau, Grand Canyon region, Coconino County, Arizona

USGS Publications Warehouse

Van Gosen, Bradley S.

2016-09-15

This report provides the geochemical analyses of a large set of background soils collected from the surface of the Coconino Plateau in northern Arizona. More than 700 soil samples were collected at 46 widespread areas, sampled from sites that appear unaffected by mineralization and (or) anthropogenic contamination. The soils were analyzed for 47 elements, thereby providing data on metal concentrations in soils representative of the plateau. These background concentrations can be used, for instance, for comparison to metal concentrations found in soils potentially affected by natural and anthropogenic influences on the Coconino Plateau in the Grand Canyon region of Arizona.The soil sampling survey revealed low concentrations for the metals most commonly of environmental concern, such as arsenic, cobalt, chromium, copper, mercury, manganese, molybdenum, lead, uranium, vanadium, and zinc. For example, the median concentrations of the metals in soils of the Coconino Plateau were found to be comparable to the mean values previously reported for soils of the western United States.

Assessment of Soil Water Composition in the Northern Taiga Coniferous Forests of Background Territories in the Industrially Developed Region

NASA Astrophysics Data System (ADS)

Lukina, N. V.; Ershov, V. V.; Gorbacheva, T. T.; Orlova, M. A.; Isaeva, L. G.; Teben'kova, D. N.

2018-03-01

The composition of soil water under coniferous forests of Murmansk oblast—an industrially developed region of northern Russia—was investigated. The studied objects were dwarf-shrub-green-moss spruce forests and dwarf-shrub-lichen pine forests on Al-Fe-humus podzols ( Albic Rustic Podzols) that are widespread in the boreal zone. The concentrations and removal of organic carbon performing the most important biogeochemical and pedogenic functions were estimated. The results proved significant intra- and inter-biogeocenotic variability in the composition of atmospheric depositions and soil water. Carbon removal with soil water from organic and mineral horizons within elementary biogeoareas (EBGA) under tree crowns was 2-5 and 2-3 times (in some cases, up to 10 times) greater than that in the intercrown areas, respectively. The lowest critical level of mineral nitrogen (0.2 mg/L) was, as a rule, exceeded in tree EBGAs contrary to intercrown areas. Concentrations of sulfates and heavy metals in water of tree EBGA were 3-5 times greater than those in inter-crown areas. Significant inter-biogeocenotic variations related to differences in the height of trees and tree stand density were found. It is argued that adequate characterization of biochemical cycles and assessment of critical levels of components in soil water of forest ecosystems should be performed with due account for the intra- and inter-biogeocenotic variability.

Contents and leachability of heavy metals (Pb, Cu, Sb, Zn, As) in soil at the Pantex firing range, Amarillo, Texas.

PubMed

Basunia, S; Landsberger, S

2001-10-01

Pantex firing range soil samples were analyzed for Pb, Cu, Sb, Zn, and As. One hundred ninety-seven samples were collected from the firing range and vicinity area. There was a lack of knowledge about the distribution of Pb in the firing range, so a random sampling with proportional allocation was chosen. Concentration levels of Pb and Cu in the firing range were found to be in the range of 11-4675 and 13-359 mg/kg, respectively. Concentration levels of Sb were found to be in the range of 1-517 mg/kg. However, the Zn and As concentration levels were close to average soil background levels. The Sn concentration level was expected to be higher in the Pantex firing range soil samples. However, it was found to be below the neutron activation analysis (NAA) detection limit of 75 mg/kg. Enrichment factor analysis showed that Pb and Sb were highly enriched in the firing range with average magnitudes of 55 and 90, respectively. Cu was enriched approximately 6 times more than the usual soil concentration levels. Toxicity characteristic leaching procedure (TCLP) was carried out on size-fractionated homogeneous soil samples. The concentration levels of Pb in leachates were found to be approximately 12 times higher than the U.S. Environmental Protection Agency (EPA) regulatory concentration level of 5 mg/L. Sequential extraction (SE) was also performed to characterize Pb and other trace elements into five different fractions. The highest Pb fraction was found with organic matter in the soil.

Ca and Sr in the landscapes of the East Transbaikalia

NASA Astrophysics Data System (ADS)

Ermakov, Vadim; Bech, Jaume; Gulyaeva, Ul'yana; Safonov, Vladimir; Kuz'mina, Natal'ya; Roca, Núria

2017-04-01

It is known that Sr is involved in bone formation, but high levels of this trace element in the environment is associated with the risk of manifestation of chondrodystrophia (Urov Kashin-Beck disease), strontium rickets and bone destruction. The aim of this work was comparative assessment of Ca-Sr relationships in the soil-plant complex of the Urov biogeochemical provinces of Eastern Transbaikalia and "control" areas. The basic research landfills located on the territory of the area between the rivers Argun and Shilka. The study territory belongs to the forest-steppe areas of the High-Amur Midlands. Ca and Sr in soils were determined by X-ray fluorescence spectroscopy. The content of this chemical elements in plants (hay harvest) were measured by means of AAS. It was found that the content of Ca in soils, waters and plants of endemic Urov disease territories is approaching the concentrations of this macroelement in the objects of "background" areas. Sr concentrations are increased in the soil-plant complex of the Urov biogeochemical province and characterized by "spotting. It was found that the most frequently occurring ratio of Ca and Sr in the soils of some areas without the manifestation of osteoarticular pathologies in animals and humans varies from 11 to 236 units (53±24). In soils of Eastern Transbaikalia in the areas of distribution Urov Kashin-Beck disease, this ratio varies from 2 to 98 (36±11). The high content of strontium in the soil of the Urov biogeochemical province correlated with the concentration of this trace element in rocks.

Spatial distribution and sources of heavy metals in natural pasture soil around copper-molybdenum mine in Northeast China.

PubMed

Wang, Zhiqiang; Hong, Chen; Xing, Yi; Wang, Kang; Li, Yifei; Feng, Lihui; Ma, Silu

2018-06-15

The characterization of the content and source of heavy metals are essential to assess the potential threat of metals to human health. The present study collected 140 topsoil samples around a Cu-Mo mine (Wunugetushan, China) and investigated the concentrations and spatial distribution pattern of Cr, Ni, Zn, Cu, Mo and Cd in soil using multivariate and geostatistical analytical methods. Results indicated that the average concentrations of six heavy metals, especially Cu and Mo, were obviously higher than the local background values. Correlation analysis and principal component analysis divided these metals into three groups, including Cr and Ni, Cu and Mo, Zn and Cd. Meanwhile, the spatial distribution maps of heavy metals indicated that Cr and Ni in soil were no notable anthropogenic inputs and mainly controlled by natural factors because their spatial maps exhibited non-point source contamination. The concentrations of Cu and Mo gradually decreased with distance away from the mine area, suggesting that human mining activities may be crucial in the spreading of contaminants. Soil contamination of Zn were associated with livestock manure produced from grazing. In addition, the environmental risk of heavy metal pollution was assessed by geo-accumulation index. All the results revealed that the spatial distribution of heavy metals in soil were in agreement with the local human activities. Investigating and identifying the origin of heavy metals in pasture soil will lay the foundation for taking effective measures to preserve soil from the long-term accumulation of heavy metals. Copyright © 2018 Elsevier Inc. All rights reserved.

Environmental DNA sequencing primers for eutardigrades and bdelloid rotifers

PubMed Central

2009-01-01

Background The time it takes to isolate individuals from environmental samples and then extract DNA from each individual is one of the problems with generating molecular data from meiofauna such as eutardigrades and bdelloid rotifers. The lack of consistent morphological information and the extreme abundance of these classes makes morphological identification of rare, or even common cryptic taxa a large and unwieldy task. This limits the ability to perform large-scale surveys of the diversity of these organisms. Here we demonstrate a culture-independent molecular survey approach that enables the generation of large amounts of eutardigrade and bdelloid rotifer sequence data directly from soil. Our PCR primers, specific to the 18s small-subunit rRNA gene, were developed for both eutardigrades and bdelloid rotifers. Results The developed primers successfully amplified DNA of their target organism from various soil DNA extracts. This was confirmed by both the BLAST similarity searches and phylogenetic analyses. Tardigrades showed much better phylogenetic resolution than bdelloids. Both groups of organisms exhibited varying levels of endemism. Conclusion The development of clade-specific primers for characterizing eutardigrades and bdelloid rotifers from environmental samples should greatly increase our ability to characterize the composition of these taxa in environmental samples. Environmental sequencing as shown here differs from other molecular survey methods in that there is no need to pre-isolate the organisms of interest from soil in order to amplify their DNA. The DNA sequences obtained from methods that do not require culturing can be identified post-hoc and placed phylogenetically as additional closely related sequences are obtained from morphologically identified conspecifics. Our non-cultured environmental sequence based approach will be able to provide a rapid and large-scale screening of the presence, absence and diversity of Bdelloidea and Eutardigrada in a variety of soils. PMID:20003362

Interpreting, measuring, and modeling soil respiration

Treesearch

Michael G. Ryan; Beverly E. Law

2005-01-01

This paper reviews the role of soil respiration in determining ecosystem carbon balance, and the conceptual basis for measuring and modeling soil respiration. We developed it to provide background and context for this special issue on soil respiration and to synthesize the presentations and discussions at the workshop. Soil respiration is the largest component of...

40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

Code of Federal Regulations, 2011 CFR

2011-07-01

...) through (iv) of this section. (1)(i) The pH of the solid waste and soil mixture is 6.5 or greater at the...H less than 6.5 Background soil pH more than 6.5 Less than 5 5 5 5 to 15 5 10 More than 15 5 20 (B) For soils with a background pH of less than 6.5, the cumulative cadmium application rate does not...

40 CFR 257.3-5 - Application to land used for the production of food-chain crops (interim final).

Code of Federal Regulations, 2010 CFR

2010-07-01

...) through (iv) of this section. (1)(i) The pH of the solid waste and soil mixture is 6.5 or greater at the...H less than 6.5 Background soil pH more than 6.5 Less than 5 5 5 5 to 15 5 10 More than 15 5 20 (B) For soils with a background pH of less than 6.5, the cumulative cadmium application rate does not...

Soil Physical, Chemical, and Thermal Characterization, Teller Road Site, Seward Peninsula, Alaska, 2016

DOE Data Explorer

Graham, David; Kholodov, Alexander; Wilson, Cathy; Moon, Ji-Won; Romanovsky, Vladimir; Busey, Bob

2018-02-05

This dataset provides the results of physical, chemical, and thermal characterization of soils at the Teller Road Site, Seward Peninsula, Alaska. Soil pits were dug from 7-14 September 2016 at designated Intensive Stations 2 through 9 at the Teller Road MM 27 Site. This dataset includes field observations and descriptions of soil layers or horizons, field measurements of soil volumetric water content, soil temperature, thermal conductivity, and heat capacity. Laboratory measurements of soil properties include gravimetric water content, bulk density, volumetric water content, and total carbon and nitrogen.

Soil Physical, Chemical, and Thermal Characterization, Council Road Site, Seward Peninsula, Alaska, 2016

DOE Data Explorer

Alexander Kholodov; David Graham; Ji-Won Moon

2018-01-22

This dataset provides the results of physical, chemical, and thermal characterization of soils at the Council Road Site at MM71, Seward Peninsula, Alaska. Soil pits were dug on 11 September 2016 at three sites. This dataset includes field observations and descriptions of soil layers or horizons, field measurements of soil volumetric water content, soil temperature, thermal conductivity, and heat capacity. Laboratory measurements of soil properties include gravimetric water content, bulk density, volumetric water content, total carbon and nitrogen, and elemental composition from X-ray fluorescence for some elements.

Testing fungistatic properties of soil-like substrate for growing plants in bioregenerative life support systems

NASA Astrophysics Data System (ADS)

Enzhu, Hu; Nesterenko, Elena; Liu, Professor Hong; Manukovsky, N. S.; Kovalev, Vladimir; Gurevich, Yu.; Kozlov, Vladimir; Khizhnyak, Serge; Xing, Yidong; Hu, Enzhu; Enzhu, Hu

There are two ways of getting vegetable food in BLSS: in hydroponic culture and on soil substrates. In any case there is a chance that the plants will be affected by plant pathogenic microorganisms. The subject of the research was a soil-like substrate (SLS) for growing plants in a Bioregenerative Life Support System (BLSS). We estimated the fungistatic properties of SLS using test cultures of Bipolaris and Alternaria plant pathogenic fungi. Experiments were made with the samples of SLS, natural soil and sand (as control). We tested 2 samples of SLS produced by way of bioconversion of wheat and rice straw. We measured the disease severity of wheat seedlings and the incidence of common root rot in natural (non-infectious) background and man-made (infectious) conditions. The severity of disease on the SLS was considerably smaller both in non-infectious and infectious background conditions (8 and 12%) than on the natural soil (18 and 32%) and sand. It was the soil-like substrate that had the minimal value among the variants being compared (20% in non-infectious and 40% in infectious background conditions). This index in respect of the soil was 55 and 78%, correspondingly, and in respect of the sand - 60%, regardless of the background. It was found that SLS significantly suppressed conidia germination of Bipolaris soroikiniana (p<0.001). In the presence of SLS germination of conidia decreased to 9.9 - 12.2% of the control value. No significant differences were found between SLS samples obtained from wheat and rice straw.

Linking tephrochronology and soil characteristics in the Sila and Nebrodi Mountains, Italy

NASA Astrophysics Data System (ADS)

Raab, Gerald; Halpern, Dieter; Scarciglia, Fabio; Raimondi, Salvatore; de Castro Portes, Raquel; Norton, Kevin; Egli, Markus

2017-04-01

Mediterranean soils are an important key to understanding past volcanic events and landscape evolution. The influence and timing of Quaternary volcanic events on soils, however, remains still poorly understood in southern Italy. We used a multi-method approach to explore the origin and age of volcanic deposits (soils) in Sicily and Calabria. By comparing the geochemical signature of the soils with the chemical fingerprint of magmatic effusive rocks in southern Italy, we tried to identify the source material. It seems that the investigated soils on the Nebrodi (Sicily) and Sila (Calabria) mountains were both influenced by volcanic deposits having a high-K calc-alkaline series volcanic background. The Aeolian islands (Lipari and Vulcano) are the most likely sources of origin. Due to weathering processes of the volcanic sediments and the partial mixing with the underlying non-volcanic parent material, a direct relation with the potential source areas was not always straightforward. Immobile elements and their corresponding ratios (e.g. the Nb/Y vs Zr/Ti plot) or trace elements (Co, Th) and rare earth elements gave better hints of the origin of the deposits. Radiocarbon dating of the stable soil organic fraction (H2O2 resistant) indicated a minimum age of 8 - 10 ka of the Nebrodi and Sila soils. The chemical proxy of alteration (CPA) and weathering index according to Parker (WIP) were tested as proxies for an age estimate of the volcanic deposits and duration of soil formation. The soils and, subsequently, landscape are characterized by multiple volcanic depositional phases for the last 30 - 50 ka in the Sila mountains and about 70 ka in the Nebrodi mountains. We show that a multi-method approach (numerical dating, relative dating using weathering indices and the forensic procedure) enabled the identification of potential source areas, gave tentative age estimates of the ash deposits, duration of soil formation and, therefore, improved our understanding of volcanic landscape evolution.

Microbial Community Diversities and Taxa Abundances in Soils along a Seven-Year Gradient of Potato Monoculture Using High Throughput Pyrosequencing Approach

PubMed Central

Liu, Xing; Zhang, Junlian; Gu, Tianyu; Zhang, Wenming; Shen, Qirong; Yin, Shixue; Qiu, Huizhen

2014-01-01

Background Previous studies have focused on linking soil community structure, diversity, or specific taxa to disturbances. Relatively little attention has been directed to crop monoculture soils, particularly potato monoculture. Information about microbial community changes over time between monoculture and non-monoculture treatments is lacking. Furthermore, few studies have examined microbial communities in potato monoculture soils using a high throughput pyrosequencing approach. Methodology/Principal Findings Soils along a seven-year gradient of potato monoculture were collected and microbial communities were characterized using high throughput pyrosequencing approach. Principal findings are as follows. First, diversity (H Shannon) and richness (S Chao1) indices of bacterial community, but not of fungal community, were linearly decreased over time and corresponded to a decline of soil sustainability represented by yield decline and disease incidence increase. Second, Fusarium, the only soilborne pathogen-associated fungal genus substantially detected, was linearly increased over time in abundance and was closely associated with yield decline. Third, Fusarium abundance was negatively correlated with soil organic matter (OM) and total nitrogen (TN) but positively with electrical conductivity (EC). Fourth, Fusarium was correlated in abundances with 6 bacterial taxa over time. Conclusions Soil bacterial and fungal communities exhibited differential responses to the potato monoculture. The overall soil bacterial communities were shaped by potato monoculture. Fusarium was the only soilborne pathogen-associated genus associated with disease incidence increase and yield decline. The changes of soil OM, TN and EC were responsible for Fusarium enrichment, in addition to selections by the monoculture crop. Acidobacteria and Nitrospirae were linearly decreased over time in abundance, corresponding to the decrease of OM, suggesting their similar ecophysiologial trait. Correlations between abundance of Fusarium with several other bacterial taxa suggested their similar behaviors in responses to potato monoculture and/or soil variables, providing insights into the ecological behaviors of these taxa in the environment. PMID:24497959

A Novel Method for Analyzing Microbially Affiliated Volatile Organic Compounds in Soil Environments

NASA Astrophysics Data System (ADS)

Ruhs, C. V.; McNeal, K. S.

2010-12-01

A concerted, international effort by citizens, governments, industries and educational systems is necessary to address the myriad environmental issues that face us today. The authors of this paper concentrate on soil environments and, specifically, the methods currently used to characterize them. The ability to efficiently and effectively monitor and characterize various soils is desired, allows for the study, supervision, and protection of natural and cultivated ecosystems, and may assist stakeholders in meeting governmentally-imposed environmental standards. This research addresses soil characterization by a comparison of four methods that emphasize a combination of microbial community and metabolic measures: BIOLOG, fatty acid methyl-ester analysis (FAME), descriptive physical and chemical analysis (moisture content, pH, carbon content, nutrient content, and grain size), and the novel soil-microbe volatile organic compound analysis (SMVOC) presented in this work. In order to achieve the method comparison, soils were collected from three climatic regions (Bahamas, Michigan, and Mississippi), with three samples taken from niche ecosystems found at each climatic region (a total of nine sites). Of interest to the authors is whether or not an investigation of microbial communities and the volatile organic compounds (VOCs) produced by microbial communities from nine separate soil ecosystems provides useful information about soil dynamics. In essence, is analysis of soil-derived VOCs using gas chromatography-mass spectrometry (GC-MS) an effective method for characterizing microbial communities and their metabolic activity of soils rapidly and accurately compared with the other three traditional characterization methods? Preliminary results suggest that VOCs in each of these locales differ with changes in soil types, soil moisture, and bacterial community. Each niche site shows distinct patterns in both VOCs and BIOLOG readings. Results will be presented to show the efficacy of the SMVOC approach and the statistical alignment of the VOC and community measures.

Correlations between soil magnetic susceptibility and the content of particular elements as a reflection of pollution level, land use and parent rocks

NASA Astrophysics Data System (ADS)

Rachwał, Marzena; Magiera, Tadeusz; Bens, Oliver; Kardel, Kati

2015-04-01

Magnetic susceptibility is a worldwide used measure of (ferri)magnetic minerals occurring in soils, sediments and dusts. In soils, these minerals are of various origin: air-derived particulate pollutions, parent rocks or pedogenesis. Human activity causes different changes in the content of magnetic minerals as well as their spatial and vertical distribution in soil profiles. Magnetic minerals are characterized by an affinity for other elements occurring in the soil, so positive correlations between magnetic susceptibility and particular elements like macrocomponents or heavy metals often occurs. The archival soil samples collected from different soil horizons in the territory of the Free State of Saxony (Germany) were subjected to the magnetic susceptibility measurements using Bartington MS2B. Additionally, samples were chemically analyzed by the S Helmholtz Centre Potsdam, GFZ German Research Centre for Geosciences in Potsdam. Values of magnetic susceptibility varied from 9.3 to 1382 ×10-8 m3/kg in organic soil horizon and from 0.1 to 2105 ×10-8 m3/kg in dipper layers. Calculated correlation coefficients between magnetic susceptibility and some elements indicate significant relationships characteristic for different factors influenced soil properties (pollution level, land use and parent rocks). The northern part of Saxony is divided by the Elbe into two parts: east part with loose sedimentary rocks and the west one with more solid loess bedrock enriched by spectrum of elements from the Ore Mountains. Correlations between magnetic susceptibility and Ca, Fe, Mn, and Zn were stated in the eastern, while soil magnetic susceptibility of the western part revealed a correlation with Fe, P, Cd, Cu, Pb, Zn, Mo, U, V, and W. Taking into account influences of industry and urbanization, soil magnetic susceptibility is enhanced in the areas with higher population density comparing with rural sites. In the area of Hoyerswerda and Weisswasser with low magnetic natural background (sand) the load of (ferri)magnetic minerals explained by high magnetic susceptibility values as a result of high pollution level, shows the considerable correlations with Na, Ca, Fe, Mn, Zn, B, Be, V. What is more, the soil magnetic susceptibility, developed on different geological bedrocks, correlates with their natural geochemistry bound in the rock and connected with their ferromagnetic minerals (such magnetite and titanomagnetite present in slate, phyllite, mica schist). In that case the magnetic susceptibility correlates with such elements as: Fe, Mn, Ni, B and V. The soils in the south-eastern Saxony close to the border tri-point of Germany, Poland and the Czech Republic, reveal a correlation of magnetic susceptibility with Cd and As content. It can also be caused by power industry in Zittau, however they are developed on basalts and phonolithes in background that produce also strong magnetic signal of geogenic origin. All the statements made above are usually not so clear, since geogenic processes and anthropogenic influences often overlay in the soil.

A Novel Method for Measurement and Characterization of Soil Macroporosity

Treesearch

Christopher Barton; Tasos Karathanasis

2002-01-01

Quantitative macropore characterizations were performed in large zero-tension soil lysimeters of a Maury silt loam (fine, mixed, mesic Typic Paleudalf) and a Loradale silt loam (fine, silty, mixed, mesic Typic Axgiudoll) soil in an effort to assess potential colloid transport. Steel pipe sections (50 cm diameter X 100 cm length) were hydraulically driven into the soil...

A Brief History of the use of Electromagnetic Induction Techniques in Soil Survey

NASA Astrophysics Data System (ADS)

Brevik, Eric C.; Doolittle, James

2017-04-01

Electromagnetic induction (EMI) has been used to characterize the spatial variability of soil properties since the late 1970s. Initially used to assess soil salinity, the use of EMI in soil studies has expanded to include: mapping soil types; characterizing soil water content and flow patterns; assessing variations in soil texture, compaction, organic matter content, and pH; and determining the depth to subsurface horizons, stratigraphic layers or bedrock, among other uses. In all cases the soil property being investigated must influence soil apparent electrical conductivity (ECa) either directly or indirectly for EMI techniques to be effective. An increasing number and diversity of EMI sensors have been developed in response to users' needs and the availability of allied technologies, which have greatly improved the functionality of these tools and increased the amount and types of data that can be gathered with a single pass. EMI investigations provide several benefits for soil studies. The large amount of georeferenced data that can be rapidly and inexpensively collected with EMI provides more complete characterization of the spatial variations in soil properties than traditional sampling techniques. In addition, compared to traditional soil survey methods, EMI can more effectively characterize diffuse soil boundaries and identify included areas of dissimilar soils within mapped soil units, giving soil scientists greater confidence when collecting spatial soil information. EMI techniques do have limitations; results are site-specific and can vary depending on the complex interactions among multiple and variable soil properties. Despite this, EMI techniques are increasingly being used to investigate the spatial variability of soil properties at field and landscape scales. The future should witness a greater use of multiple-frequency and multiple-coil EMI sensors and integration with other sensors to assess the spatial variability of soil properties. Data analysis will be improved with advanced processing and presentation systems and more sophisticated geostatistical modeling algorithms will be developed and used to interpolate EMI data, improve the resolution of subsurface features, and assess soil properties.

Source identification and exchangeability of heavy metals accumulated in vegetable soils in the coastal plain of eastern Zhejiang province, China.

PubMed

Qiutong, Xu; Mingkui, Zhang

2017-08-01

Vegetable production in China is suffering increasingly heavy metal damages from various pollution sources including agricultural, industrial and other activities. It is of practical significance to understand the effects of human activities on the accumulation and exchangeability of soil heavy metals in vegetable fields. In this study, seventy-two arable layer samples of vegetable soils were collected from the Shaoxing coastal plain, a representative region of the coastal plain of eastern Zhejiang province, China for characterizing the effects of fertilization methods on accumulation and exchangeable heavy metals in soils (Exchangeable heavy metals in the soil samples were extracted by 0.01molL -1 CaCl 2 ). The different origins of heavy metals in the vegetable soils were investigated by multivariate statistical techniques, including principal component analysis (PCA) and cluster analysis (CA). Marked increases were noted for soil heavy metals due to long-term manure or chemical fertilizer application. Three significant components were extracted by PCA, explaining 78.86% of total variance. Mn, Co, Ni, Fe, and Al were associated in lithogenic components, while an anthropogenic origin was identified for Cu, Cr, Pb, Zn, Cd, Hg. However, As level was due to the geochemical background and was not linked to soil management. The results obtained by cluster analysis elucidated individual relationships between metals and agreed with PCA. Cu, Cr, Pb, and Zn in the soils that were mainly associated with the application of chemical fertilizers, organic manures or other activities regarding soil management. Although the origin of Cd, Hg, and As was also attributed to soil management, other sources like vehicle exhaust or aerial depositions were not discarded as possible contributors. Soil amended with organic fertilizer contained more Cu, Pb, Zn and Cr; whereas the soil amended with chemical fertilizer had more Cd. Application of fertilizers also had significant effect on the concentrations of exchangeable heavy metals. Higher mean concentrations of exchangeable Cd and Pb were found in the soils amended with chemical fertilizers, while those of exchangeable Cu and Zn were found in the soils amended with organic fertilizers. Copyright © 2017 Elsevier Inc. All rights reserved.

Ecotoxicological study of arsenic and lead contaminated soils in former orchards at the Hanford Site, USA.

PubMed

Delistraty, Damon; Yokel, Jerry

2014-01-01

The purpose of this study was to assess ecotoxicity of former orchard soils contaminated with lead arsenate pesticides at the Hanford Site in Washington state (USA). Surface soil, plant, and invertebrate samples were collected from 11 sites in former orchard areas. Mean (standard deviation [SD]) for As and Pb in soil were 39.5 (40.6) and 208 (142) mg/kg dry wt, respectively (n = 11). These concentrations exceeded Hanford background levels but were similar to orchard soils elsewhere. In our study, As and Pb soil concentrations were positively and significantly correlated (r = 0.87, Bonferroni P < 0.05). Speciation of total inorganic As in soil (n = 6) demonstrated that As+5 was the dominant form (>99%). Mean (SD) for As and Pb in cheatgrass were 3.9 (7.9) and 12.4 (20.0) mg/kg dry wt, respectively (n = 11), while mean (SD) for As and Pb in darkling beetles were 5.4 (2.6) and 3.9 (3.0) mg/kg dry wt, respectively (n = 8). Linear regressions were constructed to estimate soil to cheatgrass and soil to darkling beetle uptake for As and Pb. These were significant (Bonferroni P < 0.05) only for cheatgrass versus soil (As) and darkling beetle versus soil (Pb). Standardized lettuce seedling and earthworm bioassays were performed with a subset of soil samples (n = 6). No significant effects (P > 0.05) were observed in lettuce survival or growth nor in earthworm survival or sublethal effects. Based on these bioassays, unbounded no observed effect concentrations (NOECs) in soil for As and Pb were 128 and 390 mg/kg dry wt, respectively. However, our range of soil concentrations generally overlapped a set of ecotoxicological benchmarks reported in the literature. Given uncertainty and limited sampling related to our NOECs, as well as uncertainty in generic benchmarks from the literature, further study is needed to refine characterization of As and Pb ecotoxicity in former orchard soils at the Hanford Site. Copyright © 2011 Wiley Periodicals, Inc.

Vertical distribution of the soil microbiota along a successional gradient in a glacier forefield.

PubMed

Rime, Thomas; Hartmann, Martin; Brunner, Ivano; Widmer, Franco; Zeyer, Josef; Frey, Beat

2015-03-01

Spatial patterns of microbial communities have been extensively surveyed in well-developed soils, but few studies investigated the vertical distribution of micro-organisms in newly developed soils after glacier retreat. We used 454-pyrosequencing to assess whether bacterial and fungal community structures differed between stages of soil development (SSD) characterized by an increasing vegetation cover from barren (vegetation cover: 0%/age: 10 years), sparsely vegetated (13%/60 years), transient (60%/80 years) to vegetated (95%/110 years) and depths (surface, 5 and 20 cm) along the Damma glacier forefield (Switzerland). The SSD significantly influenced the bacterial and fungal communities. Based on indicator species analyses, metabolically versatile bacteria (e.g. Geobacter) and psychrophilic yeasts (e.g. Mrakia) characterized the barren soils. Vegetated soils with higher C, N and root biomass consisted of bacteria able to degrade complex organic compounds (e.g. Candidatus Solibacter), lignocellulolytic Ascomycota (e.g. Geoglossum) and ectomycorrhizal Basidiomycota (e.g. Laccaria). Soil depth only influenced bacterial and fungal communities in barren and sparsely vegetated soils. These changes were partly due to more silt and higher soil moisture in the surface. In both soil ages, the surface was characterized by OTUs affiliated to Phormidium and Sphingobacteriales. In lower depths, however, bacterial and fungal communities differed between SSD. Lower depths of sparsely vegetated soils consisted of OTUs affiliated to Acidobacteria and Geoglossum, whereas depths of barren soils were characterized by OTUs related to Gemmatimonadetes. Overall, plant establishment drives the soil microbiota along the successional gradient but does not influence the vertical distribution of microbiota in recently deglaciated soils. © 2014 John Wiley & Sons Ltd.

Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

NASA Astrophysics Data System (ADS)

Jafery, Khawarizmi Mohd; Embong, Zaidi; Khee, Yee See; Haimi Dahlan, Samsul; Tajudin, Saiful Azhar Ahmad; Ahmad, Salawati; Kudnie Sahari, Siti; Maxwell, Omeje

2018-01-01

The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong-Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka-Tavy, Harimau Tampoi, Kulai-Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ± 26.28 μR hr-1 and 7 ± 0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern of dielectric measurement for every soil at the frequency above 600 MHz demonstrated a specific distribution which can be classified into two main regions which are higher and lower between the ranges of 1.83 to 2.35. Pearson correlation analysis between the frequency of 100 MHz and 2.6 GHz with respect to exposure rate for every soil species was r = 0.38 and r = 0.51, respectively. This indicates that there was no strong correlation between both parameter, natural background dose and soils dielectric for each soils sample. This factor could be contributed by major and minor elements contained in each soils sample species, especially Ferum, Fe and Silica, Si.

Agroecological evaluation of the principal microelements content in Chernozems at the Central Chernozemic Region of Russia

NASA Astrophysics Data System (ADS)

Lukin, Sergey; Vasenev, Ivan

2015-04-01

The ecological evaluation of the principal microelements content in soil cover of the agroecosystems is the important issue of the regional agroecological monitoring which results are actively used for landscape-adaptive land-use design with rational, environmental friendly fertilizing systems. The virgin forest-steppe plots without anthropogenous impacts are usually used as background data of microelements content in dominated zonal Chernozems. The average background content of zinc, copper, cobalt and manganese mobile forms (extracted with рН 4,8 buffer) in 10-20 cm layer of virgin Leached Chernozem at the federal reserve «Belogorye» (monitoring site «Jamskaya Steppe») are accordingly 0.75, 0.19, 0.14 and 12.8 mg/kg. According to RF actual evaluation scale for arable soils the background microelements content in the investigated virgin Chernozems have been corresponded to low level for mobile forms of zinc, copper and cobalt, and to middle level - for manganese ones that essentially limits their natural fertility. The results of carried out in the Belgorod Region in 2010-2014 agroecological monitoring have shown, that most of the arable soils are characterized by low content of the mobile forms of manganese (60 %) zinc (99,2 % of total area), cobalt (94,1 %) and copper (100 %) too that became a serious problem for intensive farming active development in the region. During active agroecological monitoring period since 1990-1994 to 2010-2014 the average regional contents of the principal microelements mobile forms have been essentially decreased: from 1,44 to 0,53 mg/kg in case of zinc, from 17,5 to 9,2 mg/kg in case of manganese - due to low level of micronutrient fertilizers and manure application. It determined the current priority in the agrochemical service development in the region with new DSS-supported agrotechnologies design and essentially increased level of profitable application of traditional and non-traditional organic and mineral-organic fertilizers.

Health risk characterization of maximum legal exposures for persistent organic pollutant (POP) pesticides in residential soil: An analysis.

PubMed

Li, Zijian

2018-01-01

Regulations for pesticides in soil are important for controlling human health risk; humans can be exposed to pesticides by ingesting soil, inhaling soil dust, and through dermal contact. Previous studies focused on analyses of numerical standard values for pesticides and evaluated the same pesticide using different standards among different jurisdictions. To understand the health consequences associated with pesticide soil standard values, lifetime theoretical maximum contribution and risk characterization factors were used in this study to quantify the severity of damage using disability-adjusted life years (DALYs) under the maximum "legal" exposure to persistent organic pollutant (POP) pesticides that are commonly regulated by the Stockholm Convention. Results show that computed soil characterization factors for some pesticides present lognormal distributions, and some of them have DALY values higher than 1000.0 per million population (e.g., the DALY for dichlorodiphenyltrichloroethane [DDT] is 14,065 in the Netherlands, which exceeds the tolerable risk of uncertainty upper bound of 1380.0 DALYs). Health risk characterization factors computed from national jurisdictions illustrate that values can vary over eight orders of magnitude. Further, the computed characterization factors can vary over four orders of magnitude within the same national jurisdiction. These data indicate that there is little agreement regarding pesticide soil regulatory guidance values (RGVs) among worldwide national jurisdictions or even RGV standard values within the same jurisdiction. Among these POP pesticides, lindane has the lowest median (0.16 DALYs) and geometric mean (0.28 DALYs) risk characterization factors, indicating that worldwide national jurisdictions provide relatively conservative soil RGVs for lindane. In addition, we found that some European nations and members of the former Union of Soviet Socialist Republics share the same pesticide RGVs and data clusters for the computed characterization factors. Copyright © 2017 Elsevier Ltd. All rights reserved.

Endosulfan, pentachlorobenzene and short-chain chlorinated paraffins in background soils from Western Europe.

PubMed

Halse, Anne Karine; Schlabach, Martin; Schuster, Jasmin K; Jones, Kevin C; Steinnes, Eiliv; Breivik, Knut

2015-01-01

Soils are major reservoirs for many persistent organic pollutants (POPs). In this study, "newly" regulated POPs i.e. Σendosulfans (α-endosulfan, β-endosulfan, endosulfan sulfate), pentachlorobenzene (PeCB), and short-chain chlorinated paraffins (SCCPs) were determined in background samples from woodland (WL) and grassland (GL) surface soil, collected along an existing latitudinal UK-Norway transect. Statistical analysis, complemented with plots showing the predicted equilibrium distribution and mobility potential, was then explored to discuss factors controlling their spatial distribution. SCCPs were detected with the highest average concentrations (35 ± 100 ng/g soil organic matter (SOM)), followed by Σendosulfans (3 ± 3 ng/g SOM) and PeCB (1 ± 1 ng/g SOM). PeCB and Σendosulfans share many similarities in their distribution in these background soils as well as with several legacy POPs. A steep decline in concentrations of SCCPs with increasing latitude indicates that their occurrence is dictated by proximity to source regions, while concentrations of Σendosulfans peaked in regions experiencing elevated precipitation rates. Copyright © 2014 Elsevier Ltd. All rights reserved.

Penguins significantly increased phosphine formation and phosphorus contribution in maritime Antarctic soils.

PubMed

Zhu, Renbin; Wang, Qing; Ding, Wei; Wang, Can; Hou, Lijun; Ma, Dawei

2014-11-14

Most studies on phosphorus cycle in the natural environment focused on phosphates, with limited data available for the reduced phosphine (PH3). In this paper, matrix-bound phosphine (MBP), gaseous phosphine fluxes and phosphorus fractions in the soils were investigated from a penguin colony, a seal colony and the adjacent animal-lacking tundra and background sites. The MBP levels (mean 200.3 ng kg(-1)) in penguin colony soils were much higher than those in seal colony soils, animal-lacking tundra soils and the background soils. Field PH3 flux observation and laboratory incubation experiments confirmed that penguin colony soils produced much higher PH3 emissions than seal colony soils and animal-lacking tundra soils. Overall high MBP levels and PH3 emissions were modulated by soil biogeochemical processes associated with penguin activities: sufficient supply of the nutrients phosphorus, nitrogen, and organic carbon from penguin guano, high soil bacterial abundance and phosphatase activity. It was proposed that organic or inorganic phosphorus compounds from penguin guano or seal excreta could be reduced to PH3 in the Antarctic soils through the bacterial activity. Our results indicated that penguin activity significantly increased soil phosphine formation and phosphorus contribution, thus played an important role in phosphorus cycle in terrestrial ecosystems of maritime Antarctica.

Penguins significantly increased phosphine formation and phosphorus contribution in maritime Antarctic soils

PubMed Central

Zhu, Renbin; Wang, Qing; Ding, Wei; Wang, Can; Hou, Lijun; Ma, Dawei

2014-01-01

Most studies on phosphorus cycle in the natural environment focused on phosphates, with limited data available for the reduced phosphine (PH3). In this paper, matrix-bound phosphine (MBP), gaseous phosphine fluxes and phosphorus fractions in the soils were investigated from a penguin colony, a seal colony and the adjacent animal-lacking tundra and background sites. The MBP levels (mean 200.3 ng kg−1) in penguin colony soils were much higher than those in seal colony soils, animal-lacking tundra soils and the background soils. Field PH3 flux observation and laboratory incubation experiments confirmed that penguin colony soils produced much higher PH3 emissions than seal colony soils and animal-lacking tundra soils. Overall high MBP levels and PH3 emissions were modulated by soil biogeochemical processes associated with penguin activities: sufficient supply of the nutrients phosphorus, nitrogen, and organic carbon from penguin guano, high soil bacterial abundance and phosphatase activity. It was proposed that organic or inorganic phosphorus compounds from penguin guano or seal excreta could be reduced to PH3 in the Antarctic soils through the bacterial activity. Our results indicated that penguin activity significantly increased soil phosphine formation and phosphorus contribution, thus played an important role in phosphorus cycle in terrestrial ecosystems of maritime Antarctica. PMID:25394572

SH-wave refraction/reflection and site characterization

USGS Publications Warehouse

Wang, Z.; Street, R.L.; Woolery, E.W.; Madin, I.P.

2000-01-01

Traditionally, nonintrusive techniques used to characterize soils have been based on P-wave refraction/reflection methods. However, near-surface unconsolidated soils are oftentimes water-saturated, and when groundwater is present at a site, the velocity of the P-waves is more related to the compressibility of the pore water than to the matrix of the unconsolidated soils. Conversely, SH-waves are directly relatable to the soil matrix. This makes SH-wave refraction/reflection methods effective in site characterizations where groundwater is present. SH-wave methods have been used extensively in site characterization and subsurface imaging for earthquake hazard assessments in the central United States and western Oregon. Comparison of SH-wave investigations with geotechnical investigations shows that SH-wave refraction/reflection techniques are viable and cost-effective for engineering site characterization.

Selenium geochemistry in reclaimed phosphate mine soils and its relationship with plant bioavailability

USDA-ARS?s Scientific Manuscript database

Background and Aims Selenium contamination and accumulation in vegetation have resulted in Se toxicity in livestock and wildlife in reclaimed phosphate mine soils in Southeastern Idaho. Methods Plant and soil samples were collected from five study sites near phosphate mines. Soil physiochemical pr...

Quantification and fragment analysis of soil and cotton root-associated fungal and bacterial populations under different tillage managements

USDA-ARS?s Scientific Manuscript database

Background: Conservation tillage is a common management practice utilized in the hopes of reducing soil erosion and increasing soil carbon. Evidence suggests that conservation tillage may lead to habitat improvement for soil microorganisms, in particular rhizospheric bacteria and arbuscular mycorrhi...

Application of DRIFTS, 13 C NMR, and py-MBMS to Characterize the Effects of Soil Science Oxidation Assays on Soil Organic Matter Composition in a Mollic Xerofluvent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Margenot, Andrew J.; Calderón, Francisco J.; Magrini, Kimberly A.

Chemical oxidations are routinely employed in soil science to study soil organic matter (SOM), and their interpretation could be improved by characterizing oxidation effects on SOM composition with spectroscopy. We investigated the effects of routinely employed oxidants on SOM composition in a Mollic Xerofluvent representative of intensively managed agricultural soils in the California Central Valley. Soil samples were subjected to oxidation by potassium permanganate (KMnO4), sodium hypochlorite (NaOCl), and hydrogen peroxide (H2O2). Additionally, non-oxidized and oxidized soils were treated with hydrofluoric acid (HF) to evaluate reduction of the mineral component to improve spectroscopy of oxidation effects. Oxidized non-HF and HF-treatedmore » soils were characterized by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), 13C cross polarization magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy, and pyrolysis molecular beam mass spectrometry (py-MBMS), and for particle size distribution (PSD) using laser diffractometry (LD). Across the range of soil organic carbon (OC) removed by oxidations (14-72%), aliphatic C-H stretch at 3000-2800 cm-1 (DRIFTS) decreased with OC removal, and this trend was enhanced by HF treatment due to significant demineralization in this soil (70%). Analysis by NMR spectroscopy was feasible only after HF treatment, and did not reveal trends between OC removal and C functional groups. Pyrolysis-MBMS did not detect differences among oxidations, even after HF treatment of soils. Hydrofluoric acid entailed OC loss (13-39%), and for H2O2 oxidized soils increased C:N and substantially decreased mean particle size. This study demonstrates the feasibility of using HF to improve characterizations of SOM composition following oxidations as practiced in soil science, in particular for DRIFTS. Since OC removal by oxidants, mineral removal by HF, and the interaction of oxidants and HF observed for this soil may differ for soils with different mineralogies, future work should examine additional soil and land use types to optimize characterizations of oxidation effects on SOM composition.« less

Mouse Assay for Determination of Arsenic Bioavailability in Contaminated Soils

EPA Science Inventory

Background: Accurate assessment of human exposure estimates from arsenic-contaminated soils depends upon estimating arsenic (As) soil bioavailability. Development of bioavailability assays provides data needed for human health risk assessments and supports development and valida...

Radioactivity measurement of radioactive contaminated soil by using a fiber-optic radiation sensor

NASA Astrophysics Data System (ADS)

Joo, Hanyoung; Kim, Rinah; Moon, Joo Hyun

2016-06-01

A fiber-optic radiation sensor (FORS) was developed to measure the gamma radiation from radioactive contaminated soil. The FORS was fabricated using an inorganic scintillator (Lu,Y)2SiO5:Ce (LYSO:Ce), a mixture of epoxy resin and hardener, aluminum foil, and a plastic optical fiber. Before its real application, the FORS was tested to determine if it performed adequately. The test result showed that the measurements by the FORS adequately followed the theoretically estimated values. Then, the FORS was applied to measure the gamma radiation from radioactive contaminated soil. For comparison, a commercial radiation detector was also applied to measure the same soil samples. The measurement data were analyzed by using a statistical parameter, the critical level to determine if net radioactivity statistically different from background was present in the soil sample. The analysis showed that the soil sample had radioactivity distinguishable from background.

'Natural background' soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

USGS Publications Warehouse

Doerr, S.H.; Woods, S.W.; Martin, D.A.; Casimiro, M.

2009-01-01

Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle (??sl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed (R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimentary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be predicted with confidence from common terrain or soil variables. ?? 2009 Elsevier B.V.

Evaluation and characterization of thyroid-disrupting activities in soil samples along the Second Songhua River, China.

PubMed

Kong, Dongdong; Wang, Yafei; Wang, Jinsheng; Teng, Yanguo; Li, Na; Li, Jian

2016-11-01

In this study, a recombinant thyroid receptor (TR) gene yeast assay combined with Monte Carlo simulation were used to evaluate and characterize soil samples collected from Jilin (China) along the Second Songhua River, for their ant/agonist effect on TR. No TR agonistic activity was found in soils, but many soil samples exhibited TR antagonistic activities, and the bioassay-derived amiodarone hydrochloride equivalents, which was calculated based on Monte Carlo simulation, ranged from not detected (N.D.) to 35.5μg/g. Hydrophilic substance fractions were determined to be the contributors to TR antagonistic activity in these soil samples. Our results indicate that the novel calculation method is effective for the quantification and characterization of TR antagonists in soil samples, and these data could provide useful information for future management and remediation efforts for contaminated soils. Copyright © 2016 Elsevier Inc. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This report was prepared at the request of the Lawrence Livermore Laboratory (LLL) to provide background information for analyzing soil-structure interaction by the frequency-independent impedance function approach. LLL is conducting such analyses as part of its seismic review of selected operating plants under the Systematic Evaluation Program for the US Nuclear Regulatory Commission. The analytical background and basic assumptionsof the impedance function theory are briefly reviewed, and the role of radiation damping in soil-structure interaction analysis is discussed. The validity of modeling soil-structure interaction by using frequency-independent functions is evaluated based on data from several field tests. Finally, the recommendedmore » procedures for performing soil-structure interaction analyses are discussed with emphasis on the modal superposition method.« less

Evaluating the crop coefficient using spectral reflectance

USGS Publications Warehouse

Heilman, J. L.; Heilman, W. E.; Moore, Donald G.

1982-01-01

Significant linear relationships were found between PVI and percent cover (r2 = 0.911), and between Kc and percent cover (r2 = 0.815). In addition, the position of the PVl intersection on the soil background line changed as a result of soil moisture increases following irrigation, even at high percent cover. Thus, once experimental relationships between Kc and crop growth are established, a mean Kc can be determined from spectral estimates of stage of development and the soil background component of PVI can be used to adjust the mean K, for increased evaporation following irrigation because the ratio of actual to potential evapotranspiration will approach 1 when the soil surface is wet.

Ground beetles in Mediterranean olive agroecosystems: Their significance and functional role as bioindicators (Coleoptera, Carabidae)

PubMed Central

Mazzei, Antonio; Bonacci, Teresa; Scalercio, Stefano; Iannotta, Nino; Brandmayr, Pietro

2018-01-01

The impact of agricultural practices and soil management on the communities of arthropods living in the agricultural landscape is acknowledged as a critical issue by the literature, and it needs to be better investigated to improve the ecological sustainability of agriculture. In the present study, we aimed to study how soil management affect carabid species distribution in one of the most typical agroecosystem of the Mediterranean region, i.e. the olive grove. In South Italy olive plantations feature different types of soil management, from tillage to half- or full-cover cropping. Species distribution has been examined for a total of 10,189 individuals and 62 species collected from 17 sites. Notably from our analysis we have observed that three factors (climax vegetation, soil features and soil management) explained half of the data variability. The composition of species groupings mirrors both bioclimatic conditions (climax vegetation) and soil features, especially watering, while soil management affects the species distribution, with different intensity from site to site. Eleven species have been recognized as the most abundant in the different facets of the studied olive groves and consequently designated as characteristics of the olive agroecosystem. The species traits of the sampled species have been weighted for a compelling evaluation of the effects of agricultural management on biodiversity, showing uniform traits distribution when coping with the ecological factors that characterize the different plantation facets. We have found that carabid beetles can be used as model organisms for studying the effects of agricultural practices. Our study suggests that the interaction of man-induced trasformation with the natural background of the olive agroecosystem may be difficult to disentangle, so that such complexity must be taken into account when carabid beetles are expected to provide an ecosystem service for good agricultural practices. PMID:29558493

Characterization of soil nematode communities in three cropping systems through morphological and DNA metabarcoding approaches

USDA-ARS?s Scientific Manuscript database

Communities of soil nematodes impact ecosystem functions, including plant growth, decomposition, and nutrient cycling, all of which are vital processes in agriculture. We used complementary morphological and DNA metabarcoding analyses to characterize soil nematode communities in three cropping syste...

Relative Bioavailability and Bioaccessability and Speciation of Arsenic in Contaminated Soils

EPA Science Inventory

Background: Assessment of soil arsenic (As) bioavailability may profoundly affect the extent of remediation required at contaminated sites by improving human exposure estimates. Because small adjustments in soil As bioavailability estimates can significantly alter risk assessment...

The Potential Use of Polarized Reflected Light in the Remote Sensing of Soil Moisture

DTIC Science & Technology

to 89% for saturated soil, indicating that the polarization method may be viable as a remote sensing system for determining soil moistures. Background on the methods and implications of the results are presented.

Enrichment and exposure assessment of As, Cr and Pb of the soils in the vicinity of Stawell, Victoria, Australia.

PubMed

Noble, Ryan R P; Hough, Robert M; Watkins, Ronald T

2010-06-01

Stawell Gold Mine in NW Victoria, Australia, mines ores that contain large concentrations of As and significant quantities of the metals Pb and Cr. The aim of this research was to understand the dispersion, enrichment and probable exposure of these potentially hazardous elements around the mine site. Fifty-five surface soil samples were collected near the mine (<15 km) and analysed by ICP-MS/OES following bioavailable and four-acid extractions. Soils near the mine show greater concentrations of As, Cr and Pb than those near a regionally determined background. This is attributed to the combination of a natural geochemical halo around mineralization and anthropogenic dispersion due to mining and urbanization. Total As concentrations were between 16 and 946 mg kg(-1) near the mine in a regional background of 1-16 mg kg(-1). Total Cr concentrations were between 18 and 740 mg kg(-1) near the mine in a regional background of 26-143 mg kg(-1). Total Pb concentrations were between 12 and 430 mg kg(-1) near the mine in a regional background of 9-23 mg kg(-1). Dispersion of contaminant elements from the present ore processing is <500 m. The most enriched soils occur close to the town and are unrelated to present mining practices. The bioavailable As, Cr and Pb, soil ingestion rates and Risk Reference Doses were used to estimate health risks. An average toddler (12 kg) would need to consume at least 1.5 g, and most likely 12 g, of soil per day to show some symptoms of As toxicity. The maximum measured bioavailable As would pose a risk at average ingestion rates of 200 mg per day. Individuals with soil-eating disorders would exceed the safe daily consumption limits for As, and potentially Cr and Pb. Small children are not typically exposed to soil everyday, very few have soil eating disorders, and, therefore, the health risk from the soils around the mine is minimal.

[Study on pollution evaluation of heavy metal in surface soil of the original site of Qingdao North Station].

PubMed

Zhu, Lei; Jia, Yong-gang; Pan, Yu-ying

2013-09-01

The determination of pollution extent and health risk assessment are the premise of heavy metal contaminated site remediation. The content of Cu, Cr, Pb, Cd, Zn, Ni in Qingdao North Station was detected, and the correlation of the 6 kinds of heavy metal content was analyzed. The pollution extent in excess of background values was characterized by anthropogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geoaccumulation index and a new method which connects geoaccumulation index with Nemero index. Finally, human health risk assessment was carried out with health risk assessment model for heavy metal content. The results showed that Qingdao North Station soil were polluted by heavy metals. Six heavy metal pollution levels were: Cd > Cu > Ni > Pb > Cr > Zn, and Cd had reached the severity pollution level, Cu and Ni followed by, Cr, Pb and Zn were in minor pollution level. The order of coefficient variation in all heavy metals was: Cd > Ni > Cr > Zn > Pb > Cu. Within the study area soil heavy metal distribution was different, but overall discrepancy was small. The order of non-cancer hazards of heavy metals in soil was Cr > Pb > Cu > Ni > Cd > Zn, and the order of carcinogen risks of heavy metals was Ni > Cd. The non-cancer hazard and carcinogen risks values of metals were both lower than that their threshold values. They were not the direct threats to human health.

Soil, Groundwater, Surface Water, and Sediments of Kennedy Space Center, Florida: Background Chemical and Physical Characteristics

NASA Technical Reports Server (NTRS)

Shmalzer, Paul A.; Hensley, Melissa A.; Mota, Mario; Hall, Carlton R.; Dunlevy, Colleen A.

2000-01-01

This study documented background chemical composition of soils, groundwater, surface; water, and sediments of Kennedy Space Center. Two hundred soil samples were collected, 20 each in 10 soil classes. Fifty-one groundwater wells were installed in 4 subaquifers of the Surficial Aquifer and sampled; there were 24 shallow, 16 intermediate, and 11 deep wells. Forty surface water and sediment samples were collected in major watershed basins. All samples were away from sites of known contamination. Samples were analyzed for organochlorine pesticides, aroclors, chlorinated herbicides, polycyclic aromatic hydrocarbons (PAH), total metals, and other parameters. All aroclors (6) were below detection in all media. Some organochlorine pesticides were detected at very low frequencies in soil, sediment, and surface water. Chlorinated herbicides were detected at very low frequencies in soil and sediments. PAH occurred in low frequencies in soiL, shallow groundwater, surface water, and sediments. Concentrations of some metals differed among soil classes, with subaquifers and depths, and among watershed basins for surface water but not sediments. Most of the variation in metal concentrations was natural, but agriculture had increased Cr, Cu, Mn, and Zn.

Characterization of soil spatial variability for site-specific management using soil electrical conductivity and other remotely sensed data

NASA Astrophysics Data System (ADS)

Bang, Jisu

Field-scale characterization of soil spatial variability using remote sensing technology has potential for achieving the successful implementation of site-specific management (SSM). The objectives of this study were to: (i) examine the spatial relationships between apparent soil electrical conductivity (EC a) and soil chemical and physical properties to determine if EC a could be useful to characterize soil properties related to crop productivity in the Coastal Plain and Piedmont of North Carolina; (ii) evaluate the effects of in-situ soil moisture variation on ECa mapping as a basis for characterization of soil spatial variability and as a data layer in cluster analysis as a means of delineating sampling zones; (iii) evaluate clustering approaches using different variable sets for management zone delineation to characterize spatial variability in soil nutrient levels and crop yields. Studies were conducted in two fields in the Piedmont and three fields in the Coastal Plain of North Carolina. Spatial measurements of ECa via electromagnetic induction (EMI) were compared with soil chemical parameters (extractable P, K, and micronutrients; pH, cation exchange capacity [CEC], humic matter or soil organic matter; and physical parameters (percentage sand, silt, and clay; and plant-available water [PAW] content; bulk density; cone index; saturated hydraulic conductivity [Ksat] in one of the coastal plain fields) using correlation analysis across fields. We also collected ECa measurements in one coastal plain field on four days with significantly different naturally occurring soil moisture conditions measured in five increments to 0.75 m using profiling time-domain reflectometry probes to evaluate the temporal variability of ECa associated with changes in in-situ soil moisture content. Nonhierarchical k-means cluster analysis using sensor-based field attributes including vertical ECa, near-infrared (NIR) radiance of bare-soil from an aerial color infrared (CIR) image, elevation, slope, and their combinations was performed to delineate management zones. The strengths and signs of the correlations between ECa and measured soil properties varied among fields. Few strong direct correlations were found between ECa and the soil chemical and physical properties studied (r2 < 0.50), but correlations improved considerably when zone mean ECa and zone means of selected soil properties among ECa zones were compared. The results suggested that field-scale ECa survey is not able to directly predict soil nutrient levels at any specific location, but could delimit distinct zones of soil condition among which soil nutrient levels differ, providing an effective basis for soil sampling on a zone basis. (Abstract shortened by UMI.)

Application of principal component analysis in the pollution assessment with heavy metals of vegetable food chain in the old mining areas

PubMed Central

2012-01-01

Background The aim of the paper is to assess by the principal components analysis (PCA) the heavy metal contamination of soil and vegetables widely used as food for people who live in areas contaminated by heavy metals (HMs) due to long-lasting mining activities. This chemometric technique allowed us to select the best model for determining the risk of HMs on the food chain as well as on people's health. Results Many PCA models were computed with different variables: heavy metals contents and some agro-chemical parameters which characterize the soil samples from contaminated and uncontaminated areas, HMs contents of different types of vegetables grown and consumed in these areas, and the complex parameter target hazard quotients (THQ). Results were discussed in terms of principal component analysis. Conclusion There were two major benefits in processing the data PCA: firstly, it helped in optimizing the number and type of data that are best in rendering the HMs contamination of the soil and vegetables. Secondly, it was valuable for selecting the vegetable species which present the highest/minimum risk of a negative impact on the food chain and human health. PMID:23234365

Dynamics of water mass in the Central Siberia permafrost zone based on gravity survey from the grace satellites

NASA Astrophysics Data System (ADS)

Im, S. T.; Kharuk, V. I.

2015-12-01

The GRACE gravimetric survey is applied to analyze the equivalent water mass anomalies (EWMAs) in the permafrost zone of Central Siberia. Variations in EWMAs are related to precipitation, air temperature, potential evapotranspiration, and soil composition (drainage conditions). The EWMA dynamics demonstrates two periods. The period of 2003-2008 is characterized by a positive trend. The one of 2008-2012 shows a decrease in the trend with a simultaneous increase by 30-70% of EWMA dispersion in the background of growth (up to 40%) of precipitation variability. The rate of water mass increment demonstrates a positive correlation with the sand and gravel contents in soil ( r = 0.72) and a negative one with clay content ( r =-0.69 to-0.77). For Taimyr Peninsula, there is a deficit of residual water mass (~250 mm for the period of 2012-2013) indicating the deeper thawing of permafrost soils. In the Central Siberian Plateau, the indicator of more intensive permafrost thawing (and that of an increase in active layer thickness) is a considerable trend of water mass increase (2003-2008). The increasing trend of the largest Siberian rivers (Yenisei and Lena) is revealed in the period of 2003-2012.

Identification of Heavy Metal Pollution Derived From Traffic in Roadside Soil Using Magnetic Susceptibility.

PubMed

Yang, Pingguo; Ge, Jing; Yang, Miao

2017-06-01

The study integrates surface and vertical distribution of magnetic susceptibility and heavy metal contents (Pb, Cu, Zn and Fe) to characterize the signature of vehicle pollutants in roadside soils at Linfen city, China. Sites with reforestation and without vegetation cover were investigated. The results showed that magnetic susceptibility and heavy metal contents were higher at the roadside without trees than in the reforest belt. The variations of magnetic susceptibility and heavy metal contents decreased both with distance and with depth. The maximum value was observed at 5-10 m away from the roadside edge. The vertical distribution in soil revealed accumulation of pollutants in 0-5 cm topsoils. The average contents were higher than the background values and in the order Fe (107.21 g kg -1 ), Zn (99.72 mg kg -1 ), Pb (90.99 mg kg -1 ), Cu (36.14 mg kg -1 ). Coarse multi domain grains were identified as the dominating magnetic particles. Multivariate statistical and SEM/EDX analyses suggested that the heavy metals derived from traffic sources. Trees act as efficient receptors and green barrier, which can reduce vehicle derived pollution.

Characteristic variations in reflectance of surface soils

NASA Technical Reports Server (NTRS)

Stoner, E. R.; Baumgardner, M. F. (Principal Investigator)

1982-01-01

Surface soil samples from a wide range of naturally occurring soils were obtained for the purpose of studying the characteristic variations in soil reflectance as these variations relate to other soil properties and soil classification. A total 485 soil samples from the U.S. and Brazil representing 30 suborders of the 10 orders of 'Soil Taxonomy' was examined. The spectral bidirectional reflectance factor was measured on uniformly moist soils over the 0.52 to 2.32 micron wavelength range with a spectroradiometer adapted for indoor use. Five distinct soil spectral reflectance curve forms were identified according to curve shape, the presence or absence of absorption bands, and the predominance of soil organic matter and iron oxide composition. These curve forms were further characterized according to generically homogeneous soil properties in a manner similar to the subdivisions at the suborder level of 'Soil Taxonomy'. Results indicate that spectroradiometric measurements of soil spectral bidirectional reflectance factor can be used to characterize soil reflectance in terms that are meaningful to soil classification, genesis, and survey.

Distribution, source identification and health risk assessment of soil heavy metals in urban areas of Isfahan province, Iran

NASA Astrophysics Data System (ADS)

Rastegari Mehr, Meisam; Keshavarzi, Behnam; Moore, Farid; Sharifi, Reza; Lahijanzadeh, Ahmadreza; Kermani, Maryam

2017-08-01

The present study examines some heavy metals (As, Cd, Co, Cr, Cu, Ni, Pb and Zn) contents in urban soils of 23 cities in Isfahan province, central Iran. For this purpose, 83 topsoil samples were collected and analyzed by ICP-MS. Results showed that the concentrations of As, Cd, Cu, Pb and Zn are higher than background values, while Co, Cr and Ni concentrations are close to the background. Compared with heavy metal concentrations in selected cities around the world, As, Cd, Cu, Pb and Zn concentrations in urban soils of Isfahan are relatively enriched. Moreover, natural background concentrations of Co, Cr and Ni in Isfahan province soil are high and the apparent enrichment relative to other major cities of the world is due to this high background contents. Calculated contamination factor (CF) confirmed that As, Cd, Cu, Pb and Zn are extremely enriched in the urban soils. Furthermore, pollution load index (PLI) and Geoaccumulation index (Igeo) highlighted that highly contaminated cities are mostly affected by pollution from traffic, industries and Shahkuh Pb-Zn mine. Based on hazard quotients (HQ), hazard index (HI) and cancer risk (CR) calculated in this study, human health risk (particularly for Pb and Cd) have reached alarming scales. Results from principle component analysis (PCA) and positive matrix factorization (PMF) introduces three sources for soils heavy metals including mine and industries (mainly for Pb, Zn, Cd and As); urban activities (particularly for Cu, Pb and Zn); and geogenic source (Ni, Co and Cr).

Effects of long-term soil and crop management on soil hydraulic properties for claypan soils

USDA-ARS?s Scientific Manuscript database

Regional and national soil maps have been developed along with associated soil property databases to assist users in making land management decisions based on soil characteristics. These soil properties include average values from soil characterization for each soil series. In reality, these propert...

Field scale manure born animal waste management : GIS application

USDA-ARS?s Scientific Manuscript database

Intensive beef backgrounding often accumulate manure born soil nutrients, microbes, and pharmaceuticals at different site locations. Unless properly managed, such waste materials can pollute surrounding soil and water sources. Soil sampling from these sites helps determining waste material levels bu...

Distributed Soil Moisture Estimation in a Mountainous Semiarid Basin: Constraining Soil Parameter Uncertainty through Field Studies

NASA Astrophysics Data System (ADS)

Yatheendradas, S.; Vivoni, E.

2007-12-01

A common practice in distributed hydrological modeling is to assign soil hydraulic properties based on coarse textural datasets. For semiarid regions with poor soil information, the performance of a model can be severely constrained due to the high model sensitivity to near-surface soil characteristics. Neglecting the uncertainty in soil hydraulic properties, their spatial variation and their naturally-occurring horizonation can potentially affect the modeled hydrological response. In this study, we investigate such effects using the TIN-based Real-time Integrated Basin Simulator (tRIBS) applied to the mid-sized (100 km2) Sierra Los Locos watershed in northern Sonora, Mexico. The Sierra Los Locos basin is characterized by complex mountainous terrain leading to topographic organization of soil characteristics and ecosystem distributions. We focus on simulations during the 2004 North American Monsoon Experiment (NAME) when intensive soil moisture measurements and aircraft- based soil moisture retrievals are available in the basin. Our experiments focus on soil moisture comparisons at the point, topographic transect and basin scales using a range of different soil characterizations. We compare the distributed soil moisture estimates obtained using (1) a deterministic simulation based on soil texture from coarse soil maps, (2) a set of ensemble simulations that capture soil parameter uncertainty and their spatial distribution, and (3) a set of simulations that conditions the ensemble on recent soil profile measurements. Uncertainties considered in near-surface soil characterization provide insights into their influence on the modeled uncertainty, into the value of soil profile observations, and into effective use of on-going field observations for constraining the soil moisture response uncertainty.

Scientific background for soil monitoring on National Forests and Rangelands: workshop proceedings; April 29-30, 2008; Denver, CO

Treesearch

Deborah Page-Dumroese; Daniel Neary; Carl Trettin

2010-01-01

This workshop was developed to determine the state-of-the-science for soil monitoring on National Forests and Rangelands. We asked international experts in the field of soil monitoring, soil monitoring indicators, and basic forest soil properties to describe the limits of our knowledge and the ongoing studies that are providing new information. This workshop and the...

Technogenesis and the main levels of soil ecosystems' transformation in oil production areas

NASA Astrophysics Data System (ADS)

Buzmakov, Sergey

2017-04-01

The obtained experimental data, the results of field studies and the analysis of references make it possible to describe peculiarities of technogenic transformation of ecosystems. Experimental data allow to determine the main levels of oil pollution on the basis of changes in biotope properties and reaction of a biota. Background level. Pollution is absent. Biotope corresponds to natural zonal sequence. The content of oil products is up to 0,11 g/kg. First level: the dose of pollution is 0,8-1g of oil on 1 kg of soil. Conditions for plants' growth are optimum. Initially plants gain gross weight, and then lose it to the background level. The number of saprotrophes and oil oxidizing microorganisms rises. Second level: the pollution dose is up to 15 g per 1 kg of soil. The capillary moisture capacity increases reaching the maximum. The number of saprophytes and oil oxidizing microorganisms rises. Third level: the pollution dose is 15-21g per 1 kg of soil. Capillary capacity of soils decreases to background level. Time of filtration and absorption of moisture is increased. Fourth level: the pollution dose is 21-32g per 1 kg of soil. Anaerobic and hydrophobic conditions develop. The number of saprophytes and oil oxidizing microorganisms rises. Fifth level: the dose of pollution is 32 - 50g per 1 kg of soil. Formation of 3,4 benzpyrene increases sharply. The number of saprophytes and oil oxidizing microorganisms is at maximum level. Sixth level: the dose of pollution is 50 - 91g per 1 kg of soil. Formation of 3,4 benzpyrene is dangerous for biota. Time of absorption and filtration of water through the soil reaches its maximum. The number of saprophytes and oil oxidizing microorganisms decreases, but remains higher than at background level. Seventh level: the pollution dose is 91-150g per 1 kg of soil. The number of saprophytes and oil oxidizing microorganisms decreases to background level. Eighth level: the pollution dose is of 150-300 g per 1 kg of soil. The substratum becomes toxic. The number of saprophytes and oil oxidizing microorganisms is lower than at background level. Ninth level: the dose of pollution is 300 g per 1 kg of soil and above. Substratum is abiogenic. Field researches show that the influence of oil fields is manifested in the form of intake of emergency oil and emergency salty waters as well as ground water runoff and surface water containing salts and oil products from platforms of oil sites into surrounding land ecosystems, along with their atmospheric pollution. Degradation and recovery process is manifested in formation of a natural- technogenic ecosystem with azonal biotopes. Around powerful sources of pollution there should be created the manageable natural and technogenic ecosystems facilitating self-restoration of the environment. It is necessary to create a system of accumulating and transit ecosystems which would make it possible to carry out the degradation and dispersion of accumulated pollutants. Implementation of our proposals will result in stabilization of ecological situation.

Of the necessity of knowledge of the natural pedo-geochemical background content in the evaluation of the contamination of soils by trace elements.

PubMed

Baize, D; Sterckeman, T

2001-01-08

In order to evaluate the contamination of the Dornach (Switzerland) site within the framework of the CEEM-Soil project, each participating team was allowed to take a maximum of 15 samples. The French team's sampling was organized in such a way as to answer the following questions: (i) what is the natural concentration of the soils at this site (local pedo-geochemical background content)?; (ii) what are the levels of Cd, Cu, Pb and Zn contamination of the soil?; (iii) what is the depth reached by the surface contamination that is derived from atmospheric fallout?; (iv) how is the contamination spread along the longest axis of the area under study? The relationships between total Fe and the trace metals have allowed local variations in the natural pedo-geochemical background content to be detected and thus permitted the anthropogenic contamination to be estimated. There would appear to be a low level of Pb contamination over all the site investigated (an increase of the order of 5-10 mg kg(-1) on the background level), limited to the surface humus-bearing layers. There is also a significant contamination by Cu over all of the site (an increase of the order of 30-40 mg kg(-1)). This contamination has remained in the surface horizons (0-20 cm). Very high Zn and Cd concentrations have been found in the four surface (0-4 cm) and deep horizons (15-70 cm) taken under the forest and very much lower values in the samples taken from cultivated soils. The most likely explanation is an unequal inheritance between the upper part of the site (wooded with thinner very clayey soils) and the lower cultivated part of the site (with thicker less clayey soils developed in a loamy material). For various reasons, it seems unlikely that a contamination of the wooded part should be so much higher than the cultivated part due to the interception of atmospheric dust by the trees. The local pedo-geochemical background Cd and Zn content of the upper wooded part proved to be clearly higher than that which would be encountered in most soils of Switzerland and France. Given this evaluation of the background content, it seems that only the surface horizons have been affected by Zn contamination (an addition of approx. 60-100 mg kg(-1)). In the case of Cd, the increase in concentrations is only 0.5-1 mg kg(-1) for the ploughed horizons, as well as the for the A horizons.

Effects of Long-term Soil and Crop Management on Soil Hydraulic Properties for Claypan Soils

USDA-ARS?s Scientific Manuscript database

Regional and national soil maps and associated databases of soil properties have been developed to help land managers make decisions based on soil characteristics. Hydrologic modelers also utilize soil hydraulic properties provided in these databases, in which soil characterization is based on avera...

Imaging and Analytical Approaches for Characterization of Soil Mineral Weathering

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dohnalkova, Alice; Arey, Bruce; Varga, Tamas

Soil minerals weathering is the primary natural source of nutrients necessary to sustain productivity in terrestrial ecosystems. Soil microbial communities increase soil mineral weathering and mineral-derived nutrient availability through physical and chemical processes. Rhizosphere, the zone immediately surrounding plant roots, is a biogeochemical hotspot with microbial activity, soil organic matter production, mineral weathering, and secondary phase formation all happening in a small temporally ephemeral zone of steep geochemical gradients. The detailed exploration of the micro-scale rhizosphere is essential to our better understanding of large-scale processes in soils, such as nutrient cycling, transport and fate of soil components, microbial-mineral interactions, soilmore » erosion, soil organic matter turnover and its molecular-level characterization, and predictive modeling.« less

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR SOIL CHARACTERIZATION (UA-L-11.1)

EPA Science Inventory

The purpose of this SOP is to describe the procedures to be followed in splitting and determining the grain size characteristics, electrical conductivity, and pH of the "Composite Soil" and "Foundation Soil" samples. This procedure applies to the general characterization of sedi...

Bacterial communities in commercial aircraft high-efficiency particulate air (HEPA) filters assessed by PhyloChip analysis.

PubMed

Korves, T M; Piceno, Y M; Tom, L M; Desantis, T Z; Jones, B W; Andersen, G L; Hwang, G M

2013-02-01

Air travel can rapidly transport infectious diseases globally. To facilitate the design of biosensors for infectious organisms in commercial aircraft, we characterized bacterial diversity in aircraft air. Samples from 61 aircraft high-efficiency particulate air (HEPA) filters were analyzed with a custom microarray of 16S rRNA gene sequences (PhyloChip), representing bacterial lineages. A total of 606 subfamilies from 41 phyla were detected. The most abundant bacterial subfamilies included bacteria associated with humans, especially skin, gastrointestinal and respiratory tracts, and with water and soil habitats. Operational taxonomic units that contain important human pathogens as well as their close, more benign relatives were detected. When compared to 43 samples of urban outdoor air, aircraft samples differed in composition, with higher relative abundance of Firmicutes and Gammaproteobacteria lineages in aircraft samples, and higher relative abundance of Actinobacteria and Betaproteobacteria lineages in outdoor air samples. In addition, aircraft and outdoor air samples differed in the incidence of taxa containing human pathogens. Overall, these results demonstrate that HEPA filter samples can be used to deeply characterize bacterial diversity in aircraft air and suggest that the presence of close relatives of certain pathogens must be taken into account in probe design for aircraft biosensors. A biosensor that could be deployed in commercial aircraft would be required to function at an extremely low false alarm rate, making an understanding of microbial background important. This study reveals a diverse bacterial background present on aircraft, including bacteria closely related to pathogens of public health concern. Furthermore, this aircraft background is different from outdoor air, suggesting different probes may be needed to detect airborne contaminants to achieve minimal false alarm rates. This study also indicates that aircraft HEPA filters could be used with other molecular techniques to further characterize background bacteria and in investigations in the wake of a disease outbreak. © 2012 John Wiley & Sons A/S.

Mapping Spatial Variability of Soil Salinity in a Coastal Paddy Field Based on Electromagnetic Sensors

PubMed Central

Guo, Yan; Huang, Jingyi; Shi, Zhou; Li, Hongyi

2015-01-01

In coastal China, there is an urgent need to increase land area for agricultural production and urban development, where there is a rapid growing population. One solution is land reclamation from coastal tidelands, but soil salinization is problematic. As such, it is very important to characterize and map the within-field variability of soil salinity in space and time. Conventional methods are often time-consuming, expensive, labor-intensive, and unpractical. Fortunately, proximal sensing has become an important technology in characterizing within-field spatial variability. In this study, we employed the EM38 to study spatial variability of soil salinity in a coastal paddy field. Significant correlation relationship between ECa and EC1:5 (i.e. r >0.9) allowed us to use EM38 data to characterize the spatial variability of soil salinity. Geostatistical methods were used to determine the horizontal spatio-temporal variability of soil salinity over three consecutive years. The study found that the distribution of salinity was heterogeneous and the leaching of salts was more significant in the edges of the study field. By inverting the EM38 data using a Quasi-3D inversion algorithm, the vertical spatio-temporal variability of soil salinity was determined and the leaching of salts over time was easily identified. The methodology of this study can be used as guidance for researchers interested in understanding soil salinity development as well as land managers aiming for effective soil salinity monitoring and management practices. In order to better characterize the variations in soil salinity to a deeper soil profile, the deeper mode of EM38 (i.e., EM38v) as well as other EMI instruments (e.g. DUALEM-421) can be incorporated to conduct Quasi-3D inversions for deeper soil profiles. PMID:26020969

Nickel, Cobalt, Chromium and Copper in agricultural and grazing land soils of Europe

NASA Astrophysics Data System (ADS)

Albanese, Stefano; Sadeghi, Martiya; De Vivo, Benedetto; Lima, Annamaria; Cicchella, Domenico; Dinelli, Enrico

2014-05-01

In the framework of the GEMAS (Geochemical Mapping of Agricultural and Grazing Land Soils) project, concentrations of Ni, Co, Cu and Cr were determined for the whole available dataset (2218 samples of agricultural soil and 2127 samples of grazing land soil) covering a total area of 5.6 million sq km all over Europe. The distribution pattern of Ni in the European soils (both agricultural and grazing land soils) shows the highest concentrations in correspondence with the Mediterranean area (especially in Greece, the Balcan Peninsula and NW Italy) with average values generally ranging between 40 mg/kg and 140 mg/kg and anomalous areas characterized by peaks higher than 2400 mg/kg. Concentrations between 10 mg/kg and 40 mg/kg characterize Continental Europe north of Alps and, partly, the Scandinavian countries. Lower concentrations (< 10 mg/kg) occurs near the Trans-European Suture Zone, one of the main tectonic borders in Europe, and they are limited on the south by the maximum extent limit of the last glaciation. Cobalt and Cr show distribution patterns similar to Ni in both agricultural and grazing land soils. The maximum concentration peaks of Cobalt and Cr rise up to respectively 126 mg/kg and 696 mg/kg in agricultural soils and up to 255 mg/kg and 577 mg/kg in grazing land soils. Copper distribution in the soils collected across Europe, although has a general correspondence with the patterns of Ni, Co, Cr, shows some peculiarities. Specifically, Cu is characterized by high concentration values (up to 395 mg/kg in agricultural soils and 373 mg/kg in Grazing land soils) also in correspondence with the Roman Comagmatic Province and the south western coast of France characterized by a wide spread of vineyards.

Mapping spatial variability of soil salinity in a coastal paddy field based on electromagnetic sensors.

PubMed

Guo, Yan; Huang, Jingyi; Shi, Zhou; Li, Hongyi

2015-01-01

In coastal China, there is an urgent need to increase land area for agricultural production and urban development, where there is a rapid growing population. One solution is land reclamation from coastal tidelands, but soil salinization is problematic. As such, it is very important to characterize and map the within-field variability of soil salinity in space and time. Conventional methods are often time-consuming, expensive, labor-intensive, and unpractical. Fortunately, proximal sensing has become an important technology in characterizing within-field spatial variability. In this study, we employed the EM38 to study spatial variability of soil salinity in a coastal paddy field. Significant correlation relationship between ECa and EC1:5 (i.e. r >0.9) allowed us to use EM38 data to characterize the spatial variability of soil salinity. Geostatistical methods were used to determine the horizontal spatio-temporal variability of soil salinity over three consecutive years. The study found that the distribution of salinity was heterogeneous and the leaching of salts was more significant in the edges of the study field. By inverting the EM38 data using a Quasi-3D inversion algorithm, the vertical spatio-temporal variability of soil salinity was determined and the leaching of salts over time was easily identified. The methodology of this study can be used as guidance for researchers interested in understanding soil salinity development as well as land managers aiming for effective soil salinity monitoring and management practices. In order to better characterize the variations in soil salinity to a deeper soil profile, the deeper mode of EM38 (i.e., EM38v) as well as other EMI instruments (e.g. DUALEM-421) can be incorporated to conduct Quasi-3D inversions for deeper soil profiles.

The Impacts of Heating Strategy on Soil Moisture Estimation Using Actively Heated Fiber Optics.

PubMed

Dong, Jianzhi; Agliata, Rosa; Steele-Dunne, Susan; Hoes, Olivier; Bogaard, Thom; Greco, Roberto; van de Giesen, Nick

2017-09-13

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature ( T cum ), the maximum temperature ( T max ), or the soil thermal conductivity determined from the cooling phase after heating ( λ ). This study investigates the performance of the T cum , T max and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the T cum and T max methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of T cum to soil moisture. Hence, the T cum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error.

The Impacts of Heating Strategy on Soil Moisture Estimation Using Actively Heated Fiber Optics

PubMed Central

Dong, Jianzhi; Agliata, Rosa; Steele-Dunne, Susan; Hoes, Olivier; Bogaard, Thom; Greco, Roberto; van de Giesen, Nick

2017-01-01

Several recent studies have highlighted the potential of Actively Heated Fiber Optics (AHFO) for high resolution soil moisture mapping. In AHFO, the soil moisture can be calculated from the cumulative temperature (Tcum), the maximum temperature (Tmax), or the soil thermal conductivity determined from the cooling phase after heating (λ). This study investigates the performance of the Tcum, Tmax and λ methods for different heating strategies, i.e., differences in the duration and input power of the applied heat pulse. The aim is to compare the three approaches and to determine which is best suited to field applications where the power supply is limited. Results show that increasing the input power of the heat pulses makes it easier to differentiate between dry and wet soil conditions, which leads to an improved accuracy. Results suggest that if the power supply is limited, the heating strength is insufficient for the λ method to yield accurate estimates. Generally, the Tcum and Tmax methods have similar accuracy. If the input power is limited, increasing the heat pulse duration can improve the accuracy of the AHFO method for both of these techniques. In particular, extending the heating duration can significantly increase the sensitivity of Tcum to soil moisture. Hence, the Tcum method is recommended when the input power is limited. Finally, results also show that up to 50% of the cable temperature change during the heat pulse can be attributed to soil background temperature, i.e., soil temperature changed by the net solar radiation. A method is proposed to correct this background temperature change. Without correction, soil moisture information can be completely masked by the background temperature error. PMID:28902141

Characterization of soils containing adipocere.

PubMed

Fiedler, S; Schneckenberger, K; Graw, M

2004-11-01

The formation of adipocere (commonly known as grave wax), a spontaneous inhibition of postmortem changes, has been extensively analyzed in forensic science. However, soils in which adipocere formation occurs have never been described in detail. Therefore, this study is intended as a first step in the characterization of soils containing adipocere. Two grave soils (Gleyic Anthrosols) that prevent the timely reuse of graves due to the occurrence of adipocere and a control soil (Gleyic Luvisol) were selected from a cemetery in the Central Black Forest (Southwest Germany). Descriptions of soil morphology and a wide assay of physical, chemical, and microbiologic soil characteristics were accomplished. In contrast to the control soil, the grave soils were characterized by lower bulk density and pH. The degradation of the soil structure caused by digging led to a higher water table and the expansion of the reducing conditions in the graves where the prevalent absence of oxygen in range of the coffins inhibited decomposition processes. Although the formation of adipocere led to the conservation of the buried corpses, phosphorus, dissolved organic carbon, and cadavarine leaching from the graves was observed. Microbial biomass and microbial activity were higher in the control soil and hence reflected the inert character of adipocere. The study results clearly show the need for additional approaches in forensic, pedologic, and microbiologic research.

3D soil structure characterization of Biological Soil Crusts from Alpine Tarfala Valley

NASA Astrophysics Data System (ADS)

Mele, Giacomo; Gargiulo, Laura; Zucconi, Laura; D'Acqui, Luigi; Ventura, Stefano

2017-04-01

Cyanobacteria filaments, microfungal hyphae, lichen rhizinae and anchoring rhizoids of bryophytes all together contribute to induce formation of structure in the thin soil layer beneath the Biological Soil Crusts (BSCs). Quantitative assessment of the soil structure beneath the BSCs is primarily hindered by the fragile nature of the crusts. Therefore, the role of BSCs in affecting such soil physical property has been rarely addressed using direct measurements. In this work we applied non-destructive X-ray microtomography imaging on five different samples of BSCs collected in the Alpine Tarfala Valley (northern Sweden), which have already been characterized in terms of fungal biodiversity in a previous work. We obtained images of the 3D spatial organization of the soil underneath the BSCs and characterized its structure by applying procedures of image analysis allowing to determine pore size distribution, pore connectivity and aggregate size distribution. Results has then been correlated with the different fungal assemblages of the samples.

Characterization of Air Emissions from Open Burning and Open Detonation of Gun Propellants and Ammunition

DTIC Science & Technology

2016-11-07

To) 4. TITLE AND SUBTITLE Innovative Technology Development for Comprehensive Air Quality Characterization from Soil -Covered Open Detonation of...the short duration of the event, the heterogeneous emission concentra- tions, large plume lift, soil entrainment, and explosive safety restrictions...energetics and cased munitions, including Comp B, V453, and V548 munitions, were detonated without soil cover (only Comp B) or at soil cover depths of 3

Characterization of the Resource Potential of Martian Soil using the Integrated Dust/Soil Experiment Package (IDEP)

NASA Technical Reports Server (NTRS)

Cooper, Bonnie L.; Mckay, David S.; Allen, Carlton C.; Hoffman, John H.; Gittleman, Mark E.

1997-01-01

The Integrated Dust/Soil Experiment Package (IDEP) is a suite of instruments that can detect and quantify the abundances of useful raw materials on Mars. We focus here on its capability for resource characterization in the martian soil; however, it is also capable of detecting and quantifying gases in the atmosphere. This paper describes the scientific rationale and the engineering design behind the IDEP.

Initial data on biological activity of taiga-steppe soils in the lower reaches of the Kolyma River.

PubMed

Schelchkova, M V; Davydov, S P; Fyodorov-Davydov, D G; Davydova, A I; Boeskorov, G G; Solomonov, N G

2017-11-01

Microbiological and enzyme activities of extrazonal taiga-steppe soils in the lower reaches of the Kolyma River have been studied for the first time. Contrary to north-taiga cryometamorphic soils, predominating in the area, microbial cenoses under herb-sedge petrophytic and grass-sagebrush-herb thermophytic steppes are characterized by features typical for arid soils. The saturation of the soil profile with microorganisms is greater, and the development of actinomycetes is more intensive. The enzyme complex is characterized by high activity of dehydrogenases.

Natural 'background' soil water repellency in conifer forests: its prediction and relationship to wildfire occurrence

NASA Astrophysics Data System (ADS)

Doerr, Stefan; Woods, Scott; Martin, Deborah; Casimiro, Marta

2013-04-01

Soils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites (n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by col- lecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were fur- ther analyzed for repellency using WDPT and contact angle (hsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species (Pinus ponderosa, Pinus contorta, Picea engelma- nii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long- unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed (R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimen- tary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be pre- dicted with confidence from common terrain or soil variables. This work is presented in the memory of the late Scott Woods, who was instrumental in the success of this study and an inspiration to us all.

Use of Geochemical Indices in Environmental Assessment of Soil; the Predictable and the Predictably Unpredictable

NASA Astrophysics Data System (ADS)

Mikkonen, Hannah; Clarke, Bradley; van de Graaff, Robert; Reichman, Suzie

2016-04-01

Geochemical correlations between common contaminants (Pb, Ni, As, Cr, Co and Zn) and earth metals, Fe and Mn, have been recommended as empirical tools to estimate "background" concentrations of metals in soil. A limited number of studies indicate that geochemical ratios between Pb, Ni, As, Cr, Co, V and Zn with scavenger metals Fe or Mn, are consistent between soils collected from different regions (Hamon et al. 2004, Myers and Thorbjornsen 2004). These studies have resulted in the incorporation of geochemical indices into Australian guidance, for derivation of ecological investigation levels for Ni, Cr, Cu and Zn. However, little research has been undertaken to assess the variation of geochemical patterns between soils derived from different parent materials or different weathering environments. A survey of background soils derived from four different parent materials, across Victoria, Australia, was undertaken, comprising collection of samples (n=640) from the surface (0 to 0.1 m) and sub-surface (0.3 to 0.6 m). Soil samples were collected from urban and rural areas of low disturbance, away from point sources of contamination. Samples were analysed for metals/metalloids and soil physical and chemical properties. Statistical review of results included regression and multivariate analysis. The results of the soil survey were compared against geochemical relationships reported within Australia and internationally. Compilation of results from this study and international data sets, indicates that geochemical relationships for metals Cr and V (in the format of log[Cr] = alog[Fe] +c) are predictable, not only between soils derived from different parent materials, but also between soils of different continents. Conversely, relationships between Zn and Fe, Pb and Fe, Cu and Fe, Co and Mn are variable, particularly within soils derived from alluvial sediments, which may have undergone periods of reducing conditions, resulting in dissociation from metal oxides. Broad application of geochemical indices without an understanding of site specific conditions could result in significant underestimation of anthropogenic impacts to soil and potential risks to the environment. The reliability and application of geochemical indices for estimation of background concentrations will be discussed, including comment on statistical limitations, (such as management of censored results and the behaviour of composition data) and miss-use/miss-interpretation of geochemical indices within the environmental assessment industry, including inferences of causation based on empirical relationships. HAMON, R. E., MCLAUGHLIN, M. J., GILKES, R. J., RATE, A. W., ZARCINAS, B., ROBERTSON, A., COZENS, G., RADFORD, N. & BETTENAY, L. 2004. Geochemical indices allow estimation of heavy metal background concentrations in soils. Global Biogeochemical Cycles, 18, GB1014. MYERS, J. & THORBJORNSEN, K. 2004. Identifying Metals Contamination in Soil: A Geochemical Approach. Soil & Sediment Contamination, 13, 1-16.

Management practices affect soil nutrients and bacterial populations in backgrounding beef feedlot

USDA-ARS?s Scientific Manuscript database

Contaminants associated with manure in animal production sites are of significant concern. Unless properly managed, high soil nutrient concentrations in feedlots can deteriorate soil and water quality. This three year study tested a nutrient management strategy with three sequentially imposed manage...

Mercury content of Illinois soils

USGS Publications Warehouse

Dreher, G.B.; Follmer, L.R.

2004-01-01

For a survey of Illinois soils, 101 cores had been collected and analyzed to determine the current and background elemental compositions of Illinois soils. Mercury and other elements were determined in six samples per core, including a surface sample from each core. The mean mercury content in the surface samples was 33 ?? 20 ??g/kg soil, and the background content was 20 ?? 9 ??g/kg. The most probable sources of mercury in these soils were the parent material, and wet and dry deposition of Hg0 and Hg2+ derived from coal-burning power plants, other industrial plants, and medical and municipal waste incinerators. Mercury-bearing sewage sludge or other fertilizers applied to agricultural fields could have been the local sources of mercury. Although the mercury content correlated with organic carbon content or clay content in individual cores, when all the data were considered, there was no strong correlation between mercury and either the organic carbon or the clay-size content.

Spatial patterns of heavy metals in soil under different geological structures and land uses for assessing metal enrichments.

PubMed

Krami, Loghman Khoda; Amiri, Fazel; Sefiyanian, Alireza; Shariff, Abdul Rashid B Mohamed; Tabatabaie, Tayebeh; Pradhan, Biswajeet

2013-12-01

One hundred and thirty composite soil samples were collected from Hamedan county, Iran to characterize the spatial distribution and trace the sources of heavy metals including As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn, and Fe. The multivariate gap statistical analysis was used; for interrelation of spatial patterns of pollution, the disjunctive kriging and geoenrichment factor (EF(G)) techniques were applied. Heavy metals and soil properties were grouped using agglomerative hierarchical clustering and gap statistic. Principal component analysis was used for identification of the source of metals in a set of data. Geostatistics was used for the geospatial data processing. Based on the comparison between the original data and background values of the ten metals, the disjunctive kriging and EF(G) techniques were used to quantify their geospatial patterns and assess the contamination levels of the heavy metals. The spatial distribution map combined with the statistical analysis showed that the main source of Cr, Co, Ni, Zn, Pb, and V in group A land use (agriculture, rocky, and urban) was geogenic; the origin of As, Cd, and Cu was industrial and agricultural activities (anthropogenic sources). In group B land use (rangeland and orchards), the origin of metals (Cr, Co, Ni, Zn, and V) was mainly controlled by natural factors and As, Cd, Cu, and Pb had been added by organic factors. In group C land use (water), the origin of most heavy metals is natural without anthropogenic sources. The Cd and As pollution was relatively more serious in different land use. The EF(G) technique used confirmed the anthropogenic influence of heavy metal pollution. All metals showed concentrations substantially higher than their background values, suggesting anthropogenic pollution.

Evaluation on expansive performance of the expansive soil using electrical responses

NASA Astrophysics Data System (ADS)

Chu, Ya; Liu, Songyu; Bate, Bate; Xu, Lei

2018-01-01

Light structures, such as highways and railroads, built on expansive soils are prone to damages from the swelling of their underlain soil layers. Considerable amount of research has been conducted to characterize the swelling properties of expansive soils. Current swell characterization models, however, are limited by lack of standardized tests. Electrical methods are non-destructive, and are faster and less expensive than the traditional geotechnical methods. Therefore, geo-electrical methods are attractive for defining soil characteristics, including the swelling behavior. In this study, comprehensive laboratory experiments were undertaken to measure the free swelling and electrical resistivity of the mixtures of commercial kaolinite and bentonite. The electrical conductivity of kaolinite-bentonite mixtures was measured by a self-developed four-electrode soil resistivity box. Increasing the free swelling rate of the kaolinite-bentonite mixtures (0.72 to 1 of porosity of soils samples) led to a reduction in the electrical resistivity and an increase in conductivity. A unique relationship between free swelling rate and normalized surface conductivity was constructed for expensive soils by eliminating influences of porosity and m exponent. Therefore, electrical response measurement can be used to characterize the free swelling rate of expensive soils.

Characterizing Watersheds with Geophysical Methods: Some uses of GPR and EMI in Hydropedological Investigations.

NASA Astrophysics Data System (ADS)

Doolittle, J.; Lin, H.; Jenkinson, B.; Zhou, X.

2006-05-01

The USDA-NRCS and its cooperators use ground-penetrating radar (GPR) and electromagnetic induction (EMI) as rapid, noninvasive tools to support soil surveys at different scales and levels of resolution. The effective use of GPR is site-specific and generally restricted to soils having low electrical conductivity (e.g., soils with low clay and soluble salt contents). In suitable soils, GPR provides high resolution data, which are used to estimate depths to soil horizons and geologic layers that restrict, redirect, and/or concentrate the flow of water through landscapes. In areas of coarse-textured soils, GPR has been used to map spatiotemporal variations in water-table depths and local ground-water flow patterns. Compared with GPR, EMI can be effectively used across a broader spectrum of soils and spatial scales, but provides lower resolution of subsurface features. EMI is used to refine and improve soil maps prepared with traditional soil survey methods. Differences in apparent conductivity (ECa) are associated with different soils and soil properties (e.g., clay, moisture and soluble salt contents). Apparent conductivity maps provide an additional layer of information, which directs soil sampling, aids the identification and delineation of some soil polygons, and enhances the quality of soil maps. More recently, these tools were used to characterize the hydropedological character of a small, steeply sloping, forested watershed. Within the watershed, EMI was used to characterize the principal soil-landscape components, and GPR was used to provide high resolution data on soil depth and layering within colluvial deposits located in swales and depressional areas.

Soil Science Education for Primary and Secondary Students

NASA Astrophysics Data System (ADS)

Sparrow, Elena; Yoshikawa, Kenji; Kopplin, Martha

2013-04-01

Soils is one of the science investigation areas in the Global learning and Observations to Benefit the Environment (GLOBE), an international science and education program (112 countries) that teaches primary and secondary students to learn science by doing science. For each area of investigation GLOBE provides background information, measurement protocols and learning activities compiled as a chapter in the GLOBE Teacher's Guide. Also provided are data sheets and field guides to assist in the accurate collection of data as well as suggestions of scientific instruments and calibration methods. Teachers learn GLOBE scientific measurement protocols at professional development workshops led by scientists and educators, who then engage their students in soil studies that also contribute to ongoing science investigations. Students enter their data on the GLOBE website and can access their data as well as other data contributed by students from other parts of the world. Soil characterization measurements carried out in the field include site description, horizon depths, soil structure, soil color, soil consistence, soil texture, roots, rocks and carbonates. Other field measurements are soil temperature and soil moisture monitoring while the following measurements are carried out in the classroom or laboratory: gravimetric soil moisture, bulk density, particle density, particle size distribution, pH and soil fertility (nitrogen, phosphorus and potassium). Learning activities provide support for preparing students to do the measurements and for better understanding of science concepts. Many countries in GLOBE have adopted standards for education including science education with commonalities among them. For the Teacher's Guide, the National Science Education Standards published by the US National Academy of Sciences, selected additional content standards that GLOBE scientists and educators feel are appropriate and the National Geography Standards prepared by the (US) National Education Standards Project, are being used. Educational objectives for students include gaining scientific inquiry abilities in addition to understanding scientific concepts. The Soils chapter also includes some suggestions for managing students in the field and classroom. A new protocol has also been developed by the Seasons and Biomes project, one of the GLOBE earth system science projects. Active Layer monitoring uses a Frost Tube that measures when and how deeply soil freezes and is currently being used in more than 200 sites in Alaska. Teachers have successfully implemented soil studies in their curriculum and have used it to teach about the science process.

Characterization of Minerals: From the Classroom to Soils to Talc Deposits

ERIC Educational Resources Information Center

McNamee, Brittani D.

2013-01-01

This dissertation addresses different methods and challenges surrounding characterizing and identifying minerals in three environments: in the classroom, in soils, and in talc deposits. A lab manual for a mineralogy and optical mineralogy course prepares students for mineral characterization and identification by giving them the methods and tools…

Invasive scotch broom alters soil chemical properties in Douglas-fir forests of the Pacific Northwest, USA

Treesearch

Robert A. Slesak; Timothy B. Harrington; Anthony W. D′Amato

2016-01-01

Backgrounds and aims Scotch broom is an N-fixing invasive species that has high potential to alter soil properties. We compared soil from areas of Scotch broom invasion with nearby areas that had no evidence of invasion to assess the influence of broom on soil P fractions and other chemical properties. Methods The study was...

The impact of fog on soil moisture dynamics in the Namib Desert

NASA Astrophysics Data System (ADS)

Li, Bonan; Wang, Lixin; Kaseke, Kudzai F.; Vogt, Roland; Li, Lin; Seely, Mary K.

2018-03-01

Soil moisture is a crucial component supporting vegetation dynamics in drylands. Despite increasing attention on fog in dryland ecosystems, the statistical characterization of fog distribution and how fog affects soil moisture dynamics have not been seen in literature. To this end, daily fog records over two years (Dec 1, 2014-Nov 1, 2016) from three sites within the Namib Desert were used to characterize fog distribution. Two sites were located within the Gobabeb Research and Training Center vicinity, the gravel plains and the sand dunes. The third site was located at the gravel plains, Kleinberg. A subset of the fog data during rainless period was used to investigate the effect of fog on soil moisture. A stochastic modeling framework was used to simulate the effect of fog on soil moisture dynamics. Our results showed that fog distribution can be characterized by a Poisson process with two parameters (arrival rate λ and average depth α (mm)). Fog and soil moisture observations from eighty (Aug 19, 2015-Nov 6, 2015) rainless days indicated a moderate positive relationship between soil moisture and fog in the Gobabeb gravel plains, a weaker relationship in the Gobabeb sand dunes while no relationship was observed at the Kleinberg site. The modeling results suggested that mean and major peaks of soil moisture dynamics can be captured by the fog modeling. Our field observations demonstrated the effects of fog on soil moisture dynamics during rainless periods at some locations, which has important implications on soil biogeochemical processes. The statistical characterization and modeling of fog distribution are of great value to predict fog distribution and investigate the effects of potential changes in fog distribution on soil moisture dynamics.

[Review on water eco-environment in vegetation restoration in Loess Plateau].

PubMed

Hu, Liangjun; Shao, Mingan

2002-08-01

Water is the crucial factor influencing vegetation restoration and eco-environmental reconstruction in Loess Plateau region. In this paper, the previous studies on water eco-environment under vegetation construction were summarized from seven aspects, i.e., soil water resource, background of soil water, dynamics of soil water, dry soil layer, relationship between soil water and vegetarian productivity, classification of soil water position, and strategy for vegetation construction. Meanwhile, some problems in the relevant researches were pointed out and discussed.

Radiation dose in the high background radiation area in Kerala, India.

PubMed

Christa, E P; Jojo, P J; Vaidyan, V K; Anilkumar, S; Eappen, K P

2012-03-01

A systematic radiological survey has been carried out in the region of high-background radiation area in Kollam district of Kerala to define the natural gamma-radiation levels. One hundred and forty seven soil samples from high-background radiation areas and five samples from normal background region were collected as per standard sampling procedures and were analysed for (238)U, (232)Th and (40)K by gamma-ray spectroscopy. External gamma dose rates at all sampling locations were also measured using a survey meter. The activities of (238)U, (232)Th and (40)K was found to vary from 17 to 3081 Bq kg(-1), 54 to 11976 Bq kg(-1) and BDL (67.4 Bq kg(-1)) to 216 Bq kg(-1), respectively, in the study area. Such heterogeneous distribution of radionuclides in the region may be attributed to the deposition phenomenon of beach sand soil in the region. Radium equivalent activities were found high in several locations. External gamma dose rates estimated from the levels of radionuclides in soil had a range from 49 to 9244 nGy h(-1). The result of gamma dose rate measured at the sampling sites using survey meter showed an excellent correlation with dose rates computed from the natural radionuclides estimated from the soil samples.

The Biotoxicity of Mars Soils

NASA Technical Reports Server (NTRS)

Kerney, Krystal

2010-01-01

Recent evidence from the Opportunity and Spirit rovers suggests that the soils on Mars might be very high in biotoxic materials induding sulfate salts, chlorides, and acidifying agents. Yet, very little is known about how the chemistries of Mars soils might affect the survival and growth of terrestrial microorganisms. The primary objectives of the proposed research will be to: (1) prepare and characterize Mars analog soils amended with potential biotoxic levels of sulfates, chlorides, and acidifying minerals; (2) use the stimulants to conduct a series of toxicology assays to determine if terrestrial microorganisms from spacecraft or extreme environments can survive direct exposure to the biotoxic soils, and (3) mix soils from extreme environments on Earth into Mars analog soils to determine if terrestrial microorganisms can grow and replicate under Martian conditions. The Mars analog soils will be thoroughly characterized by a wide diversity of soil chemistry assays to determine the exact nature of the soluble biotoxic components following hydration. The microbial experiments will be designed to test the effects of Mars stimulants on microbial survival, growth and replication during direct challenge experiments. Toxicology experiments will be designed to mimic terrestrial microbes coming into contact with biotoxic soils with and without liquid water. Results are expected to help" ... characterize the limits of life in ... planetary environments ... " and may help constrain the search for life on Mars.

Improved Soil Erosion and Sediment Transport in GSSHA

DTIC Science & Technology

2010-08-01

the USLE soil erodibility factor (0-1), soil cropping factor (0-1) and conservation factor (0-1) in the development by Julien (1995). The use of one...factor K represents a departure from Julien (1995), who used all three factors from the Universal Soil Loss Equation ( USLE ). This departure is justi...runoff using a research-quality data set. BACKGROUND: GSSHA simulates overland soil erosion and outputs erosion and deposition for any size class of

Linking Carbon Flux Dynamics and Soil Structure in Dryland Soils

NASA Astrophysics Data System (ADS)

DeCarlo, K. F.; Caylor, K. K.

2016-12-01

Biological sources in the form of microbes and plants play a fundamental role in determining the magnitude of carbon flux. However, the geophysical structure of the soil (which the carbon must pass through before entering the atmosphere) often serves as a constraining entity, which has the potential to serve as instigators or mitigators of those carbon and hydrologic flux processes. We characterized soil carbon dynamics in three dryland soil systems: bioturbated soils, biocompacted soils, and undisturbed soils. Carbon fluxes were characterized using a closed-system respiration chamber, with CO2 concentration differences measured using an infrared gas analyzer (IRGA). Structure of the soil systems, with a focus on the macro-crack structure, were characterized using a combined resin-casting/X-ray imaging technique. Results show fundamental differences in carbon dynamics between the different soil systems/structures: control soils have gaussian distributions of carbon flux that decrease with progressive drying of the soil, while biocompacted soils exhibit exponentially distributed fluxes that do not regularly decrease with increased drying of the soil. Bioturbated soils also exhibit an exponential distribution of carbon flux, though at a much higher magnitude. These differences are evaluated in the context of the underlying soil structure: while the control soils exhibit a shallow and narrow crack structure, the biocompacted soils exhibit a "systematic" crack network with moderate cracking intensity and large depth. The deep crack networks of the biocompacted soils may serve to physically enhance an otherwise weak source of carbon via advection and/or convection, inducing fluxes that are equal or greater than an otherwise carbon-rich soil. The bioturbated soils exhibit a "surficial" crack network that is shallow but extensive, but additionally have deep holes known to convectively vent carbon, which may explain their periodically large carbon fluxes. Our results suggest that variability in soil structure, as well as carbon source, plays a fundamental role in carbon flux dynamics, and the importance of evaluating biological carbon source and geophysical soil structure in a dryland environment.

Mercury in soil gas and air--A potential tool in mineral exploration

USGS Publications Warehouse

McCarthy, Joseph Howard; Vaughn, W.W.; Learned, R.E.; Meuschke, J.L.

1969-01-01

The mercury content in soil gas and in the atmosphere was measured in several mining districts to test the possibility that the mercury content in the atmosphere is higher over ore deposits than over barren ground. At Cortez, Nev., the distribution of anorhalous amounts of mercury in the air collected at ground level (soil gas) correlates well with the distribution of gold-bearing rocks that are covered by as much as 100 feet of gravel. The mercury content in the atmosphere collected at an altitude of 200 feet by an aircraft was 20 times background over a mercury posit and 10 times background over two porphyry copper deposits. Measurement of mercury in soil gas and air may prove to be a valuable exploration tool.

Application of stochastic models in identification and apportionment of heavy metal pollution sources in the surface soils of a large-scale region.

PubMed

Hu, Yuanan; Cheng, Hefa

2013-04-16

As heavy metals occur naturally in soils at measurable concentrations and their natural background contents have significant spatial variations, identification and apportionment of heavy metal pollution sources across large-scale regions is a challenging task. Stochastic models, including the recently developed conditional inference tree (CIT) and the finite mixture distribution model (FMDM), were applied to identify the sources of heavy metals found in the surface soils of the Pearl River Delta, China, and to apportion the contributions from natural background and human activities. Regression trees were successfully developed for the concentrations of Cd, Cu, Zn, Pb, Cr, Ni, As, and Hg in 227 soil samples from a region of over 7.2 × 10(4) km(2) based on seven specific predictors relevant to the source and behavior of heavy metals: land use, soil type, soil organic carbon content, population density, gross domestic product per capita, and the lengths and classes of the roads surrounding the sampling sites. The CIT and FMDM results consistently indicate that Cd, Zn, Cu, Pb, and Cr in the surface soils of the PRD were contributed largely by anthropogenic sources, whereas As, Ni, and Hg in the surface soils mostly originated from the soil parent materials.

Estonian soil classification as a tool for recording information on soil cover and its matching with local site types, plant covers and humus forms classifications

NASA Astrophysics Data System (ADS)

Kõlli, Raimo; Tõnutare, Tõnu; Rannik, Kaire; Krebstein, Kadri

2015-04-01

Estonian soil classification (ESC) has been used successfully during more than half of century in soil survey, teaching of soil science, generalization of soil databases, arrangement of soils sustainable management and others. The Estonian normally developed (postlithogenic) mineral soils (form 72.4% from total area) are characterized by mean of genetic-functional schema, where the pedo-ecological position of soils (ie. location among other soils) is given by means of three scalars: (i) 8 stage lithic-genetic scalar (from rendzina to podzols) separates soils each from other by parent material, lithic properties, calcareousness, character of soil processes and others, (ii) 6 stage moisture and aeration conditions scalar (from aridic or well aerated to permanently wet or reductic conditions), and (iii) 2-3 stage soil development scalar, which characterizes the intensity of soil forming processes (accumulation of humus, podzolization). The organic soils pedo-ecological schema, which links with histic postlithogenic soils, is elaborated for characterizing of peatlands superficial mantle (form 23.7% from whole soil cover). The position each peat soil species among others on this organic (peat) soil matrix schema is determined by mean of 3 scalars: (i) peat thickness, (ii) type of paludification or peat forming peculiarities, and (iii) stage of peat decomposition or peat type. On the matrix of abnormally developed (synlithogenic) soils (all together 3.9%) the soil species are positioned (i) by proceeding in actual time geological processes as erosion, fluvial processes (at vicinity of rivers, lakes or sea) or transforming by anthropogenic and technological processes, and (ii) by 7 stage moisture conditions (from aridic to subaqual) of soils. The most important functions of soil cover are: (i) being a suitable environment for plant productivity; (ii) forming adequate conditions for decomposition, transformation and conversion of falling litter (characterized by humus cover type); (iii) being compartment for deposition of humus, individual organic compounds, plant nutrition elements, air and water, and (iv) forming (bio)chemically variegated active space for soil type specific edaphon. For studying of ESC matching with others ecosystem compartments classifications the comparative analysis of corresponding classification schemas was done. It may be concluded that forest and natural grasslands site types as well the plant associations of forests and grasslands correlate (match) well with ESC and therefore these compartments may be adequately expressed on soil cover matrixes. Special interest merits humus cover (in many countries known as humus form), which is by the issue natural body between plant and soil or plant cover and soil cover. The humus cover, which lied on superficial part of soil cover, has been formed by functional interrelationships of plants and soils, reflects very well the local pedo-ecological conditions (both productivity and decomposition cycles) and, therefore, the humus cover types are good indicators for characterizing of local pedo-ecological conditions. The classification of humus covers (humus forms) should be bound with soil classifications. It is important to develop a pedocentric approach in treating of fabric and functioning of natural and agro-ecosystems. Such, based on soil properties, ecosystem approach to management and protection natural resources is highly recommended at least in temperate climatic regions. The sound matching of soil and plant cover is of decisive importance for sustainable functioning of ecosystem and in attaining a good environmental status of the area.

Quantifying and mitigating the environmental impacts of using corn stover as a biofuel feedstock

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods Corn stover has been suggested as a viable biomass feedstock for bioenergy production. However, unharvested corn stover provides two important ecosystem services: it reduces soil erosion and replenishes soil carbon, both of which help maintain soil productivity. There are...

Root traits and soil properties in harvested perennial grassland, annual wheat, and never-tilled annual wheat

USDA-ARS?s Scientific Manuscript database

Background and aims: Root functional traits are determinants of soil carbon storage; plant productivity; and ecosystemproperties. However, few studies look at both annual and perennial roots, soil properties, and productivity in the context of field scale agricultural systems. Methods: In Long Term...

Hydrologic transport of fecal bacteria attenuated by flu gas desulfurized (FGD) gypsum

USDA-ARS?s Scientific Manuscript database

Background Flue gas desulfurized (FGD) gypsum is a byproduct of coal-fired power plants. As a soil amendment for crop production it has the potential of improving soil water infiltration, soil conservation, and decreasing nutrient losses from broiler litter applications. Because broiler litter is a ...

Biochar soil additions impacts herbicide fate: Importance of application timing and feedstock species

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Biochar (BC), solid biomass subjected to pyrolysis, can alter the fate of pesticides in soil. We investigated the effect of soil amendment with several biochars on the sorption, persistence, leaching and bioefficacy of the herbicides clomazone (CMZ) and bispyribac sodium (BYP). RESULTS:...

Soil, water, and vegetation conditions in south Texas

NASA Technical Reports Server (NTRS)

Wiegand, C. L.; Gausman, H. W.; Leamer, R. W.; Richardson, A. J.; Everitt, J. H.; Gerbermann, A. H. (Principal Investigator)

1977-01-01

The author has identified the following significant results. The best wavelengths in the 0.4 to 2.5 micron interval were determined for detecting lead toxicity and ozone damage, distinguishing succulent from woody species, and detecting silverleaf sunflower. A perpendicular vegetation index, a measure of the distance from the soil background line, in MSS 5 and MSS 7 data space, of pixels containing vegetation was developed and tested as an indicator of vegetation development and crop vigor. A table lookup procedure was devised that permits rapid identification of soil background and green biomass or phenological development in LANDSAT scenes without the need for training data.

Dalton Highway : characterization of foundation soils

DOT National Transportation Integrated Search

1984-09-01

In this report we represent the results of our geotechnical characterization of natural foundation soils along the Dalton Highway from the Livengood to Prudhoe Bay. In addition, it analyzes this data by statistical methods and caracterizes foundation...

Antibiotic Resistance Patterns of Major Zoonotic Pathogens from All-Natural, Antibiotic-Free, Pasture-Raised Broiler Flocks in the Southeastern United States.

PubMed

Rothrock, Michael J; Hiett, Kelli L; Guard, Jean Y; Jackson, Charlene R

2016-03-01

The use of antibiotics in agroecosystems has been implicated in the rise in antibiotic resistance (AR), which can affect environmental, animal, and human health. To determine the environmental impact of antibiotic use in agroecosystems, appropriate background levels of AR in agricultural environments in the absence of antibiotic application must be determined. Therefore, to determine background levels of AR in broiler production, four target microbes (, , , and ) were isolated from 15 all-natural, antibiotic-free, pasture-raised broiler flocks from six farms within the southeastern United States. The AR profiles of these isolates were characterized using the CDC National Antimicrobial Resistance Monitoring System for Enteric Bacteria (NARMS), and these resistance patterns were compared across target microbes and farms and throughout the life cycle of the flocks along the farm-to-fork continuum. Antibiotic resistances were most prevalent in and and least prevalent in . Although and were isolated from the same farms and characterized using the same NARMS plates, they exhibited distinct AR profiles, with demonstrating clear farm-specific resistance patterns. Multidrug resistance rates (three or more antibiotics), in order of prevalence, were (63.9%), (36.0%), (12.7%), and (1.4%). The results of this study demonstrate the variability in background AR among major food safety-related microbes, even when isolated from similar production and processing samples from the same farms, and indicate the need for the proper design of future broiler production studies to account for this highly dynamic background AR. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Spectroscopic Characteristics of Dissolved Organic Matter in Afforestation Forest Soil of Miyun District, Beijing

PubMed Central

Zhao, Chen; Shi, Zong-Hai; Zhong, Jun; Liu, Jian-Guo; Li, Jun-Qing

2016-01-01

In this study, soil samples collected from different plain afforestation time (1 year, 4 years, 10 years, 15 years, and 20 years) in Miyun were characterized, including total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), available K (K+), microbial biomass carbon (MBC), and dissolved organic carbon (DOC). The DOM in the soil samples with different afforestation time was further characterized via DOC, UV-Visible spectroscopy, excitation-emission matrix (EEM) fluorescence spectroscopy, and 1H NMR spectroscopy. The results suggested that the texture of soil sample was sandy. The extracted DOM from soil consisted mainly of aliphatic chains and only a minor aromatic component. It can be included that afforestation can improve the soil quality to some extent, which can be partly reflected from the indexes like TOC, TN, TP, K+, MBC, and DOC. And the characterization of DOM implied that UV humic-like substances were the major fluorophores components in the DOM of the soil samples, which consisted of aliphatic chains and aromatic components with carbonyl, carboxyl, and hydroxyl groups. PMID:27433371

Soil

USDA-ARS?s Scientific Manuscript database

Soil is a diverse natural material characterized by solid, liquid, and gas phases that impart unique chemical, physical, and biological properties. Soil provides many key functions, including supporting plant growth and providing environmental remediation. Monitoring key soil properties and processe...

Heavy metal contamination and ecological risk of farmland soils adjoining steel plants in Tangshan, Hebei, China.

PubMed

Yang, Liyun; Yang, Maomao; Wang, Liping; Peng, Fei; Li, Yuan; Bai, Hao

2018-01-01

The purpose of this study was to determine the heavy metal concentrations and ecological risks to farmland soils caused by atmospheric deposition adjoining five industrial steel districts in Tangshan, Hebei, China. A total of 39 topsoil samples from adjoining these plants were collected and analyzed for Pb, Zn, Cu, Cr, and As. The geo-accumulation index (Igeo) and potential ecological risk index (PERI) were calculated to assess the heavy metal pollution level in soils. The results showed that the levels of Pb and As in farmland soils adjoining all steel plants were more than the background value, with the As content being excessively high. The Cr and Cu contents of some samples were over the background values, but the Zn content was not. In all the research areas, the largest Igeo value of the heavy metals was for As, followed by Pb, and the largest monomial PERI ([Formula: see text]) was As, which showed that the pollution of As in farmland soils was significant and had considerable ecological risk. Additionally, the heavy metal sequential extraction experiments showed that Pb and Cr, which exceeded the background value, were present in about 20% of the exchangeable and carbonate-bound fractions in the soils surrounding some steel plants. This would imply the risk of these heavy metals being absorbed and accumulated by the crops. Therefore, the local government needs to control the pollution of heavy metals in the farmland soils adjoining the steel plant as soon as possible, in order to avoid possible ecological and food safety risks.

Urban enhancement of PM10 bioaerosol tracers relative to background locations in the Midwestern United States

NASA Astrophysics Data System (ADS)

Rathnayake, Chathurika M.; Metwali, Nervana; Baker, Zach; Jayarathne, Thilina; Kostle, Pamela A.; Thorne, Peter S.; O'Shaughnessy, Patrick T.; Stone, Elizabeth A.

2016-05-01

Bioaerosols are well-known immune-active particles that exacerbate respiratory diseases. Human exposures to bioaerosols and their resultant health impacts depend on their ambient concentrations, seasonal and spatial variation, and copollutants, which are not yet widely characterized. In this study, chemical and biological tracers of bioaerosols were quantified in respirable particulate matter (PM10) collected at three urban and three background sites in the Midwestern United States across four seasons in 2012. Endotoxins from Gram-negative bacteria (and a few Gram-positive bacteria), water-soluble proteins, and tracers for fungal spores (fungal glucans, arabitol, and mannitol) were ubiquitous and showed significant seasonal variation and dependence on temperature. Fungal spores were elevated in spring and peaked in summer, following the seasonal growing cycle, while endotoxins peaked in autumn during the row crop harvesting season. Paired comparisons of bioaerosols in urban and background sites revealed significant urban enhancements in PM10, fungal glucans, endotoxins, and water-soluble proteins relative to background locations, such that urban populations have a greater outdoor exposure to bioaerosols. These bioaerosols contribute, in part, to the urban excesses in PM10. Higher bioaerosol mass fractions in urban areas relative to background sites indicate that urban areas serve as a source of bioaerosols. Similar urban enhancements in water-soluble calcium and its correlation with bioaerosol tracers point toward windblown soil as an important source of bioaerosols in urban areas.

Petrographic characterization of lunar soils: Application of x ray digital-imaging to quantitative and automated analysis

NASA Technical Reports Server (NTRS)

Higgins, Stefan J.; Patchen, Allan; Chambers, John G.; Taylor, Lawrence A.; Mckay, David S.

1994-01-01

The rocks and soils of the moon will be the raw materials for various engineering needs at a lunar base, such as sources of hydrogen, oxygen, metals, etc. The material of choice for most of the bulk needs is the regolith and its less than 1 cm fraction, the soil. For specific mineral resources it may be necessary to concentrate minerals from either rocks or soils. Therefore, quantitative characterizations of these rocks and soils are necessary in order to better define their mineral resource potential. However, using standard point-counting microscopic procedures, it is difficult to quantitatively determine mineral abundances and virtually impossible to obtain data on mineral distributions within grains. As a start to fulfilling these needs, Taylor et al. and Chambers et al. have developed a procedure for characterization of crushed lunar rocks using x ray digital imaging. The development of a similar digital imaging procedure for lunar soils as obtained from a spectrometer is described.

Assessment of heavy metal accumulation in macrophyte, agricultural soil, and crop plants adjacent to discharge zone of sponge iron factory

NASA Astrophysics Data System (ADS)

Gupta, S.; Nayek, S.; Saha, R. N.; Satpati, S.

2008-08-01

The present study deals with the characterization of effluent released from sponge iron industries and distribution of heavy metals in soil and macrophytes near to effluent discharge channel. Apart from this, accumulation of heavy metals in nearby soil and vegetation system irrigated with effluent-contaminated water is also the subject of this study. Physico-chemical analysis of effluent reveals that the concentration of total suspended solids (TSS), total hardness (TH), iron (Fe2+), and oil and grease are greater than the IS (1981) norms for discharge of water into inland water body. The soil along the sides of the effluent channel also shows higher concentration of heavy metals than the background soil. The enrichment of the heavy metals are in the order of Chromium (Cr) > Iron (Fe) > Manganese (Mn) > Zinc (Zn) > Copper (Cu) > Cadmium (Cd). Macrophytes growing along the sides of the effluent channel also show significant accumulation of heavy metals almost in the same order as accumulated in soil. Higher uptake of heavy metals by these varieties reveals that these species can be used for future phytoremediation. The effluent as well as contaminated water is extensively used for irrigation for growing vegetables like tomato ( Lycopersicon esculatum) in the surrounding areas. Heavy metal accumulation in this agricultural soil are in the sequence of Cr > Fe > Mn > Zn > Cu > Cd. More or less similar type of accumulation pattern are also found in tomato plants except Fe and Zn exceeding Cr and Mn. Transfer Factor of heavy metals from soil to tomato plants (TFS) shows average value of <1, suggesting less uptake of heavy metals from soil. Among the plant parts studied, fruit shows least accumulation. Although tomato plants show some phenotypic changes, the survival of tomato plants as well as least accumulation of metals in fruit reveals their tolerance to heavy metals. Therefore it may be suggested that this plant can be grown successfully in the heavy metal contaminated soil. Further research work on in situ toxicity test will be necessary in order to identify the most resistive variety on this particular type of contaminated site.

Corrosion and Coatings Review of Specifications and Drawings of Facilities for the Oman Military Construction Program at Masirah Island, Oman.

DTIC Science & Technology

1984-12-01

5 Background Objective Approach Scope of Work Organization 2 SUMMARY OF ENVIRONMENTAL CONDITIONS AT MASIRAH ISLAND ................. 7 Soil ...CONDITIONS AT MASIRAH ISLAND Soil Resistivity Values for the soil resistivity at this location are not readily avail- able. It is, however, considered...to be a very aggressive soil with high amounts of chlorides and sulfates, which can be converted to corrosive sul- -. fides. Soil samples will be

Watershed-scale assessment of background concentrations and guidance values for heavy metals in soils from a semiarid and coastal zone of Brazil.

PubMed

da Silva, Yuri Jacques Agra Bezerra; do Nascimento, Clístenes Williams Araújo; Cantalice, José Ramon Barros; da Silva, Ygor Jacques Agra Bezerra; Cruz, Cinthia Maria Cordeiro Atanázio

2015-09-01

Determining heavy metal background concentrations in soils is fundamental in order to support the monitoring of potentially contaminated areas. This is particularly important to areas submitted to high environmental impact where an intensive and local monitoring is required. To this end, the aim of this study was to establish background concentrations and quality reference values (QRVs) for the heavy metals Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, As, and Hg in an environmentally impacted watershed from Brazil. Geochemical associations among Fe, Mn, and trace elements were also assessed to provide an alternative tool for establishing background concentrations. A total of one hundred and four samples comprised twenty-six composite soil samples from areas of native forest or minimal anthropic influence. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES, except for As and Hg measured by atomic absorption spectrophotometer. Background concentrations of heavy metals in soils had the following decreasing order: Fe > Mn > Zn > Cr > Pb > Ni > Cu > As > Cd > Hg. These values were usually lower than those observed in the international and national literature. The QRVs for Ipojuca watershed followed the order (mg kg(-1)) Fe (13,020.40) > Mn (91.80) > Zn (30.12) > Cr (15.00) > Pb (13.12) > Cu (3.53) > Ni (3.30) > As (0.51) > Cd (0.08) > Hg (0.04). Significant correlation among Fe, Mn, and heavy metals shows that solubilization by the method 3051A provides a reasonable estimate for predicting background concentrations for Cd, Cr, and Cu as well as Zn, Cr, Cu, and Ni.

Soils of the Summer Garden (Saint Petersburg)

NASA Astrophysics Data System (ADS)

Matinyan, N. N.; Bakhmatova, K. A.; Korentsvit, V. A.

2017-06-01

Soils of the Summer Garden—the first regular (French-style) garden in Russia—are characterized on the basis of the materials of field study performed during reconstruction of the garden in 2005-2011. Most of these soils are filled soils—urbostratozems—underlain by the loamy sands deposited in the Littorina Sea or by the buried gray-humus gleyic and gleyed soils. Urbostratozems are characterized by the slightly acid reaction in the topsoil horizons and slightly alkaline reaction in the middle-profile and lower horizons. The humus content in them varies from 0.2 to 6.8%; in the buried gray-humus soils, it is within 1.3-2.6%. The soils of the garden are characterized by the high and extremely high content of available phosphorus and the predominantly low content of available potassium as determined by Machigin's method. The bulk content of Pb in the surface soil horizons during the period of our study exceeded the maximum permissible concentration by 3-20 times; the bulk contents of Cu and Zn exceeded the tentative permissible concentrations for coarse-textured soils by 2-6 and 4-20 times, respectively. The main sources of the soil contamination by the heavy metals are the nearby highways. Local contaminated area was also found near the household yard.

Soils of the Sylvania Wilderness-Recreation Area, western Upper Peninsula, Michigan.

Treesearch

James G. Bockheim; J.K. Jordan

2004-01-01

Characterizes 22 soil profiles in teh Sylvania Wilderness-Recreation Area on the Ottawa National Forest, including soil descriptions and laboratory data. A soil map at a scale of 1:24,000 is provided. The genesis of the soils is discussed.

WIRE project- Soil water repellence in biodiverse semi arid environments: new insights and implications for ecological restoration

NASA Astrophysics Data System (ADS)

Muñoz-Rojas, Miriam; Jiménez-Morillo, Nicasio T.; Jordan, Antonio; Zavala, Lorena M.; Stevens, Jason; González-Pérez, Jose Antonio

2017-04-01

Background Soil water repellency (SWR) can have a critical effect on the restoration of disturbed ecosystems causing poor plant establishment and promoting erosion processes. Although SWR has been reported in most continents of the world for different soil types, climate conditions and land uses, there are still many research gaps in the knowledge of its causes and controlling factors (Doerr et al.,2000; Jordan et al., 2013), particularly in Mediterranean arid semi arid environments which are largely affected by this phenomenon. The WIRE project aims to investigate SWR in soils under different vegetation types of dominant biodiverse ecosystems of Western Australia (WA), e.g. hummock grasslands and Banksia woodlands, as well as characterizing organic compounds that induce hydrophobicity in these soils. Banksia woodlands (BW) are of particular interest in this project. These are iconic ecosystems of WA composed by an overstorey dominated by Proteaceae that are threatened by sand mining activities and urban expansion. Conservation and restoration of these woodlands are critical but despite considerable efforts to restore these areas, the success of current rehabilitation programs is poor due to the high sensitivity of the ecosystem to drought stress and the disruption of water dynamics in mature BW soils that result in low seedling survival rates (5-30%). The main objectives of this collaborative research are: i) to identify SWR intensity and severity under different vegetation types and evaluate controlling factors in both hummock grasslands and BW (ii) to characterize hydrophobic compounds in soils using analytical pyrolysis techniques and iii) to investigate the impact of SWR on water economy in relation with soil functioning and plant strategies for water uptake in pristine BW. Methods In a series of field trials and experimental studies, we measured SWR of soil samples under lab conditions in oven-dry samples (48 h, 105 °C) that were previously collected under the canopy of a broad range of plant species composing the dominant vegetation communities of the study areas. Direct analytical pyrolysis (Py-GC/MS) allowed the structural characterization of soil organic matter (SOM) (Jiménez-Morillo et al., 2014). Basic soil physicochemical properties were analysed and soil microbial activity was measured with the 1-day CO2 test, which determine soil microbial respiration rate based on the measurement of the CO2 burst produced after moistening dry soil (Muñoz-Rojas et al., 2016). Results Main results of the project revealed that SWR is strongly correlated to microbial activity, pH and electrical conductivity. In soil samples under Banksia spp., Py-GC/MS analysis showed that SOM had clear signs of alteration (humified) that included a high contribution of stable families like unspecific aromatic compounds and alkane/alkene pairs. However, under Eucalyptus spp. soils showed a less altered SOM with a high relative contribution from lignocellulose (lignin and carbohydrates), together with a low relative content of recalcitrant families. In soil samples from hummock grasslands of the Pilbara region, very low contents of SOM were found. These results point to possible indirect links between organic substances released by roots and soil wettability involving soil microorganisms. Ecological plant strategies and specific adaptations for water uptake in arid and semi-arid ecosystems of WA are likely the main drivers of SWR. ACKNOWLEDGEMENTS This research has been funded by the University of Western Australia (Research Collaboration Award 2015: 'Soil water repellence in biodiverse semi arid environments: new insights and implications for ecological restoration') and the Spanish Ministry of Economy and Competitiveness (research projects GEOFIRE, CGL2012-38655-C04- 01, and POSTFIRE, CGL 2013-47862-C2-1-R. References Doerr SH, Shakesby RA, Walsh RPD. 2000. Soil water repellency: its causes, characteristics and hydrogeomorphological significance. Earth-Sci Rev 51: 33-65. DOI: 10.1016/S0012-8252(00)00011-8. Jiménez-Morillo NT, González-Pérez JA, Jordán A, Zavala LM, de la Rosa JM, Jiménez-González MA, González- Vila FJ. 2014 Organic matter fractions controlling soil water repellency in sandy soils from the Doñana National Park (Southwestern Spain). Land Degrad. Develop. published online. DOI: 10.1002/ldr.2314 Jordán A, Zavala LM, Mataix-Solera J, Doerr SH. 2013. Soil water repellency: origin, assessment and geomorphological consequences. Catena 108, 1-8. DOI: 10.1016/j.catena.2013.05.005 Muñoz-Rojas M, Erickson TE, Martini D, Dixon KW, Merritt DJ. 2016. Soil physicochemical and microbiological indicators of short, medium and long term post-fire recovery in semi-arid ecosystems. Ecological indicators 63, 14-22.DOI: 10.1016/j.ecolind.2015.11.038

Evaluation of fine soil moisture data from the IFloodS (NASA GPM) Ground Validation campaign using a fully-distributed ecohydrological model

NASA Astrophysics Data System (ADS)

Bastola, S.; Dialynas, Y. G.; Arnone, E.; Bras, R. L.

2014-12-01

The spatial variability of soil, vegetation, topography, and precipitation controls hydrological processes, consequently resulting in high spatio-temporal variability of most of the hydrological variables, such as soil moisture. Limitation in existing measuring system to characterize this spatial variability, and its importance in various application have resulted in a need of reconciling spatially distributed soil moisture evolution model and corresponding measurements. Fully distributed ecohydrological model simulates soil moisture at high resolution soil moisture. This is relevant for range of environmental studies e.g., flood forecasting. They can also be used to evaluate the value of space born soil moisture data, by assimilating them into hydrological models. In this study, fine resolution soil moisture data simulated by a physically-based distributed hydrological model, tRIBS-VEGGIE, is compared with soil moisture data collected during the field campaign in Turkey river basin, Iowa. The soil moisture series at the 2 and 4 inch depth exhibited a more rapid response to rainfall as compared to bottom 8 and 20 inch ones. The spatial variability in two distinct land surfaces of Turkey River, IA, reflects the control of vegetation, topography and soil texture in the characterization of spatial variability. The comparison of observed and simulated soil moisture at various depth showed that model was able to capture the dynamics of soil moisture at a number of gauging stations. Discrepancies are large in some of the gauging stations, which are characterized by rugged terrain and represented, in the model, through large computational units.

Estimating Children’s Soil/Dust Ingestion Rates through Retrospective Analyses of Blood Lead Biomonitoring from the Bunker Hill Superfund Site in Idaho

EPA Science Inventory

Background: Soil/dust ingestion rates are important variables in assessing children’s health risks in contaminated environments. Current estimates are based largely on soil tracer methodology, which is limited by analytical uncertainty, small sample size, and short study du...

Assessment of soil-gas, seep, and soil contamination at the North Range Road Landfill, Fort Gordon, Georgia, 2008-2009

USGS Publications Warehouse

Landmeyer, James E.; Falls, W. Fred; Ratliff, W. Hagan; Wellborn, John B.

2011-01-01

Inorganic concentrations in all four soil samples did not exceed regional screening levels established by the U.S. Environmental Protection Agency. Barium concentrations, however, were two to three times higher than the background concentrations reported in similar Coastal Plain sediments of South Carolina.

A Standardized Soil Ecotoxicological Test Using Red Worms (Eisenia fetida).

ERIC Educational Resources Information Center

Paradise, Christopher J.

2001-01-01

Describes a simple, inexpensive test for soil contamination that can be used in a variety of courses to examine the effects of soil toxicity, to practice standardized laboratory procedures, to study experimental design and data analysis, or to investigate earthworm ecology. Presents background information along with details regarding equipment,…

77 FR 67777 - National Oil and Hazardous Substance Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-14

... subsequent soil samples showed levels of metals at or below generic residential criteria or background values... 1994- 1996 and additional sampling between 1998 and 2007. Area A--Site Entrance: Soil boring samples... verification samples. Additional soil samples were collected from the same location as the previous collection...

Toxicological benchmarks for screening potential contaminants of concern for effects on terrestrial plants: 1994 revision

DOE Office of Scientific and Technical Information (OSTI.GOV)

Will, M.E.; Suter, G.W. II

1994-09-01

One of the initial stages in ecological risk assessment for hazardous waste sites is screening contaminants to determine which of them are worthy of further consideration as contaminants of potential concern. This process is termed contaminant screening. It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a setmore » of phytotoxicity benchmarks for 38 chemicals potentially associated with United States Department of Energy (DOE) sites. In addition, background information on the phytotoxicity and occurrence of the chemicals in soils is presented, and literature describing the experiments from which data were drawn for benchmark derivation is reviewed. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern.« less

Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Terrestrial Plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Suter, G.W. II

1993-01-01

One of the initial stages in ecological risk assessment for hazardous waste sites is screening contaminants to determine which of them are worthy of further consideration as contaminants of potential concern. This process is termed contaminant screening. It is performed by comparing measured ambient concentrations of chemicals to benchmark concentrations. Currently, no standard benchmark concentrations exist for assessing contaminants in soil with respect to their toxicity to plants. This report presents a standard method for deriving benchmarks for this purpose (phytotoxicity benchmarks), a set of data concerning effects of chemicals in soil or soil solution on plants, and a setmore » of phytotoxicity benchmarks for 38 chemicals potentially associated with United States Department of Energy (DOE) sites. In addition, background information on the phytotoxicity and occurrence of the chemicals in soils is presented, and literature describing the experiments from which data were drawn for benchmark derivation is reviewed. Chemicals that are found in soil at concentrations exceeding both the phytotoxicity benchmark and the background concentration for the soil type should be considered contaminants of potential concern.« less

X-Ray Amorphous Phases in Terrestrial Analog Volcanic Sediments: Implications for Amorphous Phases in Gale Crater, Mars

NASA Technical Reports Server (NTRS)

Smith, R. J.; Horgan, B.; Rampe, E.; Dehouck, E.; Morris, R. V.

2017-01-01

X-ray diffraction (XRD) amorphous phases have been found as major components (approx.15-60 wt%) of all rock and soil samples measured by the CheMin XRD instrument in Gale Crater, Mars. The nature of these phases is not well understood and could be any combination of primary (e.g., glass) and secondary (e.g., allophane) phases. Amorphous phases form in abundance during surface weathering on Earth. Yet, these materials are poorly characterized, and it is not certain how properties like composition and structure change with formation environment. The presence of poorly crystalline phases can be inferred from XRD patterns by the appearance of a low angle rise (< or approx.10deg 2(theta)) or broad peaks in the background at low to moderate 2(theta) angles (amorphous humps). CheMin mineral abundances combined with bulk chemical composition measurements from the Alpha Particle X-ray Spectrometer (APXS) have been used to estimate the abundance and composition of the XRD amorphous materials in soil and rock samples on Mars. Here we apply a similar approach to a diverse suite of terrestrial samples - modern soils, glacial sediments, and paleosols - in order to determine how formation environment, climate, and diagenesis affect the abundance and composition of X-ray amorphous phases.

PCDD/Fs in air and soil around an e-waste dismantling area with open burning of insulated wires in south China.

PubMed

Ren, M; Tang, Y H; Peng, P A; Cai, Y

2015-05-01

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air and farmland soil sampled in 2006 around an e-waste dismantling area with open burning of insulated wires in Longtang in south China were investigated. The total toxic equivalent concentrations of PCDD/Fs were 3.2-31.7 pg/m(3) in air and 5.8 12.4 ng/kg in farmland soil at an e-waste site and 0.063-0.091 pg/m(3) in air at a background site. PCDD/Fs in the air at the e-waste site were characterized with dominant 1,2,3,4,6,7,8-HpCDF and OCDF and higher concentrations of furans than dioxins, suggesting open burning of insulated wires was likely to be the main source of PCDD/Fs. Compared with the results in this study, the level of PCDD/F tended to lessen with the average TEQ concentration decreasing by 41 % and the pattern changed to be dominated by OCDD in the air of Longtang in 2010 when insulated wires were openly burned in only a small scale. Our results indicate that the lower chlorinated congeners with higher vapor pressures have enhanced atmospheric transport tendencies.

Assessment of natural radioactivity levels in soil samples from some areas in Assiut, Egypt.

PubMed

El-Gamal, Hany; Farid, M El-Azab; Abdel Mageed, A I; Hasabelnaby, M; Hassanien, Hassanien M

2013-12-01

The natural radioactivity of soil samples from Assiut city, Egypt, was studied. The activity concentrations of 28 samples were measured with a NaI(Tl) detector. The radioactivity concentrations of (226)Ra, (232)Th, and (40)K showed large variations, so the results were classified into two groups (A and B) to facilitate the interpretation of the results. Group A represents samples collected from different locations in Assiut and characterized by low activity concentrations with average values of 46.15 ± 9.69, 30.57 ± 4.90, and 553.14 ± 23.19 for (226)Ra, (232)Th, and (40)K, respectively. Group B represents samples mainly collected from the area around Assiut Thermal Power Plant and characterized by very high activity concentrations with average values of 3,803 ± 145, 1,782 ± 98, and 1,377 ± 78 for (226)Ra, (232)Th, and (40)K, respectively. In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose rate (E), the external hazard index (H ex), and the annual gonadal dose equivalent (AGDE) have been calculated and compared with the internationally approved values. For group A, the calculated averages of these parameters are in good agreement with the international recommended values except for the absorbed dose rate and the AGDE values which are slightly higher than the international recommended values. However, for group B, all obtained averages of these parameters are much higher by several orders of magnitude than the international recommended values. The present work provides a background of radioactivity concentrations in the soil of Assiut.

Characterizing Spatiotemporal Dynamics of Methane Emissions from Rice Paddies in Northeast China from 1990 to 2010

PubMed Central

Zhang, Yuan; Su, Shiliang; Zhang, Feng; Shi, Runhe; Gao, Wei

2012-01-01

Background Rice paddies have been identified as major methane (CH4) source induced by human activities. As a major rice production region in Northern China, the rice paddies in the Three-Rivers Plain (TRP) have experienced large changes in spatial distribution over the recent 20 years (from 1990 to 2010). Consequently, accurate estimation and characterization of spatiotemporal patterns of CH4 emissions from rice paddies has become an pressing issue for assessing the environmental impacts of agroecosystems, and further making GHG mitigation strategies at regional or global levels. Methodology/Principal Findings Integrating remote sensing mapping with a process-based biogeochemistry model, Denitrification and Decomposition (DNDC), was utilized to quantify the regional CH4 emissions from the entire rice paddies in study region. Based on site validation and sensitivity tests, geographic information system (GIS) databases with the spatially differentiated input information were constructed to drive DNDC upscaling for its regional simulations. Results showed that (1) The large change in total methane emission that occurred in 2000 and 2010 compared to 1990 is distributed to the explosive growth in amounts of rice planted; (2) the spatial variations in CH4 fluxes in this study are mainly attributed to the most sensitive factor soil properties, i.e., soil clay fraction and soil organic carbon (SOC) content, and (3) the warming climate could enhance CH4 emission in the cool paddies. Conclusions/Significance The study concluded that the introduction of remote sensing analysis into the DNDC upscaling has a great capability in timely quantifying the methane emissions from cool paddies with fast land use and cover changes. And also, it confirmed that the northern wetland agroecosystems made great contributions to global greenhouse gas inventory. PMID:22235268

Local cartography of persistent organic pollutants (PCDD/F, PCB) concentrations in soils of three French departments. How to define background concentrations?

NASA Astrophysics Data System (ADS)

Clozel, Blandine

2017-04-01

As part of the Regional Health Plan for the Rhône-Alpes area (France), a cartography of soil contamination by persistent organic pollutants (dioxins/furans (PCDD/PCDF) and polychlorinated biphenyls (PCB)) was undertaken in order to define the background concentrations of soils located away from point source pollution. In the natural environment, PCDD/PCDF and PCB comes from air pollution and accumulate in the upper part of the soils. To define the background concentration of persistent organic pollutants from diffuse atmospheric origin in soils, sampling was carried out within the first 5 centimeters of soils that have been very little anthropized and untilled for more than 15 years. In such soils mixing and dilution of the pollutants is very limited. 170 samples were collected following a systematic plan of grid type (mesh of 8 x 8 km) in an area of 14 000km2, avoiding soil of high altitude and from urban area. Beyond their total concentration, the ratio of the congeners of PCBs (7 indicators and 12 dioxin-like) and of the 17 dioxins/furans was also used for interpretation. As expected, the concentrations in pollutants are globally lower in the rural zones than in the more industrialized ones. However, the pollutants are relatively enriched in valleys, confirming that the meteorological conditions and the local topography play a significant role in the repartition of the diffuse atmospheric pollution. For the vast majority of samples, even some of those presenting the highest total concentration, the ratio of the various congeners argues for an ancient origin of the contamination. All studies at the French or European level of the atmospheric concentration of organic pollutants indicate a progressive decrease in emissions of these contaminants for about 20 years. However, the soils have been receptors since a long time and such pollutants have accumulated. The congeners ratio give evolved signature of pollution indicating, on one hand, it is mainly due to past activities but, on the other hand, indicate that it will persist because of its high stability. These results show the importance of knowing the spatial distribution of the concentrations of PCDD/PCDF and PCB and taking into account the signature of their congeners when defining the reference value of background concentration which are applied to distinguish a recent point source pollution

Characterizing the phosphorus forms extracted from soil by the Mehlich III soil test

USDA-ARS?s Scientific Manuscript database

Phosphorus (P) can limit crop production in many soils, but P loss from soils may impair water quality; soil testing can guide fertilizer recommendations to optimize crop growth while minimizing P loss. The Mehlich III (M3) soil test is widely used in North America, followed by colorimetric analysis...

Source and Assessment of Metal Pollution at Khetri Copper Mine Tailings and Neighboring Soils, Rajasthan, India.

PubMed

Punia, Anita; Siddaiah, N Siva; Singh, Saurabh K

2017-11-01

We present here the results of the study on metal pollution by identifying source, abundance and distribution in soil and tailings of Khetri copper complex (KCC) mines, Rajasthan India. The region is highly contaminated by copper (Cu) with higher values in the soil near overburden material (1224 mg/kg) and tailings (111 mg/kg). The average Cu (231 mg/kg) concentration of soil is ~9, 5 and 32 times higher than upper crust, world average shale (WAS) and local background soil (LS), respectively. However this reaches to ~82, 46 and 280 times higher in case of tailing when compared. The correlation and principal component analysis for soil reveals that the source of Cu, Zn, Co, Ni, Mn and Fe is mining and Pb and Cd could be result of weathering of parent rocks and other anthropogenic activities. The source for Cr in soil is both mining activities and weathering of parent rocks. The values of index of geo-accumulation (I geo ) and pollution load index for soil using LS as background are higher compared to values calculated using WAS. The metal rich sulphide bearing overburden material as well as tailings present in the open environment at KCC mines region warrants a proper management to minimize their impact on the environment.

Characterizing soil erosion potential using electrical resistivity imaging : final report.

DOT National Transportation Integrated Search

2017-04-01

The erosion rate, or erodibility, of soil depends on many soil characteristics including: plasticity, : water content, grain size, percent clay, compaction, and shear strength. Many of these characteristics also : influence soil in situ bulk electric...

A Study of Soil and Duricrust Models for Mars

NASA Astrophysics Data System (ADS)

Bishop, J. L.

2001-03-01

Analysis of soil and duricrust formation mechanisms on Mars. Soil analog mixtures have been prepared, characterized and tested through wet/dry cycling experiments; results are compared with Mars Pathfinder soil data (spectral, chemical and magnetic).

Characterizing soil erosion potential using electrical resistivity imaging : technical summary.

DOT National Transportation Integrated Search

2017-04-01

The erosion rate, or erodibility, of soil depends on many soil characteristics : including: plasticity, water content, grain size, percent clay, compaction, and shear : strength. Many of these characteristics also influence soil in situ bulk electric...

Evaluation of contaminants retention in soils from Viamão District, Rio Grande do Sul State, Brazil

NASA Astrophysics Data System (ADS)

Herlinger, Ronaldo; Viero, Antonio Pedro

2006-05-01

Adsorption is one of the most significant processes in the mobility of soluble pollutants in soils. The aim of this work is to characterize and evaluate the adsorption capacity of soils from Viamão District, Brazil. The studied ions were leadtotal, coppertotal, sulfate, phosphate, and potassium. The soils were mapped by remote sensing and characterized by granulometrical and mineralogical techniques. The adsorption tests were made by the contact of soil samples with aqueous solutions. The soils adsorption capacity presented the following trend: Pbtotal>Cutotal≈PO{4/3-}>K+ ≈SO{4/2+}. Adsorption in the soils is strongly influenced by clay content. The adsorption of phosphate, copper, and lead was accentuated by the presence of organic matter. Phosphate adsorption was controlled by oxides and organic matter. Both potassium and sulfate showed insignificant adsorption in the studied soils.

Calibration of an Ultra-Low-Background Proportional Counter for Measuring 37Ar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seifert, Allen; Aalseth, Craig E.; Bonicalzi, Ricco

Abstract. An ultra-low-background proportional counter (ULBPC) design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electrochemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) constructed at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with 14C/3H, age-dating of groundwater with 39Ar, and soil-gas assay for 37Ar to support On-Site Inspection (OSI). On-Site Inspection is a key componentmore » of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of 37Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of 37Ar samples over a broad range of pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for 37Ar soil gas background studies.« less

Source identification of eight hazardous heavy metals in agricultural soils of Huizhou, Guangdong Province, China.

PubMed

Cai, Limei; Xu, Zhencheng; Ren, Mingzhong; Guo, Qingwei; Hu, Xibang; Hu, Guocheng; Wan, Hongfu; Peng, Pingan

2012-04-01

One hundred and four surface samples and 40 profiles samples in agricultural soils collected from Huizhou in south-east China were monitored for total contents of 8 heavy metals, and analyzed by multivariate statistical techniques and enrichment factor (EF), in order to investigate their origins. The results indicate that the concentrations of Cu, Zn, Ni, Cr, Pb, Cd, As and Hg in soils are 16.74, 57.21, 14.89, 27.61, 44.66, 0.10, 10.19 and 0.22 mg/kg, respectively. Compared to the soil background contents in Guangdong Province, the mean concentrations of Hg, Cd, Zn, Pb and As in soil of Huizhou are higher, especially Hg and Cd, which are 2.82 and 1.79 times the background values, respectively. Cr, Ni, Cu, partially, Zn and Pb mainly originate from a natural source. Cd, As, partially, Zn mainly come from agricultural practices. However, Hg, partially, Pb originate mainly from industry and traffic sources. Copyright © 2011 Elsevier Inc. All rights reserved.

LAI inversion from optical reflectance using a neural network trained with a multiple scattering model

NASA Technical Reports Server (NTRS)

Smith, James A.

1992-01-01

The inversion of the leaf area index (LAI) canopy parameter from optical spectral reflectance measurements is obtained using a backpropagation artificial neural network trained using input-output pairs generated by a multiple scattering reflectance model. The problem of LAI estimation over sparse canopies (LAI < 1.0) with varying soil reflectance backgrounds is particularly difficult. Standard multiple regression methods applied to canopies within a single homogeneous soil type yield good results but perform unacceptably when applied across soil boundaries, resulting in absolute percentage errors of >1000 percent for low LAI. Minimization methods applied to merit functions constructed from differences between measured reflectances and predicted reflectances using multiple-scattering models are unacceptably sensitive to a good initial guess for the desired parameter. In contrast, the neural network reported generally yields absolute percentage errors of <30 percent when weighting coefficients trained on one soil type were applied to predicted canopy reflectance at a different soil background.

High natural erosion rates are the backdrop for enhanced anthropogenic soil erosion in the Middle Hills of Nepal

NASA Astrophysics Data System (ADS)

West, A. J.; Arnold, M.; Aumaître, G.; Bourlès, D. L.; Keddadouche, K.; Bickle, M.; Ojha, T.

2014-08-01

Although agriculturally accelerated soil erosion is implicated in the unsustainable environmental degradation of mountain environments, such as in the Himalaya, the effects of land use can be difficult to quantify in many mountain settings because of the high and variable natural background rates of erosion. In this study, we present new long-term denudation rates, derived from cosmogenic 10Be analysis of quartz in river sediment from the Likhu Khola, a small agricultural river basin in the Middle Hills of central Nepal. Calculated long-term denudation rates, which reflect background natural erosion processes over 1000+ years prior to agricultural intensification, are similar to present-day sediment yields and to soil loss rates from terraces that are well-maintained. Similarity in short- and long-term catchment-wide erosion rates for the Likhu is consistent with data from elsewhere in the Nepal Middle Hills, but contrasts with the very large increases in short-term erosion rates seen in agricultural catchments in other steep mountain settings. Our results suggest that the large sediment fluxes exported from the Likhu and other Middle Hills rivers in the Himalaya are derived in large part from natural processes, rather than from soil erosion as a result of agricultural activity. Because of the high natural background rates, simple comparison of short- and long-term rates may not reveal unsustainable soil degradation, particularly if much of the catchment-scale erosion flux derives from mass wasting. Correcting for the mass wasting contribution in the Likhu implies minimum catchment-averaged soil production rates of ~0.25-0.35 mm yr-1. The deficit between these production rates and soil losses suggests that terraced agriculture in the Likhu may not be associated with a large systematic soil deficit, at least when terraces are well maintained, but that poorly managed terraces, forest and scrubland may lead to rapid depletion of soil resources.

Sorption interactions of organic compounds with soils affected by agricultural olive mill wastewater.

PubMed

Keren, Yonatan; Borisover, Mikhail; Bukhanovsky, Nadezhda

2015-11-01

The organic compound-soil interactions may be strongly influenced by changes in soil organic matter (OM) which affects the environmental fate of multiple organic pollutants. The soil OM changes may be caused by land disposal of various OM-containing wastes. One unique type of OM-rich waste is olive mill-related wastewater (OMW) characterized by high levels of OM, the presence of fatty aliphatics and polyphenolic aromatics. The systematic data on effects of the land-applied OMW on organic compound-soil interactions is lacking. Therefore, aqueous sorption of simazine and diuron, two herbicides, was examined in batch experiments onto three soils, including untreated and OMW-affected samples. Typically, the organic compound-soil interactions increased following the prior land application of OMW. This increase is associated with the changes in sorption mechanisms and cannot be attributed solely to the increase in soil organic carbon content. A novel observation is that the OMW application changes the soil-sorbent matrix in such a way that the solute uptake may become cooperative or the existing ability of a soil sorbent to cooperatively sorb organic molecules from water may become characterized by a larger affinity. The remarkable finding of this study was that in some cases a cooperative uptake of organic molecules by soils makes itself evident in distinct sigmoidal sorption isotherms rarely observed in soil sorption of non-ionized organic compounds; the cooperative herbicide-soil interactions may be characterized by the Hill model coefficients. However, no single trend was found for the effect of applied OMW on the mechanisms of organic compound-soil interactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Flooding event impacts soil pH, Ca, and P concentration distribution in a cattle backgrounding site on karst topography.

USDA-ARS?s Scientific Manuscript database

Beef cattle backgrounding in US, function as an intermediate between cow-calf enterprises and feedlot finishing. Beef cattle backgrounding receives weaned calves of different growth stages from cow-calf operations and prepare them ready for feed lot finishing. Many beef cattle backgrounding operati...

Evaluating the effects of triclosan on 3 field crops grown in 4 formulations of biosolids.

PubMed

Shahmohamadloo, René S; Lissemore, Linda; Prosser, Ryan S; Sibley, Paul K

2017-07-01

A growing body of evidence suggests that amending soil with biosolids can be an integral component of sustainable agriculture. Despite strong evidence supporting its beneficial use in agriculture, there are concerns that chemicals, such as pharmaceuticals and personal care products, could present a risk to terrestrial ecosystems and human health. Triclosan is one of the most commonly detected compounds in biosolids. To date, laboratory studies indicate that triclosan likely poses a de minimis risk to field crops; however, these studies were either conducted under unrealistic exposure conditions or only assessed 1 or 2 formulations of biosolids. The purpose of the present study was to characterize the effects of triclosan on field crops in soils amended with 4 different formulations of biosolids (liquid, dewatered, compost, and alkaline-hydrolyzed), containing both background and spiked triclosan concentrations, following best management practices used in the province of Ontario. Three crop species (corn, soybean, and spring wheat) were evaluated using several plant growth endpoints (e.g., root wet mass, shoot length, shoot wet/dry mass) in 70-d to 90-d potted soil tests. The results indicated no adverse impact of triclosan on any crop-biosolids combination. Conversely, amending soil with biosolids either enhanced or had no negative effect, on the growth of plants. Results of the present study suggest little risk of triclosan to crops in agricultural fields amended with biosolids. Environ Toxicol Chem 2017;36:1896-1908. © 2016 SETAC. © 2016 SETAC.

Spatial Dependence of Physical Attributes and Mechanical Properties of Ultisol in a Sugarcane Field.

PubMed

Tavares, Uilka Elisa; Rolim, Mário Monteiro; de Oliveira, Veronildo Souza; Pedrosa, Elvira Maria Regis; Siqueira, Glécio Machado; Magalhães, Adriana Guedes

2015-01-01

This study investigates the effect of conventional tillage and application of the monoculture of sugar cane on soil health. Variables like density, moisture, texture, consistency limits, and preconsolidation stress were taken as indicators of soil quality. The measurements were made at a 120 × 120 m field cropped with sugar cane under conventional tillage. The objective of this work was to characterize the soil and to study the spatial dependence of the physical and mechanical attributes. Then, undisturbed soil samples were collected to measure bulk density, moisture content and preconsolidation stress and disturbed soil samples for classification of soil texture, and consistency limits. The soil texture indicated that soil can be characterized as sandy clay soil and a sandy clay loam soil, and the consistency limits indicated that the soil presents an inorganic low plasticity clay. The preconsolidation tests tillage in soil moisture content around 19% should be avoided or should be chosen a management of soil with lighter vehicles in this moisture content, to avoid risk of compaction. Using geostatistical techniques mapping was possible to identify areas of greatest conservation soil and greater disturbance of the ground.

Spatial Dependence of Physical Attributes and Mechanical Properties of Ultisol in a Sugarcane Field

PubMed Central

Tavares, Uilka Elisa; Monteiro Rolim, Mário; Souza de Oliveira, Veronildo; Maria Regis Pedrosa, Elvira; Siqueira, Glécio Machado; Guedes Magalhães, Adriana

2015-01-01

This study investigates the effect of conventional tillage and application of the monoculture of sugar cane on soil health. Variables like density, moisture, texture, consistency limits, and preconsolidation stress were taken as indicators of soil quality. The measurements were made at a 120 × 120 m field cropped with sugar cane under conventional tillage. The objective of this work was to characterize the soil and to study the spatial dependence of the physical and mechanical attributes. Then, undisturbed soil samples were collected to measure bulk density, moisture content and preconsolidation stress and disturbed soil samples for classification of soil texture, and consistency limits. The soil texture indicated that soil can be characterized as sandy clay soil and a sandy clay loam soil, and the consistency limits indicated that the soil presents an inorganic low plasticity clay. The preconsolidation tests tillage in soil moisture content around 19% should be avoided or should be chosen a management of soil with lighter vehicles in this moisture content, to avoid risk of compaction. Using geostatistical techniques mapping was possible to identify areas of greatest conservation soil and greater disturbance of the ground. PMID:26167528

Root adaptations to soils with low fertility and aluminium toxicity

PubMed Central

Rao, Idupulapati M.; Miles, John W.; Beebe, Stephen E.; Horst, Walter J.

2016-01-01

Background Plants depend on their root systems to acquire the water and nutrients necessary for their survival in nature, and for their yield and nutritional quality in agriculture. Root systems are complex and a variety of root phenes have been identified as contributors to adaptation to soils with low fertility and aluminium (Al) toxicity. Phenotypic characterization of root adaptations to infertile soils is enabling plant breeders to develop improved cultivars that not only yield more, but also contribute to yield stability and nutritional security in the face of climate variability. Scope In this review the adaptive responses of root systems to soils with low fertility and Al toxicity are described. After a brief introduction, the purpose and focus of the review are outlined. This is followed by a description of the adaptive responses of roots to low supply of mineral nutrients [with an emphasis on low availability of nitrogen (N) and phosphorus (P) and on toxic levels of Al]. We describe progress in developing germplasm adapted to soils with low fertility or Al toxicity using selected examples from ongoing breeding programmes on food (maize, common bean) and forage/feed (Brachiaria spp.) crops. A number of root architectural, morphological, anatomical and metabolic phenes contribute to the superior performance and yield on soils with low fertility and Al toxicity. Major advances have been made in identifying root phenes in improving adaptation to low N (maize), low P (common bean) or high Al [maize, common bean, species and hybrids of brachiariagrass, bulbous canarygrass (Phalaris aquatica) and lucerne (Medicago sativa)]. Conclusions Advanced root phenotyping tools will allow dissection of root responses into specific root phenes that will aid both conventional and molecular breeders to develop superior cultivars. These new cultivars will play a key role in sustainable intensification of crop–livestock systems, particularly in smallholder systems of the tropics. Development of these new cultivars adapted to soils with low fertility and Al toxicity is needed to improve global food and nutritional security and environmental sustainability. PMID:27255099

Short-chain chlorinated paraffins (SCCPs) in surface soil from a background area in China: occurrence, distribution, and congener profiles.

PubMed

Wang, Xue-Tong; Zhang, Yuan; Miao, Yi; Ma, Ling-Ling; Li, Yuan-Cheng; Chang, Yue-Ya; Wu, Ming-Hong

2013-07-01

Short-chain chlorinated paraffins (SCCPs) are extremely complex technical mixtures of polychlorinated n-alkanes with carbon chain lengths from C10 to C13 and chlorine content between 49 and 70%. SCCPs are under consideration for inclusion in the Stockholm Convention on persistent organic pollutants. SCCPs have been used extensively in industrial production, but little is known about the pollution level in soil environment in China. In this study, levels and distribution of SCCPs in soil samples from Chongming Island were analyzed. Concentrations of total SCCPs in soil samples ranged from 0.42 to 420 ng g(-1), with a median of 9.6 ng g(-1). The ubiquitous occurrence of SCCPs in Chongming Island implied that long-range atmospheric transport and soil-air exchange may be the most important pathways for SCCP contamination in the background area. The localized SCCP contamination could be derived from an unidentified source. Hierarchical cluster analysis indicated that C13- and C11-congeners were predominant in most soils and C10- and C12-congeners dominated in the remaining soils. Cl7- and Cl8-congeners were on the average the most dominant chlorine congeners in nearly all soils. Principal component analysis suggested that the separation of even and odd carbon chain congeners occurred during long-range atmospheric transport and aging in soil in the study area.

Metagenomic Characterization and Biochemical Analysis of Cellulose-Degrading Bacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant Materials, and Soil

DTIC Science & Technology

2016-01-04

Biochemical Analysis of Cellulose-DegradingBacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant Materials,and Soil In an effort to...degrading bacteria from various samples, including termite gut, sheep rumen, soil, and decaying plant materials. Using selective media culture with...Metagenomic Characterization and Biochemical Analysis of Cellulose-DegradingBacterial Communities from Sheep Rumen, Termite Hindgut, Decaying Plant

CHARACTERIZING SOILS FOR HAZAROUDS WASTE SITE ASSESSMENTS

EPA Science Inventory

The purpose of this paper is to provide guidance to Remedial Project Managers (RPM) and On-Scene Coordinators (OSC) concerning soil characterization data types required for decision-making in the CERCLA RI/FS process related to risk assessment and remedial alternative evaluation ...

Measurement of DDT fluxes from a historically treated agricultural soil in Canada.

PubMed

Kurt-Karakus, Perihan Binnur; Bidleman, Terry F; Staebler, Ralf M; Jones, Kevin C

2006-08-01

Organocohlorine pesticide (OCP) residues in agricultural soils are of concern due to the uptake of these compounds by crops, accumulation in the foodchain, and reemission from soils to the atmosphere. Although it has been about three decades since DDT was banned for agricultural uses in Canada, residues persist in soils of some agricultural areas. Emission of DDT compounds to the atmosphere from a historically treated field in southern Ontario was determined in fall 2004 and spring 2005. The sigmaDDTs concentration in the high organic matter (71%) soil was 19 +/- 4 microg g(-1) dry weight. Concentration gradients in the air were measured at 5, 20, 72, and 200 cm above soil using glass fiber filter-polyurethane foam cartridges. Air concentrations of sigmaDDTs averaged 5.7 +/- 5.1 ng m(-3) at 5 cm and decreased to 1.3 +/- 0.8 ng m(-3) at 200 cm and were 60-300 times higher than levels measured at a background site 30 km away. Soil-air fugacity fractions, fs/(fs + fa), of p,p'-DDE, p,p'-DDD, and p,p'-DDT ranged from 0.42 to 0.91 using air concentrations measured above the soil and > or = 0.99 using background air concentrations, indicating that the soil was a net source to the background air. Fractionation of DDT compounds during volatilization was predicted using either liquid-phase vapor pressures (PL) or octanol-air partition coefficients (KOA). Relative emissions of p,p'-DDE and p,p'-DDT were better described by PL than KOA, whereas either PL or KOA successfully accounted for the fractionation of p,p'-DDT and o,p'-DDT. Soil-to-air fluxes were calculated from air concentration gradients and turbulent exchange coefficients determined from micrometeorological measurements. Average fluxes of sigmaDDTs were 90 +/- 24 ng m(-2) h(-1) in fall and 660 +/- 370 ng m(-2) h(-1) in spring. Higher soil temperatures in spring accounted for the higher fluxes. A volatilization half-life of approximately 200 y was estimated for sigmaDDT in the upper 5 cm of the soil column, assuming the average flux rate for 12 h d-(1) over 8 months of the year. Thus, in the absence of other dissipation processes, the soil will continue to be a source of atmospheric contamination for a very long time.

Characterization of soils from an industrial complex contaminated with elemental mercury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Carrie L; Watson, David B; Liang, Liyuan

2013-01-01

Historic use of liquid elemental mercury (Hg(0)l) at the Y-12 National Security Complex in Oak Ridge, TN, USA resulted in large deposits of Hg(0)l in the soils. An evaluation of analytical tools for characterizing the speciation of Hg in the soils at the Y-12 facility was conducted and these tequniques were used to examine the speciation of Hg in two soil cores collect at the site. These include X-ray fluorescence (XRF), soil Hg(0) headspace analysis, and total Hg determination by acid digestion coupled with cold vapor atomic absorption. Hg concentrations determined using XRF, a tool that has been suggestions formore » quick onsite characterization of soils, were lower than concentrations determined by HgT analysis and as a result this technique is not suitable for the evaluation of Hg concentrations in heterogeneous soils containing Hg(0)l. Hg(0)g headspace analysis can be used to examine the presence of Hg(0)l in soils and when coupled with HgT analysis an understanding of the speciation of Hg in soils can be obtained. Two soil cores collected within the Y-12 complex highlight the heterogeneity in the depth and extent of Hg contamination, with Hg concentrations ranging from 0.05 to 8400 mg/kg. At one location Hg(0)l was distributed throughout 3.2 meters of core whereas the core from a location only 12 meters away only contained Hg(0)l in 0.3 m zone of the core. Sequential extractions, used to examine the forms of Hg in the soils, indicated that at depths within the core that have low Hg concentrations organically associated Hg is dominant. Soil from the zone of groundwater inundation showed reduced characteristics and the Hg is likely present as Hg-sulfide species. At this location it appears that Hg transported within the groundwater is a source of Hg to the soil. Overall the characterization of Hg in soils containing Hg(0) l is difficult due to the heterogeneous distribution within the soils and this challenge is enhanced in industrial facilities in which fill material comprise most of the soils and historical and continuing reworking of the subsurface has remobilized the Hg.« less

Spectroscopic characterization and evaluation of SOM in areas under different soil tillage systems

USDA-ARS?s Scientific Manuscript database

Agricultural management influences the amount of carbon returned to the soil in the form of plant residues and animal manures and the rate of decomposition of soil carbon. The physical and chemical characteristics of soil carbon influence its recalcitrance to decomposition. We sampled soil from th...

Evaluating the effect of tillage on soil structural properties using the pedostructure concept

USDA-ARS?s Scientific Manuscript database

The pedostructure (PS) concept is a physically-based method of soil characterization that defines a soil based on its structure and the relationship between structure and soil water behavior. There are fifteen unique pedostructure parameters that define the macropore and micropore soil water behavio...

Characterization of Soil Samples of Enzyme Activity

ERIC Educational Resources Information Center

Freeland, P. W.

1977-01-01

Described are nine enzyme essays for distinguishing soil samples. Colorimetric methods are used to compare enzyme levels in soils from different sites. Each soil tested had its own spectrum of activity. Attention is drawn to applications of this technique in forensic science and in studies of soil fertility. (Author/AJ)

Kim Magrini | NREL

Science.gov Websites

Developing char-based soil amendments Soil carbon and char analysis via molecular beam mass spectrometry depth profiling, Fourier transform infrared [FTIR]) Rapid soil carbon analysis using analytical DRIFTS, 13C NMR, and py-MBMS to Characterize the Effects of Soil Science Oxidation Assays on Soil Organic

REGIONAL SOIL WATER RETENTION IN THE CONTIGUOUS US: SOURCES OF VARIABILITY AND VOLCANIC SOIL EFFECTS

EPA Science Inventory

Water retention of mineral soil is often well predicted using algorithms (pedotransfer functions) with basic soil properties but the spatial variability of these properties has not been well characterized. A further source of uncertainty is that water retention by volcanic soils...

Medusahead: Available soil N and microbial communities in native and invasive soils

Treesearch

Robert R. Blank; Rene Sforza; Tye Morgan

2008-01-01

To better understand why medusahead (Taeniatherum caput-medusae) is invasive, we quantified soil N availability and characterized soil microbial communities between native and invasive populations. No consistent differences in soil N mineralization potentials were noted between native medusahead sites in Spain, Turkey, France, and Greece and two...

Evaluation and characterization of anti-estrogenic and anti-androgenic activities in soil samples along the Second Songhua River, China.

PubMed

Li, Jian; Wang, Yafei; Kong, Dongdong; Wang, Jinsheng; Teng, Yanguo; Li, Na

2015-11-01

In the present study, re-combined estrogen receptor (ER) and androgen receptor (AR) gene yeast assays combined with a novel approach based on Monte Carlo simulation were used for evaluation and characterization of soil samples collected from Jilin along the Second Songhua River to assess their antagonist/agonist properties for ER and AR. The results showed that estrogenic activity only occurred in the soil samples collected in the agriculture area, but most soil samples showed anti-estrogenic activities, and the bioassay-derived 4-hydroxytamoxifen equivalents ranged from N.D. to 23.51 μg/g. Hydrophilic substance fractions were determined as potential contributors associated with anti-estrogenic activity in these soil samples. Moreover, none of the soil samples exhibited AR agonistic potency, whereas 54% of the soil samples exhibited AR antagonistic potency. The flutamide equivalents varied between N.D. and 178.05 μg/g. Based on Monte Carlo simulation-related mass balance analysis, the AR antagonistic activities were significantly correlated with the media polar and polar fractions. All of these results support that this novel calculation method can be adopted effectively to quantify and characterize the ER/AR agonists and antagonists of the soil samples, and these data could help provide useful information for future management and remediation efforts.

Soil carbon storage estimation in a forested watershed using quantitative soil-landscape modeling

Treesearch

James A. Thompson; Randall K. Kolka

2005-01-01

Carbon storage in soils is important to forest ecosystems. Moreover, forest soils may serve as important C sinks for ameliorating excess atmospheric CO2. Spatial estimates of soil organic C (SOC) storage have traditionally relied upon soil survey maps and laboratory characterization data. This approach does not account for inherent variability...

Converging patterns of uptake and hydraulic redistribution of soil water in contrasting woody vegetation types.

Treesearch

F.C. Meinzer; J.R. Brooks; S. Bucci; G. Goldstein; F.G. Scholz; J.M. Arren

2004-01-01

We used concurrent measurements of soil water content and soil water potential (Ψsoil) to assess the effects of Ψsoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles at six sites characterized by differences in the types and amounts of woody vegetations and...

Degradation of soil fertility can cancel pollination benefits in sunflower.

PubMed

Tamburini, Giovanni; Berti, Antonio; Morari, Francesco; Marini, Lorenzo

2016-02-01

Pollination and soil fertility are important ecosystem services to agriculture but their relative roles and potential interactions are poorly understood. We explored the combined effects of pollination and soil fertility in sunflower using soils from a trial characterized by different long-term input management in order to recreate plausible levels of soil fertility. Pollinator exclusion was used as a proxy for a highly eroded pollination service. Pollination benefits to yield depended on soil fertility, i.e., insect pollination enhanced seed set and yield only under higher soil fertility indicating that limited nutrient availability may constrain pollination benefits. Our study provides evidence for interactions between above- and belowground ecosystem services, highlighting the crucial role of soil fertility in supporting agricultural production not only directly, but also indirectly through pollination. Management strategies aimed at enhancing pollination services might fail in increasing yield in landscapes characterized by high soil service degradation. Comprehensive knowledge about service interactions is therefore essential for the correct management of ecosystem services in agricultural landscapes.

78 FR 33276 - National Oil and Hazardous Substances Pollution Contingency Plan; National Priorities List...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-04

... deletion pertains to soils, dust and deteriorating lead-based paint, where applicable, of the 1,154... residential parcels and associated soil, dust and deteriorating lead- based paint will remain on the NPL and... Background and History The Omaha Lead Site (OLS or Site [CERCLIS ID NESFN0703481]) includes surface soils...

Landscape soil variability in relatively static and dynamic properties in arid and semi-arid ecosystems: do they matter for restoration?

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Soils matter for restoration. Or do they? This paper takes a process-based approach to this question, using a combination of published literature, pedotransfer functions, and several datasets where a range of relatively static and dynamic soil properties were measured on...

Ground-water and soil contamination near two pesticide-burial sites in Minnesota

USGS Publications Warehouse

Stark, J.R.; Strudell, J.D.; Bloomgren, P.A.; Eger, P.

1987-01-01

In general, concentrations of lead and arsenic in soil and groundwater were below background concentrations for the areas. Concentrations of organic pesticides generally were below analytical-detection limits. The limited solubility of the chemicals and the tendency of the contaminants to be sorbed on soil particles probably combined to restrict mobilization of the chemicals.

Effects of CO2 dissolution on phase distribution and degradation of dimethyl disulfide in soils under grape production

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Dimethyl disulfide (DMDS) is a fumigant recently registered in parts of U.S. The fumigant has high pesticidal activity, but lower volatility compared to other fumigants, leading to less soil dispersion. This study assessed the use of CO2 as a propellant to improve soil dispersion and dif...

Dynaflow User’s Guide

DTIC Science & Technology

1988-11-01

264 ANALYSIS RESTART. ............. ..... ....... 269 1.0 TITLE CARD. .............. ............. 271 2.0 CONTROL CARDS...stress soil model will provide a tool for such analysis of waterfront structures. To understand the significance of liquefaction, it is important to note...Implementing this effective stress soil model into a finite element computer program would allow analysis of soil and structure together. TECHNICAL BACKGROUND

Organic compounds in the particulate matter from burning organic soils

Treesearch

Charles K. McMahon; Jerry D. White; Skevos N. Tsoukalas

1985-01-01

This paper is directed to people interested in the environmental impact of natural emissions. Natural emissions are common and contribute significantly to tropospheric background levels. Several million hectares of the United States are covered by organic soils. During droughts, these soils can ignite and support slow combustion which often persists for weeks causing...

Theoretical Relationships between Luminescence and Hillslope Soil Vertical Diffusivity: a Numerical Modeling Approach

NASA Astrophysics Data System (ADS)

Gray, H. J.; Tucker, G. E.; Mahan, S.

2017-12-01

Luminescence is a property of matter that can be used to obtain depositional ages from fine sand. Luminescence generates due to exposure to background ionizing radiation and is removed by sunlight exposure in a process known as bleaching. There is evidence to suggest that luminescence can also serve as a sediment tracer in fluvial and hillslope environments. For hillslope environments, it has been suggested that the magnitude of luminescence as a function of soil depth is related to the strength of soil mixing. Hillslope soils with a greater extent of mixing will have previously surficial sand grains moved to greater depths in a soil column. These previously surface-exposed grains will contain a lower luminescence than those which have never seen the surface. To attempt to connect luminescence profiles with soil mixing rate, here defined as the soil vertical diffusivity, I conduct numerical modelling of particles in hillslope soils coupled with equations describing the physics of luminescence. I use recently published equations describing the trajectories of particles under both exponential and uniform soil velocity soils profiles and modify them to include soil diffusivity. Results from the model demonstrates a strong connection between soil diffusivity and luminescence. Both the depth profiles of luminescence and the total percent of surface exposed grains will change drastically based on the magnitude of the diffusivity. This suggests that luminescence could potentially be used to infer the magnitude of soil diffusivity. However, I test other variables such as the soil production rate, e-folding length of soil velocity, background dose rate, and soil thickness, and I find these other variables can also affect the relationship between luminescence and diffusivity. This suggests that these other variables may need to be constrained prior to any inferences of soil diffusivity from luminescence measurements. Further field testing of the model in areas where the soil vertical diffusivity and other parameters are independently known will provide a test of this potential new method.

Forms of acid hydrolysis and gley formation and their role in the development of light-colored acid eluvial (Podzolic) horizons

NASA Astrophysics Data System (ADS)

Zaidel'Man, F. R.

2010-04-01

Nowadays, three processes, namely lessivage, acid hydrolysis, and gleying, are considered as responsible for the development of loamy and clayey podzolic soils. However, as was shown earlier, lessivage is not obligatory for their origin. In view of assessing the reasons for the formation of light-colored acid eluvial horizons, this article deals with the role of acid hydrolysis under aerobic conditions against the background of a percolative water regime and of two forms of gleying in the development of the horizons mentioned above. One form of gleying occurs under permanent anaerobic conditions against the background of a stagnant water regime; the other one is formed under pulsating anaerobic-aerobic conditions against the background of a stagnant-percolative water regime. As a result, three large genetically individual groups of soils are formed: nondifferentiated brown and gley, and differentiated podzolic soils on different parent rocks. The two latter forms of gleying are identical in their effects on the mineral substrates. They cause the iron removal from the soils. Among the three processes considered, the last one (gleying under a stagnant-percolative water regime) is the single reason for the leaching of most of the metals, the formation of light-colored acid eluvial horizons and their clay depletion, and for the differentiation of the soil profile.

Successive DNA extractions improve characterization of soil microbial communities

PubMed Central

de Hollander, Mattias; Smidt, Hauke; van Veen, Johannes A.

2017-01-01

Currently, characterization of soil microbial communities relies heavily on the use of molecular approaches. Independently of the approach used, soil DNA extraction is a crucial step, and success of downstream procedures will depend on how well DNA extraction was performed. Often, studies describing and comparing soil microbial communities are based on a single DNA extraction, which may not lead to a representative recovery of DNA from all organisms present in the soil. The use of successive DNA extractions might improve soil microbial characterization, but the benefit of this approach has only been limitedly studied. To determine whether successive DNA extractions of the same soil sample would lead to different observations in terms of microbial abundance and community composition, we performed three successive extractions, with two widely used commercial kits, on a range of clay and sandy soils. Successive extractions increased DNA yield considerably (1–374%), as well as total bacterial and fungal abundances in most of the soil samples. Analysis of the 16S and 18S ribosomal RNA genes using 454-pyrosequencing, revealed that microbial community composition (taxonomic groups) observed in the successive DNA extractions were similar. However, successive DNA extractions did reveal several additional microbial groups. For some soil samples, shifts in microbial community composition were observed, mainly due to shifts in relative abundance of a number of microbial groups. Our results highlight that performing successive DNA extractions optimize DNA yield, and can lead to a better picture of overall community composition. PMID:28168105

Geosynthetic Reinforced Soil Integrated Bridge System, Synthesis Report

DOT National Transportation Integrated Search

2011-01-01

This report is the second in a two-part series to provide engineers with the necessary background knowledge of Geosynthetic Reinforced Soil (GRS) technology and its fundamental characteristics as an alternative to other construction methods. It suppl...

‘Natural background’ soil water repellency in conifer forests of the north-western USA: Its prediction and relationship to wildfire occurrence

NASA Astrophysics Data System (ADS)

Doerr, S. H.; Woods, S. W.; Martin, D. A.; Casimiro, M.

2009-06-01

SummarySoils under a wide range of vegetation types exhibit water repellency following the passage of a fire. This is viewed by many as one of the main causes for accelerated post-fire runoff and soil erosion and it has often been assumed that strong soil water repellency present after wildfire is fire-induced. However, high levels of repellency have also been reported under vegetation types not affected by fire, and the question arises to what degree the water repellency observed at burnt sites actually results from fire. This study aimed at determining 'natural background' water repellency in common coniferous forest types in the north-western USA. Mature or semi-mature coniferous forest sites ( n = 81), which showed no evidence of recent fires and had at least some needle cast cover, were sampled across six states. After careful removal of litter and duff at each site, soil water repellency was examined in situ at the mineral soil surface using the Water Drop Penetration Time (WDPT) method for three sub-sites, followed by collecting near-surface mineral soil layer samples (0-3 cm depth). Following air-drying, samples were further analyzed for repellency using WDPT and contact angle ( θsl) measurements. Amongst other variables examined were dominant tree type, ground vegetation, litter and duff layer depth, slope angle and aspect, elevation, geology, and soil texture, organic carbon content and pH. 'Natural background' water repellency (WDPT > 5 s) was detected in situ and on air-dry samples at 75% of all sites examined irrespective of dominant tree species ( Pinus ponderosa, Pinus contorta, Picea engelmanii and Pseudotsuga menziesii). These findings demonstrate that the soil water repellency commonly observed in these forest types following burning is not necessarily the result of recent fire but can instead be a natural characteristic. The notion of a low background water repellency being typical for long-unburnt conifer forest soils of the north-western USA is therefore incorrect. It follows that, where pre-fire water repellency levels are not known or highly variable, post-fire soil water repellency conditions are an unreliable indicator in classifying soil burn severity. The terrain and soil variables examined showed, overall, no convincing relationship with the repellency levels observed ( R2 < 0.15) except that repellency was limited in soils (i) developed over meta-sedimentary lithology and (ii) with clay contents >4%. This suggests that water repellency levels cannot be predicted with confidence from common terrain or soil variables.

Reading the Molecular Code in Soils

NASA Astrophysics Data System (ADS)

Hess, N. J.; Tfaily, M. M.; O'Brien, S. L.; Tolic, N.; Jastrow, J. D.; Amonette, J. E.

2015-12-01

There is much that we understand about the relationship between plants, microbes, soil, and water but that understanding is incomplete at the molecular scale. With advent of high throughput genomic sequencing we are beginning to appreciate the diversity of microbial community structure and function and its response to the rhythm of plant function. Through the lens of high-resolution mass spectrometry we are getting our first glimpses of the diversity of soil and pore water organic chemistry at the molecular level. In combination, these diverse data streams are revealing traces of chemical metabolic pathways. This approach promises to reveal many exciting future discoveries, shedding light into the "black box" that exists beneath our feet. In this talk we discuss our experience with the molecular characterization of soils from native prairie to restored prairie to active corn-soybean soils from the DOE funded CSiTE project in Batavia, Illinois. We focus on how common soil separation and fractionation techniques can affect the resulting molecular soil characterization by comparing whole soils to those that have been fractionated into micro- and macro-aggregates and their corresponding silt and clay fractions. When carefully utilized and interpreted these fractionation techniques can be utilized for deepening understanding of the biotic and abiotic chemical pathways effecting the organic chemistry in the different soil fractions. In highly fractionated soils we find significant differences in organic chemistry between silt and clay separates of corresponding hierarchical aggregate fractions. However the most biologically rich information resides in the whole soil. Here we see significant gradients in soil chemistry across to active agricultural to restored to native prairie soils. These results suggest a cautionary note, namely that soil fractionation prior to molecular characterization can reveal much about the "abiotic" interactions between organic molecules and soil minerals but the much of the "biotic" story resides in the whole soil.

Baseline geochemistry of soil and bedrock Tshirege Member of the Bandelier Tuff at MDA-P

DOE Office of Scientific and Technical Information (OSTI.GOV)

Warren, R.G.; McDonald, E.V.; Ryti, R.T.

1997-08-01

This report provides baseline geochemistry for soils (including fill), and for bedrock within three specific areas that are planned for use in the remediation of Material Disposal Area P (MDA-P) at Technical Area 16 (TA-16). The baseline chemistry includes leachable element concentrations for both soils and bedrock and total element concentrations for all soil samples and for two selected bedrock samples. MDA-P operated from the early 1950s to 1984 as a landfill for rubble and debris generated by the burning of high explosives (HE) at the TA-16 Burning Ground, HE-contaminated equipment and material, barium nitrate sand, building materials, and trash.more » The aim of this report is to establish causes for recognizable chemical differences between the background and baseline data sets. In many cases, the authors conclude that recognizable differences represent natural enrichments. In other cases, differences are best attributed to analytical problems. But most importantly, the comparison of background and baseline geochemistry demonstrates significant contamination for several elements not only at the two remedial sites near the TA-16 Burning Ground, but also within the entire region of the background study. This contamination is highly localized very near to the surface in soil and fill, and probably also in bedrock; consequently, upper tolerance limits (UTLs) calculated as upper 95% confidence limits of the 95th percentile are of little value and thus are not provided. This report instead provides basic statistical summaries and graphical comparisons for background and baseline samples to guide strategies for remediation of the three sites to be used in the restoration of MDA-P.« less

Microbial diversity in hummock and hollow soils of three wetlands on the Qinghai-Tibetan Plateau revealed by 16S rRNA pyrosequencing.

PubMed

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world's highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1-10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem.

Microbial Diversity in Hummock and Hollow Soils of Three Wetlands on the Qinghai-Tibetan Plateau Revealed by 16S rRNA Pyrosequencing

PubMed Central

Deng, Yongcui; Cui, Xiaoyong; Hernández, Marcela; Dumont, Marc G.

2014-01-01

The wetlands of the Qinghai-Tibetan Plateau are believed to play an important role in global nutrient cycling, but the composition and diversity of microorganisms in this ecosystem are poorly characterized. An understanding of the effects of geography and microtopography on microbial populations will provide clues to the underlying mechanisms that structure microbial communities. In this study, we used pyrosequencing-based analysis of 16S rRNA gene sequences to assess and compare the composition of soil microbial communities present in hummock and hollow soils from three wetlands (Dangxiong, Hongyuan and Maduo) on the Qinghai-Tibetan Plateau, the world’s highest plateau. A total of 36 bacterial phyla were detected. Proteobacteria (34.5% average relative abundance), Actinobacteria (17.3%) and Bacteroidetes (11%) had the highest relative abundances across all sites. Chloroflexi, Acidobacteria, Verrucomicrobia, Firmicutes, and Planctomycetes were also relatively abundant (1–10%). In addition, archaeal sequences belonging to Euryarchaea, Crenarchaea and Thaumarchaea were detected. Alphaproteobacteria sequences, especially of the order Rhodospirillales, were significantly more abundant in Maduo than Hongyuan and Dangxiong wetlands. Compared with Hongyuan soils, Dangxiong and Maduo had significantly higher relative abundances of Gammaproteobacteria sequences (mainly order Xanthomonadales). Hongyuan wetland had a relatively high abundance of methanogens (mainly genera Methanobacterium, Methanosarcina and Methanosaeta) and methanotrophs (mainly Methylocystis) compared with the other two wetlands. Principal coordinate analysis (PCoA) indicated that the microbial community structure differed between locations and microtopographies and canonical correspondence analysis indicated an association between microbial community structure and soil properties or geography. These insights into the microbial community structure and the main controlling factors in wetlands of the Qinghai-Tibetan Plateau provide a valuable background for further studies on biogeochemical processes in this distinct ecosystem. PMID:25078273

Atmospheric dispersion of natural carbon dioxide emissions on Vulcano Island, Italy

NASA Astrophysics Data System (ADS)

Granieri, D.; Carapezza, M. L.; Barberi, F.; Ranaldi, M.; Ricci, T.; Tarchini, L.

2014-07-01

La Fossa quiescent volcano and its surrounding area on the Island of Vulcano (Italy) are characterized by intensive, persistent degassing through both fumaroles and diffuse soil emissions. Periodic degassing crises occur, with marked increase in temperature and steam and gas output (mostly CO2) from crater fumaroles and in CO2 soil diffuse emission from the crater area as well as from the volcano flanks and base. The gas hazard of the most inhabited part of the island, Vulcano Porto, was investigated by simulating the CO2 dispersion in the atmosphere under different wind conditions. The DISGAS (DISpersion of GAS) code, an Eulerian model based on advection-diffusion equations, was used together with the mass-consistent Diagnostic Wind Model. Numerical simulations were validated by measurements of air CO2 concentration inside the village and along the crater's rim by means of a Soil CO2 Automatic Station and a Tunable Diode Laser device. The results show that in the village of Vulcano Porto, the CO2 air concentration is mostly due to local soil degassing, while the contribution from the crater gas emission is negligible at the breathing height for humans and always remains well below the lowest indoor CO2 concentration threshold recommended by the health authorities (1000 ppm). Outdoor excess CO2 maxima up to 200 ppm above local background CO2 air concentration are estimated in the center of the village and up to 100 ppm in other zones. However, in some ground excavations or in basements the health code threshold can be exceeded. In the crater area, because of the combined effect of fumaroles and diffuse soil emissions, CO2 air concentrations can reach 5000-7000 ppm in low-wind conditions and pose a health hazard for visitors.

AIS spectra of desert shrub canopies

NASA Technical Reports Server (NTRS)

Murray, R.; Isaacson, D. L.; Schrumpf, B. J.; Ripple, W. J.; Lewis, A. J.

1986-01-01

Airborne Imaging Spectrometer (AIS) data were collected 30 August 1985 from a desert shrub community in central Oregon. Spectra from artificial targets placed on the test site and from bare soil, big sagebrush (Artemesia tridentata wyomingensis), silver sagebrush (Artemesia cana bolander), and exposed volcanic rocks were studied. Spectral data from grating position 3 (tree mode) were selected from 25 ground positions for analysis by Principal Factor Analysis (PFA). In this grating position, as many as six factors were identified as significant in contributing to spectral structure. Channels 74 through 84 (tree mode) best characterized between-class differences. Other channels were identified as nondiscriminating and as associated with such errors as excessive atmospheric absorption and grating positin changes. The test site was relatively simple with the two species (A. tridentata and A. cana) representing nearly 95% of biomass and with only two mineral backgrounds, a montmorillonitic soil and volcanic rocks. If, as in this study, six factors of spectral structure can be extracted from a single grating position from data acquired over a simple vegetation community, then AIS data must be considered rich in information-gathering potential.

Sample sizes to control error estimates in determining soil bulk density in California forest soils

Treesearch

Youzhi Han; Jianwei Zhang; Kim G. Mattson; Weidong Zhang; Thomas A. Weber

2016-01-01

Characterizing forest soil properties with high variability is challenging, sometimes requiring large numbers of soil samples. Soil bulk density is a standard variable needed along with element concentrations to calculate nutrient pools. This study aimed to determine the optimal sample size, the number of observation (n), for predicting the soil bulk density with a...

Site and soil characterization of hazardous waste sites using an expert system guide

NASA Astrophysics Data System (ADS)

Cameron, Roy E.

1993-03-01

An expert system guide (knowledge book) has been devised to assist field personnel who must identify, describe, sample, and interpret size and soil characteristics of hazardous waste sites. The guide takes an approach that will be unfamiliar to most soil and environmental scientists and is directed to on-scene coordinators and project managers and others who may have little soil science training. It meets the need of the U.S. Environmental Protection Agency for standard procedures, guidelines, or protocols that address soil and site contamination, particularly heavy metals. The guide is organized to include: (1) general considerations and processes for collecting and using site and soils data, (2) detailed knowledge frames (descriptive profiles) of likely site and soil conditions, (3) a citation of references, (4) an appendix listing common sources of characterization data, and (5) a glossary of more than 900 general definitions.

Effects of near soil surface characteristics on soil detachment by overland flow in a natural succession grassland

USDA-ARS?s Scientific Manuscript database

Vegetation restoration probably has great effects on the process of soil detachment. This study was conducted to investigate the effects of near soil surface characteristics on soil detachment by overland flow in a 7-year naturally restored grassland. Four treatments were designed to characterize th...

A multi-scale ''soil water structure'' model based on the pedostructure concept

NASA Astrophysics Data System (ADS)

Braudeau, E.; Mohtar, R. H.; El Ghezal, N.; Crayol, M.; Salahat, M.; Martin, P.

2009-02-01

Current soil water models do not take into account the internal organization of the soil medium and, a fortiori, the physical interaction between the water film surrounding the solid particles of the soil structure, and the surface charges of this structure. In that sense they empirically deal with the physical soil properties that are all generated from this soil water-structure interaction. As a result, the thermodynamic state of the soil water medium, which constitutes the local physical conditions, namely the pedo-climate, for biological and geo-chemical processes in soil, is not defined in these models. The omission of soil structure from soil characterization and modeling does not allow for coupling disciplinary models for these processes with soil water models. This article presents a soil water structure model, Kamel®, which was developed based on a new paradigm in soil physics where the hierarchical soil structure is taken into account allowing for defining its thermodynamic properties. After a review of soil physics principles which forms the basis of the paradigm, we describe the basic relationships and functionality of the model. Kamel® runs with a set of 15 soil input parameters, the pedohydral parameters, which are parameters of the physically-based equations of four soil characteristic curves that can be measured in the laboratory. For cases where some of these parameters are not available, we show how to estimate these parameters from commonly available soil information using published pedotransfer functions. A published field experimental study on the dynamics of the soil moisture profile following a pounded infiltration rainfall event was used as an example to demonstrate soil characterization and Kamel® simulations. The simulated soil moisture profile for a period of 60 days showed very good agreement with experimental field data. Simulations using input data calculated from soil texture and pedotransfer functions were also generated and compared to simulations of the more ideal characterization. The later comparison illustrates how Kamel® can be used and adapt to any case of soil data availability. As physically based model on soil structure, it may be used as a standard reference to evaluate other soil-water models and also pedotransfer functions at a given location or agronomical situation.

Characterization and analysis of pasture degradation in Rondonia using remote sensing

NASA Astrophysics Data System (ADS)

Numata, Izaya

2006-04-01

Although pasture degradation has been a regional concern in Amazonian ecosystems, our ability to characterize and monitor pasture degradation under different environmental and human-related conditions is still limited. This dissertation evaluated pasture degradation as it varied due to environmental and human factors across different scales by combining field measures, ancillary data, and remote sensing. To better understand the link between pasture nutrients and soil chemistry, samples were analyzed in the laboratory demonstrating that pasture soil fertility and grass nutrients varied significantly according to soil order. Pastures established on Alfisols, nutrient-rich soils, had higher levels of Phosphorus in soil and grass compared to pastures established on Oxisols and Ultisols. To evaluate remote sensing measures of pasture biophysical properties related to pasture degradation, remote sensing analysis focused on a variety of sensors that provide a range in spatial, spectral and temporal scales, including Landsat Thematic Mapper (TM), a field spectrometer, Hyperion, and the Moderate Resolution Imaging Spectroradiometer (MODIS). Of the measures derived from Landsat, degraded pastures were best characterized by high non-photosynthetic vegetation (NPV) and low shade fractions, while pastures with high biomass were characterized by high green vegetation and low NPV fractions. Absorption features calculated from hyperspectral spectra collected in the field, including water and ligno-cellulose absorption depth and area, provided the best estimates of field grass measures. Temporal MODIS Normalized Difference Vegetation Index (NDVI) data were used to characterize changes in pasture quality across the region and through time. Degraded pastures were characterized by low temporal NDVI variation and occurred in dry or very wet climate conditions and on nutrient poor soils. Productive pastures were characterized by high temporal NDVI variation, were predominantly found more in the central part of the state, and were located in areas with milder climate conditions and relatively more fertile soils. As a general trend of regional pasture change in Rondonia, the proportions of productive pastures decreased and degraded pastures increased as pastures aged. The results obtained in this dissertation will contribute to understanding pasture sustainability needs for the future of Rondonia and provide the first step in monitoring pasture degradation in the Amazon using remote sensing.

Mineralogical and Chemical Characterization of Lunar Highland Soils: Insights into the Space Weathering of Soils on Airless Bodies

NASA Technical Reports Server (NTRS)

Taylor, Lawrence A.; Patchen, Allan; Taylor, Dong-Hwa S.; Pieters, Carle; Morris, Richard V.; Keller, Lindsay P.; McKay, David S.

2010-01-01

With reflectance spectroscopy, one is measuring only properties of the fine-grained regolith, most affected by space weathering. The Lunar Soil Characterization Consortium has undertaken the task of coordinated characterization of lunar soils, with respect to their mineralogical and chemical makeup. It is these lunar soils that are being used as "ground-truth" for all air30 less bodies. Modal abundances and chemistries of minerals and glasses in the finest size fractions (20-45, 10-20, and <10 microns) of four Apollo 14 and six Apollo 16 highland soils have been determined, as well as their bulk chemistry and IS/FeO values. Bi-directional reflectance measurements (0.3-2.6 microns) of all samples were performed in the RELAB. A significant fraction of nanophase Fe(sup 0) (np-Fe(sup 0)) appears to reside in agglutinitic glasses. However, as grain size of a soil decreases, the percentage of total iron present as np-Fe0 increases significantly, whereas the agglutinitic glass content rises only slightly; this is evidence for a large contribution to the IS/FeO values from the surface-correlated nanophase Fe(sup 0), particularly in the <10 micron size fraction. The compositions of the agglutinitic glasses in these fine fractions of the highland soils are different from the bulk-chemistry of that size; however, compositional trends of the glasses are not the same as those observed for mare soils. It is apparent that the glasses in the highland soils contain chemical components from outside their terrains. It is proposed that the Apollo 16 soils have been adulterated by the addition of impact-transported soil components from surrounding maria.

Carbon availability structures microbial community composition and function in soil aggregate fractions

NASA Astrophysics Data System (ADS)

Hofmockel, K. S.; Bach, E.; Williams, R.; Howe, A.

2014-12-01

Identifying the microbial metabolic pathways that most strongly influence ecosystem carbon (C) cycling requires a deeper understanding of the availability and accessibility of microbial substrates. A first step towards this goal is characterizing the relationships between microbial community function and soil C chemistry in a field context. For this perspective, soil aggregate fractions can be used as model systems that scale between microbe-substrate interactions and ecosystem C cycling and storage. The present study addresses how physicochemical variation among soil aggregate fractions influences the composition and functional potential of C cycling microbial communities. We report variation across soil aggregates using plot scale biological replicates from biofuel agroecosystems (fertilized, reconstructed, tallgrass prairie). Our results suggest that C and nitrogen (N) chemistry significantly differ among aggregate fractions. This leads to variation in microbial community composition, which was better characterized among aggregates than by using the whole soil. In fact by considering soil aggregation, we were able to characterize almost 2000 more taxa than whole soil alone, resulting in 65% greater community richness. Availability of C and N strongly influenced the composition of microbial communities among soil aggregate fractions. The normalized abundance of microbial functional guilds among aggregate fractions correlated with C and N chemistry, as did functional potential, measured by extracellular enzyme activity. Metagenomic results suggest that soil aggregate fractions select for functionally distinct microbial communities, which may significantly influence decomposition and soil C storage. Our study provides support for the premise that integration of soil aggregate chemistry, especially microaggregates that have greater microbial richness and occur at spatial scales relevant to microbial community functioning, may be necessary to understand the role of microbial communities on terrestrial C and N cycling.

Following The Money: Characterizing the Dynamics of Microbial Ecosystems and Labile Organic Matter in Grassland Soils

NASA Astrophysics Data System (ADS)

Herbert, B. E.; McNeal, K. S.

2006-12-01

The dynamics of soil microbial ecosystems and labile fractions of soil organic matter in grasslands have important implications for the response of these critical ecosystems to perturbations. Organic, inorganic and genetic biomarkers in the solid (e.g. lipids, microbial DNA), liquid (e.g. porewater ions) or gaseous phases (e.g. carbon dioxide) have been used to characterize carbon cycling and soil microbial ecology. These proxies are generally limited in the amount of temporal information that they can provide (i.e., solid-phase proxies) or the amount of specific information they can provide about carbon sources or microbial community processes (e.g. inorganic gases). It is the aim of this research to validate the use of soil volatile organic carbon emissions (VOCs) as useful indicators of subsurface microbial community shifts and processes as a function of ecosystem perturbations. We present results of method validation using laboratory microcosm, where VOC metabolites as characterized by gas chromatography and mass spectrometry (GC-MS), were related to other proxies including carbon dioxide (CO2) via infra-red technology, and microbial community shifts as measured by Biolog© and fatty acid methyl ester (FAME) techniques. Experiments with soil collected from grasslands along the coastal margin region in southern Texas were preformed where environmental factors such as soil water content, soil type, and charcoal content are manipulated. Results indicate that over fifty identifiable VOC metabolites are produced from the soils, where many (~15) can be direct indicators of microbial ecology. Principle component analysis (PCA) evidences these trends through similar cluster patterns for the VOC results, the Biolog© results, and FAME. Regression analysis further shows that VOCs are significant (p < 0.05) indicators of microbial stress. Our results are encouraging that characterizing VOCs production in grassland soils are easy to measure, relatively inexpensive method, and useful proxies of subsurface microbial ecosystems and the dynamics of labile carbon in these systems.

PIMS:Remediation of Soil and Groundwater Contaminated With Metals

DTIC Science & Technology

2006-06-01

24 4.4.1.1 Bioremediation/ Phytoremediation ...........................................24 4.4.1.2 Physical...ii 5.3.2 Grouting and Off-Site Disposal .................................................................31 5.3.3 Phytoremediation ...Above Background in Sieved Soil ...................................... 12 Table 3. Leachate Monitoring Results

Laboratory-based characterization of plutonium in soil particles using micro-XRF and 3D confocal XRF

DOE PAGES

McIntosh, Kathryn Gallagher; Cordes, Nikolaus Lynn; Patterson, Brian M.; ...

2015-03-29

The investigation of plutonium (Pu) in a soil matrix is of interest in safeguards, nuclear forensics, and environmental remediation activities. The elemental composition of two plutonium contaminated soil particles was characterized nondestructively using a pair of micro X-ray fluorescence spectrometry (micro-XRF) techniques including high resolution X-ray (hiRX) and 3D confocal XRF. The three dimensional elemental imaging capability of confocal XRF permitted the identification two distinct Pu particles within the samples: one external to the Ferich soil matrix and another co-located with Cu within the soil matrix. The size and morphology of the particles was assessed with X-ray transmission microscopy andmore » micro X-ray computed tomography (micro-CT) providing complementary morphological information. Limits of detection for a 30 μm Pu particle are <10 ng for each of the XRF techniques. Ultimately, this study highlights the capability for lab-based, nondestructive, spatially resolved characterization of heterogeneous matrices on the micrometer scale with nanogram sensitivity.« less

Accumulation, sources and health risks of trace metals in elevated geochemical background soils used for greenhouse vegetable production in southwestern China.

PubMed

Zhang, Haidong; Huang, Biao; Dong, Linlin; Hu, Wenyou; Akhtar, Mohammad Saleem; Qu, Mingkai

2017-03-01

Greenhouse vegetable cultivation with substantive manure and fertilizer input on soils with an elevated geochemical background can accumulate trace metals in soils and plants leading to human health risks. Studies on trace metal accumulation over a land use shift duration in an elevated geochemical background scenario are lacking. Accumulation characteristics of seven trace metals in greenhouse soil and edible plants were evaluated along with an assessment of the health risk to the consumers. A total of 118 greenhouse surface soils (0-20cm) and 30 vegetables were collected from Kunming City, Yunnan Province, southwestern China, and analyzed for total Cd, Pb, Cu, Zn, As, Hg, and Cr content by ICP-MS and AFS. The trace metals were ordered Cu>Cd>Hg>Zn>Pb>As>Cr in greenhouse soils accumulation level, and the geo-accumulation index suggested the soil more severely polluted with Cd, Cu, Hg and Zn. The greenhouse and open-field soils had significant difference in Cd, Cr and Zn. The duration of shift from paddy to greenhouse land-use significantly influenced trace metal accumulation with a dramatic change during five to ten year greenhouse land-use, and continuous increase of Cd and Hg. A spatial pattern from north to south for Cd and Hg and a zonal pattern for Cu and Zn were found. An anthropogenic source primarily caused trace metal accumulation, where the principal component analysis/multiple linear regression indicated a contribution 61.2%. While the assessment showed no potential risk for children and adults, the hazard health risks index was greater than one for adolescents. The extended duration of land use as greenhouses caused the trace metal accumulation, rotation in land use should be promoted to reduce the health risks. Copyright © 2016. Published by Elsevier Inc.

Characterization of soils from an industrial complex contaminated with elemental mercury

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Carrie L., E-mail: millercl@ornl.gov; Watson, David B.; Lester, Brian P.

2013-08-15

Historical use of liquid elemental mercury (Hg(0){sub l}) at the Y-12 National Security Complex in Oak Ridge, TN, USA, resulted in large deposits of Hg(0){sub l} in the soils. The fate and distribution of the spilled Hg(0) are not well characterized. In this study we evaluated analytical tools for characterizing the speciation of Hg in the contaminated soils and then used the analytical techniques to examine the speciation of Hg in two soil cores collected at the site. These include x-ray fluorescence (XRF), soil Hg(0) headspace analysis, and total Hg determination by acid digestion coupled with cold vapor atomic absorptionmore » (HgT). XRF was not found to be suitable for evaluating Hg concentrations in heterogeneous soils containing low concentration of Hg or Hg(0) because Hg concentrations determined using this method were lower than those determined by HgT analysis and the XRF detection limit is 20 mg/kg. Hg(0){sub g} headspace analysis coupled with HgT measurements yielded good results for examining the presence of Hg(0){sub l} in soils and the speciation of Hg. The two soil cores are highly heterogeneous in both the depth and extent of Hg contamination, with Hg concentrations ranging from 0.05 to 8400 mg/kg. In the first core, Hg(0){sub l} was distributed throughout the 3.2 m depth, whereas the second core, from a location 12 m away, contained Hg(0){sub l} in a 0.3 m zone only. Sequential extractions showed organically associated Hg dominant at depths with low Hg concentration. Soil from the zone of groundwater saturation showed reducing conditions and the Hg is likely present as Hg-sulfide species. At this depth, lateral Hg transport in the groundwater may be a source of Hg detected in the soil at the deeper soil depths. Overall, characterization of soils containing Hg(0){sub l} is difficult because of the heterogeneous distribution of Hg within the soils. This is exacerbated in industrial facilities where fill materials make up much of the soils and historical and continued reworking of the subsurface has remobilized the Hg. -- Highlights: • Presence of Hg(0) and chemical transformations control the Hg speciation in soil. • Redox reactions can result in the mobilization and sequestration of Hg in soils. • Analysis of soils containing Hg(0) is complex due to sample heterogeneity.« less

Evolution of Pedostructure Parameters Under Tillage Practices

USDA-ARS?s Scientific Manuscript database

The pedostructure (PS) concept is a physically-based method of soil characterization that defines a soil based on its structure and the relationship between structure and soil water behavior. There are 15 unique pedostructure parameters that define the macropore and micropore soil water behavior fo...

Safely coupling livestock and crop production systems: how rapidly do antibiotic resistance genes dissipate in soil following a commercial application of swine or dairy manure?

PubMed

Marti, Romain; Tien, Yuan-Ching; Murray, Roger; Scott, Andrew; Sabourin, Lyne; Topp, Edward

2014-05-01

Animal manures recycled onto crop production land carry antibiotic-resistant bacteria. The present study evaluated the fate in soil of selected genes associated with antibiotic resistance or genetic mobility in field plots cropped to vegetables and managed according to normal farming practice. Referenced to unmanured soil, fertilization with swine or dairy manure increased the relative abundance of the gene targets sul1, erm(B), str(B), int1, and IncW repA. Following manure application in the spring of 2012, gene copy number decayed exponentially, reaching background levels by the fall of 2012. In contrast, gene copy number following manure application in the fall of 2012 or spring of 2013 increased significantly in the weeks following application and then declined. In both cases, the relative abundance of gene copy numbers had not returned to background levels by the fall of 2013. Overall, these results suggest that under conditions characteristic of agriculture in a humid continental climate, a 1-year period following a commercial application of raw manure is sufficient to ensure that an additional soil burden of antibiotic resistance genes approaches background. The relative abundance of several gene targets exceeded background during the growing season following a spring application or an application done the previous fall. Results from the present study reinforce the advisability of treating manure prior to use in crop production systems.

Isolation and characterization of Chilembwe and Sinda Rock Phosphate solubilizing soil microorganisms

USDA-ARS?s Scientific Manuscript database

This study was conducted to isolate and characterize soil microorganisms capable of solubilizing Chilembwe and Sinda rock phosphates readily available in Zambia. Single isolates were obtained by direct plating and enrichment cultures with succinate, cellulose and glucose as the carbon sources. Isola...

Preparation, Characterization, and UV Irradiation of Mars Soil Analogues Under Simulated Martian Conditions to Support Detection of Molecular Biomarkers

NASA Astrophysics Data System (ADS)

Fornaro, T.; Brucato, J. R.; ten Kate, I. L.; Siljeström, S.; Steele, A.; Cody, G. D.; Hazen, R. M.

2018-04-01

We present laboratory activities of preparation, characterization, and UV irradiation processing of Mars soil analogues, which are key to support both in situ exploration and sample return missions devoted to detection of molecular biomarkers on Mars.

Characterization studies and indicated remediation methods for plutonium contaminated soils at the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murarik, T.M.; Wenstrand, T.K.; Rogers, L.A.

An initial soil characterization study was conducted to help identify possible remediation methods to remove plutonium from the Nevada Test Site and Tonapah Test Range surface soils. Results from soil samples collected across various isopleths at five sites indicate that the size-fraction distribution patterns of plutonium remain similar to findings from the Nevada Applied Ecology Group (NAEG) (1970's). The plutonium remains in the upper 10--15 cm of soils, as indicated in previous studies. Distribution of fine particles downwind'' of ground zero at each site is suggested. Whether this pattern was established immediately after each explosion or this resulted from post-shotmore » wind movement of deposited material is unclear. Several possible soil treatment scenarios are presented. Removal of plutonium from certain size fractions of the soils would alleviate the sites of much of the plutonium burden. However, the nature of association of plutonium with soil components will determine which remediation methods will most likely succeed.« less

Characterization studies and indicated remediation methods for plutonium contaminated soils at the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murarik, T.M.; Wenstrand, T.K.; Rogers, L.A.

An initial soil characterization study was conducted to help identify possible remediation methods to remove plutonium from the Nevada Test Site and Tonapah Test Range surface soils. Results from soil samples collected across various isopleths at five sites indicate that the size-fraction distribution patterns of plutonium remain similar to findings from the Nevada Applied Ecology Group (NAEG) (1970`s). The plutonium remains in the upper 10--15 cm of soils, as indicated in previous studies. Distribution of fine particles ``downwind`` of ground zero at each site is suggested. Whether this pattern was established immediately after each explosion or this resulted from post-shotmore » wind movement of deposited material is unclear. Several possible soil treatment scenarios are presented. Removal of plutonium from certain size fractions of the soils would alleviate the sites of much of the plutonium burden. However, the nature of association of plutonium with soil components will determine which remediation methods will most likely succeed.« less

Soil nutrients, bacterial communities, and veterinary pharmaceuticals in beef cattle backgrounding confinement on karst environment

USDA-ARS?s Scientific Manuscript database

The United States hosts the world’s largest grain fed beef production. Commercial beef production in the US consists of three tiers that include: cow-calf enterprises, cattle backgrounding/stockering, and feedlot finishing. Beef cattle backgrounding/stockering represents an intermediate between the ...

Microscopic and spectroscopic characterization of humic substances from a compost amended copper contaminated soil: main features and their potential effects on Cu immobilization.

PubMed

Medina, Jorge; Monreal, Carlos; Chabot, Denise; Meier, Sebastián; González, María Eugenia; Morales, Esteban; Parillo, Rita; Borie, Fernando; Cornejo, Pablo

2017-06-01

We characterized humic substances (HS) extracted from a Cu-contaminated soil without compost addition (C) or amended with a wheat straw-based compost (WSC) (H1), co-composted with Fe 2 O 3 (H2), or co-composted with an allophane-rich soil (H3). Extracted HS were characterized under electron microscopy (SEM/TEM), energy-dispersive X-ray (X-EDS), and Fourier transform infrared (FTIR) spectroscopy. In addition, HS extracted from WSC (H4) were characterized at pH 4.0 and 8.0 with descriptive purposes. At pH 4.0, globular structures of H4 were observed, some of them aggregating within a large network. Contrariwise, at pH 8.0, long tubular and disaggregated structures prevailed. TEM microscopy suggests organo-mineral interactions at scales of 1 to 200 nm with iron oxide nanoparticles. HS extracted from soil-compost incubations showed interactions at nanoscale with minerals and crystal compounds into the organic matrix of HS. Bands associated to acidic functional groups of HS may suggest potential sorption interactions with transition metals. We conclude that metal ions and pH have an important role controlling the morphology and configuration of HS from WSC. Characterization of H4 extracted from WSC showed that physicochemical protection of HS could be present in composting systems treated with inorganic materials. Finally, the humified fractions obtained from compost-amended soils may have an important effect on metal-retention, supporting their potential use in metal-contaminated soils.

Urban Enhancement of PM10 Bioaerosol Tracers Relative to Background Locations in the Midwestern United States

PubMed Central

Rathnayake, Chathurika M.; Metwali, Nervana; Baker, Zach; Jayarathne, Thilina; Kostle, Pamela A.; Thorne, Peter S.; O’Shaughnessy, Patrick T.; Stone, Elizabeth A.

2016-01-01

Bioaerosols are well-known immune-active particles that exacerbate respiratory diseases. Human exposures to bioaerosols and their resultant health impacts depend on their ambient concentrations, seasonal and spatial variation, and co-pollutants, which are not yet widely characterized. In this study, chemical and biological tracers of bioaerosols were quantified in respirable particulate matter (PM10) collected at three urban and three background sites in the Midwestern United States across four seasons in 2012. Endotoxins from gram negative bacteria (and a few gram positive bacteria), water-soluble proteins, and tracers for fungal spores (fungal glucans, arabitol and mannitol) were ubiquitous and showed significant seasonal variation and dependence on temperature. Fungal spores were elevated in spring and peaked in summer, following the seasonal growing cycle, while endotoxins peaked in autumn during the row crop harvesting season. Paired comparisons of bioaerosols in urban and background sites revealed significant urban enhancements in PM10, fungal glucans, endotoxins and water-soluble proteins relative to background locations, such that urban populations have a greater outdoor exposure to bioaerosols. These bioaerosols contribute, in part, to the urban excesses in PM10. Higher bioaerosol mass fractions in urban areas relative to background sites indicate that urban areas serve as a source of bioaerosols. Similar urban enhancements in water-soluble calcium and its correlation with bioaerosol tracers point towards wind-blown soil as an important source of bioaerosols in urban areas. PMID:27672535

Urban Enhancement of PM10 Bioaerosol Tracers Relative to Background Locations in the Midwestern United States.

PubMed

Rathnayake, Chathurika M; Metwali, Nervana; Baker, Zach; Jayarathne, Thilina; Kostle, Pamela A; Thorne, Peter S; O'Shaughnessy, Patrick T; Stone, Elizabeth A

2016-05-16

Bioaerosols are well-known immune-active particles that exacerbate respiratory diseases. Human exposures to bioaerosols and their resultant health impacts depend on their ambient concentrations, seasonal and spatial variation, and co-pollutants, which are not yet widely characterized. In this study, chemical and biological tracers of bioaerosols were quantified in respirable particulate matter (PM 10 ) collected at three urban and three background sites in the Midwestern United States across four seasons in 2012. Endotoxins from gram negative bacteria (and a few gram positive bacteria), water-soluble proteins, and tracers for fungal spores (fungal glucans, arabitol and mannitol) were ubiquitous and showed significant seasonal variation and dependence on temperature. Fungal spores were elevated in spring and peaked in summer, following the seasonal growing cycle, while endotoxins peaked in autumn during the row crop harvesting season. Paired comparisons of bioaerosols in urban and background sites revealed significant urban enhancements in PM 10 , fungal glucans, endotoxins and water-soluble proteins relative to background locations, such that urban populations have a greater outdoor exposure to bioaerosols. These bioaerosols contribute, in part, to the urban excesses in PM 10 . Higher bioaerosol mass fractions in urban areas relative to background sites indicate that urban areas serve as a source of bioaerosols. Similar urban enhancements in water-soluble calcium and its correlation with bioaerosol tracers point towards wind-blown soil as an important source of bioaerosols in urban areas.

Molecular characterization of soil bacterial community in a perhumid, low mountain forest.

PubMed

Lin, Yu-Te; Whitman, William B; Coleman, David C; Chih-Yu, Chiu

2011-01-01

Forest disturbance often results in changes in soil properties and microbial communities. In the present study, we characterized a soil bacterial community subjected to disturbance using 16S rRNA gene clone libraries. The community was from a disturbed broad-leaved, low mountain forest ecosystem at Huoshaoliao (HSL) located in northern Taiwan. This locality receives more than 4,000 mm annual precipitation, one of the highest precipitations in Taiwan. Based on the Shannon diversity index, Chao1 estimator, richness and rarefaction curve analysis, the bacterial community in HSL forest soils was more diverse than those previously investigated in natural and disturbed forest soils with colder or less humid weather conditions. Analysis of molecular variance also revealed that the bacterial community in disturbed soils significantly differed from natural forest soils. Most of the abundant operational taxonomic units (OTUs) in the disturbed soil community at HSL were less abundant or absent in other soils. The disturbances influenced the composition of bacterial communities in natural and disturbed forests and increased the diversity of the disturbed forest soil community. Furthermore, the warmer and humid weather conditions could also increase community diversity in HSL soils.

Carbon Storage in US Wetlands.

EPA Science Inventory

Background/Question/Methods Wetland soils contain some of the highest stores of soil carbon in the biosphere. However, there is little understanding of the quantity and distribution of carbon stored in US wetlands or of the potential effects of human disturbance on these stocks. ...

A simplified regional-scale electromagnetic induction - Salinity calibration model using ANOCOVA modeling techniques

USDA-ARS?s Scientific Manuscript database

Directed soil sampling based on geospatial measurements of apparent soil electrical conductivity (ECa) is a potential means of characterizing the spatial variability of any soil property that influences ECa including soil salinity, water content, texture, bulk density, organic matter, and cation exc...

Concurrent temporal stability of the apparent electrical conductivity and soil water content

USDA-ARS?s Scientific Manuscript database

Knowledge of spatio-temporal soil water content (SWC) variability within agricultural fields is useful to improve crop management. Spatial patterns of soil water contents can be characterized using the temporal stability analysis, however high density sampling is required. Soil apparent electrical c...

EFFECT OF SOIL PROPERTIES ON THE TOXICITY AND BIOAVAILABILITY OF METALS

EPA Science Inventory

Heavy metal and organic chemical contamination of soils is a worldwide problem posing a risk to humans and more directly, soil organisms. Due to widespread metal contamination, it is necessary to characterize soils suspected of metal contamination and determine if the metal le...

NEGLECTED COMPONENTS OF BIODIVERSITY: SOIL ORIBATID MITES, COMMUNITY STRUCTURE AND SOIL RECOVERY

EPA Science Inventory

Oribatid mites are an abundant and diverse component of soils in regional pine forests, and are valuable in characterizing the biodiversity of these forested lands. We sampled oribatid mites using soil cores and leaf litterbags, in young aggrading forest stands. Comparing these...

Contribution of soil fauna to soil functioning in degraded environments: a multidisciplinary approach

NASA Astrophysics Data System (ADS)

Gargiulo, Laura; Mele, Giacomo; Moradi, Jabbar; Kukla, Jaroslav; Jandová, Kateřina; Frouz, Jan

2016-04-01

The restoration of the soil functions is essential for the recovery of highly degraded sites and, consequently, the study of the soil fauna role in the soil development in such environments has great potential from a practical point of view. The soils of the post-mining sites represent unique models for the study of the natural ecological succession because mining creates similar environments characterized by the same substrate, but by different ages according to the year of closure of mines. The aim of this work was to assess the contribution of different species of macrofauna on the evolution of soil structure and on the composition and activity of the microbial community in soil samples subjected to ecological restoration or characterized by spontaneous ecological succession. For this purpose, an experimental test was carried out in two sites characterized by different post-mining conditions: 1) natural succession, 2) reclamation with planting trees. These sites are located in the post-mining area of Sokolov (Czech Republic). For the experimental test repacked soil cores were prepared in laboratory with sieved soil sampled from the two sites. The soil cores were prepared maintaining the sequence of soil horizons present in the field. These samples were inoculated separately with two genera of earthworms (Lumbricus and Aporrectodea) and two of centipedes (Julida and Polydesmus). In particular, based on their body size, were inoculated for each cylinder 2 individuals of millipedes, 1 individual of Lumbricus and 4 individuals of Aporrectodea. For each treatment and for control samples 5 replicates were prepared and all samples were incubated in field for 1 month in the two original sampling sites. After the incubation the samples were removed from the field and transported in laboratory in order to perform the analysis of microbial respiration, of PLFA (phospholipid-derived fatty acids) and ergosterol contents and finally for the characterization of soil structure. All replicates were subjected to soil respiration measurement by means of chemical titration method. Then some replicates were destructively analyzed for PLFA and ergosterol and others were used for the 3D soil image analysis of the soil pore system. The soil cores were imaged using X-ray microtomography and three-dimensional image processing was performed in order to obtain 3D reconstructions and preliminary analysis of the identified biopores. The experimental approach used in this multidisciplinary study showed a promising potential to provide new useful information about the widely differentiated contribution of many types of macrofauna to the formation of the soil pore system and to the development of the soil microbial functions in different types of environments.

Successional trajectories of rhizosphere bacterial communities over consecutive seasons

DOE PAGES

Shi, Shengjing; Nuccio, Erin; Herman, Donald J.; ...

2015-08-04

It is well known that rhizosphere microbiomes differ from those of surrounding soil, and yet we know little about how these root-associated microbial communities change through the growing season and between seasons. We analyzed the response of soil bacteria to roots of the common annual grass Avena fatua over two growing seasons using high-throughput sequencing of 16S rRNA genes. Over the two periods of growth, the rhizosphere bacterial communities followed consistent successional patterns as plants grew, although the starting communities were distinct. Succession in the rhizosphere was characterized by a significant decrease in both taxonomic and phylogenetic diversity relative tomore » background soil communities, driven by reductions in both richness and evenness of the bacterial communities. Plant roots selectively stimulated the relative abundance of Alphaproteobacteria, Betaproteobacteria, and Bacteroidetes but reduced the abundance of Acidobacteria, Actinobacteria, and Firmicutes. Taxa that increased in relative abundance in the rhizosphere soil displayed phylogenetic clustering, suggesting some conservation and an evolutionary basis for the response of complex soil bacterial communities to the presence of plant roots. The reproducibility of rhizosphere succession and the apparent phylogenetic conservation of rhizosphere competence traits suggest adaptation of the indigenous bacterial community to this common grass over the many decades of its presence. We document the successional patterns of rhizosphere bacterial communities associated with a “wild” annual grass, Avena fatua, which is commonly a dominant plant in Mediterranean-type annual grasslands around the world; the plant was grown in its grassland soil. Most studies documenting rhizosphere microbiomes address “domesticated” plants growing in soils to which they are introduced. Rhizosphere bacterial communities exhibited a pattern of temporal succession that was consistent and repeatable over two growing seasons. There are few studies assessing the reproducibility over multiple seasons. Through the growing season, the rhizosphere community became progressively less diverse, likely reflecting root homogenization of soil microniches. Phylogenetic clustering of the rhizosphere dynamic taxa suggests evolutionary adaptation to Avena roots. The reproducibility of rhizosphere succession and the apparent phylogenetic conservation of rhizosphere competence traits suggest adaptation of the indigenous bacterial community to this common grass over the many decades of its presence.« less

Successional trajectories of rhizosphere bacterial communities over consecutive seasons

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, Shengjing; Nuccio, Erin; Herman, Donald J.

It is well known that rhizosphere microbiomes differ from those of surrounding soil, and yet we know little about how these root-associated microbial communities change through the growing season and between seasons. We analyzed the response of soil bacteria to roots of the common annual grass Avena fatua over two growing seasons using high-throughput sequencing of 16S rRNA genes. Over the two periods of growth, the rhizosphere bacterial communities followed consistent successional patterns as plants grew, although the starting communities were distinct. Succession in the rhizosphere was characterized by a significant decrease in both taxonomic and phylogenetic diversity relative tomore » background soil communities, driven by reductions in both richness and evenness of the bacterial communities. Plant roots selectively stimulated the relative abundance of Alphaproteobacteria, Betaproteobacteria, and Bacteroidetes but reduced the abundance of Acidobacteria, Actinobacteria, and Firmicutes. Taxa that increased in relative abundance in the rhizosphere soil displayed phylogenetic clustering, suggesting some conservation and an evolutionary basis for the response of complex soil bacterial communities to the presence of plant roots. The reproducibility of rhizosphere succession and the apparent phylogenetic conservation of rhizosphere competence traits suggest adaptation of the indigenous bacterial community to this common grass over the many decades of its presence. We document the successional patterns of rhizosphere bacterial communities associated with a “wild” annual grass, Avena fatua, which is commonly a dominant plant in Mediterranean-type annual grasslands around the world; the plant was grown in its grassland soil. Most studies documenting rhizosphere microbiomes address “domesticated” plants growing in soils to which they are introduced. Rhizosphere bacterial communities exhibited a pattern of temporal succession that was consistent and repeatable over two growing seasons. There are few studies assessing the reproducibility over multiple seasons. Through the growing season, the rhizosphere community became progressively less diverse, likely reflecting root homogenization of soil microniches. Phylogenetic clustering of the rhizosphere dynamic taxa suggests evolutionary adaptation to Avena roots. The reproducibility of rhizosphere succession and the apparent phylogenetic conservation of rhizosphere competence traits suggest adaptation of the indigenous bacterial community to this common grass over the many decades of its presence.« less

Mineralogy and arsenic mobility in arsenic-rich Brazilian soils and sediments

USGS Publications Warehouse

de Mello, J.W.V.; Roy, W.R.; Talbott, J.L.; Stucki, J.W.

2006-01-01

Background. Soils and sediments in certain mining regions of Brazil contain an unusually large amount of arsenic (As), which raises concerns that mining could promote increased As mobility, and thereby increase the risks of contaminating water supplies. Objectives. The purpose of t his study was to identify the most important factors governing As mobility in sediments and soils near three gold-mining sites in the State of Minas Gerais, Brazil. Methods. Surface and sub-surface soil samples were collected at those sites and characterized by chemical and mineralogical analyses. Oxalate (Feo) and citrate-bicarbonate-dithionite (Fed) iron contents were determined by atomic absorption spectroscopy (AAS). Arsenic mobilization was measured after incubating the samples in a 2.5 mM CaCl2 solution under anaerobic conditions for 1, 28, 56, 84, or 112 days. The solution concentrations of As, Fe, and Mn were then measured by inductively coupled plasma-mass spectrometry (ICP-MS) and AAS, respectively. Results and Discussion. Results indicated that As mobilization is largely independent of both the total As and the Feo/Fed ratio of the solid phase. Soluble As is roughly controlled by the Fe (hydr)oxide content of the soil, but a closer examination of the data revealed the importance of other highly weathered clay minerals and organic matter. Large amounts of organic matter and a low iron oxide content should favor As leaching from soils and sediments. Under reducing conditions, As is mobilized by the reductive dissolution of Fe and/or Mn oxides. However, released As may be readsorbed depending on the sorptive properties of the soil. Gibbsite is particularly effective in adsorbing or readsorbing As, as is the remaining unreduced fraction of the iron (hydr)oxides. Conclusion and Outlook. In general, low soluble As is rel ated to the presence of gibbsite, a large amount of iron oxides, and a lack of organic matter in the solid phase. This has environmental significance because gibbsite is thermodynamically more stable than Fe oxides under anaerobic conditions, such as those found in waterlogged soils and lake sediments. ?? 2006 ecomed publishers (Verlagsgruppe Hu??thig Jehle Rehm GmbH), D-86899 Landsberg and Tokyo.

Designing a generalized soil-adjusted vegetation index (GESAVI)

NASA Astrophysics Data System (ADS)

Gilabert, M. A.; Gonzalez Piqueras, Jose; Garcia-Haro, Joan; Melia, J.

1998-12-01

Operational monitoring of vegetative cover by remote sensing currently involves the utilization of vegetation indices (VIs), most of them being functions of the reflectance in red (R) and near-infrared (NIR) spectral bands. A generalized soil-adjusted vegetation index (GESAVI), theoretically based on a simple vegetation canopy model, is introduced. It is defined in terms of the soil line parameters (A and B) as: GESAVI equals (NIR-BR-A)/(R + Z), where Z is related to the red reflectance at the cross point between the soil line and vegetation isolines. Z can be considered as a soil adjustment coefficient which let this new index be considered as belonging to the SAVI family. In order to analyze the GESAVI sensitivity to soil brightness and soil color, both high resolution reflectance data from two laboratory experiments and data obtained by applying a radiosity model to simulate heterogeneous vegetation canopy scenes were used. VIs (including GESAVI, NDVI, PVI and SAVI family VIs) were computed and their correlation with LAI for the different soil backgrounds was analyzed. Results confirmed the lower sensitivity of GESAVI to soil background in most of the cases, thus becoming the most efficient index. This good index performance results from the fact that the isolines in the NIR-R plane are neither parallel to the soil line (as required by the PVI) nor convergent at the origin (as required by the NDVI) but they converge somewhere between the origin and infinity in the region of negative values of both NIR and R. This convergence point is not necessarily situated on the bisectrix, as required by other SAVI family indices.

Characterization of high elevation central Appalachian wetlands

Treesearch

K.E. Francl; W.M. Ford; S.B. and Castleberry

2004-01-01

We characterized 20 high elevation wetlands in the central Appalachian Mountains in West Virginia and Maryland, in terms of vegetation, soils, hydrology, and geology. Plant species were distributed along soil chemical (pH, conductivity) and physical (organic matter depth) gradients across sites. Topography and geology appear to explain differences among these wetlands...

Biologically Active Organic Matter in Soils of European Russia

NASA Astrophysics Data System (ADS)

Semenov, V. M.; Kogut, B. M.; Zinyakova, N. B.; Masyutenko, N. P.; Malyukova, L. S.; Lebedeva, T. N.; Tulina, A. S.

2018-04-01

Experimental and literature data on the contents and stocks of active organic matter in 200 soil samples from the forest-tundra, southern-taiga, deciduous-forest, forest-steppe, dry-steppe, semidesert, and subtropical zones have been generalized. Natural lands, agrocenoses, treatments of long-term field experiments (bare fallow, unfertilized and fertilized crop rotations, perennial plantations), and different layers of soil profile are presented. Sphagnum peat and humus-peat soil in the tundra and forest-tundra zones are characterized by a very high content of active organic matter (300-600 mg C/100 g). Among the zonal soils, the content of active organic matter increases from the medium (75-150 mg C/100 g) to the high (150-300 mg C/100 g) level when going from soddy-podzolic soil to gray forest and dark-gray forest soils and then to leached chernozem. In the series from typical chernozem to ordinary and southern chernozem and chestnut and brown semidesert soils, a decrease in the content of active organic matter to the low (35-75 mg C/100 g) and very low (<35 mg C/100 g) levels is observed. Acid brown forest soil in the subtropical zone is characterized by a medium supply with active organic matter. Most arable soils are mainly characterized by low or very low contents of active organic matter. In the upper layers of soils, active organic matter makes up 1.2-11.1% of total Corg. The profile distribution of active organic matter in the studied soils coincides with that of Corg: their contents appreciably decrease with depth, except for brown semidesert soil. The stocks of active organic matter vary from 0.4 to 5.4 t/ha in the layer of 0-20 cm and from 1.0 to 12.4/ha in the layer of 0-50 cm of different soil types.

Assessment of chemical element migration in soil-plant complex of Urov endemic localities of East Transbaikalia

NASA Astrophysics Data System (ADS)

Vadim V., Ermakov; Valentina, Danilova; Sabsbakhor, Khushvakhtova; Aklexander, Degtyarev; Sergey, Tyutikov; Victor, Berezkin; Elena, Karpova

2014-05-01

The comparative evaluation of the levels of biologically active chemical elements and their migration in the soil-plant complex of two Urov endemic locations in East Transbaikalia (Zolinsky and Uryumkansky) and background areas (Western Baikal region and the western area of the Trans-Baikal region) was conducted. The predominant soil-forming rocks in East Transbaikalia are weathering products of Proterozoic carbonated granitoids PR2. The surface rocks consist from granite, granodiorite, diorite quartz diorite, gabbro, norite, gabbro-norite and other. Soils - mountain and cryogenic meadow forests, mountain permafrost taiga podzolised, meadow alluvial, peaty meadow [2]. The paludification of narrow valleys and thermokarst phenomena are typical in Urov endemic localities. It reflects on the spotted of soil and differentiation of chemical composition of soils and plants. Most of the chemical elements in soils were determined by means of X-ray fluorescence, and trace elements in soils and plants - by atomic absorption spectrometry. The selenium content was measured by spectrofluorimetric method [3]. The research processed by methods of variation statistics. It was found that the soils of two locations of the Urov subregion of the biosphere were more enriched with iron, barium, calcium, uranium, thorium, phosphorus, and to a lesser extent strontium compared to background soils. The ratio of Ca: P was significantly higher in the soil of background areas, and Ca: Sr, on the contrary, in endemic soils. In assessing the migration of trace elements in soil-plant complex by means of the total content of trace elements and biological absorption coefficient found a marked accumulation by plants manganese, chromium, arsenic and weak plants accumulation of cobalt and nickel. Soil landscape is not much different in content of selenium, but its migration in plants was reduced in places of spread of Urov disease [1]. The concentrators of cadmium (leaves of different species of willow - Salicaceae) and selenium (needles of larch - Larix sibirica L.) were found among the plants. References 1. Ermakov V., Jovanovic L. Characteristics of selenium migration in soil-plant system of East Meshchera and Transbaikalia// J. Geochem. Explor., 2010. Vol. 107, 200-205. 2. Ermakov Vadim, Jovanovic Larisa, Berezkin Victor, Tyutikov Sergey, Danilogorskaya Anastasiya, Danilova Valentina, Krechetova Elena, Degtyarev Alexander, Khushvakhtova Sabsbakhor. Chemical assessment of soil and water of Urov biogeochemical provinces of Eastern Transbaikalia// Ecologica, 2012. Vol. 19, 69, 5-9. 3. Ermakov V.V., Tuytikov S.F. Khushvakhtova S.D., Danilova V.N. Boev V.A., Barabanschikova R.N., Chudinova E.A. Peculiarities of quantitative determination of selenium in biological materials// Bulletin of the Tyumen State University Press, 2010, 3, 206-214. Supported by the Russian Foundation for Basic Research, grant number 12-05-00141a.

Geophysical and Geotechnical Characterization of Beta-1,3/1,6-glucan Biopolymer treated Soil

NASA Astrophysics Data System (ADS)

Chang, I.; Cho, G.

2012-12-01

Bacteria or microbes in soil excrete hydrocarbon (e.g. polysaccharide) by-products which are called biopolymers. These biopolymers (or sometime biofilms) recently begun to make a mark on soil erosion control, aggregate stabilization, and drilling enhancement. However, the biological effect on soil behavior (e.g. bio-clogging or bio-cementation) has been poorly understood. In this study, the bio-cementation and bio-clogging effect induced by the existence of β-1,3/1,6-glucan biopolymers in soil were evaluated through a series of geophysical and geotechnical characterization tests in laboratory. According to the experimental test results, as the β-1,3/1,6-glucan content in soil increases, the compressive strength and shear wave velocity increase (i.e., bio-cementation) while the hydraulic conductivity decreases (i.e., bio-clogging) but the electrical conductivity increases due to the high electrical conductivity characteristic of β-1,3/1,6-glucan fibers. Coefficient of consolidation variation with the increases of β-1,3/1,6-glucan content in soil. SEM image of β-1,3/1,6-glucan treated soil. Fibers are form matices with soil particles.

Characterization and risk of exposure to elements from artisanal gold mining operations in the Bolivian Andes.

PubMed

Pavilonis, Brian; Grassman, Jean; Johnson, Glen; Diaz, Yilmael; Caravanos, Jack

2017-04-01

Artisanal and small-scale gold mining (ASGM) offers low-skilled workers an opportunity to elevate themselves out of poverty. However, this industry operates with little to no pollution controls and the cost to the environment and human health can be large. The objectives of this study were to measure levels of arsenic (As), manganese (Mn), cobalt (Co), lead (Pb), and mercury (Hg) in the environment and characterize health risks to miners and residents in an area with active ASGM operations. An exposure assessment was conducted at two different mining sites and a nearby village in the Bolivian Anders. The resulting measurements were then used to quantify cancerous and noncancerous health risks to children and adults working at and living near ASGM areas. Soil concentrations of As were well above background levels and showed great variations between the village and mining area. Mercury vapor levels at the two mining sites were approximately 30 times larger than the EPA reference concentration. The risk of developing non-cancerous health effects were primarily due to exposure to As and Hg. The probability of individuals developing cancer was considerably increased with adult miners having a probability of 1.3 out of 100. Cancer potential was driven by exposure to As, with de minimus cancer risk from all other elements. Based on the environmental characterization of elements in soils and Hg vapors, the risk of developing cancerous and non-cancerous health outcomes were above a level of concern based on EPA risk assessment guidance. Personal protective equipment was not worn by workers and Hg amalgam is commonly heated in workers' homes. Better education of the risks of ASGM is needed as well as simple controls to reduce exposure. Published by Elsevier Inc.

Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities.

PubMed

Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J; Mora, María de la Luz; Pozo, María J

2017-01-01

Wheat production around the world is severely compromised by the occurrence of "take-all" disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous "Mapuche" communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control.

Soil organic matter dynamics and CO2 fluxes in relation to landscape scale processes: linking process understanding to regional scale carbon mass-balances

NASA Astrophysics Data System (ADS)

Van Oost, Kristof; Nadeu, Elisabet; Wiaux, François; Wang, Zhengang; Stevens, François; Vanclooster, Marnik; Tran, Anh; Bogaert, Patrick; Doetterl, Sebastian; Lambot, Sébastien; Van wesemael, Bas

2014-05-01

In this paper, we synthesize the main outcomes of a collaborative project (2009-2014) initiated at the UCL (Belgium). The main objective of the project was to increase our understanding of soil organic matter dynamics in complex landscapes and use this to improve predictions of regional scale soil carbon balances. In a first phase, the project characterized the emergent spatial variability in soil organic matter storage and key soil properties at the regional scale. Based on the integration of remote sensing, geomorphological and soil analysis techniques, we quantified the temporal and spatial variability of soil carbon stock and pool distribution at the local and regional scales. This work showed a linkage between lateral fluxes of C in relation with sediment transport and the spatial variation in carbon storage at multiple spatial scales. In a second phase, the project focused on characterizing key controlling factors and process interactions at the catena scale. In-situ experiments of soil CO2 respiration showed that the soil carbon response at the catena scale was spatially heterogeneous and was mainly controlled by the catenary variation of soil physical attributes (soil moisture, temperature, C quality). The hillslope scale characterization relied on advanced hydrogeophysical techniques such as GPR (Ground Penetrating Radar), EMI (Electromagnetic induction), ERT (Electrical Resistivity Tomography), and geophysical inversion and data mining tools. Finally, we report on the integration of these insights into a coupled and spatially explicit model and its application. Simulations showed that C stocks and redistribution of mass and energy fluxes are closely coupled, they induce structured spatial and temporal patterns with non negligible attached uncertainties. We discuss the main outcomes of these activities in relation to sink-source behavior and relevance of erosion processes for larger-scale C budgets.

Radiocarbon in Ecosystem Respiration and Soil Pore-Space CO2 with Surface Gas Flux, Air Temperature, and Soil Temperature and Moisture, Barrow, Alaska, 2012-2014

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lydia Vaughn; Margaret Torn; Rachel Porras

Dataset includes Delta14C measurements made from CO2 that was collected and purified in 2012-2014 from surface soil chambers, soil pore space, and background atmosphere. In addition to 14CO2 data, dataset includes co-located measurements of CO2 and CH4 flux, soil and air temperature, and soil moisture. Measurements and field samples were taken from intensive study site 1 areas A, B, and C, and the site 0 and AB transects, from specified positions in high-centered, flat-centered, and low centered polygons.

Artificial and natural radionuclides in soils of the southern and middle taiga zones of Komi Republic

NASA Astrophysics Data System (ADS)

Beznosikov, V. A.; Lodygin, E. D.; Shuktomova, I. I.

2017-07-01

Specific activities of artificial (137Cs, 90Sr) and natural (40K, 232Th, 226Ra) radionuclides in background soils of southern and middle taiga of Komi Republic have been estimated with consideration for the landscape-geochemical features of the territory. It has been shown that their accumulation and migration in soils are determined by the following factors: position in relief, texture, and organic matter content. No anomalous zones with increased contents of radionuclides in soils have been revealed.

Saturated hydrocarbons in the background and contaminated soils of the cisurals

NASA Astrophysics Data System (ADS)

Gabov, D. N.; Beznosikov, V. A.; Kondratenok, B. M.; Gruzdev, I. V.

2010-10-01

A homologous series of n-alkanes (C20-C35) was identified in peaty-podzolic-gleyic soils. Structures with odd numbers of carbon atoms (C25-C35) were predominant in the soil organic matter. It was found that the major amount of both odd and even n-alkanes was accumulated in the peaty litter. In the mineral horizons, the mass fraction of the odd n-alkanes abruptly decreased to become comparable to that of the even n-alkanes in the soil-forming rock.

The distribution of a non-native (Rosa multiflora) and native (Kalmia latifolia) shrub in mature closed-canopy forests across soil fertility gradients

Treesearch

Cynthia D. Huebner; Jim Steinman; Todd F. Hutchinson; Todd E. Ristau; Alejandro A. Royo

2014-01-01

Background and aims. A soil fertility gradient, ranging from infertile to highly fertile soils, may define whether or not a plant will establish and spread at a site. We evaluated whether or not such a fertility gradient exists for Rosa multiflora Thunb., a nonnative invasive shrub, and Kalmia latifolia L., a...

Estimating COCOM Natural Background Dormancy

DTIC Science & Technology

2015-04-01

Goode and Espenshade 1953). Maps from Goode’s World Atlas included natural vegetation, agricultural regions, and soils . Clark University provided...and shallow, high mountain soils (Chambers 1967). The vertical stripes indi- cate a probability of more than two weeks of snow cover during the month...needle-leaf evergreen and deciduous trees during dormant or dry season, and desert alluvial deposits, sand, and thin mountain soils 6 Needle-leaf

Spatio-temporal patterns of soil water storage under dryland agriculture at the watershed scale

USDA-ARS?s Scientific Manuscript database

Soil water patterns vary significantly due to precipitation, soil properties, topographic features, and land use. We used empirical orthogonal function (EOF) analysis to characterize the spatial variability of soil water across a 37-ha field of the Washington State University Cook Agronomy Farm near...

A Study of Soil and Duricrust Models for Mars

NASA Technical Reports Server (NTRS)

Bishop, J. L.

2001-01-01

An analysis of soil and duricrust formation mechanisms on Mars is presented. Soil analog mixtures have been prepared, characterized and tested through wet/dry cycling experiments; results are compared with Mars Pathfinder soil data (spectral, chemical and magnetic). Additional information is contained in the original extended abstract.

Temporal Dynamics of Abundance and Composition of Nitrogen-Fixing Communities across Agricultural Soils

PubMed Central

Pereira e Silva, Michele C.; Schloter-Hai, Brigitte; Schloter, Michael; van Elsas, Jan Dirk; Salles, Joana Falcão

2013-01-01

Background Despite the fact that the fixation of nitrogen is one of the most significant nutrient processes in the terrestrial ecosystem, a thorough study of the spatial and temporal patterns in the abundance and distribution of N-fixing communities has been missing so far. Methodology/Principal Findings In order to understand the dynamics of diazotrophic communities and their resilience to external changes, we quantified the abundance and characterized the bacterial community structures based on the nifH gene, using real-time PCR, PCR-DGGE and 454-pyrosequencing, across four representative Dutch soils during one growing season. In general, higher nifH gene copy numbers were observed in soils with higher pH than in those with lower pH, but lower numbers were related to increased nitrate and ammonium levels. Results from nifH gene pyrosequencing confirmed the observed PCR-DGGE patterns, which indicated that the N fixers are highly dynamic across time, shifting around 60%. Forward selection on CCA analysis identified N availability as the main driver of these variations, as well as of the evenness of the communities, leading to very unequal communities. Moreover, deep sequencing of the nifH gene revealed that sandy soils (B and D) had the lowest percentage of shared OTUs across time, compared with clayey soils (G and K), indicating the presence of a community under constant change. Cosmopolitan nifH species (present throughout the season) were affiliated with Bradyrhizobium , Azospirillum and Methylocistis, whereas other species increased their abundances progressively over time, when appropriate conditions were met, as was notably the case for Paenibacilus and Burkholderia. Conclusions Our study provides the first in-depth pyrosequencing analysis of the N-fixing community at both spatial and temporal scales, providing insights into the cosmopolitan and specific portions of the nitrogen fixing bacterial communities in soil. PMID:24058578

Characterizing roots and water uptake in a ground cover rice production system

PubMed Central

Li, Sen; Zuo, Qiang; Wang, Xiaoyu; Ma, Wenwen; Jin, Xinxin; Shi, Jianchu; Ben-Gal, Alon

2017-01-01

Background and aims Water-saving ground cover rice production systems (GCRPS) are gaining popularity in many parts of the world. We aimed to describe the characteristics of root growth, morphology, distribution, and water uptake for a GCRPS. Methods A traditional paddy rice production system (TPRPS) was compared with GCRPS in greenhouse and field experiments. In the greenhouse, GCRPS where root zone average soil water content was kept near saturation (GCRPSsat), field capacity (GCRPSfwc) and 80% field capacity (GCRPS80%), were evaluated. In a two-year field experiment, GCRPSsat and GCRPS80% were applied. Results Similar results were found in greenhouse and field experiments. Before mid-tillering the upper soil temperature was higher for GCRPS, leading to enhanced root dry weight, length, surface area, specific root length, and smaller diameter of roots but lower water uptake rate per root length compared to TPRPS. In subsequent growth stages, the reduced soil water content under GCRPS caused that the preponderance of root growth under GCRPSsat disappeared in comparison to TPRPS. Under other GCRPS treatments (GCRPSfwc and GCRPS80%), significant limitation on root growth, bigger root diameter and higher water uptake rate per root length were found. Conclusions Discrepancies in soil water and temperature between TPRPS and GCRPS caused adjustments to root growth, morphology, distribution and function. Even though drought stress was inevitable after mid-tillering under GCRPS, especially GCRPS80%, similar or even enhanced root water uptake capacity in comparison to TPRPS might promote allocation of photosynthetic products to shoots and increase water productivity. PMID:28686687

Heavy metal pollution and forest health in the Ukrainian Carpathians.

PubMed

Shparyk, Y S; Parpan, V I

2004-07-01

The Ukrainian Carpathians are characterized by high air pollution caused by emissions from numerous industries. We have been monitoring the state of forests in this region since 1989. The highest levels of tree defoliation (>30%) are found close to industrial emission sources and in the upper mountain forests of the Ivano-Frankivsk and Chernivtsi regions. This is caused by a combination of strong anthropogenic influences (pollution, illegal uses, recreation) as well as poor site and climatic conditions. In the Ivano-Frankivsk region, Cd and Mo accumulate in forest soils; Cr, Mo and Zn soil concentrations are higher than their limit levels; and Pb concentrations exceed toxic levels close to industrial areas (10% of the region territory). Local background levels of heavy metals are greatly exceeded in snow close to industrial regions. Analysis of correlation matrices shows that the chemical elements Ba, Cd, Co, Cr, Cu, Mo, Ni, Pb, V and Zn occur at pollution levels in natural ecosystems in the Ukrainian Carpathians. Maximum concentrations of toxic elements occur in the oak forest zone; the most industrially developed area of the region. Toxic heavy metals in the Ukrainian Carpathians forests enter with precipitation and dustfall, then become fixed in soil and accumulate in leaves, needles of vascular plants and mosses. Concentrations of these metals decrease with altitude: highest in the oak forests, less in beech, and lowest in the spruce forest zones. However, some chemical elements have the highest concentrations in spruce forests; V in needles, As in snow, and Ba and Al in soils.

Nutrient Characterization of Rainwater, Soil and Groundwater from Two Different Watersheds, Lake Taihu, China

NASA Astrophysics Data System (ADS)

Thaw, M.; Gao, F.; Yu, Z.; Acharya, K.

2012-12-01

Over the past two decades, an increase of nutrients to Lake Taihu, China has resulted in hyper-eutrophication and the production of severe cyanobacterial blooms. While many past studies have focused on how surface water transports nutrients to the lake, this study seeks to characterize the concentration of nutrients in different media, including rainwater, soil and groundwater from two different watersheds. These two watersheds varied in overall land use, and agricultural sites within each watershed varied by crop type and growing method. Samples were collected from the Meilin watershed, a mix of forest and agricultural land and the Zhangjiagang watershed, which consisted of industrial, urban and agricultural lands. Samples included soils, groundwater and rain water. Soils from each site were characterized by aggregate size class and analyzed for total nitrogen and total phosphorus. Rainwater and groundwater samples were analyzed for total nitrogen and total phosphorus.

U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. French; E. Anthony; P. Goodell

2006-03-16

The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s amore » maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only to a few thousand years. The contribution of this study is that the short residence time of the ore at the Prior High Grade Stockpile requires a time span for mobilization of 20-30 years.« less

Spatial characterization of soil properties and influence in soil formation in oak-grassland of Sierra Morena, S Spain

NASA Astrophysics Data System (ADS)

Román-Sánchez, Andrea; Cáceres, Francisco; Pédèches, Remi; Giráldez Cervera, Juan Vicente; Vanwalleghem, Tom

2016-04-01

The Mediterranean oak-grassland ecosystem is very important for the rural economy and for the biodiversity of south-western European countries like Spain and Portugal. Nevertheless these ecosystems are not well characterized especially their soils. In this report soil carbon has been evaluated and related to other properties. The principal factors controlling the structure, productivity and evolution of forest ecosystems are bedrock, climate, relief, vegetation and time. Soil carbon has an important influence in the soil and ecosystem structures. The purpose of this study is to determine the relationship between relief, soil properties, spatial distribution of soil carbon and their influence in soil formation and geomorphology. This work is part of another study which aims to elucidate the processes involved in the soil formation and to examine their behaviour on long-term with a modelling. In our study area, located in oak-grassland of Sierra Morena, in Cordoba, S Spain, have been studied 67 points at 6 depths in 262 hectares in order to determine carbon content varying between 0-6%, soil properties such as soil depth between 0-4 m, horizon depth and the rocks amount in surface. The relationship between the soil carbon, soil properties and the relief characteristic like slope, aspect, curvature can shed light the processes that affect the mechanisms of bedrock weathering and their interrelationship with geomorphological processes.

Geochemical characterization of elements in Vitis vinifera cv. Negroamaro grape berries grown under different soil managements.

PubMed

Pepi, Salvatore; Coletta, Antonio; Crupi, Pasquale; Leis, Marilena; Russo, Sabrina; Sansone, Luigi; Tassinari, Renzo; Chicca, Milvia; Vaccaro, Carmela

2016-04-01

The present geochemical study concerns the impact of viticultural practices in the chemical composition of the grape cultivar "Negroamaro" in Apulia, a southern Italian region renowned for its quality wine. Three types of soil management (SM), two cover cropping with different mixtures, and a soil tillage were considered. For each SM, the vines were irrigated according to two irrigation levels. Chemical composition of soil and of berries of Vitis vinifera cultivar "Negroamaro" were analyzed by X-ray fluorescence, inductively coupled plasma-mass spectrometry and multivariate statistics (linear discrimination analysis). In detail, we investigated major and trace elements behavior in the soil according to irrigation levels, the related index of bioaccumulation (BA) and the relationship between trace element concentration and soil management in "Negroamaro" grapes. The results indicate that soil management affects the mobility of major and trace elements. A specific assimilation of these elements in grapes from vines grown under different soil management was confirmed by BA. Multivariate statistics allowed to associate the vines to the type of soil management. This geochemical characterization of elements could be useful to develop fingerprints of vines of the cultivar "Negroamaro" according to soil management and geographical origin.

The Modeling of the Effects of Soiling, Its Mechanisms, and the Corresponding Abrasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simpson, Lin; Muller, Matthew; Deceglie, Michael

2016-02-24

Decreasing LCOE with predictive soiling loss models (using site data to predict annualized energy loss), quantification of different soiling mechanisms (using AFM-based characterization), and developing standards for PV module coatings.

Soil Organic Matter Stability and Soil Carbon Storage with Changes in Land Use Intensity in Uganda

NASA Astrophysics Data System (ADS)

Tiemann, L. K.; Grandy, S.; Hartter, J.

2014-12-01

As the foundation of soil fertility, soil organic matter (SOM) formation and break-down is a critical factor of agroecosystem sustainability. In tropical systems where soils are quickly weathered, the link between SOM and soil fertility is particularly strong; however, the mechanisms controlling the stabilization and destabilization of SOM are not well characterized in tropical soils. In western Uganda, we collected soil samples under different levels of land use intensity including maize fields, banana plantations and inside an un-cultivated native tropical forest, Kibale National Park (KNP). To better understand the link between land use intensity and SOM stability we measured total soil C and N, and respiration rates during a 369 d soil incubation. In addition, we separated soils into particle size fractions, and mineral adsorbed SOM in the silt (2-50 μm ) and clay (< 2 μm) fractions was dissociated, purified and chemically characterized via pyrolysis-GC/MS. Cultivated soil C and N have declined by 22 and 48%, respectively, in comparison to uncultivated KNP soils. Incubation data indicate that over the last decade, relatively accessible and labile soil organic carbon (SOC) pools have been depleted by 55-59% in cultivated soils. As a result of this depletion, the chemical composition of SOM has been altered such that clay and silt associated SOM differed significantly between agricultural fields and KNP. In particular, nitrogen containing compounds were in lower abundance in agricultural compared to KNP soils. This suggests that N depletion due to agriculture has advanced to pools of mineral associated organic N that are typically protected from break-down. In areas where land use intensity is relatively greater, increases in polysaccharides and lipids in maize fields compared to KNP indicate increases in microbial residues and decomposition by-products as microbes mine SOM for organic N. Chemical characterization of post-incubation SOM will help us better understand how microbes preferentially break-down SOM. Agricultural intensification over the past decade in western Uganda has depleted SOC, on average, by 1427 g m-2. In addition, depletion of organic nitrogen reserves in stable SOM pools corresponds with reported declines in crop yields and productivity in this region.

Characterization of site conditions for selected seismic stations in eastern part of Romania

NASA Astrophysics Data System (ADS)

Grecu, B.; Zaharia, B.; Diaconescu, M.; Bala, A.; Nastase, E.; Constantinescu, E.; Tataru, D.

2018-02-01

Strong motion data are essential for seismic hazard assessment. To correctly understand and use this kind of data is necessary to have a good knowledge of local site conditions. Romania has one of the largest strong motion networks in Europe with 134 real-time stations. In this work, we aim to do a comprehensive site characterization for eight of these stations located in the eastern part of Romania. We make use of a various seismological dataset and we perform ambient noise and earthquake-based investigations to estimate the background noise level, the resonance frequencies and amplification of each site. We also derive the Vs30 parameter from the surface shear-wave velocity profiles obtained through the inversion of the Rayleigh waves recorded in active seismic measurements. Our analyses indicate similar results for seven stations: high noise levels for frequencies larger than 1 Hz, well defined fundamental resonance at low frequencies (0.15-0.29 Hz), moderate amplification levels (up to 4 units) for frequencies between 0.15 and 5-7 Hz and same soil class (type C) according to the estimated Vs30 and Eurocode 8. In contrast, the eighth station for which the soil class is evaluated of type B exhibits a very good noise level for a wide range of frequencies (0.01-20 Hz), a broader fundamental resonance at high frequencies ( 8 Hz) and a flat amplification curve between 0.1 and 3-4 Hz.

Edaphic factors controlling summer (rainy season) greenhouse gas emissions (CO2 and CH4) from semiarid mangrove soils (NE-Brazil).

PubMed

Nóbrega, Gabriel N; Ferreira, Tiago O; Siqueira Neto, M; Queiroz, Hermano M; Artur, Adriana G; Mendonça, Eduardo De S; Silva, Ebenezer De O; Otero, Xosé L

2016-01-15

The soil attributes controlling the CO2, and CH4 emissions were assessed in semiarid mangrove soils (NE-Brazil) under different anthropogenic activities. Soil samples were collected from different mangroves under different anthropogenic impacts, e.g., shrimp farming (Jaguaribe River); urban wastes (Cocó River) and a control site (Timonha River). The sites were characterized according to the sand content; physicochemical parameters (Eh and pH); total organic C; soil C stock (SCS) and equivalent SCS (SCSEQV); total P and N; dissolved organic C (DOC); and the degree of pyritization (DOP). The CO2 and CH4 fluxes from the soils were assessed using static closed chambers. Higher DOC and SCS and the lowest DOP promote greater CO2 emission. The CH4 flux was only observed at Jaguaribe which presented higher DOP, compared to that found in mangroves from humid tropical climates. Semiarid mangrove soils cannot be characterized as important greenhouse gas sources, compared to humid tropical mangroves.

Characterization of two diesel fuel degrading microbial consortia enriched from a non acclimated, complex source of microorganisms

PubMed Central

2010-01-01

Background The bioremediation of soils impacted by diesel fuels is very often limited by the lack of indigenous microflora with the required broad substrate specificity. In such cases, the soil inoculation with cultures with the desired catabolic capabilities (bioaugmentation) is an essential option. The use of consortia of microorganisms obtained from rich sources of microbes (e.g., sludges, composts, manure) via enrichment (i.e., serial growth transfers) on the polluting hydrocarbons would provide bioremediation enhancements more robust and reproducible than those achieved with specialized pure cultures or tailored combinations (co-cultures) of them, together with none or minor risks of soil loading with unrelated or pathogenic allocthonous microorganisms. Results In this work, two microbial consortia, i.e., ENZ-G1 and ENZ-G2, were enriched from ENZYVEBA (a complex commercial source of microorganisms) on Diesel (G1) and HiQ Diesel (G2), respectively, and characterized in terms of microbial composition and hydrocarbon biodegradation capability and specificity. ENZ-G1 and ENZ-G2 exhibited a comparable and remarkable biodegradation capability and specificity towards n-C10 to n-C24 linear paraffins by removing about 90% of 1 g l-1 of diesel fuel applied after 10 days of aerobic shaken flask batch culture incubation at 30°C. Cultivation dependent and independent approaches evidenced that both consortia consist of bacteria belonging to the genera Chryseobacterium, Acinetobacter, Psudomonas, Stenotrophomonas, Alcaligenes and Gordonia along with the fungus Trametes gibbosa. However, only the fungus was found to grow and remarkably biodegrade G1 and G2 hydrocarbons under the same conditions. The biodegradation activity and specificity and the microbial composition of ENZ-G1 and ENZ-G2 did not significantly change after cryopreservation and storage at -20°C for several months. Conclusions ENZ-G1 and ENZ-G2 are very similar highly enriched consortia of bacteria and a fungus capable of extensively degrading a broad range of the hydrocarbons mainly composing diesel fuels. Given their remarkable biodegradation potential, stability and resistance to cryopreservation, both consortia appear very interesting candidates for bioaugmentation operations on Diesel fuel impacted soils and sites. PMID:20158909

New insights on the Frasnian/Famennian mass extinction: a role for soil erosion?

NASA Astrophysics Data System (ADS)

Algeo, T.; Gordon, G.; Anbar, A.; Sauer, P.; Schwark, L.; Bates, S.; Lyons, T.; Turgeon, S.; Creaser, R.; Nabbefeld, B.; Grice, K.

2008-12-01

The Frasnian/Famennian (F/F) mass extinction, which killed off a previously thriving tabulate coral- stromatoporoid reef community, was the most severe biotic crisis of the middle Paleozoic. The present study examines the geochemistry of a 28-m stratigraphic interval straddling the F/F boundary in the West Valley drillcore from the northern Appalachian Basin (western New York State), comprising bioturbated shales of the Hanover Formation and mostly laminated shales of the overlying Dunkirk Formation. Paleoredox proxies (DOP, FeT/Al, δ98Mo) indicate an increase in the frequency and intensity of anoxia at the F/F boundary. Proxies for hydrographic conditions (Mo/TOC, Re/TOC, U/TOC) suggest that the depositional basin experienced an interval of deepwater restriction around the boundary, possibly as a consequence of eustatic fall. The boundary is characterized by a large decrease in Zr/Al, indicating lower silt:clay ratios, and by a large decrease in excess Ba (i.e., total Ba-detrital Ba), implying reduced levels of primary productivity. Organic C- and N-isotopic data provide evidence of a major change in organic matter fluxes commencing ~7 meters below the boundary and persisting ~10 m above it. This change is characterized by ca. +5‰ and +15‰ excursions in kerogen δ13C and total organic δ13C, respectively, and by short- term excursions in organic δ15N to as low as -1‰ CDT (from background values of +1 to +2‰) that may provide evidence of cyanobacterial N fixation. Biomarker analysis, still in progress, may provide additional clues concerning changes in organic matter sources. The existing data are consistent with a model of enhanced terrigenous siliciclastic flux to the northern Appalachian Basin at the F/F boundary linked to climatic cooling, eustatic regression, and soil erosion. The rapid development of soils as a consequence of the spread of vascular land plants during the Middle and Late Devonian (Algeo et al., 1995, GSA Today, v. 5(5)) may have created the potential for precipitating marine ecological crises through soil erosion events.

Amorphous Analogs of Martian Global Soil: Pair Distribution Function Analyses and Implications for Scattering Models of Chemin X-ray Diffraction Data

NASA Technical Reports Server (NTRS)

Achilles, C. N.; Bish, D. L.; Rampe, E. B.; Morris, R. V.

2015-01-01

Soils on Mars have been analyzed by the Mars Exploration Rovers (MER) and most recently by the Mars Science Laboratory (MSL) rover. Chemical analyses from a majority of soil samples suggest that there is a relatively uniform global soil composition across much of the planet. A soil site, Rocknest, was sampled by the MSL science payload including the CheMin X-ray diffractometer and the Alpha Particle X-ray Spectrometer (APXS). Che- Min X-ray diffraction (XRD) data revealed crystalline phases and a broad, elevated background, indicating the presence of amorphous or poorly ordered materials (Fig 1). Based on the chemical composition of the bulk soil measured by APXS and the composition of crystalline phases derived from unit-cell parameters determined with CheMin data, the percentages of crystalline and amorphous phases were calculated at 51% and 49%, respectively. Attempts to model the amorphous contribution to CheMin XRD patterns were made using amorphous standards and full-pattern fitting methods and show that the broad, elevated background region can be fitted by basaltic glass, allophane, and palagonite. However, the modeling shows only that these phases have scattering patterns similar to that for the soil, not that they represent unique solutions. Here, we use pair distribution function (PDF) analysis to determine the short-range order of amorphous analogs in martian soils and better constrain the amorphous material detected by CheMin.

Comparative statistical analysis of chrome and vegetable tanning effluents and their effects on related soil.

PubMed

Tariq, Saadia R; Shah, Munir H; Shaheen, Nazia

2009-09-30

Two tanning units of Pakistan, namely, Kasur and Mian Channun were investigated with respect to the tanning processes (chrome and vegetable, respectively) and the effects of the tanning agents on the quality of soil in vicinity of tanneries were evaluated. The effluent and soil samples from 16 tanneries each of Kasur and Mian Channun were collected. The levels of selected metals (Na, K, Ca, Mg, Fe, Cr, Mn, Co, Cd, Ni, Pb and Zn) were determined by using flame atomic absorption spectrophotometer under optimum analytical conditions. The data thus obtained were subjected to univariate and multivariate statistical analyses. Most of the metals exhibited considerably higher concentrations in the effluents and soils of Kasur compared with those of Mian Channun. It was observed that the soil of Kasur was highly contaminated by Na, K, Ca and Mg emanating from various processes of leather manufacture. Furthermore, the levels of Cr were also present at much enhanced levels than its background concentration due to the adoption of chrome tanning. The levels of Cr determined in soil samples collected from the vicinity of Mian Channun tanneries were almost comparable to the background levels. The soil of this city was found to have contaminated only by the metals originating from pre-tanning processes. The apportionment of selected metals in the effluent and soil samples was determined by a multivariate cluster analysis, which revealed significant differences in chrome and vegetable tanning processes.

The influences of inorganic elements in soil on the development of famous - region Atractylodes lancea (Thunb.) DC

PubMed Central

Zhang, Weiwanqi; Ouyang, Zhen; Zhao, Ming; Wei, Yuan; Peng, Huasheng; Wang, Qiang; Guo, Ling

2015-01-01

Background: Atractylodes lancea (Thunb.) DC., is an important medicinal plant in China. Recently, researches of A. Lancea were focused on chemical composition and genetics, only a few were concerned with soil factors. Objective: The aim was to discuss the relationship between geo-herbalism of A. Lancea (Thunb.) DC. and inorganic elements in soil. Materials and Methods: The contents of 15 kinds of inorganic elements in the rhizoma of A. Lancea (Thunb.) DC. and soils from various regions were determined with inductively coupled plasma-optical emission spectrometer and the data were analyzed with Statistical Package for the Social Sciences 20.0 software. Results: The contents of inorganic elements in rhizoma of A. Lancea and in soil with different geological background were different. The soils in the famous region contained high aluminum, iron, sodium and low sulfur content. The rhizoma of A. Lancea contained high aluminum, lithium, manganese and low iron, sulfur content. The famous-region crude drugs had a strong tendency to accumulate selenium, manganese. Ten characteristic elements of A. Lancea were K, Ca, S, Al, Li, Ti, Mn, Pb, Ni, SE. Conclusion: The contents of inorganic elements in rhizoma of A. Lancea showed a significant positive interrelationship with those in soil. It was identified that inorganic elements play an important role in forming authenticity A. Lancea (Thunb.) DC. PMID:25829773

Characterization of nicosulfuron availability in aged soils.

PubMed

Regitano, Jussara B; Koskinen, William C

2008-07-23

Sorption-desorption interactions of pesticides with soil determine their availability for transport, plant uptake, and microbial degradation. These interactions are affected by the physical-chemical properties of the pesticide and soil, and for some pesticides, their residence time in the soil. This research evaluated changes in sorption/availability of nicosulfuron (2-[[[[(4,6-dimethoxy-2-pyrimidinyl]amino]carbonyl]amino]sulfonyl]-N,N-dimethyl-3-pyridinecarboxamide) herbicide with aging in different soils, using a radiolabeled ((14)C) tracer. Aging significantly increased sorption. For instance, after the 41-day incubation, calculated K d,app increased by a factor of 2 to 3 in Mollisols from the Midwestern United States and by a factor of 5 to 9 in Oxisols from Brazil and Hawaii, as compared to freshly treated soils. In view of this outcome, potential transport of nicosulfuron would be overpredicted if freshly treated soil K d values were used to predict transport. The fact that the nicosulfuron solution concentration decreased faster than the soil concentration with time suggested that the increase in sorption was because the rate of degradation in solution and on labile sites was faster than the rate of desorption of the neutral species from the soil particles. It may have also been due to nicosulfuron anion diffusion to less accessible sites with time, leaving the more strongly bound neutral molecules for the sorption characterization. Regardless of the mechanism, these results are further evidence that increases in sorption during pesticide aging should be taken into account during the characterization of the sorption process for mathematical models of pesticide degradation and transport.

Soils in our big back yard: characterizing the state, vulnerabilities, and opportunities for detecting changes in soil carbon storage

NASA Astrophysics Data System (ADS)

Harden, Jennifer W.; Loiesel, Julie; Ryals, Rebecca; Lawrence, Corey; Blankinship, Joseph; Phillips, Claire; Bond-Lamberty, Ben; Todd-Brown, Katherine; Vargas, Rodrigo; Hugelius, Gustaf; Nave, Luke; Malhotra, Avni; Silver, Whendee; Sanderman, Jon

2017-04-01

A number of diverse approaches and sciences can contribute to a robust understanding of the I. state, II. vulnerabilities, and III. opportunities for soil carbon in context of its potential contributions to the atmospheric C budget. Soil state refers to the current C stock of a given site, region, or ecosystem/landuse type. Soil vulnerabilities refers to the forms and bioreactivity of C stocks, which determine how soil C might respond to climate, disturbance, and landuse perturbations. Opportunities refer to the potential for soils in their current state to increase capacity for and rate of C storage under future conditions, thereby impacting atmospheric C budgets. In order to capture the state, vulnerability, and opportunities for soil C, a robust C accounting scheme must include at least three science needs: (1) a user-friendly and dynamic database with transparent, shared coding in which data layers of solid, liquid, and gaseous phases share relational metadata and allow for changes over time (2) a framework to characterize the capacity and reactivity of different soil types based on climate, historic, and landscape factors (3) a framework to characterize landuse practices and their impact on physical state, capacity/reactivity, and potential for C change. In order to transfer our science information to practicable implementations for land policies, societal and social needs must also include: (1) metrics for landowners and policy experts to recognize conditions of vulnerability or opportunity (2)communication schemes for accessing salient outcomes of the science. Importantly, there stands an opportunity for contributions of data, model code, and conceptual frameworks in which scientists, educators, and decision-makers can become citizens of a shared, scrutinized database that contributes to a dynamic, improved understanding of our soil system.

Waste-water characterization survey, Whiteman Air Force Base, Missouri. Final report, 28 Oct-7 Nov 91

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, M.K.; Davis, R.P.

1992-08-01

A wastewater characterization survey was conducted by members of the Armstrong Laboratory Occupational and Environmental Health directorate Water Quality Function from 28 Oct 91 - 7 Nov 91 at Whiteman AFB, MO. The purpose of the survey was to identify and characterize the wastewater, determine the appropriateness of present disposal methods, determine the need for routine sampling or monitoring and recommend parameters for wastewater analysis. Results of the sampling showed metals and volatile organic discharge in varying concentrations throughout the base. Recommendations are: (1) evaluation of industrial operations and chemical disposal procedures at designated sites; (2) routine monitoring of themore » discharge from the Hospital and Audiovisual for silver; (3) excavation and sediment disposal at the Transportation Washrack and WWTP Effluent discharge point; (4) collection and analyses of sludge at oil water separators, to include the oil and water side; (5) evaluation of the sanitary sewer system for corrosion and sediment buildup by a mobile Reveal and Seal Unit; (6) background soil sample collection and analyses; and (7) pretreatment of Aqueous Film Forming Foam discharge and notification of the Base Bioenvironmental Engineer, Environmental Coordinator, and WWTP personnel when discharge occurs.« less

Terra Pretas: Charcoal Amendments Influence on Relict Soils and Modern Agriculture

ERIC Educational Resources Information Center

Ricigliano, Kristin

2011-01-01

Most soils found in the Amazon region are characterized by highly weathered profiles that are incapable of longterm agricultural production. However, small patches of highly fertile relict soil referred to as Terra Pretas, are also found in the Amazon region, and have maintained their integrity for thousands of years. These soils were…

COSMOS soil water sensor compared with EM sensor network & weighing lysimeter

USDA-ARS?s Scientific Manuscript database

Soil water sensing methods are widely used to characterize the root zone and below, but only a few are capable of delivering water content data with accuracy for the entire soil profile such that evapotranspiration (ET) can be determined by soil water balance and irrigations can be scheduled with mi...

Hyper-temporal remote sensing for digital soil mapping: Characterizing soil-vegetation response to climatic variability

USDA-ARS?s Scientific Manuscript database

Indices derived from remotely-sensed imagery are commonly used to predict soil properties with digital soil mapping (DSM) techniques. The use of images from single dates or a small number of dates is most common for DSM; however, selection of the appropriate images is complicated by temporal variabi...

Application of triple collocation in ground-based validation of soil moisture active/passive (SMAP) level 2 data products

USDA-ARS?s Scientific Manuscript database

The validation of the soil moisture retrievals from the recently-launched NASA Soil Moisture Active/Passive (SMAP) satellite is important prior to their full public release. Uncertainty in attempts to characterize footprint-scale surface-layer soil moisture using point-scale ground observations has ...

Soil structure characterized using computed tomographic images

Treesearch

Zhanqi Cheng; Stephen H. Anderson; Clark J. Gantzer; J. W. Van Sambeek

2003-01-01

Fractal analysis of soil structure is a relatively new method for quantifying the effects of management systems on soil properties and quality. The objective of this work was to explore several methods of studying images to describe and quantify structure of soils under forest management. This research uses computed tomography and a topological method called Multiple...

Soil erosion and deposition before and after fire in oak savannas

Treesearch

Peter F. Ffolliott; Gerald J. Gottfried; Hui Chen; Aaron T. Kauffman; Cody L. Stropki; Daniel G. Neary

2013-01-01

Effects of low severity prescribed burning treatments and a wildfire on soil erosion and deposition in the oak savannas in the Southwestern Borderlands are reported. Measurements in the spring and fall, respectively, characterize soil movements following winter rains and high-intensity summer rainstorms. Annual values are also presented. Relationships between soil...

Persistence and memory timescales in root-zone soil moisture dynamics

Treesearch

Khaled Ghannam; Taro Nakai; Athanasios Paschalis; Andrew C. Oishi; Ayumi Kotani; Yasunori Igarashi; Tomo' omi Kumagai; Gabriel G. Katul

2016-01-01

The memory timescale that characterizes root-zone soil moisture remains the dominant measure in seasonal forecasts of land-climate interactions. This memory is a quasi-deterministic timescale associated with the losses (e.g., evapotranspiration) from the soil column and is often interpreted as persistence in soil moisture states. Persistence, however,...

CONVERGING PATTERNS OF UPTAKE AND HYDRAULIC REDISTRIBUTION OF SOIL WATER IN CONTRASTING WOODY VEGETATION TYPES

EPA Science Inventory

We used concurrent measurements of soil water content and soil water potential (Ysoil) to assess the effects of Ysoil on uptake and hydraulic redistribution (HR) of soil water by roots during seasonal drought cycles in six sites characterized by different types and amounts of woo...

Chemical structure of soil organic matter in slickspots as investigated by advanced solid-state NMR

USDA-ARS?s Scientific Manuscript database

Slickspot soils are saline, and knowledge of their humic chemistry would contribute to our limited understanding how salinity affects soil C and N stocks. We characterized humic acids (HAs) from slickspot soils with solid-state 13C nuclear magnetic resonance (NMR). Expanding on previous use of cross...

Long-term fate of depleted uranium at Aberdeen and Yuma Proving Grounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebinger, M.H.; Essington, E.H.; Gladney, E.S.

1990-06-01

The environmental fate of fragments of depleted uranium (DU) penetrators in soils and waters at Aberdeen Proving Ground (APG) and Yuma Proving Ground (YPG) is a concern to the Testing and Evaluation Command (TECOM) of the US Army. This report presents the information from preliminary soil and water samples that were collected from the humid woodlands of APG and the arid Sonoran Desert of YPG. Soil samples collected beneath a penetrator fragment of the firing range at APG showed approximately 12% DU by weight in the surface horizon and DU significantly above background to a depth of about 20 cm.more » Samples of surface water at APG showed U only at background levels, and bottom sediments showed background U levels but with isotopic ratios of DU instead of natural U. Soil samples beneath a penetrator fragment at YPG showed about 0.5% by weight U in the surface horizon, but only background concentrations and isotopic ratios of U between 8 and 20 cm depth. Results from this preliminary study indicate that DU at APG was redistributed primarily be dissolution and transport with water and possibly by migration of DU colloids or DU attached to small particles. Redistribution at YPG, however, was mainly due to erosion of DU fragments from the impact area and redeposition in washes that drain the area. Proposed work for FY90-FY92 includes additional field sampling, laboratory column studies, and the development of a computer model of DU redistribution at both sites. 39 refs., 11 figs., 5 tabs.« less

Iodine-129 measurements in soil samples from Dolon village near the Semipalatinsk nuclear test site.

PubMed

Endo, Satoru; Tomita, Junpei; Tanaka, Kenichi; Yamamoto, Masayoshi; Fukutani, Satoshi; Imanaka, Tetsuji; Sakaguchi, Aya; Amano, Hikaru; Kawamura, Hidehisa; Kawamura, Hisao; Apsalikov, Kazbek N; Gusev, Boris I; Whitehead, Neil E; Shinkarev, Sergey; Hoshi, Masaharu

2008-07-01

Dolon village, located about 60 km from the border of the Semipalatinsk nuclear test site, is known to be heavily contaminated by the first USSR atomic bomb test in August 1949. Soil samples around Dolon were taken in October 2005 in an attempt to evaluate internal thyroid dose arising from incorporation of radioiodine isotopes (mainly (131)I). Iodine-129 in soil was measured by using the technique of accelerator mass spectrometry. The (129)I/(127)I atom ratios measured were in the range from 3.3 x 10(-9) to 3.3 x 10(-7). These values were within the range of the current background level ( approximately 10(-9) to 10(-7)) in the environment, including contributions from the global fallout of atmospheric nuclear tests and local fallout of nuclear facilities. The (129)I atom accumulated level in soil ranged from 1.28 x 10(13) to 1.59 x 10(14) atoms m(-2), the average (8.0 x 10(13)) of which was higher than the background level of (2-5) x 10(13). From the relationship between (129)I and( 137)Cs (corrected for background and decay from 1949 to 2005) accumulated levels, the background level of (129)I and the (129)I/(137)Cs ratio around Dolon were estimated to be (6.4 +/- 0.4) x 10(13) atoms m(-2) and 0.25 +/- 0.16, respectively. This (129)I/(137)Cs ratio is almost similar to the fission yield ratio for (239)Pu fast fission (0.24).

Geochemical characterization of soils of the eastern coast of the Northern Sakhalin Lowland

NASA Astrophysics Data System (ADS)

Zharikova, E. A.

2017-01-01

Concentrations of heavy metals (HMs) were determined in soils of the eastern coast of the Northern Sakhalin Lowland. The total contents of HMs and their distribution in the studied soils differed from those in the world soils. Thus, barium and mercury concentrations exceeded clarke values for the world soils. The reserves of mobile forms of microelements were found to be low. Significant biogenic accumulation in organic soil horizons in the process of soil formation was found for copper, arsenic, and barium.

Evaluation of consolidation characteristics of cohesive soils from piezocone penetration tests.

DOT National Transportation Integrated Search

2004-01-01

The piezocone penetration test (PCPT) has gained wide popularity and acknowledgement as a preferred in-situ device for subsurface investigation and soil characterization. The PCPT measurements can be utilized for soil identification and the evaluatio...

Spatial Distribution of Fungal Communities in an Arable Soil

PubMed Central

Moll, Julia; Hoppe, Björn; König, Stephan; Wubet, Tesfaye; Buscot, François; Krüger, Dirk

2016-01-01

Fungi are prominent drivers of ecological processes in soils, so that fungal communities across different soil ecosystems have been well investigated. However, for arable soils taxonomically resolved fine-scale studies including vertical itemization of fungal communities are still missing. Here, we combined a cloning/Sanger sequencing approach of the ITS/LSU region as marker for general fungi and of the partial SSU region for arbuscular mycorrhizal fungi (AMF) to characterize the microbiome in different maize soil habitats. Four compartments were analyzed over two annual cycles 2009 and 2010: a) ploughed soil in 0–10 cm, b) rooted soil in 40–50 cm, c) root-free soil in 60–70 cm soil depth and d) maize roots. Ascomycota was the most dominant phylum across all compartments. Fungal communities including yeasts and AMF differed strongly between compartments. Inter alia, Tetracladium, the overall largest MOTU (molecular operational taxonomic unit), occurred in all compartments, whereas Trichosporon dominated all soil compartments. Sequences belonging to unclassified Helotiales were forming the most abundant MOTUs exclusively present in roots. This study gives new insights on spatial distribution of fungi and helps to link fungal communities to specific ecological properties such as varying resources, which characterize particular niches of the heterogeneous soil environment. PMID:26840453

[Geochemical characteristics of radon and mercury in soil gas in Lhasa, Tibet, China].

PubMed

Zhou, Xiao-Cheng; Du, Jian-Guo; Wang, Chuan-Yuan; Cao, Zhong-Quan; Yi, Li; Liu, Lei

2007-03-01

The geochemical characteristics of radon and mercury in soil gas in Lhasa and vicinity are investigated based on the measurements of Rn and Hg concentrations, and environmental quality for Rn and Hg in soil gas was evaluated by means of the index of geoaccumulation. The data of Rn and Hg of 1 579 sampling site indicate that the values of environmental-geochemical background of Rn and Hg are 7 634.9 Bq/m3, 41.5 ng/m3 with standard deviations of 2.7 Bq/m3, 2.2 ng/m3, respectively. The environmental quality for Rn in soil gas is better in the west and east parts of studied area, but becomes moderate pollution (level III) in the north part of the central area. Rn is derived from radioactive elements in granitic sediments in the intermountain basin and granite base, which are the major sources of pollution. The environmental quality for Hg in soil gas becomes gradually polluted from the suburban to the center of urban, and the highest pollution reaches level IV. The background of Hg in soil gas is mainly controlled by compositions of sediments, but the Hg pollution caused by human waste and religionary use of mercury.

Screening and Characterization of Potentially Suppressive Soils against Gaeumannomyces graminis under Extensive Wheat Cropping by Chilean Indigenous Communities

PubMed Central

Durán, Paola; Jorquera, Milko; Viscardi, Sharon; Carrion, Victor J.; Mora, María de la Luz; Pozo, María J.

2017-01-01

Wheat production around the world is severely compromised by the occurrence of “take-all” disease, which is caused by the soil-borne pathogen Gaeumannomyces graminis var. tritici (Ggt). In this context, suppressive soils are those environments in which plants comparatively suffer less soil-borne pathogen diseases than expected, owing to native soil microorganism activities. In southern Chile, where 85% of the national cereal production takes place, several studies have suggested the existence of suppressive soils under extensive wheat cropping. Thus, this study aimed to screen Ggt-suppressive soil occurrence in 16 locations managed by indigenous “Mapuche” communities, using extensive wheat cropping for more than 10 years. Ggt growth inhibition in vitro screenings allowed the identification of nine putative suppressive soils. Six of these soils, including Andisols and Ultisols, were confirmed to be suppressive, since they reduced take-all disease in wheat plants growing under greenhouse conditions. Suppressiveness was lost upon soil sterilization, and recovered by adding 1% of the natural soil, hence confirming that suppressiveness was closely associated to the soil microbiome community composition. Our results demonstrate that long-term extensive wheat cropping, established by small Mapuche communities, can generate suppressive soils that can be used as effective microorganism sources for take-all disease biocontrol. Accordingly, suppressive soil identification and characterization are key steps for the development of environmentally-friendly and efficient biotechnological applications for soil-borne disease control. PMID:28861064

Characterization of extractable soil organic matter pools from African Dark Earths (AfDE): A case study in historical biochar and organic waste amendments

NASA Astrophysics Data System (ADS)

Fujiu, Manna; Plante, Alain; Ohno, Tsutomu; Solomon, Dawit; Lehmann, Johannes; Fraser, James; Leach, Melissa; Fairhead, James

2014-05-01

Anthropogenic Dark Earths are soils generated through long-term human inputs of organic and pyrogenic materials. These soils were originally discovered in the Amazon, and have since been found in Australia and in this case in Africa. African Dark Earths (AfDE) are black, highly fertile and carbon-rich soils that were formed from the original highly-weathered infertile yellowish to red Oxisols and Ultisols through an extant but hitherto overlooked climate-smart sustainable soil management system that has long been an important feature of the indigenous West African agricultural repertoire. Studies have demonstrated that ADE soils in general have significantly different organic matter properties compared to adjacent non-DE soils, largely attributable to the presence of high concentrations of ash-derived carbon. Quantification and characterization of bulk soil organic matter of several (n=11) AfDE and non-AfDE pairs of surface (0-15 cm) soils using thermal analysis techniques (TG-DSC-EGA) confirmed substantial differences in SOM composition and the presence of pyrogenic C. Such pyrogenic organic matter is generally considered recalcitrant or relatively stable, but the goal of the current study was to characterize the presumably labile, more rapidly cycling, pools of C in AfDEs through the characterization of hot water- and pyrophosphate-extractable fractions, referred to as HWEOC and PyroC respectively. Extracts were analyzed for carbon content, as well as composition using fluorescence (EEM/PARAFAC) and high resolution mass spectrometry (FTICR-MS). The amount of extractable C as a proportion of total soil C was relatively low: less than ~0.8% for HWEOC and 2.8% for PyroC. The proportion of HWEOC did not differ (P = 0.18, paired t-test) between the AfDE and the non-AfDE soils, while the proportions of PyroC were significantly larger (P = 0.001) in the AfDE soils compared to the non-AfDE soils. Preliminary analysis of the EEM/PARAFAC data suggests that AfDE samples had a greater fraction of their DOM that was more humic-like than the paired non-AfDE samples, though differences were small. Similarly, FTICR-MS analysis of hot water extracts suggests that differences among the three sites analyzed were larger than between the paired AfDE and non-AfDE extracts. Overall, in spite of substantial differences in the composition of bulk SOM, the extractable fractions appear to be relatively similar between the AfDE and non-AfDE soils.

Spatial variability structure of soil CO2 emission and soil physical and chemical properties characterized by fractal dimension in sugarcane areas

NASA Astrophysics Data System (ADS)

Bicalho, E. S.; Teixeira, D. B.; Panosso, A. R.; Perillo, L. I.; Iamaguti, J. L.; Pereira, G. T.; La Scala, N., Jr.

2012-04-01

Soil CO2 emission (FCO2) is influenced by chemical, physical and biological factors that affect the production of CO2 in the soil and its transport to the atmosphere, varying in time and space depending on environmental conditions, including the management of agricultural area. The aim of this study was to investigate the structure of spatial variability of FCO2 and soil properties by using fractal dimension (DF), derived from isotropic variograms at different scales, and construction of fractograms. The experimental area consisted of a regular grid of 60 × 60 m on sugarcane area under green management, containing 141 points spaced at minimum distances ranging from 0.5 to 10 m. Soil CO2 emission, soil temperature and soil moisture were evaluated over a period of 7 days, and soil chemical and physical properties were determined by sampling at a depth of 0.0 to 0.1 m. FCO2 showed an overall average of 1.51 µmol m-2 s-1, correlated significantly (p < 0.05) with soil physical factors such as soil bulk density, air-filled pore space, macroporosity and microporosity. Significant DF values were obtained in the characterization of FCO2 in medium and large scales (from 20 m). Variations in DF with the scale, which is the fractogram, indicate that the structure of FCO2 variability is similar to that observed for the soil temperature and total pore volume, and reverse for the other soil properties, except for macroporosity, sand content, soil organic matter, carbon stock, C/N ratio and CEC, which fractograms were not significantly correlated to the FCO2 fractogram. Thus, the structure of spatial variability for most soil properties, characterized by fractogram, presents a significant relationship with the structure of spatial variability of FCO2, generally with similar or dissimilar behavior, indicating the possibility of using the fractogram as tool to better observe the behavior of the spatial dependence of the variables along the scale.

Application of active distribute temperature sensing and fiber optic as sensors to determinate the unsaturated hydraulic conductivity curve

NASA Astrophysics Data System (ADS)

Zubelzu, Sergio; Rodriguez-Sinobas, Leonor; Sobrino, Fernando

2017-04-01

The development of methodologies for the characterization of soil water content through the use of distribute temperature sensing and fiber optic cable has allowed for modelling with high temporal and spatial accuracy water movement in soils. One of the advantage of using fiber optic as a sensor, compared with the traditional point water probes, is the possibility to measure the variable continuously along the cable every 0.125 m (up to a cable length of 1500) and every second. Traditionally, applications based on fiber optic as a soil water sensor apply the active heated fiber optic technique AHFO to follow the evolution soil water content during and after irrigation events or for hydrologic characterization. However, this paper accomplishes an original experience by using AHFO as a sensor to characterize the soil hydraulic conductivity curve in subsaturated conditions. The non lineal nature between the hidraulic conductivity curve and soil water, showing high slope in the range close to saturation ) favors the AHFO a most suitable sensor due to its ability to measure the variable at small time and length intervals. Thus, it is possible to obtain accurate and a large number of data to be used to estimate the hydraulic conductivity curve from de water flow general equation by numerical methods. Results are promising and showed the feasibility of this technique to estimate the hydraulic conductivity curve for subsaturated soils .

Integration of Magnetic and Geotechnical methods for Shallow Subsurface Soil Characterization at Sungai Batu, Kedah, Malaysia

NASA Astrophysics Data System (ADS)

Samuel, Y. M.; Saad, R.; Muztaza, N. M.; Saidin, M. M.; Muhammad, S. B.

2018-04-01

Magnetic and geotechnical methods were used for shallow subsurface soil characterization at Sungai Batu, Kedah, (Malaysia). Ground magnetic data were collected along a survey line of length 160 m long at 2 m constant station spacing, while soil drilling using hand auger was conducted at 21 m on the survey line using 0.2 m sampling interval drilled to a depth of 5 m. Result from the processed magnetic profile data shows distribution of magnetic residuals in the range of -4.55 to 1.61 nT, with magnetic low (-4.55 nT to -0.058 nT) and were identified at distances 4 m, 10 to 16 m, 20 to 26 m, 58 m, 82 m, 104 to 106 m, 118 m, and 124 to 140 m. The magnetic lows are attributes of sediments. The result from the soil drilling shows sticky samples with variable sizes, greyish to brownish / reddish in colour, and some of the samples show the presence of shiny and black spots. The characteristics of the samples suggest the soil as a by-product of completely weathered rock; weak with high water content and classified as Grade V soil. The study concludes; integration of geophysical and geotechnical methods aided in characterizing the subsurface soil at Sungai Batu. The result was correlated with previous studies and confirms the importance of integrated approach in minimising ambiguity in interpretation.

[Leaching Remediation of Copper and Lead Contaminated Lou Soil by Saponin Under Different Conditions].

PubMed

Deng, Hong-xia; Yang, Ya-li; Li, Zhen; Xu, Yan; Li, Rong-hua; Meng, Zhao-fu; Yang, Ya-ti

2015-04-01

In order to investigate the leaching remediation effect of the eco-friendly biosurfactant saponin for Cu and Pb in contaminated Lou soil, batch tests method was used to study the leaching effect of saponin solution on single Cu, Pb contaminated Lou soil and mixed Cu and Pb contaminated Lou soil under different conditions such as reaction time, mass concentration of saponin, pH, concentration of background electrolyte and leaching times. The results showed that the maximum leaching removal effect of Cu and Pb in contaminated Lou soil was achieved by complexation of the heavy metals with saponin micelle, when the mass concentration of saponin solution was 50 g x L(-1), pH was 5.0, the reaction time was 240 min, and there was no background electrolyte. In single and mixed contaminated Lou soil, the leaching percentages of Cu were 29.02% and 25.09% after a single leaching with 50 g x L(-1) saponin under optimal condition, while the single leaching percentages of Pb were 31.56% and 28.03%, respectively. The result indicated the removal efficiency of Pb was more significant than that of Cu. After 4 times of leaching, the cumulative leaching percentages of Cu reached 58.92% and 53.11%, while the cumulative leaching percentages of Pb reached 77.69% and 65.32% for single and mixed contaminated Lou soil, respectively. The fractionation results of heavy metals in soil before and after a single leaching showed that the contents of adsorbed and exchangeable Cu and Pb increased in the contaminated soil, while the carbonate-bound, organic bound and sulfide residual Cu and Pb in the contaminated Lou soil could be effectively removed by saponin.

Transport mechanisms of Silver Nanoparticles by runoff - A Flume Experiment

NASA Astrophysics Data System (ADS)

Mahdi Mahdi, Karrar NM; Commelin, Meindert; Peters, Ruud J. B.; Baartman, Jantiene E. M.; Ritsema, Coen; Geissen, Violette

2017-04-01

Silver Nanoparticles (AgNPs) are being used in many products as it has unique antimicrobial-biocidal properties. Through leaching, these particles will reach the soil environment which may affect soil organisms and disrupt plants. This work aims to study the potential transport of AgNPs with water and sediment over the soil surface due to soil erosion by water. This was done in a laboratory setting, using a rainfall simulator and flume. Low AgNPs concentration (50 μg.kg-1) was applied to two soil-flumes with slopes of 20% and 10%. The rainfall was applied in four events of 15 min each with the total amount of rainfall was 15mm in each event. After applying the rainfall, different samples were collected; soil clusters, background (BS) and surface sediments (Sf), from the flume surface, and, Runoff sediments (RS) and water (RW) was collected from the outlet. The results showed that AgNPs were detected in all samples collected, however, AgNPs concentration varied according samples type (soil or water), time of collection (for runoff water and sediment) and the slope of the soil flume. Further, the higher AgNPs concentrations were detected in the background soil (BS); as the BS samples have more finer parts (silt and clay). The AgNPs concentration in the runoff sediments increased with subsequent applied rain events. In addition to that, increasing the slope of the flume from 10% to 20% increased the total AgNPs transported with the runoff sediments by a factor 1.5. The study confirms that AgNPs can be transported over the soil surface by both runoff water and sediments due to erosion.

Non-Invasive Methods to Characterize Soil-Plant Interactions at Different Scales

NASA Astrophysics Data System (ADS)

Javaux, M.; Kemna, A.; Muench, M.; Oberdoerster, C.; Pohlmeier, A.; Vanderborght, J.; Vereecken, H.

2006-05-01

Root water uptake is a dynamic and non-linear process, which interacts with the soil natural variability and boundary conditions to generate heterogeneous spatial distributions of soil water. Soil-root fluxes are spatially variable due to heterogeneous gradients and hydraulic connections between soil and roots. While 1-D effective representation of the root water uptake has been successfully applied to predict transpiration and average water content profiles, finer spatial characterization of the water distribution may be needed when dealing with solute transport. Indeed, root water uptake affects the water velocity field, which has an effect on solute velocity and dispersion. Although this variability originates from small-scale processes, these may still play an important role at larger scales. Therefore, in addition to investigate the variability of the soil hydraulic properties, experimental and numerical tools for characterizing root water uptake (and its effects on soil water distribution) from the pore to the field scales are needed to predict in a proper way the solute transport. Obviously, non-invasive and modeling techniques which are helpful to achieve this objective will evolve with the scale of interest. At the pore scale, soil structure and root-soil interface phenomena have to be investigated to understand the interactions between soil and roots. Magnetic resonance imaging may help to monitor water gradients and water content changes around roots while spectral induced polarization techniques may be used to characterize the structure of the pore space. At the column scale, complete root architecture of small plants and water content depletion around roots can be imaged by magnetic resonance. At that scale, models should explicitly take into account the three-dimensional gradient dependency of the root water uptake, to be able to predict solute transport. At larger scales however, simplified models, which implicitly take into account the heterogeneous root water uptake along roots, should be preferred given the complexity of the system. At such scales, electrical resistance tomography or ground-penetrating radar can be used to map the water content changes and derive effective parameters for predicting solute transport.

Identifying key soil cyanobacteria easy to isolate and culture for arid soil restoration

NASA Astrophysics Data System (ADS)

Roncero-Ramos, Beatriz; Ángeles Muñoz-Martín, M.; Chamizo, Sonia; Román, Raúl; Rodriguez-Caballero, Emilio; Mateo, Pilar; Cantón, Yolanda

2017-04-01

Drylands represent an important fraction of the Earth land's surface. Low cover of vascular plants characterizes these regions, and the large open areas among plants are often colonized by cyanobacteria, mosses, lichens, algae, bryophytes, bacteria and fungi, known as biocrusts. Because these communities are on or within the soil surface, they contribute to improve physicochemical properties of the uppermost soil layers and have important effects on soil fertility and stability, so they could play an important role on soil restoration. Cyanobacteria appear to be a cross component of biocrusts and they have been demonstrated to enhance water availability, soil fertility (fixing atmospheric C and N), and soil aggregation (thanks to their filamentous morphology and the exopolysaccharides they excrete), and significantly reduce water and wind erosion. Besides, they are able to tolerate high temperatures and UV radiation. All these features convert cyanobacteria in pioneer organisms capable of colonizing degraded soils and may be crucial in facilitating the succession of more developed organisms such as vascular plants. Therefore, the use of native cyanobacteria, already adapted to site environmental conditions, could guarantee a successful restoration approach of degraded soils. However, previous to their application for soil restoration, the most representative species inhabiting these soils should be identified. The objective of this study was to identify (morphologically and genetically) and isolate representative native cyanobacteria species from arid soils in SE Spain, characterized for being easily isolated and cultured with the aim of using them to inoculate degraded arid soil. We selected two study areas in Almería, SE Spain, where biocrust cover most of the open spaces between plants: El Cautivo experimental site located in the Tabernas desert and a limestone quarry located at the southeastern edge of the Gádor massif. The first site is characterized by scarcely developed soils with low thickness, poor structure and low organic matter content, while soils in the second site present high degradation due to human activities. Cyanobacterial biocrust at different developmental stages were collected and maintained in the laboratory under dry and dark conditions until they were processed. Different culture media, with and without N, were used to isolate single trichomes, in order to have representatives of N fixing and non-fixing cyanobacteria. The isolated strains were morphological and genetically characterized by sequencing the 16S rRNA gene and phylogenetic analyses. Results from cultures of several soil samples with different media show that the most representative soil cyanobacteria genera in these areas and easiest to maintain under laboratory conditions were: Scytonema, Tolypothrix, Leptolyngbya and Trichocoleus from the El Cautivo experimental site; and Nostoc, Tolypothrix and Leptolyngbya from the limestone quarry. In this study, we present a description of some of the cyanobacteria colonizing biocrust in these area, which are easy to be isolated and cultured under laboratory conditions, as a previous step to design a restoration method for their inoculation on degraded soils.

Littoral assessment of mine burial signatures (LAMBS): buried landmine/background spectral-signature analyses

NASA Astrophysics Data System (ADS)

Kenton, Arthur C.; Geci, Duane M.; Ray, Kristofer J.; Thomas, Clayton M.; Salisbury, John W.; Mars, John C.; Crowley, James K.; Witherspoon, Ned H.; Holloway, John H., Jr.

2004-09-01

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies (ALRT) project's LAMBS effort is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 μm) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. LAMBS has expanded previously collected databases to littoral areas - primarily dry and wet sandy soils - where tidal, surf, and wind conditions can severely modify spectral signatures. At AeroSense 2003, we reported completion of three buried mine collections at an inland bay, Atlantic and Gulf of Mexico beach sites. We now report LAMBS spectral database analyses results using metrics which characterize the detection performance of general types of spectral detection algorithms. These metrics include mean contrast, spectral signal-to-clutter, covariance, information content, and spectral matched filter analyses. Detection performance of the buried land mines was analyzed with regard to burial age, background type, and environmental conditions. These analyses considered features observed due to particle size differences, surface roughness, surface moisture, and compositional differences.

Littoral Assessment of Mine Burial Signatures (LAMBS) buried land mine/background spectral signature analyses

USGS Publications Warehouse

Kenton, A.C.; Geci, D.M.; Ray, K.J.; Thomas, C.M.; Salisbury, J.W.; Mars, J.C.; Crowley, J.K.; Witherspoon, N.H.; Holloway, J.H.; Harmon R.S.Broach J.T.Holloway, Jr. J.H.

2004-01-01

The objective of the Office of Naval Research (ONR) Rapid Overt Reconnaissance (ROR) program and the Airborne Littoral Reconnaissance Technologies (ALRT) project's LAMBS effort is to determine if electro-optical spectral discriminants exist that are useful for the detection of land mines in littoral regions. Statistically significant buried mine overburden and background signature data were collected over a wide spectral range (0.35 to 14 ??m) to identify robust spectral features that might serve as discriminants for new airborne sensor concepts. LAMBS has expanded previously collected databases to littoral areas - primarily dry and wet sandy soils - where tidal, surf, and wind conditions can severely modify spectral signatures. At AeroSense 2003, we reported completion of three buried mine collections at an inland bay, Atlantic and Gulf of Mexico beach sites.1 We now report LAMBS spectral database analyses results using metrics which characterize the detection performance of general types of spectral detection algorithms. These metrics include mean contrast, spectral signal-to-clutter, covariance, information content, and spectral matched filter analyses. Detection performance of the buried land mines was analyzed with regard to burial age, background type, and environmental conditions. These analyses considered features observed due to particle size differences, surface roughness, surface moisture, and compositional differences.

FIELD EVALUATION OF IN-SITU TREATMENTS TO REDUCE SOIL-LEAD BIOAVAILABILITY: INTRODUCTION & BACKGROUND

EPA Science Inventory

The In-place Inactivation and Natural Ecological Restoration Technologies (IINERT) Soil-Metals Action Team was established in 11/95 as one of several Action Teams under the USEPA Remediation Technologies Development Forum (RTDF). Its primary goal was to examine in situ remediatio...

Comparative characterization of sewage sludge compost and soil: Heavy metal leaching characteristics.

PubMed

Fang, Wen; Wei, Yonghong; Liu, Jianguo

2016-06-05

The leaching and accumulation of heavy metals are major concerns following the land application of sewage sludge compost (SSC). We comparatively characterized SSC, the reference soil, and the SSC amended soil to investigate their similarities and differences regarding heavy metal leaching behavior and then to evaluate the effect of SSC land application on the leaching behavior of soil. Results showed that organic matter, including both of particulate organic matter (POM) and dissolved organic matter (DOM), were critical factors influencing heavy metal leaching from both of SSC and the soil. When SSC was applied to soil at the application rate of 48t/ha, the increase of DOM content slightly enhanced heavy metal leaching from the amended soil over the applicable pH domain (6

Tungsten Speciation and Solubility in Munitions-Impacted Soils.

PubMed

Bostick, Benjamín C; Sun, Jing; Landis, Joshua D; Clausen, Jay L

2018-02-06

Considerable questions persist regarding tungsten geochemistry in natural systems, including which forms of tungsten are found in soils and how adsorption regulates dissolved tungsten concentrations. In this study, we examine tungsten speciation and solubility in a series of soils at firing ranges in which tungsten rounds were used. The metallic, mineral, and adsorbed forms of tungsten were characterized using X-ray absorption spectroscopy and X-ray microprobe, and desorption isotherms for tungsten in these soils were used to characterize its solid-solution partitioning behavior. Data revealed the complete and rapid oxidation of tungsten metal to hexavalent tungsten(VI) and the prevalence of adsorbed polymeric tungstates in the soils rather than discrete mineral phases. These polymeric complexes were only weakly retained in the soils, and porewaters in equilibrium with contaminated soils had 850 mg L -1 tungsten, considerably in excess of predicted solubility. We attribute the high solubility and limited adsorption of tungsten to the formation of polyoxometalates such as W 12 SiO 40 4- , an α-Keggin cluster, in soil solutions. Although more research is needed to confirm which of such polyoxometalates are present in soils, their formation may not only increase the solubility of tungsten but also facilitate its transport and influence its toxicity.

DNAPL Managements Overview

DTIC Science & Technology

2007-04-01

characterizing groundwater contamination, In: Contaminated Soil (ConSoil), Thomas Telford, Leipzig, Germany , pp. 198-205. Rao, P.S.C. and J.W. Jawitz, 2003...installed to contain contamination, Keens Creek was rerouted to avoid passage through the contaminated site, new trees for phytoremediation and soil

BIOAVAILABILITY OF METALS IN ENVIRONMENTAL MEDIA

EPA Science Inventory

Heavy metal and organic chemical contamination of soils is a worldwide problem posing a risk to humans and more directly, soil organisms. Due to widespread metal contamination, it is necessary to characterize soils suspected of metal contamination and determine if the metal le...

Characterization of labile organic carbon in coastal wetland soils of the Mississippi River deltaic plain: relationships to carbon functionalities.

PubMed

Dodla, Syam K; Wang, Jim J; Delaune, Ronald D

2012-10-01

Adequate characterization of labile organic carbon (LOC) is essential to the understanding of C cycling in soil. There has been very little evaluation about the nature of LOC characterizations in coastal wetlands, where soils are constantly influenced by different redox fluctuations and salt water intrusions. In this study, we characterized and compared LOC fractions in coastal wetland soils of the Mississippi River deltaic plain using four different methods including 1) aerobically mineralizable C (AMC), 2) cold water extractable C (CWEC), 3) hot water extractable C (HWEC), and 4) salt extractable C (SEC), as well as acid hydrolysable C (AHC) which includes both labile and slowly degradable organic C. Molecular organic C functional groups of these wetland soils were characterized by (13)C solid-state nuclear magnetic resonance (NMR). The LOC and AHC increased with soil organic C (SOC) regardless of wetland soil type. The LOC estimates by four different methods were positively and significantly linearly related to each other (R(2)=0.62-0.84) and with AHC (R(2)=0.47-0.71). The various LOC fractions accounted for ≤4.3% of SOC whereas AHC fraction represented 16-49% of SOC. AMC was influenced positively by O/N-alkyl and carboxyl C but negatively by alkyl C, whereas CWEC and SEC fractions were influenced only positively by carboxyl C but negatively by alkyl C in SOC. On the other hand, HWEC fraction was found to be only influenced positively by carbonyl C, and AHC positively by O/N-alkyl and alkyl C but negatively by aromatic C groups in SOC. Overall these relations suggested different contributions of various molecular organic C moieties to LOC in these wetlands from those often found for upland soils. The presence of more than 50% non-acid hydrolysable C suggested the dominance of relatively stable SOC pool that would be sequestered in these Mississippi River deltaic plain coastal wetland soils. The results have important implications to the understanding of the liability and refractory character of SOC in these wetlands as recent studies suggest marsh SOC to be an important C source in fueling hypoxia in the northern Gulf of Mexico. Copyright © 2012 Elsevier B.V. All rights reserved.

Method for detecting moisture in soils using secondary cosmic radiation

DOEpatents

Condreva, Kenneth

2003-12-16

Water content in a soil is determined by measuring the attenuation of secondary background cosmic radiation as this radiation propagates through a layer of soil and water. By measuring the attenuation of secondary cosmic radiation in the range of 5 MeV-15 MeV it is possible to obtain a relative measure of the water content in a soil layer above a suitable radiation detector and thus establish when and how much irrigation is needed. The electronic circuitry is designed so that a battery pack can be used to supply power.

MOBILIZATION OF ENDOCRINE DISRUPTING CHEMICALS AND ESTROGENIC ACTIVITY IN SIMULATED RAINFALL RUNOFF FROM LAND-APPLIED BIOSOLIDS

PubMed Central

Giudice, Ben D.; Young, Thomas M.

2012-01-01

Municipal biosolids are commonly applied to land as soil amendment or fertilizer as a form of beneficial reuse of what could otherwise be viewed as waste. Balanced against this benefit are potential risks to groundwater and surface water quality from constituents that may be mobilized during storm events. The objective of the present study was to characterize the mobilization of selected endocrine disrupting compounds (EDCs), heavy metals, and total estrogenic activity in rainfall runoff from land-applied biosolids. Rainfall simulations were conducted on soil plots amended with biosolids. Surface runoff and leachate was collected and analyzed for the EDCs bisphenol A, 17α-ethynylestradiol, triclocarban, triclosan, octylphenol, and nonylphenol; a suite of sixteen metals; and estrogenic activity via the ER-CALUX bioassay. Triclocarban (2.3–17.3 ng/L), triclosan (<51–309 ng/L), and octylphenol (<4.9–203 ng/L) were commonly detected. Chromium (2.0–22 µg/L), cobalt (2.5–10 µg/L), nickel (28–235 µg/L), copper (14–110 µg/L), arsenic (1.2–2.7 µg/L), and selenium (0.29–12 µg/L) were quantifiable over background levels. Triclosan, nickel, and copper were detected at levels that might pose some risk to aquatic life, though levels of metals in the biosolids were well below maximum allowable regulatory limits. ER-CALUX results were mostly explained by background bisphenol A contamination and octylphenol in runoff, though unknown contributors and/or matrix effects were also found. PMID:21786314

Mobilization of endocrine-disrupting chemicals and estrogenic activity in simulated rainfall runoff from land-applied biosolids.

PubMed

Giudice, Ben D; Young, Thomas M

2011-10-01

Municipal biosolids are commonly applied to land as soil amendment or fertilizer as a form of beneficial reuse of what could otherwise be viewed as waste. Balanced against this benefit are potential risks to groundwater and surface water quality from constituents that may be mobilized during storm events. The objective of the present study was to characterize the mobilization of selected endocrine-disrupting compounds, heavy metals, and total estrogenic activity in rainfall runoff from land-applied biosolids. Rainfall simulations were conducted on soil plots amended with biosolids. Surface runoff and leachate was collected and analyzed for the endocrine-disrupting compounds bisphenol A, 17α-ethynylestradiol, triclocarban, triclosan, octylphenol, and nonylphenol; a suite of 16 metals; and estrogenic activity via the estrogen receptor-mediated chemical activated luciferase gene expression (ER-CALUX) bioassay. Triclocarban (2.3-17.3 ng/L), triclosan (<51-309 ng/L), and octylphenol (<4.9-203 ng/L) were commonly detected. Chromium (2.0-22 µg/L), Co (2.5-10 µg/L), Ni (28-235 µg/L), Cu (14-110 µg/L), As (1.2-2.7 µg/L), and Se (0.29-12 µg/L) were quantifiable over background levels. Triclosan, Ni, and Cu were detected at levels that might pose some risk to aquatic life, though levels of metals in the biosolids were well below the maximum allowable regulatory limits. The ER-CALUX results were mostly explained by background bisphenol A contamination and octylphenol in runoff, although unknown contributors or matrix effects were also found. Copyright © 2011 SETAC.

Use of carborne measured gamma-ray K/Th ratio for estimation of texture at different field sites across Europe

NASA Astrophysics Data System (ADS)

Dierke, C.; Werban, U.; Dietrich, P.

2011-12-01

In the past gamma-ray measurements were used for geological survey from aircraft and in borehole logging for deposit exploration and geological survey. For these applications the relationships between the physical measured parameter - the concentration of natural gamma emitter 40K, 238U and 232Th - and geological origin or sedimentary developments are described well. Based on these applications and knowledge in combination with adjusted sensor systems, gamma-ray measurements seem to be also a useful and fast tool for soil characterization. The measured isotope concentration in soils depends on different soil parameters, which are the result of composition and properties of parent rock and processes during soil geneses under different climatic conditions. Grain size distribution, type of clay minerals and organic matter are soil parameters which influence the gamma-ray concentration directly. Many applications of gamma-ray measurements for soil characterisation and digital soil mapping (DSM) are known from e.g. Australia and during the last years there are attempts to use that method in Europe as well. One main influencing factor for nuclide concentration in soils is the grain size. Megumi (1977) found with decreasing particle size an increase in nuclide concentration, which can be explained by higher specific surface and resulting higher surface adsorption for smaller particles. We did systematic measurements at different field sites across Central Europe to investigate the relationship between concentration of gamma emitter and the grain size distribution of top soil. For the measurements we choose field sites with different pedogenesis and range in clay content. For survey we used a 4l NaI(Tl) detector, which is mounted on a sledge an can be towed by a four-wheel-vehicle across the agricultural used field sites. The measured nuclide concentrations were compared with grain size distribution data of fine soil (< 2 mm). For interpretation we used single nuclide concentrations as well as K/Th ratios. The results show site specific relationships depending on pedogenesis and geological background. With this knowledge it is possible to develop a more regional approach for γ-ray interpretation. Our studies are a basis to enhance physical understanding of the measured data at landscape scale across Europe. These activities are done within the iSOIL project. iSOIL- Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment; iSOIL is one member of the SOIL TECHNOLOGY CLUSTER of Research Projects funded by the EC. Megumi, K. and T. Mamuro (1977). "Concentration Of Uranium Series Nuclides In Soil Particles In Relation To Their Size." Journal Of Geophysical Research 82(2): 353-356.

Air-surface exchange measurements of gaseous elemental mercury over naturally enriched and background terrestrial landscapes in Australia

NASA Astrophysics Data System (ADS)

Edwards, G. C.; Howard, D. A.

2013-05-01

This paper presents the first gaseous elemental mercury (GEM) air-surface exchange measurements obtained over naturally enriched and background (<0.1 μg g-1 Hg) terrestrial landscapes in Australia. Two pilot field studies were carried out during the Australian autumn and winter periods at a copper-gold-cobalt-arsenic-mercury mineral field near Pulganbar, NSW. GEM fluxes using a dynamic flux chamber approach were measured, along with controlling environmental parameters over three naturally enriched and three background substrates. The enriched sites results showed net emission to the atmosphere and a strong correlation between flux and substrate Hg concentration, with average fluxes ranging from 14 ± 1 ng m-2 h-1 to 113 ± 6 ng m-2 h-1. Measurements at background sites showed both emission and deposition. The average Hg flux from all background sites showed an overall net emission of 0.36 ± 0.06 ng m-2 h-1. Fluxes show strong relationships with temperature, radiation, and substrate parameters. A compensation point of 2.48, representative of bare soils was determined. For periods of deposition, dry deposition velocities ranged from 0.00025 cm s-1 to 0.0083 cm s-1 with an average of 0.0041 ± 0.00018 cm s-1, representing bare soil, nighttime conditions. Comparison of the Australian data to North American data suggests the need for Australian-specific mercury air-surface exchange data representative of Australia's unique climatic conditions, vegetation types, land use patterns and soils.

Paloma-radon: Atmospheric radon-222 as a geochemical probe for water in the Martian subsoil.

NASA Astrophysics Data System (ADS)

Sabroux, J.-C.; Michielsen, N.; Voisin, V.; Ferry, C.; Richon, P.; Pineau, J.-F.; Le Roulley, J.-C.; Chassefière, E.

2003-04-01

Radon exhalation from a porous soil is known to depend strongly on the soil moisture content: a minute amount of water, or water ice, in the pore space increases dramatically the possibility for radon to migrate far from its parent mineral. We propose to take advantage of this characteristic by using atmospheric radon-222 as a geochemical probe for water in the Martian soil, at least one order of magnitude deeper than the current Mars Odyssey neutron data. Strong thermal inversions during the Martian night will accumulate radon in the lowest atmospheric boundary layer, up to measurable levels despite the comparatively high environmental (cosmic and solar) background radiation and the assumed low uranium content of the upper crust of the planet. Preliminary studies and development of an instrument for the measurement of the Martian atmospheric alpha radioactivity is part of the CNES-supported PALOMA experiment. Two test benches have been implemented, one of them allowing differential measurements of the diffusion of radon in the Martian soil simulant NASA JSC Mars-1, under relevant temperatures and pressures. The other, a 1 m^3 radon-dedicated test bench, aims to characterize the instrument that will measure radon in the Mars environment (7 mb CO_2). Tests on several nuclear radiation detectors show that semiconductor alpha-particle detectors (PIPS) are the best option (already on board the Mars Pathfinder Rover and other platforms). In addition, the detection volume is left open in order to capitalize upon the long (ca. 4 m) alpha track at this low pressure. A stationary diffusion model was developed in order to assess the radon flux at the Mars soil surface. Diffusion of gas in Martian soil is governed by Knudsen diffusion. The radon Knudsen diffusion coefficient was estimated, depending on the soil moisture and relevant structural properties, leading to a radon diffusion length of the order of 20 m. The landed platform PALOMA-Radon instrument will consist of a set of alpha detectors connected to an electronic spectrometer, a system of collimators and an alpha source used for test and calibration purposes.

Event- and site-specific soil wetting and seasonal change in amount of soil water

USDA-ARS?s Scientific Manuscript database

Numerous studies have examined ways to characterize the central tendency of soil water within a field or watershed. Extreme changes in water content reveal more about water movement within the area. The purpose of this study was to determine if extreme soil water changes varied among sites, and to s...

Spatial distribrrtion of soil carbon in southern New England hardwood forest landscapes

Treesearch

Aletta A. Davis; Mark H. Stolt; Jana E. Compton

2004-01-01

Understanding soil organic C (SOC) spatial variability is critical when developing C budgets, explaining the cause and effects of climate change, and for basic ecosystem characterization. We investigated delineations of four soil series to elucidate teh factors that affect the size, distribution, and varibility of SOC pools from horizon to landscape scales. These soils...

Mapping of hydropedologic spatial patterns in a steep headwater catchment

Treesearch

Cody P. Gillin; Scott W. Bailey; Kevin J. McGuire; John P. Gannon

2015-01-01

A hydropedologic approach can be used to describe soil units affected by distinct hydrologic regimes. We used field observations of soil morphology and geospatial information technology to map the distribution of five hydropedologic soil units across a 42-ha forested headwater catchment. Soils were described and characterized at 172 locations within Watershed 3, the...

Timber Harvesting Effects on Spatial Variability of Southeastern U.S. Piedmont Soil Properties

Treesearch

J.N. Shaw; Emily A. Carter

2002-01-01

Site-specific forestry requires detailed characterization of the spatial distribution of forest soil properties and the magnitude of harvesting impacts in order to prescribe appropriate management schemes. Furthermore, evaluation of the effects of timber harvesting on soil properties conducted on a landscape scale improves the interpretive value of soil survey data....

Description of the Fork Mountain long-term soil productivity study: site characterization

Treesearch

Mary Beth Adams; James Burger; Lucian Zelazny; John Baumgras

2004-01-01

The effects of air pollution and timber harvesting on soil resources continue to be an important issue in eastern hardwood forests. This publication describes the Fork Mountain Long-term Soil Productivity Study (LTSP), located on the Fernow Experimental Forest, WV, and the pretreatment stand, soil and climatic conditions. Extensive vegetation surveys, biomass...

Sensitivity of the normalized difference vegetation index to subpixel canopy cover, soil albedo, and pixel scale

NASA Technical Reports Server (NTRS)

Jasinski, Michael F.

1990-01-01

An analytical framework is provided for examining the physically based behavior of the normalized difference vegetation index (NDVI) in terms of the variability in bulk subpixel landscape components and with respect to variations in pixel scales, within the context of the stochastic-geometric canopy reflectance model. Analysis focuses on regional scale variability in horizontal plant density and soil background reflectance distribution. Modeling is generalized to different plant geometries and solar angles through the use of the nondimensional solar-geometric similarity parameter. Results demonstrate that, for Poisson-distributed plants and for one deterministic distribution, NDVI increases with increasing subpixel fractional canopy amount, decreasing soil background reflectance, and increasing shadows, at least within the limitations of the geometric reflectance model. The NDVI of a pecan orchard and a juniper landscape is presented and discussed.

[The status of soil contamination in areas of northern and northwestern Bohemia affected by pollution].

PubMed

Podlesáková, E; Nĕmecek, J; Vácha, R

1999-10-20

A regional study of soil contamination in North and Northwest immission-impacted Bohemian regions present the results of the assessment of soil loads of agricultural soils by hazardous trace elements and organic xenobiotic substances. The evaluation is based on the exceeding of background values of contaminants (upper limit of their variability). Two forms of soil loads by trace elements are differentiated, the anthropogenic and geogenic one. They occur simultaneously on the territory under study. Geogenic "loads" prevail (basalts, metallogenic zones). Anthropogenic contamination by both hazardous elements and organic xenobiotic substances occurs only in some parts of these severely immission-impacted regions.

Climate and edaphic controllers influence rhizosphere community assembly for a wild annual grass

DOE PAGES

Nuccio, Erin E.; Anderson-Furgeson, James; Estera, Katerina Y.; ...

2016-05-09

The interface between roots and soil, known as the rhizosphere, is a dynamic habitat in the soil ecosystem. Unraveling the factors that control rhizosphere community assembly is a key starting point for understanding the diversity of plant-microbial interactions that occur in soil. The goals of this study were to determine how environmental factors shape rhizosphere microbial communities, such as local soil characteristics and the regional climate, and to determine the relative influence of the rhizosphere on microbial community assembly compared to the pressures imposed by the local and regional environment. We identified the bacteria present in the soil immediately adjacentmore » to the roots of wild oat (Avena spp.) in three California grasslands using deep Illumina 16S sequencing. Rhizosphere communities were more similar to each other than to the surrounding soil communities from which they were derived, despite the fact that the grasslands studied were separated by hundreds of kilometers. The rhizosphere was the dominant factor structuring bacterial community composition (38% variance explained), and was comparable in magnitude to the combined local and regional effects (22% and 21%, respectively). Rhizosphere communities were most influenced by factors related to the regional climate (soil moisture and temperature), while background soil communities were more influenced by soil characteristics (pH, CEC, exchangeable cations, clay content). The Avena core microbiome was strongly phylogenetically clustered according to the metrics NRI and NTI, which indicates that selective processes likely shaped these communities. Furthermore, 17% of these taxa were not detectable in the background soil, even with a robust sequencing depth of approximately 70,000 sequences per sample. In conclusion, these results support the hypothesis that roots select less abundant or possibly rare populations in the soil microbial community, which appear to be lineages of bacteria that have made a physiological tradeoff for rhizosphere competence at the expense of their competitiveness in non-rhizosphere soil.« less

Climate and edaphic controllers influence rhizosphere community assembly for a wild annual grass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nuccio, Erin E.; Anderson-Furgeson, James; Estera, Katerina Y.

The interface between roots and soil, known as the rhizosphere, is a dynamic habitat in the soil ecosystem. Unraveling the factors that control rhizosphere community assembly is a key starting point for understanding the diversity of plant-microbial interactions that occur in soil. The goals of this study were to determine how environmental factors shape rhizosphere microbial communities, such as local soil characteristics and the regional climate, and to determine the relative influence of the rhizosphere on microbial community assembly compared to the pressures imposed by the local and regional environment. We identified the bacteria present in the soil immediately adjacentmore » to the roots of wild oat (Avena spp.) in three California grasslands using deep Illumina 16S sequencing. Rhizosphere communities were more similar to each other than to the surrounding soil communities from which they were derived, despite the fact that the grasslands studied were separated by hundreds of kilometers. The rhizosphere was the dominant factor structuring bacterial community composition (38% variance explained), and was comparable in magnitude to the combined local and regional effects (22% and 21%, respectively). Rhizosphere communities were most influenced by factors related to the regional climate (soil moisture and temperature), while background soil communities were more influenced by soil characteristics (pH, CEC, exchangeable cations, clay content). The Avena core microbiome was strongly phylogenetically clustered according to the metrics NRI and NTI, which indicates that selective processes likely shaped these communities. Furthermore, 17% of these taxa were not detectable in the background soil, even with a robust sequencing depth of approximately 70,000 sequences per sample. In conclusion, these results support the hypothesis that roots select less abundant or possibly rare populations in the soil microbial community, which appear to be lineages of bacteria that have made a physiological tradeoff for rhizosphere competence at the expense of their competitiveness in non-rhizosphere soil.« less

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico

PubMed Central

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-01-01

Determining ionizing radiation in a geographic area serves to assess its effects on a population’s health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h−1. At the same sites, 48 soil samples were taken to obtain the activity concentrations of 226Ra, 232Th and 40K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h−1. Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg−1, for 226Ra, 232Th and 40K, respectively. From the analysis, the spatial distribution of 232Th, 226Ra and 40K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize. PMID:26437425

Lifetime Effective Dose Assessment Based on Background Outdoor Gamma Exposure in Chihuahua City, Mexico.

PubMed

Luevano-Gurrola, Sergio; Perez-Tapia, Angelica; Pinedo-Alvarez, Carmelo; Carrillo-Flores, Jorge; Montero-Cabrera, Maria Elena; Renteria-Villalobos, Marusia

2015-09-30

Determining ionizing radiation in a geographic area serves to assess its effects on a population's health. The aim of this study was to evaluate the spatial distribution of the background environmental outdoor gamma dose rates in Chihuahua City. This study also estimated the annual effective dose and the lifetime cancer risks of the population of this city. To determine the outdoor gamma dose rate in air, the annual effective dose and the lifetime cancer risk, 48 sampling points were randomly selected in Chihuahua City. Outdoor gamma dose rate measurements were carried out by using a Geiger-Müller counter. Outdoor gamma dose rates ranged from 113 to 310 nGy·h(-1). At the same sites, 48 soil samples were taken to obtain the activity concentrations of (226)Ra, (232)Th and (40)K and to calculate their terrestrial gamma dose rates. Radioisotope activity concentrations were determined by gamma spectrometry. Calculated gamma dose rates ranged from 56 to 193 nGy·h(-1). Results indicated that the lifetime effective dose of the inhabitants of Chihuahua City is on average 19.8 mSv, resulting in a lifetime cancer risk of 0.001. In addition, the mean of the activity concentrations in soil were 52, 73 and 1097 Bq·kg(-1), for (226)Ra, (232)Th and (40)K, respectively. From the analysis, the spatial distribution of (232)Th, (226)Ra and (40)K is to the north, to the north-center and to the south of city, respectively. In conclusion, the natural background gamma dose received by the inhabitants of Chihuahua City is high and mainly due to the geological characteristics of the zone. From the radiological point of view, this kind of study allows us to identify the importance of manmade environments, which are often highly variable and difficult to characterize.

Polyoxyethylene Tallow Amine, a Glyphosate Formulation Adjuvant: Soil Adsorption Characteristics, Degradation Profile, and Occurrence on Selected Soils from Agricultural Fields in Iowa, Illinois, Indiana, Kansas, Mississippi, and Missouri.

PubMed

Tush, Daniel; Meyer, Michael T

2016-06-07

Polyoxyethylene tallow amine (POEA) is an inert ingredient added to formulations of glyphosate, the most widely applied agricultural herbicide. POEA has been shown to have toxic effects to some aquatic organisms making the potential transport of POEA from the application site into the environment an important concern. This study characterized the adsorption of POEA to soils and assessed its occurrence and homologue distribution in agricultural soils from six states. Adsorption experiments of POEA to selected soils showed that POEA adsorbed much stronger than glyphosate; calcium chloride increased the binding of POEA; and the binding of POEA was stronger in low pH conditions. POEA was detected on a soil sample from an agricultural field near Lawrence, Kansas, but with a loss of homologues that contain alkenes. POEA was also detected on soil samples collected between February and early March from corn and soybean fields from ten different sites in five other states (Iowa, Illinois, Indiana, Missouri, Mississippi). This is the first study to characterize the adsorption of POEA to soil, the potential widespread occurrence of POEA on agricultural soils, and the persistence of the POEA homologues on agricultural soils into the following growing season.

Polyoxyethylene tallow amine, a glyphosate formulation adjuvant: Soil adsorption characteristics, degradation profile, and occurrence on selected soils from agricultural fields in Iowa, Illinois, Indiana, Kansas, Mississippi, and Missouri

USGS Publications Warehouse

Tush, Daniel L.; Meyer, Michael T.

2016-01-01

Polyoxyethylene tallow amine (POEA) is an inert ingredient added to formulations of glyphosate, the most widely applied agricultural herbicide. POEA has been shown to have toxic effects to some aquatic organisms making the potential transport of POEA from the application site into the environment an important concern. This study characterized the adsorption of POEA to soils and assessed its occurrence and homologue distribution in agricultural soils from six states. Adsorption experiments of POEA to selected soils showed that POEA adsorbed much stronger than glyphosate; calcium chloride increased the binding of POEA; and the binding of POEA was stronger in low pH conditions. POEA was detected on a soil sample from an agricultural field near Lawrence, Kansas, but with a loss of homologues that contain alkenes. POEA was also detected on soil samples collected between February and early March from corn and soybean fields from ten different sites in five other states (Iowa, Illinois, Indiana, Missouri, Mississippi). This is the first study to characterize the adsorption of POEA to soil, the potential widespread occurrence of POEA on agricultural soils, and the persistence of the POEA homologues on agricultural soils into the following growing season.

Probabilistic Modeling of Childhood Multimedia Lead Exposures: Examining the Soil Ingestion Pathway

EPA Science Inventory

BACKGROUND: Drinking water and other sources for lead are the subject of public health concerns around the Flint, Michigan, drinking water and East Chicago, Indiana, lead in soil crises. In 2015, the U.S. Environmental Protection Agency (EPA)’s National Drinking Water Advis...

Visualizing and quantifying microtopographic change of dryland landscapes from an unmanned aircraft system

USDA-ARS?s Scientific Manuscript database

Background/Question/Methods: Soil and site stability are key attributes of assessing the health of dryland landscapes because these lands are susceptible to high rates of wind- and water-caused erosion. Field techniques for measuring and monitoring soil erosion in drylands are often labor intensive...

Diagnostic Examination for Students Entering Graduate Study in Soil Science.

ERIC Educational Resources Information Center

Loynachan, T. E.

1988-01-01

Reports that students with soil science background performed better on a diagnostic examination; no relationship existed between exam performance and country of origin, degree sought, or undergraduate class quartile. Concludes that exam results, the grade received in a beginning graduate-level course and the cumulative graduate grade-point average…

Fumigation efficacy and emission reduction using low-permeability film in orchard soil fumigation

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Many orchards in California, USA, apply fumigants to soil before replanting to reduce the impact of pest pressure or replanting disease on new tree establishment. Emission control of alternative fumigants to methyl bromide is mandatory in air quality (ozone) non-attainment areas. This s...

Biogeochemistry of hydrothermally and adjacent non-altered soils

USDA-ARS?s Scientific Manuscript database

As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

A global spectral library to characterize the world's soil

USDA-ARS?s Scientific Manuscript database

Soil provides ecosystem services, supports human health and habitation, stores carbon and regulates emissions of greenhouse gases. Unprecedented pressures on soil from degradation and urbanization are threatening agro-ecological balances and food security. It is important that we learn more about so...

Characterization of Aral Sea Particulate Matter in Kyrgyzstan

EPA Science Inventory

1. Elemental analyses of resuspendable soils from the Aral Sea region and Kyrgyz soils show that the composition of the soils are remarkably uniform thereby supporting chemical source apportionment models that treat this region as a homogeneous source with respect to elemental co...

Characterization of microbes carried in dust

USDA-ARS?s Scientific Manuscript database

There is still a lack of understanding of how soil microbial community distribution is controlled by wind erosion. This information is of international concern as eroded sediments can potentially carry away the active labile organic soil particulates containing key microorganisms involved in soil bi...

Spatial distribution of metals in soils in Baltimore, Maryland: role of native parent material, proximity to major roads, housing age and screening guidelines

Treesearch

I.D. Yesilonis; R.V. Pouyat; N.K. Neerchal

2008-01-01

We investigated the spatial distribution of heavy metal above-background (anthropic) contents of Cd, Co, Cu, Cr, Fe, Mn, Ni, Pb, Ti, V, and Zn in Baltimore City surface soils and related these levels to potential contaminating sources. Composite soil samples (0?10 cm depth) were digested using a nitric and hydrochloric extraction technique. Slightly more than 10% of...

Risk Assessment Report, Davis Global Communications Site

DTIC Science & Technology

1994-02-23

trivalent chromium . Hexavalent chromium typically is unstable in soil and readily mobilized in both acid and alkaline soils (Bartlett and James, 1979...Environ. Qual. 8: 31. 1 Bartlett, R. J., and J. M. Kimble. 1976a. "Behavior of chromium in soils. I. Trivalent forms." J Environ. QuaL 5: 379-382. 3 i...Background data were not available from these sources for antimony, cadmium, hexavalent chromium , thallium, and silver. Other literature sources, discussed

Joint Multifractal Analysis of penetration resistance variability in an olive orchard.

NASA Astrophysics Data System (ADS)

Lopez-Herrera, Juan; Herrero-Tejedor, Tomas; Saa-Requejo, Antonio; Villeta, Maria; Tarquis, Ana M.

2016-04-01

Spatial variability of soil properties is relevant for identifying those zones with physical degradation. We used descriptive statistics and multifractal analysis for characterizing the spatial patterns of soil penetrometer resistance (PR) distributions and compare them at different soil depths and soil water content to investigate the tillage effect in soil compactation. The study was conducted on an Inceptisol dedicated to olive orchard for the last 70 years. Two parallel transects of 64 m were selected as different soil management plots, conventional tillage (CT) and no tillage (NT). Penetrometer resistance readings were carried out at 50 cm intervals within the first 20 cm of soil depth (López de Herrera et al., 2015a). Two way ANOVA highlighted that tillage system, soil depth and their interaction are statistically significant to explain the variance of PR data. The comparison of CT and NT results at different depths showed that there are significant differences deeper than 10 cm but not in the first two soil layers. The scaling properties of each PR profile was characterized by τ(q) function, calculated in the range of moment orders (q) between -5 and +5 taken at 0.5 lag increments. Several parameters were calculated from this to establish different comparisons (López de Herrera et al., 2015b). While the multifractal analysis characterizes the distribution of a single variable along its spatial support, the joint multifractal analysis can be used to characterize the joint distribution of two or more variables along a common spatial support (Kravchenko et al., 2000; Zeleke and Si, 2004). This type of analysis was performed to study the scaling properties of the joint distribution of PR at different depths. The results showed that this type of analysis added valuable information to describe the spatial arrangement of depth-dependent penetrometer data sets in all the soil layers. References Kravchenko AN, Bullock DG, Boast CW (2000) Joint multifractal analysis of crop yield and terrain slope. Agro. j. 92: 1279-1290. López de Herrera, J., Tomas Herrero Tejedor, Antonio Saa-Requejo and Ana M. Tarquis (2015a) Influence of tillage in soil penetration resistance variability in an olive orchard. Geophysical Research Abstracts, 17, EGU2015-15425. López de Herrera, J., Tomás Herrero Tejedor, Antonio Saa-Requejo, A.M. Tarquis. Influence of tillage in soil penetration resistance variability in an olive orchard. Soil Research, accepted, 2015b. doi: SR15046 Zeleke TB, Si BC (2004) Scaling properties of topographic indices and crop yield: Multifractal and joint multifractal approaches. Agro. j. 96: 1082-1090.

DOE-EPSCOR SPONSORED PROJECT FINAL REPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Jianting

Concern over the quality of environmental management and restoration has motivated the model development for predicting water and solute transport in the vadose zone. Soil hydraulic properties are required inputs to subsurface models of water flow and contaminant transport in the vadose zone. Computer models are now routinely used in research and management to predict the movement of water and solutes into and through the vadose zone of soils. Such models can be used successfully only if reliable estimates of the soil hydraulic parameters are available. The hydraulic parameters considered in this project consist of the saturated hydraulic conductivity andmore » four parameters of the water retention curves. To quantify hydraulic parameters for heterogeneous soils is both difficult and time consuming. The overall objective of this project was to better quantify soil hydraulic parameters which are critical in predicting water flows and contaminant transport in the vadose zone through a comprehensive and quantitative study to predict heterogeneous soil hydraulic properties and the associated uncertainties. Systematic and quantitative consideration of the parametric heterogeneity and uncertainty can properly address and further reduce predictive uncertainty for contamination characterization and environmental restoration at DOE-managed sites. We conducted a comprehensive study to assess soil hydraulic parameter heterogeneity and uncertainty. We have addressed a number of important issues related to the soil hydraulic property characterizations. The main focus centered on new methods to characterize anisotropy of unsaturated hydraulic property typical of layered soil formations, uncertainty updating method, and artificial neural network base pedo-transfer functions to predict hydraulic parameters from easily available data. The work also involved upscaling of hydraulic properties applicable to large scale flow and contaminant transport modeling in the vadose zone and geostatistical characterization of hydraulic parameter heterogeneity. The project also examined the validity of the some simple average schemes for unsaturated hydraulic properties widely used in previous studies. A new suite of pedo-transfer functions were developed to improve the predictability of hydraulic parameters. We also explored the concept of tension-dependent hydraulic conductivity anisotropy of unsaturated layered soils. This project strengthens collaboration between researchers at the Desert Research Institute in the EPSCoR State of Nevada and their colleagues at the Pacific Northwest National Laboratory. The results of numerical simulations of a field injection experiment at Hanford site in this project could be used to provide insights to the DOE mission of appropriate contamination characterization and environmental remediation.« less

[Assessment of soil degradation in regions of nuclear power explosions at Semipalatinsk Nuclear Test Site].

PubMed

Evseeva, T I; Geras'kin, S A; Maĭstrenko, T A; Belykh, E S

2011-01-01

Degree of the soil cover degradation at the "Balapan" and "Experimental field" test sites was assessed based on Allium-test of soil toxicity results and international guidelines on radioactive restriction of solid materials (IAEA, 2004) and environment (Smith, 2005). Soil cover degradation maps of large-scale (1 : 25000) were made. The main part of the area mapped belongs to high-contaminated toxic degraded soil. A relationship between the soil toxicity and the total radionuclide activity concentrations was found to be described by power functions. When the calculated value (equal to 413-415 Bq/kg of air dry soil) increases, the soil becomes toxic for plants. This value is 7.8 times higher than the maximal value for background territories (53 Bq/kg) surrounding SNTS. Russian sanitary and hygienic guidelines (Radiation safety norms, 2009; Sanitary regulations of radioactive waste management, 2003) underestimate the degree of soil radioactive contamination for plants.

[Effects of global change on soil fauna diversity: A review].

PubMed

Wu, Ting-Juan

2013-02-01

Terrestrial ecosystem consists of aboveground and belowground components, whose interaction affects the ecosystem processes and functions. Soil fauna plays an important role in biogeochemical cycles. With the recognizing of the significance of soil fauna in ecosystem processes, increasing evidences demonstrated that global change has profound effects on soil faunima diversity. The alternation of land use type, the increasing temperature, and the changes in precipitation pattern can directly affect soil fauna diversity, while the increase of atmospheric CO2 concentration and nitrogen deposition can indirectly affect the soil fauna diversity by altering plant community composition, diversity, and nutrient contents. The interactions of different environmental factors can co-affect the soil fauna diversity. To understand the effects of different driving factors on soil fauna diversity under the background of climate change would facilitate us better predicting how the soil fauna diversity and related ecological processes changed in the future.

Potential role of soil properties in the spread of CWD in western Canada.

PubMed

Kuznetsova, Alsu; McKenzie, Debbie; Banser, Pamela; Siddique, Tariq; Aiken, Judd M

2014-01-01

Chronic wasting disease (CWD) is a horizontally transmissible prion disease of free ranging deer, elk and moose. Recent experimental transmission studies indicate caribou are also susceptible to the disease. CWD is present in southeast Alberta and southern Saskatchewan. This CWD-endemic region is expanding, threatening Manitoba and areas of northern Alberta and Saskatchewan, home to caribou. Soil can serve as a stable reservoir for infectious prion proteins; prions bound to soil particles remain infectious in the soils for many years. Soils of western Canada are very diverse and the ability of CWD prions to bind different soils and the impact of this interaction on infectivity is not known. In general, clay-rich soils may bind prions avidly and enhance their infectivity comparable to pure clay mineral montmorillonite. Organic components of soils are also diverse and not well characterized, yet can impact prion-soil interaction. Other important contributing factors include soil pH, composition of soil solution and amount of metals (metal oxides). In this review, properties of soils of the CWD-endemic region in western Canada with its surrounding terrestrial environment are described and used to predict bioavailability and, thus, potential spread of CWD. The major soils in the CWD-endemic region of Alberta and Saskatchewan are Chernozems, present in 60% of the total area; they are generally similar in texture, clay mineralogy and soil organic matter content, and can be characterized as clay loamy, montmorillonite (smectite) soils with 6-10% organic carbon. The greatest risk of CWD spread in western Canada relates to clay loamy, montmorillonite soils with humus horizon. Such soils are predominant in the southern region of Alberta, Saskatchewan and Manitoba, but are less common in northern regions of the provinces where quartz-illite sandy soils with low amount of humus prevail.

[Study on the polarized reflectance hyperspectral characteristics and models of typical saline soil in the west of Jilin Province, China].

PubMed

Han, Yang; Qin, Wei-chao; Wang, Ye-qiao

2014-06-01

In recent years, the area of saline soil in the west of Jilin Province expands increasingly, and soil quality is becoming more and more worsening, which not only caused great damage to the land resources, but also posed a huge threat to agricultural production and ecological environment. We combined with polarized and hyperspectral information to establish the general model and scientifically validated it. The results show that there is a strong relationship between the saline soil hyperspectral polarized information and its physicochemical property parameters, and with regularity. This paper has important theoretical significance for the mechanism of saline soil surface reflection, recognition and classification of saline soil and background, the utilization of soil polarization sensor and the development of quantitative remote sensing.

Prediction of iron oxide contents using diffuse reflectance spectroscopy

NASA Astrophysics Data System (ADS)

Marques, José, Jr.; Arantes Camargo, Livia

2015-04-01

Determining soil iron oxides using conventional analysis is relatively unfeasible when large areas are mapped, with the aim of characterizing spatial variability. Diffuse reflectance spectroscopy (DRS) is rapid, less expensive, non-destructive and sometimes more accurate than conventional analysis. Furthermore, this technique allows the simultaneous characterization of many soil attributes with agronomic and environmental relevance. This study aims to assess the DRS capability to predict iron oxides content -hematite and goethite - , characterizing their spatial variability in soils of Brazil. Soil samples collected from an 800-hectare area were scanned in the visible and near-infrared spectral range. Moreover, chemometric calibration was obtained through partial least-squares regression (PLSR). Then, spatial distribution maps of the attributes were constructed using predicted values from calibrated models through geostatistical methods. The studied area presented soils with varied contents of iron oxides as examples for the Oxisols and Entisols. In the spectra of each soil is observed that the reflectance decreases with the content of iron oxides present in the soil. In soils with a high content of iron oxides can be observed more pronounced concavities between 380 and 1100 nm which are characteristic of the presence of these oxides. In soils with higher reflectance it were observed concavity characteristics due to the presence of kaolinite, in agreement with the low iron contents of those soils. The best accuracy of prediction models [residual prediction deviation (RPD) = 1.7] was obtained for goethite within the visible region (380-800 nm), and for hematite (RPD = 2.0) within the visible near infrared (380-2300 nm). The maps of goethite and hematite predicted showed the spatial distribution pattern similar to the maps of clay and iron extracted by dithionite-citrate-bicarbonate, being consistent with the iron oxide contents of soils present in the study area. These results confirm the value of DRS in the mapping of iron oxides in large areas at detailed scale.

Quantifying the main sediment sources in agricultural landscapes of Southern Brazil cultivated with conventional and conservation practices

NASA Astrophysics Data System (ADS)

Evrard, Olivier; Le Gall, Marion; Tiecher, Tales; Gomes Minella, Jean Paolo; Laceby, J. Patrick; Ayrault, Sophie

2017-04-01

Agricultural expansion that occurred in the 1960s in Southern Brazil significantly increased soil erosion and sediment supply to the river networks. To limit the deleterious impacts of soil erosion, conservation practices were progressively implemented in the 1990s, including the direct sowing of crops on a soil densely covered with plant residues, contour farming, the installation of ponds to trap sediment in the landscape and the use of crop rotations. However, there remains a lack of observational data to investigate the impact of these conservation practices on soil erosion and sediment supply. This data is crucial to protect soil resources and maintain the sustainability of food production systems in this region of the world characterized by a rapidly increasing population. Accordingly, sediment sources were investigated in the Guaporé catchment (2,032 km2) representative of the cultivated environments found in this part of the world. In the upper catchment, the landscape is characterized by gentle slopes and deep soils (Ferralsols, Nitisols) corresponding to the edge of the basaltic plateau. Soybean, corn and wheat under direct sowing are the main crops in this area. In contrast, steep and shallow soils (Luvisols, Acrisols, Leptosols) highly connected to the rivers are found in the lower catchment, where tobacco and corn fields are cultivated with conventional ploughing. These soil types were characterized by elemental geochemistry and 87Sr/86Sr ratios. Sediment sources were then modelled using the optimal suite of properties (87Sr/86Sr ratios, K, Ti, Co, As, Ba, and Pb). The results demonstrate that sediment collected at the catchment outlet during two hydrological years (2012-2014) mainly originated from downstream soils (Luvisols, Acrisols, Leptosols; 92±3%), with this proportion remaining stable throughout the monitoring period. This research indicates that conservation practices implemented in the upper catchment are effective and that similar methods should be applied to downstream soils in order to conserve soil resources and limit the degradation of freshwater environments.

13C NMR spectroscopy characterization of particle-size fractionated soil organic carbon in subalpine forest and grassland ecosystems.

PubMed

Shiau, Yo-Jin; Chen, Jenn-Shing; Chung, Tay-Lung; Tian, Guanglong; Chiu, Chih-Yu

2017-12-01

Soil organic carbon (SOC) and carbon (C) functional groups in different particle-size fractions are important indicators of microbial activity and soil decomposition stages under wildfire disturbances. This research investigated a natural Tsuga forest and a nearby fire-induced grassland along a sampling transect in Central Taiwan with the aim to better understand the effect of forest wildfires on the change of SOC in different soil particle scales. Soil samples were separated into six particle sizes and SOC was characterized by solid-state 13 C nuclear magnetic resonance spectroscopy in each fraction. The SOC content was higher in forest than grassland soil in the particle-size fraction samples. The O-alkyl-C content (carbohydrate-derived structures) was higher in the grassland than the forest soils, but the alkyl-C content (recalcitrant substances) was higher in forest than grassland soils, for a higher humification degree (alkyl-C/O-alkyl-C ratio) in forest soils for all the soil particle-size fractions. High humification degree was found in forest soils. The similar aromaticity between forest and grassland soils might be attributed to the fire-induced aromatic-C content in the grassland that offsets the original difference between the forest and grassland. High alkyl-C content and humification degree and low C/N ratios in the fine particle-size fractions implied that undecomposed recalcitrant substances tended to accumulate in the fine fractions of soils.

New characterization aspects of carbonate accumulation horizons in Chalky Champagne (NE of the Paris Basin, France)

NASA Astrophysics Data System (ADS)

Linoir, Damien; Thomachot-Schneider, Céline; Gommeaux, Maxime; Fronteau, Gilles; Barbin, Vincent

2016-05-01

The soil profiles of the Champagne area (NE of Paris Basin, France) occasionally show carbonate accumulation horizons (CAHs). From the top to the bottom, these soil profiles include a rendic leptosol horizon, a Quaternary cryoturbated paleosol (QCP), and a chalky substratum. The CAHs are located in the top part of the QCP. This study is aimed at highlighting the specific characteristics of CAHs compared to other soil profile horizons using geophysics, geochemistry, micromorphology, and mercury injection porosimetry. It is the first essential step for understanding the impact of CAHs on water transfers into the Champagne soil profiles. Our analyses show that Champagne CAHs are not systematically characterized by a typical induration unlike generally put forward in the regional literature. They are more porous and heterogeneous than their parent material (QCP). Carbonate accumulation horizons are also characterized by singular colorimetric parameters that are linked to their geochemical specific content, even if they bear a signature of the initial QCP before the pedogenic modification.

Soil nutrients, bacteria populations, and veterinary pharmaceuticals across a backgrounding beef feedlot

USDA-ARS?s Scientific Manuscript database

Beef cattle backgrounding feedlot systems that grow out weaned calves for feedlot finishing can become potential diffuse sources of environmentally significant contaminants. Better understanding of these contaminants and their distribution will aid in development of effective contaminant management...

Determination of lead and cadmium concentration limits in agricultural soil and municipal solid waste compost through an approach of zero tolerance to food contamination.

PubMed

Saha, Jayanta Kumar; Panwar, N R; Singh, M V

2010-09-01

Cadmium and lead are important environmental pollutants with high toxicity to animals and human. Soils, though have considerable metal immobilizing capability, can contaminate food chain via plants grown upon them when their built-up occurs to a large extent. Present experiment was carried out with the objective of quantifying the limits of Pb and Cd loading in soil for the purpose of preventing food chain contamination beyond background concentration levels. Two separate sets of pot experiment were carried out for these two heavy metals with graded levels of application doses of Pb at 0.4-150 mg/kg and Cd at 0.02-20 mg/kg to an acidic light textured alluvial soil. Spinach crop was grown for 50 days on these treated soils after a stabilization period of 2 months. Upper limit of background concentration levels (C(ul)) of these metals were calculated through statistical approach from the heavy metals concentration values in leaves of spinach crop grown in farmers' fields. Lead and Cd concentration limits in soil were calculated by dividing C(ul) with uptake response slope obtained from the pot experiment. Cumulative loading limits (concentration limits in soil minus contents in uncontaminated soil) for the experimental soil were estimated to be 170 kg Pb/ha and 0.8 kg Cd/ha. Based on certain assumptions on application rate and computed cumulative loading limit values, maximum permissible Pb and Cd concentration values in municipal solid waste (MSW) compost were proposed as 170 mg Pb/kg and 0.8 mg Cd/kg, respectively. In view of these limiting values, about 56% and 47% of the MSW compost samples from different cities are found to contain Pb and Cd in the safe range.

Background concentrations and reference values for heavy metals in soils of Cuba.

PubMed

Alfaro, Mirelys Rodríguez; Montero, Alfredo; Ugarte, Olegario Muñiz; do Nascimento, Clístenes Williams Araújo; de Aguiar Accioly, Adriana Maria; Biondi, Caroline Miranda; da Silva, Ygor Jacques Agra Bezerra

2015-01-01

The potential threat of heavy metals to human health has led to many studies on permissible levels of these elements in soils. The objective of this study was to establish quality reference values (QRVs) for Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, As, Hg, V, Ba, Sb, Ag, Co, and Mo in soils of Cuba. Geochemical associations between trace elements and Fe were also studied, aiming to provide an index for establishing background concentrations of metals in soils. Surface samples of 33 soil profiles from areas of native forest or minimal anthropic influence were collected. Samples were digested (USEPA method 3051A), and the metals were determined by ICP-OES. The natural concentrations of metals in soils of Cuba followed the order Fe > Mn > Ni > Cr > Ba > V > Zn > Cu > Pb > Co > As > Sb > Ag > Cd > Mo > Hg. The QRVs found for Cuban soils were as follows (mg kg(-1)): Ag (1), Ba (111), Cd (0.6), Co (25), Cr (153), Cu (83), Fe (54,055), Mn (1947), Ni (170), Pb (50), Sb (6), V (137), Zn (86), Mo (0.1), As (19), and Hg (0.1). The average natural levels of heavy metals are above the global average, especially for Ni and Cr. The chemical fractionation of soil samples presenting anomalous concentrations of metals showed that Cu, Ni, Cr, Sb, and As have low bioavailability. This suggests that the risk of contamination of agricultural products via plant uptake is low. However, the final decision on the establishment of soil QRVs in Cuba depends on political, economic, and social issues and in-depth risk analyses considering all routes of exposure to these elements.

Spatial heterogeneity of physicochemical properties explains differences in microbial composition in arid soils from Cuatro Cienegas, Mexico.

PubMed

Pajares, Silvia; Escalante, Ana E; Noguez, Ana M; García-Oliva, Felipe; Martínez-Piedragil, Celeste; Cram, Silke S; Eguiarte, Luis Enrique; Souza, Valeria

2016-01-01

Arid ecosystems are characterized by high spatial heterogeneity, and the variation among vegetation patches is a clear example. Soil biotic and abiotic factors associated with these patches have also been well documented as highly heterogeneous in space. Given the low vegetation cover and little precipitation in arid ecosystems, soil microorganisms are the main drivers of nutrient cycling. Nonetheless, little is known about the spatial distribution of microorganisms and the relationship that their diversity holds with nutrients and other physicochemical gradients in arid soils. In this study, we evaluated the spatial variability of soil microbial diversity and chemical parameters (nutrients and ion content) at local scale (meters) occurring in a gypsum-based desert soil, to gain knowledge on what soil abiotic factors control the distribution of microbes in arid ecosystems. We analyzed 32 soil samples within a 64 m(2) plot and: (a) characterized microbial diversity using T-RFLPs of the bacterial 16S rRNA gene, (b) determined soil chemical parameters, and (c) identified relationships between microbial diversity and chemical properties. Overall, we found a strong correlation between microbial composition heterogeneity and spatial variation of cations (Ca(2), K(+)) and anions (HCO[Formula: see text], Cl(-), SO[Formula: see text]) content in this small plot. Our results could be attributable to spatial differences of soil saline content, favoring the patchy emergence of salt and soil microbial communities.

Characterizing the natural radiation levels throughout the main geological units of Sabkhat al Jabboul area, northern Syria.

PubMed

Al-Hilal, Mohamed; Aissa, Mosa

2015-02-01

The concentrations of equivalent eU, eTh, and K% were determined together with soil gas radon values and carborne gamma-ray survey in order to define the natural radioactivity levels throughout main geological units of Sabkhat al Jabboul region. Forty five soil and rock samples were collected from various lithofacies in each geological unit, and analyzed by γ-ray spectrometric technique for determining the concentration values of major radioelements. Such radiometric data could be used to differentiate between various lithologies of the investigated rocks. Although no distinct radioactive anomalies were found in the area, the radiometric profiles showed some minor variations with slightly higher values than the normal level. Despite the low radioactivity and the lack of rocks diversity in the surveyed area, it was possible to classify some certain rock types based on their radiometric response. The relationships between eU, eTh and their ratios were discussed for the Quaternary, Neogene and Paleogene formations, in order to evaluate the degree of uranium distribution and remobilization. The overall results of this radiometric survey were generally low, and lying within the range of the normal background levels in Syrian. Copyright © 2014 Elsevier Ltd. All rights reserved.

Review of State Soil Cleanup Levels for Dioxin (December 2009)

EPA Science Inventory

This final report summarizes a survey of state soil cleanup levels for dioxin and characterizes the science underlying these values. The objective of this project was to summarize existing state cleanup levels for dioxin in soil, together with their scientific bases where availa...

BIOAVAILABILITY OF METALS IN CONTAMINATED SOIL AND DUST

EPA Science Inventory

Due to widespread metal contamination, it is necessary to characterize soils suspected of metal contamination and determine if the metal levels in these soils pose a hazard. Metal toxicity is often not directly related to the total concentration of metals present due to a numb...

Characterization of commercial iron chelates and their behavior in an alkaline and calcareous soil.

PubMed

Cantera, Rodrigo G; Zamarreño, Angel M; García-Mina, José M

2002-12-18

Iron deficiency is a common problem for many plants grown in alkaline and calcareous soils. To correct this problem, iron is supplied to plants as chelates. Several iron chelates are sold under diverse trademarks with different characteristics. This work evaluated 18 commercial products containing the most representative chelated iron sources used in agricultural practice in Spain when the study was done, namely the ferric chelates of EDDHA, EDDHMA, EDDCHA, EDDHSA, EDTA, and DTPA. The chelates were comprehensively characterized and quantitated by several techniques, including several chromatographic methods. Iron and chelate dynamics in soil were also studied in a model alkaline and calcareous soil. Results indicate that, in this model soil, among the different iron compounds studied only FeEDDHA and analogues have the capacity to maintain soluble iron in soil solution over time. These results are in agreement with general experience under field conditions. Furthermore, among the different ortho-ortho isomers of FeEDDHA's, FeEDDHSA and FeEDDCHA showed greater capacity than FeEDDHA and FeEDDHMA to maintain the chelated iron in soil solution over time.

Physical and chemical characterization of actinides in soil from Johnston Atoll

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, S.F.; Bates, J.K.; Buck, E.C.

1997-02-01

Characterization of the actinide content of a sample of contaminated coral soil from Johnston Atoll, the site of three non-nuclear destructs of nuclear warhead-carrying THOR missiles in 1962, revealed that >99% of the total actinide content is associated with discrete bomb fragments. After removal of these fragments, there was an inverse correlation between actinide content and soil particle size in particles from 43 to 0.4 {mu}m diameter. Detailed analyses of this remaining soil revealed no discrete actinide phase in these soil particles, despite measurable actinide content. Observations indicate that exposure to the environment has caused the conversion of relatively insolublemore » actinide oxides to the more soluble actinyl oxides and actinyl carbonate coordinated complexes. This process has led to dissolution of actinides from discrete particles and migration to the surrounding soil surfaces, resulting in a dispersion greater than would be expected by physical transport of discrete particles alone. 26 refs., 4 figs., 1 tab.« less

Data and statistical summaries of background concentrations of metals in soils and streambed sediments in part of Big Soos Creek drainage basin, King County, Washington

USGS Publications Warehouse

Prych, E.A.; Kresch, D.L.; Ebbert, J.C.; Turney, G.L.

1995-01-01

Twenty-nine soil samples from 14 holes at 9 sites in part of the Big Soos Creek drainage basin in southwest King County, Washington, were collected and analyzed to obtain data on the magnitude and variability of background concentrations of metals in soils. Seven streambed-sediment samples and three streamwater samples from three sites also were collected and analyzed. These data are needed by regulating government agencies to determine if soils at sites of suspected contamination have elevated concentrations of metals, and to evaluate the effectiveness of remediation at sites with known contamination. Concentrations of 43 metals were determined by a total method, and concentrations of 17 metals were determined by a total-recoverable method and two different leaching methods. Metals analyzed for by all methods included most of those on the U.S. Environmental Protection agency list of priority pollutants, plus alluminum, iron, and manganese. Ranges of concentrations of metals determined by the total method are within ranges found by others for the conterminous United States. Concentrations of mercury, manganese, phosphorus, lead, selenium, antimony, and zinc as determined by the total method, and of some of these plus other metals as determined by the other methods were larger in shallow soil (less than 12 inches deep) than in deep soil (greater than 12 inches). Concentrations of metals in streambed sediments were more typical of shallow than deep soils.

Changes in the biological activity of heavy metal- and oil-polluted soils in urban recreation territories

NASA Astrophysics Data System (ADS)

Trifonova, T. A.; Zabelina, O. N.

2017-04-01

Urban recreation areas of different sizes were investigated in the city of Vladimir. The degree of their contamination with heavy metals and oil products was revealed. The content of heavy metals exceeded their maximum permissible concentrations by more than 2.5 times. The total content of heavy metals decreased in the sequence: Zn > Pb > Co > Mn > Cr > Ni. The mass fraction of oil products in the studied soils varied within the range of 0.016-0.28 mg/g. The reaction of soils in public gardens and a boulevard was neutral or close to neutral; in some soil samples, it was weakly alkaline. The top layer of all the soils significantly differed from the lower one by the higher alkalinity promoting the deposition of heavy metals there. As the content of Ni, Co, and Mn increased and exceeded the background concentrations, but did not reach the three-fold value of the maximum permissible concentrations, the activity of catalase was intensified. The stimulating effect of nickel on the catalase activity was mostly pronounced at the neutral soil reaction. The urease activity increased when heavy metals and oil products were present together in the concentrations above the background ones, but not higher than the three-fold maximal permissible concentrations for heavy metals and 0.3 mg/g for the content of oil products. The nitrifying activity was inhibited by oil hydrocarbons that were recorded in the soils in different amounts.

Influence of climate and land use change on spatially resolved volatilization of persistent organic pollutants (POPs) from background soils.

PubMed

Komprda, Jiří; Komprdová, Klára; Sáňka, Milan; Možný, Martin; Nizzetto, Luca

2013-07-02

The subject of this study is the assessment of the influence of climate and land use change on the potential re-emission of organochlorine pesticides (OCPs) from background and agricultural soils. A deterministic spatially and temporally explicit model of the air-surface exchange was created, fed with distributed data of soil and atmospheric concentrations from real measurements, and run under various scenarios of temperature and land use change for a case study area representative of central European conditions. To describe land use influence, some important features were implemented including effect of plowing, influence of land cover, temperature of soil, and seasonal changes of air layer stability. Results show that volatilization of pesticides from soil largely exceeded dry gas deposition in most of the area. Agricultural soils accounted for more than 90% of the total re-emissions both because of the generally higher soil fugacities (higher loads of chemicals and relatively low organic carbon content), but also due to physical characteristics and land management practices enhancing the dynamics of the exchange. An increase of 1 °C in air temperature produced an increase of 8% in the averaged total volatilization flux, however this effect can be neutralized by a change of land use of 10% of the arable lands to grassland or forest, which is consistent with projected land use change in Europe. This suggests that future assessment of climate impact on POP fate and distribution should take into consideration land use aspects.

Dielectric Constant Measurements on Lunar Soils and Terrestrial Minerals

NASA Technical Reports Server (NTRS)

Anderson, R. C.; Buehler, M. G.; Seshardri, S.; Schaap, M. G.

2004-01-01

The return to the Moon has ignited the need to characterize the lunar regolith using in situ methods. An examination of the lunar regolith samples collected by the Apollo astronauts indicates that only a few minerals (silicates and oxides) need be considered for in situ resource utilization (ISRU). This simplifies the measurement requirements and allows a detailed analysis using simple methods. Characterizing the physical properties of the rocks and soils is difficult because of many complex parameters such as soil temperature, mineral type, grain size, porosity, and soil conductivity. In this presentation, we will show that the dielectric constant measurement can provide simple detection for oxides such as TiO2, FeO, and water. Their presence is manifest by an unusually large imaginary permittivity.

Soil structural quality assessment for soil protection regulation

NASA Astrophysics Data System (ADS)

Johannes, Alice; Boivin, Pascal

2017-04-01

Soil quality assessment is rapidly developing worldwide, though mostly focused on the monitoring of arable land and soil fertility. Soil protection regulations assess soil quality differently, focusing on priority pollutants and threshold values. The soil physical properties are weakly considered, due to lack of consensus and experimental difficulties faced with characterization. Non-disputable, easy to perform and inexpensive methods should be available for environmental regulation to be applied, which is unfortunately not the case. As a consequence, quantitative soil physical protection regulation is not applied, and inexpensive soil physical quality indicators for arable soil management are not available. Overcoming these limitations was the objective of a research project funded by the Swiss federal office for environment (FOEN). The main results and the perspectives of application are given in this presentation. A first step of the research was to characterize soils in a good structural state (reference soils) under different land use. The structural quality was assessed with field expertise and Visual Evaluation of the Soil Structure (VESS), and the physical properties were assessed with Shrinkage analysis. The relationships between the physical properties and the soil constituents were linear and highly determined. They represent the reference properties of the corresponding soils. In a second step, the properties of physically degraded soils were analysed and compared to the reference properties. This allowed defining the most discriminant parameters departing the different structure qualities and their threshold limits. Equivalent properties corresponding to these parameters but inexpensive and easy to determine were defined and tested. More than 90% of the samples were correctly classed with this method, which meets, therefore, the requirements for practical application in regulation. Moreover, result-oriented agri-environmental schemes for soil quality are now proposed to farmers based on these indicators.

Mercury in the Soil of the Tunka Depression

NASA Astrophysics Data System (ADS)

Lyapina, E. E.; Cherkashina, A. A.

2018-01-01

The work evaluates the general distribution of mercury in the soil cover of the Tunkinskaya depression (the Republic of Buryatia, the national park "Tunkinsky"). For this purpose, its gross contents in natural and agrogenically transformed soils were studied: plow lands, fallow lands, hayfields and pastures. The physico-technical characteristics of soils, the content of organic carbon, group composition of humus are determined. The method of processing the results included the calculation of the ecological and geochemical parameters: the concentration coefficient relative to the background, MAC, Clark concentration relative to the Earth’s crust, the Earth’s soils, the identification of the relationship with the physical and technical characteristics of the soil, and the content of C02, CO2 carbonates, fulvic and humic acids.

Diffuse degassing survey at the Higashi Izu monogenetic volcano field, Japan

NASA Astrophysics Data System (ADS)

Notsu, Kenji; Pérez, Nemesio M.; Fujii, Naoyuki; Hernández, Pedro A.; Mori, Toshiya; Padrón, Eleazar; Melián, Gladys

2016-04-01

The Higashi-Izu monogenetic volcanic group, which consists of more than 60 volcanoes, overlies the polygenetic volcanoes in the eastern part of the Izu peninsula, Japan, which are distributed over the area of 350 km2. Some of the monogenetic volcanoes are located on northwest-southeast alignments, suggesting that they developed along fissures. Recent volcanic activity occurred offshore, e.g., at the Izu-Oshima volcano, which erupted in 1986 and a submarine eruption of the small new Teishi knoll off eastern Izu Peninsula in 1989 (Hasebe et al., 2001). This study was carried out to investigate the possible relationship of diffuse CO2 emission and the recent seismic activity recorded NE of Higashi Izu monogenetic volcanic field, to quantify the rate at which CO2 is diffusely degassed from the studied area including Omuroyama volcano and to identify the structures controlling the degassing process. Measurements were carried out over a three day period from 8-10 July 2013. Diffuse CO2 emission surveys were always carried out following the accumulation chamber method and spatial distribution maps were constructed following the sequential Gaussian simulation (sGs) procedure. Soil gas samples were collected at 30-40 cm depth by withdrawal into 60 cc hypodermic syringes to characterize the chemical and isotopic composition of the soil gas. At Omurayama volcano, soil CO2 efflux values ranged from non-detectable to 97.5 g m-2 d-1, while at the seismic swarm zone ranged from 1.5 to 233.2 g m-2 d-1 and at the fault zone ranged from 5.7 to 101.2 g m-2 d-1. Probability-plot technique of all CO2 efflux data showed two different populations, background with a mean of 8.7 g m-2 d-1 and peak with a mean of 92.7 g m-2 d-1. In order to strength the deep seated contribution to the soil gases at the studied are, carbon isotopic analysis were performed in the CO2 gas. Soil gases (He, CO2 and N2) showed a clear mixing trend between air composition and a rich CO2 end member, suggesting the influence of a deep magmatic reservoir on the soil degassing at the studied area. To estimate the total diffuse CO2 output released from Omurayama, the average of 100 simulations was considered, giving an average of 22 ± 2 t d-1 of diffuse CO2 released by Miharayama. Regarding to the geochemical transects along the Amagi Road and perpendicular to the fault, CO2 efflux values >9xBackground were observed close to the location of the fault. These results show possible linear positive anomalies may be caused by the presence of the active fault which has a higher porosity than surrounding soils, allowing an increased flux of CO2 to reach the surface from depth. References: Hasebe et al., 2001. Bull. Volcanol., 63, 377.

[Microelement contents of litter, soil fauna and soil in Pinus koraiensis and broad-leaved mixed forest].

PubMed

Yin, Xiu-qin; Li, Jin-xia; Dong, Wei-hua

2007-02-01

The analysis on the Mn, Zn and Cu contents of litter, soil fauna and soil in Pinus korazenszis and broad-leaved mixed forest in Liangshui Natural Reserve of Xiaoxing' an Mountains showed that the test microelement contents in the litter, soil fauna and soil all followed the sequence of Mn > Zn > Cu, but varied with these environmental components, being in the sequence of soil > litter > soil fauna for Mn, soil fauna > litter and soil for Zn, and soil fauna > soil > litter for Cu. The change range of test microelement contents in litter was larger in broad-leaved forest than in coniferous forest. Different soil fauna differed in their microelement-enrichment capability, e. g. , earthworm, centipede, diplopod had the highest content of Mn, Zn and Cu, respectively. The contents of test microelements in soil fauna had significant correlations with their environmental background values, litter decomposition rate, food habit of soil fauna, and its absorbing selectivity and enrichment to microelements. The microelements contained in 5-20 cm soil layer were more than those in 0-5 cm soil layer, and their dynamics differed in various soil layers.

Relating soil pore geometry to soil water content dynamics decomposed at multiple frequencies

NASA Astrophysics Data System (ADS)

Qin, Mingming; Gimenez, Daniel; Cooper, Miguel

2016-04-01

Soil structure is a critical factor determining the response of soil water content to meteorological inputs such as precipitation. Wavelet analysis can be used to filter a signal into several wavelet components, each characterizing a given frequency. The purpose of this research was to investigate relationships between the geometry of soil pore systems and the various wavelet components derived from soil water content dynamics. The two study sites investigated were located in the state of São Paulo, Brazil. Each site was comprised of five soil profiles, the first site was situated along a 300-meter transect with about 10% slope in a tropical semi-deciduous forest, while the second one spanned 230-meter over a Brazilian savanna with a slope of about 6%. For each profile, between two to four Water Content Reflectometer CS615 (Campbell Scientific, Inc.) probes were installed according to horizonation at depths varying between 0.1 m and 2.3 m. Bulk soil, three soil cores, and one undisturbed soil block were sampled from selected horizons for determining particle size distributions, water retention curves, and pore geometry, respectively. Pore shape and size were determined from binary images obtained from resin-impregnated blocks and used to characterize pore geometry. Soil water contents were recorded at a 20-minute interval over a 4-month period. The Mexican hat wavelet was used to decompose soil water content measurements into wavelet components. The responses of wavelet components to wetting and drying cycles were characterized by the median height of the peaks in each wavelet component and were correlated with particular pore shapes and sizes. For instance, large elongated and irregular pores, largely responsible for the transmission of water, were significantly correlated with wavelet components at high frequencies (40 minutes to 48 hours) while rounded pores, typically associated to water retention, were only significantly correlated to lower frequency ranges (48 hours and two months). These results will be further discussed in the context of the location of the soil horizons within the toposequence.

Soil Organic Carbon Degradation during Incubation, Barrow, Alaska, 2012

DOE Data Explorer

Elizabeth Herndon; Ziming Yang; Baohua Gu

2017-01-05

This dataset provides information about soil organic carbon decomposition in Barrow soil incubation studies. The soil cores were collected from low-center polygon (Area A) and were incubated in the laboratory at different temperatures for up to 60 days. Transformations of soil organic carbon were characterized by UV and FT-IR, and small organic acids in water-soluble carbons were quantified by ion chromatography during the incubation (Herndon et al., 2015).

Effects of soil oxidation-reduction conditions on internal oxygen transport, root aeration, and growth of wetland plants

Treesearch

S.R. Pezeshki; R.D. DeLaune

2000-01-01

Characterization of hydric soils and the relationship between soil oxidation-reduction processes and wetland plant distribution are critical to the identification and delineation of wetlands and to our understanding of soil processes and plant functioning in wetland ecosystems. However, the information on the relationship between flood response of wetland plants and...

Diversity of Culturable Soil Micro-fungi along Altitudinal Gradients of Eastern Himalayas

PubMed Central

Devi, Lamabam Sophiya; Khaund, Polashree; Nongkhlaw, Fenella M. W.

2012-01-01

Very few studies have addressed the phylogenetic diversity of fungi from Northeast India under the Eastern Himalayan range. In the present study, an attempt has been made to study the phylogenetic diversity of culturable soil fungi along the altitudinal gradients of eastern Himalayas. Soil samples from 24 m above sea level to 2,000 m above sea level altitudes of North-East India were collected to investigate soil micro-fungal community structure and diversity. Molecular characterization of the isolates was done by PCR amplification of 18S rDNA using universal primers. Phylogenetic analysis using BLAST revealed variation in the distribution and richness of different fungal biodiversity over a wide range of altitudes. A total of 107 isolates were characterized belonging to the phyla Ascomycota and Zygomycota, corresponding to seven orders (Eurotiales, Hypocreales, Calosphaeriales, Capnodiales, Pleosporales, Mucorales, and Mortierellales) and Incertae sedis. The characterized isolates were analysed for richness, evenness and diversity indices. Fungal diversity had significant correlation with soil physico-chemical parameters and the altitude. Eurotiales and Hypocreales were most diverse and abundant group of fungi along the entire altitudinal stretch. Species of Penicillium (D = 1.44) and Aspergillus (D = 1.288) were found to have highest diversity index followed by Talaromyces (D = 1.26) and Fusarium (D = 1.26). Fungal distribution showed negative correlation with altitude and soil moisture content. Soil temperature, pH, humidity and ambient temperature showed positive correlation with fungal distribution. PMID:23115506

Distinct soil microbial diversity under long-term organic and conventional farming

PubMed Central

Hartmann, Martin; Frey, Beat; Mayer, Jochen; Mäder, Paul; Widmer, Franco

2015-01-01

Low-input agricultural systems aim at reducing the use of synthetic fertilizers and pesticides in order to improve sustainable production and ecosystem health. Despite the integral role of the soil microbiome in agricultural production, we still have a limited understanding of the complex response of microbial diversity to organic and conventional farming. Here we report on the structural response of the soil microbiome to more than two decades of different agricultural management in a long-term field experiment using a high-throughput pyrosequencing approach of bacterial and fungal ribosomal markers. Organic farming increased richness, decreased evenness, reduced dispersion and shifted the structure of the soil microbiota when compared with conventionally managed soils under exclusively mineral fertilization. This effect was largely attributed to the use and quality of organic fertilizers, as differences became smaller when conventionally managed soils under an integrated fertilization scheme were examined. The impact of the plant protection regime, characterized by moderate and targeted application of pesticides, was of subordinate importance. Systems not receiving manure harboured a dispersed and functionally versatile community characterized by presumably oligotrophic organisms adapted to nutrient-limited environments. Systems receiving organic fertilizer were characterized by specific microbial guilds known to be involved in degradation of complex organic compounds such as manure and compost. The throughput and resolution of the sequencing approach permitted to detect specific structural shifts at the level of individual microbial taxa that harbours a novel potential for managing the soil environment by means of promoting beneficial and suppressing detrimental organisms. PMID:25350160

A soil-landscape framework for understanding spatial and temporal variability in biogeochemical processes in catchments

NASA Astrophysics Data System (ADS)

McGuire, K. J.; Bailey, S. W.; Ross, D. S.

2017-12-01

Heterogeneity in biophysical properties within catchments challenges how we quantify and characterize biogeochemical processes and interpret catchment outputs. Interactions between the spatiotemporal variability of hydrological states and fluxes and soil development can spatially structure catchments, leading to a framework for understanding patterns in biogeochemical processes. In an upland, glaciated landscape at the Hubbard Brook Experimental Forest (HBEF) in New Hampshire, USA, we are embracing the structure and organization of soils to understand the spatial relations between runoff production zones, distinct soil-biogeochemical environments, and solute retention and release. This presentation will use observations from the HBEF to demonstrate that a soil-landscape framework is essential in understanding the spatial and temporal variability of biogeochemical processes in this catchment. Specific examples will include how laterally developed soils reveal the location of active runoff production zones and lead to gradients in primary mineral dissolution and the distribution of weathering products along hillslopes. Soil development patterns also highlight potential carbon and nitrogen cycling hotspots, differentiate acidic conditions, and affect the regulation of surface water quality. Overall, this work demonstrates the importance of understanding the landscape-level structural organization of soils in characterizing the variation and extent of biogeochemical processes that occur in catchments.

Impacts of heterogeneous organic matter on phenanthrene sorption--Different soil and sediment samples

USGS Publications Warehouse

Karapanagioti, Hrissi K.; Childs, Jeffrey; Sabatini, David A.

2001-01-01

Organic petrography has been proposed as a tool for characterizing the heterogeneous organic matter present in soil and sediment samples. A new simplified method is proposed as a quantitative means of interpreting observed sorption behavior for phenanthrene and different soils and sediments based on their organic petrographical characterization. This method is tested under singe solute conditions and at phenanthrene concentration of 1 μg/L. Since the opaque organic matter fraction dominates the sorption process, we propose that by quantifying this fraction one can interpret organic content normalized sorption distribution coefficient (Koc) values for a sample. While this method was developed and tested for various samples within the same aquifer, in the current study the method is validated for soil and sediment samples from different sites that cover a wide range of organic matter origin, age, and organic content. All 10 soil and sediment samples studied had log Koc values for the opaque particles between 5.6 and 6.8. This range of Koc values illustrates the heterogeneity of opaque particles between sites and geological formations and thus the need to characterize the opaque fraction of materials on a site-by-site basis.

The influence of different types of pesticides on elemental profiles of some fruit trees: Apple and plum

NASA Astrophysics Data System (ADS)

Gheboianu, Anca Irina; Setnescu, Tanta; Setnescu, Radu; Culicov, Otilia; Zinicovscaia, Inga

2017-12-01

The aim of this study is to evaluate the elemental content of various samples from apple and plum orchard - located in Dambovita and Arges Counties - (soil, bark and leaves) and to characterize the influence of different types of pesticides commonly used in orchards. For this purpose, the effect of pesticide/ natural fertilizer couples was studied by characterization of treated and untreated soil composition. Heavy metals were also used as tracers for pesticides concentration monitoring, aiming to get information about their overall concentration and eventually, their critical accumulation into some parts of the studied plants (which shall not exceed the limits regulated by Romanian law and UE directives for pesticides use in fruit-grower). Solid samples were analyzed by wavelength dispersion X-ray fluorescence (WDXRF) and instrumental nuclear activation methods (INAA). Moreover, soil properties (pH and electrical conductivity) were determined in order to characterize agricultural soils and to analyze relationships between heavy metal contents and soil properties. Multivariate data analysis was performed to identify a common source for heavy metals. Correlations between the concentrations of heavy metals in the analyzed samples and pesticides used in these areas were found.

Multifractal and Singularity Maps of soil surface moisture distribution derived from 2D image analysis.

NASA Astrophysics Data System (ADS)

Cumbrera, Ramiro; Millán, Humberto; Martín-Sotoca, Juan Jose; Pérez Soto, Luis; Sanchez, Maria Elena; Tarquis, Ana Maria

2016-04-01

Soil moisture distribution usually presents extreme variation at multiple spatial scales. Image analysis could be a useful tool for investigating these spatial patterns of apparent soil moisture at multiple resolutions. The objectives of the present work were (i) to describe the local scaling of apparent soil moisture distribution and (ii) to define apparent soil moisture patterns from vertical planes of Vertisol pit images. Two soil pits (0.70 m long × 0.60 m width × 0.30 m depth) were excavated on a bare Mazic Pellic Vertisol. One was excavated in April/2011 and the other pit was established in May/2011 after 3 days of a moderate rainfall event. Digital photographs were taken from each Vertisol pit using a Kodak™ digital camera. The mean image size was 1600 × 945 pixels with one physical pixel ≈373 μm of the photographed soil pit. For more details see Cumbrera et al. (2012). Geochemical exploration have found with increasingly interests and benefits of using fractal (power-law) models to characterize geochemical distribution, using the concentration-area (C-A) model (Cheng et al., 1994; Cheng, 2012). This method is based on the singularity maps of a measure that at each point define areas with self-similar properties that are shown in power-law relationships in Concentration-Area plots (C-A method). The C-A method together with the singularity map ("Singularity-CA" method) define thresholds that can be applied to segment the map. We have applied it to each soil image. The results show that, in spite of some computational and practical limitations, image analysis of apparent soil moisture patterns could be used to study the dynamical change of soil moisture sampling in agreement with previous results (Millán et al., 2016). REFERENCES Cheng, Q., Agterberg, F. P. and Ballantyne, S. B. (1994). The separation of geochemical anomalies from background by fractal methods. Journal of Geochemical Exploration, 51, 109-130. Cheng, Q. (2012). Singularity theory and methods for mapping geochemical anomalies caused by buried sources and for predicting undiscovered mineral deposits in covered areas. Journal of Geochemical Exploration, 122, 55-70. Cumbrera, R., Ana M. Tarquis, Gabriel Gascó, Humberto Millán (2012) Fractal scaling of apparent soil moisture estimated from vertical planes of Vertisol pit images. Journal of Hydrology (452-453), 205-212. Martin Sotoca; J.J. Antonio Saa-Requejo, Juan Grau and Ana M. Tarquis (2016). Segmentation of singularity maps in the context of soil porosity. Geophysical Research Abstracts, 18, EGU2016-11402. Millán, H., Cumbrera, R. and Ana M. Tarquis (2016) Multifractal and Levy-stable statistics of soil surface moisture distribution derived from 2D image analysis. Applied Mathematical Modelling, 40(3), 2384-2395.

Integrated use of soil physical and water isotope methods for ecohydrological characterization of desertified areas

NASA Astrophysics Data System (ADS)

Külls, Christoph; Nunes, Alice; Köbel-Batista, Melanie; Branquinho, Cristina; Bianconi, Nadja; Costantini, Eduardo

2014-05-01

Measures for monitoring desertification and soil degradation require a thorough understanding of soil physical properties and of the water balance in order to guide restoration efforts (Costantini et al. 2009). It is hypothesized that long term restoration success on degraded land depends on a series of interacting factors such as exposition, soil type, soil hydrology including lateral flow on hill-slope catenae. Recently, new soil water isotope measurement techniques have been developed (Garvelmann et al. 2012) that provide much faster and reliable stable water isotope profiles in soils. This technique yield information on groundwater recharge, soil water balance and on the origin of water available for plants, which in combination with conservative chemical tracers (chloride) can be validated. A multidisciplinary study including ecologists, soil physicists and hydrologists of the COST Action Desert Restoration Hub was carried out on four semi-arid sites in Portugal. A comparative characterization of soil physical parameters, soil water isotope and chloride profiles was performed in order to estimate pedoclimate, soil aridity, soil water balance and groundwater recharge. In combination with soil physical data a comprehensive and cross-validated characterization of pedoclimate and soil aridity was obtained. These indicators were then integrated and related to plant cover. The long-term rainfall of the four sites ranges from 512 to 638 mm, whereas air temperature is from 15.8 to 17.0°C. The De Martonne index of aridity spans from 19.3 to 24.6, pointing to semiarid to moderately arid climatic conditions. The long-term average number of days when the first 0.50 m of soil is dry ranges from 110 to 134, while the mean annual soil temperature at 0.50 m spans from 15.8 and 19.1°C. The studied profiles show different hydrological characteristics, in particular, the estimated hydraulic conductivity ranges from 0.1-1 to 10-100 µm/s. Three out of four profiles show a marked decrease in water permeability at 0.04, 0.20, or 0.40 m depth. Soil isotope profiles indicated that percolation beneath the root zone and groundwater recharge ranges from 21.7 mm/y to 29.7 mm/y. The recharge rate was positively related to mean annual rainfall and soil organic matter, and interestingly, increased with aridity and desertification. The difference between mean annual rainfall and percolation was positively related to plant cover and in inverse proportion to the aridity index. Our results highlight the importance of combining different methods of site characterization by soil physics, soil water isotopes and soil water chemistry (chloride) with vegetation data, providing a more specific analysis of ecohydrological conditions and their relation to ecosystem functioning and recovery potential. The field protocol applied can provide relevant information for guiding restoration strategies. Costantini, E. A. C., Urbano, F., Aramini, G., Barbetti, R., Bellino, F., Bocci, M., & Tascone, F. (2009). Rationale and methods for compiling an atlas of desertification in Italy. Land Degradation & Development, 20(3), 261-276. Garvelmann, J., Külls, C., & Weiler, M. (2012). A porewater-based stable isotope approach for the investigation of subsurface hydrological processes. Hydrology and Earth System Sciences, 16(2), 631-640.

Urban soil exploration through multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar.

PubMed

Van De Vijver, Ellen; Van Meirvenne, Marc; Vandenhaute, Laura; Delefortrie, Samuël; De Smedt, Philippe; Saey, Timothy; Seuntjens, Piet

2015-07-01

In environmental assessments, the characterization of urban soils relies heavily on invasive investigation, which is often insufficient to capture their full spatial heterogeneity. Non-invasive geophysical techniques enable rapid collection of high-resolution data and provide a cost-effective alternative to investigate soil in a spatially comprehensive way. This paper presents the results of combining multi-receiver electromagnetic induction and stepped-frequency ground penetrating radar to characterize a former garage site contaminated with petroleum hydrocarbons. The sensor combination showed the ability to identify and accurately locate building remains and a high-density soil layer, thus demonstrating the high potential to investigate anthropogenic disturbances of physical nature. In addition, a correspondence was found between an area of lower electrical conductivity and elevated concentrations of petroleum hydrocarbons, suggesting the potential to detect specific chemical disturbances. We conclude that the sensor combination provides valuable information for preliminary assessment of urban soils.

Lunar mineral feedstocks from rocks and soils: X-ray digital imaging in resource evaluation

NASA Technical Reports Server (NTRS)

Chambers, John G.; Patchen, Allan; Taylor, Lawrence A.; Higgins, Stefan J.; Mckay, David S.

1994-01-01

The rocks and soils of the Moon provide raw materials essential to the successful establishment of a lunar base. Efficient exploitation of these resources requires accurate characterization of mineral abundances, sizes/shapes, and association of 'ore' and 'gangue' phases, as well as the technology to generate high-yield/high-grade feedstocks. Only recently have x-ray mapping and digital imaging techniques been applied to lunar resource evaluation. The topics covered include inherent differences between lunar basalts and soils and quantitative comparison of rock-derived and soil-derived ilmenite concentrates. It is concluded that x-ray digital-imaging characterization of lunar raw materials provides a quantitative comparison that is unattainable by traditional petrographic techniques. These data are necessary for accurately determining mineral distributions of soil and crushed rock material. Application of these techniques will provide an important link to choosing the best raw material for mineral beneficiation.

[Spatial Distribution and Potential Ecological Risk Assessment of Heavy Metals in Soils and Sediments in Shunde Waterway, Southern China].

PubMed

Cai, Yi-min; Chen, Wei-ping; Peng, Chi; Wang, Tie-yu; Xiao, Rong-bo

2016-05-15

Environmental quality of soils and sediments around water source area can influence the safety of potable water of rivers. In order to study the pollution characteristics, the sources and ecological risks of heavy metals Zn, Cr, Pb, Cu, Ni and Cd in water source area, surface soils around the waterway and sediments in the estuary of main tributaries were collected in Shunde, and ecological risks of heavy metals were assessed by two methods of potential ecological risk assessment. The mean contents of Zn, Cr, Pb, Cu, Ni and Cd in the surface soils were 186.80, 65.88, 54.56, 32.47, 22.65 and 0.86 mg · kg⁻¹ respectively, and they were higher than their soil background values except those of Cu and Ni. The mean concentrations of Zn, Cr, Pb, Cu, Ni and Cd in the sediments were 312.11, 111.41, 97.87, 92.32, 29.89 and 1.72 mg · kg⁻¹ respectively, and they were higher than their soil background values except that of Ni. The results of principal component analysis illustrated that the main source of Cr and Ni in soils was soil parent materials, and Zn, Pb, Cu and Cd in soils mainly came from wastewater discharge of local manufacturing industry. The six heavy metals in sediments mainly originated from industry emissions around the Shunde waterway. The results of potential ecological risk assessment integrating environmental bioavailability of heavy metals showed that Zn, Cu, Pb and Ni had a slight potential ecological risk. Cd had a slight potential ecological risk in surface soils, but a moderate potential ecological risk in surfaces sediments. Because the potential ecological risk assessment integrating environmental bioavailability of heavy metals took the soil properties and heavy metal forms into account, its results of risks were lower than those of Hakanson methods, and it could avoid overestimating the potential risks of heavy metals.

Modeling the plant uptake of organic chemicals, including the soil-air-plant pathway.

PubMed

Collins, Chris D; Finnegan, Eilis

2010-02-01

The soil-air-plant pathway is potentially important in the vegetative accumulation of organic pollutants from contaminated soils. While a number of qualitative frameworks exist for the prediction of plant accumulation of organic chemicals by this pathway, there are few quantitative models that incorporate this pathway. The aim of the present study was to produce a model that included this pathway and could quantify its contribution to the total plant contamination for a range of organic pollutants. A new model was developed from three submodels for the processes controlling plant contamination via this pathway: aerial deposition, soil volatilization, and systemic translocation. Using the combined model, the soil-air-plant pathway was predicted to account for a significant proportion of the total shoot contamination for those compounds with log K(OA) > 9 and log K(AW) < -3. For those pollutants with log K(OA) < 9 and log K(AW) > -3 there was a higher deposition of pollutant via the soil-air-plant pathway than for those chemicals with log K(OA) > 9 and log K(AW) < -3, but this was an insignificant proportion of the total shoot contamination because of the higher mobility of these compounds via the soil-root-shoot pathway. The incorporation of the soil-air-plant pathway into the plant uptake model did not significantly improve the prediction of the contamination of vegetation from polluted soils when compared across a range of studies. This was a result of the high variability between the experimental studies where the bioconcentration factors varied by 2 orders of magnitude at an equivalent log K(OA). One potential reason for this is the background air concentration of the pollutants under study. It was found background air concentrations would dominate those from soil volatilization in many situations unless there was a soil hot spot of contamination, i.e., >100 mg kg(-1).

Isolation, Purification and Characterization of Antimicrobial Agent Antagonistic to Escherichia coli ATCC 10536 Produced by Bacillus pumilus SAFR-032 Isolated from the Soil of Unaizah, Al Qassim Province of Saudi Arabia.

PubMed

S Alanazi, Abdurrahman; Qureshi, Kamal Ahmad; Elhassan, Gamal Osman; I El-Agamy, Elsayed

Escherichia coli is one of the most common pathogenic bacteria, which cause urinary tract infections in infants as well as in adult human beings. Due to the emergence of antibiotic resistance in E. coli, there is a great demand of new antimicrobial agent for the treatment of infections caused by such E. coli. This study aims to isolate, identify and characterize the native soil-bacterial strains predominate in the soil of Unaizah city, which produce antimicrobial agent antagonistic to E. coli ATCC 10536, followed by isolation, purification and characterization of antimicrobial agent. Pour plate, spread plate and 16S rRNA sequence analysis methods were followed for the isolation and identification of soil bacteria. Ammonium sulphate and dialysis (MWCO-8 KD) methods were followed for the isolation and partial purification of antimicrobial agent from the cell free broths. The characterization of antimicrobial agent was carried out by determining the minimum inhibitory concentration and effects of temperature and pH on the antimicrobial stability. Out of the twenty five soil samples, only one soil-bacterial strain was found to produce antimicrobial agent antagonistic to E. coli ATCC 10536. The isolated soil bacterium was identified as Bacillus pumilus SAFR-032. The soil isolate was characterized and results suggest that 30°C temperature and pH 7.0 were the optimum growth parameters and soybean casein digest broth was the best fermentation medium, whereas the highest production of antimicrobial agent was at 35°C temperature, pH 7.0, shaking at 150-220 rpm and at 60th h of incubation. The maximum yield of antimicrobial agent was obtained at 60% of (NH 4) 2SO 4. The results of characterization of antimicrobial agent suggest that the maximum and minimum antimicrobial activities were at pH 3.0 and 8.0, respectively, whereas antimicrobial activity was unaffected by temperature. The antimicrobial agent was highly stable at varying range of temperature 50-120°C. Minimum inhibitory concentration of antimicrobial agent was found to be 64 μg mL -1. In conclusion, this study might be a great endeavor for the healthcare industry in order to treatment of different infections caused by E. coli and that warrants further investigations to fully standardized and establish the antimicrobial profile of effect(s) of this isolate.

High contamination in the areas surrounding abandoned mines and mining activities: An impact assessment of the Dilala, Luilu and Mpingiri Rivers, Democratic Republic of the Congo.

PubMed

Atibu, Emmanuel K; Lacroix, Pierre; Sivalingam, Periyasamy; Ray, Nicolas; Giuliani, Gregory; Mulaji, Crispin K; Otamonga, Jean-Paul; Mpiana, Pius T; Slaveykova, Vera I; Poté, John

2018-01-01

Abandoned mines and mining activities constitute important sources of toxic metals and Rare Earth Elements (REEs) affecting surrounding environmental compartments and biota. This study investigates the contamination degree and distribution of toxic metals and REEs in contrasting sediment, soil and plant samples surrounding rivers in the African copperbelt area characterized by the presence of numerous abandoned mines, artisanal and industrial mining activities. ICP-MS results highlighted the highest concentration of Cu, Co and Pb in sediments reaching values of 146,801, 18,434 and 899 mg kg -1 , respectively. In soil, the values of 175,859, 21,134 and 1164 mg kg -1 were found for Cu, Co and Pb, respectively. These values are much higher than the sediment guidelines for the protection of aquatic life and international soil clean-up standards. Enrichment factor and geoaccumulation index results indicated important contribution of mining activities to the study sites pollution in addition to natural background. Highest metal accumulation in leaves of Phalaris arundinacea L., was observed, reaching values of 34,061, 5050 and 230 mg kg -1 for Cu, Co, and Pb, respectively. The ∑REE concentration reached values of 2306, 733, 2796 mg kg -1 in sediment, soil and plant samples, respectively. The above results were combined with geographical information including satellite imagery, hydrography and mining concessions. Maps were produced to present the results in a comprehensive and compelling visual format. The results will be disseminated through an innovative mapping online platform to simplify access to data and to facilitate dialogue between stakeholders. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic diversity for grain nutrients in wild emmer wheat: potential for wheat improvement

PubMed Central

Chatzav, Merav; Peleg, Zvi; Ozturk, Levent; Yazici, Atilla; Fahima, Tzion; Cakmak, Ismail; Saranga, Yehoshua

2010-01-01

Background and Aims Micronutrient malnutrition, particularly zinc and iron deficiency, afflicts over three billion people worldwide due to low dietary intake. In the current study, wild emmer wheat (Triticum turgidum ssp. dicoccoides), the progenitor of domesticated wheat, was tested for (1) genetic diversity in grain nutrient concentrations, (2) associations among grain nutrients and their relationships with plant productivity, and (3) the association of grain nutrients with the eco-geographical origin of wild emmer accessions. Methods A total of 154 genotypes, including wild emmer accessions from across the Near Eastern Fertile Crescent and diverse wheat cultivars, were characterized in this 2-year field study for grain protein, micronutrient (zinc, iron, copper and manganese) and macronutrient (calcium, magnesium, potassium, phosphorus and sulphur) concentrations. Key Results Wide genetic diversity was found among the wild emmer accessions for all grain nutrients. The concentrations of grain zinc, iron and protein in wild accessions were about two-fold greater than in the domesticated genotypes. Concentrations of these compounds were positively correlated with one another, with no clear association with plant productivity, suggesting that all three nutrients can be improved concurrently with no yield penalty. A subset of 12 populations revealed significant genetic variation between and within populations for all minerals. Association between soil characteristics at the site of collection and grain nutrient concentrations showed negative associations between soil clay content and grain protein and between soil-extractable zinc and grain zinc, the latter suggesting that the greatest potential for grain nutrient minerals lies in populations from micronutrient-deficient soils. Conclusions Wild emmer wheat germplasm offers unique opportunities to exploit favourable alleles for grain nutrient properties that were excluded from the domesticated wheat gene pool. PMID:20202969

Geological Substrates Shape Tree Species and Trait Distributions in African Moist Forests

PubMed Central

Fayolle, Adeline; Engelbrecht, Bettina; Freycon, Vincent; Mortier, Frédéric; Swaine, Michael; Réjou-Méchain, Maxime; Doucet, Jean-Louis; Fauvet, Nicolas; Cornu, Guillaume; Gourlet-Fleury, Sylvie

2012-01-01

Background Understanding the factors that shape the distribution of tropical tree species at large scales is a central issue in ecology, conservation and forest management. The aims of this study were to (i) assess the importance of environmental factors relative to historical factors for tree species distributions in the semi-evergreen forests of the northern Congo basin; and to (ii) identify potential mechanisms explaining distribution patterns through a trait-based approach. Methodology/Principal Findings We analyzed the distribution patterns of 31 common tree species in an area of more than 700,000 km2 spanning the borders of Cameroon, the Central African Republic, and the Republic of Congo using forest inventory data from 56,445 0.5-ha plots. Spatial variation of environmental (climate, topography and geology) and historical factors (human disturbance) were quantified from maps and satellite records. Four key functional traits (leaf phenology, shade tolerance, wood density, and maximum growth rate) were extracted from the literature. The geological substrate was of major importance for the distribution of the focal species, while climate and past human disturbances had a significant but lesser impact. Species distribution patterns were significantly related to functional traits. Species associated with sandy soils typical of sandstone and alluvium were characterized by slow growth rates, shade tolerance, evergreen leaves, and high wood density, traits allowing persistence on resource-poor soils. In contrast, fast-growing pioneer species rarely occurred on sandy soils, except for Lophira alata. Conclusions/Significance The results indicate strong environmental filtering due to differential soil resource availability across geological substrates. Additionally, long-term human disturbances in resource-rich areas may have accentuated the observed patterns of species and trait distributions. Trait differences across geological substrates imply pronounced differences in population and ecosystem processes, and call for different conservation and management strategies. PMID:22905127

Soil Parameters Drive the Structure, Diversity and Metabolic Potentials of the Bacterial Communities Across Temperate Beech Forest Soil Sequences.

PubMed

Jeanbille, M; Buée, M; Bach, C; Cébron, A; Frey-Klett, P; Turpault, M P; Uroz, S

2016-02-01

Soil and climatic conditions as well as land cover and land management have been shown to strongly impact the structure and diversity of the soil bacterial communities. Here, we addressed under a same land cover the potential effect of the edaphic parameters on the soil bacterial communities, excluding potential confounding factors as climate. To do this, we characterized two natural soil sequences occurring in the Montiers experimental site. Spatially distant soil samples were collected below Fagus sylvatica tree stands to assess the effect of soil sequences on the edaphic parameters, as well as the structure and diversity of the bacterial communities. Soil analyses revealed that the two soil sequences were characterized by higher pH and calcium and magnesium contents in the lower plots. Metabolic assays based on Biolog Ecoplates highlighted higher intensity and richness in usable carbon substrates in the lower plots than in the middle and upper plots, although no significant differences occurred in the abundance of bacterial and fungal communities along the soil sequences as assessed using quantitative PCR. Pyrosequencing analysis of 16S ribosomal RNA (rRNA) gene amplicons revealed that Proteobacteria, Acidobacteria and Bacteroidetes were the most abundantly represented phyla. Acidobacteria, Proteobacteria and Chlamydiae were significantly enriched in the most acidic and nutrient-poor soils compared to the Bacteroidetes, which were significantly enriched in the soils presenting the higher pH and nutrient contents. Interestingly, aluminium, nitrogen, calcium, nutrient availability and pH appeared to be the best predictors of the bacterial community structures along the soil sequences.

Ensemble modeling with pedotransfer functions in the hydropedological context

USDA-ARS?s Scientific Manuscript database

Uncertainty of soil water content and/or soil water flux estimates with soil water models has recently become of a particular interest in various applications. This work provides examples of using pedotransfer functions (PTFs) to build ensembles of models to characterize the uncertainty of simulatio...

Indaziflam sorption-desorption in diverse soils

USDA-ARS?s Scientific Manuscript database

Indaziflam is a new preemergence-herbicide active ingredient, classified as a member of the new chemical class “alkylazine”. There is no published information on its fate and behavior in soil. This study is aimed at characterizing the adsorption and desorption of indaziflam in soils with different p...

Error characterization of microwave satellite soil moisture data sets using fourier analysis

USDA-ARS?s Scientific Manuscript database

Soil moisture is a key geophysical variable in hydrological and meteorological processes. Accurate and current observations of soil moisture over meso to global scales used as inputs to hydrological, weather and climate modelling will benefit the predictability and understanding of these processes. ...

Error characterization of microwave satellite soil moisture data sets using fourier analysis

USDA-ARS?s Scientific Manuscript database

Abstract: Soil moisture is a key geophysical variable in hydrological and meteorological processes. Accurate and current observations of soil moisture over mesoscale to global scales as inputs to hydrological, weather and climate modelling will benefit the predictability and understanding of these p...

Characterizing the Soil Ecology of Red Raspberry Produced under Different Production Regimes

USDA-ARS?s Scientific Manuscript database

Soil and rhizosphere ecology play important roles in plant health and development. Using culture-independent microbial community profiling, we investigated the effects of fertilizer (composted dairy solids + mustard seed meal) on fungal communities in soil and endophytic in a raspberry production sy...

Characterization of a Wide Array of Fluorinated Organic Compounds in Contaminated Soils

EPA Science Inventory

Herein we report the results of analyses on the concentrations of perfluorinated compounds (PFCs) and fluorotelomer alcohols (FTOHs) in soils from a site that has been impacted by human activities. Soil samples were collected from several locations that had been impacted and one...

Soils, surficial geology, and geomorphology of the Bear Creek Valley Low-Level Waste Disposal Development and Demonstration Program site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lietzke, D.A.; Lee, S.Y.; Lambert, R.E.

1988-04-01

An intensive soil survey was conducted on the proposed Low-Level Waste Disposal Development and Demonstration Program site (LLWDDD) in Bear Creek Valley. Soils on the site were related to the underlying residuum and to the surficial colluvium and alluvium. Within any particular geologic formation, soils were subdivided based mostly on the degree of weathering, as reflected by saprolite weathering and morphologic features of the soils. Degree of weathering was related both to slope shape and gradient and to the joint-fracture system. Erosion classes were also used to make further subdivisions of any particular soil. Deep pits were dug in eachmore » of the major Conasauga Group formations (Pumpkin Valley, Rogersville, Maryville, and Nolichucky) for soil and saprolite characterization. Because of the widespread presence of alluvium and colluvium, which are potential sources of fill and final cover material, pits and trenches were dug to characterize the properties of these soils and to try to understand the past geomorphic history of the site. The results of the soil survey investigation indicated that the deeply weathered Pumpkin Valley residuum has good potential for the construction of tumuli or other types of belowground or aboveground burial of prepackaged compacted waste. 11 refs., 30 figs., 3 tabs.« less

Characterization of PCC Cement by Addition of Napa Soil from Subdistrict Sarilamak 50 Kota District as Alternative Additional Material for Semen Padang

NASA Astrophysics Data System (ADS)

Mawardi, M.; Deyundha, D.; Zainul, R.; Zalmi P, R.

2018-04-01

The study has been conducted to determine characteristics of the portland composite cement by the addition of napa soil from Sarilamak subdistrict, 50 Kota District as an alternative additional material at PT. Semen Padang. Napa soil is a natural material highly containing silica and alumina minerals so that it can be one of material in producing cement. This study aims to determine the effect of napa soil on the quality of portland composite cement. Napa soil used in the variation compositions 0%, 4%, 8%, 12% and 16%, for control of cement used 8 % of pozzolan and 0 % of napa soil. Determination of cement quality by testing cement characteristics include blaine test, sieving, lost of ignition or LOI, insoluble residue, normal consistency, setting time and compressive strength. Cement was characterized using XRF. Fineness of cement decreases with the addition of napa soil. Lost of Ignition of cement decreased, while the insoluble residue increased with the addition of napa soil. Normal consistency of cement increasing, so does initial setting time and final setting time of cement. While the resultant compressive strength decreases with the addition of napa soil on 28 days, 342, 325, 307, 306, and 300 kg / cm2.

Sampling Soil for Characterization and Site Description

NASA Technical Reports Server (NTRS)

Levine, Elissa

1999-01-01

The sampling scheme for soil characterization within the GLOBE program is uniquely different from the sampling methods of the other protocols. The strategy is based on an understanding of the 5 soil forming factors (parent material, climate, biota, topography, and time) at each study site, and how each of these interact to produce a soil profile with unique characteristics and unique input and control into the atmospheric, biological, and hydrological systems. Soil profile characteristics, as opposed to soil moisture and temperature, vegetative growth, and atmospheric and hydrologic conditions, change very slowly, depending on the parameter being measured, ranging from seasonally to many thousands of years. Thus, soil information, including profile description and lab analysis, is collected only one time for each profile at a site. These data serve two purposes: 1) to supplement existing spatial information about soil profile characteristics across the landscape at local, regional, and global scales, and 2) to provide specific information within a given area about the basic substrate to which elements within the other protocols are linked. Because of the intimate link between soil properties and these other environmental elements, the static soil properties at a given site are needed to accurately interpret and understand the continually changing dynamics of soil moisture and temperature, vegetation growth and phenology, atmospheric conditions, and chemistry and turbidity in surface waters. Both the spatial and specific soil information can be used for modeling purposes to assess and make predictions about global change.

Incorporation of satellite remote sensing pan-sharpened imagery into digital soil prediction and mapping models to characterize soil property variability in small agricultural fields

NASA Astrophysics Data System (ADS)

Xu, Yiming; Smith, Scot E.; Grunwald, Sabine; Abd-Elrahman, Amr; Wani, Suhas P.

2017-01-01

Soil prediction models based on spectral indices from some multispectral images are too coarse to characterize spatial pattern of soil properties in small and heterogeneous agricultural lands. Image pan-sharpening has seldom been utilized in Digital Soil Mapping research before. This research aimed to analyze the effects of pan-sharpened (PAN) remote sensing spectral indices on soil prediction models in smallholder farm settings. This research fused the panchromatic band and multispectral (MS) bands of WorldView-2, GeoEye-1, and Landsat 8 images in a village in Southern India by Brovey, Gram-Schmidt and Intensity-Hue-Saturation methods. Random Forest was utilized to develop soil total nitrogen (TN) and soil exchangeable potassium (Kex) prediction models by incorporating multiple spectral indices from the PAN and MS images. Overall, our results showed that PAN remote sensing spectral indices have similar spectral characteristics with soil TN and Kex as MS remote sensing spectral indices. There is no soil prediction model incorporating the specific type of pan-sharpened spectral indices always had the strongest prediction capability of soil TN and Kex. The incorporation of pan-sharpened remote sensing spectral data not only increased the spatial resolution of the soil prediction maps, but also enhanced the prediction accuracy of soil prediction models. Small farms with limited footprint, fragmented ownership and diverse crop cycle should benefit greatly from the pan-sharpened high spatial resolution imagery for soil property mapping. Our results show that multiple high and medium resolution images can be used to map soil properties suggesting the possibility of an improvement in the maps' update frequency. Additionally, the results should benefit the large agricultural community through the reduction of routine soil sampling cost and improved prediction accuracy.

Universal Spatial Correlation Functions for Describing and Reconstructing Soil Microstructure

PubMed Central

Skvortsova, Elena B.; Mallants, Dirk

2015-01-01

Structural features of porous materials such as soil define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, or gas exchange between biologically active soil root zone and atmosphere) and solute transport. To characterize soil microstructure, conventional soil science uses such metrics as pore size and pore-size distributions and thin section-derived morphological indicators. However, these descriptors provide only limited amount of information about the complex arrangement of soil structure and have limited capability to reconstruct structural features or predict physical properties. We introduce three different spatial correlation functions as a comprehensive tool to characterize soil microstructure: 1) two-point probability functions, 2) linear functions, and 3) two-point cluster functions. This novel approach was tested on thin-sections (2.21×2.21 cm2) representing eight soils with different pore space configurations. The two-point probability and linear correlation functions were subsequently used as a part of simulated annealing optimization procedures to reconstruct soil structure. Comparison of original and reconstructed images was based on morphological characteristics, cluster correlation functions, total number of pores and pore-size distribution. Results showed excellent agreement for soils with isolated pores, but relatively poor correspondence for soils exhibiting dual-porosity features (i.e. superposition of pores and micro-cracks). Insufficient information content in the correlation function sets used for reconstruction may have contributed to the observed discrepancies. Improved reconstructions may be obtained by adding cluster and other correlation functions into reconstruction sets. Correlation functions and the associated stochastic reconstruction algorithms introduced here are universally applicable in soil science, such as for soil classification, pore-scale modelling of soil properties, soil degradation monitoring, and description of spatial dynamics of soil microbial activity. PMID:26010779

Universal spatial correlation functions for describing and reconstructing soil microstructure.

PubMed

Karsanina, Marina V; Gerke, Kirill M; Skvortsova, Elena B; Mallants, Dirk

2015-01-01

Structural features of porous materials such as soil define the majority of its physical properties, including water infiltration and redistribution, multi-phase flow (e.g. simultaneous water/air flow, or gas exchange between biologically active soil root zone and atmosphere) and solute transport. To characterize soil microstructure, conventional soil science uses such metrics as pore size and pore-size distributions and thin section-derived morphological indicators. However, these descriptors provide only limited amount of information about the complex arrangement of soil structure and have limited capability to reconstruct structural features or predict physical properties. We introduce three different spatial correlation functions as a comprehensive tool to characterize soil microstructure: 1) two-point probability functions, 2) linear functions, and 3) two-point cluster functions. This novel approach was tested on thin-sections (2.21×2.21 cm2) representing eight soils with different pore space configurations. The two-point probability and linear correlation functions were subsequently used as a part of simulated annealing optimization procedures to reconstruct soil structure. Comparison of original and reconstructed images was based on morphological characteristics, cluster correlation functions, total number of pores and pore-size distribution. Results showed excellent agreement for soils with isolated pores, but relatively poor correspondence for soils exhibiting dual-porosity features (i.e. superposition of pores and micro-cracks). Insufficient information content in the correlation function sets used for reconstruction may have contributed to the observed discrepancies. Improved reconstructions may be obtained by adding cluster and other correlation functions into reconstruction sets. Correlation functions and the associated stochastic reconstruction algorithms introduced here are universally applicable in soil science, such as for soil classification, pore-scale modelling of soil properties, soil degradation monitoring, and description of spatial dynamics of soil microbial activity.

Continuous versus pulse neutron induced gamma spectroscopy for soil carbon analysis

USDA-ARS?s Scientific Manuscript database

Neutron induced gamma spectra analysis (NGA) provides a means of measuring carbon in large soil volumes without destructive sampling. Calibration of the NGA system must account for system background and the interference of other nuclei on the carbon peak at 4.43 MeV. Accounting for these factors pro...

Fire-severity effects on plant-fungal interactions after a novel tundra wildfire disturbance: implications for arctic shrub and tree migration

Treesearch

Rebecca E. Hewitt; Teresa N. Hollingsworth; F. Stuart Chapin III; D. Lee Taylor

2016-01-01

Background: Vegetation change in high latitude tundra ecosystems is expected to accelerate due to increased wildfire activity. High-severity fires increase the availability of mineral soil seedbeds, which facilitates recruitment, yet fire also alters soil microbial composition, which could significantly impact seedling establishment.

Impact of reclamation treatment on the biological activity of soils of the solonetz complex in Western Siberia

NASA Astrophysics Data System (ADS)

Berezin, L. V.; Khamova, O. F.; Paderina, E. V.; Gindemit, A. M.

2014-11-01

The abundance and activity of the soil microflora were studied in a field experiment with the use of green manure crops to assess the impact of reclamation measures on the biological activity of soils of the solonetz complex. The number of microorganisms in the plow soil horizon increased in the background of the green fallows as compared to the black ones. Coefficients of mineralization, immobilization, and transformation of organic compounds were calculated for different variants of the soil treatment. The value of the mineralization coefficient indicates the intense decomposition of the green manure that entered the soil. In the first year, peas were actively decomposed, while oats, in the second year (aftereffect). The activity of the soil enzymes (invertase, urease, and catalase) was determined. A close relationship between the catalase activity and the intensity of the microbiological processes in the soils was revealed.

Soil Communities of Central Park, New York City: A Biodiversity Melting Pot

NASA Astrophysics Data System (ADS)

Ramirez, K. S.; Leff, J. W.; Wall, D. H.; Fierer, N.

2013-12-01

The majority of earth's biodiversity lives in and makes up the soil, but the majority of soil biodiversity has yet to be characterized or even quantified. This may be especially true of urban soil systems. The last decade of advances in molecular, technical and bioinformatic techniques have contributed greatly to our understanding of belowground biodiversity, from global distribution to species counts. Yet, much of this work has been done in ';natural' systems and it is not known if established patterns of distribution, especially in relation to soil factors hold up in urban soils. Urban soils are intensively managed and disturbed, often by effects unique to urban settings. It remains unclear how urban pressures influence soil biodiversity, or if there is a defined or typical ';urban soil community'. Here we describe a study to examine the total soil biodiversity - Bacteria, Archaea and Eukarya- of Central Park, New York City and test for patterns of distribution and relationships to soil characteristics. We then compare the biodiversity of Central Park to 57 global soils, spanning a number of biomes from Alaska to Antarctica. In this way we can identify similarities and differences in soil communities of Central Park to soils from ';natural' systems. To generate a broad-scale survey of total soil biodiversity, 596 soil samples were collected from across Central Park (3.41 km2). Soils varied greatly in vegetation cover and soil characteristics (pH, moisture, soil C and soil N). Using high-throughput Illumina sequencing technology we characterized the complete soil community from 16S rRNA (Bacteria and Archaea) and 18S rRNA gene sequences (Eukarya). Samples were rarified to 40,000 sequences per sample. To compare Central Park to the 57 global soils the complete soil community of the global soils was also characterized using Illumina sequencing technology. All samples were rarified to 40,000 sequences per sample. The total measured biodiversity in Central Park was high: >540,000 bacterial and archaeal species; and >97,000 eukaryotic species (as determined using a 97% sequence similarity cutoff). The most dominant bacterial phyla include Proteobacteria, Acidobacteria, Bacteroidetes, Verrucomicrobia and Actinobacteria, and Archaea represent 1-8% of the sequences. Additionally, the distribution patterns of Acidobacteria and consequently beta-diversity, was strongly related to soil pH. The most dominant eukaryotic taxa include many Protists (Rhizara, Gregarinia), Fungi (Basidiomycota, Ascomycota), and Metazoa (Nematodes, Rotifers, Arthropods and Annelids). No single soil factor could predict eukaryotic distribution. Central Park soil diversity was strikingly similar to the diversity of the 57 global soils. Central Park and the global soils had similarities in alpha diversity, taxon abundances. Interestingly, there was significant overlap in a number of dominant species between Central Park and the global soils. Together these results represent the most comprehensive analysis of soil biodiversity conducted to date. Our data suggest that even well-studied locations like Central Park harbor very high levels of unexplored biodiversity, and that Central Park biodiversity is comparable to soil biodiversity found globally.

Reference levels of background radioactivity for beach sands and soils in İnebolu/Kastamonu-Turkey

NASA Astrophysics Data System (ADS)

Kurnaz, Aslı; Türkdoǧan, Savaş; Hançerlioǧulları, Aybaba; ćetiner, M. Atıf

2016-03-01

This paper presents the measurement results of environmental radioactivity levels for İnebolu district (tourist area), Kastamonu-Turkey. The radioactivity concentrations of 238U, 232Th, 40K and the fission product 137Cs in soil samples collected from 13 region surroundings of study area and in 12 beach sand samples collected from along the coast of İnebolu were determined. To evaluate the radiological hazard of the natural radioactivity, based on the measured concentrations of these radionuclides, the mean absorbed gamma dose and the annual effective dose were evaluated separately, and found to be 112.90 nGy h-1 and 138.46 µSv y-1 for soil samples and 75.19 nGy h-1 and 92.22 µSv y-1 for beach sand samples, respectively. The results show that İnebolu does not have high background.

Probability Models Based on Soil Properties for Predicting Presence-Absence of Pythium in Soybean Roots.

PubMed

Zitnick-Anderson, Kimberly K; Norland, Jack E; Del Río Mendoza, Luis E; Fortuna, Ann-Marie; Nelson, Berlin D

2017-10-01

Associations between soil properties and Pythium groups on soybean roots were investigated in 83 commercial soybean fields in North Dakota. A data set containing 2877 isolates of Pythium which included 26 known spp. and 1 unknown spp. and 13 soil properties from each field were analyzed. A Pearson correlation analysis was performed with all soil properties to observe any significant correlation between properties. Hierarchical clustering, indicator spp., and multi-response permutation procedures were used to identify groups of Pythium. Logistic regression analysis using stepwise selection was employed to calculate probability models for presence of groups based on soil properties. Three major Pythium groups were identified and three soil properties were associated with these groups. Group 1, characterized by P. ultimum, was associated with zinc levels; as zinc increased, the probability of group 1 being present increased (α = 0.05). Pythium group 2, characterized by Pythium kashmirense and an unknown Pythium sp., was associated with cation exchange capacity (CEC) (α < 0.05); as CEC increased, these spp. increased. Group 3, characterized by Pythium heterothallicum and Pythium irregulare, were associated with CEC and calcium carbonate exchange (CCE); as CCE increased and CEC decreased, these spp. increased (α = 0.05). The regression models may have value in predicting pathogenic Pythium spp. in soybean fields in North Dakota and adjacent states.

DNA-based detection of the fungal pathogen Geomyces destructans in soil from bat hibernacula

USGS Publications Warehouse

Lindner, Daniel L.; Gargas, Andrea; Lorch, Jeffrey M.; Banik, Mark T.; Glaeser, Jessie; Kunz, Thomas H.; Blehert, David S.

2011-01-01

White-nose syndrome (WNS) is an emerging disease causing unprecedented morbidity and mortality among bats in eastern North America. The disease is characterized by cutaneous infection of hibernating bats by the psychrophilic fungus Geomyces destructans. Detection of G. destructans in environments occupied by bats will be critical for WNS surveillance, management and characterization of the fungal lifecycle. We initiated an rRNA gene region-based molecular survey to characterize the distribution of G. destructans in soil samples collected from bat hibernacula in the eastern United States with an existing PCR test. Although this test did not specifically detect G. destructans in soil samples based on a presence/absence metric, it did favor amplification of DNA from putative Geomyces species. Cloning and sequencing of PCR products amplified from 24 soil samples revealed 74 unique sequence variants representing 12 clades. Clones with exact sequence matches to G. destructans were identified in three of 19 soil samples from hibernacula in states where WNS is known to occur. Geomyces destructans was not identified in an additional five samples collected outside the region where WNS has been documented. This study highlights the diversity of putative Geomyces spp. in soil from bat hibernacula and indicates that further research is needed to better define the taxonomy of this genus and to develop enhanced diagnostic tests for rapid and specific detection of G. destructans in environmental samples.

Estimates of Soil Ingestion in a Population of Chinese Children

PubMed Central

Wang, Beibei; Cui, Xiaoyong; Xu, Dongqun; Cheng, Hongguang; Wang, Qin; Ma, Jin; Chai, Tuanyao; Duan, Xiaoli; Liu, Xitao; Ma, Junwei; Zhang, Xuan; Liu, Yanzhong

2017-01-01

Background: China’s soil pollution poses serious health risks. However, data regarding the soil ingestion rate (SIR) of the Chinese population, which is critical to assessing associated health risks, are lacking. Objectives: We estimated soil ingestion of 177 Chinese children from Guangdong, Hubei, and Gansu Provinces. Methods: We conducted this investigation by employing a tracer mass-balance method. We collected a duplicate of all food consumed and all feces and urine excreted on 1 d (n=153) and over 3 consecutive d (n=24), as well as soil samples from play areas and drinking-water samples. We analyzed concentrations of the tracer elements Al, Ba, Ce, Mn, Sc, Ti, V, and Y in these samples using ICP-AES and ICP-MS and estimated the SIR for each subject. Results: The estimated SIR data based on each tracer element were characterized by a skewed distribution, as well as higher inter-tracer and inter-subject variation, with several outliers. After removing the outliers, daily SIR median (range) values in milligrams per day were Al, 27.8 (−42.0 to 257.3); Ba, 36.5 (−230.3 to 412.7); Ce, 35.3 (−21.2 to 225.8); Mn, 146.6 (−1259.4 to 1827.7); Sc, 54.8 (−4.5 to 292.0); Ti, 36.7 (−233.7 to 687.0); V, 92.1 (10.4 to 308.0); and Y, 59.1 (−18.4 to 283.0). Daily SIR median/95th percentile (range) values based on the best tracer method (BTM) were 51.7/216.6 (−9.5 to 297.6) mg/d. Conclusions: Based on the BTM, recommended SIR values for the general population of Chinese children (2.5 to 12 years old) are 52mg/d for the central tendency and 217mg/d for the upper percentile. We did not differentiate between outside soil and indoor dust. Considering the lower concentration of tracer elements in indoor dust than outside soil, actual soil and dust ingestion rates could be higher. https://doi.org/10.1289/EHP930 PMID:28728141

STIR Proposal For Research Area 2.1.2 Surface Energy Balance: Transient Soil Density Impacts Land Surface Characteristics and Characterization

DTIC Science & Technology

2015-12-22

not shown). The relatively small differences were likely associated with differences in surface albedo and longwave radiation from soil surface. Ground...SECURITY CLASSIFICATION OF: Soil density is commonly treated as static in studies on land surface property dynamics. Magnitudes of errors associated...with this assumption are largely unknown. Objectives of this preliminary investigation were to: i) quantify effects of soil density variation on soil

Characterization of Anaerobic Chemical Processes in Reservoirs: Problem Description and Conceptual Model Formulation.

DTIC Science & Technology

1981-04-01

also found that almost all the Fe in soil solution was complexed with organic mat- ter. The high degree of Fe complexing in soil solution was...range of pH, the potentials were in conformity with the theoretical slope of 0.06. 45. When a soil is submerged, soil solution concentrations of...Ponnanperuma 1972). Low temperatures lead to extensive accumula- tion of organic acids in the soil solution (International Rice Research Institute (IRRI) 1969

Mineralogy and geochemistry of soils from glass houses and solariums

NASA Astrophysics Data System (ADS)

Bulgariu, Dumitru; Filipov, Feodor; Rusu, Constantin; Bulgariu, Laura

2010-05-01

The experimental studies have been performed on soil samples from Copou-Iaşi, Bacău and Bârlad (România) glass houses. We have specially follow the aspects concerning to the distribution of occurrence forms, composition and structure of mineral and organic components, and the genetic correlations between these in conditions of soils from glass houses, respectively. The results regarding the distribution tendencies on profile and the correlations between mineral and organic components of studied soils have been correlated with the results of microscopic, spectral (IR and Raman) and X-ray diffraction studies, and with the results of thermodynamic modelling of mineral equilibriums and dynamics of pedogenesis processes, in conditions of soils from glass houses. The utilization of intensive cultivation technologies of vegetables in glass houses determined the degradation of morphological, physical and chemical characteristics of soils, by fast evolution of salted processes (salinization and / or sodization), compaction, carbonatation, eluviation-illuviation, frangipane formation, stagnogleization, gleization, etc. Under these conditions, at depth of 30-40 cm is formed a compact and impenetrable horizon with frangipane characteristics, expresses more or less. The aspects about the formation of frangipane horizon in soils from glasshouses are not yet sufficiently know. Whatever of the formation processes, the frangipane horizons determined a sever segregation in pedo-geochemical evolution of soils from glasshouses, with very important consequences on the agrochemical quality of these soils. The soils from glass houses are characterized by a very large variability of mineralogy and chemistry, which are traduced by intense modifications of superior horizons, in many cases there are conditions for the apparition of new pedogenetic horizons through new-pedogenesis processes. Under these conditions the definition of some general characteristics of soils from glasshouses is very difficult. Practically, each type of soil from this category has distinct pedological and chemical-mineralogical characteristics, mostly determined by the nature of parental material and by the exploitation technologies. Concerning to the pedogeochemistry of soils from glasshouses have not yet been written summary studies, most existing papers from literature are in fact, case studies of particular situations. The deficit of information from this field, together with the ambiguity of pedogenetical characters of diagnostic, makes difficult the unitary characterization of soils from glasshouses. Characteristic for the soils from glass houses are the intense modifications of soil profile, the large variability of mineralogy and chemistry, and the salinization processes of superior horizons. From chemical point of view, the soils from glass houses is characterized by high values of bases saturation, accessible phosphorus and ration between humic and fulvic acids. From mineralogical point of view, the soils from glass houses studied is characterized by a high heterogeneity degree, both as contents, and as occurrence and distribution forms of mineral and organic components in profile. Predominant quantitatively are clay minerals and as variety, the crystalline forms are most abundant. As regard the clay minerals type, the kaolin and illites have dominant weights in comparison with smectites and the other mineral components. Acknowledgments The authors would like to acknowledge the financial support from Romanian Ministry of Education and Research (Project PNCDI 2-D5 no. 51045/07).

Cropland Field Monitoring: MMV Page 1 Montana Cropland Enrolled Farm Fields Carbon Sequestration Field Sampling, Measurement, Monitoring, and Verification: Application of Visible-Near Infrared Diffuse Reflectance Spectroscopy (VNIR) and Laser-induced Breakdown Spectroscopy (LIBS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee Spangler; Ross Bricklemyer; David Brown

2012-03-15

There is growing need for rapid, accurate, and inexpensive methods to measure, and verify soil organic carbon (SOC) change for national greenhouse gas accounting and the development of a soil carbon trading market. Laboratory based soil characterization typically requires significant soil processing, which is time and resource intensive. This severely limits application for large-region soil characterization. Thus, development of rapid and accurate methods for characterizing soils are needed to map soil properties for precision agriculture applications, improve regional and global soil carbon (C) stock and flux estimates and efficiently map sub-surface metal contamination, among others. The greatest gains for efficientmore » soil characterization will come from collecting soil data in situ, thus minimizing soil sample transportation, processing, and lab-based measurement costs. Visible and near-infrared diffuse reflectance spectroscopy (VisNIR) and laser-induced breakdown spectroscopy (LIBS) are two complementary, yet fundamentally different spectroscopic techniques that have the potential to meet this need. These sensors have the potential to be mounted on a soil penetrometer and deployed for rapid soil profile characterization at field and landscape scales. Details of sensor interaction, efficient data management, and appropriate statistical analysis techniques for model calibrations are first needed. In situ or on-the-go VisNIR spectroscopy has been proposed as a rapid and inexpensive tool for intensively mapping soil texture and organic carbon (SOC). While lab-based VisNIR has been established as a viable technique for estimating various soil properties, few experiments have compared the predictive accuracy of on-the-go and lab-based VisNIR. Eight north central Montana wheat fields were intensively interrogated using on-the-go and lab-based VisNIR. Lab-based spectral data consistently provided more accurate predictions than on-the-go data. However, neither in situ nor lab-based spectroscopy yielded even semi-quantitative SOC predictions. There was little SOC variability to explain across the eight fields, and on-the-go VisNIR was not able to capture the subtle SOC variability in these Montana soils. With more variation in soil clay content compared to SOC, both lab and on-the-go VisNIR showed better explanatory power. There are several potential explanations for poor on-the-go predictive accuracy: soil heterogeneity, field moisture, consistent sample presentation, and a difference between the spatial support of on-the-go measurements and soil samples collected for laboratory analyses. Though the current configuration of a commercially available on-the-go VisNIR system allows for rapid field scanning, on-the-go soil processing (i.e. drying, crushing, and sieving) could improve soil carbon predictions. Laser-induced breakdown spectroscopy (LIBS) is an emerging elemental analysis technology with the potential to provide rapid, accurate and precise analysis of soil constituents, such as carbon, in situ across landscapes. The research team evaluated the accuracy of LIBS for measuring soil profile carbon in field-moist, intact soil cores simulating conditions that might be encountered by a probe-mounted LIBS instrument measuring soil profile carbon in situ. Over the course of three experiments, more than120 intact soil cores from eight north central Montana wheat fields and the Washington State University (WSU) Cook Agronomy Farm near Pullman, WA were interrogated with LIBS for rapid total carbon (TC), inorganic carbon (IC), and SOC determination. Partial least squares regression models were derived and independently validated at field- and regional scales. Researchers obtained the best LIBS validation predictions for IC followed by TC and SOC. Laser-induced breakdown spectroscopy is fundamentally an elemental analysis technique, yet LIBS PLS2 models appeared to discriminate IC from TC. Regression coefficients from initial models suggested a reliance upon stoichiometric relationships between carbon (247.8 nm) and other elements related to total and inorganic carbon in the soil matrix [Ca (210.2 nm, 211.3 nm, and 220.9 nm), Mg (279.55-280.4 nm, 285.26 nm), and Si (251.6 nm, 288.1 nm)]. Expanding the LIBS spectral range to capture emissions from a broader range of elements related to soil organic matter was explored using two spectrometer systems to improve SOC predictions. Results for increasing the spectral range of LIBS to the full 200-800 nm found modest gains in prediction accuracy for IC, but no gains for predicting TC or SOC. Poor SOC predictions are likely a function of (1) the lack of a consistent/definable molecular composition of SOC, (2) relatively little variation in SOC across field sites, and (3) inorganic carbon constituting the primary form of soil carbon, particularly for Montana soils.« less

Decline in Topsoil Microbial Quotient, Fungal Abundance and C Utilization Efficiency of Rice Paddies under Heavy Metal Pollution across South China

PubMed Central

Liu, Yongzhuo; Zhou, Tong; Crowley, David; Li, Lianqing; Liu, Dawen; Zheng, Jinwei; Yu, Xinyan; Pan, Genxing; Hussain, Qaiser; Zhang, Xuhui; Zheng, Jufeng

2012-01-01

Agricultural soils have been increasingly subject to heavy metal pollution worldwide. However, the impacts on soil microbial community structure and activity of field soils have been not yet well characterized. Topsoil samples were collected from heavy metal polluted (PS) and their background (BGS) fields of rice paddies in four sites across South China in 2009. Changes with metal pollution relative to the BGS in the size and community structure of soil microorganisms were examined with multiple microbiological assays of biomass carbon (MBC) and nitrogen (MBN) measurement, plate counting of culturable colonies and phospholipids fatty acids (PLFAs) analysis along with denaturing gradient gel electrophoresis (DGGE) profile of 16S rRNA and 18S rRNA gene and real-time PCR assay. In addition, a 7-day lab incubation under constantly 25°C was conducted to further track the changes in metabolic activity. While the decrease under metal pollution in MBC and MBN, as well as in culturable population size, total PLFA contents and DGGE band numbers of bacteria were not significantly and consistently seen, a significant reduction was indeed observed under metal pollution in microbial quotient, in culturable fungal population size and in ratio of fungal to bacterial PLFAs consistently across the sites by an extent ranging from 6% to 74%. Moreover, a consistently significant increase in metabolic quotient was observed by up to 68% under pollution across the sites. These observations supported a shift of microbial community with decline in its abundance, decrease in fungal proportion and thus in C utilization efficiency under pollution in the soils. In addition, ratios of microbial quotient, of fungal to bacterial and qCO2 are proved better indicative of heavy metal impacts on microbial community structure and activity. The potential effects of these changes on C cycling and CO2 production in the polluted rice paddies deserve further field studies. PMID:22701725

A protocol for conducting rainfall simulation to study soil runoff

USDA-ARS?s Scientific Manuscript database

Rainfall is a driving force for the transport of environmental contaminants from agricultural soils to surficial water bodies via surface runoff. The objective of this study was to characterize the effects of antecedent soil moisture content on the fate and transport of surface applied commercial ur...

Potential Transport and Degradation of “Aged” Pesticide Residues in Soil

USDA-ARS?s Scientific Manuscript database

Increased pesticide residence time in soil, or “aging”, has been shown to affect the sorption-desorption of pesticides in the soil, which in turn can control transport and degradation processes. Aging effects have been characterized by batch sequential extraction methods, in which sorption coefficie...

Application of a Transient Storage Zone Model o Soil Pipeflow Tracer Injection Experiments

USDA-ARS?s Scientific Manuscript database

Soil pipes, defined here as discrete preferential flow paths generally parallel to the slope, are important subsurface flow pathways that play a role in many soil erosion phenomena. However, limited research has been performed on quantifying and characterizing their flow and transport characteristic...

Soil pipe flow tracer experiments: 2. Application of a transient storage zone model

USDA-ARS?s Scientific Manuscript database

Soil pipes, defined here as discrete preferential flow paths generally parallel to the slope, are important subsurface flow pathways that play a role in many soil erosion phenomena. However, limited research has been performed on quantifying and characterizing their flow and transport characteristic...

BOREAS TF-1 SSA-OA Soil Characteristics Data

NASA Technical Reports Server (NTRS)

Black, T. Andrew; Chen, Z; Nesic, Z.; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

2000-01-01

The BOREAS TF-1 team collected several data sets in support of its efforts to characterize and interpret soil information at the SSA-OA tower site in 1994 as part of BOREAS. Data sets collected include soil respiration, temperature, moisture, and gravimetric data. The data are stored in tabular ASCII format.

Degradation of the Herbicide Metolachlor in Drummer Soil Under Different Redox Conditions

USDA-ARS?s Scientific Manuscript database

Understanding the role of microorganisms and effect of soil environmental conditions on herbicide fate is critical for stewardship of herbicide use in cropping systems. As compared to the modernized perceptions of soil redox status, diminutive progress has been made in characterizing the impact of a...

TRANSPORT AND TRANSFORMATION OF HEXAVALENT CHROMIUM THROUGH SOILS AND INTO GROUND WATER

EPA Science Inventory

A detailed characterization of the underlying and adjacent soils of a chrome-plating shop was performed to provide information on the extent of soil and aquifer contamination at the site and on the potential for off-site migration and environmental impact. Intact, moist cores wer...

Multi-scale soil salinity mapping and monitoring with proximal and remote sensing

USDA-ARS?s Scientific Manuscript database

This talk is part of a technical short course on “Soil mapping and process modelling at diverse scales”. In the talk, guidelines, special considerations, protocols, and strengths and limitations are presented for characterizing spatial and temporal variation in soil salinity at several spatial scale...

Dig In! Hands-On Soil Investigations.

ERIC Educational Resources Information Center

National Science Teachers Association, Arlington, VA.

This guide is geared toward K-4 science teachers, supervisors, and environmental educators. The guide seeks to promote a better understanding and appreciation of soil. Students explore the land around them as they investigate the origins of soil and how it benefits our ecosystems and environment and discover the various habitats characterized by…

TCE TRANSPORT AND DEGRADATION IN SOIL USING ELECTROOSMOSIS

EPA Science Inventory

Laboratory experiments were used to characterize the transport and chemical transformation of TCE in undisturbed soil cores. Electroosmotic fluid flow was vertically downwards from anode to cathode. A voltage of 1.4 V/cm was applied to the soil for 4 weeks. More than 95% of the T...

76 FR 43319 - Record of Decision for the Continued Operation of the Y-12 National Security Complex

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-20

...; visual resources; site infrastructure; traffic and transportation; geology and soils; air quality and... excavation, soil characterization, transportation or disposal associated with the UPF. Response. The Y-12 Final SWEIS includes an analysis of the impacts of the UPF construction, including soil disturbance...

Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...

Mid-Infrared Spectroscopic Properties of Humic Acid and Fulvic Acid-Soil Mixtures.

USDA-ARS?s Scientific Manuscript database

The detection of humic materials in soils is essential in order to determine organic matter (SOM) stability and C sequestration on agricultural land. Mid-Infrared (MidIR) spectroscopy has been used to characterize SOM quality [1], study extracted soil humic acids [2], develop calibrations for quanti...

COSMOS soil water sensing affected by crop biomass and water status

USDA-ARS?s Scientific Manuscript database

Soil water sensing methods are widely used to characterize water content in the root zone and below, but only a few are capable of sensing soil volumes larger than a few hundred liters. Scientists with the USDA-ARS Conservation & Production Research Laboratory, Bushland, Texas, evaluated: a) the Cos...

Vegetation effects on soil organic matter chemistry of aggregate fractions in a Hawaiian forest

USDA-ARS?s Scientific Manuscript database

We examined chemical changes from live plant tissue to soil organic matter (SOM) to determine the persistence of individual plant compounds into soil aggregate fractions. We characterized the tissue chemistry of a slow- (Dicranopteris linearis) and fast-decomposing species (Cheirodendron trigynum) a...

Particle size and X-ray analysis of Feldspar, Calvert, Ball, and Jordan soils

NASA Technical Reports Server (NTRS)

Chapman, R. S.

1977-01-01

Pipette analysis and X-ray diffraction techniques were employed to characterize the particle size distribution and clay mineral content of the feldspar, calvert, ball, and jordan soils. In general, the ball, calvert, and jordan soils were primarily clay size particles composed of kaolinite and illite whereas the feldspar soil was primarily silt-size particles composed of quartz and feldspar minerals.

Spatial and seasonal dynamics of surface soil carbon in the Luquillo Experimental Forest, Puerto Rico.

Treesearch

Hongqing Wang; Joseph D. Cornell; Charles A.S. Hall; David P. Marley

2002-01-01

We developed a spatially-explicit version of the CENTURY soil model to characterize the storage and flux of soil organic carbon (SOC, 0–30 cm depth) in the Luquillo Experimental Forest (LEF), Puerto Rico as a function of climate, vegetation, and soils. The model was driven by monthly estimates of average air temperature, precipitation, and potential evapotranspiration...

Use of pyrolysis molecular beam mass spectrometry (py-MBMS) to characterize forest soil carbon: method and preliminary results

Treesearch

K.A. Magrini; R.J. Evans; C.M. Hoover; C.C. Elam; M.F. Davis

2002-01-01

The components of soil organic matter (SOM) and their degradation dynamics in forest soils are difficult to study and thus poorly understood,due to time-consuming sample collection, preparation, and difficulty of analyzing and identifying major components. As a result, changes in soil organic matter chemical composition as a function of age, forest type, or disturbance...

The Study of Soil Protection in the System of the Cultivated Lands of Kemerovo Region

NASA Astrophysics Data System (ADS)

Yakovchenko, M. A.; Konstantinova, O. B.; Kosolapova, A. A.

2015-09-01

The heavy metal content in the surface soils is characterized with their ingress for the given period of time. The sources of heavy metals in the soil are precipitation, seeds, dust, organic and mineral fertilizers, and others. The paper studies the heavy metal content in the soils of the waste dumps of the open-pit coal mines.

Cultivable bacterial diversity along the altitudinal zonation and vegetation range of tropical Eastern Himalaya.

PubMed

Lyngwi, Nathaniel A; Koijam, Khedarani; Sharma, D; Joshi, S R

2013-03-01

The Northeastern part of India sprawls over an area of 262 379km2 in the Eastern Himalayan range. This constitutes a biodiversity hotspot with high levels of biodiversity and endemism; unfortunately, is also a poorly known area, especially on its microbial diversity. In this study, we assessed cultivable soil bacterial diversity and distribution from lowlands to highlands (34 to 3 990m.a.s.l.). Soil physico-chemical parameters and forest types across the different altitudes were characterized and correlated with bacterial distribution and diversity. Microbes from the soil samples were grown in Nutrient, Muller Hinton and Luria-Bertani agar plates and were initially characterized using biochemical methods. Parameters like dehydrogenase and urease activities, temperature, moisture content, pH, carbon content, bulk density of the sampled soil were measured for each site. Representative isolates were also subjected to 16S rDNA sequence analysis. A total of 155 cultivable bacterial isolates were characterized which were analyzed for richness, evenness and diversity indices. The tropical and sub-tropical forests supported higher bacterial diversity compared to temperate pine, temperate conifer, and sub-alpine rhododendron forests. The 16S rRNA phylogenetic analysis revealed that Firmicutes was the most common group followed by Proteobacreria and Bacteroidetes. Species belonging to the genera Bacillus and Pseudomonas were the most abundant. Bacterial CFU showed positive but insignificant correlation with soil parameters like pH (r=0.208), soil temperature (r=0.303), ambient temperature (r=0.443), soil carbon content (r=0.525), soil bulk density (r=0.268), soil urease (r=0.549) and soil dehydrogenase (r=0.492). Altitude (r=-0.561) and soil moisture content (r=-0.051) showed negative correlation. Altitudinal gradient along with the vegetation and soil physico-chemical parameters were found to influence bacterial diversity and distribution. This study points out that this is a biome with a vast reservoir of bacteria which decrease with increasing altitudes, and highlights the microbiological importance of the poorly studied Eastern Himalayan range, justifying efforts to explore the prevalence of novel species in the biome.

Assessing pollutions of soil and plant by municipal waste dump

NASA Astrophysics Data System (ADS)

Liu, Changli; Zhang, Yun; Zhang, Feng'e.; Zhang, Sheng; Yin, Miying; Ye, Hao; Hou, Hongbing; Dong, Hua; Zhang, Ming; Jiang, Jianmei; Pei, Lixin

2007-04-01

Research is few in the literature regarding the investigation and assessment of pollutions of soil and plant by municipal waste dumps. Based upon previous work in seven waste dumping sites (nonsanitary landfills) in Beijing, Shanghai and Shijiazhuang, this study expounds the investigation and assessment method and report major pollutants. Using relative background values, this study assesses soil pollution degree in the seven dumping sites. Preliminary conclusions are: (1) pollution degrees are moderate or heavy; (2) pollution distance by domestic waste that is dumped on a plane ground is 85 m; (3) the horizontal transport distance of pollutants might be up to 120 m if waste leachates are directly connected with water in saturated soils; (4) vertical transport depth is about 3 m in unsaturated silty clayey soils. Furthermore, using relative background values and hygiene standards of food and vegetable this study assesses the pollutions of different parts of reed, sorghum, watermelon and sweet-melon. It is found: (1) in comparison with the relative background values in a large distance to the waste dumping sites, domestic wastes have polluted the roots and stems of reed and sorghum, whereas fine coal ash has polluted the leaves, rattans and fruits of watermelon and sweet-melon; (2) domestic wastes and fine coal ash have heavily polluted the edible parts of sorghum, water melon and sweet-melon. As, Hg, Pb and F have far exceeded standard values, e.g., Hg has exceeded the standard value by up to 650 1,700 times and Cd by 120 275 times, and the comprehensive pollution index is up to 192.9 369.7; (3) the polluted sorghum, watermelon and sweet-melon are inedible.

Field Sampling Plan for Closure of the Central Facilities Area Sewage Treatment Plant Lagoon 3 and Land Application Area

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Michael George

This field sampling plan describes sampling of the soil/liner of Lagoon 3 at the Central Facilities Area Sewage Treatment Plant. The lagoon is to be closed, and samples obtained from the soil/liner will provide information to determine if Lagoon 3 and the land application area can be closed in a manner that renders it safe to human health and the environment. Samples collected under this field sampling plan will be compared to Idaho National Laboratory background soil concentrations. If the concentrations of constituents of concern exceed the background level, they will be compared to Comprehensive Environmental Response, Compensation, and Liabilitymore » Act preliminary remediation goals and Resource Conservation and Recovery Act levels. If the concentrations of constituents of concern are lower than the background levels, Resource Conservation and Recovery Act levels, or the preliminary remediation goals, then Lagoon 3 and the land application area will be closed. If the Resource Conservation and Recovery Act levels and/or the Comprehensive Environmental Response, Compensation, and Liability Act preliminary remediation goals are exceeded, additional sampling and action may be required.« less

The effect of soil on cork quality.

PubMed

Pestana, Miguel N; Gomes, Alberto A

2014-01-01

The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers. Cork sampling was made in eight Cork oak stands (montados de sobreiro) located in the Plio-Plistocene sedimentary formations of Península de Setúbal in southern Tagus River region. The samples used to classify the cork as stopper for wine bottles were obtained in eight cork oak stands, covering soils of different types of sandstones of the Plio-plistocene. In each stand, we randomly chose five circular plots with 30 m radius and five trees per plot with same stripping conditions determined by: dendrometric features (HD- height stipping, PBH- perimeter at breaster height), trees vegetative condition (defoliation degree); stand features (density, percentage canopy cover); site conditions (soil type and orientation). In the center of each plot a pit was open to characterize the soil profile and to classify the soil. Cork quality for stoppers was evaluated according to porosity, pores/per cm(2) and cork boards thickness. The soil was characterized according to morphological soil profile features (lithology, soil profound, and soil horizons) and chemical soil surface horizon features (organic matter, pH, macro, and micronutrients availability). Based on the variables studied and using the numerical taxonomy, we settled relationships between the cork quality and some soil features. The results indicate: (1) high correlation between the cork caliber and boron, cation exchange capacity, total nitrogen, exchange acidity, and exchangeable magnesium, potassium, calcium, and sodium in soils of theirs cork oaks; (2) the cork porosity is correlated with the number of pores/cm(2) and magnesium soil content; (3) the other soil features have a lower correlation with the caliber, porosity, and the number of pores per cm(2).

Characterizing Zinc Speciation in Soils from a Smelter-Affected Boreal Forest Ecosystem.

PubMed

Hamilton, Jordan G; Farrell, Richard E; Chen, Ning; Feng, Renfei; Reid, Joel; Peak, Derek

2016-03-01

HudBay Minerals, Inc., has mined and/or processed Zn and Cu ore in Flin Flon, MB, Canada, since the 1930s. The boreal forest ecosystem and soil surrounding these facilities have been severely impacted by mixed metal contamination and HSO deposition. Zinc is one of the most prevalent smelter-derived contaminants and has been identified as a key factor that may be limiting revegetation. Metal toxicity is related to both total concentrations and speciation; therefore, X-ray absorption spectroscopy and X-ray fluorescence mapping were used to characterize Zn speciation in soils throughout the most heavily contaminated areas of the landscape. Zinc speciation was linked to two distinct soil types. Group I soils consist of exposed soils in weathered positions of bedrock outcrops with Zn present primarily as franklinite, a (ZnFeO) spinel mineral. Group II soils are stabilized by an invasive metal-tolerant grass species, with Zn found as a mixture of octahedral (Fe oxides) and tetrahedral Mn oxides) adsorption complexes with a franklinite component. Soil erosion influences Zn speciation through the redistribution of Zn and soil particulates from Group I landscape positions to Group II soils. Despite Group II soils having the highest concentrations of CaCl-extractable Zn, they support metal-tolerant plant growth. The metal-tolerant plants are probably preferentially colonizing these areas due to better soil and nutrient conditions as a result of soil deposition from upslope Group I areas. Zinc concentration and speciation appears to not influence the colonization by metal-tolerant grasses, but the overall soil properties and erosion effects prevent the revegetation by native boreal forest species. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

The effect of soil on cork quality

PubMed Central

Pestana, Miguel N.; Gomes, Alberto A.

2014-01-01

The present work aimed to contribute for a better knowledge regarding soil features as cork quality indicators for stoppers. Cork sampling was made in eight Cork oak stands (montados de sobreiro) located in the Plio-Plistocene sedimentary formations of Península de Setúbal in southern Tagus River region. The samples used to classify the cork as stopper for wine bottles were obtained in eight cork oak stands, covering soils of different types of sandstones of the Plio-plistocene. In each stand, we randomly chose five circular plots with 30 m radius and five trees per plot with same stripping conditions determined by: dendrometric features (HD- height stipping, PBH- perimeter at breaster height), trees vegetative condition (defoliation degree); stand features (density, percentage canopy cover); site conditions (soil type and orientation). In the center of each plot a pit was open to characterize the soil profile and to classify the soil. Cork quality for stoppers was evaluated according to porosity, pores/per cm2 and cork boards thickness. The soil was characterized according to morphological soil profile features (lithology, soil profound, and soil horizons) and chemical soil surface horizon features (organic matter, pH, macro, and micronutrients availability). Based on the variables studied and using the numerical taxonomy, we settled relationships between the cork quality and some soil features. The results indicate: (1) high correlation between the cork caliber and boron, cation exchange capacity, total nitrogen, exchange acidity, and exchangeable magnesium, potassium, calcium, and sodium in soils of theirs cork oaks; (2) the cork porosity is correlated with the number of pores/cm2 and magnesium soil content; (3) the other soil features have a lower correlation with the caliber, porosity, and the number of pores per cm2. PMID:25353015

Microbial Biomarkers for Native and Agricultural Soil Inputs to Atmospheric Particulate Matter

NASA Astrophysics Data System (ADS)

Fulton, J. M.; Herckes, P.; Fraser, M. P.; Collins, J.; Van Mooy, B. A.

2017-12-01

Intense dust storms (haboobs) erode desert soils and cause dramatic short-term increases in particulate matter (PM) concentration in the atmosphere. Background atmospheric PM levels in the southwestern United States also commonly exceed the National Ambient Air Quality Standards, so episodic haboobs and normal weather patterns both contribute to aeolian transport. We analyzed fine (PM2.5) and coarse (PM>2.5) dust fractions sampled in Tempe, Arizona for molecular biomarkers indicative of dust sourced from either native or agricultural soils. We focused on pigments and intact polar lipids (IPLs) that were also in soil crusts collected in the region. The PM samples were taken during two weeks (23 July to 5 August 2014) that included two haboobs during the first week and mostly calm weather with minor rainfall during the second week. We detected scytonemin, a diagnostic pigment biomarker for cyanobacteria, in all PM>2.5 samples, but its concentration was highest in haboob dust. Similarly, scytonemin was only abundant in PM2.5 samples taken during haboobs. Scytonemin is an important component of native biological soil crusts, protecting the crust community from UV radiation, and is ca. two orders of magnitude less abundant in disturbed agricultural soils. In biological soil crusts, scytonemin is associated with extracellular polysaccharides that are produced by cyanobacteria and bind soil into cohesive crusts. The association between scytonemin and haboobs suggests that native soil erosion is facilitated by high energy, episodic events that overcome crust cohesion. IPLs were abundant in agricultural soil crusts and included phosphatidylethanolamine from soil bacteria and a glucosylceramide from fungi. These compounds had similar concentration in haboob and background dust, suggesting agricultural or otherwise disturbed soils contribute more to ambient dust. In this study, we employed a new high resolution mass spectrometric method that produces molecular formulas and structural information, even at very low abundance. Employing this analysis on atmospheric PM improves our understanding of mechanisms by which soil crust biomarkers are transferred to lake and ocean sediments and can also contribute to source apportionment models for describing atmospheric dust contamination.

Hydrologic restoration in a dynamic subtropical mangrove-to-marsh ecotone

USGS Publications Warehouse

Howard, Rebecca J.; Day, Richard H.; Krauss, Ken W.; From, Andrew S.; Allain, Larry K.; Cormier, Nicole

2017-01-01

Extensive hydrologic modifications in coastal regions across the world have occurred to support infrastructure development, altering the function of many coastal wetlands. Wetland restoration success is dependent on the existence of hydrologic regimes that support development of appropriate soils and the growth and persistence of wetland vegetation. In Florida, United States, the Comprehensive Everglades Restoration Program (CERP) seeks to restore, protect, and preserve water resources of the greater Everglades region. Herein we describe vegetation dynamics in a mangrove-to-marsh ecotone within the impact area of a CERP hydrologic restoration project currently under development. Vegetation communities are also described for a similar area outside the project area. We found that vegetation shifts within the impact area occurred over a 7-year period; cover of herbaceous species varied by location, and an 88% increase in the total number of mangrove seedlings was documented. We attribute these shifts to the existing modified hydrologic regime, which is characterized by a low volume of freshwater sheet flow compared with historical conditions (i.e. before modification), as well as increased tidal influence. We also identified a significant trend of decreasing soil surface elevation at the impact area. The CERP restoration project is designed to increase freshwater sheet flow to the impact area. Information from our study characterizing existing vegetation dynamics prior to implementation of the restoration project is required to allow documentation of long-term project effects on plant community composition and structure within a framework of background variation, thereby allowing assessment of the project's success in restoring critical ecosystem functions.