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Sample records for olivier silt loam

  1. Transport of atrazine and dicamba through silt and loam soils

    Science.gov (United States)

    Tindall, James A.; Friedel, Michael J.

    2016-01-01

    The objectives of this research were to determine the role of preferential flow paths in the transport of atrazine (2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine) and dicamba (3-6-dichloro-2-methoxybenzoic acid) through silt and loam soils overlying the High Plains aquifer in Nebraska. In a previous study, 3 of 6 study areas demonstrated high percentages of macropores; those three areas were used in this study for analysis of chemical transport. As a subsequent part of the study, 12 intact soil cores (30-cm diameter by 40-cm height), were excavated sequentially, two from each of the following depths: 0-40cm and 40-80cm. These cores were used to study preferential flow characteristics using dye staining and to determine hydraulic properties. Two undisturbed experimental field plots, each with a 3-m2 surface area, were installed in three study areas in Nebraska. Each was instrumented with suction lysimeters and tensiometers at depths of 10cm to 80cm in 10-cm increments. Additionally, each plot was planted with corn (Zea mays). A neutron probe access tube was installed in each plot to determine soil w ater content at 15-cm intervals. All plots were enclosed w ith a raised frame (of 8-cm height) to prevent surface runoff. All suction lysimeters were purged monthly for three months and were sampled immediately prior to pre-plant herbicide application to obtain background chemical concentrations. Atrazine and dicamba moved rapidly through the soil, but only after a heavy rainfall event, probably owing to the presence of preferential flow paths and lack of microbial degradation in these soil areas. Staining of laboratory cores showed a positive correlation between the percent area stained by depth and the subsequent breakthrough of Br- in the laboratory and leaching of field-applied herbicides owing to large rainfall events. Suction lysimeter samples in the field showed increases in concentrations of herbicides at depths where laboratory data indicated greater

  2. Degradation of roxarsone in a silt loam soil and its toxicity assessment.

    Science.gov (United States)

    Liang, Tengfang; Ke, Zhengchen; Chen, Qing; Liu, Li; Chen, Guowei

    2014-10-01

    The land application of poultry or swine litter, containing large amounts of roxarsone, causes serious arsenic pollution in soil. Understanding biotransformation process of roxarsone and its potential risks favors proper disposal of roxarsone-contaminated animal litter, yet remains not achieved. We report an experimental study of biotransformation process of roxarsone in a silt loam soil under various soil moisture and temperature conditions, and the toxicity of roxarsone and its products from degradation. Results showed that soil moisture and higher temperature promoted roxarsone degradation, associating with emergent pentavalent arsenic. Analysis of fluorescein diacetate (FDA) hydrolysis activity revealed that roxarsone does not exert acute toxic on soil microbes. With the release of inorganic arsenic, FDA hydrolysis activity was inhibited gradually, as evidenced by ecotoxicological assessment using Photobacterium leiognathi. The results shade new lights on the dynamic roxarsone biotransformation processes in soil, which is important for guiding appropriate disposal of poultry or swine litter in the environment. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Soil nitrogen dynamics and Capsicum Annuum sp. plant response to biochar amendment in silt loam soil

    Science.gov (United States)

    Horel, Agota; Gelybo, Gyorgyi; Dencso, Marton; Toth, Eszter; Farkas, Csilla; Kasa, Ilona; Pokovai, Klara

    2017-04-01

    The present study investigated the growth of Capsicum Annuum sp. (pepper) in small-scale experiment to observe changes in plant growth and health as reflected by leaf area, plant height, yield, root density, and nitrogen usage. Based on field conditions, part of the study aimed to examine the photosynthetic and photochemical responses of plants to treatments resulting from different plant growth rates. During the 12.5 week long study, four treatments were investigated with biochar amount of 0, 0.5%, 2.5%, and 5.0% (by weight) added to silt loam soil. The plants were placed under natural environmental conditions, such that photosynthetic activities from photosynthetically active radiation (PAR) and the plants photochemical reflectance index (PRI) could be continuously measured after exposure to sunlight. In this study we found that benefits from biochar addition to silt loam soil most distinguishable occurred in the BC2.5 treatments, where the highest plant yield, highest root density, and highest leaf areas were observed compared to other treatments. Furthermore, data showed that too low (0.5%) or too high (5.0%) biochar addition to the soil had diminishing effects on Capsicum Annuum sp. growth and yield over time. At the end of the 12th week, BC2.5 had 22.2%, while BC0.5 and BC5.0 showed 17.4% and 15.7% increase in yield dry weight respectively compared to controls. The collected data also showed that the PRI values of plants growing on biochar treated soils were generally lower compared to control treatments, which could relate to leaf nitrogen levels. Total nitrogen amount showed marginal changes over time in all treatments. The total nitrogen concentration showed 28.6% and 17.7% increase after the 6th week of the experiment for BC2.5 and BC5.0, respectively, while inorganic nutrients of NO3-N and NH4+-N showed a continuous decrease during the course of the study, with a substantial drop during the first few weeks. The present study provides evidence for impact

  4. Combined mild soil washing and compost-assisted phytoremediation in treatment of silt loams contaminated with copper, nickel, and chromium.

    Science.gov (United States)

    Sung, Menghau; Lee, Chi-Yi; Lee, Suen-Zone

    2011-06-15

    A new soil remediation option, combining the soil washing process using pure water followed by the compost-assisted phytoextraction, is evaluated using silt loams contaminated with plating wastewater containing Cu, Ni, and Cr. Plants utilized in this study are the rapeseeds, sunflowers, tomatoes, and soapworts. Phytoextraction operation was carried out in pot experiments over a period of 4 months. Metal concentrations in roots and shoots of plants were analyzed upon completion of each pot experiment. Hypothesis testing was employed in assessing the significance of difference in the experimental data. Results indicated that the rapeseed, a hyperaccumulator, is most effective in extracting metals from the compost-amended silt loams. The fast-growing sunflowers and tomatoes are comparable to rapeseeds in accumulating metals despite their relatively low metal concentrations in tissues. Bioaccumulation coefficients obtained for all plants are less than one, indicating that phytostabilization rather than phytoextraction is the dominant mechanism at this simulated final-phase condition. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Microbial functional diversity responses to 2 years since biochar application in silt-loam soils on the Loess Plateau.

    Science.gov (United States)

    Zhu, Li-Xia; Xiao, Qian; Shen, Yu-Fang; Li, Shi-Qing

    2017-10-01

    The structure and function of soil microbial communities have been widely used as indicators of soil quality and fertility. The effect of biochar application on carbon sequestration has been studied, but the effect on soil microbial functional diversity has received little attention. We evaluated effects of biochar application on the functional diversities of microbes in a loam soil. The effects of biochar on microbial activities and related processes in the 0-10 and 10-20cm soil layers were determined in a two-year experiment in maize field on the Loess Plateau in China. Low-pyrolysis biochar produced from maize straw was applied into soils at rates of 0 (BC0), 10 (BC10) and 30 (BC30)tha -1 . Chemical analysis indicated that the biochar did not change the pH, significantly increased the amounts of organic carbon and nitrogen, and decreased the amount of mineral nitrogen and the microbial quotient. The biochar significantly decreased average well colour development (AWCD) values in Biolog EcoPlates™ for both layers, particularly for the rate of 10tha -1 . Biochar addition significantly decreased substrate richness (S) except for BC30 in the 0-10cm layer. Effects of biochar on the Shannon-Wiener index (H) and Simpson's dominance (D) were not significant, except for a significant increase in evenness index (E) in BC10 in the 10-20cm layer. A principal component analysis clearly differentiated the treatments, and microbial use of six categories of substrates significantly decreased in both layers after biochar addition, although the use of amines and amides did not differ amongst the three treatments in the deeper layer. Maize above ground dry biomass and height did not differ significantly amongst the treatments, and biochar had no significant effect on nitrogen uptake by maize seedlings. H was positively correlated with AWCD, and negatively with pH. AWCD was positively correlated with mineral N and negatively with pH. Our results indicated that shifts in soil

  6. Cultivos de cobertura: efectos sobre la macroporosidad y la estabilidad estructural de un suelo franco-limoso Cover crops: effects on soil macroporosity and soil structural stability in a silt loam soil

    Directory of Open Access Journals (Sweden)

    María Florencia Varela

    2011-07-01

    Full Text Available Los suelos franco-limosos manejados con siembra directa a menudo poseen porosidad estructural baja e inestable. Con el objetivo de determinar la capacidad de los cultivos de cobertura (CC de mejorar la porosidad y estabilidad estructural de estos suelos se llevaron a cabo experimentos de campo y de invernáculo. Ambos tuvieron tratamientos con y sin CC (avena, Avena sativa L., en rotación con soja (Glicine max L. Merr.. Luego de los CC se midieron densidad aparente (DA, el índice de inestabilidad estructural (IE y en el ensayo de invernáculo además, se midió la evolución de la distribución de tamaño de poros (DTP. En ambos ensayos la introducción de CC no disminuyó la DA, aunque incrementó la estabilidad del suelo (PNo- till (NT silt loam topsoils have often a low and unstable structural porosity. The objective of this study was to determine the capability of cover crops (CC of improving the structural porosity and stability of silt loam soils under NT. Greenhouse and field experiments were carried out on a silt loam soil (Typic Argiudoll with and without CC (oat, Avena sativa L. in crop sequences with soybean (Glicine max L. Merr.. Soil bulk density (DA and aggregate instability index (IE were measured after the CC in both experiments. In the greenhouse experiment, soil pore size distribution (DTP was measured. The use of CC did not change DA, but soil IE was significantly lower in crop sequences with CC (P < 0.05 both under field and greenhouse conditions. Stability increases were likely due to the effect of CC residues and root mass. No differences in DTP were found between treatments, although a significant effect of sampling date was observed (P<0.05. Changes in DTP were due to significant increases in mesopore (517.5% and macropore (52.7% volumes. Such changes occurred in all the treatments, probably due to the soil wetting-drying cycles. The results found in this study agree with other studies carried out on silt loams in the

  7. Olivier's 'Essay on Hamlet'

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    Koprivica Zoran

    2017-01-01

    Full Text Available Laurence Olivier's Hamlet is more a renaissance character, a melancholic and a daydreamer, than a man of action, unlike his Henry V and Richard III film adaptations. However, it seems that Olivier showed outstanding courage not in his extremely liberal approach to interpreting this Shakespeare's tragedy, but in literal application of Freud's model on his inner problems, seen through the prism of the professor Ernest Johnson. Transposing Shakespeare's original text, starting with its global features, he abstracts numerous and diversified eventful and associative moments which might burden the polyphonic structure of his own - film story. Moreover, Olivier wants to avoid its dramatic deconstruction and focuses the viewer's attention to the climactic moments. However, dramatically the strongest and most effective scenes in his film adaptation of Hamlet are the ones related to the use of camera, that is to say, its movement and analyticity. The intention was to point not only to the ostentatious difference between cinematographic and theatrical stylisation, but, to a certain extent, he defines the viewer's standpoint. In his 'essay on Hamlet', Olivier does not consider chronology, that is to say, the problem of temporal relations. The visual structure of the film and its dynamics are determined a priori by the rhythmic parameters of the Elsinore's labyrinthic space.

  8. Advance of Wetting Front in Silt Loam Soil

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    Mohamed Mahmood

    2013-04-01

    Full Text Available Under drip irrigation , the plant's root is concentrated inside the wetted bulb (region. Thus, the development of these roots and the plant production are greatly affected by the wetting pattern. Therefore, the wetting pattern of soil under drip irrigation must be taken into consideration in the design of drip irrigation system for both single dripping source or multi-overlapping wetting patterns of dripping water sources.2The aim of this study is to evaluate the effect of initial water content of the soil and spacing between two adjacent dripping sources with different flow rate on the movement of the wetting front.This study included 16 tests for monitoring the advancement of the wetting front with time during and after the water application phase. The water advance and water distribution measurement are carried out for two cases of the soil profile: for the first case with initial volumetric water content of 4.08% and for the second case with initial volumetric water content of 12.24%. Two spacing between the emitter were tested 25cm and 50 cm using application flow rates of 0.606, 1.212, 1.818, and 2.424 cm3 /min/cm to show the combined effect of spacing and flow rate on the performance of two adjacent emitter.The study proposed a method for determining the spacing between the two emitting sources , the water application rate and watering time. The proposed method depends on a wetted zone whose depth is equal to the root zone depth with a values equals to the maximum vertical advance of the wetting front underneath the drip line at time when this depth is equal to the depth of wetting at mid­point between the drip line. the study revealed that both the vertical water advance in soil underneath the emitter and the horizontal advance of the wetting front is larger than those in the case of single emitter.Furthermore, the vertical water advance increases with the decrease spacing between the two drip lines. Also, the horizontal advance of the wetting front is not affected by varying this spacing for both studied cases of initial water content.

  9. Enhanced isoproturon mineralisation in a clay silt loam agricultural soil

    OpenAIRE

    El-Sebai , T.; Lagacherie , B.; Cooper , J.F.; Soulas , G.; Martin-Laurent , F.

    2005-01-01

    International audience; 14C-ring-labelled isoproturon mineralisation was investigated in a French agricultural soil previously exposed to isoproturon. 50 different soil samples collected every 2 m along a transect of 100 m in length were treated one or two times with isoproturon under laboratory conditions and analysed by radiorespirometry. 94% of the soil samples showed a high ability to mineralise isoproturon with a relatively low variability in the cumulative percentage of mineralisation r...

  10. L’olivier au Maroc

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    El Mouhtadi Issam

    2014-03-01

    Full Text Available L’olivier est une culture traditionnelle sur le pourtour de la Méditerranée. Il est donc naturel de trouver cet arbre au Maroc où il est présent depuis des siècles. Cultivé surtout traditionnellement jusqu’à ses dernières années, il fait l’objet maintenant d’un plan de valorisation très ambitieux pour non seulement garder le Royaume à son niveau actuel (2e producteur mondial pour l’olive de conserve et 6e pour l’huile d’olive mais pour conquérir de nouveaux marchés au niveau mondial et profiter ainsi de l’engouement que connaît cette huile reconnue pour ses bienfaits. Le plan national « Maroc Vert » permet ainsi, grâce à des subventions conséquentes, non seulement de renouveler les vergers existant avec la variété traditionnelle picholine du Maroc, mais également la plantation de nouvelles variétés en super-intensif dans le but d’industrialiser au maximum de nouveaux vergers. Il en est de même pour la transformation des olives en huile de bonne qualité avec la mise en place d’unités de trituration modernes qui doivent supplanter à terme la multitude de « maâsra » et réduire ainsi l’impact environnemental dû aux margines. L’olive ne sera plus dans l’avenir que représentée par son huile et ses formes comestibles, mais les résidus de son extraction seront valorisés soit sous forme de combustible élaboré pour le grignon, soit sous forme d’une base de chimie verte pour les sous-produits du raffinage. D’autres applications sont actuellement à l’étude, car le Maroc à compris, comme tous les autres grands pays producteurs, que l’olive était un nouveau gisement de richesses.

  11. 2763-IJBCS-Article-Tandji Olivier Amoussou

    African Journals Online (AJOL)

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    Olivier AMOUSSOU exprime également sa gratitude à l'endroit de l'Union Européenne ... West African estuaries and lagoons, is also a good candidate for promoting tilapia farming. ...... Cichlidae) from coastal areas in West ... Rio de Janeiro;.

  12. Olivier Chesneau's Work on Low Mass Stars

    Science.gov (United States)

    Lagadec, E.

    2015-12-01

    During his too short career, Olivier Chesneau pioneered the study of the circumstellar environments of low mass evolved stars using very high angular resolution techniques. He applied state of the art high angular resolution techniques, such as optical interferometry and adaptive optics imaging, to the the study of a variety of objects, from AGB stars to Planetary Nebulae, via e.g. Born Again stars, RCB stars and Novae. I present here an overview of this work and most important results by focusing on the paths he followed and key encounters he made to reach these results. Olivier liked to work in teams and was very strong at linking people with complementary expertises to whom he would communicate his enthusiasm and sharp ideas. His legacy will live on through the many people he inspired.

  13. MNB panel discussion with Olivier Blanchard

    OpenAIRE

    Olivier J. Blanchard; Péter Benczúr

    2013-01-01

    A citizen of France, Olivier Blanchard has spent his professional life in Cambridge, U.S. After obtaining his PhD in economics at the Massachusetts Institute of Technology in 1977, he taught at Harvard University, returning to MIT in 1982, where he has been since then. He is the Class of 1941 Professor of Economics, and a former Chair of the Economics Department. He is currently on leave from MIT, as Economic Counsellor and Director of the Research Department of the International Monetary Fun...

  14. Clinoptilolite zeolite influence on inorganic nitrogen in silt loam and sandy agricultural soils

    Science.gov (United States)

    Development of best management practices can help improve inorganic nitrogen (N) availability to plants and reduce nitrate-nitrogen (NO3-N) leaching in soils. This study was conducted to determine the influence of the zeolite mineral Clinoptilolite (CL) additions on NO3-N and ammonium-nitrogen (NH4...

  15. Estimating Infiltration Rates for a Loessal Silt Loam Using Soil Properties

    Science.gov (United States)

    M. Dean Knighton

    1978-01-01

    Soil properties were related to infiltration rates as measured by single-ringsteady-head infiltometers. The properties showing strong simple correlations were identified. Regression models were developed to estimate infiltration rate from several soil properties. The best model gave fair agreement to measured rates at another location.

  16. Soil structure and earthworm activity in an marine silt loam under pasture versus arable land

    NARCIS (Netherlands)

    Jongmans, A.G.; Pulleman, M.M.; Marinissen, J.C.Y.

    2001-01-01

    Agricultural management influences soil organic matter (SOM) and earthworm activity which interact with soil structure. We aimed to describe the change in earthworm activity and related soil (micro)structure and SOM in a loamy Eutrodept as affected by permanent pasture (PP) and conventional arable

  17. Gagaku, de Olivier Messiaen Messiaen's Gagaku

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    Luigi Antonio Irlandini

    2012-06-01

    Full Text Available A tensão entre nostalgia e inovação se manifesta de maneira única em Gagaku, o quarto movimento de Sept Haikai, de Olivier Messiaen. A religiosidade de Messiaen representa uma forma de nostalgia para a vanguarda intelectual francesa. Messiaen considera o senso de ritual e de estase como expressões musicais do sagrado. Através da comparação da estrutura do Gagaku de Messiaen (analisado à luz de seus próprios escritos sobre os seus métodos composicionais e da estrutura da música tradicional japonesa gagaku, este artigo mostra de que modo o senso de ritual e de estase constitui o elemento estético comum existente independentemente em ambas as formas musicais. A existência de um elemento comum entre a "fonte" não-ocidental e a composição ocidental inspirada por esta fonte provê a condição necessária para a transformação de nostalgia em inovação. O conceito de écriture tem um papel importante na dialética de passado/futuro desta transformação, causando estrutura e estilo a se diferenciarem baseados no princípio da não-imitação, e afirmando-se como o elemento formativo que faz de Gagaku uma peça distintamente francesa.The tension between nostalgia and innovation is uniquely manifested in Olivier Messiaen's Gagaku, the fourth movement of his 1962 composition Sept Haikai. Messiaen's religiosity represented a form of nostalgia to the intellectual French Avant-Garde. Messiaen considers the sense of ritual and stasis as musical expressions of sacredness. By comparing the structure of Messiaen's Gagaku (analyzed in the light of his writings about his compositional methods and that of ancient Japanese gagaku court music, this paper will show how this sense of ritual and stasis constitutes the aesthetic common ground existing independently in both forms. The existence of common elements between a non-western "source" and the western composition inspired by that source provides the necessary condition for the transformation of

  18. Allelopathic potential of populus euphratica olivier

    International Nuclear Information System (INIS)

    Sher, Z.; Hussain, F.; Ahmad, B.; Wahab, M.

    2011-01-01

    Populus euphratica Olivier is frequently cultivated deciduous tree in Pakistan on agricultural land for its shade, fodder, timber and fuel wood. A relatively reduced under storey is often observed below it. Therefore the present study was conducted to assess the allelopathic potential of Populus euphratica against some crop species. Plant material of Populus euphratica were collected from the agriculture fields of Lahor, District Swabi in 2008 and were dried at room temperature (258 deg. C-308 deg. C). Allelopathic studies conducted by using aqueous extracts from various parts including young leaves, mature leaves, bark, litter and mulching in various experiments invariably retarded the germination, plumule, radical growth, fresh and dry weight of Sorghum vulgare Perse, Setaria italica (L.) P. Beauv and Triticum aestivum L., in laboratory experiments. The aqueous extracts obtained after 48 h were more inhibitory than 24 h. Leaves were more toxic than bark. Litter and mulching experiments also proved to be inhibitory. It is suggested that the various assayed parts of Populus euphratica have strong allelopathic potential at least against the tested species. Further investigation is required to see its allelopathic behavior under field condition against its associated species and to identify the toxic principles. (author)

  19. EFFECTS OF ALKALINE SANDY LOAM ON SULFURIC SOIL ACIDITY AND SULFIDIC SOIL OXIDATION

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    Patrick S. Michael

    2015-08-01

    Full Text Available  In poor soils, addition of alkaline sandy loam containing an adequate proportion of sand, silt and clay would add value by improving the texture, structure and organic matter (OM for general use of the soils. In acid sulfate soils (ASS, addition of alkaline sandy would improve the texture and leach out salts as well as add a sufficient proportion of OM for vegetation establishment. In this study, addition of alkaline sandy loam into sulfuric soil effectively increased the pH, lowered the redox and reduced the sulfate content, the magnitude of the effects dependent on moisture content. Addition of alkaline sandy loam in combination with OM was highly effective than the effects of the lone alkaline sandy loam. When alkaline sandy was added alone or in combination with OM into sulfidic soil, the effects on pH and the redox were similar as in the sulfuric soil but the effect on sulfate content was variable. The effects under aerobic conditions were higher than under anaerobic conditions. The findings of this study have important implications for the general management of ASS where lime availability is a concern and its application is limited.International Journal of Environment Volume-4, Issue-3, June-August 2015Page: 42-54

  20. Charles Olivier and the rise of meteor science

    CERN Document Server

    Taibi, Richard

    2017-01-01

    This fascinating portrait of an amateur astronomy movement tells the story of how Charles Olivier recruited a hard-working cadre of citizen scientists to rehabilitate the study of meteors. By 1936, Olivier and members of his American Meteor Society had succeeded in disproving an erroneous idea about meteor showers. Using careful observations, they restored the public’s trust in predictions about periodic showers and renewed respect for meteor astronomy among professional astronomers in the United States. Charles Olivier and his society of observers who were passionate about watching for meteors in the night sky left a major impact on the field. In addition to describing Olivier’s career and describing his struggles with competitive colleagues in a hostile scientific climate, the author provides biographies of some of the scores of women and men of all ages who aided Olivier in making shower observations, from the Leonids and Perseids and others. Half of these amateur volunteers were from 13 to 25 years of...

  1. Silt-clay aggregates on Mars

    International Nuclear Information System (INIS)

    Greeley, R.

    1979-01-01

    Viking observations suggest abundant silt and clay particles on Mars. It is proposed that some of these particles agglomerate to form sand size aggregates that are redeposited as sandlike features such as drifts and dunes. Although the binding for the aggregates could include salt cementation or other mechanisms, electrostatic bonding is considered to be a primary force holding the aggregates together. Various laboratory experiments conducted since the 19th century, and as reported here for simulated Martian conditions, show that both the magnitude and sign of electrical charges on windblown particles are functions of particle velocity, shape and composition, atmospheric pressure, atmospheric composition, and other factors. Electrical charges have been measured for saltating particles in the wind tunnel and in the field, on the surfaces of sand dunes, and within dust clouds on earth. Similar, and perhaps even greater, charges are proposed to occur on Mars, which could form aggregates of silt and clay size particles. Electrification is proposed to occur within Martian dust clouds, generating silt-clay aggregates which would settle to the surface where they may be deposited in the form of sandlike structures. By analog, silt-clay dunes are known in many parts of the earth where silt-clay aggregated were transported by saltation and deposited as 'sand.' In these structures the binding forces were later destroyed, and the particles reassumed the physical properties of silt and clay, but the sandlike bedding structure within the 'dunes' was preserved. The bedding observed in drifts at the Viking landing site is suggested to result from a similar process involving silt-clay aggregates on Mars

  2. Impact of macropores and gravel outcrops on phosphorus leaching at the plot scale in silt loam soils

    Science.gov (United States)

    In response to increased nutrient loads in surface waters, scientists and engineers need to identify critical nutrient source areas and transport mechanisms within a catchment to protect beneficial uses of aquatic systems in a cost effective manner. It was hypothesized that hydrologic heterogeneitie...

  3. Linear Shrinkage Behaviour of Compacted Loam Masonry Blocks

    Directory of Open Access Journals (Sweden)

    NAWAB ALI LAKHO

    2017-04-01

    Full Text Available Walls of wet loam, used in earthen houses, generally experience more shrinkage which results in cracks and less compressive strength. This paper presents a technique of producing loam masonry blocks that are compacted in drained state during casting process in order to minimize shrinkage. For this purpose, loam masonry blocks were cast and compacted at a pressure of 6 MPa and then dried in shade by covering them in plastic sheet. The results show that linear shrinkage of 2% occurred which is smaller when compared to un-compacted wet loam walls. This implies that the loam masonry blocks compacted in drained state is expected to perform better than un-compacted wet loam walls.

  4. Interaction of radionuclides with diluvium loams

    International Nuclear Information System (INIS)

    Martyanov, V.V.; Guskov, A.V.; Tkachenko, A.V.; Prozorov, L.B.; Karlina, O.K.

    2005-01-01

    Full text of publication follows: Primary goal of this research was to study the interaction of radioactive liquid waste with diluvium loams. A geology-hydro-geological characterisation of the RADON-site facility, located in the Southern Region of Russia, is given. According to the results of laboratory and field studies, the hydro-geological parameters of diluvium loams were designed, and their mineral and grain structures were investigated. It was established, that loams have low filtration properties. Definition of filtration coefficients (Kf) under laboratory conditions has shown low values (hydraulic gradient J=10, Kf = 8.10 -4 m/day). But the field experiment has shown, that Kf values vary from 0.1 up to 0.04 m/day with a gradient of J=1! (It is important to point at the selection of the initial data for modelling migration). Mineral structure: quartz - 43 %, montmorillonite - 28 %, hydro-micas - 17 %, iron hydroxides - 5 %, feldspar - 3,7 %, kaolinite - 2 %, carbonates - 1 %, organics - 0,3 %. The content of minerals known as good sorbents, makes up to 52 %. Laboratory experiments dedicated to the determination of sorption isotherms for various radionuclides were carried out. As a result, distribution coefficients (Kd) for 90 Sr, 137 Cs, 60 Co, 238 Pu were determined. Geology-hydro-geological and radiochemical data were used for the schematization of the system. Then, the mathematical modelling and forecasting of radionuclide migration was carried out. Two conservative scenarios were considered - full destruction of the waste matrices + water flow (lateral and vertical direction). As migrating components 90 Sr, 137 Cs, 60 Co, 238 Pu were considered. 90 Sr, 137 Cs, 60 Co, 238 Pu have different mobility due to their Kd ranging from tens and hundreds up to thousand ml/g depending on the properties of the diluvium loams. Initial radionuclide concentrations were as follow: 137 Cs -1.32.10 8 Bq/l, 60 Co - 2.52.10 7 Bq/l, 90 Sr - 1.81.10 7 Bq/l, 238 Pu - 7.78.10 6

  5. Pharmacognostic studies of insect gall of Quercus infectoria Olivier (Fagaceae)

    Institute of Scientific and Technical Information of China (English)

    Savitri Shrestha; Vasuki Srinivas Kaushik; Ravi Shankara Birur Eshwarappa; Sundara Rajan Subaramaihha; Latha Muuaiah Ramanna; Dhananjaya Bhadrapura Lakkappa

    2014-01-01

    Objective:To study the detailed pharmacognostic profile of galls of Quercus infectoria Olivier (Q. infectoria olivier) (Fagaceae), an important medicinal plant used in the Indian system of medicine. Methods: Samples of galls of Q. infectoria were studied by macroscopical, microscopical, physiochemical, phytochemical, fluorescence analysis and othjer methods for standardization as recommended by WHO. Results:Macroscopically, the crude drug is globose with horny appearances on external surface (1.4-2.3 cm in length and 1-1.5 cm in diameter), with greyish-brown to brownish-black in colour externally and dark brown buff colored. Surface is smooth with numerous horny protuberances giving rough touch, and with unpleasant odour. Microscopically, a wide zone of radially elongated parenchyma cells between upper and lower epidermis were found. The vascular strands were present at all places and radially elongated sclerides touched the lower epidermis. In physico-chemical studies, the moisture, total ash, acid insoluble ash, alcohol soluble, water soluble, petroleum ether, chloroform extractive value and tannin content were found to be 2.790, 5.020, 0.110, 38.780, 41.210, 0.402, 1.590 and 49.200 percentage respectively. Preliminary phytochemical screening showed the presence of phenols, flavonoids, steroids, triterpenes, tannins, saponins and alkaloids. Conclusions:The results of the present study serve as a valuable source of information and provide suitable standards for identification of this medicinally important plant drug material for future investigations and applications.

  6. Migration of Co and Cs radionuclides through a loam soil column

    International Nuclear Information System (INIS)

    Syed Hakimi Sakuma bin Syed Ahmad; Shimooka, K.

    1990-01-01

    A soil column experiment was conducted to determine the migration of Co and Cs radionuclides through a loam soil. The different migration rates of the radionuclides at low and high concentrations were determined at pH 7. Retardation factor (Rf) both the radionuclides at low and high concentrations were determined by fitting adsorbed concentration distribution equations to observed values. The calculation shows that the Rf1=500 and Rf2=3 for Co at high and low concentrations, respectively. For Cs, the Rf1=600 and Rf2=5 at high and low concentrations, respectively. The results shows that major portions of both the radionuclides were adsorbed onto the soil layer at the top by ion exchange mechanism which resulted in the high retardation factor values. Minor portions had migrated downwards as insoluble cations, pseudocolloids and very fine silt particles resulting in the low retardation factor

  7. Water retention properties of stiff silt

    Directory of Open Access Journals (Sweden)

    Barbara Likar

    2017-06-01

    Full Text Available Recent research into the behaviour of soils has shown that it is in fact much more complex than can be described by the mechanics of saturated soils. Nowadays the trend of investigations has shifted towards the unsaturated state. Despite the signifiant progress that has been made so far, there are still a lot of unanswered questions related to the behaviour of unsaturated soils. For this reason, in the fild of geotechnics some new concepts are developed, which include the study of soil suction. Most research into soil suction has involved clayey and silty material, whereas up until recently no data have been available about measurements in very stiff preconsolidated sandy silt. Very stiff preconsolidated sandy silt is typical of the Krško Basin, where it is planned that some very important geotechnical structures will be built, so that knowledge about the behaviour of such soils at increased or decreased water content is essential. Several different methods can be used for soil suction measurements. In the paper the results of measurements carried out on very stiff preconsolidated sandy silt in a Bishop - Wesley double-walled triaxial cell are presented and compared with the results of soil suction measurements performed by means of a potentiometer (WP4C. All the measurement results were evaluated taking into account already known results given in the literature, using the three most commonly used mathematical models. Until now a lot of papers dealing with suction measurements in normal consolidated and preconsolidated clay have been published. Measurements on very stiff preconsolidated sandy silt, as presented in this paper were not supported before.

  8. The genus Scaphidium Olivier in East China (Coleoptera, Staphylinidae, Scaphidiinae

    Directory of Open Access Journals (Sweden)

    Liang Tang

    2014-04-01

    Full Text Available A review of 21 species of Scaphidium Olivier from East China is presented, including 6 new species: S. jinmingi sp. n. (Zhejiang, Anhui, Chongqing, S. crypticum sp. n.(Zhejiang, Fujian, Jiangxi, Guangxi, S. varifasciatum sp. n. (Zhejiang, An’hui, S. robustum sp. n. (Fujian, Guizhou, Chongqing, Guangxi, Yunnan, S. connexum sp. n. (Zhejiang, Fujian, Guangxi, and S. bayibini sp. n. (An’hui. New province records for S. comes Löbl, S. grande Gestro, S. sauteri Miwa & Mitono, S. formosanum Pic, S. carinense Achard, S. sinense Pic, S. delatouchei Achard, S. biwenxuani He, Tang & Li, S. klapperichi Pic, S. stigmatinotum Löbl, S. wuyongxiangi He, Tang & Li, and S. direptum Tang & Li as well as some biological notes are reported. Habitus and diagnostic characters of all species are photographed and a key to Scaphidium species of East China is provided.

  9. effect of tractor forward speed on sandy loam soil physical ...

    African Journals Online (AJOL)

    Dr Obe

    Ilorin on a sandy loam soil to evaluate the effect of the imposition of different .... of the blade is 10.5cm. ... arranged in an inverted cone shape with ... replicates were taken for each speed run. The ..... Thakur, T. C; A. Yadav; B. P. Varshney and.

  10. Effects of single and combined applications of entomopathogenic fungi and nematodes against Rhynchophorus ferrugineus (Olivier)

    Science.gov (United States)

    This study was carried out to investigate the insecticidal properties of Beauveria bassiana and Metarhizium anisopliae, and Heterorhabditis bacteriophora Poinar for their virulence against 2nd, 4th and 6th instar larvae of Rhynchophorus ferrugineus (Olivier). Both fungi were either applied alone or ...

  11. First occurrence of knight rock shrimp, Sicyonia lancifer (Olivier, 1811 (Decapoda: Sicyoniidae in the Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    A. PATANIA

    2015-01-01

    Full Text Available The occurrence of the non-native species Sicyonia lancifer  (Olivier, 1811 belonging to Sicyoniidae family is reported for the first time in the Mediterranean Sea. In the following  paper  the distinguishing features of the species are provided.

  12. Evaluation of filter fabrics for use in silt fences.

    Science.gov (United States)

    1980-01-01

    The study reported was initiated to develop tests simulating field conditions that could be used to develop information for the formulation of specifications for use in purchasing filter fabrics to be used to construct silt fences. Fifteen fabrics we...

  13. Silt: 2 62 μm, 9 4φ

    Science.gov (United States)

    Assallay, A. M.; Rogers, C. D. F.; Smalley, I. J.; Jefferson, I. F.

    1998-11-01

    The particles in finer-grained detrital sediments are usually composed of quartz. They fall into two size grades: sand (2 mm-62 μm) and silt (62 μm-2 μm). These size gradings conceal important geological processes since there are geological controls on both the quartz sand and silt populations. Sand nature is largely controlled by geochemical reactions, for example in cooling granite from which it is eventually released by weathering action. The quartz is among the last part of the rock system to solidify and the eutectic-like reaction which occurs ensures that the quartz exists as small crystalline units, each suffering considerable cooling and recrystallisation stresses. Silt is broken quartz, and has traditionally been considered to lack a specific geological control. The situation is confused by the large range of materials that fall into the size category, but there do seem to be distinguishable modes and possibly comminution limits within the 60 μm span. The controls operating in this size range are probably the critical concentration of `Moss' defects in the quartz particles. Moss postulated the formation of specific crystal defects in the quartz formed in granites. These affect sand formation and it is possible that they also control the mode size of silt particles. Within the silt range there may be several usefully definable populations, as Moss proposed for sand. The Quaternary appears to be a silt-rich period due to tectonic and glacial activity, but silt production is apparent throughout the sedimentary record. Very long-term silt producing processes are required. To produce silt in nature, on a large scale, very energetic processes are required. Many processes that are believed to generate silt particles have been listed. However, large-scale production is essentially due to glacial grinding, or to intense weathering processes in high, cold, tectonically active mountain regions. The region of High Asia (of crustal overlap) is a major generator of

  14. The dating of the fourth volume of Guillaume-Antoine Olivier's "Entomologie, ou histoire naturelle des insectes".

    Science.gov (United States)

    Bousquet, Yves

    2018-01-01

    Despite the title page is dated 1795, the fourth volume of Olivier's Entomologie, ou histoire naturelle des insectes was issued in two parts, one probably in 1795 and the second in 1800. All new taxa made available in this work have previously been dated 1795 in the literature. A list of new species described in 1795 and a list of those that have to be dated 1800 are appended. The genus Necrobia should be credited to Latreille, 1797, not Olivier, 1795.

  15. Olivier Caïra, Jeux de rôle. Les forges de la fiction

    Directory of Open Access Journals (Sweden)

    Antoine Dauphragne

    2010-06-01

    Full Text Available Les forges de la fiction, d’Olivier Caïra, est à ranger parmi les rares ouvrages francophones en sciences humaines s’attachant au jeu de rôles. L’ouvrage en propose une analyse fine et dynamique centrée sur la pratique des joueurs. La démarche annoncée, qui entend proposer un texte accessible aussi bien aux rôlistes qu’aux universitaires, semble renvoyer autant à un souci de clarté qu’au profil de l’auteur. Olivier Caïra est sociologue ; ses travaux portent sur l’industrie du divertissement e...

  16. Silt fences: An economical technique for measuring hillslope soil erosion

    Science.gov (United States)

    Peter R. Robichaud; Robert E. Brown

    2002-01-01

    Measuring hillslope erosion has historically been a costly, time-consuming practice. An easy to install low-cost technique using silt fences (geotextile fabric) and tipping bucket rain gauges to measure onsite hillslope erosion was developed and tested. Equipment requirements, installation procedures, statistical design, and analysis methods for measuring hillslope...

  17. The art of screening : Effectiveness of silt screens

    NARCIS (Netherlands)

    Radermacher, M.; Van der Goot, F.; Rijks, D.C.; De Wit, L.

    2013-01-01

    One of the potential environmental issues associated with dredging in the marine environment is the increase of suspended sediment concentrations (SSC) by generation and dispersion of sediment plumes. This can be mitigated by source control or by the installation of containment barriers like silt

  18. Strontium 90 in silts of the Dnieper cascade water reservoirs

    International Nuclear Information System (INIS)

    Romanenko, V.D.; Kuz'menko, M.I.; Matvienko, L.P.; Klenus, V.G.; Nasvit, O.I.

    1989-01-01

    The change of strontium-90 content in water and silts of the Dnieper cascade water reservoirs was analyzed. It was shown, that decrease of strontium-90 content in water in time connected basically with ion exchange adsorption of strontium-90 by residues. A high sorption ability of residues made it possible for radioisotopes to reduce sharply their concentration along depth of soils. The highest concentration of radioisotopes was in the upper layers, enriched by silt. It was ascertained, that strontium-90 migration along depth of residues took place rapidly in the Kiev's water reservoir. Down the cascade strontium-90 content reduced in lower layers of residues as well as in upper layers. 4 tabs

  19. Methodological spot of establishing silt deposit concentration in Serbian rivers

    Directory of Open Access Journals (Sweden)

    Dragićević Slavoljub

    2007-01-01

    Full Text Available Recent methodology of sampling and establishing silt deposit concentration in Serbian rivers is associated to numerous deficiencies. Daily concentrations of this type of river deposit on the most of the hydrological gauges were obtained on the base of only one measurement, which takes into consideration the matter of representative ness of those samples. Taking the samples of deposit in one point on the profile is little bit problematic because of dispersion of the obtained results. Very important matter is the question of choice of the sampling location. This analyses of data may lead to serious spots in calculating total carried deposit. From the above mentioned reasons, we decided to take precise measurements of silt deposit concentration as well as to establish methodological spots of measurements. The results of these measurements are analyzed and presented in this paper.

  20. Sterilization and lethal gamma radiation doses on adults and eggs of Sitotroga Cerealella (OLIVIER)

    International Nuclear Information System (INIS)

    Wiendl, F.M.; Bovi, O.A.; Arthur, V.

    1975-04-01

    The influence of lethal doses of radiation from a cobalt 60 gamma source on eggs, adults and fertitility of Sitotroga Cerealella (Olivier) is described. Eggs irradiated with a dose of 14 Krad still showed viability of 16.1%. On longevity doses up to 70 Krad were usually non lethal but some variation could be observed related to the larval diet. Females fertilized by males irradiated with a dose of 70 Krad produced 36% fertile eggs. When the females were irradiated with the same dose, their fertility dropped to 2.2% and when both sexes were irradiated with a 60 Krad dose, the fertility was 28.8%

  1. Method of treatment of radioactive silts and soils

    International Nuclear Information System (INIS)

    Varlakov, A.P.; Sobolev, I.A.; Barinov, A.S.; Dmitriev, S.A.; Karlin, S.V.; Flit, V.U.

    1997-01-01

    To solve the problem of silts and soils that are contaminated with radioactive and toxic substances, the following method has been developed at SIA RADON. The material is mixed with limestone and other components, including up to 70% (mass) of dried residue of liquid radioactive waste. The mixture is heated at 800 to 1,000 C, shredded, and used to form cement. This cementation process may be used to treat radioactive or other chemical waste. The work demonstrated that in the case of silts, for example, the product volume is reduced by a factor of 1.5 to 3 compared to the initial silts volume. A fast hardening, durable product is obtained, the quality of which is not inferior to that obtained by using the traditional binders. For some parameters, e.g., hardening rate and macroelement leaching, the current method is significantly better than the traditional cementation process. It has also been demonstrated that, over a wide range of parameters, when dry residue of liquid radioactive waste is used in the initial mixture, the part of NO x can be reduced to nitrogen, thereby reducing NO x emissions

  2. Impact of tillage intensity on clay loam soil structure

    DEFF Research Database (Denmark)

    Daraghmeh, Omar; Petersen, Carsten; Munkholm, Lars Juhl

    Soil structure and structural stability are key parameters in sustainable soil management and optimum cropping practices. Locally and temporally adapted precision tillage may improve crop performance while at the same time reduce environmental impacts. The main objective of this study...... was to improve the knowledge of precision tillage practices through characterizing the effect of varied tillage intensities on structural properties of a clay loam soil. A field experiment was conducted using a randomized complete block design with two main factors, i.e. operational speed (OS, 2 levels......) and rotovating speed (RS, 3 levels). The tillage was conducted using a PTO-driven rotovator equipped to measure angular velocity. The effect of traffic compaction, made directly after tillage, was measured on soil taken from wheel track (WT) compared with soil outside wheel track (NWT). Soil samples from 0-3 cm...

  3. Processing Uranium-Bearing Materials Containing Coal and Loam

    Energy Technology Data Exchange (ETDEWEB)

    Civin, V; Prochazka, J [Research and Development Laboratory No. 3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

    1967-06-15

    Among the ores which are classified as low-grade in the CSSR are mixtures of coal and bentonitic loam of tertiary origin, containing approximately 0.1% U and with a moisture content at times well above 20-30%. The uranium is held mainly by the carbonaceous component. Conventional processing of these materials presents various difficulties which are not easily overcome. During leaching the pulp thickens and frequently becomes pasty, due to the presence of montmorillonites. Further complications arise from the high sorption capacity of the materials (again primarily due to montmorillonites) and poor sedimentation of the viscous pulps. In addition, the materials are highly refractory to the leaching agents. The paper presents experience gained in solving the problems of processing these ores. The following basic routes were explored: (1) separation of the carbonaceous and loamy components: The organic component appears to be the main activity carrier. Processing the concentrated material upon separation of the inactive or less active loam may not only remove the thixotropic behaviour but also substantially reduce the cost of the ore treatment; (2) 'liquifying' the pulps or preventing the thickening of the pulp by addition of suitable agents; (3) joint acid or carbonate processing of the materials in question with current ore types; (4) removal or suppression of thixotropic behaviour by thermal pretreatment of the material; and (5) application of the 'acid cure' method. The first method appears to be the most effective, but it presents considerable difficulties due to the extreme dispersion of the carbonaceous phase and further research is being carried out. Methods 2 and 3 proved to be unacceptable. Method 4, which includes roasting at 300-400{sup o}C, is now being operated on an industrial scale. The final method has also shown definite advantages for particular deposits of high montmorillonite content material. (author)

  4. Performance Evaluations of Three Silt Fence Practices Using a Full-Scale Testing Apparatus

    Directory of Open Access Journals (Sweden)

    R. Alan Bugg

    2017-07-01

    Full Text Available Erosion and sediment controls on construction sites minimize environmental impacts from sediment-laden stormwater runoff. Silt fence, a widely specified perimeter control practice on construction projects used to retain sediment on-site, has limited performance-based testing data. Silt fence failures and resultant sediment losses are often the result of structural failure. To better understand silt fence performance, researchers at the Auburn University-Erosion and Sediment Control Testing Facility (AU-ESCTF have evaluated three silt fence options to determine possible shortcomings using standardized full-scale testing methods. These methods subject silt fence practices to simulated, in-field conditions typically experienced on-site without the variability of field testing or the limited application of small-scale testing. Three different silt fence practices were tested to evaluate performance, which included: (1 Alabama Department of Transportation (ALDOT Trenched Silt Fence, (2 ALDOT Sliced Silt Fence, and (3 Alabama Soil and Water Conservation Committee (AL-SWCC Trenched Silt Fence. This study indicates that the structural performance of a silt fence perimeter control is the most important performance factor in retaining sediment. The sediment retention performance of these silt fence practices was 82.7%, 66.9% and 90.5%, respectively. When exposed to large impoundment conditions, both ALDOT Trench and Sliced Silt Fence practices failed structurally, while the AL-SWCC Trenched Silt Fence did not experience structural failure.

  5. Suspended silt concentrations in the lower Olifants River (Mpumalanga and the impact of silt releases from the Phalaborwa Barrage on water quality and fish survival

    Directory of Open Access Journals (Sweden)

    Y. Buermann

    1995-08-01

    Full Text Available Silt loads in the Olifants and Sabie river systems inside the Kruger National Park, were monitored by collecting water samples every consecutive week for a period of 20 months. The variation in silt concentration, changes in selected physico-chemical water quality variables and fish mortalities during flushing (i.e. release of silt, by sluicing of the Phalaborwa Barrage, were also monitored. The Olifants River inside the Kruger National Park carried high silt loads in summer; in the dry season the suspensoid load was greatly reduced. A similar pattern was observed in the Sabie River, but the silt loads were generally lower. It was apparent that silt loads released from the Phalaborwa Barrage led to large variations in the natural silt loads of the Olifants River. These increased amounts of silt (25 000 mg/1 to >70 000 mg/1 caused drastic reductions in the dissolved oxygen concentration of the water, ranging from >6 mg/1 to 0 mg/1. Depending on the severity and duration of the flushing, fish succumb to such silt loads. These findings, as well as published information, indicate that the management strategy of flushing to improve storage capacity is ecological unacceptable. It is therefore suggested that the use of the Phalaborwa Barrage as a future reservoir should be critically re-evaluated.

  6. Thermal conductivity tests on buffermasses of bentonite/silt

    International Nuclear Information System (INIS)

    Knutsson, S.

    1977-09-01

    The investigation concerns the thermal conductivity of the bentonite/quartz buffer mass suggested as embedding substance for radioactive canisters. The first part presents the theoretical relationships associated with the various heat transfer mechanisms in moist granular materials. Chapter 3 describes the author's experimental determination of the thermal conductivity of the buffer mass. The tested mass consisted of 10 percent (by weight) bentonite and 90 percent natural silt. Four tests were made with different water content values and degree of water saturation. A comparison between the measured and calculated thermal conductivities is given. It is shown that the conductivity can be calculated with an accuracy of +-20 percent. (author)

  7. Treatment of radioactive silts and soils with organic materials

    International Nuclear Information System (INIS)

    Sobolev, I.A.; Barinov, A.S.; Dmitriev, S.A.; Lifanov, F.A.; Varlakov, A.P.; Karlin, S.V.

    1997-01-01

    Moscow SIA RADON is developing the ''Clinker'' method to treat radioactive silts and grounds. The ''Clinker'' method consists of radioactive silt (ground) mixed with lime and other components. This mixture is calcined at 800 to 1000 o C. The product is ground to a surface area size of 2500 to 4500 cm 2 /g, mixed with water at a water-to-cement ratio not less than 0.25, and aged to form a solid monolith. The ''Clinker'' method was compared to the traditional cementation methods. The ''Clinker'' method reduces the final volume and enhance the strength characteristics of the final product. The ''Clinker'' cement compound has higher hardening rate. Preliminary data show that it has higher cold resistance, sulfate and leaching corrosion durability in comparison to one prepared by the traditional cementation method. The range of applicability of the ''Clinker'' method is increased by the possibility of treating materials containing up to 80% (mass) of organic materials, such as turf, flora and fauna decomposition products, and manmade material, including natural materials, such as petroleum products and polymers. In addition, the ''Clinker'' method does not require expensive waste binders, i.e., cement. The ''Clinker'' cement can be used for cementation of other radioactive waste. (author)

  8. Non-cohesive silt turbidity current flow processes; insights from proximal sandy-silt and silty-sand turbidites, Fiordland, New Zealand

    Science.gov (United States)

    Strachan, Lorna J.; Bostock, Helen C.; Barnes, Philip M.; Neil, Helen L.; Gosling, Matthew

    2016-08-01

    Silt-rich turbidites are commonly interpreted as distal marine deposits. They are associated with interlaminated clay and silt deposition from the upper and rear portions of turbidity currents. Here, multibeam bathymetry and shallow sediment core data from the intra-slope Secretary Basin, Fiordland, New Zealand, located laminar) flows that have undergone a variety of up-dip flow transformations. Most flows were initially erosive followed by deposition of partitioned 2- or 3- phase mixed mode flows that include high-density transitional and laminar flows that can be fore- or after-runners to low-density turbulent flow sections. Turbulence is inferred to have been suppressed in high-density flows by increasing flow concentration of both sands and silts. The very fine and fine sand modal grain sizes of sandy-silt and silty-sand turbidites are significantly coarser than classical abyssal plain silt turbidites and are generally coarser than overbank silt turbidites. While the low percentage of clays within Secretary Basin sandy-silt and silty-sand turbidites represents a fundamental difference between these and other silt and mud turbidites, we suggest these beds represent a previously undescribed suite of proximal continental slope deposits.

  9. Migration of cesium-137 through sandy soil layer effect of fine silt on migration

    International Nuclear Information System (INIS)

    Ohnuki, Toshihiko; Wadachi, Yoshiki

    1983-01-01

    The migration of 137 Cs through sandy soil layer was studied with consideration of the migration of fine silt by column method. It was found that a portion of fine silt migrated through the soil layer accompanying with 137 Cs. The mathematical migration model of 137 Cs involved the migration of fine silt through such soil layer was presented. This model gave a good accordance between calculated concentration distribution curve in sandy soil layer and effluent curve and observed those. So, this model seems to be advanced one for evaluating migration of 137 Cs in sandy soil layer with silt. (author)

  10. Experimental testing of a SAG digital SILT application

    International Nuclear Information System (INIS)

    Haapanen, P.; Maskuniitty, M.; Heikkinen, J.; Korhonen, J.

    1995-10-01

    A prototype dynamic testing harness for programmable automation systems has been specified and implemented at the Technical Research Centre of Finland (VTT). In order to get experience on the methodology and equipment for the testing of systems important to the safety of nuclear power plants, where the safety and reliability requirements often are very high, two different pilot systems have been tested. One system was an ABB Master application, which was loaned for testing from ABB Atom by Teollisuuden Voima Oy (TVO). Another system, loaned from Siemens AG(SAG) by IVO International Oy (IVO), was an application realized with SAG's digital SILT technology. The report describes the testing of the SAG application. The purpose of the testing was not to assess the pilot system, but to get experience in the testing methodology and find out the further development needs and potentials of the test methodology and equipment. The experience show that dynamic testing is one feasible way to get more confidence about the safety and reliability of a programmable system that would be hard to achieve by other means. It also shows that more development of the test harness is still needed, especially concerning the comparison of the obtained test response to the expected response provided by the logical model of the system. Also the user interface of the on-line part of the test harness needs development. Methods for generation of the test cases also need further development eg. for achieving statistical significance for the reliability estimates. (10 refs., 90 figs., 9 tabs.)

  11. Effects of Androctonus crassicauda (Olivier, 1807 (Scorpiones: Buthidae venom on rat metabolism

    Directory of Open Access Journals (Sweden)

    O. Ozkan

    2008-01-01

    Full Text Available Scorpions are venomous arthropods of the Arachnida class and are considered relatives of spiders, ticks and mites. There is not any study about the biochemical effects of Androctonus crassicauda (Olivier, 1807 venom. Therefore, in the present study, we aimed at evaluating the toxicity of the venom from A. crassicauda, which is responsible for a number of deaths of infants, children and adults in tropical and subtropical countries. For this purpose, rats (n=35 were divided into seven groups of five animals each; venom solutions (250µg/kg were subcutaneously injected into rats; blood samples were taken from each animal at various times; and serum biochemical parameters were measured (levels of total proteins, total bilirubin, albumin, globulin, urea, creatinine, uric acid, glucose, cholesterol, triglycerides, sodium, chlorine, potassium and calcium, and the activity of the enzymes alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase. Serum levels of glucose, cholesterol, aspartate aminotransferase, alanine aminotransferase and uric acid increased in envenomed animals, compared to controls. There was a statistically positive correlation between Na+ and Cl- ions.

  12. Interpretation of Piezocones in Silt, Using Cavity Expansion and Critical State Methods

    DEFF Research Database (Denmark)

    Bakmar, Christian LeBlanc; Randolph, M. F.

    2008-01-01

    was simulated using cylindrical cavity expansion in conjunction with a plasticity model formulated within the framework of critical state soil mechanics. The results readily explain the low cone tip resistance measured in silt sediments; this is a derived effect of the silt having a large slope of the critical...... state line, resulting in rather weak and compressible behaviour at high mean effective stresses....

  13. Identification and stabilization methods for problematic silt soils : a laboratory evaluation of modification and stabilization additives.

    Science.gov (United States)

    2003-07-01

    The instability and pumping response of non-plastic, high silt (and fine sand) soils was investigated. Common reagents, i.e., lime, lime-fly ash, Portland cement, and slag cement were included as admixtures with three high silt (and fine sand) soils....

  14. [Effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis].

    Science.gov (United States)

    Wang, Jinqui; Xu, Zhaoli; Shi, Chun; Chen, Yaqu

    2002-07-01

    The effect of suspended silt from dredging at Yangtze estuary on Brachionus plicatilis was investigated by clonal culture (to construct life table) and population accumulative culture. The intrinsic increasing rate of the rotifer population was greatly reduced under different concentrations (1, 3, 5, 7 and 9 mg.ml-1) of silt, from 29.6% to 64.1%, and to a maximum of 130.0%. The suspended silt affected population survival rate, rather than its reproduction rate. In accumulative culture, the densities of female, males, parthenogenetic eggs, and resting eggs in the population were not affected by silt. It was concluded that the presence of suspended silt should have a certain negative influence on the rotifer population in dredging Yangtze estuary.

  15. Residual efficacy of cypermethrin and pirimiphos-methyl against Sitotroga cerealella (Olivier in wheat grain

    Directory of Open Access Journals (Sweden)

    Pražić-Golić Marijana

    2017-01-01

    Full Text Available Residual efficacy of EC formulations of two insecticides: cypermethrin supplemented with the synergist piperonyl butoxide, and pirimiphos-methyl, against adults of the Angoumois grain moth, Sitotroga cerealella (Olivier, was investigated in the laboratory (at 25±1°C and 55-60% r.h. by applying water solutions of products based either on cypermethrin (1.6 mg a.i./kg of wheat grain or pirimiphos-methyl (4 mg a.i./kg of wheat grain to wheat grain. Insect mortality on deposits of different age: 0, 7, 14, 30, 60, 90, 120, 150 and 180 days was estimated after 2, 7 and 14 days of insect exposure to treated wheat. After 2 day exposure, cypermethrin caused mortality of up to 46% on all deposits (age 0-180 days. After 7 days of exposure, high efficacy (94-100% was found only on deposits that were up to 90 days old, while the mortality of S. cerealella adults on all deposits following 14 days of exposure was 98-100%, and it was probably additionally enhanced by natural mortality. Pirimiphos-methyl was 98-100% effective after 2 days of exposure to deposits that were up to 30 days old, while it achieved maximum efficacy (100% after 7 days of insect exposure to deposits aging for up to 150 days, and 94% efficacy on 180 days old deposits. After 14 days of adult exposure to all deposit ages, there were no surviving insects (efficacy 100%. The results show that pirimiphos-methyl was more effective against S. cerealella adults and had a longer residual activity than cypermethrin.

  16. Geopolymerisation of silt generated from construction and demolition waste washing plants.

    Science.gov (United States)

    Lampris, C; Lupo, R; Cheeseman, C R

    2009-01-01

    Recycling plants that size, sort and wash construction and demolition waste can produce high quality aggregate. However, they also produce up to 80ton per hour of filter cake waste containing fine (waste and normally landfilled. This research investigated the potential to form geopolymers containing silt, which would allow this problematic waste to be beneficially reused as aggregate. This would significantly improve the economic viability of recycling plants that wash wastes. Silt filter cakes have been collected from a number of aggregate washing plants operating in the UK. These were found to contain similar aluminosilicate crystalline phases. Geopolymer samples were produced using silt and silt mixed with either metakaolin or pulverised fuel ash (PFA). Silt geopolymers cured at room temperature had average 7-day compressive strengths of 18.7MPa, while partial substitution of silt by metakaolin or PFA increased average compressive strengths to 30.5 and 21.9MPa, respectively. Curing specimens for 24h at 105 degrees C resulted in a compressive strength of 39.7MPa and microstructural analysis confirmed the formation of dense materials. These strengths are in excess of those required for materials to be used as aggregate, particularly in unbound applications. The implications of this research for the management of waste silt at construction and demolition waste washing plants are discussed.

  17. Hamlet no cinema: as adaptações fílmicas de Laurence Olivier (1948 e Franco Zeffirelli (1990

    Directory of Open Access Journals (Sweden)

    Rogério Tomaz

    2011-10-01

    Full Text Available As inter-relações entre as artes traduzem-se numa discussão bastante recente. Um dos elementos que compõem esse quadro é a tradução intersemiótica que consiste na relação entre sistemas signícos. Este artigo propõe a análise da abordagem intersemiótica na adaptação da peça de teatro Hamlet, Príncipe da Dinamarca, de William Shakespeare para o cinema nos filmes de Laurence Olivier e Franco Zeffirelli.

  18. influence of tillage practices on physical properties of a sandy loam

    African Journals Online (AJOL)

    DR. AMINU

    many regions of the world if the mechanics of tillage effects on soil physical properties is to be well understood. Thus, the ... tillage systems on water storage of a sandy loam soil after 22 years of ..... Soil infiltration ... and processes. Academy ...

  19. Assessment of structural stability of a degraded sandy clay loam soil ...

    African Journals Online (AJOL)

    The effects of bare, two legumes and four grasses cover treatments on the structural stability of a sandy clay loam Ultisol were studied within a two year period. The experiment was of a randomised complete block design with seven treatments. The legume treatments were Centrosema pubescens (Ce) and Pueraria ...

  20. Pore structure characteristics after two years biochar application to a sandy loam field

    DEFF Research Database (Denmark)

    Sun, Zhencai; Arthur, Emmanuel; de Jonge, Lis Wollesen

    2015-01-01

    the effects of birch wood biochar (20, 40, and 100 Mg ha−1) applied to a sandy loam on soil total porosity and pore structure indices. Bulk and intact soil samples were collected for physicochemical analyses and water retention and gas diffusivity measurements between pF 1.0 and pF 3.0. Biochar application...

  1. Investigating the settling dynamics of cohesive silt particles with particle-resolving simulations

    Science.gov (United States)

    Sun, Rui; Xiao, Heng; Sun, Honglei

    2018-01-01

    The settling of cohesive sediment is ubiquitous in aquatic environments, and the study of the settling process is important for both engineering and environmental reasons. In the settling process, the silt particles show behaviors that are different from non-cohesive particles due to the influence of inter-particle cohesive force. For instance, the flocs formed in the settling process of cohesive silt can loosen the packing, and thus the structural densities of cohesive silt beds are much smaller than that of non-cohesive sand beds. While there is a consensus that cohesive behaviors depend on the characteristics of sediment particles (e.g., Bond number, particle size distribution), little is known about the exact influence of these characteristics on the cohesive behaviors. In addition, since the cohesive behaviors of the silt are caused by the inter-particle cohesive forces, the motions of and the contacts among silt particles should be resolved to study these cohesive behaviors in the settling process. However, studies of the cohesive behaviors of silt particles in the settling process based on particle-resolving approach are still lacking. In the present work, three-dimensional settling process is investigated numerically by using CFD-DEM (Computational Fluid Dynamics-Discrete Element Method). The inter-particle collision force, the van der Waals force, and the fluid-particle interaction forces are considered. The numerical model is used to simulate the hindered settling process of silt based on the experimental setup in the literature. The results obtained in the simulations, including the structural densities of the beds, the characteristic lines, and the particle terminal velocity, are in good agreement with the experimental observations in the literature. To the authors' knowledge, this is the first time that the influences of non-dimensional Bond number and particle polydispersity on the structural densities of silt beds have been investigated separately

  2. Investigation on the cohesive silt/clay-particle sediment via the coupled CFD-DEM simulations

    Science.gov (United States)

    Xu, S.; Sun, H.; Sun, R.

    2017-12-01

    Sedimentation of silt/clay particles happens ubiquitously in nature and engineering field. There have been abundant studies focusing on the settling velocity of the cohesive particles, while studies on the sediment deposited from silt/clay irregular particles, including the vertical concentration profile of sediment and the various forces among the deposited particles are still lacking. This paper aims to investigate the above topics by employing the CFD-DEM (Computational Fluid Dynamics-Discrete Element Method) simulations. In this work, we simulate the settling of the mono- and poly- dispersed silt/clay particles and mainly study the characteristics of the deposited cohesive sediment. We use the bonded particles to simulate the irregular silt/clay aggregates at the initial state and utilize the van der Waals force for all micro-particles to consider the cohesive force among silt/clay particles. The interparticle collision force and the fluid-particle interaction forces are also considered in our numerical model. The value of the mean structural density of cohesive sediment obtained from simulations is in good agreement with the previous research, and it is obviously smaller than no-cohesive sediment because of the existence of the silt/clay flocs. Moreover, the solid concentration of sediment increases with the growth of the depth. It is because the silt/clay flocs are more easily to break up due to the gradually increased submerged gravity of the deposited particles along the depth. We also obtain the noncontacted cohesive force and contact force profiles during the sedimentation and the self-weight consolidation process. The study of the concentration profile and the forces among silt/clay sediment will help to give an accurate initial condition for calculating the speed of the reconsolidation process by employing the artificial loads, which is necessary for practical designs of the land reclamation projects.

  3. Researches on the Constitutive Models of Artificial Frozen Silt in Underground Engineering

    Directory of Open Access Journals (Sweden)

    Yugui Yang

    2014-01-01

    Full Text Available The researches on the mechanical characteristic and constitutive models of frozen soil have important meanings in structural design of deep frozen soil wall. In the present study, the triaxial compression and creep tests have been carried out, and the mechanical characteristic of frozen silt is obtained. The experiment results show that the deformation characteristic of frozen silt is related to confining pressure under conventional triaxial compression condition. The frozen silt presents strain softening in shear process; with increase of confining pressure, the strain softening characteristic gradually decreases. The creep curves of frozen silt present the decaying and the stable creep stages under low stress level; however, under high stress level, once the strain increases to a critical value, the creep strain velocity gradually increases and the specimen quickly happens to destroy. To reproduce the deformation behavior, the disturbed state elastoplastic and new creep constitutive models of frozen silt are developed. The comparisons between experimental results and calculated results from constitutive models show that the proposed constitutive models could describe the conventional triaxial compression and creep deformation behaviors of frozen silt.

  4. TRANSLATING THE NEW WORLD(S: A SEMIOTIC APPROACH TO PARROT AND OLIVIER IN AMERICA BY PETER CAREY

    Directory of Open Access Journals (Sweden)

    Luigi Gussago

    2012-12-01

    Full Text Available In his latest novel Parrot and Olivier in America (2009 the Australian-born novelist Peter Carey explores the way three seemingly incompatible civilisations translate the New World. On the one hand Olivier, the snobbish French aristocrat, struggles to understand the concept of democracy in America because he wants to translate it ‘literally’ into his own system (of behaviour, social convenience, pragmatics, etc.. On the other hand, Parrot, the British-Australian pícaro and Olivier’s “clown and secretaire”, enjoys rewriting his master’s awful calligraphy, changing some of the Frenchman’s views on America according to his whim, and deliberately acting as a bad translator. Thirdly, the American free citizen, the “Man of the Future” (p. 187: s/he uses language creatively, coining a personal idiolect as evidence of belonging to a nation at its début, where “greed might tear the land apart but still the low could climb so high” (p. 251. This paper aims at illustrating how these three entities translate other systems of values, or their loss of values, into systems with which they can identify. The theoretical framework of my study proceeds from the contributions of Yuri Lotman, the main representative of the Tartu-Moscow school of semiotics.

  5. Una especie nueva de Tillus Olivier, 1790 (Coleoptera, Cleridae de la Península Ibérica

    Directory of Open Access Journals (Sweden)

    López-Colón, José Ignacio

    2003-06-01

    Full Text Available Tillus ibericus sp. nov. is described from the Comunidad Autónoma de Madrid (Spain and it is compared to the western Palaearctic species of the genus Tillus Olivier, 1790. Tillus ibericus is easily distinguished from all other species of the genus by the structure of the elytral sculpture and its characteristic coloration. This new species shares a general habitus and characters from the antennae, and general body stucture with T. flabellicornis Fairmaire, 1866, a species from northern Africa. All preexisting records of T. flabellicornis in the Iberian Peninsula correspond to T. ibericus sp. nov..Se describe Tillus ibericus sp. nov. de la Comunidad Autónoma de Madrid (España y se compara con las otras especies del género Tillus Olivier, 1790 de la región Paleártica occidental. Tillus ibericus se distingue con facilidad de las especies próximas por la estructura del punteado elitral y por su coloración característica. La especie nueva comparte un aspecto general y caracteres de la estructura del cuerpo y de las antenas con T. flabellicornis Fairmaire, 1866 del Norte de África. Todas las citas anteriores de T. flabellicornis de la Península Ibérica corresponden a T. ibericus sp. nov.

  6. Determination of Selenium Toxicity for Survival and Reproduction of Enchytraeid Worms in a Sandy Loam Soil

    Science.gov (United States)

    2016-07-01

    LOAM SOIL ECBC-TR-1388 Roman G. Kuperman Ronald T. Checkai Michael Simini Carlton T. Phillips RESEARCH AND TECHNOLOGY DIRECTORATE Richard M...plastic wrap was stretched over the top of each container and secured with a rubber band. Three pinholes were made in the plastic wrap to 6...172–178. Glover, J.; Levander, O.; Parizek, J.; Vouk, V. Selenium. In Handbook on the Toxicology of Metals; Friberg, L., Norberg, G.F., Vouk, V.B

  7. Qualidade de fruto da aceroleira cv. Olivier em dois estádios de maturação

    Directory of Open Access Journals (Sweden)

    Elisa Adriano

    2011-10-01

    Full Text Available A acerola é um fruto de grande potencial econômico e nutricional devido ao seu alto teor de vitamina C, destacando-se como alimento funcional. É comercializada principalmente na forma de polpa congelada e fruto in natura. O objetivo deste estudo foi avaliar a qualidade dos frutos da aceroleira cv. Olivier em dois estádios de maturação. Para tanto, foram colhidas amostras de frutos em um pomar comercial no município de Junqueirópolis-SP. Foram realizadas a determinação da cor externa dos frutos e análises das características químicas de teor de sólidos solúveis, pH, acidez titulável, açúcares redutores, 'ratio' e ácido ascórbico de frutos semi-maduros e maduros. Os resultados obtidos permitiram concluir que os frutos semimaduros apresentaram maior acidez total, menor teor de sólidos solúveis e menor concentração de açúcares; no entanto, estes frutos apresentaram maiores teores de vitamina C, expressa em ácido ascórbico. Portanto, quando se buscam altos índices de vitamina C, os frutos devem ser colhidos num estádio de maturação menos avançado, com coloração alaranjada. O estudo demonstrou também que a cv Olivier produz frutos com características adequadas tanto para o mercado in natura quanto para a indústria, apresentando boa coloração e características químicas dentro dos padrões para esta fruta.

  8. Turnover of intra- and extra-aggregate organic matter at the silt-size scale

    Science.gov (United States)

    I. Virto; C. Moni; C. Swanston; C. Chenu

    2010-01-01

    Temperate silty soils are especially sensitive to organic matter losses associated to some agricultural management systems. Long-term preservation of organic C in these soils has been demonstrated to occur mainly in the silt- and clay-size fractions, although our knowledge about the mechanisms through which it happens remains unclear. Although organic matter in such...

  9. Studies for determining drain solid flow in bed silt, using radioisotope techniques

    International Nuclear Information System (INIS)

    Sanchez, W.

    1976-01-01

    A process for measuring solid flow in silt bed using isotopic technique is studied. Comparative studies for initial movement of grinded glass grains and sand grains is done. The development for determining the minimum mass of radioative grains of sand, used for flow evaluation is also studied. Further experiments in the field of reference confirm technological conditions for the method [pt

  10. Fault creep and stress drops in saturated silt-clay gouge

    International Nuclear Information System (INIS)

    Bombolakis, E.G.; Hepburn, J.C.; Roy, D.C.

    1978-01-01

    An analysis of physicochemical processes in saturated silt-clay gouge indicates that this type of fault zone material can account for for the following phenomena: (1) the nonlinear mechanical behavior indicated by certain geophysical measurements along the San Andreas fault zone, (2) the low stress drops associated with earthquakes to several kilometers' depth, and (3) the recurrence of creep-induced instabilities at shallow depths along fault zones. A rheological model is described for a gouge consisting of colloidal size clay platelets with absorbed water, brittle silt size particles, and 'free' pore water. Recurrence of shallow earthquakes or accelerated creep is explained in the model by thixotropic hardening of the colloidal phase following shear deformation, i.e., by electrochemical reorientation of clay platelets from a dispersed structure to a face-to-edge type of structure during a quiescent period. The silt phase must support part of the effective mean stress for thixotropic hardening to occur at several kilometers' depth. The peak shear strength of the gouge in this case is expressed in functional form by S/sub p/=f[kappaP/sub e/+sigma-bar/sub c/ tan psi/sub e/; sigma-bar/sub s/ tan psi/sub s/], where kappa, P/sub e/, and psi/sub e/ are Hvorslev parameters; sigma-bar/sub c/ is the effective stress in the colloidal phase, acting normal to the shear zone; sigma-bar/sub s/ is the effective stress in the silt phase, acting normal to the shear zone; and psi/sub s/ is the 'friction angle' of the silt phase. The peak shear strength is time dependent owing to viscous type contacts between absorbed water layers surrounding the colloidal platelets. The time-dependent nature of S/sub p/ may be responsible for certain nonlinear behavior noted in fault zones and for the small stress drops associated with earthquakes occurring at several kilometers' depth

  11. Interaction of the Bored Sand and Gravel Drain Pile with the Surrounding Compacted Loam Soil and Foundation Raft Taking into Account Rheological Properties of the Loam Soil and Non-Linear Properties of the Drain Pile

    Science.gov (United States)

    Ter-Martirosyan, Z. G.; Ter-Martirosyan, A. Z.; Anzhelo, G. O.; Buslov, A. S.

    2018-01-01

    The task of the interaction of the sand and gravel drain pile with the surrounding loam soil after its preliminary deep compaction and formation of the composite ground cylinder from the drain pile and surrounding compacted loam soil (cells) is considered in the article. It is seen that the subsidence and carrying capacity of such cell considerably depends on physical and mechanical properties of the compacted drain piles and surrounding loam soil as well as their diameter and intercellular distance. The strain-stress state of the cell is considered not taking into account its component elements, but taking into account linear and elastic-plastic properties of the drain pile and creep flow of the surrounding loam soil. It is stated that depending on these properties the distribution and redistribution of the load on a cell takes place from the foundation raft between the drain pile and surrounding soil. Based on the results of task solving the formulas and charts are given demonstrating the ratio of the load between the drain pile and surrounding loam soil in time.

  12. Mineralogia, química e estabilidade de agregados do tamanho de silte de solos da Região Sudeste do Brasil Mineralogy, chemistry and stability of silt-size aggregates of soils from the Southeast Region of Brazil

    Directory of Open Access Journals (Sweden)

    Antonio Carlos Tadeu Vitorino

    2003-01-01

    Full Text Available Com o objetivo de avaliar a relação da composição mineralógica e química do solo com a estabilidade de agregados do tamanho de silte, foram realizados estudos utilizando-se amostras de horizontes A e B de diversos solos da Região Sudeste do Brasil. Amostras de TFSA foram dispersas a 12.000 rpm por 20 minutos e a fração silte foi separada por esgotamento da fração argila, constituindo-se na fração denominada pseudo-silte, a qual foi sonificada, separando-se a fração argila desagregada (por sifonamento da fração silte propriamente dita. Estudos de correlação mostraram que as composições mineralógica e química dos solos têm efeito marcante na dispersão de argila, com reflexos na fração silte. Maiores teores de gibbsita refletem em maior estabilidade dos agregados do tamanho de silte ao passo que a caulinita proporciona efeito inverso. As formas de Al determinadas na fração pseudo-silte estão associadas à maior dificuldade de dispersão da fração argila dos solos.The objective of this work was to evaluate the relationship of soil mineralogical and chemical composition with stability of silt-size aggregates. The studies were carried out using samples of A and B horizons of some soils from the Southeast Region of Brazil. Fine-earth samples were dispersed at 12,000 rpm during 20 minutes and the silt fraction was separated through clay fraction drain, constituting the fraction named pseudo-silt, which was sonificated, separating the desegregated clay fraction (by sonication from the properly named silt fraction. Correlation analyses showed that the soil mineralogical and chemical compositions have marked influence upon clay dispersion, with reflections on the silt fraction. Higher amounts of gibbsite reflect in higher stability of silt-size aggregates, while the kaolinite promotes inverse effect. The Al forms determined on the pseudo-silt fraction are associated with higher difficult of dispersion of clay fraction of

  13. Effet structurant de la plante hôte chez la bruche de l'arachide, Caryedon serratus (Olivier, 1790 (Coleoptera : Bruchidae

    Directory of Open Access Journals (Sweden)

    Sembène, M.

    2012-01-01

    Full Text Available Structuring effect of the host plant in the groundnut bruchid, Caryedon serratus (Olivier, 1790 (Coleoptera: Bruchidae. Twenty-six samples of the groundnut seed-beetle which were reared from pods of five different host plants (Arachis hypogaea L., Bauhinia rufescens Lam., Cassia sieberiana DC., Piliostigma reticulatum (DC. Hochst. and Tamarindus indica L. in four localities of Senegal were compared using electrophoresis based on six loci of four enzymatic systems. The population structure of Caryedon serratus Olivier was analysed using Weir and Cockerham's estimator of Wright's F-statistics. θ value (0.235 and the dendrogram of Rogers'genetic distances revealed a high degree of genetic differentiation between host plants. Genetic analysis without C. sieberiana samples indicated that populations form host races which are partially isolated according to their host plants (θ = 0.035. Geographical distances between localities are not decisive for genetic structuration of C. serratus populations from a given host plant.

  14. Cadmium phytoextraction from loam soil in tropical southern China by Sorghum bicolor.

    Science.gov (United States)

    Wang, Xu; Chen, Can; Wang, Jianlong

    2017-06-03

    The cadmium (Cd) uptake characteristics by Sorghum bicolor cv. Nengsi 2# and Cowley from the acidic sandy loam soil (pH = 6.1) during the entire growth period (100 days) were investigated in pot outdoors in a tropical district of southern China, Hainan Island. The Cd-spiked levels in soil were set as 3 and 15 mg/kg. Correspondingly, the available Cd levels in soil extracted by Mehlich III solution were 2.71 and 9.41 mg/kg, respectively. Basically, two varieties in a full growth period (100 days) did not show a significant difference in their growth and Cd uptake. Under high Cd stress, the plant growth was inhibited and its biomass weight and height decreased by 38.7-51.5% and 27.6-28.5%, respectively. However, S. bicolor showed higher bioaccumulation capability of Cd from soil to plant [bioconcentration factor (BCF)>4], and higher transfer capability of Cd from roots to shoots [translocation factor (TF)>1] under high Cd stress; Cd contents in the roots, stems, and leaves of S. bicolor reached 43.79-46.07, 63.28-70.60, and 63.10-66.06 mg/kg, respectively. S. bicolor exhibited the potential phytoextraction capability for low or moderate Cd-contamination in acidic sandy loam soil.

  15. Effect of size and concentration of silt particles on erosion of Pelton turbine buckets

    Energy Technology Data Exchange (ETDEWEB)

    Padhy, M.K.; Saini, R.P. [Alternate Hydro Energy Centre, Indian Institute of Technology Roorkee, Roorkee (India)

    2009-10-15

    Erosive wear of hydro turbine runners depends upon different parameters such as size, hardness and concentration of silt particles, velocity of flow, properties of the base material of the turbine components and operating hours of the turbine. Various researchers have conducted experiments to study the effect of these parameters on erosive wear. Most of these experiments were on small-size samples at different types of test rigs to simulate the flow conditions in turbines, however actual flow conditions and the phenomenon of erosive wear are too complex to simulate. Under the present study, effect of these parameters on erosion in actual conditions has been investigated experimentally. An extensive experimental study has been carried out on a small scale Pelton turbine. Based on the experimental data collected for different parameters, correlations have been developed for wear rate of Pelton turbine buckets as a function of critical parameters, i.e., size and concentration of silt particles and jet velocity. (author)

  16. IMPACT OF A USED STABILISER ON THE CALIFORNIA BEARING RATIO OF THE CLAYEY-SANDY SILT

    Directory of Open Access Journals (Sweden)

    Katarzyna Kamińska

    2017-01-01

    Full Text Available The paper aimed at the determination of the California Bearing Ratio of a stabilised and unstabilised fine-grained mineral soil. A clayey-sandy silt with the addition of 3, 6 and 10% of road stabilisers Solidex and Solidex A was used for the tests. The tests were carried out in the press Tritech 50 at the loading of 22 and 44 N. The stabilised samples were subjected to 7-days treatment, whereas unstabilised 4-days treatment. Stabilization with the applied road binders brought positive effects, there occurred a significant improvement in the mechanical properties of the clayey-sandy silt. The better binder, which significantly increased the value of the CBR ratio, was Solidex A. The use of hydraulic binders is of a great importance in road building, because their addition improves the mechanical properties of weaker mineral soils.

  17. The Gut Entomotype of Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Dryophthoridae and Their Effect on Host Nutrition Metabolism

    Directory of Open Access Journals (Sweden)

    Abrar Muhammad

    2017-11-01

    Full Text Available For invasive insects, the potential roles of gut microbiota in exploiting new food resources and spreading remain elusive. Red palm weevil (RPW, Rhynchophorus ferrugineus Olivier, is an invasive destructive pest which feeds on nutrient-poor tender tissues and has caused extensive mortality of palm trees. The microbes associated with insects can improve their nutrition assimilation. However, experimental evidence on the interactions between RPW and its gut microbiota is still absent. The aim of this study is to determine the dynamics changes and the bacterial entomotype in the RPW gut and its potential physiological roles. Here, we confirmed RPW harbors a complex gut microbiota mainly constituted by bacteria in the families Enterobacteriaceae, Lactobacillaceae, Entomoplasmataceae, and Streptococcaceae. RPW gut microbiota exhibited a highly stable microbial community with low variance in abundance across different life stages and host plants. Furthermore, the abundance of Enterobacteriaceae was markedly increased but that of Acetobacteraceae was reduced significantly after administration of antibiotics. Although no significant effects were found on the body weight gain of RPW larvae, these alterations dramatically decreased the concentration of hemolymph protein and glucose while that of hemolymph triglyceride increased. In the gut of wild-caught RPW larvae, seven bacterial species in the genera Klebsiella, Serratia, Enterobacter, and Citrobacter were shown to have an ability to degrade cellulose. Together, RPW accommodate a stable gut microbiota which can degrade plant polysaccharides and confer their host optimal adaptation to its environment by modulating its metabolism.

  18. Parasitoids associated with the black scale Saissetia oleae(Olivier (Hemiptera: Coccidae in olive trees in Minas Gerais State, Brazil

    Directory of Open Access Journals (Sweden)

    Ernesto Prado

    2015-10-01

    Full Text Available Black scale, Saissetia oleae (Olivier (Hemiptera: Coccidae is an important pest of olive trees (Olea europaea L. that requires the use insecticides for its control. Parasitoids are important regulating agents of this pest, but currently, no information on its complex of natural enemies and their impact on black scale in Brazilian conditions exists. This study focused on identifying parasitoid wasps that were associated with the black scale on olive trees to establish their relative abundance and rate of parasitism. Samplings were maintained in an olive orchard located in Maria da Fe, south of the state of Minas Gerais, Brazil, and infested branches were stored in emergence containers to recover parasitoids. Another group was kept in Flanders batteries to evaluate the rate of parasitism in approximately 100 scales. Sixteen parasitoid species were collected during the sampling period, and the most common species were Coccophagus caridei (Brèthes (Hymenoptera: Aphelinidae, Diversinervus elegans Silvestri (Hymenoptera: Encyrtidae, and Mesopeltita truncatipennis (Waterston (Hymenoptera: Pteromalidae, the latter of which was most abundant and frequent. Parasitism ranged from 3 to 31% with peaks in summer and autumn. This level could be considered insufficient to hold the black scale under the economic injury level; however, these parasitoids should be preserved for contributions to population regulation.

  19. EXPERIMENTAL DETERMINATION OF VARIABILITY IN PERMEABILITY OF SANDY SILT SOIL MIXED WITH FLY ASH IN PROPORTIONATE

    OpenAIRE

    Rasna Sharma*, Dr. M.K. Trivedi

    2016-01-01

    This paper presents the experimental determination of variability in permeability of sandy silt soil by blending with fly ash. The grain size, porosity, structure of the soil, specific gravity of the soil, viscosity and temperature are important factors in varying the permeability of the soil. Permeability is the flow conduction property of the soil. The void ratio with in the soil plays a vital role in varying the permeability. By blending with finer grains like fly ash in the soil with sand...

  20. IMPACT OF SAND DREDGING AND SILT EXTRACTION ACTIVITY ON RIVER AND ITS CHARACTERISTICS : A REVIEW

    OpenAIRE

    Vishal S. Gholap

    2016-01-01

    The present research work highlights the influences of sand dredging and extensive silt quarrying activity on rivers. The sand dredging activity and its impact on the river processes and other river environment have discussed in the present review paper. It has seen that most of the rivers and their processes are highly degraded and altered due to these activities. In India and almost in the regions of Maharashtra, the ground water is decreasing and such activities also invited the problems ...

  1. Carbon saturation in the silt and clay particles in soils with contrasting mineralogy

    Directory of Open Access Journals (Sweden)

    Francisco Matus

    2016-07-01

    Full Text Available The silt and clay particles play a key role as stabilizing agents of soil organic carbon (SOC. Several lines of evidence indicate a theoretical maximum or C saturation in individual particles. In the present study, we hypothesized that a C fraction displaying linear accumulation relative to the SOC is not influenced by C saturation, while a fraction displaying an asymptotic relationship is regarded as saturated (Stewart et al., 2008. The aim of the present study was to compare the amount of C in the silt and clay sized fractions in temperate and subtropical cropping soils across a range of textures with different mineralogy. Twenty-one and 18 soil samples containing 1:1 and 2:1 clay of temperate soil from Chile under monoculture of maize (Zea maiz L. for at least 30 years and 9 subtropical soils from Mexico under maize and bean (Phaseolus vulgaris L. cropping for 9 years having mixed clay were collected at 0-0.1 m. The SOC of 2:1 soils was significantly higher (14±0.5 g kg-1 dry soil than 1:1 soils (10±0.7 g kg-1. However, subtropical soils showed the highest values (59±0.5 g kg-1. A positive (P < 0.01 relationship was observed between the SOC and the C in the silt fraction (R2 0.80-0.97, P < 0.01. In contrast, the clay fraction remained constant or showed asymptotic behavior. We conclude that the silt fraction, unlike clay, showed no evidence of C saturation, while clay accumulates C to a maximum. On average, the 2:1 clay was saturated at 1-2 g C kg-1 and 1:1 at 1 g C kg-1, and subtropical soils at 14 g C kg-1.

  2. Frequency distribution of ABO and Rh (D) blood group alleles in Silte Zone, Ethiopia

    OpenAIRE

    Kassahun Tesfaye; Yohannes Petros; Mebeaselassie Andargie

    2015-01-01

    Background: Frequency distribution of blood groups is important as it is used in modern medicine, genetic research, anthropology, and tracing ancestral relations of humans. The ABO and Rh blood groups are the most important blood groups despite the long list of several other blood groups discovered so far. Aim of the study: To study and document the frequency of ABO and Rh (D) blood groups in three ethnic groups of Silte Zone, Ethiopia. Subjects and methods: ABO and Rh (D) typing was ca...

  3. [Monitoring of water and salt transport in silt and sandy soil during the leaching process].

    Science.gov (United States)

    Fu, Teng-Fei; Jia, Yong-Gang; Guo, Lei; Liu, Xiao-Lei

    2012-11-01

    Water and salt transport in soil and its mechanism is the key point of the saline soil research. The dynamic rule of water and transport in soil during the leaching process is the theoretical basis of formation, flush, drainage and improvement of saline soil. In this study, a vertical infiltration experiment was conducted to monitor the variation in the resistivity of silt and sandy soil during the leaching process by the self-designed automatic monitoring device. The experimental results showed that the peaks in the resistivity of the two soils went down and faded away in the course of leaching. It took about 30 minutes for sandy soil to reach the water-salt balance, whereas the silt took about 70 minutes. With the increasing leaching times, the desalination depth remained basically the same, being 35 cm for sandy soil and 10 cm for the silt from the top to bottom of soil column. Therefore, 3 and 7 leaching processes were required respectively for the complete desalination of the soil column. The temporal and spatial resolution of this monitoring device can be adjusted according to the practical demand. This device can not only achieve the remote, in situ and dynamic monitoring data of water and salt transport, but also provide an effective method in monitoring, assessment and early warning of salinization.

  4. Effect of biochar on aerobic processes, enzyme activity, and crop yields in two sandy loam soils

    DEFF Research Database (Denmark)

    Sun, Zhencai; Bruun, Esben; Arthur, Emmanuel

    2014-01-01

    Biochar added to agricultural soils may sequester carbon and improve physico-chemical conditions for crop growth, due to effects such as increased water and nutrient retention in the root zone. The effects of biochar on soil microbiological properties are less certain. We addressed the effects...... of wood-based biochar on soil respiration, water contents, potential ammonia oxidation (PAO), arylsulfatase activity (ASA), and crop yields at two temperate sandy loam soils under realistic field conditions. In situ soil respiration, PAO, and ASA were not significantly different in quadruplicate field...... plots with or without biochar (20 Mg ha−1); however, in the same plots, volumetric water contents increased by 7.5 % due to biochar (P = 0.007). Crop yields (oat) were not significantly different in the first year after biochar application, but in the second year, total yields of spring barley increased...

  5. A Visual Basic program to classify sediments based on gravel-sand-silt-clay ratios

    Science.gov (United States)

    Poppe, L.J.; Eliason, A.H.; Hastings, M.E.

    2003-01-01

    Nomenclature describing size distributions is important to geologists because grain size is the most basic attribute of sediments. Traditionally, geologists have divided sediments into four size fractions that include gravel, sand, silt, and clay, and classified these sediments based on ratios of the various proportions of the fractions. Definitions of these fractions have long been standardized to the grade scale described by Wentworth (1922), and two main classification schemes have been adopted to describe the approximate relationship between the size fractions.Specifically, according to the Wentworth grade scale gravel-sized particles have a nominal diameter of ⩾2.0 mm; sand-sized particles have nominal diameters from <2.0 mm to ⩾62.5 μm; silt-sized particles have nominal diameters from <62.5 to ⩾4.0 μm; and clay is <4.0 μm. As for sediment classification, most sedimentologists use one of the systems described either by Shepard (1954) or Folk (1954, 1974). The original scheme devised by Shepard (1954) utilized a single ternary diagram with sand, silt, and clay in the corners to graphically show the relative proportions among these three grades within a sample. This scheme, however, does not allow for sediments with significant amounts of gravel. Therefore, Shepard's classification scheme (Fig. 1) was subsequently modified by the addition of a second ternary diagram to account for the gravel fraction (Schlee, 1973). The system devised by Folk (1954, 1974) is also based on two triangular diagrams (Fig. 2), but it has 23 major categories, and uses the term mud (defined as silt plus clay). The patterns within the triangles of both systems differ, as does the emphasis placed on gravel. For example, in the system described by Shepard, gravelly sediments have more than 10% gravel; in Folk's system, slightly gravelly sediments have as little as 0.01% gravel. Folk's classification scheme stresses gravel because its concentration is a function of

  6. Neutron Gauge Calibration Curve as Affected by Chloride Concentration and Bulk Density of Loam Soil

    International Nuclear Information System (INIS)

    AL-Hasani, A.A.; Fahad, A.A.; Shihab, R.M.

    2010-01-01

    chloride concentration and bulk density are considered among important factors affecting calibration curve of neutron gauge in the soil.The aim of this study was to investigate the effect of chloride concentration and bulk density of a loam soil on neutron gauge calibration curve.Sufficient amount of loam soil was air dried screened through a 2 mm sieve,and divided into three equal portions.Sodium chloride of 2.5 and 6.6g kg'-1 soil was added to the first and second portions,respectively.The third portion was left as a control.The soil then moistened and mixed well to make volumetric water content within the range of 0.01 to 0.24 cm 3 cm - 3. The moist soil was packed into an iron drum 0.80 m diameter and 1.00 m height to obtain bulk densities of 1.10 and 1.30 to 1.60 Mg m - 3 for uncompacted soil,respectively.Access tube 0.05 m inner diameter was installed in the center of the drum.Three readings from CPN 503 neutron gauge were taken at each 0.15,0.30, 0.45,and 0.75 m depth.Results indicated that the count (counts/standard count) for an aqueous solution decreased with the increase in chloride concentration.Similarly, the slope of the linear calibration curves of the investigated soil decreased with the increase in chloride concentration.Shifting of the curves was 9 to 10%for the uncompacted soil, whereas it was 12 to 14 % for the compacted of low and high concentration of chloride, respectively . Results of changing bulk density always reduced the slope value as compared with the uncorrected count ratio.

  7. Improvement in the water retention characteristics of sandy loam soil using a newly synthesized poly(acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite material.

    Science.gov (United States)

    Shahid, Shaukat Ali; Qidwai, Ansar Ahmad; Anwar, Farooq; Ullah, Inam; Rashid, Umer

    2012-08-03

    The use of some novel and efficient crop nutrient-based superabsorbent hydrogel nanocomposites (SHNCs), is currently becoming increasingly important to improve the crop yield and productivity, due to their water retention properties. In the present study a poly(Acrylamide-co-acrylic acid)/AlZnFe2O4 superabsorbent hydrogel nanocomposite was synthesized and its physical properties characterized using Energy Dispersive X-ray (EDX), FE-SEM and FTIR spectroscopic techniques. The effects of different levels of SHNC were studied to evaluate the moisture retention properties of sandy loam soil (sand 59%, silt 21%, clay 19%, pH 7.4, EC 1.92 dS/m). The soil amendment with 0.1, 0.2, 0.3 and 0.4 w/w% of SHNC enhanced the moisture retention significantly at field capacity compared to the untreated soil. Besides, in a separate experiment, seed germination and seedling growth of wheat was found to be notably improved with the application of SHNC. A delay in wilting of seedlings by 5-8 days was observed for SHNC-amended soil, thereby improving wheat plant growth and establishment.

  8. Post-cyclic behavior of low plasticity silt under full and limited liquefaction using triaxial compression testing.

    Science.gov (United States)

    2010-02-01

    During an earthquake, liquefaction does not happen all the time. It depends on the duration and magnitude of the earthquake and the properties (with relationship to resistance of liquefaction) of the low plasticity silt. Under low duration or magnitu...

  9. Effects of anthropogenic silt on aquatic macroinvertebrates and abiotic variables in streams in the Brazilian Amazon

    Energy Technology Data Exchange (ETDEWEB)

    Couceiro, Sheyla Regina Marques; Hamada, Neusa [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Forsberg, Bruce Rider [Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Entomologia, Manaus, AM (Brazil); Inst. Nacional de Pesquisas da Amazonia, Coordenacao de Pesquisas em Ecologia, Manaus, AM (Brazil); Padovesi-Fonseca, Claudia [Univ. de Brasilia, Dept. de Ecologia, Brasilia, DF (Brazil)

    2010-01-15

    Purpose: While environmental risks associated with petroleum extraction such as oil spills or leaks are relatively well known, little attention has been given to the impacts of silt. The increase in petroleum exploitation in Amazonia has resulted in sediment input to aquatic systems, with impacts on their biodiversity. Here we use a combination of field measurements and statistical analyses to evaluate the impacts of anthropogenic silt derived from the construction of roads, borrow pits, and wells during the terrestrial development of gas and oil, on macroinvertebrate communities in streams of the Urucu Petroleum Province in the Central Brazilian Amazon. Material and methods: Ten impacted and nine non-impacted streams were sampled in January, April, and November of 2007. Macroinvertebrates were sampled along a 100-m continuous reach in each stream at 10-m intervals using a dip net. Abiotic variables including, a siltation index (SI), suspended inorganic sediment (SIS), sediment color index (SCI), suspend organic sediment (SOS), pH, electrical conductivity, dissolved oxygen, temperature, water velocity, channel width, and depth, were measured at three equidistant points in each stream ({proportional_to}30-m intervals). Results and discussion: SI did not differ between impacted and undisturbed streams. SIS was higher and SCI lower (more reddish) in impacted than in non-impacted streams. SCI had a positive and SIS a negative effect on both macroinvertebrate richness and density. SIS and SCI also influenced macrophyte taxonomic composition. In impacted streams, taxonomic richness and density were 1.5 times lower than in non-impacted streams. No taxon was significantly associated with impacted streams. SIS was positively correlated with SOS and electrical conductivity while SCI was negatively correlated with SOS, electrical conductivity, and pH. The lack of difference in SI between impacted and nonimpacted streams suggests that anthropogenic sediment does not accumulate

  10. Development of a radioisotope based silt density gauge for industrial applications

    International Nuclear Information System (INIS)

    Mitra, Anant; Walinjkar, P.B.; Kumar, Umesh; Dash, Ashutosh

    2015-01-01

    Silt density gauge (SDG) is a conventional equipment to gauge the specific gravity or fraction of solids in slurries, oils, food products and process fluids flowing through a pipe. SDG can also be used for measuring density of sediment during dredging operations in Ports. The gauge consists of three major components i.e. radiation source, detector and control unit. The developed prototype of SDG has been tested in a laboratory experimental setup for density measurement of slurry and its performance was evaluated. (author)

  11. Degradation and persistence of cotton pesticides in sandy loam soils from Punjab, Pakistan.

    Science.gov (United States)

    Tariq, Muhammad Ilyas; Afzal, Shahzad; Hussain, Ishtiaq

    2006-02-01

    The present study evaluated the influence of temperature, moisture, and microbial activity on the degradation and persistence of commonly used cotton pesticides, i.e., carbosulfan, carbofuran, lambda-cyhalothrin, endosulfan, and monocrotophos, with the help of laboratory incubation and lysimeter studies on sandy loam soil (Typic Ustocurepts) in Pakistan. Drainage from the lysimeters was sampled on days 49, 52, 59, 73, 100, 113, and 119 against the pesticide application on days 37, 63, 82, 108, and 137 after the sowing of cotton. Carbofuran, monocrotophos, and nitrate were detected in the drainage samples, with an average value, respectively, of 2.34, 2.6 microg/L, and 15.6 mg/L for no-tillage and 2.16, 2.3 microg/L, and 13.4 mg/L for tillage. In the laboratory, pesticide disappearance kinetics were measured with sterile and nonsterile soils from 0 to 10 cm in depth at 15, 25, and 35 degrees C and 50% and 90% field water capacities. Monocrotophos and carbosulfan dissipation followed first-order kinetics while others followed second-order kinetics. The results of incubation studies showed that temperature and moisture contents significantly reduced the t(1/2) (half-life) values of pesticides in sterile and nonsterile soil, but the effect of microbial activity was nearly significant that might be due to less organic carbon (0.3%). The presence of carbofuran and monocrotophos in the soil profile (0-10, 10-30, 30-60, 60-90, 90-150 cm) and the higher concentrations of endosulfan and lambda-cyhalothrin in the top layer (0-10 cm) showed the persistence of the pesticides. The detection of endosulfan and lambda-cyhalothrin in the 10-30 cm soil layer might be due to preferential flow. The data generated from this study could be helpful for risk assessment studies of pesticides and for validating pesticide transport models for sandy loam soils in cotton-growing areas of Pakistan.

  12. Prediction of strain energy-based liquefaction resistance of sand-silt mixtures: An evolutionary approach

    Science.gov (United States)

    Baziar, Mohammad H.; Jafarian, Yaser; Shahnazari, Habib; Movahed, Vahid; Amin Tutunchian, Mohammad

    2011-11-01

    Liquefaction is a catastrophic type of ground failure, which usually occurs in loose saturated soil deposits under earthquake excitations. A new predictive model is presented in this study to estimate the amount of strain energy density, which is required for the liquefaction triggering of sand-silt mixtures. A wide-ranging database containing the results of cyclic tests on sand-silt mixtures was first gathered from previously published studies. Input variables of the model were chosen from the available understandings evolved from the previous studies on the strain energy-based liquefaction potential assessment. In order to avoid overtraining, two sets of validation data were employed and a particular monitoring was made on the behavior of the evolved models. Results of a comprehensive parametric study on the proposed model are in accord with the previously published experimental observations. Accordingly, the amount of strain energy required for liquefaction onset increases with increase in initial effective overburden pressure, relative density, and mean grain size. The effect of nonplastic fines on strain energy-based liquefaction resistance shows a more complicated behavior. Accordingly, liquefaction resistance increases with increase in fines up to about 10-15% and then starts to decline for a higher increase in fines content. Further verifications of the model were carried out using the valuable results of some downhole array data as well as centrifuge model tests. These verifications confirm that the proposed model, which was derived from laboratory data, can be successfully utilized under field conditions.

  13. Preliminary Assessment of Silting and The Quality of Bottom Sediments in A Small Water Reservoir

    Directory of Open Access Journals (Sweden)

    Bąk Łukasz

    2014-07-01

    Full Text Available The aim of this study was to assess the degree of silting and pollution of bottom sediments in a small water reservoir Lubianka situated in Starachowice, Świętokrzyskie Province, with selected heavy metals (Pb, Cr, Cd, Cu, Ni, Zn, Fe, Mn, Hg. Catchment basin of the reservoir is forested in 92%. Other parts are covered by estates of detached houses, barren lands and green areas. Bathymetric measurements and analyses of trace elements in bottom sediments were made in 2012. After 28 years of exploitation, reservoir's basin accumulated 43 thousand cubic metres of sediments i.e. 4.7% of its initial volume. Mean annual silting rate was 0.17%. Due to the content of copper and chromium, bottom sediments were classified to the II category (sediments of average pollution according to geochemical standards. Concentrations of Pb, Cd and Hg in all analysed samples were below geochemical background. In a sample collected at the inlet to the reservoir, the TEL index for chromium was exceeded by 25.6%. In other samples the threshold values of the TEL and PEL indices were not exceeded.

  14. Assessment of Silt Density Index (SDI) as Fouling Propensity Parameter in Reverse Osmosis Desalination

    KAUST Repository

    Rachman, Rinaldi

    2011-07-01

    Reverse osmosis operations are facing persistent fouling phenomenon that has challenged the integrity of these processes. Prediction of fouling potential by measuring a fouling index toward feed water is essential to ensure robust operation. Moreover, employing a reliable fouling index with good reproducibility and precision is necessary. Silt density index (SDI) is considered insufficient in terms of reliability and empirical theory, among other limitations. Nevertheless due its simplicity, SDI measurement is utilized extensively in RO desalination systems. The aim of this research is to assess the reliability of SDI. Methods include the investigation of different SDI membranes and study of the nature of the SDI filtration. Results demonstrate the existence of the membrane properties\\' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role on SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity assisted SDI measurements along with determination of UF pretreated and clean water fouling potential, establishes the indication of non-fouling related phenomena involved on SDI measurement such as a natural organic matter adsorption and hydrodynamic condition that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI value. Keywords: Reverse Osmosis, Fouling index, Particulate Fouling, Silt Density Index (SDI), and Assessment of SDI.

  15. ELASTOPLASTICIDAD DE UN SUELO FRANCO ARENOSO DE SABANA I SANDY LOAM SAVANNA SOIL ELASTOPLASTICITY

    Directory of Open Access Journals (Sweden)

    Américo Hossne García

    2018-04-01

    Full Text Available The knowledge of elastoplastic properties is important for calculating soil elastic and plastic deformations experienced by static or dynamic loads generated, for example, by farm implements and root growth. The objective of this study was to determine the soil elastoplastic parameters: Young’s modulus (E, the shear modulus (G, bulk modulus (K and Poisson’s ratio (υ of a sandy-loam soil from a savanna in Monagas State, Venezuela. Triaxial tests and regression analyses were used to interpret the variance between them. The results show that E varied from 4693.39 to 36669.35 kPa; G from 700 to 5000 kPa; K from 500 to 2000 kPa and υ had a value of 0.50. It is concluded that these soils are incompressible under plastic conditions, i.e. easily deformable. The Poisson’s ratio varied significantly with soil water content. The Young modulus, bulk modulus and the shear modulus showed high variation with respect to water content. Both the Young’s modulus and Poisson’s ratio increased, at low soil water content, with the rise in chamber pressure .

  16. The Influence Of Loam Type And Cement Content On The Compressive Strength Of Rammed Earth

    Directory of Open Access Journals (Sweden)

    Narloch P. L.

    2015-03-01

    Full Text Available Currently, a worldwide dynamic rise of interest in using soil as a construction material can be observed. This trend is evident in the rapid rise of the amount of standards that deal with soil techniques. In 2012 the number of standards was larger by one third than five years prior. To create a full standardization of the rammed earth technique it is necessary to take into account the diversity of used soil and stabilizing additives. The proportion of the components, the process of element production and the research methods must also be made uniform. The article describes the results of research on the compressive strength of rammed earth samples that differed from each other with regards to the type of loam used for the mixture and the amount of the stabilizer. The stabilizer used was Portland cement CEM I 42.5R. The research and the analysis of the results were based on foreign publications, the New Zealand standard NZS 4298:1998, the American Standard NMAC14.7.4 and archival Polish Standards from the 1960’s that dealt with earth material.

  17. Effect of biochar amendment on nitrate retention in a silty clay loam soil

    Directory of Open Access Journals (Sweden)

    Angela Libutti

    2016-08-01

    Full Text Available Biochar incorporation into agricultural soils has been proposed as a strategy to decrease nutrient leaching. The present study was designed to assess the effect of biochar on nitrate retention in a silty clay loam soil. Biochar obtained from the pyrogasification of fir wood chips was applied to soil and tested in a range of laboratory sorption experiments. Four soil treatments were considered: soil only (control, soil with 2, 4 and 8% of biochar by mass. The Freundlich sorption isotherm model was used to fit the adsorbed amount of nitrate in the soil-biochar mixtures. The model performed very well in interpreting the experimental data according to a general linear regression (analysis of co-variance statistical approach. Nitrate retention in the soilbiochar mixtures was always higher than control, regardless the NO3 – concentration in the range of 0-400 mg L–1. Different sorption capacities and intensities were detected depending on the biochar application rate. The highest adsorption capacity was observed in the soils added with 2 and 4% of biochar, respectively. From the results obtained is possible to infer that nitrate retention is higher at lower biochar addition rate to soil (2 and 4% and at lower nitrate concentration in the soil water solution. These preliminary laboratory results suggest that biochar addition to a typical Mediterranean agricultural soil could be an effective management option to mitigate nitrate leaching.

  18. Depth distribution of preferential flow patterns in a sandy loam soil as affected by tillage

    Directory of Open Access Journals (Sweden)

    C. T. Petersen

    1997-01-01

    Full Text Available Dye-tracer studies using the anionic dye Brilliant Blue FCF were conducted on a structured sandy loam soil (Typic Agrudalf. 25 mm of dye solution was applied to the surface of 11 1.6 x 1.6 m field plots, some of which had been subjected to conventional seed bed preparation (harrowing while others had been rotovated to either 5 or 15 cm depth before sowing. The soil was excavated to about 160 cm depth one or two days after dye application. Flow patterns and structural features appearing on vertical or horizontal cross sections were examined and photographed. The flow patterns were digitized, and depth functions for the number of activated flow pathways and the degree of dye coverage were calculated. Dye was found below 100 cm depth on 26 out of 33 vertical cross sections made in conventionally tilled plots showing that preferential flow was a prevailing phenomenon. The depth-averaged number of stained flow pathways in the 25-100 cm layer was significantly smaller in a plot rotovated to 5 cm depth than in a conventionally tilled plot, both under relatively dry initial soil conditions and when the entire soil profiles were initially at field capacity. There were no examples of dye penetration below 25 cm depth one month after deep rotovation. Distinct horizontal structures in flow patterns appearing at 20-40 cm depth coupled with changes in flow domains indicated soil layering with abrupt changes in soil structure and hydraulic properties.

  19. Inhibition effect of zinc in wastewater on the N2O emission from coastal loam soils.

    Science.gov (United States)

    Huang, Yan; Ou, Danyun; Chen, Shunyang; Chen, Bin; Liu, Wenhua; Bai, Renao; Chen, Guangcheng

    2017-03-15

    The effects of zinc (Zn) on nitrous oxide (N 2 O) fluxes from coastal loam soil and the abundances of soil nitrifier and denitrifier were studied in a tidal microcosm receiving livestock wastewater with different Zn levels. Soil N 2 O emission significantly increased due to discharge of wastewater rich in ammonia (NH 4 + -N) while the continuous measurements of gas flux showed a durative reduction in N 2 O flux by high Zn input (40mgL -1 ) during the low tide period. Soil inorganic nitrogen concentrations increased at the end of the experiment and even more soil NH 4 + -N was measured in the high-Zn-level treatment, indicating an inhibition of ammonia oxidation by Zn input. Quantitative PCR of soil amoA, narG and nirK genes encoding ammonia monooxygenase, nitrate reductase and nitrite reductase, respectively, showed that the microbial abundances involved in these metabolisms were neither affected by wastewater discharge nor Zn contamination. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Eleven years' effect of conservation practices for temperate sandy loams: II. Soil pore characteristics

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Munkholm, Lars Juhl

    2017-01-01

    Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore characte......Conservation agriculture (CA) is regarded by many as a sustainable intensification strategy. Minimal soil disturbance in combination with residue retention are important CA components. This study examined the long-term effects of crop rotation, residue retention, and tillage on soil pore...... characteristics of two Danish sandy loams. Rotation R2 is a rotation of winter crops (mainly cereals) with residues retained, rotation R3 a mix of winter and spring crops (mainly cereals) with residues removed, and rotation R4 the same mix of winter and spring crops, but with residues retained. Each rotation...... included the tillage treatments: moldboard plowing to 20-cm depth (MP), harrowing to 8- to 10-cm depth (H) and direct drilling (D). Soil cores were taken from the topsoil (4–8, 12–16, 18–27 cm) in mid-autumn 2013 and early spring 2014. Water retention, air permeability, and gas diffusivity was determined...

  1. Critical undrained shear strength of sand-silt mixtures under monotonic loading

    Directory of Open Access Journals (Sweden)

    Mohamed Bensoula

    2014-07-01

    Full Text Available This study uses experimental triaxial tests with monotonic loading to develop empirical relationships to estimate undrained critical shear strength. The effect of the fines content on undrained shear strength is analyzed for different density states. The parametric analysis indicates that, based on the soil void ratio and fine content properties, the undrained critical shear strength first increases and then decreases as the proportion of fines increases, which demonstrates the influence of fine content on a soil’s vulnerability to liquefaction. A series of monotonic undrained triaxial tests were performed on reconstituted saturated sand-silt mixtures. Beyond 30% fines content, a fraction of the silt participates in the soil’s skeleton chain force. In this context, the concept of the equivalent intergranular void ratio may be an appropriate parameter to express the critical shear strength of the studied soil. This parameter is able to control the undrained shear strength of non-plastic silt and sand mixtures with different densities.   Resumen Este estudio utiliza evaluaciones experimentales triaxiales con cargas repetitivas para desarrollar relaciones empíricas y estimar la tensión crítica de corte bajo condiciones no drenadas. El efecto de contenido de finos en la tensión de corte sin drenar se analizó en diferentes estados de densidad. El análisis paramétrico indica que, basado en la porosidad del suelo y las propiedades del material de finos, la tensión de corte sin drenar primero se incrementa y luego decrece mientras la proporción de finos aumenta, lo que demuestra la influencia de contenido de finos en la vulnerabilidad del suelo a la licuación. Una serie de las evaluaciones se realizó en  mezclas rehidratadas y saturadas de arena y cieno. Más allá del 30 % de los contenidos finos, una fracción del cieno hace parte principal de la cadena de fuerza del suelo. En este contexto, el concepto de porosidad equivalente

  2. Sur l'olivier

    Directory of Open Access Journals (Sweden)

    Mohammed Khadda

    2015-10-01

    Full Text Available *** Mohammed Khadda (Mostaganem, le 14 mars 1930 – Alger, le 4 mai 1991. Autodidacte, « peintre du Signe », sculpteur, graveur et théoricien de l'art. Employé, dès 1944, dans l'imprimerie de « L'Aïn Sefra » où il réalisait, entre autres, des maquettes. En 1947, il s'inscrit à un cours de dessin par correspondance et réalise ses premières aquarelles. Ainsi commence la grande aventure de l'expression plastique qui mène Mohammed Khadda de Mostaganem à Alger (où, au Musée des Beaux Arts, il rega...

  3. Water and solute transport in agricultural soils predicted by volumetric clay and silt contents

    DEFF Research Database (Denmark)

    Karup, Dan; Møldrup, Per; Paradelo Pérez, Marcos

    2016-01-01

    tracer mass could be well fitted to an analytical solution to the classical convection-dispersion equation. Both cumulative tracer mass and concentration as a function of time were hereby reasonable well predicted from the simple inputs of bulk density, clay and silt contents, and applied tracer mass......Solute transport through the soil matrix is heterogeneous and greatly affected by soil texture, soil structure, and macropore networks. This study examined the relationship between tracer breakthrough characteristics, soil hydraulic properties, and basic soil properties. Hundred...... of the soil structure rather than the actual formation of macropores causing preferential flow. The arrival times of 5 % and up to 50 % of the tracer mass were found to be strongly correlated with volumetric fines content. The hereby predicted tracer concentration breakthrough points up to 50% of applied...

  4. Lagoon Sediment Dynamics: A Coupled Model to Study a Medium-Term Silting of Tidal Channels

    Directory of Open Access Journals (Sweden)

    Marco Petti

    2018-04-01

    Full Text Available The silting of tidal channels is a natural process that affects several shallow lagoons and makes it difficult to navigate, requiring regular maintenance interventions. This phenomenon is the result of the complex non-linear interaction between tidal currents and wave motion. In this work, the morphodynamic evolution of the Marano and Grado lagoon is investigated by means of a two-dimensional horizontal (2DH morphological-hydrodynamic and a spectral coupled model. An innovative procedure to reproduce the overall bathymetric changes in the medium term and, in particular, the volumes deposited inside channels, is presented. An average year with a sequence of winds and tides acting over that time was reconstructed, carrying out cross correlation techniques and spectral analyses of measured data. The predicted morphological evolution matches the annual dredged volumes in the lagoon critical branches and shows the distribution of erosion and deposition of cohesive sediments according to spatially variable values of critical shear stress.

  5. Phosphorus application to cotton enhances growth, yield, and quality characteristics on a sandy loam soil

    International Nuclear Information System (INIS)

    Ahmad, M.; Ranjha, A.M.

    2009-01-01

    Phosphorus (P) is the second most limiting nutrient in cotton (Gossypium hirsutum L.) production after nitrogen. Under wheat-cotton cropping system of Pakistan most of the farmers apply P fertilizer only to wheat crop. A field experiment was conducted to evaluate the effect of fertilizer P on the growth, yield and fibre quality of cotton on a sandy loam calcareous soil at farmer's field in cotton growing area of district Khanewal, Punjab. Five levels of P (0, 17, 26, 34 and 43 kg P ha /sup -1/) along with 120 kg N and 53 kg K ha/sup -1/ were applied. The response of cotton growth parameters was greater than quality components to P addition in calcareous soil. There was significant increase in the growth and yield parameters with each additional rate of P. The response of number of bolls per plant, boll weight and seed cotton yield was to the tune of 88.23, 16.82 and 42%, respectively at P application rate of 34 kg ha/sup -1/. Cotton quality components (lint %age, fiber length and fiber strength) improved from 2 to 5% where 43 kg P ha/sup -1/ was added. The lint and seed P concentration was little affected by P application as compared to stem and leaves showing its essentiality for cell division and development of meristematic tissue. Phosphorus use, thus not only valuable for wheat crop but also its application to cotton crop is of vital importance in improving both lint yield and quality. (author)

  6. Surface Runoff of Pesticides from a Clay Loam Field in Sweden.

    Science.gov (United States)

    Larsbo, Mats; Sandin, Maria; Jarvis, Nick; Etana, Ararso; Kreuger, Jenny

    2016-07-01

    Pesticides stored at or close to the soil surface after field application can be mobilized and transported off the field when surface runoff occurs. The objective of our study was to quantify the potential pesticide losses in surface runoff from a conventionally managed agricultural field in a Swedish climate. This was achieved by measuring surface runoff volumes and concentrations in runoff of six spring-applied pesticides and autumn-applied glyphosate and its metabolite aminomethylphosphonic acid (AMPA). Measurements were performed for 3 yr both during the growing seasons and during intervening winter snowmelt periods on a clay loam field close to Uppsala. During growing seasons, surface runoff was generated on only five occasions during one 25-d period in 2012 when the infiltration capacity of the soil may have been reduced by structural degradation due to large cumulative rainfall amounts after harrowing. Concentrations in surface runoff exceeded Swedish water quality standards in all samples during this growing season for diflufenican and pirimicarb. Surface runoff was generated during three snowmelt periods during the winter of 2012-2013. All of the applied pesticides were found in snowmelt samples despite incorporation of residues by autumn plowing, degradation, and leaching into the soil profile during the period between spraying and sampling. Concentrations of glyphosate ranged from 0.12 to 7.4 μg L, and concentrations of AMPA ranged from 0 to 2.7 μg L. Our results indicate that temporal changes in hydraulic properties during the growing season and when the soil freezes during winter affect pesticide losses through surface runoff. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Plant uptake and soil retention of phthalic acid applied to Norfolk sandy loam

    International Nuclear Information System (INIS)

    Dorney, J.R.; Weber, J.B.; Overcash, M.R.; Strek, H.J.

    1985-01-01

    Plant uptake and soil retention of 14 C carboxyl-labeled phthalic acid were studied at application rates of 0.6, 6.0, 60.0, and 600.0 ppm (soil dry weight) to Norfolk sandy loam (Typic Paleudult, fine loamy, kaolinitic, thermic). Height and dry weight of corn (Zea mays L. Pioneer 3368A) (21 day), tall fescue (Festuca arundinacea Schreb. Kentucky 31) (45 day) immature soybean (Glycine max (L.) Merr. Altoona) (21 day) plant, mature soybean plant, and mature wheat (Triticum aestivum L. Butte) straw were not affected by phthalic acid applied to soil. In addition, soybean seed and wheat seed dry weight were unaffected. Immature wheat (40 day) height decreased at the 600 ppm rate. Plant uptake of phthalic acid ranged from 0 to 23 ppm and was significantly above background for all plants and plant materials except soybean pods. Fescue and immature plants exhibited the highest concentration of phthalic acid while mature wheat plants and wheat seeds exhibited the least. Most of the phthalic acid volatilized or was decomposed from the soil by the end of the study; an average of only 5.7% of the originally applied chemical was recovered in both soil or plants. An average of 0.02% of the originally applied phthalic acid leached out of the treated zone. Considering the low toxicity of phthalic acid and its relatively rapid disappearance from soil, it is unlikely to become a health hazard from contaminated plants. However, plant uptake of other toxic organics could potentially become a hazard on soils treated with sludge containing significant quantities of these substances

  8. Aggregate-associated carbon and nitrogen in reclaimed sandy loam soils

    Energy Technology Data Exchange (ETDEWEB)

    Wick, A.F.; Stahl, P.D.; Ingram, L.J. [Virginia Polytechnic Institute & State University, Blacksburg, VA (United States)

    2009-11-15

    Minimal research has been conducted on aggregate, C, and N in coarse-textured soils used to reclaim surface coal mine lands. Furthermore, little is known about the contribution different plant communities make to the recovery of aggregation in these soils. Two chronosequences of semiarid reclaimed sites with sandy loam soils were sampled under shrub- and grass-dominated communities. Aggregation, aggregate fractions, and associated C and N were measured. No definitive trends of increasing macroaggregates between sites were observed undershrubs; however, macro- and microaggregation was greater in the 16-yr-old (0.20 and 0.23 kg aggregate kg{sup -1} soil, respectively) than in the 5-yr-old soils (0.02 and 0.08 kg aggregate kg{sup -1} soil, respectively) under grasses. Although C and N concentrations were drastically reduced (50-75%) with mining activity between the <1-yr-old and native soils, aggregate C and N concentrations tinder shrubs and grasses were similar to each other and to the native soils in the 5-yr-old site. Sods under grass in the 16-yr-old site had lower available and aggregate-occluded C and N concentrations than the 5-yr-old site, while C and N concentrations did not change between 5- and 16-yr-old soils under shrubs. Conversely, aggregate C and N pool sizes under shrubs and grasses both increased with site age to conditions similar to those observed in the native soil. Reclaimed shrub site soils had consistently higher C concentrations in the older reclaimed sites (10 and 16 yr old) than the soils under grasses, indicating greater accumulation and retention of C and N in organic material under shrub than grass communities in semiarid reclaimed sites.

  9. IMPACT OF THE REPEATED TRACTOR PASSES ON SOME PHYSICAL PROPERTIES OF SILTY LOAM SOIL

    Directory of Open Access Journals (Sweden)

    Dubravko Filipović

    2011-12-01

    Full Text Available The aim of this paper was to quantify soil compaction induced by tractor traffic on untilled wet silty loam soil (Mollic Fluvisol. Changes in penetration resistance, bulk density and total porosity were measured for detecting the soil compaction. Treatments include ten passes of a four-wheel drive tractor with the engine power of 54.0 kW and weight of 3560 kg (1580 kg on the front axle and 1980 kg on the rear axle, 2.41 m distance between axles. The tyres on the tractor were cross-ply, front 11.2-24 and rear 16.9-30, with the inflation pressure of 160 kPa and 100 kPa, respectively. The speed of tractor during passes over experimental plots was 5.0 km h-1. In comparison to control, each tractor pass induced an increase in soil penetration resistance at all depths, and the average increment ratios, determined as the average of all layers, were 9.8, 18.5 and 26.1% after one, five and ten passes, respectively. The bulk density also increased with number of tractor passes, but with less percentage increasing. The increment ratios comparison to the control were 3.6, 9.5 and 12.9% after one, five and ten passes, respectively. The total porosity decreased with the number of passes, and the decrement ratios were 4.5, 16.5 and 20.8% after one, five and ten passes, respectively.

  10. Ação inseticida do extrato de Derris amazonica Killip para Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae Insecticide action of the extract of Derris amazonica Killip for Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae

    Directory of Open Access Journals (Sweden)

    Márcio Rodrigo Alecio

    2010-12-01

    Full Text Available A abundância e o potencial inseticida de Derris amazonica e a necessidade de controle de Cerotoma arcuatus Olivier (Coleoptera: Chrysomelidae na cultura do feijão-caupi (Vigna unguiculata L. Walp estimularam a realização desta pesquisa, que objetivou avaliar a ação inseticida do extrato de D. amazonica a adultos de C. arcuatus em condições de laboratório. Os bioensaios testaram as vias de intoxicação por ingestão de folhas contaminadas, contato com superfície contaminada e aplicação tópica, com delineamento experimental inteiramente casualizado, com quatro repetições. Os valores de mortalidade e consumo foliar dos insetos foram submetidos à análise de regressão, sendo utilizada a análise de Probit para determinação das CL50, da DL50 e dos TL50. O extrato de D. amazonica, contendo 3,7% de rotenona, foi tóxico para adultos de C. arcuatus via ingestão de folhas contaminadas (CL50=15,14 µL do extrato.mL-1 de água, superfície contaminada (CL50=0,45 µL do extrato.cm-2 e aplicação tópica (DL50=1,44 µL do extrato.g-1 do inseto. Mortalidades de adultos de C. arcuatus superiores a 80% e os menores tempos letais médios foram obtidos na concentração de 5% (v v-1 do extrato em todos os bioensaios. O consumo foliar de adultos de C. arcuatus foi inversamente proporcional a concentração do extrato quando expostos por via de ingestão foliar ou aplicação tópica, sendo inclusive observada inibição da alimentação dos indivíduos. O extrato de D. amazonica é tóxico para C. arcuatus e inibe a alimentação dos insetos a partir da concentração de 1% (v v-1.The abundance and insecticidal potential of Derris amazonica in addition to need of controlling Cerotoma arcuatus for bean crop stimulated this research. The objective of this work was to evaluate insecticide action of the extract of D. amazonica to adults of C. arcuatus in laboratory conditions. The bioassays were carried out using three distend methodologies: leaf

  11. Determination of p-y Curves for Bucket Foundations in Silt and Sand Using Finite Element Modelling

    DEFF Research Database (Denmark)

    Vethanayagam, Vinojan; Ibsen, Lars Bo

    slender than the tested piles. The suction bucket has a slenderness ratio of 0.5-1, thus its response is a rigid movement, where slender piles undergoes a flexible movement. Due to the importance of precise estimations, p-y formulations for suction buckets in drained and undrained silt are sought...... developed with use of finite element. In general the developed p-y formulations for the drained and undrained silt are fairly precise. Furthermore, the same method and basic formulation of the drained silt is applied to data of the drained sand from Østergaard et al. [2015]. The developed formulation...... herefore shows to be more versatile and precise than the formulation suggested by Østergaard et al. [2015]. The developed p-y formulations are functions of the effective vertical in-situ stress, soil stiffness, diameter of the bucket and the internal friction angle/the undrained shear strength....

  12. Respirable dust and quartz exposure from three South African farms with sandy, sandy loam, and clay soils.

    Science.gov (United States)

    Swanepoel, Andrew J; Kromhout, Hans; Jinnah, Zubair A; Portengen, Lützen; Renton, Kevin; Gardiner, Kerry; Rees, David

    2011-07-01

    To quantify personal time-weighted average respirable dust and quartz exposure on a sandy, a sandy loam, and a clay soil farm in the Free State and North West provinces of South Africa and to ascertain whether soil type is a determinant of exposure to respirable quartz. Three farms, located in the Free State and North West provinces of South Africa, had their soil type confirmed as sandy, sandy loam, and clay; and, from these, a total of 298 respirable dust and respirable quartz measurements were collected between July 2006-November 2009 during periods of major farming operations. Values below the limit of detection (LOD) (22 μg · m(-3)) were estimated using multiple 'imputation'. Non-parametric tests were used to compare quartz exposure from the three different soil types. Exposure to respirable quartz occurred on all three farms with the highest individual concentration measured on the sandy soil farm (626 μg · m(-3)). Fifty-seven, 59, and 81% of the measurements on the sandy soil, sandy loam soil, and clay soil farm, respectively, exceeded the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value (TLV) of 25 μg · m(-3). Twelve and 13% of respirable quartz concentrations exceeded 100 μg · m(-3) on the sandy soil and sandy loam soil farms, respectively, but none exceeded this level on the clay soil farm. The proportions of measurements >100 μg · m(-3) were not significantly different between the sandy and sandy loam soil farms ('prop.test'; P = 0.65), but both were significantly larger than for the clay soil farm ('prop.test'; P = 0.0001). The percentage of quartz in respirable dust was determined for all three farms using measurements > the limit of detection. Percentages ranged from 0.5 to 94.4% with no significant difference in the median quartz percentages across the three farms (Kruskal-Wallis test; P = 0.91). This study demonstrates that there is significant potential for over-exposure to respirable quartz in

  13. Composition Characteristics of Olivier Messiaen’s Later Orchestral Works%梅西安晚期管弦乐作品的创作特征

    Institute of Scientific and Technical Information of China (English)

    汪胜付

    2016-01-01

    Olivier Messiaen (1908~1992 ) was a great French composer of the 20th century. This paper discussed his later orchestral works composed after the 1970s, which were rarely analyzed or studied in China. Main composition characteristics of Messiaen’s last six orchestral works were analyzed and summarized as follows. First-ly, in the aspect of structure thinking, his works used multi-materials, multi-color juxtaposition and symmetry. Secondly, his composition was more extensively influ-enced by synaesthesia. Thirdly, symphonic characteristics of birdsongs were fully demonstrated in his last six orchestral works. Finally, just like his other works, these six works were deeply influenced by religion or relevant themes.%文章选取了国内20世纪法国作曲家奥利维耶·梅西安(Olivier Messiaen,1908~1992)在70年代以后创作的晚期管弦乐作品为研究对象,归纳总结了梅西安晚期的六部管弦乐作品的在创作上的主要特点与整体特征。首先,在结构思维上主要体现出多材料、多色彩并置与对称性。其次,在音乐创作上受到了更宽泛的“联觉”影响。再次,晚期六部管弦乐作品充分表现出鸟歌的交响性。最后,这六部管弦乐作品深远地受到宗教题材影响。

  14. Geotechnical characteristics of bentonite/sandy silt mixes for use in waste disposal sites

    International Nuclear Information System (INIS)

    Abeele, W.V.

    1984-06-01

    The coefficient of consolidation for bentonite/sandy silt ratios of 0.04 to 0.14 decreases inversely proportional with the square of that ratio, whereas the compression index, the swelling index, and the permeability change index increase with increasing bentonite ratio. A strong relationship also exists between the void ratio and the logarithm of the applied stress for any given bentonite ratio. The empirical linear relationship between the void ratio and the logarithm of the applied stress, developed by Taylor, is excellent and enables us to limit the evaluation of conductivity at any void ratio to the measurement of the initial and the desired void ratio, the initial conductivity, and the permeability change index. This allows us to read directly, for a given bentonite ratio, the void ratio (or compaction) needed so that a required hydraulic conductivity will prevail. This is crucial in the choice of materials or mixes to be used in a wick system where an established differentiation in hydraulic conductivity is desirable

  15. Assessment of silt density index (SDI) as fouling propensity parameter in reverse osmosis (RO) desalination systems

    KAUST Repository

    Rachman, Rinaldi; Ghaffour, NorEddine; Wali, F.; Amy, Gary L.

    2013-01-01

    Due to its simplicity, silt density index (SDI) is extensively used in reverse osmosis systems despite its limitations in predicting membrane fouling. Employing a reliable fouling index with good reproducibility and precision is necessary. The aim of this investigation is to assess the reliability of SDI in order to understand the reasons for the low level of precision and accuracy. Different commercial SDI membranes and feed water quality were used in this study. Results showed the existence of membrane properties' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role in SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity-assisted SDI measurements along with determination of ultrafiltration permeate and clean water fouling potential, establish the indication of nonfouling-related phenomena involved on SDI measurement such as natural organic matter adsorption and hydrodynamic conditions that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI values. © 2013 Desalination Publications.

  16. Gas detection in sands of high silt-clay content in the Cook Inlet area

    International Nuclear Information System (INIS)

    Bettis, F.

    1976-01-01

    When a sand contains a large amount of silt and clay it is often difficult to detect zones that contain gas using only the Archie Saturation Relationship. However, gas may be detected in these shaly formations using certain quick-look techniques. Log examples of these are presented in this paper. The first quick-look technique is an overlay of the neutron log on a density log. The neutron log is shifted relative to the density log to make the two porosity curves track in shaly water sands. Gas-bearing intervals become readily apparent from separations of the two curves where the density porosity is reading higher than the shifted neutron porosity. The second is an overlay of a neutron log on the sonic interval-transit-time log. The sonic log is shifted so as to match the neutron log in average tight sands in the section. This method has proved to be more optimistic than the density-neutron overlay above. It will find the gas-bearing zones, but may result in testing a zone or two which is nonproductive. The third method, used when no neutron log has been run, is a crossplot of the difference, sonic porosity minus density porosity, versus gamma ray API units. This is the most unreliable of the three methods because of the difficulty of determining the end points and the slope of the line on the plot which separates the gas zones from the non-gas zones

  17. Assessment of silt density index (SDI) as fouling propensity parameter in reverse osmosis (RO) desalination systems

    KAUST Repository

    Rachman, Rinaldi

    2013-01-01

    Due to its simplicity, silt density index (SDI) is extensively used in reverse osmosis systems despite its limitations in predicting membrane fouling. Employing a reliable fouling index with good reproducibility and precision is necessary. The aim of this investigation is to assess the reliability of SDI in order to understand the reasons for the low level of precision and accuracy. Different commercial SDI membranes and feed water quality were used in this study. Results showed the existence of membrane properties\\' variation within manufacturers, which then causes a lack of accuracy in fouling risk estimation. The nature of particles during SDI filtration provides information that particle concentration and size play a significant role in SDI quantification with substantial representation given by particles with size close to membrane nominal pore size. Moreover, turbidity-assisted SDI measurements along with determination of ultrafiltration permeate and clean water fouling potential, establish the indication of nonfouling-related phenomena involved on SDI measurement such as natural organic matter adsorption and hydrodynamic conditions that alters during filtration. Additionally, it was found that the latter affects the sensitivity of SDI by being represented by some portions of SDI values. © 2013 Desalination Publications.

  18. The ecological half-life of 137Cs in undisturbed silt soil

    International Nuclear Information System (INIS)

    Drosg, M.

    2012-01-01

    The time necessary to safely cultivate agricultural areas after they have been contaminated by radioactivity (e.g. after the Chernobyl accident) is not determined by the physical half-life of the radioactive isotopes in question but by their (usually much shorter) ecological half-life (). This half-life not only depends on the type of soil but also on whether the soil was fertilized or not. Therefore it is not possible to determine an ecological half-life that is universally valid. However, the value for undisturbed, unfertilized soil should provide a general indication for the duration of ecological half-life. In a silt soil in Vienna, Austria, the ecological half-life of 137 Cs was determined to be 0.8 years, which is much shorter than the physical half-life of 30 years. - Highlights: ► Absolute measurements of 137 Cs radioactivity in leaves of perennial plants. ► The natural 40 K radioactivity served as reference. ► The ecological half-life of 137 Cs in loamy soil was determined.

  19. A study on the characteristics of silt loading on paved roads in the Seoul metropolitan area using a mobile monitoring system.

    Science.gov (United States)

    Han, Sehyun; Jung, Yong-Won

    2012-07-01

    This study is considered the first attempt to apply a mobile monitoring system to estimating silt loading on paved roads in a megacity such as the Seoul metropolitan area. Using a mobile monitoring system developed in 2005, we estimated silt loadings on representative paved roads in the Seoul metropolitan area, including the city of Incheon, over a period of 3 yr. The temporal and spatial characteristics of silt loading were investigated for the carefully selected roads that may reflect the characteristics of the cities of Seoul and Incheon. In this study, changes in the average silt loading values were investigated in terms of land use, the temporal resolution of data acquisition (i.e., seasonal, daily, three-hour scale), the road width or number of lanes, and rainfall, which may affect the characteristics of the average silt loading significantly. It was found that the advantages of using the mobile monitoring system are its ability to obtain a large quantity of silt loading data in a short period of time and over a wide area and its ability to create a silt loading map showing the relative magnitude of silt loading in relation to a specific location, which makes it possible to easily locate hot spots.

  20. THE EFFECT OF SALINITY-SODICITY AND GLYPHOSATE FORMULATIONS – AVANS PREMIUM 360 SL ON PHOSPHOMONOESTERASE ACTIVITIES IN SANDY LOAM

    Directory of Open Access Journals (Sweden)

    Maciej Płatkowski

    2016-01-01

    Full Text Available The aim of study was to determine the influence of NaCl and glyphosate-based herbicide Avans Premium 360 SL on acid and alkaline phosphomonoesterase activities in sandy loam. The experiment was carried out in laboratory conditions on sandy loam with Corg content 10.90 g/kg. Soil was divided into half kilogram samples and adjusted to 60% of maximum water holding capacity. In the experiment dependent variables were: I – dosages of Avans Premium 360 SL (0, a recommended field dosage – FD, a tenfold higher dosage – 10 FD and hundredfold higher dosage – 100 FD, II – amount of NaCl (0, 3% and 6%, III – day of experiment (1, 7, 14, 28 and 56. On days of experiment the activity of alkaline and acid phosphomonoesterase activity was assayed spectrophotometrically. The obtained result showed that the application of Avans Premium 360 SL decreased in acid and alkaline phosphomonoesterase activity in clay soil. Significant interaction effect between the dosage of Avans Premium 360 SL, NaCl amount and day of experiment was reported in the experiment. The inhibitory effect of Avans Premium 360 SL was the highest in soil with NaCl at the amount of 6%.

  1. Application of micron X-ray CT based on micro-PIXE to investigate the distribution of Cs in silt particles for environmental remediation in Fukushima Prefecture

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Keizo, E-mail: keizo.ishii@qse.tohoku.ac.jp [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Hatakeyama, Taisuke; Itoh, Shin; Sata, Daichi [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Ohnuma, Tohru; Yamaguchi, Toshiro; Arai, Hiromu; Arai, Hirotsugu [Research Center for Remediation Engineering of Environments Contaminated with Radioisotopes, Graduate School of Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan); Matsuyama, Shigeo; Terakawa, Atsuki; Kim, Seong-Yun [Department of Quantum Science and Energy Engineering, Tohoku University, 6-6-01-2, Aramaki Aza-Aoba, Aoba-ku, Sendai 980-8579 (Japan)

    2016-03-15

    We used X-ray computed tomography (CT) using characteristic X-rays produced in micro-particle-induced X-ray emission (PIXE) to investigate the internal structure of silt particles and develop new methods to decontaminate soil containing radioactive cesium. We obtained 3D attenuation coefficient images of silt particles with a diameter of approximately 100 μm for V K and Cr K X-rays. Owing to the absorption edges of the Cs L-shell, the differences between the V K and Cr K X-ray images revealed the spatial distribution of Cs atoms in the silt particles. Cs atoms were distributed over the surfaces of the silt particles to a thickness of approximately 10 μm. This information is useful for the decontamination of silt contaminated by radiation from the Fukushima Daiichi nuclear disaster.

  2. Preparation and mechanism of the sintered bricks produced from Yellow River silt and red mud

    International Nuclear Information System (INIS)

    He, Hongtao; Yue, Qinyan; Su, Yuan; Gao, Baoyu; Gao, Yue; Wang, Jingzhou; Yu, Hui

    2012-01-01

    Highlights: ► The best condition was red mud content of 40% and sintering at 1050 °C for 2 h. ► Bricks’ weight loss was caused by the removal of absorbed water and crystal water. ► Bricks’ sintering shrinkage depended on the sodium and iron compounds of red mud. ► Sintering can strengthen bricks and decrease leaching concentration of toxic metal. - Abstract: The preparation, characteristics and mechanisms of sintered bricks manufactured by Yellow River silt and red mud were studied. The sintering shrinkage, weight loss on ignition, water absorption and compressive strength were tested to determine the optimum preparation condition. Sintering mechanisms were discussed through linear regression analysis. Crystalline components of raw materials and bricks were analyzed by X-ray diffraction. Leaching toxicity of raw materials and bricks were measured according to sulphuric acid and nitric acid method. Radiation safety of the sintered bricks was characterized by calculating internal exposure index and external exposure index. The results showed that at the chosen best parameters (red mud content of 40%, sintering temperature of 1050 °C and sintering time of 2 h), the best characteristics of sintered bricks could be obtained. The weight loss on ignition of sintered bricks was principally caused by the removal of absorbed water and crystal water. The sintering shrinkage of sintered bricks mainly depended on sodium compounds and iron compounds of red mud. The sintering process made some components of raw materials transform into other crystals having better thermostability. Besides, the leaching toxicity and radioactivity index of sintered bricks produced under the optimum condition were all below standards.

  3. Silt and gas accumulation beneath an artificial recharge spreading basin, Southwestern Utah, U.S.A.

    Science.gov (United States)

    Heilweil, V.M.; Solomon, D.K.; Ortiz, G.

    2009-01-01

    Sand Hollow Reservoir in southwestern Utah, USA, is operated for both surface-water storage and artificial recharge to the underlying Navajo Sandstone. The total volume of estimated artificial recharge between 2002 and 2007 is 85 million cubic meters (69,000 acre-feet). Since 2002, artificial recharge rates have generally been declining and are inversely correlated with the increasing surface area of the reservoir. Permeability testing of core samples retrieved from beneath the reservoir indicates that this decline may not be due to silt accumulation. Artificial recharge rates also show much seasonal variability. Calculations of apparent intrinsic permeability show that these variations can only partly be explained by variation in water viscosity associated with seasonal changes in water temperature. Sporadic seasonal trends in recharge rates and intrinsic permeability during 2002-2004 could be associated with the large fluctuations in reservoir elevation and wetted area. From 2005 through 2007, the reservoir was mostly full and there has been a more consistent seasonal pattern of minimum recharge rates during the summer and maximum rates during the autumn. Total dissolved-gas pressure measurements indicate the presence of biogenic gas bubbles in the shallow sediments beneath the shallower parts of Sand Hollow Reservoir when the water is warmer. Permeability reduction associated with this gas clogging may contribute to the decrease in artificial recharge rates during the spring and summer, with a subsequently increasing recharge rates in the autumn associated with a decline in volume of gas bubbles. Other possible causes for seasonal variation in artificial recharge rates require further investigation.

  4. Interrill sediment enrichment of P and C from organically and conventionally farmed silty loams

    Science.gov (United States)

    Kuhn, N. J.

    2012-04-01

    Globally, between 0.57 and 1.33 Pg of soil organic carbon (SOC) may be affected by interrill processes. Also, a significant amount of phosphorus (P) is contained in the surface soil layer transformed by raindrop impact, runoff and crust formation. In the EU, the P content of a crusted (2 mm) surface layer corresponds to 4 to 40 kg ha-1 of P on arable land (1.094 mil km2). Therefore, the role of interrill processes for nutrient cycling and the global carbon cycle requires close attention. Interrill erosion is a complex phenomen on involving the detachment, transport and deposition of soil particles by raindrop impacted flow. Resistance to interrill erosion varies between soils depending on their physical, chemical and mineralogical properties. In addition, significant changes in soil resistance to interrill erosion occur during storms as a result of changes in surface roughness, cohesion and particle size. As a consequence, erosion on interrill areas is selective, moving the most easily detached small and/or light soil particles. This leads to the enrichment of clay, phosphorous (P)and carbon (C). Such enrichment in interrill sediment is well documented, however, the role of interrill erosion processes on the enrichment remains unclear. Enrichment of P and C in interrill sediment is attributed to the preferential erosion of the smaller, lighter soil particles. In this study, the P and organic C content of sediment generated from two Devon silts under conventional (CS) and organic (OS) soil management were examined. Artificial rainfall was applied to the soils using two rainfall scenarios of differing intensity and kinetic energy to determine the effects on the P and C enrichment in interrill sediment. Interrill soil erodibility was lower on the OS, irrespective of rainfall intensity. Sediment from both soils showed a significant enrichment in P and C compared to the bulk soil. However, sediment from the OS displayed a much greater degree of P enrichment. This shows

  5. Full utilization of silt density index (SDI) measurements for seawater pre-treatment

    KAUST Repository

    Wei, Chunhai

    2012-07-01

    In order to clarify the fouling mechanism during silt density index (SDI) measurements of seawater in the seawater reverse osmosis (SWRO) desalination process, 11 runs were conducted under constant-pressure (207kPa) dead-end filtration mode according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF) and coagulation followed by microfiltration (CMF) technologies were tested. Fouling mechanisms based on the constant-pressure filtration equation were fully analyzed. For all runs, only t/(V/A)∼t showed very good linearity (correlation coefficient R 2>0.99) since the first moment of the filtration, indicating that standard blocking rather than cake filtration was the dominant fouling mechanism during the entire filtration process. The very low concentration of suspended solids rejected by MF of 0.45μm in seawater was the main reason why a cake layer was not formed. High turbidity removal during filtration indicated that organic colloids retained on and/or adsorbed in membrane pores governed the filtration process (i.e., standard blocking) due to the important contribution of organic substances to seawater turbidity in this study. Therefore the standard blocking coefficient k s, i.e., the slope of t/(V/A)∼t, could be used as a good fouling index for seawater because it showed good linearity with feed seawater turbidity. The correlation of SDI with k s and feed seawater quality indicated that SDI could be reliably used for seawater with low fouling potential (SDI 15min<5) like pre-treated seawater in this study. From both k s and SDI, the order of fouling potential was raw seawater>seawater pre-treated by CSF>seawater pre-treated by CMF, indicating the better performance of CMF than CSF. © 2012 Elsevier B.V.

  6. Rheology and zeta potential of cement pastes containing calcined silt and ground granulated blast-furnace slag

    Directory of Open Access Journals (Sweden)

    Safi, B.

    2011-09-01

    Full Text Available This study aimed to analyse the re-use of dam silt as a supplementary binder for self-compacting concrete (SCC. When burnt, silt becomes more reactive because the kaolin it contains is converted into metakaolin. Portland cement, calcined or burnt silt and ground granulated blast furnace slag were used in this research. Cement pastes were prepared with blends containing two or three of these materials. The replacement ratio for burnt silt in both cases was 10 % and 20 % by cement weight and the ratio for the slag was a constant 30 % by weight of the blend. Rheological and zeta potential tests were conducted to evaluate paste electrokinetics and rheological behaviour. The findings showed that burnt silt is apt for use as an addition to cement for SCC manufacture.

    En el presente trabajo se ha analizado la posibilidad de utilizar los lodos procedentes de embalses como adición en la fabricación del hormigón autocompactante (HAC. Con la calcinación, estos materiales se vuelven más reactivos debido a la transformación en metacaolín, del caolín que forma parte de su composición. Las materias primas empleadas en esta investigación son: cemento Pórtland, lodos de embalse calcinados y escorias granuladas de horno alto. Se prepararon pastas de cemento con mezclas que contenían dos o tres de estos materiales. El porcentaje de reemplazo de los lodos calcinados osciló entre el 10 y el 20 % en peso del cemento, mientras que el de la escoria fue del 30 % en peso de la mezcla. Se llevaron a cabo ensayos reológicos y de potencial zeta para evaluar el comportamiento electrocinético y reológico de las distintas pastas. De acuerdo con los resultados obtenidos, una vez calcinados, los lodos de embalse son aprovechables como adición al cemento con destino a la preparación de HAC.

  7. Evaluation of Diuron Tolerance and Biotransformation by Fungi from a Sugar Cane Plantation Sandy-Loam Soil.

    Science.gov (United States)

    Perissini-Lopes, Bruna; Egea, Tássia Chiachio; Monteiro, Diego Alves; Vici, Ana Cláudia; Da Silva, Danilo Grünig Humberto; Lisboa, Daniela Correa de Oliveira; de Almeida, Eduardo Alves; Parsons, John Robert; Da Silva, Roberto; Gomes, Eleni

    2016-12-14

    Microorganisms capable of degrading herbicides are essential to minimize the amount of chemical compounds that may leach into other environments. This work aimed to study the potential of sandy-loam soil fungi to tolerate the herbicide Herburon (50% diuron) and to degrade the active ingredient diuron. Verticillium sp. F04, Trichoderma virens F28, and Cunninghamella elegans B06 showed the highest growth in the presence of the herbicide. The evaluation of biotransformation showed that Aspergillus brasiliensis G08, Aspergillus sp. G25, and Cunninghamella elegans B06 had the greatest potential to degrade diuron. Statistical analysis demonstrated that glucose positively influences the potential of the microorganism to degrade diuron, indicating a cometabolic process. Due to metabolites founded by diuron biotransformation, it is indicated that the fungi are relevant in reducing the herbicide concentration in runoff, minimizing the environmental impact on surrounding ecosystems.

  8. Direct and Indirect Short-term Effects of Biochar on Physical Characteristics of an Arable Sandy Loam

    DEFF Research Database (Denmark)

    Sun, Zhencai; Moldrup, Per; Elsgaard, Lars

    2013-01-01

    Biochar addition to agricultural soil is reported in several studies to reduce climate gas emissions, boost carbon storage, and improve soil fertility and crop productivity. These effects may be partly related to soil physical changes resulting from biochar amendment, but knowledge of how biochar...... application mechanistically affects soil physical characteristics is limited. This study investigated the effect of biochar application on soil structural and functional properties, including specific surface area, water retention, and gas transport parameters. Intact soil cores were taken from a field...... experiment on an arable sandy loam that included four reference plots without biochar and four plots with 20 tons ha(-1) biochar incorporated into the upper 20 cm 7 months before sampling. Water retention was measured at matric potentials ranging from wet (pF 1.0) to extremely dry conditions (pF similar to 6...

  9. Soil water retention, air flow and pore structure characteristics after corn cob biochar application to a tropical sandy loam

    DEFF Research Database (Denmark)

    Amoakwah, Emmanuel; Frimpong, Kwame Agyei; Okae-Anti, D

    2017-01-01

    Soil structure is a key soil physical property that affects soil water balance, gas transport, plant growth and development, and ultimately plant yield. Biochar has received global recognition as a soil amendment with the potential to ameliorate the structure of degraded soils. We investigated how...... corn cob biochar contributed to changes in soil water retention, air flow by convection and diffusion, and derived soil structure indices in a tropical sandy loam. Intact soil cores were taken from a field experiment that had plots without biochar (CT), and plots each with 10 t ha− 1 (BC-10), 20 t ha...... to significant increase in soil water retention compared to the CT and BC-10 as a result of increased microporosity (pores biochar had minimal impact. No significant influence of biochar was observed for ka and Dp/D0 for the BC treatments compared to the CT despite...

  10. Biochar effects on wet and dry regions of the soil water retention curve of a sandy loam

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Moldrup, Per; Sun, Zhencai

    2014-01-01

    Reported beneficial effects of biochar on soil physical properties and processes include decreased soil density, and increased soil water transport, water holding capacity and retention (mainly for the wet region). Research is limited on biochar effects on the full soil water retention curve (wet...... and dry regions) for a given soil and biochar amendment scenarios. This study evaluates how biochar applied to a sandy loam field at rates from 0 to 50 Mg ha−1 yr–1 in 2011, 2012, or both years (2011+2012) influences the full water retention curve. Inorganic fertilizer and pig slurry were added to all...... treatments. Six months after the last biochar application, intact and disturbed soil samples were collected for analyses. Soil water retention was measured from −1 kPa to −100 kPa using tension tables and ceramic plates and from −10 MPa to −480 MPa using a Vapor Sorption Analyzer. Soil specific area...

  11. Influence of Long-term Application of Feedlot Manure Amendments on Water Repellency of a Clay Loam Soil.

    Science.gov (United States)

    Miller, Jim J; Beasley, Bruce W; Hazendonk, Paul; Drury, Craig F; Chanasyk, David S

    2017-05-01

    Long-term application of feedlot manure to cropland may increase the quantity of soil organic carbon (C) and change its quality, which may influence soil water repellency. The objective was to determine the influence of feedlot manure type (stockpiled vs. composted), bedding material (straw [ST] vs. woodchips [WD]), and application rate (13, 39, or 77 Mg ha) on repellency of a clay loam soil after 17 annual applications. The repellency was determined on all 14 treatments using the water repellency index ( index), the water drop penetration time (WDPT) method, and molarity of ethanol (MED) test. The C composition of particulate organic matter in soil of five selected treatments after 16 annual applications was also determined using C nuclear magnetic resonance-direct polarization with magic-angle spinning (NMR-DPMAS). Manure type had no significant ( > 0.05) effect on index and WDPT, and MED classification was similar. Mean index and WDPT values were significantly greater and MED classification more hydrophobic for WD than ST. Application rate had no effect on the index, but WDPT was significantly greater and MED classification more hydrophobic with increasing application rate. Strong ( > 0.7) but nonsignificant positive correlations were found between index and WDPT versus hydrophobic (alkyl + aromatic) C, lignin at 74 ppm (O-alkyl), and unspecified aromatic compounds at 144 ppm. Specific aromatic compounds also contributed more to repellency than alkyl, O-alkyl, and carbonyl compounds. Overall, all three methods consistently showed that repellency was greater for WD- than ST-amended clay loam soil, but manure type had no effect. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  12. Effects of gamma irradiation on some major elements and mating competitiveness of the red Palm Weevil, Rhynchophorus Ferrugineus (OLIVIER), Coleoptera : Curculionidae

    International Nuclear Information System (INIS)

    Mohamed, H.F.; EL-Naggar, S.M.; EL-Kkoly, E.M.S.

    2006-01-01

    In the present study, effects of three gamma doses (5, 10 and 15 Gray) applied to adult male and female weevils of the red palm weevil, Rhynchophorus ferrugineus (Olivier), were investigated. The concentration levels of sodium, potassium, calcium and phosphorous were determined in the haemolymph treated and untreated F1 progeny (males or females) at the 4th instar larvae descendants from irradiated parents male and female weevils. Results indicated that gamma irradiation might have an effect on most investigated elements. No clear relationship could be detected among the applied doses and effect on the level of any of the studied elements. Male mating competitiveness was determined from the egg infertility resulting from F1 males originating from irradiated parental male weevils confined in various ratios with unirradiated adults. Studies comparing mating performance of irradiated males with that of normal males revealed that the mating competitiveness of the irradiated males was increased as the ratio of irradiated to unirradiated males increased from 1 : 1 to 3 : 1 , except at the lesser dose 5 Gy .The results also showed that the infertility was increased as the ratios increased except at the dose rate 10 Gy . The irradiated males were not fully competitive with normal males at the dose 5 Gy among the two ratios 1 : 1 and 3 : 1 and also among the ratio 1:1 at the doses 10 and 15 Gy. The irradiated males were fully competitive with normal males at the doses 10 and 15 Gy among the ratio 3 : 1

  13. Five-grass pollen immunotherapy tablet: an update on the latest findings from clinical trials: an interview with Olivier de Beaumont.

    Science.gov (United States)

    de Beaumont, Olivier; Wilkinson, Jonathan

    2014-01-01

    Interview by Jonathan Wilkinson (Managing Commissioning Editor, Future Science Group). Olivier de Beaumont became Doctor of Medicine at the University of Paris Descartes in 1993. In the same year, he also took a Master of Health Economics degree at Paris Dauphine University. He is also a Master of Business Administration, ESCP Paris, 1999. At Stallergenes, he has been serving as Vice President/Head of Corporate Clinical Development since 2005, responsible for the clinical development plan, clinical operations, biometry and pharmacovigilance. In 2011, he took the responsibility of Senior Vice President Global Medical Affairs responsible for medical information and education, medical communication and nonregistration clinical studies. In 2014 he became Senior Vice President Global Scientific and Medical Affairs. From 2002 to 2005 he led the European business development of the world's leading clinical research organization Quintiles, developing Phase I-IV clinical trial programs for pharmaceutical companies. Previous roles included: Chief Scientific Officer and cofounder of Direct Medica (2000-2002), product champion and lifecycle management at Aventis (1998-2000), medical affairs manager in oncology and respiratory diseases at corporate Rhone-Poulenc Rorer (1993-1998).

  14. Sterilizing effects and lethal effects of gamma radiation on different phases of life cycle of the sitotroga cerealella (Olivier) in rice and maize

    International Nuclear Information System (INIS)

    Arthur, V.

    1985-01-01

    The objective of this research to verify the effects of the gamma radiation on different phases of the life cycle of the gamma radiation on different phases of the life cycle of the moth grain Angoumois, Sitotroga cerealella (Olivier, 1819). For all the treatment with gamma radiation a Cobalt-60 source type Gammabeam-650 was used and the activity was approximately 3.1 x 10 sup(14) Bq., with dose rate of 3.01 kGy per hour. The LD sub(100) of gamma radiation for eggs of insects reared in rice and maize were respectively 100 Gy and 125 Gy. The sterilizing doses in adults which were irradiated at immature phases (larvae and pupae) were 100 Gy and 200 Gy in rice and 150 Gy and 250 Gy in maize, respectively. The sterilizing doses for females and males in maize were respectively 350 Gy and 500 Gy. The LD sub(100) for adult females were 4500 Gy and 4750 Gy for males, both in rice. The LD sub(100), for adult reared on maize was 4750 Gy for both sexes. (author)

  15. Effect of Simulated Weathering and Aging of TNT in Amended Sandy Loam Soil on Toxicity to the Enchytraeid Worm, Enchytreaeus Crypticus

    Science.gov (United States)

    2006-05-01

    high bioavailability of organic compounds. However, amended SSL soil was analyzed for presence of metabolic transformation products from nitroaromatic...Phillips, C.; Checkai, R. 1999. Comparison of malathion toxicity using enchytraeid reproduction test and earthworm toxicity test in different soil ...OF TNT IN AMENDED SANDY LOAM SOIL ON TOXICITY TO THE ENCHYTRAEID WORM, ENCHYTRAEUS CRYPTICUS Roman G. Kuperman Ronald T. Checkai Michael Simini

  16. Testing Re-entrained Aerosol Kinetic Emissions from Roads : a new approach to infer silt loading on roadways

    Science.gov (United States)

    Kuhns, H.; Etyemezian, V.; Landwehr, D.; MacDougall, C.; Pitchford, M.; Green, M.

    PM 10 and PM 2.5 emissions from roadways are currently estimated using the silt loading on the road surface as a surrogate for the emissions potential of road dust. While the United States Environmental Protection Agency prescribes this method in AP-42, there is considerable cost associated with silt loading measurements; it is feasible to sample only a small portion of a roadway network. A new approach for measuring the concentration of suspendable PM 10 above road surfaces has been developed to obtain a more spatially representative estimate of a road's potential to emit dust. The Testing Re-entrained Aerosols Kinetic Emissions from Roads (TRAKER) system uses real-time aerosol sensors mounted on a vehicle to measure the concentration of dust suspended from the road while the vehicle is in motion. When coupled with a Global Positioning System (GPS) instrument, TRAKER can be used to efficiently survey the changes in suspendable particles due to varying road conditions over a large spatial domain. In a recent study on paved roads in Las Vegas, the TRAKER system was compared with collocated silt loading measurements. The TRAKER system was also used to survey the relative amounts of suspendable road dust on approximately 300 miles of paved roads. The system provides a unique perspective on road dust sources and their spatial distribution. Results of this study indicated that the difference of the PM 10 concentrations measured behind the tire and on the hood is exponentially related to vehicle speed. This was an interesting finding because current AP-42 road dust emissions estimation methods do not include vehicle speed as a factor in the emissions calculations. The experiment also demonstrated that the distribution of suspendable material on roadways is highly variable and that a large number of samples are needed to represent road dust emissions potential on an urban scale for a variety of road and activity conditions.

  17. Carbon sequestration in clay and silt fractions of Brazilian soils under conventional and no-tillage systems

    Directory of Open Access Journals (Sweden)

    Cecília Estima Sacramento dos Reis

    2014-08-01

    Full Text Available The capacity of soils to sequestrate carbon (C is mainly related to the formation of organo-mineral complexes. In this study, we investigated the influence of soil management systems on the C retention capacity of soil with an emphasis on the silt and clay fractions of two subtropical soils with different mineralogy and climate. Samples from a Humic Hapludox and a Rhodic Hapludox, clayey soils cultivated for approximately 30 years under no-tillage (NT and conventional tillage (CT were collected from six layers distributed within 100-cm soil depth from each site and from an adjacent native forest. After the removal of particulate organic matter (POM, the suspension (<53 µm was sonicated, the silt and clay fractions were separated in accordance with Stokes' law and the carbon content of whole soil and physical fractions was determined. In the Humic Hapludox, the clay and silt fractions under NT showed a higher maximum C retention (72 and 52 g kg-1, respectively in comparison to those under CT (54 and 38 g kg-1, respectively. Moreover, the C concentration increase in both fractions under NT occurred mainly in the topsoil (up to 5 cm. The C retention in physical fractions of Rhodic Hapludox varied from 25 to 32 g kg-1, and no difference was observed whether under an NT or a CT management system. The predominance of goethite and gibbsite in the Humic Hapludox, as well as its exposure to a colder climate, may have contributed to its greater C retention capacity. In addition to the organo-mineral interaction, a mechanism of organic matter self-assemblage, enhanced by longer periods of soil non-disturbance, seems to have contributed to the carbon stabilization in both soils.

  18. PGRP-LB homolog acts as a negative modulator of immunity in maintaining the gut-microbe symbiosis of red palm weevil, Rhynchophorus ferrugineus Olivier.

    Science.gov (United States)

    Dawadi, Bishnu; Wang, Xinghong; Xiao, Rong; Muhammad, Abrar; Hou, Youming; Shi, Zhanghong

    2018-09-01

    Many notorious insect pests live in the symbiotic associations with gut microbiota. However, the mechanisms underlying how they host their gut microbiota are unknown. Most gut bacteria can release peptidoglycan (PGN) which is an important antigen to activate the immune response. Therefore, how to keep the appropriate gut immune intensity to host commensals while to efficiently remove enteropathogens is vital for insect health. This study is aimed at elucidating the roles of an amidase PGRP, Rf PGRP-LB, in maintaining the gut-microbe symbiosis of Red palm weevil (RPW), Rhynchophorus ferrugineus Olivier. RfPGRP-LB is a secreted protein containing a typical PGRP domain. The existence of five conservative amino acid residues, being required for amidase activity, showed that RfPGRP-LB is a catalytic protein. Expression analysis revealed abundance of RfPGRP-LB transcripts in gut was dramatically higher than those in other tissues. RfPGRP-LB could be significantly induced against the infection of Escherichia coli. In vitro assays revealed that rRfPGRP-LB impaired the growth of E. coli and agglutinated bacteria cells obviously, suggesting RfPGRP-LB is a pathogen recognition receptor and bactericidal molecule. RfPGRP-LB knockdown reduced the persistence of E. coli in gut and load of indigenous gut microbiota significantly. Furthermore, the community structure of indigenous gut microbiota was also intensively altered by RfPGRP-LB silence. Higher levels of the antimicrobial peptide, attacin, were detected in guts of RfPGRP-LB silenced larvae than controls. Collectively, RfPGRP-LB plays multiple roles in modulating the homeostasis of RPW gut microbiota not only by acting as a negative regulator of mucosal immunity through PGN degradation but also as a bactericidal effector to prevent overgrowth of commensals and persistence of noncommensals. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Uncertainty of Deardorff’s soil moisture model based on continuous TDR measurements for sandy loam soil

    Directory of Open Access Journals (Sweden)

    Brandyk Andrzej

    2016-03-01

    Full Text Available Knowledge on soil moisture is indispensable for a range of hydrological models, since it exerts a considerable influence on runoff conditions. Proper tools are nowadays applied in order to gain in-sight into soil moisture status, especially of uppermost soil layers, which are prone to weather changes and land use practices. In order to establish relationships between meteorological conditions and topsoil moisture, a simple model would be required, characterized by low computational effort, simple structure and low number of identified and calibrated parameters. We demonstrated, that existing model for shallow soils, considering mass exchange between two layers (the upper and the lower, as well as with the atmosphere and subsoil, worked well for sandy loam with deep ground water table in Warsaw conurbation. GLUE (Generalized Likelihood Uncertainty Estimation linked with GSA (Global Sensitivity Analysis provided for final determination of parameter values and model confidence ranges. Including the uncertainty in a model structure, caused that the median soil moisture solution of the GLUE was shifted from the one optimal in deterministic sense. From the point of view of practical model application, the main shortcoming were the underestimated water exchange rates between the lower soil layer (ranging from the depth of 0.1 to 0.2 m below ground level and subsoil. General model quality was found to be satisfactory and promising for its utilization for establishing measures to regain retention in urbanized conditions.

  20. Field Performance of Nine Soil Water Content Sensors on a Sandy Loam Soil in New Brunswick, Maritime Region, Canada

    Directory of Open Access Journals (Sweden)

    Lionel Stevens

    2009-11-01

    Full Text Available An in situ field test on nine commonly-used soil water sensors was carried out in a sandy loam soil located in the Potato Research Center, Fredericton, NB (Canada using the gravimetric method as a reference. The results showed that among the tested sensors, regardless of installation depths and soil water regimes, CS615, Trase, and Troxler performed the best with the factory calibrations, with a relative root mean square error (RRMSE of 15.78, 16.93, and 17.65%, and a r2 of 0.75, 0.77, and 0.65, respectively. TRIME, Moisture Point (MP917, and Gopher performed slightly worse with the factory calibrations, with a RRMSE of 45.76, 26.57, and 20.41%, and a r2 of 0.65, 0.72, and 0.78, respectively, while the Gypsum, WaterMark, and Netafim showed a frequent need for calibration in the application in this region.

  1. Empirical Models for Power and Energy Requirements II : A Powered Implement Operation in Serdang Sandy Clay Loam, Malaysia

    Directory of Open Access Journals (Sweden)

    A. F. Kheiralla

    2017-12-01

    Full Text Available Power and energy requirements were measured with an instrumented tractor for rotary tilling in Serdang sandy clay loam soil.  The effects of travel speed and rotor speed upon the measured data were investigated.  Power model from orthogonal regression analysis was formulated based on linear and quadratic functions of travel speed and bite length.  Fuel consumption model from regression analysis was formulated based on linear tractor PTO power as well as linear equivalent tractor PTO power.  Fuel consumption rates predicted by ASAE D497.3 were found to be 25% to 28% overestimates of the values predicted by the model developed.  However, fuel consumption rates reported by OECD Tractor Test were found to be 1% to 9% lower than the fuel consumption rates predicted by the model developed.  A comparison of power and energy requirements for both powered and draught implements showed that the disk harrow was the most energy efficient implement in terms of fuel consumption and specific energy followed by the rotary tiller, disk plough and mouldboard.  Finally, average PTO power, fuel consumption, wheel slip, wheel power and specific energy for a powered implement are presented.

  2. The fate of fresh and stored 15N-labelled sheep urine and urea applied to a sandy and a sandy loam soil using different application strategies

    DEFF Research Database (Denmark)

    Sørensen, P.; Jensen, E.S.

    1996-01-01

    The fate of nitrogen from N-15-labelled sheep urine and urea applied to two soils was studied under field conditions. Labelled and stored urine equivalent to 204 kg N ha(-1) was either incorporated in soil or applied to the soil surface prior to sowing of Italian ryegrass (Lolium multiflorum L...... and soil was not significantly different for incorporated urine and urea. Almost all the supplied labelled N was accounted for in soil and herbage in the sandy loam soil, whereas 33-34% of the labelled N was unaccounted for in the sandy soil. When the stored urine was applied to the soil surface, 20...... was applied to growing ryegrass at the sandy loam soil, the immobilization of urine-derived N was significantly reduced compared to application prior to sowing. The results indicated that the net mineralization of urine N was similar to that of urea in the sandy soil, but only about 75% of the urine N was net...

  3. Upper Pleistocene turbidite sand beds and chaotic silt beds in the channelized, distal, outer-fan lobes of the Mississippi fan

    Science.gov (United States)

    Nelson, C.H.; Twichell, D.C.; Schwab, W.C.; Lee, H.J.; Kenyon, Neil H.

    1992-01-01

    Cores from a Mississippi outer-fan depositional lobe demonstrate that sublobes at the distal edge contain a complex local network of channelized-turbidite beds of graded sand and debris-flow beds of chaotic silt. Off-lobe basin plains lack siliciclastic coarse-grained beds. The basin-plain mud facies exhibit low acoustic backscatter on SeaMARC IA sidescan sonar images, whereas high acoustic backscatter characteristic of the lobe sand and silt facies. The depth of the first sand-silt layer correlates with relative backscatter intensity and stratigraphic age of the distal sublobes (i.e., shallowest sand = highest backscatter and youngest sublobe). The high proportion (>50%) of chaotic silt compared to graded sand in the distal, outer-fan sublobes may be related to the unstable, muddy, canyon-wall source areas of the extensive Mississippi delta-fed basin slope. A predominace of chaotic silt in cores or outcrops from outer-fan lobes thus may predict similar settings for ancient fans.

  4. Crop uptake and leaching losses of 15N labelled fertilizer nitrogen in relation to waterlogging of clay and sandy loam soils

    International Nuclear Information System (INIS)

    Webster, C.P.; Belford, R.K.; Cannell, R.Q.

    1986-01-01

    Ammonium nitrate fertilizer, labelled with 15 N, was applied in spring to winter wheat growing in undisturbed monoliths of clay and sandy loam soil in lysimeters; the rates of application were respectively 95 and 102 kg N ha -1 in the spring of 1976 and 1975. Crops of winter wheat, oilseed rape, peas and barley grown in the following 5 or 6 years were treated with unlabelled nitrogen fertilizer at rates recommended for maximum yields. During each year of the experiments the lysimeters were divided into treatments which were either freely drained or subjected to periods of waterlogging. Another labelled nitrogen application was made in 1980 to a separate group of lysimeters with a clay soil and a winter wheat crop to study further the uptake of nitrogen fertilizer in relation to waterlogging. In the first growing season, shoots of the winter wheater at harvest contained 46 and 58% of the fertilizer nitrogen applied to the clay and sandy loam soils respectively. In the following year the crops contained a further 1-2% of the labelled fertilizer, and after 5 and 6 years the total recoveries of labelled fertilizer in the crops were 49 and 62% on the clay and sandy loam soils respectively. In the first winter after the labelled fertilizer was applied, less than 1% of the fertilizer was lost in the drainage water, and only about 2% of the total nitrogen (mainly nitrate) in the drainage water from both soils was derived from the fertilizer

  5. Elevated gas hydrate saturation within silt and silty clay sediments in the Shenhu area, South China Sea

    Science.gov (United States)

    Wang, Xiujuan; Hutchinson, Deborah R.; Wu, Shiguo; Yang, Shengxiong; Guo, Yiqun

    2011-01-01

    Gas hydrate saturations were estimated using five different methods in silt and silty clay foraminiferous sediments from drill hole SH2 in the South China Sea. Gas hydrate saturations derived from observed pore water chloride values in core samples range from 10 to 45% of the pore space at 190–221 m below seafloor (mbsf). Gas hydrate saturations estimated from resistivity (Rt) using wireline logging results are similar and range from 10 to 40.5% in the pore space. Gas hydrate saturations were also estimated by P wave velocity obtained during wireline logging by using a simplified three-phase equation (STPE) and effective medium theory (EMT) models. Gas hydrate saturations obtained from the STPE velocity model (41.0% maximum) are slightly higher than those calculated with the EMT velocity model (38.5% maximum). Methane analysis from a 69 cm long depressurized core from the hydrate-bearing sediment zone indicates that gas hydrate saturation is about 27.08% of the pore space at 197.5 mbsf. Results from the five methods show similar values and nearly identical trends in gas hydrate saturations above the base of the gas hydrate stability zone at depths of 190 to 221 mbsf. Gas hydrate occurs within units of clayey slit and silt containing abundant calcareous nannofossils and foraminifer, which increase the porosities of the fine-grained sediments and provide space for enhanced gas hydrate formation. In addition, gas chimneys, faults, and fractures identified from three-dimensional (3-D) and high-resolution two-dimensional (2-D) seismic data provide pathways for fluids migrating into the gas hydrate stability zone which transport methane for the formation of gas hydrate. Sedimentation and local canyon migration may contribute to higher gas hydrate saturations near the base of the stability zone.

  6. Impacts of soil conditioners and water table management on phosphorus loss in tile drainage from a clay loam soil.

    Science.gov (United States)

    Zhang, T Q; Tan, C S; Zheng, Z M; Welacky, T W; Reynolds, W D

    2015-03-01

    Adoption of waste-derived soil conditioners and refined water management can improve soil physical quality and crop productivity of fine-textured soils. However, the impacts of these practices on water quality must be assessed to ensure environmental sustainability. We conducted a study to determine phosphorus (P) loss in tile drainage as affected by two types of soil conditioners (yard waste compost and swine manure compost) and water table management (free drainage and controlled drainage with subirrigation) in a clay loam soil under corn-soybean rotation in a 4-yr period from 1999 to 2003. Tile drainage flows were monitored and sampled on a year-round continuous basis using on-site auto-sampling systems. Water samples were analyzed for dissolved reactive P (DRP), particulate P (PP), and total P (TP). Substantially greater concentrations and losses of DRP, PP, and TP occurred with swine manure compost than with control and yard waste compost regardless of water table management. Compared with free drainage, controlled drainage with subirrigation was an effective way to reduce annual and cumulative losses of DRP, PP, and TP in tile drainage through reductions in flow volume and P concentration with control and yard waste compost but not with swine manure compost. Both DRP and TP concentrations in tile drainage were well above the water quality guideline for P, affirming that subsurface loss of P from fine-textured soils can be one critical source for freshwater eutrophication. Swine manure compost applied as a soil conditioner must be optimized by taking water quality impacts into consideration. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  7. Nitrogen Amendment Stimulated Decomposition of Maize Straw-Derived Biochar in a Sandy Loam Soil: A Short-Term Study.

    Directory of Open Access Journals (Sweden)

    Weiwei Lu

    Full Text Available This study examined the effect of nitrogen (N on biochar stability in relation to soil microbial community as well as biochar labile components using δ13C stable isotope technology. A sandy loam soil under a long-term rotation of C3 crops was amended with biochar produced from maize (a C4 plant straw in absence (BC0 and presence (BCN of N and monitored for dynamics of carbon dioxide (CO2 flux, phospholipid fatty acids (PLFAs profile and dissolved organic carbon (DOC content. N amendment significantly increased the decomposition of biochar during the first 5 days of incubation (P < 0.05, and the proportions of decomposed biochar carbon (C were 2.30% and 3.28% in BC0 and BCN treatments, respectively, during 30 days of incubation. The magnitude of decomposed biochar C was significantly (P < 0.05 higher than DOC in biochar (1.75% and part of relatively recalcitrant biochar C was mineralized in both treatments. N amendment increased soil PLFAs concentration at the beginning of incubation, indicating that microorganisms were N-limited in test soil. Furthermore, N amendment significantly (P < 0.05 increased the proportion of gram-positive (G+ bacteria and decreased that of fungi, while no noticeable changes were observed for gram-negative (G- bacteria and actinobacteria at the early stage of incubation. Our results indicated that N amendment promoted more efficiently the proliferation of G+ bacteria and accelerated the decomposition of relatively recalcitrant biochar C, which in turn reduced the stability of maize straw-derived biochar in test soil.

  8. Olivier Chanel et Guillaume Faburel (dir., 2010, L’Environnement dans la décision publique : Refonder l’évaluation socio-économique pour des politiques de transport plus durables, Economica, Paris, 230 p.

    Directory of Open Access Journals (Sweden)

    Adrien de Abreu

    2010-09-01

    Full Text Available Quid des impacts environnementaux dans l’évaluation socio-économique des projets d’infrastructure ? C’est sous l’angle des équipements de transport que les auteurs abordent cette question, dirigés par Olivier Chanel et Guillaume Faburel. Olivier Chanel est chercheur en économie de l’environnement au sein du GREQAM (Groupement de recherche en économie quantitative d’Aix-Marseille. Guillaume Faburel est Maître de conférences à l’Université Paris 12 - Val de Marne et chercheur au CRETEIL (Centr...

  9. Fate of corrosion products released from stainless steel in marine sediments and seawater. Part 2. Sequim Bay clayey silt

    International Nuclear Information System (INIS)

    Schmidt, R.L.

    1982-04-01

    This report describes laboratory experiments in which neutron-activated 347 stainless steel specimens were exposed to clayey silt from Sequim Bay, Washington. The properties and trace metal geochemistry of the sediment and the amounts of corrosion products that were released under oxic and reduced conditions and their distribution among different chemical fractions of the sediment are discussed. The distributions of Cr, Mn, Fe, Ni and Cu among different chemical forms in the Sequim Bay sediment show that DTPA removed <10% of extractable Cr, Fe and Mn, approx. 20% of extractable Ni and approx. 30% of extractable Cu. The inorganic fraction (material soluble in 2.5% acetic acid) accounted for approx. 30% of total extractable Mn and approx. 10% or less of Cr, Fe, Ni and Cu. Major portions of Cr and Cu, and a large amount of Fe were in the organic fraction. Extractable Mn, Fe and Ni were associated with hydrous oxides likely as coatings on the mineral substrate of the sediment. No Co was detectable in any of the extracts

  10. Rapid runoff via shallow throughflow and deeper preferential flow in a boreal catchment underlain by frozen silt (Alaska, USA)

    Science.gov (United States)

    Koch, Joshua C.; Ewing, Stephanie A.; Striegl, Robert G.; McKnight, Diane M.

    2013-01-01

    In high-latitude catchments where permafrost is present, runoff dynamics are complicated by seasonal active-layer thaw, which may cause a change in the dominant flowpaths as water increasingly contacts mineral soils of low hydraulic conductivity. A 2-year study, conducted in an upland catchment in Alaska (USA) underlain by frozen, well-sorted eolian silt, examined changes in infiltration and runoff with thaw. It was hypothesized that rapid runoff would be maintained by flow through shallow soils during the early summer and deeper preferential flow later in the summer. Seasonal changes in soil moisture, infiltration, and runoff magnitude, location, and chemistry suggest that transport is rapid, even when soils are thawed to their maximum extent. Between June and September, a shift occurred in the location of runoff, consistent with subsurface preferential flow in steep and wet areas. Uranium isotopes suggest that late summer runoff erodes permafrost, indicating that substantial rapid flow may occur along the frozen boundary. Together, throughflow and deep preferential flow may limit upland boreal catchment water and solute storage, and subsequently biogeochemical cycling on seasonal to annual timescales. Deep preferential flow may be important for stream incision, network drainage development, and the release of ancient carbon to ecosystems

  11. Parametric study of the physical properties of hydrate-bearing sand, silt, and clay sediments: 1. Electromagnetic properties

    Science.gov (United States)

    Lee, J.Y.; Santamarina, J.C.; Ruppel, C.

    2010-01-01

    The marked decrease in bulk electrical conductivity of sediments in the presence of gas hydrates has been used to interpret borehole electrical resistivity logs and, to a lesser extent, the results of controlled source electromagnetic surveys to constrain the spatial distribution and predicted concentration of gas hydrate in natural settings. Until now, an exhaustive laboratory data set that could be used to assess the impact of gas hydrate on the electromagnetic properties of different soils (sand, silt, and clay) at different effective stress and with different saturations of hydrate has been lacking. The laboratory results reported here are obtained using a standard geotechnical cell and the hydrate-formed tetrahydrofuran (THF), a liquid that is fully miscible in water and able to produce closely controlled saturations of hydrate from dissolved phase. Both permittivity and electrical conductivity are good indicators of the volume fraction of free water in the sediment, which is in turn dependent on hydrate saturation. Permittivity in the microwave frequency range is particularly predictive of free water content since it is barely affected by ionic concentration, pore structure, and surface conduction. Electrical conductivity (or resistivity) is less reliable for constraining water content or hydrate saturation: In addition to fluid-filled porosity, other factors, such as the ionic concentration of the pore fluid and possibly other conduction effects (e.g., surface conduction in high specific surface soils having low conductivity pore fluid), also influence electrical conductivity.

  12. Weeds of cereal stubble-fields on various soils in the Kielce region. P. 1. Podzolic and brown soils developed from sands and loams

    Directory of Open Access Journals (Sweden)

    Franciszek Pawłowski

    2013-12-01

    Full Text Available Occupying cereal stubble-fields weed flora is the most characteristic of the environmental (especially soil conditions. Because of its developing and accomplishing the reproductive stages there it can threatens cultivated plants. They are considered to complete the seed store in a soil by 393 min per ha. The results presented in the paper concern the species composition, number and constancy (S and indice of coverage (D of the cereal stubble-field weed species on various soils in the Kielce region (the central part of Poland. The report was based upon 885 phytosociological records collected in the 268 stands. The records were carried out after the crop harvest, in the latter part of September, in 1976-1980. Soil were chosen on the base of soil maps. The analyse of soil samples, taken at the investigation process, were done in order to confirm the soil quality. The worked out material was divided into three parts. The first part, including 369 phytosociological records collected in the 112 stands (in 90 localities concerns stubble-field weeds on podzolic and brown soils developed from sands (loose, weakly loamy and loamy and loams (light and medium. It was found that these soils were grown by 108 (loamy sands to 132 (weakly loamy sands weed species. Among them 66 species were common for all of the soils. Species composition was not differentiated by the soil type (brown, podzolic within kind of the. soil (sand or loams. Among soil examined, the brown loams was the most abundant with species of high constancy degree (30 species but brown loose sands and podzolic loamy sands was the poorest one with (16 species.

  13. Changes to soil water content and biomass yield under combined maize and maize-weed vegetation with different fertilization treatments in loam soil

    Directory of Open Access Journals (Sweden)

    Lehoczky Éva

    2016-06-01

    Full Text Available Especially during early developmental stages, competition with weeds can reduce crop growth and have a serious effect on productivity. Here, the effects of interactions between soil water content (SWC, nutrient availability, and competition from weeds on early stage crop growth were investigated, to better understand this problem. Field experiments were conducted in 2013 and 2014 using long-term study plots on loam soil in Hungary. Plots of maize (Zea mays L. and a weed-maize combination were exposed to five fertilization treatments. SWC was observed along the 0–80 cm depth soil profile and harvested aboveground biomass (HAB was measured.

  14. Effect of organic amendments on nitrate leaching mitigation in a sandy loam soil of Shkodra district, Albania

    Directory of Open Access Journals (Sweden)

    Erdona Demiraj

    2018-03-01

    Full Text Available European lacustrine systems are frequently exposed to nitrate (NO3– pollution causing eutrophication processes. An example of these lakes is Shkodra Lake, a large, shallow lake shared by Albania and Montenegro, in the Balkans Peninsula. Shkodra Lake is a natural sink that collects NO3– from agricultural activities, widely diffused in the surrounding area. The additions of wheat straw and biochar have been suggested to increase soil NO3– retention of agricultural lands. To better understand the role of these two organic soil amendments in mitigating NO3– leaching from arable lands, a pot experiment using a representative sandy loam soil of the Skodra Lake basin was performed. More specifically, a greenhouse experiment with Lolium multiflorum L. and Zea mays L., was carried out for three months, to evaluate the concentrations of NO3–-N in leachate and the cumulative leaching losses of NO3–-N, after wheat straw (10 Mg ha–1 and biochar (10 Mg ha–1 soil addition, under the same rate of NPK fertiliser (300 kg ha–1. The effect of the two organic amendments on nitrate retention, was evaluated according to two methods: i Soil NO3–-N leaching with distilled water; and ii Soil NO3–-N extraction with 2M KCl. The leached NO3–-N and the Potentially Leachable NO3–-N (2M KCl extraction were respectively determined. N uptake by plants, as well as the Nitrogen Use Efficiency were also calculated. A retention effect on nitrate was found in Lolium multiflorum L. and wheat straw treatments compared to control, by reducing leached NO3–-N almost to 35%. In SBFL (soil+biochar+fertiliser+Lolium treatment, biochar effectively reduced the total amount of nitrate in leachate of 27% and 26% compared to SFL (soil+fertiliser+Lolium and SSFL (soil+straw+fertiliser+Lolium treatments, respectively. The potentially leachable NO3–-N was two to four times higher than the leached NO3–-N. The amount of potentially leachable NO3–-N per hectare ranged

  15. Relation of sortable silt grain-size to deep-sea current speeds: Calibration of the 'Mud Current Meter'

    Science.gov (United States)

    McCave, I. N.; Thornalley, D. J. R.; Hall, I. R.

    2017-09-01

    Fine grain-size parameters have been used for inference of palaeoflow speeds of near-bottom currents in the deep-sea. The basic idea stems from observations of varying sediment size parameters on a continental margin with a gradient from slower flow speeds at shallower depths to faster at deeper. In the deep-sea, size-sorting occurs during deposition after benthic storm resuspension events. At flow speeds below 10-15 cm s-1 mean grain-size in the terrigenous non-cohesive 'sortable silt' range (denoted by SS bar , mean of 10-63 μm) is controlled by selective deposition, whereas above that range removal of finer material by winnowing is also argued to play a role. A calibration of the SS bar grain-size flow speed proxy based on sediment samples taken adjacent to sites of long-term current meters set within 100 m of the sea bed for more than a year is presented here. Grain-size has been measured by either Sedigraph or Coulter Counter, in some cases both, between which there is an excellent correlation for SS bar (r = 0.96). Size-speed data indicate calibration relationships with an overall sensitivity of 1.36 ± 0.19 cm s-1/μm. A calibration line comprising 12 points including 9 from the Iceland overflow region is well defined, but at least two other smaller groups (Weddell/Scotia Sea and NW Atlantic continental rise/Rockall Trough) are fitted by sub-parallel lines with a smaller constant. This suggests a possible influence of the calibre of material supplied to the site of deposition (not the initial source supply) which, if depleted in very coarse silt (31-63 μm), would limit SS bar to smaller values for a given speed than with a broader size-spectrum supply. Local calibrations, or a core-top grain-size and local flow speed, are thus necessary to infer absolute speeds from grain-size. The trend of the calibrations diverges markedly from the slope of experimental critical erosion and deposition flow speeds versus grain-size, making it unlikely that the SS bar (or

  16. Interaction of the heavy metals (Cr +6, Cd, Pb, Ni) between the silt and the water column in the case study of Bogota River

    International Nuclear Information System (INIS)

    Pinzon U, L.F.; Rodriguez, J.A.; Giraldo, E.

    1993-01-01

    For the present study the Bogota River it uses as framework, this river has a course of 255 km., in it pathway through 26 municipalities, including the Western area of the District Capital (Bogota). In the District Capital area, some significant sampling points were founded, due to their localization on the bed and that industrial activities of grateful polluting function are developed. Silt samples were extracted and it dilutes for chemical-physical analysis and study to scale; these samples were implanted in columns or reactors; one of characteristic totally anaerobic and another of characteristic aerobic. Of equal forms it procedure is repeated, but replacing the river water for dilution water; every third day the extracted samples are been about agreement with the metal to analyze Chromium IV for the waters, Total Chromium for the silts, Cadmium, Lead and Total Nickel in the column of water and silts to be analyzed by means of Absorption Atomic Spectrophotometry. The object is the one of establishing that exchange type is presented between the polluted water and the water free of contaminants

  17. Consolidation and compaction as a means to prevent settlement of bentonite/sandy silt mixes for use in waste disposal sites

    International Nuclear Information System (INIS)

    Abeele, W.V.

    1985-01-01

    The texture of the local Los Alamos tuff is that of a sandy silt with a high hydraulic conductivity. The permeability is dramatically decreased by addition of small amounts of bentonite. The coefficient of consolidation for bentonite/sandy silt ratios decreases inversely proportional with the square of that ratio, whereas the compression index, the swelling index, and the permeability change index increase with increasing bentonite ratio. A strong relationship also exists between the void ratio and the logarithm of the applied stress for any given bentonite ratio. The empirical linear relationship between the void ratio and the logarithm of the applied stress, developed by Taylor, is excellent and enables us to limit the evaluation of conductivity at any void ratio to the measurement of the initial and the desired void ratio, the initial conductivity, and the permeability change index. The decrease in void ratio caused by consolidation or natural compaction of the mixes are scrutinized. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of bentonite/sandy silt mixes. Remedial actions, i.e., means to limit the amount of settlement, are considered. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. 15 refs., 5 tabs

  18. Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

    KAUST Repository

    Serrano, Oscar

    2016-09-07

    The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (C-org) content in terrestrial soils and marine sediments has been correlated with mud content (i.e., silt and clay, particle sizes <63 mu m), however, empirical tests of this theory are lacking for coastal vegetated ecosystems. Here, we compiled data (n = 1345) on the relationship between C-org and mud contents in seagrass ecosystems (79 cores) and adjacent bare sediments (21 cores) to address whether mud can be used to predict soil C-org content. We also combined these data with the delta C-13 signatures of the soil C-org to understand the sources of Corg stores. The results showed that mud is positively correlated with soil C-org content only when the contribution of seagrass-derived C-org to the sedimentary C-org pool is relatively low, such as in small and fast-growing meadows of the genera Zostera, Halodule and Halophila, and in bare sediments adjacent to seagrass ecosystems. In large and long-living seagrass meadows of the genera Posidonia and Amphibolis there was a lack of, or poor relationship between mud and soil C-org content, related to a higher contribution of seagrass-derived C-org to the sedimentary C-org pool in these meadows. The relatively high soil C-org contents with relatively low mud contents (e.g., mud-C-org saturation) in bare sediments and Zostera, Halodule and Halophila meadows was related to significant allochthonous inputs of terrestrial organic matter, while higher contribution of seagrass detritus in Amphibolis and Posidonia meadows disrupted the correlation expected between soil C-org and mud contents. This study shows that mud is not a universal proxy for blue carbon content in seagrass ecosystems, and therefore should not be applied generally across all seagrass habitats. Mud content can only be used as a proxy to estimate soil C-org content for

  19. Discriminating silt-and-clay from suspended-sand in rivers using side-looking acoustic profilers

    Science.gov (United States)

    Wright, Scott A.; Topping, David J.; Williams, Cory A.

    2010-01-01

    techniques rely on measurements of ancillary properties that correlate with suspended-sediment concentration and particle size and thus require the collection of traditional samples for calibration. Through in situ deployments, these methods can provide the high temporal resolution that cannot be achieved through traditional sampling. Here we focus on the evaluation of acoustic profiling techniques (e.g. acoustic-Doppler sideways-looking profilers, or ADPs). One major advantage of acoustic profiling is the ability to concurrently measure water velocity (using Doppler-shift methods) and suspended-sediment concentration such that suspended-sediment flux can be directly computed using data from a single instrument. Acoustic-Doppler profilers have become popular for measuring water velocity and discharge in rivers, through both moving-boat operations and from fixed deployments such as bank-mounted sideways-looking instruments (Hirsch and Costa, 2004, Muste et al., 2007). The method presented herein is most suited to sideways-looking applications as a complement to the "index velocity" technique, whereby an index velocity from a sideways-looking instrument is related to the cross-section average velocity (determined from moving-boat discharge measurements) as a means for developing a continuous water-discharge record (Ruhl and Simpson, 2005). Topping et al. (2007) presented a method for discriminating silt-and-clay from suspended sand, using single frequency ADPs. This method takes advantage of the relations among acoustic backscatter, sediment-induced acoustic attenuation, suspended-sediment concentration (SSC), and particle size distribution (PSD). Backscatter is the amount of sound scattered back and received at the transducer while sediment-induced attenuation is the amount of sound scattered in other directions and absorbed by the sediment particles. Both of these parameters can be measured with an ADP, and their different dependencies on SSC and PSD allow for the

  20. USE OF THE “ROTHC” MODEL TO SIMULATE SOIL ORGANIC CARBON DYNAMICS ON A SILTY-LOAM INCEPTISOL IN NORTHERN ITALY UNDER DIFFERENT FERTILIZATION PRACTICES

    Directory of Open Access Journals (Sweden)

    Rosa Francaviglia

    2014-01-01

    Full Text Available We evaluated the efficiency of the RothC model to simulate Soil Organic Carbon (SOC dynamics after 12 years of organic and mineral fertilization practices in a study area located in northern Italy, on a silty-loam Inceptisol with a rotation including tomato, maize and alfalfa. The model performance was assessed by RMSE and EF coefficients. RothC simulated well observed SOC decreases in 71 samples (RMSE=7.42; EF=0.79, while performed with less accuracy when considering all samples (96 samples; RMSE=12.37; EF=0.58, due to the fact that the model failed in case of measured SOC increases (25 samples; RMSE=20.77; EF=-0.038. The model was used to forecast the SOC dynamics over a 50 year period under the same pedoclimatic conditions. Only clay contents >15% allowed to predict increasing levels of SOC respect to the starting values.

  1. Influence of N,K and CaSO4 on utilisation of sulfur by rice in red sandy loam soil

    International Nuclear Information System (INIS)

    Patnaik, M.C.; Sathe, Arun

    1993-01-01

    A greenhouse study with rice on red sandy loam soil showed that uptake of sulphur increased from both native as well as applied source with increase in the application of sulphur from 20-60 kg S ha -1 through gypsum. The grain yields were influenced by nitrogen application but there was only relative increase with the application of potassium and sulphur. There was positive effect of applied nitrogen and sulphur for the total sulphur removal by the rice crop. The per cent sulphur utilisation decreased with increase in sulphur application from 20-60 kg S ha -1 through gypsum but increased with increase in the application of nitrogen from 0-150 kg N ha -1 . Sulphur utilization by rice crop was more in potassium treated pots compared to that without its application. (author). 7 refs., 3 tabs

  2. Small proportions of silt linked to distinct and predictable differences in marine macrofaunal assemblages on the continental shelf of the Pacific Northwest

    Science.gov (United States)

    Henkel, S. K.; Politano, K. K.

    2017-07-01

    Increasing interest in offshore development has motivated intensified efforts to map the seafloor for marine spatial planning. However, surficial geologic maps do not accurately represent habitats for various species groups of concern. This study used a bottom-up approach to integrate macrofaunal densities and benthic conditions on the Pacific Northwest shelf to identify macrofaunal assemblages and associated habitat features. Benthic cores and water-column profiles were collected from 137 stations from 50 to 110 m depth. Analyses grouping stations based on both similar species abundances and benthic conditions resulted in six broad habitats. Within the sampled depth and latitudinal range, sediment characteristics were the primary structuring variable. A major break in assemblages was detected between sediment that had less than 1% silt/clay and those containing more than 1% silt/clay. Assemblages differed primarily in the bivalve species present and secondarily in polychaete species. Within the greater than and less than 1% silt/clay habitats, further discretization of assemblages was based mostly on differing abundances of characteristic bivalves and polychaetes associated with differing median grain sizes, which did not correspond to traditional definitions of fine or medium sand. These data show that a bottom-up methodology is necessary to discern habitats for macrofauna and that site-specific physical sampling is necessary to predict macrofaunal assemblage composition. However, if detailed sediment characteristics are known, macrofaunal assemblages may be predicted without time-intensive biological sampling and processing. These results also indicate that seemingly small sedimentary changes due to offshore installations may have measureable effects on the relative abundances and even the species composition of macrofauna.

  3. Function of a deltaic silt deposit as a repository and long-term source of sulfate and related weathering products in a glaciofluvial aquifer derived from organic-rich shale (North Dakota, USA)

    Science.gov (United States)

    Schuh, W. M.; Bottrell, S. H.

    2014-05-01

    A shallow unconfined glaciofluvial aquifer in North Dakota (USA) has largest groundwater sulfate concentrations near the bottom boundary. A deltaic silt layer underlying the aquifer, at >16 m, is the modern proximate sulfate source for the aquifer. The original sulfate source was pyrite in the organic-rich shale component of the aquifer and silt grain matrix. An oxidizing event occurred during which grain-matrix pyrite sulfur was oxidized to sulfate. Thereafter the silt served as a "conserving" layer, slowly feeding sulfate into the lower part of the aquifer and the underlying till. A method was developed for estimating the approximate initial sulfate concentration in the source layer and the redistribution time since the oxidizing event, using a semi-generic convection-dispersion model. The convection-dispersion model and a model for the evolution of modern sulfate δ 34S in silt-layer pore water from the initial grain-matrix pyrite δ 34S, both estimated that the oxidizing event occurred several thousand years ago, and was likely related to the dry conditions of the Hypsithermal Interval. The silt layer also serves as an arsenic source. Results indicate that deltaic silts derived from organic-rich shale parent materials in a glacial environment can provide long-term sources for sulfate and arsenic and possibly other related oxidative weathering products.

  4. The impacts of pyrolysis temperature and feedstock type on biochar properties and the effects of biochar application on the properties of a sandy loam

    Science.gov (United States)

    Aston, Steve; Doerr, Stefan; Street-Perrott, Alayne

    2013-04-01

    The production of biochar and its application to soil has the potential to make a significant contribution to climate change mitigation whilst simultaneously improving soil fertility, crop yield and soil water-holding capacity. Biochar is produced from various biomass feedstock materials at varying pyrolysis temperatures, but relatively little is known about how these parameters affect the properties of the resultant biochars and their impact on the properties of the soils to which they are subsequently applied. Salix viminalis, M. giganteus and Picea sitchensis feedstocks were chipped then sieved to 2 - 5 mm, oven dried to constant weight, then pyrolyzed at 350, 500, 600 and 800° C in a nitrogen-purged tube furnace. Biochar yields were measured by weighing the mass of each sample before and after pyrolysis. Biochar hydrophobicity was assessed by using a goniometer to measure water-droplet contact-angles. Cation-exchange-capacity (CEC) was measured using the ammonium acetate method. Biochars were also produced in a rotary kiln from softwood pellets at 400, 500, 600 and 700° C then ground to 0.4 - 1 mm and applied to a sandy loam at a rate of 50 g kg-1. Bulk densities of these soil-biochar mixtures were measured on a tapped, dry, basis. The water-holding-capacity (WHC) of each mixture was measured gravimetrically following saturation and free-draining. The filter paper method was used to assess how pyrolysis temperature influences the effect of biochar application on matric suction. For all feedstocks, large decreases in biochar yield were observed between the pyrolysis temperatures of 350° C and 500° C. For Salix viminalis and M. giganteus feedstocks, subsequent reductions in the yield with increasing pyrolysis temperature were much lower. There were significant differences in hydrophobicity between biochars produced from different biomass and mean biochar hydrophobicity decreased with increasing pyrolysis temperature for all feedstocks. Results for CEC and WHC

  5. Effect of the heat curing on strength development of self-compacting mortars containing calcined silt of dams and Ground Brick Waste

    Directory of Open Access Journals (Sweden)

    B. Safi

    2013-01-01

    Full Text Available The strength development of self-compacting mortars (SCM containing calcined silt (CS and ground brick waste (GWB was investigated. The variables are the nature of addition (CS and GWB in the binder and the heat curing at different temperatures (20 ºC and 60 ºC at 7 and 14 days of curing. Two temperatures 20 and 60 ºC were applied to samples with intermediate levels (depending on the drying method applied to precast for 18 hours in total. In this study, a Portland cement (CEMII, Calcined silt (750 ºC for 5 hours, ground waste brick, were used in the binders of SCM. The results show that the compressive strength to 14 days of mortars, increases with annealing (60 ºC compared to that measured at 20 ºC. Also, values of compressive strength of mortars at 14 days that are close to those obtained without 28 days curing treatment. Indeed, a strength gain of about 20.5% and 27.3% was obtained respectively for the SCM with GWB and the SCM with CS. However, a small change in mass recorded for both types of mortars.

  6. Effects of a novel poly (AA-co-AAm)/AlZnFe₂O₄/potassium humate superabsorbent hydrogel nanocomposite on water retention of sandy loam soil and wheat seedling growth.

    Science.gov (United States)

    Shahid, Shaukat Ali; Qidwai, Ansar Ahmad; Anwar, Farooq; Ullah, Inam; Rashid, Umer

    2012-10-25

    A novel poly(acrylic acid-co-acrylamide)AlZnFe₂O₄/potassium humate( )superabsorbent hydrogel nanocomposite (PHNC) was synthesized and its physical properties characterized using SEM, Energy Dispersive X-ray (EDX) and FTIR spectroscopic techniques. Air dried sandy loam soil was amended with 0.1 to 0.4 w/w% of PHNC to evaluate its soil moisture retention attributes. Effect of PHNC amendment on pH, electrical conductivity (EC), porosity, bulk density and hydraulic conductivity of sandy loam soil was also studied. The soil amendment with 0.1 to 0.4 w/w% of PHNC remarkably enhanced the moisture retention at field capacity as compared to the un-amended soils. Seed germination and seedling growth of wheat (Triticum aestivum L.) was considerably increased and a delay by 6-9 days in wilting of seedlings was observed in the soil amended with PHNC, resulting in improved wheat plant establishment and growth.

  7. Weeds of cereal stubble-fields on various soils in the Kielce region. P. II. Podzolic and brown soils developed from silt of water origin, loess and chernozem

    Directory of Open Access Journals (Sweden)

    Franciszek Pawłowski

    2013-12-01

    Full Text Available The weedy status of the cereal stubble-fields on a fertile soils (podzolic and brown developed from silt of water origin and loess as well as chemozem were asessed. The 243 phytosociological records, collected in 69 stands situated in 63 localities, were worked out. The species composition, number and constancy (S and indice of coverage (D of weed species are presented in the report. There were from 113 (podzolic loess to 142 (brown loess weed species on the edafic sites considered. The short-lived predominated among them (62-65%. The great floristic similarity was stated within the weed species occupied the investigated soils. The 88 species (including 27 perennial were common for the each of them. From 24 to 37 species dernonstrated high (V-III constancy degree, but only 5-12 along with high (over 200 indice of coverage.

  8. Amount of deposited by river silt Cs-137 brought to the river Arbuzynka with sewerage water from South Ukrainian Atomic Power Plant

    International Nuclear Information System (INIS)

    Vyintsukevich, N.V.; Tomyilyin, Yu.A.; Grigor'jeva, L.Yi.

    1996-01-01

    The peculiarities of radionuclide depositing in the silt of the river Arbuzynka in the place of discharge of sewerage water from South Ukrainian Atomic Power Plant have been studied. According to the finding of the observation, the main contribution to the total radioactivity of the sewerage water for the entire period of the plant operation was made by Cs-137. The greatest contamination of the river was observed in 1988 and 1993. It has been established that for the whole period of the plant operation two processes developed dynamically in the Arbuzynka, e.i. Cs-137 accumulation by the bottom deposits and its reserve receipt by the water. The process of accumulation was more dynamic

  9. Discovery of a landscape-wide drape of late-glacial aeolian silt in the western Northern Calcareous Alps (Austria): First results and implications

    Science.gov (United States)

    Gild, Charlotte; Geitner, Clemens; Sanders, Diethard

    2018-01-01

    Aeolian deposits record palaeoenvironmental conditions and may coin soil properties. Whereas periglacial loess is extensively investigated for 200 years, the study of the intramontane wind-blown deposits of the Alps has just stuttered along. Herein, we describe a drape of polymictic siliciclastic silt interpreted as an aeolian deposit that veneers extensive areas in the western Northern Calcareous Alps (NCA), from kames terraces near valley floors up to last-glacial nunataks. The NCA - part of the Eastern Alps mountain range - consist mainly of Triassic carbonate rocks; these are overlain by deposits of the Last Glacial Maximum (LGM) and its deglacial-paraglacial aftermath (e.g., glacial tills, fluvio-lacustrine successions, alluvial fans, scree slopes) - and a regional drape of polymictic silt newly described herein. The drape is typically a few decimeters in thickness and slightly modified by soil formation; it consists mainly of well-sorted silt of quartz, feldspars, phyllosilicates (muscovite, chlorite, biotite), amphiboles and, rarely, calcite or dolomite. The drape is unrelated to the substrate: it overlies carbonate bedrock and - in lateral continuity - abandoned deposystems such as colluvial slopes of redeposited till, kames, alluvial fans, scree slopes, and rock avalanche deposits. The drape was spotted from near the present valley floors up to LGM nunataks, over a vertical range of some 2000 m; it is also present in catchments of the NCA that were not overridden by far-travelled ice streams and that lack metamorphic rock fragments. Two OSL quartz ages of the drape from two distinct locations (18.77 ± 1.55 ka; 17.81 ± 1.68 ka) fall into the early Alpine late-glacial interval shortly after the collapse of pleniglacial ice streams; this fits with geological and geomorphological evidence, respectively, that the drape should be of early late-glacial age, and that it accumulated during a specific interval of time. In the NCA, localized minor deposition of

  10. Field application of a multi-frequency acoustic instrument to monitor sediment for silt erosion study in Pelton turbine in Himalayan region, India

    Science.gov (United States)

    Rai, A. K.; Kumar, A.; Hies, T.; Nguyen, H. H.

    2016-11-01

    High sediment load passing through hydropower components erodes the hydraulic components resulting in loss of efficiency, interruptions in power production and downtime for repair/maintenance, especially in Himalayan regions. The size and concentration of sediment play a major role in silt erosion. The traditional process of collecting samples manually to analyse in laboratory cannot suffice the need of monitoring temporal variation in sediment properties. In this study, a multi-frequency acoustic instrument was applied at desilting chamber to monitor sediment size and concentration entering the turbine. The sediment size and concentration entering the turbine were also measured with manual samples collected twice daily. The samples collected manually were analysed in laboratory with a laser diffraction instrument for size and concentration apart from analysis by drying and filtering methods for concentration. A conductivity probe was used to calculate total dissolved solids, which was further used in results from drying method to calculate suspended solid content of the samples. The acoustic instrument was found to provide sediment concentration values similar to drying and filtering methods. However, no good match was found between mean grain size from the acoustic method with the current status of development and laser diffraction method in the first field application presented here. The future versions of the software and significant sensitivity improvements of the ultrasonic transducers are expected to increase the accuracy in the obtained results. As the instrument is able to capture the concentration and in the future most likely more accurate mean grain size of the suspended sediments, its application for monitoring silt erosion in hydropower plant shall be highly useful.

  11. Physical-hydraulic properties of a sandy loam typic paleudalf soil under organic cultivation of 'montenegrina' mandarin (Citrus deliciosa Tenore¹

    Directory of Open Access Journals (Sweden)

    Caroline Valverde dos Santos

    2014-12-01

    Full Text Available Citrus plants are the most important fruit species in the world, with emphasis to oranges, mandarins and lemons. In Rio Grande do Sul, Brazil, most fruit production is found on small properties under organic cultivation. Soil compaction is one of the factors limiting production and due to the fixed row placement of this crop, compaction can arise in various manners in the interrows of the orchard. The aim of this study was to evaluate soil physical properties and water infiltration capacity in response to interrow management in an orchard of mandarin (Citrus deliciosa Tenore 'Montenegrina' under organic cultivation. Interrow management was performed through harrowing, logs in em "V", mowing, and cutting/knocking down plants with a knife roller. Soil physical properties were evaluated in the wheel tracks of the tractor (WT, between the wheel tracks (BWT, and in the area under the line projection of the canopy (CLP, with undisturbed soil samples collected in the 0.00-0.15, 0.15-0.30, 0.30-0.45, and 0.45-0.60 m layers, with four replicates. The soil water infiltration test was performed using the concentric cylinder method, with a maximum time of 90 min for each test. In general, soil analysis showed a variation in the physical-hydraulic properties of the Argissolo Vermelho-Amarelo distrófico arênico (sandy loam Typic Paleudalf in the three sampling sites in all layers, regardless of the management procedure in the interrows. Machinery traffic leads to heterogeneity in the soil physical-hydraulic properties in the interrows of the orchard. Soil porosity and bulk density are affected especially in the wheel tracks of the tractor (WT, which causes a reduction in the constant rate of infiltration and in the accumulated infiltration of water in this sampling site. The use of the disk harrow and mower leads to greater harmful effects on the soil, which can interfere with mandarin production.

  12. Major soil classes of the metropolitan region of Curitiba (PR, Brazil: I - mineralogical characterization of the sand, silt and clay fractions

    Directory of Open Access Journals (Sweden)

    Ana Christina Duarte Pires

    2007-03-01

    Full Text Available The aim of this work was to evaluate the mineralogical and chemical characteristics of most representative soils of the Region of Curitiba, Paraná State. Samples were collected at different depths. The results showed: (a the quartz was the only identified mineral at the silt and sand fractions. The dominant clay mineral was Kaolinite, with contents ranging from 676.7 to 820.8 g kg-1. The gibbsite was also an important constituent of the most weathered horizons and the hematite and goethite contents were low, mainly in the Histosol; (b at the C horizon of the Inceptisol, high intensity of vermiculite/smectite reflections were detected (X-ray diffraction, justifying the high capacity of expansion and contraction, normally showed for this soil horizon; (c was observed a good relation between pedogenetic degree and crystallographic mineral characteristics.Devido a grande importância dos minerais, notadamente aqueles da fração argila, sobre o planejamento de uso e sobre os impactos das atividades antrópicas, estudos detalhados da composição dos solos das regiões metropolitanas são imprescindíveis. Para avaliar as características mineralógicas e químicas de solos mais representativos da Região Metropolitana de Curitiba, estado do Paraná, foram coletadas amostras das classes Organossolo, Latossolo e Cambissolo, em diferentes profundidades. As frações areia, silte e argila foram estudadas por difratometria de Raios-X (DRX e a fração mais fina foi submetida a análise térmica e extrações químicas com oxalato de amônio (OA, ditionito-citrato-bicarbonato (DCB e solução de NaOH 5 mol L-1 fervente. As características cristalográficas da hematita (Hm, goethita (Gt, gibbsita (Gb e caulinita (Ct foram determinadas por DRX. Os resultados permitiram concluir que: (a o quartzo foi o único mineral identificado nas frações areia e silte. Na fração argila, verificou-se o predomínio de Ct, com teores variando de 661,7 a 820,8 g kg-1

  13. Efficiency of contour benches, filling-in and silting-up of a hillside reservoir in a semi-arid climate in Tunisia

    Science.gov (United States)

    Baccari, Noamen; Boussema, Mohamed Rached; Lamachère, Jean-Marie; Nasri, Slah

    2008-01-01

    The El Gouazine catchment area (18.1 km 2), located in semi-arid central Tunisia (average annual rainfall 350 mm), was equipped with total retention contour benches on 43% of its surface area between June 1996 and July 1997. In order to analyze the efficiency of these benches on the catchment area, different thematic maps (slope, lithology, land use, hydrographic network) were crossed using GIS with a map that located the benches and their breaks. Specific topographical surveys were also carried out on a series of 14 benches' in order to characterize the development of their holding capacities. To evaluate the impact of the contour bench installation on the catchment area, the change of liquid and solid inflow was measured at the catchment area outlet two years before and eight years after the bench installation. On-site surveys showed that contour bench dysfunction in the El Gouazine catchment area could not have been caused by man. However, three main physical causes could explain the dysfunction: placement of benches on gypsum clay soils, location of breaks on the hydrographic network, and slope greater than 25%. Topographic surveys showed that the benches initial holding capacity varied between 1 and 3 m 3 per linear metre for a construction standard fixed at 2.28 m 3. These surveys also showed that, nine years after their construction, the benches had lost 10 to 50% of their initial holding capacity. After installing benches in the El Gouazine catchment area, solid inflow was only reduced by 30%, whereas liquid inflow was reduced seven to eight times during a four-year period, which greatly limited the possibility of downstream irrigation. Annual runoff coefficients, at 4.5% before bench installation, were again at 5.1% in 2002-2003, and the silting-up rate was evaluated, in June 2005, as identical to its value before installation. Bench breakage and silting up of upstream canals explain these changes. The results of this study should serve to improve contour

  14. Moisture and temperature in a proppant-enveloped silt block of a recharge dam reservoir: Laboratory experiment and 1-D mathematical modelling

    Directory of Open Access Journals (Sweden)

    Anvar Kacimov

    2018-01-01

    Full Text Available Mosaic 3-D cascade of parallelepiped-shaped silt blocks, which sandwich sand- lled cracks, has been discovered in the eld and tested in lab experiments. Controlled wetting-drying of these blocks, collected from a dam reservoir, mimics field ponding-desiccation conditions of the topsoil layer subject to caustic solar radiation, high temperature and wind, typical in the Batinah region of Oman. In 1-D analytical modelling of a transient Richards’ equation for vertical evaporation, the method of small perturbations is applied, assuming that the relative permeability is Avery-anov’s 3.5-power function of the moisture content and capillary pressure is a given (measured function. A linearized advective dispersion equation is solved with respect to the second term in the series expansion of the moisture content as a function of spatial coordinates and time. For a single block of a nite thickness we solve a boundary value problem with a no- ow condition at the bottom and a constant moisture content at the surface. Preliminary comparisons with theta-, TDR- probes measuring the moisture content and temperature at several in-block points are made. Results corroborate that a 3-D heterogeneity of soil physical properties, in particular, horizontal and vertical capillary barriers emerging on the interfaces between silt and sand generate eco-niches with stored soil water compartments favourable for lush vegetation in desert conditions. Desiccation significantly increases the temperature in the blocks and re-wetting of the blocks reduces the daily average and peak temperatures, the latter by almost 15°C. This is important for planning irrigation in smartly designed soil substrates and sustainability of wild plants in the region where the top soil peak temperature in the study area exceeds 70°C in Summer but smartly structured soils maintain lash vegetation. Thee layer of dry top-blocks acts as a thermal insulator for the subjacent layers of wet blocks that

  15. The Effects of Land Configuration and Wood-Shavings Mulch on the Properties of a Sandy Loam Soil in Northeast Nigeria. 2. Changes in Physical Properties

    Directory of Open Access Journals (Sweden)

    Chiroma, AM.

    2006-01-01

    Full Text Available Mulching and ridge tillage are proven technologies for improving soil productivity in semi-arid regions. Yet data quantifying the combined influences of these practices are limited. Our objectives were to determine the changes in selected physical properties of a sandy loam after 4-years of annual tillage and wood-shavings mulching. The tillage and wood-shavings treatments consisted of: Flat bed (FB, Open ridge (OR, Tiedridge (TR, FBM, ORM and TRM were same as FB, OR and TR, respectively except that wood-shavings at a rate of 10 t/ha were surface applied ≈ 2 weeks after sowing each year to serve as both a mulch and an organic amendment. At the end of the trial in 2002, bulk density, penetration resistance, total porosity and soil water content from each of 0-0.075, 0.075-0.15 and 0.15-0.30 m depths were determined. Composite samples from the surface (0.075 and 0.075-0.15 m layers from 3 replicates of each treatment were also collected for the determination of wet aggregate stability and from 0-0.15 m and 0.15-0.30 m layers for determination of saturated hydraulic conductivity (Ksat. After 4 years of annual tillage and addition of woodshavings, soil bulk density and penetration resistance were consistently lower and total porosity higher in the FBM, ORM and TRM treatments than in the FB, OR and TR treatments. Penetration resistance in all treatments was strongly related to soil water content. A 'hoe pan' was established below 0.15 m depth beneath the furrows of the ridged treatments. This could be attributed to human traffic during field operations and ponding of water, which occurred in the furrows following heavy rains. Wet aggregate stability estimated as the proportion of aggregates of size > 0.25 mm (macro-aggregates in the 0-0.15 m layer were significantly (P< 0.05 higher under FBM, ORM and TRM than under FB, OR or TR treatments. Ksat was not influenced by either tillage or wood-shavings treatments but were higher for the mulched plots

  16. Peanut plant growth and yield as influenced by co-inoculation with Bradyrhizobium and some rhizo-microorganisms under sandy loam soil conditions

    Directory of Open Access Journals (Sweden)

    F.Sh.F. Badawi

    2011-06-01

    Full Text Available The ability of tested rhizomicrobial isolates (Serratia marcescens and Trichoderma harzianum along with a strain of root nodule bacteria (Bradyrhizobium spp. to exhibit some PGP-properties was evaluated in vitro conditions. The main PGP-properties, namely the ability to solubilize-P and production of IAA, as well as production of siderophores and HCN were examined. Additionally, field trials were conducted on sandy loam soil at El-Tahrir Province during two successive summer seasons to study the effect of co-inoculation with Bradyrhizobium either individually or together with S. marcescens and/or T. harzianum on nodulation, some plant growth characters, peanut yield and its yield components. The in vitro experiment revealed that all of the tested microorganisms were apparently able to trigger PGP-properties. Phosphate solubilization was the common feature of the employed microorganisms. However, T. harzianum appeared to be superior to other microorganisms, and Bradyrhizobium displayed the lowest capacity. The ability of the microorganisms to produce indole compounds showed that S. marcescens was more effective in IAA production and followed by Bradyrhizobium. Capacity of S. marcescens and T. harzianum to excrete ferric-specific ligands (siderophores and HCN was detected, while Bradyrhizobium failed to produce such compounds. Results of field trials showed that the uninoculated peanut had the least nodulation status, N2-ase activity and all vegetative growth characters in both studied seasons. Bacterization of peanut seeds with bradyrhizobia exerted considerable improvement in number and mass of root nodules, increased the rate of acetylene reduction and all growth characters in comparison to the uninoculated control. The synergy inoculation between bradyrhizobia and any of the tested microorganisms led to further increases of all mentioned characters and strengthened the stimulating effect of the bacterial inoculation. However, the promotive

  17. [Characteristics of N2, N2O, NO, CO2 and CH4 Emissions in Anaerobic Condition from Sandy Loam Paddy Soil].

    Science.gov (United States)

    Cao, Na; Wang, Rui; Liao, Ting-ting; Chen, Nuo; Zheng, Xun-hua; Yao, Zhi-sheng; Zhang, Hai; Butterbach-Bahl, Klaus

    2015-09-01

    Understanding the characteristics of the production of nitrogen gases (N2, N2O and NO), CO2 and CH4 in anaerobic paddy soils is not only a prerequisite for an improved mechanistic understanding of key microbial processes involved in the production of atmospheric greenhouse gases (GHG), but might also provide the basis for designing greenhouse gas mitigation strategies. Moreover, quantifying the composition fractions of denitrification gaseous products is of key importance for improving parameterization schemes of microbial processes in process-oriented models which are increasingly used for assessing soil GHG emissions at site and national scales. In our experiments we investigated two sandy loam soils from two paddy fields. The initial concentrations of soil nitrate and dissolved organic carbon (DOC) were set at approximately 50 mg.kg-1 and mg.kg-1, respectively, by adding a mixture solution of KNO3 and glucose. The emissions of N2, N2O NO, CO2 and CH4, as well as concentrations of carbon and nitrogen substrates for each soil sample were measured simultaneously, using a gas-flow-soil-core technique and a paralleling substrate monitoring system. The results showed that the accumulative emissions of N2, N2O and NO of the two soil samples for the entire incubation period were 6 - 8, 20, and 15 - 18 mg.kg-1, respectively. By measuring the cumulative emissions of denitrification gases (N, = N2 + N2O + NO) we were able to explain 95% to 98% of observed changes in s1ifr nilrate concentrations. The mass fractions of N2, N2O and NO emissions to Nt were approximately 15% -19%, 47% -49%, and 34% -36%, respectively. Thus, in our experiments N2O and NO were the main products of denitrification for the entire incubation period. However, as the temporal courses of hourly or daily production of the denitrification gases showed, NO production dominated and peaked firstly, and then N2O, before finally N2 became the dominant product. Our results show the high temporal dynamic of

  18. 1561-IJBCS-Article-Olivier Marc

    African Journals Online (AJOL)

    hp

    Mémoire de DEA, Université de. Ouagadougou, 122p. Bélem M, Guinko S. 1997. Exploitation et utilisation des végétaux de la forêt classée de Toessin. Province du Passoré, Burkina. Faso. Sciences et Techniques, Sciences. Naturelles, 23(1): 80-92. Bélem M. 2009. Les ligneux alimentaires des galeries forestières de la ...

  19. Tobias, Rudolf: Des Jona Sendung / Olivier Opdebeeck

    Index Scriptorium Estoniae

    Opdebeeck, Olivier

    1996-01-01

    Uuest heliplaadist "Tobias, Rudolf: Des Jona Sendung. Pille Lill (soprano), Urve Tauts (mezzo-soprano), Peter Svensson (tenor), Raimo Laukka (baryton), Mati Palm (basse); Choeur d'Oratorio, Choeur de chambre Philharmonique d'Estonie, Choeur de garcons de Tallinn, Orchestre Symphonique d'Etat d'Estonie, Neeme Järvi" BIS CD-731/732, distribution Arcade 8000 716 (2 CD: 290F). TT: 1h 54'13"

  20. 1612-IJBCS-Article- Luc Olivier

    African Journals Online (AJOL)

    hp

    douce, l'air pur et un climat relativement stable, sont dégradés ou utilisés de manière non durable (UN, 2005) .... l'année 2003 (année humide), alors que la valeur minimale 755,2 mm est enregistrée pendant l'année 2005 qui ... relative de l'air est élevée. Le bassin en étude présente des sols très variés, répartis en fonction ...

  1. 2531-IJBCS-Article-Etchian Olivier Assoi

    African Journals Online (AJOL)

    hp

    Herklots, 1851 (Crustacea, Brachyura, Gecarcinidae) from the estuarine region of the Comoe ... (or 'land-dwelling' crabs), based on the terrestrial habits shown by adults ...... composition, growth pattern and feeding habits of the blue crab, ...

  2. Stormwater quality performance of a macro-pervious pavement car park installation equipped with channel drain based oil and silt retention devices.

    Science.gov (United States)

    Newman, Alan Paul; Aitken, Douglas; Antizar-Ladislao, Blanca

    2013-12-15

    This paper reports the results of a two year field monitoring exercise intended to investigate the pollution abatement capabilities of a novel system which offers an alternative to the, now well established, pervious pavement system as a source control device for stormwater management. The aim of this study was to determine the effectiveness of a live installation of a macro-pervious pavement system (MPPS) (operated as a visitors' car park at a prison in Central Scotland) in retaining and treating a range of pollutants which originate from automobile use or become concentrated on the parking surface from the wider environment. The MPPS is a sub-class of pervious pavement system where the vast majority of the surface is impermeable. It directs stormwater into a pervious sub surface storage/attenuation zone through a series of distinct infiltration points fast enough to prevent flooding during the design storm. In the particular system studied here the infiltration points consist of a network of oil/silt separation devices with extensive further pollutant retention/degradation provided during the passage of stormwater through the sub surface zone. Approximately 12 months after the car park was completed a sampling regime was instigated in which grab samples were collected at intervals from each of the three sub catchments whilst, simultaneously, samples were collected directly from the, pollutant retaining, infiltration devices. Through investigation of samples collected at the upstream end of the system, the retention of significant amounts of hydrocarbons and heavy metals in the initial collection devices has been illustrated and the analysis of effluent samples collected at the outlet points indicate that the system is capable of producing effluent which is of a standard comparable to that expected from a traditional pervious pavement system and is acceptable for direct release into a surface water receptor. The system offers the opportunity to accrue the benefits

  3. Vertical hydraulic conductivity of a clayey-silt aquitard: accelerated fluid flow in a centrifuge permeameter compared with in situ conditions

    Science.gov (United States)

    Timms, W. A.; Crane, R.; Anderson, D. J.; Bouzalakos, S.; Whelan, M.; McGeeney, D.; Rahman, P. F.; Guinea, A.; Acworth, R. I.

    2014-03-01

    Evaluating the possibility of leakage through low permeability geological strata is critically important for sustainable water supplies, extraction of fuels from strata such as coal beds, and confinement of waste within the earth. Characterizing low or negligible flow rates and transport of solutes can require impractically long periods of field or laboratory testing, but is necessary for evaluations over regional areas and over multi-decadal timescales. The current work reports a custom designed centrifuge permeameter (CP) system, which can provide relatively rapid and reliable hydraulic conductivity (K) measurement compared to column permeameter tests at standard gravity (1g). Linear fluid velocity through a low K porous sample is linearly related to g-level during a CP flight unless consolidation or geochemical reactions occur. The CP module is designed to fit within a standard 2 m diameter, geotechnical centrifuge with a capacity for sample dimensions of 30 to 100 mm diameter and 30 to 200 mm in length. At maximum RPM the resultant centrifugal force is equivalent to 550g at base of sample or a total stress of ~2 MPa. K is calculated by measuring influent and effluent volumes. A custom designed mounting system allows minimal disturbance of drill core samples and a centrifugal force that represents realistic in situ stress conditions is applied. Formation fluids were used as influent to limit any shrink-swell phenomena which may alter the resultant K value. Vertical hydraulic conductivity (Kv) results from CP testing of core from the sites in the same clayey silt formation varied (10-7 to 10-9 m s-1, n = 14) but higher than 1g column permeameter tests of adjacent core using deionized water (10-9 to 10-11 m s-1, n = 7). Results at one site were similar to in situ Kv values (3 × 10-9 m s-1) from pore pressure responses within a 30 m clayey sequence in a homogenous area of the formation. Kv sensitivity to sample heterogeneity was observed, and anomalous flow via

  4. VARIABILIDADE ESPACIAL DE ARGILA, SILTE E ATRIBUTOS QUÍMICOS EM UMA PARCELA EXPERIMENTAL DE UM LATOSSOLO ROXO DE CAMPINAS (SP

    Directory of Open Access Journals (Sweden)

    SIDNEY ROSA VIEIRA

    1997-01-01

    Full Text Available A grande maioria dos ensaios de manejo e fertilidade do solo utiliza o método de delineamentos experimentais, segundo o qual as observações devem ser independentes umas das outras e as parcelas experimentais, uniformes quanto aos atributos estudados. A hipótese de independência entre as amostras apenas pode ser satisfeita e verificada na prática, se a amostragem contiver informações geográficas, como, por exemplo, as coordenadas com referências a um eixo arbitrário para possibilitar análises da geoestatística. O objetivo deste trabalho foi estudar a variabilidade espacial de alguns atributos químicos e granulométricos do solo dentro de uma parcela experimental e mostrar o uso da geoestatística para analisar os dados. O campo estudado localiza-se no Centro Experimental de Campinas do Instituto Agronômico, Campinas (SP, em um latossolo roxo distrófico sob preparo convencional nos últimos dez anos. Marcou-se uma parcela de 30 m por 30 m a cada 5 m em duas direções, resultando em um reticulado quadrado de 49 pontos de amostragem. Em cada ponto, coletaram-se amostras de solo das camadas 0-25 cm e 25-50 cm de profundidade, as quais foram levadas ao laboratório, secas ao ar, peneiradas em uma malha de 2 mm e submetidas às análises granulométricas e químicas de rotina para obter teor de argila, teor de silte, delta pH, soma de bases (S, capacidade de troca catiônica (CTC e saturação por bases (V%. Para a análise de variabilidade espacial, utilizou-se a geoestatística. Os coeficientes de variação encontrados são mais altos na camada 0-25 cm do que na 25-50 cm, provavelmente devido à região de maior alteração com cultivo. Foi encontrada dependência espacial para todos os atributos analisados para a camada 0-25 cm, e dependência fraca para a camada 25-50 cm. Considerando que o campo engloba apenas uma área de 30 m por 30 m, conclui-se que a variabilidade encontrada para os atributos químicos do solo foi grande e

  5. Radiological aspects of choice of a system of cultivation of sod-podzolic sandy loam soils with different degree of humidity on lands of Mogilev region contaminated with 137Cs

    International Nuclear Information System (INIS)

    Lazarevich, S.S.; Ermolenko, A.V.; Shapsheeva, T.P.

    2010-01-01

    In the conditions of the Republic of Belarus there were presented data about the influence of technological factors on entry of 137Cs into plant products (grain and green mass). In course of the study there were analyzed the following variants of soil cultivation: moldboard plowing; subsurface chisel soil tillage; subsurface surface soil tillage; minimal tillage. There were presented data on specific activity of 137Cs in plant product samples of oat (Avena sativa) grain; field pea (Pisum arvense L.) and oat mixture grain and green mass; wheat (Triticum aestivum) grain. There were determined the main principles of influence of cultivation systems of sod-podzolic sandy loam soil with different degree of humidity on transition of 137Cs into plants depending on the degree of soil and crop humidity. On the automorphic soil there was revealed a tendency of increased transition of 137Cs into grain and green mass after application of subsurface surface soil tillage system

  6. Field-measured, hourly soil water evaporation stages in relation to reference evapotranspiration rate and soil to air temperature ratio

    Science.gov (United States)

    Soil water evaporation takes critical water supplies away from crops, especially in areas where both rainfall and irrigation water are limited. This study measured bare soil water evaporation from clay loam, silt loam, sandy loam, and fine sand soils. It found that on average almost half of the ir...

  7. Environmental Assessment, Repair of the Dam at Non-Potable Reservoir #1, United States Air Force Academy, Colorado

    Science.gov (United States)

    2015-08-01

    expected and are not analyzed further in this EA. Utilities. The electrical, natural gas, water, and sanitary sewer requirements of the Proposed...therefore, no increase in utility usage or sanitary and solid waste generation would occur. Utility connections that run alongside the existing dam...for evaluation of the soils suitability for native revegetation. An acceptable topsoil shall have a loam, sandy loam, clay loam, or silt loam texture

  8. Uus silt turul - clean label / Gunnel Koba

    Index Scriptorium Estoniae

    Koba, Gunnel

    2013-01-01

    Suurbritanniast alguse saanud clean labeli toiduainete märgis annab tarbijale kindlustunde, et tegemist on võimalikult puhta lihtsa ja arusaadava koostisega tootega. Samas pole märgisel ametlikku definitsiooni ning pole välistatud, et toiduaine koostises ei ole ka mõni e-aine

  9. Shear strength of clay and silt embankments.

    Science.gov (United States)

    2009-09-01

    Highway embankment is one of the most common large-scale geotechnical facilities constructed in Ohio. In the past, the design of these embankments was largely based on soil shear strength properties that had been estimated from previously published e...

  10. Nature, Capitalism, and the Future of Humankind | Olivier | South ...

    African Journals Online (AJOL)

    This paper addresses the question regarding the relation between capitalism and nature, on the one hand, and that of the continued existence of life, including humankind, on earth in light of the disturbing evidence that has emerged since the early 1970s, concerning massive environmental degradation, on the other.

  11. Tests for predicting endurance kayak performance | Olivier | South ...

    African Journals Online (AJOL)

    Methods : The following variables were measured on 23 competitive endurance kayakers, who provided written informed consent : Arm crank VO2 peak; 1 minute dips; armspan; modified sit-and-reach; grip strength; body mass; height. These were selected on the basis of their being identified as possibly contributing to ...

  12. Pharmacognostic studies of insect gall of Quercus infectoria Olivier (Fagaceae

    Directory of Open Access Journals (Sweden)

    Savitri Shrestha

    2014-01-01

    Conclusions: The results of the present study serve as a valuable source of information and provide suitable standards for identification of this medicinally important plant drug material for future investigations and applications.

  13. Postgraduate supervision: for better or for worse? | Olivier | South ...

    African Journals Online (AJOL)

    No Abstract. South African Journal of Higher Education Vol. 21 (8) 2007: pp. 1126-1140. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's ...

  14. Field performance of three real-time moisture sensors in sandy loam and clay loam soils

    Science.gov (United States)

    The study was conducted to evaluate HydraProbe (HyP), Campbell Time Domain Reflectometry (TDR) and Watermarks (WM) moisture sensors for their ability to estimate water content based on calibrated neutron probe measurements. The three sensors were in-situ tested under natural weather conditions over ...

  15. Soil physical effects on longleaf pine performance in the West Gulf Coastal Plain

    Science.gov (United States)

    Mary Anne S. Sayer; James D. Haywood; Shi-Jean Susana Sung

    2015-01-01

    We summarize 8 years of soil physical property responses to herbicide manipulation of the understory in two young longleaf pine stands growing on either Ruston fine sandy loam or Beauregard silt loam soils. We also describe relationships between pine sapling vigor and the soil physical environment across a 3-year period on the Ruston soil and a 2-year period on the...

  16. PHYSICOCHEMICAL PROPERTIES AS PREDICTORS OF ORGANIC CHEMICAL EFFECTS ON SOIL MICROBIAL RESPIRATION

    Science.gov (United States)

    Structure-activity analysis was used to evaluate the effects of 19 hazardous organic chemicals on microbial respiration in two slightly acidic soils (a Captina silt loam from Roane County Tennessee, and a McLaurin sandy loam from Stone County, Mississippi), both low in organic ca...

  17. The application of radioactive isotopes to the study of motion of silt and pebbles in the rivers and in the sea; Application des isotopes radioactifs a l'etude des mouvements des sediments et des galets dans les cours d'eau et en mer

    Energy Technology Data Exchange (ETDEWEB)

    Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

    1959-07-01

    The application of radioactive tracers to the study of sediments drift has received considerable attention since 1954 in various countries. A comparative review is made of a number of techniques of labelling, immersing and detecting silts, sands, and pebbles. The influence of the burying of the active material is emphasized. The different experiments which have been so far carried out are described. (author) [French] L'application des traceurs radioactifs a l'etude des deplacements de sediments a fait depuis 1954 l'objet de travaux nombreux dans divers pays. On passe en revue et on compare differentes techniques de marquage, d'immersion et de detection des vases, sables et galets; on insiste sur l'influence de l'enfouissement du materiau actif. On decrit les differentes experiences effectuees jusqu'a ce jour. (auteur)

  18. Passive Microwave Observation of Soil Water Infiltration

    Science.gov (United States)

    Jackson, Thomas J.; Schmugge, Thomas J.; Rawls, Walter J.; ONeill, Peggy E.; Parlange, Marc B.

    1997-01-01

    Infiltration is a time varying process of water entry into soil. Experiments were conducted here using truck based microwave radiometers to observe small plots during and following sprinkler irrigation. Experiments were conducted on a sandy loam soil in 1994 and a silt loam in 1995. Sandy loam soils typically have higher infiltration capabilities than clays. For the sandy loam the observed brightness temperature (TB) quickly reached a nominally constant value during irrigation. When the irrigation was stopped the TB began to increase as drainage took place. The irrigation rates in 1995 with the silt loam soil exceeded the saturated conductivity of the soil. During irrigation the TB values exhibited a pattern that suggests the occurrence of coherent reflection, a rarely observed phenomena under natural conditions. These results suggested the existence of a sharp dielectric boundary (wet over dry soil) that was increasing in depth with time.

  19. Effect of Tractor Forward Speed on Sandy Loam Soil Physical ...

    African Journals Online (AJOL)

    Results indicate significant differences in soil physical conditions arising from different levels of tractor forward speed. A forward speed of approximately 7km/h resulted in appreciable amelioration of soil structure as reflected in improvements in the soil strength properties and maximum reduction in clod mean weight ...

  20. Laboratory Study of the Influence of Substrate Type and Temperature on the Exploratory Tunneling by Formosan Subterranean Termite

    Directory of Open Access Journals (Sweden)

    Bal K. Gautam

    2012-06-01

    Full Text Available Using two-dimensional foraging arenas, laboratory tests were conducted to investigate the effect of soil type, soil moisture level and ambient temperature on the exploratory tunneling by Coptotermes formosanus Shiraki. In choice arenas consisting of two substrate types having two moisture levels each, and conducted at a constant temperature of 22 °C, a significantly greater proportion of termites aggregated in sand than in sandy loam. Similarly, the length of excavated tunnels was also increased in sand. In a given substrate, termite aggregation or tunnel length did not differ between 5% and 15% moisture levels. In no-choice tests, where three different substrates (sand, sandy loam and silt loam were tested at two temperatures (22 °C and 28 °C, excavations were significantly greater in sand than either sandy loam or silt loam at 22 °C. Fewer primary tunnels were constructed in sandy loam than in sand and fewer branched tunnels than either in sand or silt loam. No significant difference in either tunnel length or number of primary or branched tunnels was found between these two temperatures.

  1. Distribución de la porosidad de un suelo franco arcilloso (alfisol en condiciones semiáridas después de 15 años bajo siembra directa Soil porosity distribution of a clay loam soil (alfisol in semi-arid conditions after 15 years under direct drilling

    Directory of Open Access Journals (Sweden)

    Cecilia Isabel Cerisola

    2005-12-01

    Full Text Available A partir de un estudio más amplio sobre evolución de las propiedades físicas de un suelo sometido a tres sistemas de labranza, se realizó, en dos campañas consecutivas, un seguimiento de la distribución de la porosidad del suelo según su origen, en parcelas cultivadas bajo siembra directa continua durante 15 años. En el ensayo se consideró un trayecto de 2 metros de longitud, perpendicular a la dirección de las labores, donde se realizaron mediciones de densidad aparente seca y contenido de humedad. El cultivo extensivo de secano (cereal, en cada una de las dos campañas, fue cebada de ciclo corto y de ciclo largo. El calendario de la toma de datos de las variables medidas se fijó en 5 fechas por campaña. La porosidad estructural del suelo, debida principalmente a la alternancia de ciclos de humectación - desecación, fue calculada cada 5 cm y hasta 35 cm de profundidad. Este proceso de fisuración natural resulta suficiente para asegurar un buen drenaje y facilitar el desarrollo radicular de las plantas, siempre y cuando el contenido de humedad se mantenga dentro de la capacidad de retención de agua.On a long-term essay under direct drilling, the evolution of the physical properties of a clay loam soil, such as distribution by origin of soil porosity, has been assessed during two growing seasons. The cereal crops in each growing seasons were spring barley and winter barley, respectively. Soil physical properties were measured on a 2 m length transect located in a perpendicular line to the direction of vehicular traffic for field operations. Five sampling opportunities, within crop cycle, were used to measure the variables. Structural soil porosity, due principally to shrinkage and swelling cycles, was assessed in the 0 to 35 cm depth soil profile. This natural process seemed to be sufficient to guarantee good drainage and normal crop development, unless in the moisture content range included in field capacity.

  2. Physical Modelling of Silt in Relation to Offshore Wind Turbines

    DEFF Research Database (Denmark)

    Holmsgaard, Rikke

    precisely so that the competitiveness of offshore wind turbines can be improved. Carrying out in situ tests offshore is very expensive. Therefore, all experiment regarding this project is conducted onshore. A field in Dronninglund was found useful for this purpose since the subsoil at the field mainly......Offshore wind energy is a sustainable form of energy that can help reduce the emission of greenhouse gases and increase the share of renewable energy. In order to ensure that offshore wind energy can continue to be a competitive source of energy compared to other types of renewable energy...... consists of silty soil and the water table is situated just below the surface so the field is comparable to offshore conditions. In connection with the project, CPT and SCPT (Seismic Cone Penetration Test) were conducted in the field, just like large soil samples were collected with the purpose of carrying...

  3. A Case Study On Pile Relaxation In Dilative Silts

    Science.gov (United States)

    2011-12-20

    2 Table 2-1 Correlation of Uncorrected SPT N -Value with Total Unit Weight and Friction Angle (Kulhawy and Mayne, 1990...Effective internal friction angle. N = Uncorrected SPT blow count. σ’v = Effective vertical stress. cn = Overburden correction factor...shear strength of the soil. The unit weight of a soil can be determined from correlations to SPT N values, as shown in Table 2.1. 10

  4. Shear strength of clay and silt embankments : executive summary report.

    Science.gov (United States)

    2009-11-01

    Highway embankments constitute some of the most common geotechnical facilities being constructed by highway and transportation agencies. The design, construction, and field performance of these embankments are great importance to federal and state tr...

  5. Late Quaternary fine silt deposits of Jammu, NW Himalaya: Genesis ...

    Indian Academy of Sciences (India)

    ... of Jammu suggest fluvial environment of the deposits wherein the water budget fluctuated. ... the probable source for desert 'loess' of Pakistan. (Rendell et al 1989). ...... the velocity of water is diminished due to loss of flow competence and.

  6. Toxicity of Fipronil in Mississippi Soil Types Against Reticulitermes flavipes (Isoptera: Rhinotermitidae)

    Science.gov (United States)

    J. E. Mulrooney; P. D. Gerard

    2007-01-01

    Three soils (a silt loam, loamy sand, sandy loam) found in Mississippi and pure silica sand were treated with fipronil and bioassayed using eastern subterranean termites, Reticulitermes flavipes. Soils were treated with aqueous solutions of Termidor (fipronil) at concentrations of 0, 0.12, 0.25,2.5, 5.0 and 20.0 ppm (wt AI: wt soil) that brought the soils to 15%...

  7. Environmental Assessment Newport Research Facility Irish Hill

    Science.gov (United States)

    2011-09-12

    Classification Symbol Burdett silt loam, 3 to 8 percent BuB Not Hydric Prime Farmland if Drained slopes Honeoye and Lansing silt loams, Hre Not...Part USDA - llap unit symbol BuB ~ CsB HrE HsD HIB HtC LnC LnD McB MIS ~ MoB I MoD NaB NaC NaD I 1R0 •ShF llap unit Mille Rating

  8. Escarificação mecânica e biológica para a redução da compactação em argissolo franco-arenoso sob plantio direto Mechanical and biological chiseling to reduce compaction of a sandy loam alfisol under no-tillage

    Directory of Open Access Journals (Sweden)

    S. L. Abreu

    2004-06-01

    saturado, em médio prazo, a "escarificação biológica" (CM-crot mostrou-se mais eficaz na ruptura da camada compactada e estabelecimento de poros condutores de água do que a escarificação mecânica (Esc-soja do solo. Em contrapartida, se o indicador for a RP, o resultado é inverso. Assim, a propriedade hídrica ou mecânica do solo a ser usada como indicadora para a avaliação da eficácia da ruptura da camada compactada do solo depende do processo físico priorizado: a infiltração e redistribuição de água ou a penetração e crescimento de raízes.Soil management alters the physical soil properties and changes the soil air, water, and solute dynamics. Physical soil properties as affected by conservationist soil management systems were studied in a sandy loam Typic Hapludalf. The treatments were established on a soil that has been under no-tillage for 10 years, and consisted of: no-tillage soybeans, chisel tillage soybeans, reduced tillage Crotalaria, and bare soil without tillage. The evaluated soil properties were soil penetration resistance, bulk density, porosity, pore size distribution, saturated and unsaturated hydraulic conductivity, water infiltration using concentric rings or natural rainfall, variation of the volumetric soil moisture throughout the cropping cycle, and water retention curve. Soil penetration resistance (PR was highest at 0.075 m and 0.175 m depth in no-tillage and chiseled soil, respectively. Soil subsurface mobilization with chiseling and surface mobilization due to disking and sowing did not influence the bulk density (BD after the crop harvest. No-till soil under soybean crop had greater macroporosity than reduced tillage crotalaria and bare soil at 0.02 to 0.05 m depth, resulting in a greater saturated hydraulic conductivity and lower water retention during periods of low water availability. Among the analyzed soil physical-mechanical properties, PR seemed to be more sensitive to detect soil compaction than BD or porosities

  9. Migration of 137Cs and 90Sr in undisturbed soil profiles under controlled and close-to-real conditions

    International Nuclear Information System (INIS)

    Forsberg, S.; Rosen, K.; Fernandez, V.; Juhan, H.

    2000-01-01

    Migration of 137 Cs and 90 Sr in undisturbed soil was studied in large lysimeters three and four years after contamination, as part of a larger European project studying radionuclide soil-plant interactions. The lysimeters were installed in greenhouses with climate control and contaminated with radionuclides in an aerosol mixture, simulating fallout from a nuclear accident. The soil types studied were loam, silt loam, sandy loam and loamy sand. The soils were sampled to 30-40 cm depth in 1997 and 1998. The total deposition of 137 Cs ranged from 24 to 45 MBq/m 2 , and of 90 Sr from 23 to 52 MBq/m 2 . It was shown that migration of 137 Cs was fastest in sandy loam, and of 90 Sr fastest in sandy loam and loam. The slowest migration of both nuclides was found in loamy sand. Retention within the upper 5 cm was 60% for both 137 Cs and 90 Sr in sandy loam, while in loamy sand it was 97 and 96%, respectively. In 1998, migration rates, calculated as radionuclide weighted median depth (migration centre) divided by time since deposition were 1.1 cm/year for both 137 Cs and 90 Sr in sandy loam, 0.8 and 1.0 cm/year, respectively, in loam, 0.6 and 0.8 cm/year in silt loam, and 0.4 and 0.6 cm/year for 137 Cs and 90 Sr, respectively, in loamy sand. A distinction is made between short-term migration, caused by events soon after deposition and less affected by soil type, and long-term migration, more affected by e.g. soil texture. Three to four years after deposition, effects of short-term migration is still dominant in the studied soils

  10. Effect of Injecting Hydrogen Peroxide into Heavy Clay Loam Soil on Plant Water Status, NET CO2 Assimilation, Biomass, and Vascular Anatomy of Avocado Trees Efecto de la Inyección de Peróxido de Hidrógeno en Suelo Franco Arcilloso Pesado, sobre el Estado Hídrico, Asimilación Neta de CO2, Biomasa y Anatomía Vascular de Paltos

    Directory of Open Access Journals (Sweden)

    Pilar M Gil M

    2009-03-01

    Full Text Available In Chile, avocado (Persea americana Mill. orchards are often located in poorly drained, low-oxygen soils, situation which limits fruit production and quality. The objective of this study was to evaluate the effect of injecting soil with hydrogen peroxide (H2O2 as a source of molecular oxygen, on plant water status, net CO2 assimilation, biomass and anatomy of avocado trees set in clay loam soil with water content maintained at field capacity. Three-year-old ‘Hass’ avocado trees were planted outdoors in containers filled with heavy loam clay soil with moisture content sustained at field capacity. Plants were divided into two treatments, (a H2O2 injected into the soil through subsurface drip irrigation and (b soil with no H2O2 added (control. Stem and root vascular anatomical characteristics were determined for plants in each treatment in addition to physical soil characteristics, net CO2 assimilation (A, transpiration (T, stomatal conductance (gs, stem water potential (SWP, shoot and root biomass, water use efficiency (plant biomass per water applied [WUEb]. Injecting H2O2 into the soil significantly increased the biomass of the aerial portions of the plant and WUEb, but had no significant effect on measured A, T, gs, or SWP. Xylem vessel diameter and xylem/phloem ratio tended to be greater for trees in soil injected with H2O2 than for controls. The increased biomass of the aerial portions of plants in treated soil indicates that injecting H2O2 into heavy loam clay soils may be a useful management tool in poorly aerated soil.En Chile, los huertos de palto (Persea americana Mill. se ubican comúnmente en suelos pobremente drenados con bajo contenido de oxígeno, lo que limita producción y calidad de fruta. El objetivo de este estudio fue evaluar el efecto de la inyección de peróxido de hidrógeno (H2O2 al suelo como fuente de O2, sobre el estado hídrico, asimilación de CO2, biomasa y anatomía de paltos en suelo franco arcilloso con

  11. Olivier Messiaen's quartet for the end of time, secret of form: Movement VI

    Directory of Open Access Journals (Sweden)

    Maksimović Svetlana

    2005-01-01

    Full Text Available Knowing that Messiaen's early period, especially The Quartet for the End of Time, got so many written comments and discussions and from renowned critics, musicologists and composers it is hard to believe that anything different could possibly come out about the structure, form or concept in his work. Still, another look at these works would be valuable, since the concept of form is far from explored. The focal point of this text is the sixth movement from the Quartet and its concept of form. It unveils the relation between Messiaen's music ideas and the ancient Greek tragedy and the depth of the influence that Greek art had on his concept of form. The influence goes as far as the "suggestion of ring composition".

  12. 159 Évaluation de l'activité biologique des feuilles de l'olivier ...

    African Journals Online (AJOL)

    PC

    naturelles, nous avons essayé dans cette étude de contribuer à la connaissance de certains effets biologiques des feuilles ... alternative aux médicaments conventionnels. En Algérie, les plantes ... comparaison de deux moyennes de deux séries de mesure est réalisée grâce au test 't' de Student-Fisher. 2-5. Evaluation de ...

  13. État et perspectives de lutte contre Sitotroga cerealella (Olivier, 1789 ...

    African Journals Online (AJOL)

    Plusieurs chercheurs se sont intéressés, dans le cadre des luttes physiques, aux irradiations ionisantes provenant de source de rayons gamma du cobalt 60 et des variétés de céréales résistantes dans le cas du riz, du blé ou de maïs. Aussi, des parasites, pathogènes ou prédateurs (Trichogramma spp, Blattisocius tarsalis, ...

  14. Euroopa riigijuhid süüdistavad EL-i asjata / Olivier Blanchard

    Index Scriptorium Estoniae

    Blanchard, Olivier

    2005-01-01

    Ilmunud ka: Molodjozh Estonii 21. juuni lk. 13. Massachusettsi tehnoloogiainstituudi majandusprofessori analüüs Euroopa Liidu olukorrast pärast Prantsusmaa ja Hollandi rahvahääletust ning Euroopa Liidu tippkohtumist

  15. The Prevalence of Salmonella and Staphylococcus Aureus in Industrial Olivier Salad in Yazd in 2013

    Directory of Open Access Journals (Sweden)

    F Kaseb

    2015-09-01

    Conclusion: Salmonella and Staphylococcus aureus have particular importance in food contaminations.Lack of hygiene during production, contamination of raw materials and elevation of storage temperature are important factors for the increased contamination. So control and monitoring of food centers by the health units is obvious.

  16. Identification of pigmented Serratia marcescens symbiotically associated with Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae).

    Science.gov (United States)

    Scrascia, Maria; Pazzani, Carlo; Valentini, Franco; Oliva, Marta; Russo, Valentina; D'Addabbo, Pietro; Porcelli, Francesco

    2016-10-01

    To characterize red pigment-producing bacteria (RPPB) regularly released during oviposition by red palm weevil (RPW), RPPB were recovered from eggs deposited in apples supplied as substrate for oviposition. The presence of RPPB was also detected from gut, the reproductive apparatus of dissected adult and virgin insects and from pupal cases collected within infested palms. RPPB were also identified all along the tissue of these palms. Analysis of the 16S rDNA, gyrB, rpoB, recA, and groEL sequences assigned RPPB to the species Serratia marcescens. RPPB exhibited an antimicrobial activity assessed by the agar well diffusion method against a number of gram-positive and gram-negative bacteria. In this study, we first report the identification of a red pigment-producing S. marcescens as extracellular symbiont of RPW. Route of transmission, detection within different organs, and a wide spread along the infested palm tissue, suggested S. marcescens is present as extracellular symbiont in different developmental stages of the RPW. Additionally, the antimicrobial activity exhibited versus Bacillus spp., Paenibacillus spp., and Lysinibacillus spp., reported as insect pathogens and potential candidates for biocontrol agents, could ascribe for S. marcescens a potential protective role. © 2016 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  17. Sociogenetic structure of Polistes (Aphanilopterus versicolor Olivier, 1791 colonies (Hymenoptera, Vespidae, Polistini

    Directory of Open Access Journals (Sweden)

    Keize Nagamati Junior

    2010-01-01

    Full Text Available The observation of two distinct, well-defined oviposition areas in nests of the primitively eusocial wasp Polistes versicolor suggests the presence of multiple egg-layers and territorial behaviors. Electrophoretic analysis of enzyme loci in pupae from 35 colonies revealed an average observed heterozygosity of 0.10 and the existence of private polymorphisms, thereby indicating a low dispersion in this species. No evidence of diploid males was found. Phenotypic segregation analysis revealed the presence of more than one egg-laying female in 15 out of 35 colonies, as well as spatially preferential oviposition in 2 out of 13 nests, with distinct oviposition areas. Genetic relatedness estimates for brood were lower than expected for haplodiploid species under monogynous conditions (r = 0.75 for female broods and r = 0.5 for male in 4 of those 13 nests, thereby inferring complex sociogenetic structuring in Polistes versicolor colonies.

  18. Die sin van pyn. (The meaning of pain) | Olivier | South African ...

    African Journals Online (AJOL)

    The second problem, which I focus on, consists in the attempt to offer a description of the physiological basis (which I call embodiment) of mental pain, which does not reduce the mental to the physical. I thereby present the thesis that pain can be understood either as the body's revolt against the mind or the mind's revolt ...

  19. État et perspectives de lutte contre Sitotroga cerealella (Olivier, 1789 ...

    African Journals Online (AJOL)

    SARAH

    31 juil. 2014 ... Conclusion : Essential oils from aromatic plants of Benin could effectively control populations of S. cerealella in the conservation of ...... insecticidal, larvicidal and ovicidal effects on. Callosobruchus maculatus of essential oils of. Cymbopogon giganteus and of Xylopia aethiopica. SCIENTIFIC STUDY &.

  20. Evaluation of employee commitment as an imperative for business success / Esti Olivier

    OpenAIRE

    Olivier, Esti

    2011-01-01

    Employee commitment is a concept that seeks to capture the nature of the attachments formed by individuals to their employing organisations. Researchers such as Porter have attempted to identify what factors influence the formation of employee commitment in individuals and how employee commitment (once formed) influences important organisational consequences, particularly employee turnover and business success. In a highly committed workplace, employees understand and agree with the company's...

  1. Susceptibility and Immune Defence Mechanisms of Rhynchophorus ferrugineus (Olivier (Coleoptera: Curculionidae against Entomopathogenic Fungal Infections

    Directory of Open Access Journals (Sweden)

    Abid Hussain

    2016-09-01

    Full Text Available Insects infected with entomopathogenic fungi, experience physiological changes that influence their growth and immune defence. The potential of nine isolates of entomopathogenic fungi was evaluated after determining percent germination and relative conidial hydrophobicity. However, nutritional indices were evaluated after immersing eighth-instar Rhynchophorus ferrugineus larvae into each isolate suspension (1 × 107 conidia/mL. The results showed that isolates B6884 and M9374 had 44.51% and 39.02% higher conidial hydrophobicity compared with isolate I03011 (least virulent. The results of nutritional index assays revealed a significant reduction in growth indices after infection with different isolates. Compared with control, B6884 and M9374 greatly decreased larval growth by reducing the efficacy of conversion of ingested food (36%–47% and Efficacy of conversion of digested food (50%–63%. Furthermore, only isolate B6884 induced 100% mortality within 12 days. Compared with control, isolate I03011, possessing the lowest conidial hydrophobicity, only reduced 0.29% of the efficacy of conversion of ingested food (ECI and 0.48% of the efficacy of conversion of digested food (ECD. Similarly, transcriptomic analysis of genes related to the Red palm weevil (RPW immune response, including pathogen recognition receptors (C-type lectin and endo-beta-1,4-glucanse, signal modulator (Serine protease-like protein, signal transductors (Calmodulin-like protein and EF-hand domain containing protein and effectors (C-type lysozyme, Cathepsin L., Defensin-like protein, Serine carboxypeptidase, and Thaumatin-like protein, was significantly increased in larval samples infected with B6884 and M9374. These results suggest that for an isolate to be virulent, conidial hydrophobicity and germination should also be considered during pathogen selection, as these factors could significantly impact host growth and immune defence mechanisms.

  2. Short exposure to acetylene to distinguish between nitrifier and denitrifier nitrous oxide production in soil and sediment samples

    NARCIS (Netherlands)

    Kester, R.A.; Boer, W. de; Laanbroek, H.J.

    1996-01-01

    The contribution of nitrifiers and denitrifiers to the nitrous oxide production in slurries of calcareous silt loam and river bank sediment at different oxygen concentrations was determined using acetylene as nitrification inhibitor. The addition of 10 Pa acetylene resulted in inhibition of

  3. Short exposure to acetylene to distinguish between nitrifier and denitrifier nitrous oxide production in soil and sediment samples

    NARCIS (Netherlands)

    Kester, R.A.; De Boer, W.; Laanbroek, H.J.

    1996-01-01

    The contribution of nitrifiers and denitrifiers to the nitrous oxide production in slurries of calcareous silt loam and river bank sediment at different oxygen concentrations was determined using acetylene as nitrification inhibitor. The addition of 10 Pa acetylene resulted in inhibition of nitrous

  4. Water deficit stress effects on corn (Zea mays, L.) root: shoot ratio

    Science.gov (United States)

    A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation...

  5. Transitional Effects of Double-Lateral Drip Irrigation and Straw Mulch on Irrigation Water Consumption, Mineral Nutrition, Yield, and Storability of Sweet Cherry

    Science.gov (United States)

    A field trial was conducted on a Cherryhill silt loam soil at The Dalles, OR from 2006 through 2008. The impacts of switching from the traditional micro sprinkler irrigation (MS) to double-lateral drip irrigation (DD) and from no ground cover with herbicide control of weeds (NC) to in-row wheat (Tri...

  6. Comparative research on tillable properties of diatomite-improved soils in the Yangtze River Delta region, China.

    Science.gov (United States)

    Qu, Ji-Li; Zhao, Dong-Xue

    2016-10-15

    To improve soil texture and structure, techniques associated with physical, biological or chemical aspects are generally adopted, among which diatomite is an important soil conditioner. However, few studies have been conducted to investigate the physical, hydraulic and tillage performance of diatomite-improved soils. Consistency limits and compaction properties were investigated in this study, and several performance indicators were compared, such as the liquid limit, plastic limit and compactability, of silt, silt loam and silty-clay loam soils to which diatomite was added at volumetric ratios of 0%, 10%, 20%, and 30%. The results showed that diatomite significantly (pdiatomite lowered the maximum dry bulk density (MBD) of the classified soils, the optimum moisture content (OMC) was increased overall. The trend was consistent with the proportion of diatomite, and MBD decreased by 8.7%, 10.3%, and 13.2% in the silt, silt loam and silty-clay loam soils when 30% diatomite was mixed, whereas OMC increased by 28.7%, 22.4%, and 25.3%, respectively. Additionally, aggregate stability was negatively correlated with MBD but positively correlated with OMC. Diatomite exerts positive effects on soil mechanical strength, suggesting that soils from sludge farms are more tillable with a larger stabilized and workable matrix. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Cottonwood Response to Nitrogen Related To Plantation Age and Site

    Science.gov (United States)

    B.G. Blackmon

    1977-01-01

    When applied at plantation age 4,336 kg N/ha increased diameter growth of cottonwood on Sharkey clay by 33 percent over unfertilized controls. Fertilizing at ages 2 and 3 resulted in no response, nor was there any benefit from applying nitrogen fertilizer to cottonwood on Commerce silt loam. On both sites, foliar N levels were increased by fertilization regardless of...

  8. Nitrogen Fertilization Increases Cottonwood Growth on Old-Field Soil

    Science.gov (United States)

    B. G. Blackmon; E. H. White

    1972-01-01

    Nitrogen (150 lb ./acre as NH4N03 ) applied to a 6-year-old eastern cottonwood plantation in an old field on Commerce silt loam soil increased diameter, basal area, and volume growth by 200 percent over untreated controls. The plantation did not respond to 100 pounds P per acre from concentrated superphosphate.

  9. Control of Eolian soil erosion from waste site surface barriers

    International Nuclear Information System (INIS)

    Ligotke, M.W.

    1994-11-01

    Physical models were tested in a wind tunnel to determine optimum surface-ravel admixtures for protecting silt-loam soil from erosion by, wind and saltating, sand stresses. The tests were performed to support the development of a natural-material surface barrier for and waste sites. Plans call for a 2-m deep silt-loam soil reservoir to retain infiltrating water from rainfall and snowmelt. The objective of the study was to develop a gravel admixture that would produce an erosion-resistant surface layer during, periods of extended dry climatic stress. Thus, tests were performed using simulated surfaces representing dry, unvegetated conditions present just after construction, after a wildfire, or during an extended drought. Surfaces were prepared using silt-loam soil mixed with various grades of sand and Travel. Wind-induced surface shear stresses were controlled over the test surfaces, as were saltating, sand mass flow rates and intensities. Tests were performed at wind speeds that approximated and exceeded local 100-year peak gust intensities. Surface armors produced by pea gravel admixtures were shown to provide the best protection from wind and saltating sand stresses. Compared with unprotected silt-loam surfaces, armored surfaces reduced erosion rates by more than 96%. Based in part on wind tunnel results, a pea gravel admixture of 15% will be added to the top 1 in of soil in a prototype barrier under construction in 1994. Field tests are planned at the prototype site to provide data for comparison with wind tunnel results

  10. Wind erosion potential of a winter wheat–summer fallow rotation after land application of biosolids

    Science.gov (United States)

    While land application of biosolids is recognized as a sustainable management practice for enhancing soil health, no studies have determined the effects of biosolids on soil wind erosion. Wind erosion potential of a silt loam was assessed using a portable wind tunnel after applying synthetic and bio...

  11. Improvement, Verification, and Refinement of Spatially-Explicit Exposure Models in Risk Assessment - SEEM

    Science.gov (United States)

    2015-06-01

    is Beltsville silt loam. Land use in the watershed is mainly upland or wetland forests, with significant urban and agricultural development. The...covered with extensive woodlands and wetlands that provide habitat for many animals, including white tail deer, foxes, and wild turkeys. The area is

  12. Improvement, Verification, and Refinement of Spatially Explicit Exposure Models in Risk Assessment - SEEM Demonstration

    Science.gov (United States)

    2015-06-01

    is Beltsville silt loam. Land use in the watershed is mainly upland or wetland forests, with significant urban and agricultural development. The...covered with extensive woodlands and wetlands that provide habitat for many animals, including white tail deer, foxes, and wild turkeys. The area is

  13. Effects of Field Conditions on Emergence of Oilseed Rape Seed lots Grown in Khorasan Province

    Directory of Open Access Journals (Sweden)

    A Yanegh

    2014-07-01

    Full Text Available Nineteen irrigated farms of canola from six cities of Khorasan selected to assess the seedling emergence one month after sowing in 2009. Soil texture of each farm determined using the Hydrometer method. The results showed that weather conditions of sowing areas had no significant effect on emergence of oilseed rape. With increasing the temperature (within the range of 19.5 to 21.5 ˚C emergence percentage was not increased significantly. Rainfall also caused no significant effect on seedling emergence. The percentage of emergence in machine-sowing and hand-sowing were 38.4% and 28%, respectively. Soils with loam silt, silt clay loam and loam texture had emergence of 27.2%, 31.2% and 47% respectively. It seems soil texture plays a great roll on the emergence of oilseed rape with epigeal seedlings.

  14. [Development of APSIM (agricultural production systems simulator) and its application].

    Science.gov (United States)

    Shen, Yuying; Nan, Zhibiao; Bellotti, Bill; Robertson, Michael; Chen, Wen; Shao, Xinqing

    2002-08-01

    Soil-crop simulator model is an effective tool for providing decision on agricultural management. APSIM (Agricultural Production Systems Simulator) was developed to simulate the biophysical process in farming system, and particularly in the economic and ecological features of the systems under climatic risk. The current literatures revealed that APSIM could be applied in wide zone, including temperate continental, temperate maritime, sub-tropic and arid climate, and Mediterranean climates, with the soil type of clay, duplex soil, vertisol, silt sandy, silt loam and silt clay loam. More than 20 crops have been simulated well. APSIM is powerful on describing crop structure, crop sequence, yield prediction, and quality control as well as erosion estimation under different planting pattern.

  15. Pupation Behaviors and Emergence Successes of Ectropis grisescens (Lepidoptera: Geometridae) in Response to Different Substrate Types and Moisture Contents.

    Science.gov (United States)

    Wang, Huifang; Ma, Tao; Xiao, Qiang; Cao, Panrong; Chen, Xuan; Wen, Yuzhen; Xiong, Hongpeng; Qin, Wenquan; Liang, Shiping; Jian, Shengzhe; Li, Yanjun; Sun, Zhaohui; Wen, Xiujun; Wang, Cai

    2017-12-08

    Ectropis grisescens Warren (Lepidoptera: Geometridae) is one of the most severe pests of tea plants in China. This species commonly pupates in soil; however, little is known about its pupation ecology. In the present study, choice and no-choice tests were conducted to investigate the pupation behaviors and emergence success of E. grisescens in response to different substrates (sand, sandy loam 1, sandy loam 2, and silt loam) and moisture contents (5, 20, 35, 50, 65, and 80%). Moisture-choice bioassays showed that significantly more E. grisescens individuals pupated in or on soil (sandy loam 1 and 2 and silt loam) that was at the intermediate moisture levels, whereas 5%- and 35%-moisture sand was significantly more preferred over 80%-moisture sand for pupating. Substrate-choice bioassays showed that sand was most preferred by E. grisescens individuals at 20%- and 80%-moisture levels, but no preference was detected among the four substrates at 50%-moisture content. No-choice tests showed that the percentage of burrowed E. grisescens individuals and pupation depth were significantly lower when soil was dry (20% moisture) or wet (80% moisture). In addition, 20%-moisture sandy loam 2 and silt loam significantly decreased the body water content of pupae and emergence success of adults compared to 50%-moisture content. However, each measurement (percentage of burrowed individuals, pupation depth, body water content, or emergence success) was similar when compared among different moisture levels of sand. Interestingly, pupae buried with 80%-moisture soil exhibited significantly lower emergence success than that were unburied. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  16. Manure biochar influence upon soil properties, phosphorus distribution and phosphatase activities: A microcosm incubation study.

    Science.gov (United States)

    Jin, Yi; Liang, Xinqiang; He, Miaomiao; Liu, Yu; Tian, Guangming; Shi, Jiyan

    2016-01-01

    Using manure-derived-biochar as an alternative phosphorus (P) source has bright future prospects to improve soil P status. A 98-day microcosm incubation experiment was set up for two soils which were amended with manure biochar at proportions of 0, 0.5% and 1.5%. Swine manure samples were air-dried and manure biochar was prepared by pyrolysis at 400 °C for 4 h. As determined by P-31 nuclear magnetic resonance ((31)P NMR) spectroscopy, manure biochar mainly increased the contents and fractions of orthophosphate and pyrophosphate in two soils, while decreased those of monoesters (P<0.05). At the end of incubation, 1.5% of manure biochar raised soil pH by 0.5 and 0.6 units, cation exchange capacity by 16.9% and 32.2%, and soil total P by 82.1% and 81.1% for silt loam and clay loam soils, respectively, as compared with those soils without biochar. Simultaneously, 1.5% of manure biochar decreased acid phosphomonoesterase activities by 18.6% and 34.0% for clay loam and silt loam, respectively; while it increased alkaline phosphomonoesterase activities by 28.5% and 95.1% for clay loam and silt loam, respectively. The enhancement of soil P availability after manure biochar addition was firstly due to the orthophosphate and pyrophosphate as the major P species in manure biochar which directly increased contents of soil inorganic P, and also attributed to the decomposition of some organic P like monoesters by enhanced alkaline phosphomonoesterase activities from manure biochar addition. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Influence of Soil Based Growing Media on Vegetative Propagation of Selected Cultivars of Olea Europaea

    International Nuclear Information System (INIS)

    Ahmed, M. I.; Ashraf, M. I.; Malik, S. U.; Husaain, Q.

    2016-01-01

    Pothwar region of Pakistan is a natural habitat of Olea spp. There is a high demand of certified olive plants to establish olive orchids in the region, because native wild species are non-fruit bearing. Plants of certified fruit bearing olive (Olea europaea L.) cultivars are rarely available. Vegetative propagation of olive is highly responsive to texture of soil based growing media. This study examined the effect of growing media composition (soil texture and nutrients) on vegetative propagation of five cultivars of olive. The experiment was carried out in randomized complete block design (RCBD) with two factors factorial having 25 repeats of each four treatments. Plant growth and survival data were collected and analyzed for the influence of soil attributes. In sandy loam soil, cv. Bari-1 had 82 percent plant survival, highest number of roots per plant (3.5), and longest root length (13.01 cm). Highest number of shoots per plant (4.25) and maximum shoot length (15.64 cm) were also recorded for Bari-1 with sandy loam growing media. Silt loam soil is least suitable growing media for vegetative propagation of olive. In the silt loam soil, plants survival rate was 59 percent for cv. Gemlik, number of roots per plant was 1.5 for cv. Ottobrattica, minimum root length 5.65 cm, minimum number of shoots per plant one, and minimum shoot length 7.42 cm were recorded for cv. Pendolino with silt loam soil. Results suggested that sandy loam growing media is better than the others for vegetative propagation of olive. Cultivar Bari-1 performed better than the others examined in this study by indicating highest (1) survival percentage, (2) root and shoot length, and (3) number of roots and shoots produced within a specific period of time. (author)

  18. Conservation of nitrate during the fallow; Conservacion del nitrogeno durante el barbecho

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez Aguilar, M.

    2004-07-01

    We study the possibility to use the waste-water from olive oil mills, or woom to reduce the leaching, of nitrate during the fallow. The blocking in time that practice the woom about the nitrogen of soil we are suggest this study. We make use of woom dilute in water and we study the influence,as soon as the contained potassium, on the nitrogen leaching of two soils, loam and silt-clay loam. The irrigation of soils with woom dilute in water from ten to forty times prior to the autumnal rains to be worth for reducing the leaching of nitrate during the fallow. (Author) 21 refs.

  19. Microstructure and stability of two sandy loam soils with different soil management

    NARCIS (Netherlands)

    Bouma, J.

    1969-01-01

    A practical problem initiated this study. In the Haarlemmermeer, a former lake reclaimed about 1850, several farmers had difficulties with soil structure. Land, plowed in autumn, was very wet in spring. Free water was sometimes present on the soil surface. Planting and seeding were long delayed in

  20. Free flow spillways on loam dams; Deversoirs a ecoulement libre sur des digues en terre

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-12-31

    The free flow spillways technique was developed abroad and has been used and developed in France by two research offices and foremen. Dams of this type can have heights of 8 to 20 m and both dams and spillways must fit with special technical characteristics which are described (drainage, joints, reinforcements, wall surface, embankment etc..). The experience of French foremen with this type of dams and spillways is reported. (J.S.)

  1. Soil resistance and resilience to mechanical stresses for three differently managed sandy loam soils

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Schjønning, Per; Møldrup, Per

    2012-01-01

    carbon (CCCsoils to compaction using air permeability (ka), void ratio (e) and air-filled porosity (ε) as functional indicators and to characterise aggregate stability, strength and friability. Aggregate tensile strength...... the compression index and a proposed functional index,was significantly greater for theMFC soil compared to the other two soils. The change in compression index with initial void ratio was significantly less for the MFC than the other soils. Plastic reorganisation of the soil particles immediately after......To improve our understanding of how clay-organic carbon dynamics affect soil aggregate strength and physical resilience, we selected three nearby soils (MFC,Mixed Forage Cropping; MCC,Mixed Cash Cropping; CCC, Cereal Cash Cropping)with identical clay content and increasing contents of organic...

  2. Predictivity strength of the spatial variability of phenanthrene sorption across two sandy loam fields

    DEFF Research Database (Denmark)

    Soares, Antonio; Paradelo Pérez, Marcos; Møldrup, Per

    2015-01-01

    Sorption is commonly suggested as the major process underlying the transport and fate of polycyclic aromatic hydrocarbons (PAHs) in soils. However, studies focusing in spatial variability at the field scale in particular are still scarce. In order to investigate the sorption of phenanthrene...

  3. Persistence of bifenthrin in sandy loam soil as affected by microbial community.

    Science.gov (United States)

    Sharma, Divya; Singh, Shashi Bala

    2012-06-01

    Soil was fortified with bifenthrin at the level of 10 μg g(-1) soil. Soil samples were drawn at regular intervals of 0, 10, 20, 30 and 40 days. For extraction of bifenthrin, soil was extracted with acetone. Clean up was done by liquid-liquid partitioning with dichloromethane after diluting with brine solution. Quantification of bifenthrin residues was done by GC using mega bore column and ECD detector. Recovery of bifenthrin in soil ranged between 92.6 % and 93.8 % at 0.5 and 1.0 μg g(-1). The instrumental limit of detection of bifenthrin was 0.005 μg mL(-1) and LOQ for soil by this method was found to be 0.05 μg g(-1). The calibration curve was found to be linear within range the range of 0.01 and 0.10 μg mL(-1) concentration. The DT(50) (disappearance time for 50 % loss) of bifenthrin at the level of 10 μg g(-1) in sterile and non sterile soil were found to be 330 and 147 days, respectively. A vast difference in the half life of sterile and non sterile soil indicated the presence of potential microbes for bifenthrin degradation.

  4. Carbon dioxide emissions after application of different tillage systems for loam in northern China

    Science.gov (United States)

    Hongwen, Li; Lifeng, Hu; Fub, Chen; Xuemin, Zhang

    2010-05-01

    Tillage operations influence soil physical properties and crop growth, and thus both directly and indirectly the cropland CO2 exchange with the atmosphere. In this study, the results of CO2 flux measurements on cropland, under different tillage practices in northern China, are presented. CO2 flux on croplands with a winter wheat (Triticum aestivum L.) and maize (Zea may L.) rotation was monitored on plots with conventional tillage (CT), rotary tillage (RT) and no tillage (NT). Soil CO2 flux was generally greater in CT than in NT, and the RT CO2 flux was only slightly smaller than the CT. Daily soil CO2 emissions for CT, RT, and NT averaged 11.30g m-2, 9.63 g m-2 and 7.99 g m-2, respectively, during the growing period. Analysis of variance shows that these differences are significant for the three tillage treatments. Peak CO2 emissions were recorded on the CT and RT croplands after tillage operations. At the same time, no obviously increased emission of CO2 occurred on the NT plot. These differences demonstrate that tillage results in a rapid physical release of CO2.

  5. Improving the Bearing Strength of Sandy Loam Soil Compressed Earth Block Bricks Using Sugercane Bagasse Ash

    Directory of Open Access Journals (Sweden)

    Ramadhan W. Salim

    2014-06-01

    Full Text Available The need for affordable and sustainable alternative construction materials to cement in developing countries cannot be underemphasized. Compressed Earth Bricks have gained acceptability as an affordable and sustainable construction material. There is however a need to boost its bearing capacity. Previous research show that Sugarcane Bagasse Ash as a soil stabilizer has yielded positive results. However, there is limited research on its effect on the mechanical property of Compressed Earth Brick. This current research investigated the effect of adding 3%, 5%, 8% and 10% Sugarcane Bagasse Ash on the compressive strength of compressed earth brick. The result showed improvement in its compressive strength by 65% with the addition of 10% Sugarcane Bagasse Ash.

  6. Effect of industrial, municipal and agricultural wastes on peanut in lateritic sandy loam soil

    International Nuclear Information System (INIS)

    Sarkar, S.; Khan, A.R.

    2002-06-01

    Modern agriculture, worldwide, depends upon the external application of plant nutrients supplied mostly through chemical fertilizer to meet the crop needs. The natural recycling cannot provide the very large amount of nutrients needed year after year in an intensive cropping system and nutrients being a major constraint harvesting the nutrient energy from biological and industrial waste are of prime importance for maximizing the food grain production in the world. A number of industrial wastes like fly ash from thermal power plants, paper factory sludge from paper factory, sewage sludge from municipal source and farmyard manure from livestock farming are the important waste resources, having potentiality in recycling in agricultural land. When these wastes are recycled through soil for crop production, due to the degradative and assimilative capacity of soil, the pollution hazards of these wastes can be minimized to a greater extent as compared to direct disposing of at the site. Fly ash is a waste product residue resulting from the combustion of pulverised coal in coal-fired power generating station. Physico - chemical analysis of fly ash has revealed the presence of both macro-micro nutrients, which can sustain plant growth. Its application in the agricultural land acts as a liming material and improves crop growth by neutralizing the soil acidity, increasing the water availability for the plants and supplement of nutrients (Adriano et al, 1980, Molliner and Street, 1982, Schnappinger et al, 1975). Application of paper factory sludge has been reported to increase the organic carbon content in soil and nutrient content like P, K, Ca, Mg and micronutrients (Guerini et al, 1994, Muse and Mitchell, 1995). Sludge application also improves the organic carbon content of the soil and availability of nutrients like Ca, K and Mg besides improvement of physical properties (Pitchel and Hayes, 1990). Much is known regarding crop performance and changes in physical and chemical properties of soil due to the application of such organic wastes. However, little is explored regarding the influence of various wastes on soil microbiology and its impact on nodulation and yield of leguminous crop like peanut. Soil biology is a significant component of soil quality and is the catalytic agent responsible for many transformations occurring in soil, most notably the reactions involved in nutrient cycling (Karlen et al, 1997). Thus it is meaningful to evaluate the physical, chemical and biological aspects of soil quality by addition of such organic wastes. The aim of the study was to evaluate the influence of industrial, municipal and agricultural waste on the performance of a leguminous crop like peanut and on the total microbial and Rhizobium population in soil rhizosphere

  7. Effects of biochar and manure amendments on water vapor sorption in a sandy loam soil

    DEFF Research Database (Denmark)

    Arthur, Emmanuel; Tuller, Markus; Moldrup, Per

    2015-01-01

    Over the last few years, the application of biochar (BC) as a soil amendment to sequester carbon and mitigate global climate change has received considerable attention. While positive effects of biochar on plant nutrition are well documented, little is known about potential impacts on the physical....... Hysteresis of the water vapor sorption isotherms increased with increasing BC application rates. Biochar age did not significantly affect vapor sorption and SSA....

  8. Seasonal dynamics in wheel load-carrying capacity of a loam soil in the Swiss Plateau

    DEFF Research Database (Denmark)

    Gut, S.; Chervet, A.; Stettler, Matthias

    2015-01-01

    on in situ measurements of h, measurements of precompression stress at various h and simulations of soil stress. In this work, we concentrated on prevention of subsoil compaction. Calculations were made for different tyres (standard and low-pressure top tyres) and for soil under different tillage......Subsoil compaction is a major problem in modern agriculture caused by the intensification of agricultural production and the increase in weight of agricultural machinery. Compaction in the subsoil is highly persistent and leads to deterioration of soil functions. Wheel load-carrying capacity (WLCC......) is defined as the maximum wheel load for a specific tyre and inflation pressure that does not result in soil stress in excess of soil strength. The soil strength and hence WLCC is strongly influenced by soil matric potential (h). The aim of this study was to estimate the seasonal dynamics in WLCC based...

  9. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    .e. visual evaluation of soil structure (VESS), overall visual structure (OVS) and overall soil structure (OSS)) were employed to differentiate the effects of these alternative management practices on soil structural quality and relative crop yield (RY). A Pearson correlation was also employed to find...... the correlation between the soil quality indices and relative crop yield. Relevant soil properties for calculating the soil quality indices were measured or obtained from previous publications. Crop rotation affected the soil structure and RY. The winter-dominated crop rotation (R2) resulted in the poorest soil...... correlations were found in most cases between soil quality indices (including M-SQR) and RY. This highlights the influence of soil quality (as measured by the selected indicators) – and soil structure in particular – on crop yield potential....

  10. Anisotropy of the porosity in a silty loam soil under continuous no tillage management

    OpenAIRE

    Soracco, Carlos Germán; Lozano, Luis A.; Gelati, Pablo R.; Sarli, Guillermo O.; Filgueira, Roberto R.

    2008-01-01

    La superficie bajo siembra directa (SD) se incrementa continuamente en la Republica Argentina. Existen trabajos que muestran una orientación preferencial de los poros en sentido horizontal cerca de la superficie de suelos bajo SD. El objetivo específico de este trabajo fue evaluar la conductividad hidráulica saturada del horizonte superficial en sentido vertical y horizontal en SD continua con descompactación (SDCD) respecto de un testigo de SD sin descompactacion (SDSD) para determinar la ex...

  11. Crop residues as driver for N2O emissions from a sandy loam soil

    DEFF Research Database (Denmark)

    Pugesgaard, Siri; Petersen, Søren O.; Chirinda, Ngonidzashe

    2017-01-01

    -term experiment on a loamy sand soil at Foulum in Denmark. All cropping systems included winter wheat, a leguminous crop (faba bean or grass-clover), potato and spring barley grown in different 4-crop rotations varying in strategies for N supply (fertilizer/manure type and rate, use of catch crops and green......-N leaching losses ranged from 39 to 56 kg N ha−1 y−1 and were lowest in rotations with catch crops; leaching was not correlated with N surplus or N input in fertilizer or manure. Crop yields of the organic rotations were 25 to 37% lower than in identical conventional rotations. As a consequence, yield...

  12. Effect of bovine manure on fecal coliform attachment to soil and soil particles of different sizes.

    Science.gov (United States)

    Guber, Andrey K; Pachepsky, Yakov A; Shelton, Daniel R; Yu, Olivia

    2007-05-01

    Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt fraction, and the clay fraction of loam and sandy clay loam soils were separated and used along with soil samples in batch attachment experiments with water-FC suspensions and water-manure-FC suspensions. In the absence of manure colloids, bacterial attachment to soil, silt, and clay particles was much higher than the attachment to sand particles having no organic coating. The attachment to the coated sand particles was similar to the attachment to silt and clay. Manure colloids in suspensions decreased bacterial attachment to soils, clay and silt fractions, and coated sand fractions, but did not decrease the attachment to sand fractions without the coating. The low attachment of bacteria to silt and clay particles in the presence of manure colloids may cause predominantly free-cell transport of manure-borne FC in runoff.

  13. Histology and histochemistry of the venom apparatus of the black scorpion Androctonus crassicauda (Olivier, 1807 (Scorpiones: Buthidae

    Directory of Open Access Journals (Sweden)

    BM Jarrar

    2008-01-01

    Full Text Available The venom apparatus of the black scorpion Androctonus crassicauda has been characterized histologically and histochemically in the present study. The results showed that this apparatus consists of paired venom glands, each of which initially presents its own canal and posteriorily both fuse into a single common one. Each gland is covered by a sheath of striated muscle and is lined with extensively folded secretory epithelium (formed of non-secretory and secretory venom-producing cells. The outcomes also revealed that the venom-producing cells of both glands produce neutral mucosubstances, sialomucins, sulfomucins and proteins, but are devoid of glycogen. Cysteine, tyrosine, tryptophan and arginine were also detected along with activities of acid and alkaline phosphatases, mitochondrial adenosine triphosphatase, aminopeptidase, cholinesterase and non-specific esterases. Structure and secretion of scorpion venom glands are discussed within the context of the present results.

  14. Taassündinud selleks, et tappa / Olivier Roy ; tõlk. Külli-Riin Tigasson

    Index Scriptorium Estoniae

    Roy, Olivier

    2005-01-01

    Islami radikaliseerumisest, fundamentalismist. Autori väitel annavad kristlik ja islamiäärmuslus tunnistust üleilmastumise ajastu kultuurikriisist, islamiäärmusluse kasvulava on eeskätt noorte Euroopa muslimite teine põlvkond

  15. Changes in pheromone production, release, mating behaviour and reproductive ability of the gamma-irradiated cockroach Nauphoeta cinerea (Olivier)

    International Nuclear Information System (INIS)

    Menon, M.

    1978-01-01

    Mature males of Nauphoeta cinerea produce a sex pheromone 'seducin' which has short-range effects in attracting mature females of the same species. Exposure of newly-emerged adult males to 3.5, 7, 14 or 21 krad of gamma-radiation decreased their life expectancy and affected their mating behaviour. Bioassay of dichloromethane extracts of males showed that radiation doses (14 krad) sufficient to induce sterility did not affect the ability to produce pheromone but significantly reduced the release of pheromone by inhibiting wing-raising. The sterile-male technique using males sterilized by ionizing radiation in air may not be the method of choice for control of Nauphoeta cinerea. (author)

  16. Evaluation of Analgesic Activity of the Methanol Extract from the Galls of Quercus infectoria (Olivier in Rats

    Directory of Open Access Journals (Sweden)

    Sook-Ha Fan

    2014-01-01

    Full Text Available The present study aims to investigate the analgesic activity of the methanol extract of the galls of Quercus infectoria in rats using hot plate and tail-flick methods. The extract was administered intraperitoneally at a dose of 20 mg/kg while morphine sulfate and sodium salicylate (10 mg/kg served as standards. The methanol extract exhibited significant analgesic activity in the tail-flick model (P<0.05 by increasing the reaction time of the rats to 8.0 sec at 30 min after treatment in comparison to control (4.4 sec. Morphine sulfate produced a reaction time of 11.9 sec in the same test. At the peak of activity (30 min, the extract produced maximum possible analgesia (MPA of 34.2%, whilst morphine sulfate achieved a peak MPA of 70.9%. No analgesic effects have been observed using sodium salicylate in the tail-flick model. In the same model, the extract and sodium salicylate demonstrated comparable reaction times. Tail-flick is a better method to evaluate analgesic activity as no significant results were observed for all treatments using hot plate with the exception of morphine sulfate, which showed significant results only at 45 and 60 min after treatment. In conclusion, the methanol extract of the galls of Quercus infectoria displayed analgesic activity.

  17. Effet du milieu de culture sur le microbouturage de l'olivier (Olea europeae L. cv. Picholine Marocaine

    Directory of Open Access Journals (Sweden)

    Abousalim A.

    2003-01-01

    Full Text Available Effect of culture medium on micropropagation of olive (Olea europeae L. cv. Moroccan Picholine. The effect of the basal media OM (Olive Medium, 1/2 MS (Murashige et Skoog with half strength macronutrients, WPM (Lloyd and McCown, 1/2 Miller (Miller with half strength macronutrients, and K&H (medium with Knop macronutrients and Heller micronutrients, supplemented with 5 mg/l Zeatine, on shoot proliferation of mature ‘Moroccan Picholine'cultivar (30 years old was investigated. OM and 1/2 MS media were the most effective at the early stages of proliferation. A microcutting percentage of up to 91,6 and 90,9 % were achieved in OM and 1/2 MS media respectively but OM was distinguished later by permitting a better shoot growth with no vitrification symptoms The highest percentages of new shoots per explant were obtained with 1/2 MS and OM media (67 and 65 % respectively. OM was the most effective for shoot height (12,42 mm followed by 1/2 MS (8,92 mm. The other tested media induced an important callus development and leaf chlorosis, and the reduction of shoot growth was noticeable.

  18. Investigation of the transport of actinide-bearing soil colloids in the soil-aquatic environment

    International Nuclear Information System (INIS)

    Sheppard, J.C.; Campbell, M.J.; Kittrick, J.; Cheng, T.

    1980-04-01

    Uranium-233 particle size dependent distribution ratios for the 10 to 60 range were determined for muscatine silt loam, Burbank loamy sand, Ritzville silt loam, Fuquay sand, and Idaho sandy clay. A mathematical method for the analysis of centrifuge data was developed to determine particle size dependent distribution ratio for the 10 to 60 nm range. Comparison of the distribution ratio data for the 0 to 60 nm particle size range strongly suggests that particles in the 1 to 10 nm (8000 to 50,000 MW) range play a dominate role. Since these particles are probably humic acid polymers, future research should be focused on humic acid complexing of radionuclides. A mathematical analysis is given to demonstrate the role of humic acid complexing in the transport of radionuclides in the soil-aquatic environment

  19. Suspended silt and salinity tolerances of the first zoeal stage of the ...

    African Journals Online (AJOL)

    undergo the zoeal stage of development in open-ocean waters, where they experience stable salinity levels, low turbidity and reduced predation. The St ... Despite recent attempts to improve marine connectivity, it remains limited, occurring primarily on the flood tide through channels connected to the adjacent Mfolozi River.

  20. Interrill erosion of carbon and phosphorus from conventionally and organically farmed Devon silt soils

    DEFF Research Database (Denmark)

    Kuhn, Nikolaus J; Armstrong, Elizabeth K; Ling, Amy C

    2012-01-01

    particles by raindrop impacted flow. Resistance to interrill erosion varies between soils depending on their physical, chemical and mineralogical properties. In addition, significant changes in soil resistance to interrill erosion occur during storms as a result of changes in surface roughness, cohesion...... to conventional soil management. The enrichment of P and C in the interrill sediment was not directly related to SOC, P content of the soil and soil interrill erodibility. A comparison of soil and sediment properties indicates that crusting, P and C content as well as density and size of eroded aggregate......Globally, between 0.57 and 1.33 Pg of soil organic carbon (SOC) may be affected by interrill processes. Also, a significant amount of phosphorus (P) is contained in the surface soil layer transformed by raindrop impact, runoff and crust formation. In the EU, the P content of a crusted (2 mm...

  1. Full utilization of silt density index (SDI) measurements for seawater pre-treatment

    KAUST Repository

    Wei, Chunhai; Laborie, Sté phanie; Ben Aï m, Roger M.; Amy, Gary L.

    2012-01-01

    according to the standard protocol for SDI measurement, in which two kinds of 0.45μm membranes of different material and seawater samples from the Mediterranean including raw seawater and seawater pre-treated by coagulation followed by sand filtration (CSF

  2. Radionuclides behaviour in the silts-water system of a cooling pond

    International Nuclear Information System (INIS)

    Ol'khovik, Yu.A.; Kostyuchenko, N.G.; Koromyslichenko, T.I.

    1989-01-01

    As a result of the Chernobyl' accident a considerable amount of radioisotopes (1-5x10 5 Ci) concentrated in a cooling pond. A year later the accident a level of water contamination decreased by 2 orders, whereas the radionuclide distribution changed perceptibly. Processes of water self-decontamination in the cooling pond were considered. A forecast of water radiactivity level in the cooling pond in the summer of 1988 was made. 3 refs.; 1 refs.; 2 tabs

  3. Acoustic measurement of suspensions of clay and silt particles using single frequency attenuation and backscatter

    Science.gov (United States)

    The use of ultrasonic acoustic technology to measure the concentration of fine suspended sediments has the potential to greatly increase the temporal and spatial resolution of sediment measurements while reducing the need for personnel to be present at gauging stations during storm events. The conv...

  4. Silt density index and modified fouling index relation, and effect of pressure, temperature and membrane resistance

    NARCIS (Netherlands)

    Al-Hadidi, A.M.M.; Alhadidi, A.; Kemperman, Antonius J.B.; Blankert, B.; Blankert, B.; Schippers, J.C.; Wessling, Matthias; van der Meer, Walterus Gijsbertus Joseph

    2011-01-01

    Particulate matter present in feed water of reverse osmosis and nanofiltration membrane elements tends to deposit on the membrane surface and spacers. This type of fouling results in permeate flux decline, loss of product quality and membrane damage. To characterize the fouling potential of RO feed

  5. Reduction in wick drain effectiveness with spacing for Utah silts and clays.

    Science.gov (United States)

    2012-04-01

    Although decreasing the spacing of vertical drains usually decreases the time for consolidation, previous field tests have shown that there is a critical drain spacing for which tighter spacing does not decrease the time for consolidation. This...

  6. The Silting-Up Prevention in the Geothermal Absorbent Openings of Geothermal Energy Plant Pyrzyce

    Directory of Open Access Journals (Sweden)

    Noga Bogdan

    2014-06-01

    Full Text Available The paper presents precipitation results from cold thermal water deposits that are the main cause of clogging in absorbent geothermal wells and borehole areas. As a result of physical and chemical analysis, laboratory tests and observation of the operation of a geothermal installation, a new method was developed to prevent the precipitation of sludge from cooled thermal water. The method being a modification of soft acidising was tentatively named as a super soft acidising method

  7. Sediment-worm interaction: transfer of 65Zn from marine silt by the polychaete, Nereis diversicolor

    International Nuclear Information System (INIS)

    Renfro, W.C.; Benayoun, G.

    1976-01-01

    Marine polychaete worms (Nereis diversicolor) accumulated 65 Zn sorbed to silty marine sediment for 5 days and were then transferred to nonradioactive sediment in the laboratory and in the sea. The mean biological half-life (T/sub B//2/) for the laboratory worms did not differ greatly from that for worms in the sea. Worms living in small flowing seawater systems containing 16 cm 3 of sediment accumulated 65 Zn added to each system in the form of radioactive organic detritus. Higher percentage uptake of 65 Zn was from radioactive detritus particles 0.2 to 2 mm in diameter resting on the sediment surface or mixed with sediment than from finely-ground ( 65 Zn coprecipitated from fresh water with Fe(OH) 3 was accumulated by N. diversicolor when the precipitate was on the sediment surface than when the precipitate was well mixed with the sediment. These experimental results indicate that benthic organisms may take up limited amounts of heavy metals associated with bottom sediments and recycle them to benthic and pelagic food webs

  8. Effects of Conventional and Conservation Tillage on Soil Hydraulic Properties of a Silty-loamy Soil

    DEFF Research Database (Denmark)

    Wahl, Niels Arne; Bens, O.; Buczko, U.

    2004-01-01

    Infiltration into soils is strongly correlated with macroporosity. Under agricultural land use, the properties of the macropore network are governed by the applied management and tillage system. On an experimental site with a silt loam soil partly under conventional and conservation tillage, the ......, conservation tillage could possibly offer a means to reduce surface runoff and flood generation in agricultural landscapes dominated by silty-loamy soils. d 2...

  9. Short exposure to acetylene to distinguish between nitrifier and denitrifier nitrous oxide production in soil and sediment samples

    OpenAIRE

    Kester, R.A.; Boer, W. de; Laanbroek, H.J.

    1996-01-01

    The contribution of nitrifiers and denitrifiers to the nitrous oxide production in slurries of calcareous silt loam and river bank sediment at different oxygen concentrations was determined using acetylene as nitrification inhibitor. The addition of 10 Pa acetylene resulted in inhibition of nitrous oxide production at oxic conditions, but strongly enhanced the nitrous oxide production at oxygen-poor and anoxic conditions. Inhibition of nitrification by short exposure (1 to 24 h) to high conce...

  10. Chemical Weed Control Increases Survival and Growth in Hardwood Plantings

    Science.gov (United States)

    Gayne G. Erdmann

    1967-01-01

    In a plantation of four hardwood species on a silt loam soil planted to 1-0 stock, 4 pounds of active atrazine or simazine controlled weeds effectively without injuring the trees. Chemical weed control was better on plowed and disked ground than on unprepared ground. Yellow-poplar and white ash grew faster on prepared ground. Black walnut and red oak did not respond...

  11. Bioaugmentation for Aerobic Bioremediation of RDX-Contaminated Groundwater

    Science.gov (United States)

    2016-06-01

    sampling. The surface soil is characterized as a sandy loam soil (78% sand, 6% silt, 16% clay ) with a pH of 8.4, an organic carbon content of < 0.1...biomass is disposed of according to local ordinances (e.g., sterilized and directed into a municipal sanitary sewer). E.3. Use Information and...sterilized and directed into a municipal sanitary sewer). E.3. Use Information and Consumer Exposure Cultures are being used solely for field

  12. Identification of Soil Properties and Organophosphate Residues From Agricultural Land in Wanasari Sub-District, Brebes, Indonesia

    Science.gov (United States)

    Joko, Tri; Anggoro, Sutrisno; Sunoko, Henna Rya; Rachmawati, Savitri

    2018-02-01

    Organophosphates have been used to eradicate pests and prevent losses from harvest failures caused by pest attack. It is undeniable that the organophosphate persist in soil. This study aims to identify the organophosphate residue and soil properties include pH, soil texture, and permeability. The soil samples were taken from cropland in 10 villages, Wanasari sub-district, Brebes, Indonesia. Organophosphate residue determined by gas chromatography using Flame Photometric Detector. Soil texture was determined by soil texture triangle from NRCS USDA, and the permeability value was determined by falling head method. The mean value of chlorpyrifos, profenofos, diazinon were 0.0078; 0.0388; 0.2271 mg/l respectively. The soil texture varies from clay, silt clay, loam, silt loam, and silt clay loam with permeability value at 10-7 with the soil pH value between 6.4 - 8.1. The results showed that organophosphate residues found in the soil and its potential affect the soil fertility decline. We recommend to conduct routine soil quality analysis to prevent soil damage in the agricultural environment.

  13. Volatilization of gasoline from soil

    International Nuclear Information System (INIS)

    Arthus, P.

    1993-05-01

    Gasoline contaminated soil threatens water resources and air quality. The extent of the threat depends on gasoline behavior in soil, which is affected by various mechanisms such as volatilization. To quantify volatilization, gasoline spills were simulated in the laboratory using a synthetic gasoline and three dry soils. Total gasoline and individual gasoline compound concentrations in soil were monitored as a function of depth and time. The time to reduce overall gasoline concentration in coarse sand, sandy loam, and silt loam to 40% of initial concentration, averaged between surface and a 200-mm depth, ranged from 0.25 d to 10 d. A wicking phenomenon which contributed to gasoline flux toward the atmosphere was indicated by behavior of a low-volatility gasoline compound. Based on separate wicking experiments, this bulk immiscible movement was estimated at an upward velocity of 0.09 m/d for Delhi sandy loam and 0.05 m/d for Elora silt loam. 70 refs., 24 figs., 34 tabs

  14. How do changes in bulk soil organic carbon content affect carbon concentrations in individual soil particle fractions?

    Science.gov (United States)

    Yang, X. M.; Drury, C. F.; Reynolds, W. D.; Yang, J. Y.

    2016-06-01

    We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (<2 μm), silt (2-53 μm) and sand (53-2000 μm) particle size fractions. The OC concentrations in bulk soil ranged from 4.7 to 70.8 g C kg-1 soil. The OC concentrations on all three particle size fractions were significantly related to the OC concentration of bulk soil. However, OC concentration increased slowly toward an apparent maximum on silt and clay, but this maximum was far greater than the maximum predicted by established C sequestration models. In addition, significant increases in OC associated with sand occurred when the bulk soil OC concentration exceeded 30 g C kg-1, but this increase occurred when the OC concentration on silt + clay was still far below the predicted storage capacity for silt and clay fractions. Since the OC concentrations in all fractions of Brookston clay loam soil continued to increase with increasing C (bulk soil OC content) input, we concluded that the concept of OC storage capacity requires further investigation.

  15. Effects of biochar addition to soil on nitrogen fluxes in a winter wheat lysimeter experiment

    Science.gov (United States)

    Hüppi, Roman; Leifeld, Jens; Neftel, Albrecht; Conen, Franz; Six, Johan

    2014-05-01

    Biochar is a carbon-rich, porous residue from pyrolysis of biomass that potentially increases crop yields by reducing losses of nitrogen from soils and/or enhancing the uptake of applied fertiliser by the crops. Previous research is scarce about biochar's ability to increase wheat yields in temperate soils or how it changes nitrogen dynamics in the field. In a lysimeter system with two different soils (sandy/silt loam) nitrogen fluxes were traced by isotopic 15N enriched fertiliser to identify changes in nitrous oxide emissions, leaching and plant uptake after biochar addition. 20t/ha woodchip-waste biochar (pH=13) was applied to these soils in four lysimeters per soil type; the same number of lysimeters served as a control. The soils were cropped with winter wheat during the season 2012/2013. 170 kg-N/ha ammonium nitrate fertiliser with 10% 15N was applied in 3 events during the growing season and 15N concentrations where measured at different points in time in plant, soil, leachate and emitted nitrous oxide. After one year the lysimeter system showed no difference between biochar and control treatment in grain- and straw yield or nitrogen uptake. However biochar did reduce nitrous oxide emissions in the silt loam and losses of nitrate leaching in sandy loam. This study indicates potential reduction of nitrogen loss from cropland soil by biochar application but could not confirm increased yields in an intensive wheat production system.

  16. Occurrence, fate, and persistence of gemfibrozil in water and soil.

    Science.gov (United States)

    Fang, Yu; Karnjanapiboonwong, Adcharee; Chase, Darcy A; Wang, Jiafan; Morse, Audra N; Anderson, Todd A

    2012-03-01

    Pharmaceuticals and personal care products (PPCPs) have emerged as a group of potential environmental contaminants of concern. The occurrence of gemfibrozil, a lipid-regulating drug, was studied in the influent and effluent at a wastewater treatment plant (WWTP) and groundwater below a land application site receiving treated effluent from the WWTP. In addition, the sorption of gemfibrozil in two loam soils and sand was assessed, and biological degradation rates in two soil types under aerobic conditions were also determined. Results showed that concentrations of gemfibrozil in wastewater influent, effluent, and groundwater were in the range of 3.47 to 63.8 µg/L, 0.08 to 19.4 µg/L, and undetectable to 6.86 µg/L, respectively. Data also indicated that gemfibrozil in the wastewater could reach groundwater following land application of the treated effluent. Soil-water distribution coefficients for gemfibrozil, determined by the batch equilibrium method, varied with organic carbon content in the soils. The sorption capacity was silt loam > sandy loam > sand. Under aerobic conditions, dissipation half-lives for gemfibrozil in sandy loam and silt loam soils were 17.8 and 20.6 days, respectively; 25.4 and 11.3% of gemfibrozil was lost through biodegradation from the two soils over 14 days. Copyright © 2011 SETAC.

  17. Comparing Beerkan infiltration tests with rainfall simulation experiments for hydraulic characterization of a sandy-loam soil

    NARCIS (Netherlands)

    Prima, Di Simone; Bagarello, Vincenzo; Lassabatere, Laurent; Angulo-Jaramillo, Rafael; Bautista, Inmaculada; Burguet, Maria; Cerda Bolinches, Artemio; Iovino, Massimo; Prosdocimi, Massimo

    2017-01-01

    Saturated soil hydraulic conductivity, Ks, data collected by ponding infiltrometer methods and usual experimental procedures could be unusable for interpreting field hydrological processes and particularly rainfall infiltration. The Ks values determined by an infiltrometer

  18. Nitrate leaching from sandy loam soils under a double-cropping forage system estimated from suction-probe measurements.

    NARCIS (Netherlands)

    Trindade, H.; Coutinho, J.; Beusichem, van M.L.; Scholefield, D.; Moreira, N.

    1997-01-01

    Nitrate leaching from a double-cropping forage system was measured over a 2-year period (June 1994–May 1996) in the Northwest region of Portugal using ceramic cup samplers. The crops were grown for silage making and include maize (from May to September) and a winter crop (rest of the year)

  19. Soil precompression stress, penetration resistance and crop yields in relation to differently-trafficked, temperate-region sandy loam soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Lamandé, Mathieu; Munkholm, Lars Juhl

    2016-01-01

    . Undisturbed soil cores were used for quantifying the precompression stress (spc) of non-compacted soil. Tractor-trailer combinations for slurry application with wheel loads of 3, 6 and 8 Mg (treatments M3, M6, M8) were used for the experimental traffic in the spring at field-capacity. For one additional...

  20. Toxicity of Nitro-Heterocyclic and Nitroaromatic Energetic Materials to Folsomia candida in a Natural Sandy Loam Soil

    Science.gov (United States)

    2015-04-01

    these tests. Acetone (CAS: 67-64-1; high-performance liquid chromatography [HPLC] grade) was used for preparing EM solutions during the soil amendments... chromatography grade, purity: 99.9%) was used in the HPLC determinations. Certified standards of the energetics (AccuStandard, Inc., New Haven, CT) were used...H.; Van Gestel, C.A.M. Handbook of Soil Invertebrate Toxicity Tests; John Wiley & Sons: Hoboken, NJ, 1998. McLellan, W.L.; Hartley, W.R.; Brower

  1. Impact of industrial effluent on growth and yield of rice (Oryza sativa L.) in silty clay loam soil.

    Science.gov (United States)

    Anwar Hossain, Mohammad; Rahman, Golum Kibria Muhammad Mustafizur; Rahman, Mohammad Mizanur; Molla, Abul Hossain; Mostafizur Rahman, Mohammad; Khabir Uddin, Mohammad

    2015-04-01

    Degradation of soil and water from discharge of untreated industrial effluent is alarming in Bangladesh. Therefore, buildup of heavy metals in soil from contaminated effluent, their entry into the food chain and effects on rice yield were quantified in a pot experiment. The treatments were comprised of 0, 25%, 50%, 75% and 100% industrial effluents applied as irrigation water. Effluents, initial soil, different parts of rice plants and post-harvest pot soil were analyzed for various elements, including heavy metals. Application of elevated levels of effluent contributed to increased heavy metals in pot soils and rice roots due to translocation effects, which were transferred to rice straw and grain. The results indicated that heavy metal toxicity may develop in soil because of contaminated effluent application. Heavy metals are not biodegradable, rather they accumulate in soils, and transfer of these metals from effluent to soil and plant cells was found to reduce the growth and development of rice plants and thereby contributed to lower yield. Moreover, a higher concentration of effluent caused heavy metal toxicity as well as reduction of growth and yield of rice, and in the long run a more aggravated situation may threaten human lives, which emphasizes the obligatory adoption of effluent treatment before its release to the environment, and regular monitoring by government agencies needs to be ensured. Copyright © 2015. Published by Elsevier B.V.

  2. Study and Estimation of the Ratio of 137CS and 40K Specific Activities in Sandy and Loam Soils

    Directory of Open Access Journals (Sweden)

    Renata Mikalauskienė

    2011-12-01

    Full Text Available The present article describes changes in specific activities and fluctuations in the ratio of natural 40K and artificial 137Cs radionuclides in soil samples taken from different places of Lithuanian territory. The samples of soil have been selected from the districts polluted after the accident in Chernobyl nuclear plant performing nuclear testing operations. The study has established the main physical and chemical properties of soil samples and their impact on the concentration of 40K activities. 137Cs/40K specific activities in soil have been observed under the dry weight of the sample that varied from 0.0034 to 0.0240. The results of the study could be used for establishing and estimating 137Cs and 40K transfer in the system “soil-plant”.Article in Lithuanian

  3. Soil, crop and emission responses to seasonal-controlled traffic in organic vegetable farming on loam soil

    NARCIS (Netherlands)

    Vermeulen, G.D.; Mosquera Losada, J.

    2009-01-01

    Some organic arable and vegetable farms in the Netherlands use cm-precise guidance of machinery to restrict wheel traffic to fixed traffic lanes and to achieve non-trafficked cropping zones with optimized soil structure in between the lanes. Contrary to controlled traffic farming (CTF) the traffic

  4. Eleven years' effect of conservation practices for temperate sandy loams: I. Soil physical properties and topsoil carbon content

    DEFF Research Database (Denmark)

    Abdollahi, Lotfallah; Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl

    2017-01-01

    (D) and harrowing to a depth of 8 to 10 cm (H). Soil sampling and in-field measurements were performed in autumn 2013 and spring 2014. In the field, soil structure was visually evaluated and penetration resistance (PR) measured. Soil C, wet stability (clay dispersion and wet aggregate stability....... However, H and D in combination with residue retention gave the best structural stability. Residue retention alleviated negative effects of reduced tillage on PR and improved wet stability in the MP treatment at the Foulum site. Clay and SOC correlated well with soil physical parameters, confirming...... their important role in soil structure formation and stabilization. Our study showed benefits of combining key CA elements, although longer-term studies are most likely needed to reveal the full potential....

  5. Can mud (silt and clay) concentration be used to predict soil organic carbon content within seagrass ecosystems?

    KAUST Repository

    Serrano, Oscar; Lavery, P. S.; Duarte, Carlos M.; Kendrick, Gary A.; Calafat, Antoni; York, P.; Steven, Andy; Macreadie, Peter I.

    2016-01-01

    The emerging field of blue carbon science is seeking cost-effective ways to estimate the organic carbon content of soils that are bound by coastal vegetated ecosystems. Organic carbon (C-org) content in terrestrial soils and marine sediments has

  6. Evaluation of the concentration of heavy metals in sea water, silt and rock oysters, Crassostrea iridescens, from Manzanillo bay

    International Nuclear Information System (INIS)

    Guerrero Carbajal, Y.C.

    1993-01-01

    Some essential metals such as Fe, Ni, Cu and Zn were evaluated by X-ray spectroscopy in water, soil and rock oyster Crassostrea iridescens from Manzanillo Bay. Four samplings were taken every two months during 1991. Concentration range on liofilized oysters for Fe was determined between 76 and 172 μ g/g dry weight, Ni 9-21 μ g/g dry weight, Cu 21-123 μ g/g dry weight and Zn 216-885 μ g/g dry weight. Ni concentration was above the toxicological tolerance level for crustaceans (5 μ g/g); Cu was above maxima permission limited (MPL) from FAO for molluscs (70 μ g/g); Zn was below MPL for oysters (1000 μ g/g). For Fe there is no MPL for oyster or any other aquatic organisms. Concentration and accumulation factors for the elements measured suggested the filtration oyster activity. Fe concentration range in water was 27-2266 μ g/l. This value is above the ecological aquatic life criteria in Mexico (50 μ g/l). For Cu the concentration range was 4-536 μ g/l., which is above the MPL for Mexican Legislation (5 μ g/l). Chemical elements detected in soil were the essential metal mentioned before. However, the heavy metals concentrations for soil, from Manzanillo Bay, were higher than those reported in other polluted regions in both Mexican coasts. Concentration range for Fe was 30661-76332 μ g/g, Ni 19-180 μ g/g, Cu 56-270 μ g/g and Zn 33-1377 μ g/g. Contamination problem in Manzanillo Bay must be considered as an evidence of potential risk, since the essential metals are reaching levels that could endanger aquatic life. (Author). 87 refs, 20 figs, 6 tabs

  7. Existence of a common growth curve for silt-sized quartz OSL of loess from different continents

    International Nuclear Information System (INIS)

    Lai Zhongping; Brueckner, Helmut; Zoeller, Ludwig; Fuelling, Alexander

    2007-01-01

    Recent publications revealed different opinions regarding the existence of a common growth curve (CGC) for OSL of quartz. In the current study, 18 loess samples were collected from four continents (Asia, America, Africa, and Europe) in order to further examine this issue. Except the three samples from Chile in South America, 15 samples display similar dose-response curves up to a regeneration dose of 200 Gy using the SAR protocol, suggesting the existence of a global CGC for loess from different continents. For samples with equivalent doses (D e ) from ∼10 to ∼170Gy, the D e s determined by the CGC are in good agreement with the D e s by the SAR protocol. The Chilean samples posses a growth curve that differs from the CGC, showing much lower saturation doses. We suggest that it may be due to contamination with heavy minerals

  8. Theoretical Model for Stabilization of Clay-Silt Airport Pavement Subgrade Systems. Phase 1. Laboratory Investigation. Phase 2. Rutting Tests

    Science.gov (United States)

    1989-05-01

    size, gradation, reactivity , plasticity index, pH concentration, degree of drainage, ratio of calcium to magnesium ions, ratio of silica to...many were proprietary. The best of stabilizers include Quaternary amines, AM-9 chemical grout, phosphoric acid, lignin and cellulose derivatives, sodium...strong or weak alkalies . It is soluble in aromatic and chlorinated hydrocarbons, a strong negative factor to be considered in its candidacy as a

  9. Strength Estimation for Hydrate-Bearing Sediments From Direct Shear Tests of Hydrate-Bearing Sand and Silt

    Science.gov (United States)

    Liu, Zhichao; Dai, Sheng; Ning, Fulong; Peng, Li; Wei, Houzhen; Wei, Changfu

    2018-01-01

    Safe and economic methane gas production, as well as the replacement of methane while sequestering carbon in natural hydrate deposits, requires enhanced geomechanical understanding of the strength and volume responses of hydrate-bearing sediments during shear. This study employs a custom-made apparatus to investigate the mechanical and volumetric behaviors of carbon dioxide hydrate-bearing sediments subjected to direct shear. The results show that both peak and residual strengths increase with increased hydrate saturation and vertical stress. Hydrate contributes mainly the cohesion and dilatancy constraint to the peak strength of hydrate-bearing sediments. The postpeak strength reduction is more evident and brittle in specimens with higher hydrate saturation and under lower stress. Significant strength reduction after shear failure is expected in silty sediments with high hydrate saturation Sh ≥ 0.65. Hydrate contribution to the residual strength is mainly by increasing cohesion at low hydrate saturation and friction at high hydrate saturation. Stress state and hydrate saturation are dominating both the stiffness and the strength of hydrate-bearing sediments; thus, a wave velocity-based peak strength prediction model is proposed and validated, which allows for precise estimation of the shear strength of hydrate-bearing sediments through acoustic logging data. This method is advantageous to geomechanical simulators, particularly when the experimental strength data of natural samples are not available.

  10. Cellular effects of bacterial N-3-Oxo-dodecanoyl-L-Homoserine lactone on the sponge Suberites domuncula (Olivi, 1792): insights into an intimate inter-kingdom dialogue.

    Science.gov (United States)

    Gardères, Johan; Henry, Joël; Bernay, Benoit; Ritter, Andrès; Zatylny-Gaudin, Céline; Wiens, Matthias; Müller, Werner E G; Le Pennec, Gaël

    2014-01-01

    Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecules such as N-acyl-L-homoserine lactones, produced by Gram-negative bacteria also within sponges. In this study, we examined the role of N-3-oxododecanoyl-L-homoserine lactone (3-oxo-C12-HSL) on the expression of immune and apoptotic genes of the host sponge Suberites domuncula. This molecule seemed to inhibit the sponge innate immune system through a decrease of the expression of genes coding for proteins sensing the bacterial membrane: a Toll-Like Receptor and a Toll-like Receptor Associated Factor 6 and for an anti-bacterial perforin-like molecule. The expression of the pro-apoptotic caspase-like 3/7 gene decreased as well, whereas the level of mRNA of anti-apoptotic genes Bcl-2 Homolog Proteins did not change. Then, we demonstrated the differential expression of proteins in presence of this 3-oxo-C12-HSL using 3D sponge cell cultures. Proteins involved in the first steps of the endocytosis process were highlighted using the 2D electrophoresis protein separation and the MALDI-TOF/TOF protein characterization: α and β subunits of the lysosomal ATPase, a cognin, cofilins-related proteins and cytoskeleton proteins actin, α tubulin and α actinin. The genetic expression of some of these proteins was subsequently followed. We propose that the 3-oxo-C12-HSL may participate in the tolerance of the sponge apoptotic and immune systems towards the presence of bacteria. Besides, the sponge may sense the 3-oxo-C12-HSL as a molecular evidence of the bacterial presence and/or density in order to regulate the populations of symbiotic bacteria in the sponge. This study is the first report of a bacterial secreted molecule acting on sponge cells and regulating the symbiotic relationship.

  11. Œuvre 220 : Édouard Levé d’après Nicolas Brasseur - Entretien avec Olivier Sécardin

    Directory of Open Access Journals (Sweden)

    Olivier Sécardin

    2017-06-01

    Full Text Available Nicolas Brasseur, artiste, photographe, né en 1981 à Nantes. Vit et travaille à Paris. Diplômé de l’École Nationale Supérieure des Arts Décoratifs de Paris en 2008, Nicolas Brasseur poursuit un travail documentaire au sein d’institutions françaises autour de la notion « d’images modèles ». Ses recherches l’ont amené à photographier l’hôpital, l’école et plus récemment la prison en parte-nariat avec le Centre Photographique d’Ile-de-France (CPIF.Édouard Levé, écrivain, artiste, photographe, né en 1965, mort en 2007. Diplômé de l’ESSEC, il commence à peindre en 1991, puis brûle presque toutes ses toiles avant de se consacrer à la photographie. En 1999, il réalise sa première série, Homonymes, qui propose des portraits photographiques de personnes inconnues portant des noms célèbres : Georges Bataille, Yves Klein, Henri Michaux… Il reprend le même procédé dans Amérique (2006, reportage sur des villes américaines qui portent le nom d’autres villes connues : Florence, Berlin, Paris... Il est l’auteur de plusieurs séries photographiques. Admirateur de Raymond Roussel, lecteur de Jacques Roubaud et de Raymond Queneau, Édouard Levé est aussi écrivain. OEuvres, publié en 2002 est le catalogue de 533 projets d’oeuvres d’art, installations, peintures, sculptures ou photographies imaginés dont l’artiste a « eu l’idée, mais qu’il n’a pas réalisés ». Son Autoportrait le présente en « 1600 phrases sans solution de continuité ». Trois jours avant de se donner la mort, Édouard Levé dépose chez son éditeur le manuscrit de son dernier texte, Suicide (2008.

  12. The gas crisis and South-East Europe. Review (in english) of the 'Mardi de l'IFRI' with Olivier Silla in Brussels, 10 March 2009

    International Nuclear Information System (INIS)

    Nardon, L.

    2009-01-01

    In the gas crisis of January 2009, South-East Europe (SEE) was probably the region most impacted. It was therefore interesting to analyze how the region's energy sector and policy makers reacted and which lessons can be drawn from these days. It is pointed that SEE has a relatively low utilization of gas, but most countries in the region are highly dependent on one single supplier, Gazprom. Overall gas consumption in SEE is very limited in absolute terms and gas use is limited to industry and district heating in most cases. With the exception of Greece, and for a small part Croatia, gas is not used for electricity production in SEE, lessening the impact of the supply disruption for the region. Gas reaches the region via three main pipeline branches that all go through Ukraine but are not inter-linked (hence no possibility to bring gas from one branch to another). For the overall coordination and cooperation in the energy sector, the Energy Community plays an important role in SEE. Set up in 2006, it provides a flexible framework and helps reforming the region's energy sector. In the context of the Energy Community, SEE countries are obliged to introduce the EU attainments on energy. Moreover, the Energy Community also foresees ambitious goals for regional solidarity

  13. "In the Wake of the Crisis : Leading Economists Reassess Economic Policy" Edited by Olivier Blanchard, David Romer, Michael Spence, and Joseph Stiglitz

    OpenAIRE

    Murat Ungor

    2013-01-01

    To understand the issues raised by the recent global crisis, IMF organized a conference on March 7-8, 2011, around six themes: monetary policy, fiscal policy, financial intermediation and regulation, capital account management, growth strategies, and the international monetary system. The conference proceedings are published in a book, In the Wake of the Crisis: Leading Economists Reassess Economic Policy. This review presents a summary of the book and provides its implications for research a...

  14. Inherited Sterility of Fl Male Sitotroga cerealella (Olivier) and changes in the DNA Pattern as a Result of Using Gamma irradiation

    International Nuclear Information System (INIS)

    Rizk, S.A.; Mikhaiel, A.A.

    2009-01-01

    Full grown pupae of the Angoumois grain moth, Sitotroga cerealella were irradiated with 75 and 175 Gy or gamma irradiation .The sterility percent was increased by increasing of' gamma irradiation dose. Also, the sterility percent increased in F 1 males than in parents. Gamma irradiation caused a decrease in size or the ova doles and number of oocytes. The effects of gamma rays on the DNA patterns of adult male parents and Fl males showed alterations among the controls, the treated parents and Ft individuals. Exposure to radiation caused very frequently the appearance of some extra bands and the deficiency of others in the RAPD-PCR amplification patterns of the irradiated insects. However, the similarity in DNA patterns between some normal and treated samples was interpreted by assuming, that the radiation induced damage was in regions of' the genome other than at the loci under study

  15. Distribución y caracterización morfológica de Hycleus duodecimmaculatus (Olivier, 1811 (Coleoptera, Meloidae, una especie poco conocida del oeste de Marruecos

    Directory of Open Access Journals (Sweden)

    Ruiz, José L.

    2014-06-01

    Full Text Available Hycleus duodecimmaculatus (Coleoptera, Meloidae, Mylabrini is a poorly known species endemic to Morocco. Its geographic range extends along the coastal-subcoastal fringe of the Atlantic Coast, between Larache and Tiznit region (Arbaa Ait Ahmed. In this paper we study more than a hundred specimens, mostly preserved in the collection of the Museo Nacional de Ciencias Naturales (MNCN-CSIC, Spain. We provide new geographic records, including the Western Rif and confirm its presence in Marrakech (northwestern slopes of the High Atlas. Because of the scarcity of information, disperse and sometimes erroneous, we synthesize information available on chorology and phenology, and characterize the typology of the species’ habitat. From a taxonomic point of view, we redefine the species’ diagnostic characters and illustrate various aspects of the intra- and interpopulational morphological variability.Hycleus duodecimmaculatus (Coleoptera, Meloidae, Mylabrini es un endemismo de Marruecos muy poco conocido, cuya distribución se extiende por la franja costera-subcostera del Marruecos atlántico, entre Larache y la región de Tiznit (Arbaa Ait Ahmed. En este trabajo, realizado principalmente a partir del estudio de más de un centenar de ejemplares conservados en su mayor parte en la colección del Museo Nacional de Ciencias Naturales (MNCN-CSIC, España, se aportan nuevas citas geográficas incluyendo el Rif occidental, y se confirma su presencia en Marrakech (falda noroccidental del Alto Atlas. A la vista de la escasez de información existente para esta especie, dispersa y a veces errónea, se sintetiza la información corológica disponible, y se ofrecen datos sobre fenología de los adultos y tipología general de los hábitats que ocupa. Desde el punto de vista taxonómico, se redefinen los caracteres diagnósticos de la especie y se ilustran diversos aspectos de la variabilidad morfológica intra e interpoblacional.

  16. Cellular effects of bacterial N-3-Oxo-dodecanoyl-L-Homoserine lactone on the sponge Suberites domuncula (Olivi, 1792: insights into an intimate inter-kingdom dialogue.

    Directory of Open Access Journals (Sweden)

    Johan Gardères

    Full Text Available Sponges and bacteria have lived together in complex consortia for 700 million years. As filter feeders, sponges prey on bacteria. Nevertheless, some bacteria are associated with sponges in symbiotic relationships. To enable this association, sponges and bacteria are likely to have developed molecular communication systems. These may include molecules such as N-acyl-L-homoserine lactones, produced by Gram-negative bacteria also within sponges. In this study, we examined the role of N-3-oxododecanoyl-L-homoserine lactone (3-oxo-C12-HSL on the expression of immune and apoptotic genes of the host sponge Suberites domuncula. This molecule seemed to inhibit the sponge innate immune system through a decrease of the expression of genes coding for proteins sensing the bacterial membrane: a Toll-Like Receptor and a Toll-like Receptor Associated Factor 6 and for an anti-bacterial perforin-like molecule. The expression of the pro-apoptotic caspase-like 3/7 gene decreased as well, whereas the level of mRNA of anti-apoptotic genes Bcl-2 Homolog Proteins did not change. Then, we demonstrated the differential expression of proteins in presence of this 3-oxo-C12-HSL using 3D sponge cell cultures. Proteins involved in the first steps of the endocytosis process were highlighted using the 2D electrophoresis protein separation and the MALDI-TOF/TOF protein characterization: α and β subunits of the lysosomal ATPase, a cognin, cofilins-related proteins and cytoskeleton proteins actin, α tubulin and α actinin. The genetic expression of some of these proteins was subsequently followed. We propose that the 3-oxo-C12-HSL may participate in the tolerance of the sponge apoptotic and immune systems towards the presence of bacteria. Besides, the sponge may sense the 3-oxo-C12-HSL as a molecular evidence of the bacterial presence and/or density in order to regulate the populations of symbiotic bacteria in the sponge. This study is the first report of a bacterial secreted molecule acting on sponge cells and regulating the symbiotic relationship.

  17. Efficacy of aggregation pheromone in trapping red palm weevil (Rhynchophorus ferrugineus Olivier) and rhinoceros beetle (Oryctes rhinoceros Linn.) from infested coconut palms.

    Science.gov (United States)

    Chakravarthy, A K; Chandrashekharaiah, M; Kandakoor, Subhash B; Nagaraj, D N

    2014-05-01

    Red palm weevil and Rhinoceros beetle are the major pests inflicting severe damage to coconut palms. Due to ineffectiveness of the current management practices to control the two important pests on coconut, a study was conducted to know the attractiveness of red palm weevil and rhinoceros beetle to aggregation pheromone. Olfactometer studies indicated that the aggregation pheromone of red palm weevil and rhinoceros beetle attracted significantly more number of weevils (13.4 females and 7.6 male weevils) and beetles (6.5 male and 12.3 female beetles), respectively than control. Similarly, field studies found that both 750 and 1000 mg pheromone dosage lures of red palm weevil and rhinoceros beetle trapped significantly higher numbers of weevils (695.80 and 789 weevils, respectively) and beetles (98 and 108 beetles, respectively) in traps (P rhinoceros beetle population got trapped. Observations indicated activity of red palm weevil throughout the year and of rhinoceros beetle from September to March around Bangalore, South India. Pheromone traps for red palm weevil can be placed in fields from June to August and October to December and September to February for rhinoceros beetle. Population reductions of the two coleopteran pests by pheromone traps are compatible with mechanical and cultural management tools with cumulative effects.

  18. The fate of uranium contaminants of phosphate fertiliser: chemical partitioning of uranium in two New Zealand soils of volcanic origin and the effect on partitioning of amending one of those soils with uranium

    International Nuclear Information System (INIS)

    Taylor, M.D.

    1998-01-01

    This study assessed the chemical partitioning of U isotopes in Horomanga Sandy Loam and Te Kowhai silt loam, two agricultural soils derived from rhyolitic ash and receiving low level contamination from U impurities in phosphate fertiliser. To simulate future U additions, a sub-sample of the Horomanga soil was amended with 2.259 μg U g -1 soil before sequential extraction. The hypothesis that U additions will be strongly held on to the soil and are not available for leaching or plant uptake was tested. After extraction U was purified and determined by alpha spectrometry. Results were corrected for tailing, background, for losses in the purification process (using 232 U), and for soil moisture. It is concluded that only a small proportion of U in the two type of soils examined was derived from fertiliser and that very little U would be available to plants or to leaching

  19. Field Soil Water Retention of the Prototype Hanford Barrier and Its Variability with Space and Time

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z. F.

    2015-08-14

    Engineered surface barriers are used to isolate underlying contaminants from water, plants, animals, and humans. To understand the flow processes within a barrier and the barrier’s ability to store and release water, the field hydraulic properties of the barrier need to be known. In situ measurement of soil hydraulic properties and their variation over time is challenging because most measurement methods are destructive. A multiyear test of the Prototype Hanford Barrier (PHB) has yielded in situ soil water content and pressure data for a nine-year period. The upper 2 m layer of the PHB is a silt loam. Within this layer, water content and water pressure were monitored at multiple depths at 12 water balance stations using a neutron probe and heat dissipation units. Valid monitoring data from 1995 to 2003 for 4 depths at 12 monitoring stations were used to determine the field water retention of the silt loam layer. The data covered a wide range of wetness, from near saturation to the permanent wilt point, and each retention curve contained 51 to 96 data points. The data were described well with the commonly used van Genuchten water retention model. It was found that the spatial variation of the saturated and residual water content and the pore size distribution parameter were relatively small, while that of the van Genuchten alpha was relatively large. The effects of spatial variability of the retention properties appeared to be larger than the combined effects of added 15% w/w pea gravel and plant roots on the properties. Neither of the primary hydrological processes nor time had a detectible effect on the water retention of the silt loam barrier.

  20. Loss of surface horizon of an irrigated soil detected by radiometric images of normalized difference vegetation index.

    Science.gov (United States)

    Fabian Sallesses, Leonardo; Aparicio, Virginia Carolina; Costa, Jose Luis

    2017-04-01

    The use of the soil in the Humid Pampa of Argentina has changed since the mid-1990s from agricultural-livestock production (that included pastures with direct grazing) to a purely agricultural production. Also, in recent years the area under irrigation by central pivot has been increased to 150%. The waters used for irrigation are sodium carbonates. The combination of irrigation and rain increases the sodium absorption ratio of soil (SARs), consequently raising the clay dispersion and reducing infiltration. This implies an increased risk of soil loss. A reduction in the development of white clover crop (Trifolium repens L.) was observed at an irrigation plot during 2015 campaign. The clover was planted in order to reduce the impact of two maize (Zea mays L.) campaigns under irrigation, which had increased soil SAR and deteriorated soil structure. SPOT-5 radiometric normalized difference vegetation index (NDVI) images were used to determine two zones of high and low production. In each zone, four random points were selected for further geo-referenced field sampling. Two geo-referenced measures of effective depth and surface soil sampling were carried out in each point. Texture of soil samples was determined by Pipette Method of Sedimentation Analysis. Data exploratory analysis showed that low production zone had a media effective depth = 80 cm and silty clay loam texture, while high production zone had a media effective depth > 140 cm and silt loam texture. The texture class of the low production zone did not correspond to prior soil studies carried out by the INTA (National Institute of Agricultural Technology), which showed that those soil textures were silt loam at surface and silty clay loam at sub-surface. The loss of the A horizon is proposed as a possible explanation, but further research is required. Besides, the need of a soil cartography actualization, which integrates new satellite imaging technologies and geo-referenced measurements with soil sensors is

  1. Integrated assessment of space, time, and management-related variability of soil hydraulic properties

    Energy Technology Data Exchange (ETDEWEB)

    Es, H.M. van; Ogden, C.B.; Hill, R.L.; Schindelbeck, R.R.; Tsegaye, T.

    1999-12-01

    Computer-based models that simulate soil hydrologic processes and their impacts on crop growth and contaminant transport depend on accurate characterization of soil hydraulic properties. Soil hydraulic properties have numerous sources of variability related to spatial, temporal, and management-related processes. Soil type is considered to be the dominant source of variability, and parameterization is typically based on soil survey databases. This study evaluated the relative significance of other sources of variability: spatial and temporal at multiple scales, and management-related factors. Identical field experiments were conducted for 3 yr. at two sites in New York on clay loam and silt loam soils, and at two sites in Maryland on silt loam and sandy loam soils, all involving replicated plots with plow-till and no-till treatments. Infiltrability was determined from 2054 measurements using parameters, and Campbell's a and b parameters were determined based on water-retention data from 875 soil cores. Variance component analysis showed that differences among the sites were the most important source of variability for a (coefficient of variation, CV = 44%) and b (CV = 23%). Tillage practices were the most important source of variability for infiltrability (CV = 10%). For all properties, temporal variability was more significant than field-scale spatial variability. Temporal and tillage effects were more significant for the medium- and fine-textured soils, and correlated to initial soil water conditions. The parameterization of soil hydraulic properties solely based on soil type may not be appropriate for agricultural lands since soil-management factors are more significant. Sampling procedures should give adequate recognition to soil-management and temporal processes at significant sources of variability to avoid biased results.

  2. Application of Polyacrylamide (PAM) through Lay-Flat Polyethylene Tubing: Effects on Infiltration, Erosion, N and P Transport, and Corn Yield.

    Science.gov (United States)

    McNeal, J P; Krutz, L J; Locke, M A; Kenty, M M; Atwill, R L; Pickelmann, D M; Bryant, C J; Wood, C W; Golden, B R; Cox, M S

    2017-07-01

    Polyacrylamides (PAMs), when applied as a soil amendment, purportedly improve soil infiltration, decrease erosion, and reduce offsite agrochemical transport. The effect of PAM on infiltration, erosion, agrochemical transport, and crop yield when applied in furrow to mid-southern US production systems has not been evaluated. The objective of this study was to assess PAM effects on infiltration, erosion, corn ( L.) grain yield, and nitrogen (N) and phosphorus (P) transport when applied at 10 mg L through lay-flat polyethylene tubing. A 2-yr field study was conducted at the Mississippi State Delta Research and Extension Center in Stoneville, MS, on a Dundee silt loam and a Forestdale silty clay loam. The experimental design was a randomized complete block with four replications of each treatment: irrigated plus no PAM (control) and irrigated plus PAM at 10 mg L. Each irrigation event delivered 102 mm of water at 18.9 L m per furrow, and runoff was captured in a holding tank on the lower end of each plot. Pooled over year and soil texture, PAM increased infiltration and corn grain yield by 6% ( ≤ 0.0398). Polyacrylamide effects on the offsite transport of sediment and N and P were inconsistent, varying across year and soil texture. Results indicate that PAM improves infiltration and corn grain yield on silt loam and silty clay loam textured soils; however, further research is required before PAM can be recommended as a best management practice for mitigating erosion and offsite agrochemical transport in mid-southern production systems. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Isotope studies on the comparative efficiency of nitrogenous sources

    Energy Technology Data Exchange (ETDEWEB)

    Dev, G; Rennie, D A [Saskatchewan Univ., Saskatoon (Canada). Dept. of Soil Science

    1979-03-01

    In a growth chamber experiment with /sup 15/N-labelled potassium nitrate, ammonium sulphate and urea at 75 and 150kg nitrogen/ha and ammonium nitrate at 150kg nitrogen/ha, nitrogen application produced significant responses of dry matter yield and total nitrogen uptake by shoot and root of barley in chernozemic dark brown Elstow silt loam and deep black Hoey clay soil. Total nitrogen removal per pot and isotope-derived criteria, viz. percentage nitrogen derived from fertilizer, 'A' value and percentage fertilizer nitrogen utilization, indicated that potassium nitrate was the most efficient and urea the least.

  4. Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

    OpenAIRE

    Kuo, S.; Huang, B.; Bembenek, R.

    2001-01-01

    Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3 leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation sin...

  5. An analysis on remediation characteristics of soils contaminated with Co for in-situ application

    International Nuclear Information System (INIS)

    Kim, K. N.; Won, H. J.; Kweun, H. S.; Shon, J. S.; Oh, W. J.

    1999-01-01

    The solvent flushing apparatus for in-situ soil remediation was designed. After the soil around nuclear facilities was sampled and compulsorily contaminated by Co solution, the remediation characteristics by solvent flushing were analyzed. Meanwhile, the nonequilibrium sorption code was developed for modelling of the soil remediation by solvent flushing, and input parameters needed for modelling were measured by laboratory experiment. Experimental results are as follows: The soil around nuclear facilities belongs to Silt Loam including a lot of silt and sand. When water was used as a solvent, the higher was the hydraulic conductivity, the higher the efficiency of soil remediation was. The values calculated by the nonequilibrium sorption code agreed with experimental values more exactly than the values calculated by the equilibrium sorption code. When citric acid was used as a solvent, the soil remediation efficiency by citric acid showed 1.65 times that by water

  6. Infestação por larvas de Cerotoma arcuata (Olivier (Coleoptera: Chrysomelidae em nódulos de feijoeiro em cultivo com cobertura morta ou em consórcio com milho ou com caupi Infestation by Cerotoma arcuata (Olivier (Coleoptera: Chrysomelidae larvae on Phaseolus bean with mulching or intercropped with maize or cowpea

    Directory of Open Access Journals (Sweden)

    Maria Lucia França Teixeira

    2007-12-01

    Full Text Available A vaquinha Cerotoma arcuata ataca folhas de leguminosas e suas larvas alimentam-se de raízes e também de nódulos, onde a fixação de nitrogênio (FBN ocorre. O ataque das larvas aos nódulos pode causar mais danos à cultura do feijoeiro do que o consumo das folhas pelas formas adultas. Este estudo foi conduzido em condições de campo para avaliar os efeitos da infestação de C. arcuata no cultivo do feijoeiro com ou sem cobertura morta ou consorciado com caupi ou com milho. A nodulação, o crescimento e a produção de grãos de feijoeiro quando consorciado com caupi não diferiram do controle. A barreira aos insetos formada pelo milho adensado falhou, provavelmente devido à infestação precoce de C. arcuata e ao sombreamento causado pelo milho, com redução na produtividade de feijoeiro. O consumo dos nódulos pelas larvas na cultura de feijão solteiro e nos consórcios foi superior ao do tratamento com cobertura morta. A barreira física imposta pela cobertura morta agiu provavelmente através da redução da oviposição diretamente no solo e do ressecamento dos ovos sobre a palha e resultou em menor porcentagem de nódulos furados, com conseqüente aumento no número e peso de nódulos, no peso de raiz e na produção de grãos. Os consórcios com milho ou com caupi não reduziram a infestação de feijoeiro por C. arcuata, mas a aplicação da cobertura morta antes da infestação reduziu os danos causados pelas larvas aos nódulos e favoreceu a FBN e a produtividade.The bean leaf beetle Cerotoma arcuata is a legume leaf eater and its larvae feed on roots and also nodules where nitrogen fixation occurs. The attack of larvae to nodule may result in more damage to the bean crop than the consumption of leaves by adults. This study was conducted under field conditions to test the effects of C. arcuata infestation on Phaseolus bean with or without straw mulching or intercropped with maize or cowpea. Nodulation, growth and grain production when intercropping with cowpea did not differ from the control. The insect barrier formed by the maize’s high density failed, probably due to the early infestation by C. arcuata, as well as shading by the rows of maize, thereby reducing grain yield. Consumption of nodules was higher on the Phaseolus bean with or without intercropping than on the treatment with straw mulching. The physical barrier imposed by straw mulch probably acted by reducing oviposition directly on soil and drying the eggs laid above the straw, resulting in a smaller percentage of punctured nodules and consequently increasing nodule number and dry weight, root dry weight and grain yields. Intercropping with maize and cowpea did not reduce Phaseolus bean infestation by C. arcuata but straw mulching applied before infestation reduced damage caused by larvae to the nodules, increasing N2 fixation and grain yields.

  7. Susceptibilidade de larvas de Cerotoma arcuata Olivier (Coleoptera: Chrysomelidae a Beauveria bassiana (Bals. Vuillemin, Metarhizium anisopliae (Metsch. Sorokin e Bacillus thuringiensis Berliner Susceptibility of Cerotoma arcuata Olivier (Coleoptera: Chrysomelidae larvae to Beauveria bassiana (Bals. Vuillemin, Metarhizium anisopliae (Metsch. Sorokin and Bacillus thuringiensis Berliner

    Directory of Open Access Journals (Sweden)

    Maria Lucia França Teixeira

    2007-02-01

    Full Text Available Larvas de 2° instar de Cerotoma arcuata foram avaliadas em relação à susceptibilidade aos fungos entomopatogênicos Beauveria bassiana, Metarhizium anisopliae e a bactéria Bacillus thuringiensis com as toxinas Cry3. Os insetos adultos foram mantidos em gaiolas e alimentados com plântulas de feijão (Phaseolus vulgaris L. e as larvas em "gerbox" com cotilédones de plântulas de feijão recém-germinadas. Das oito estirpes de B. bassiana avaliadas, CG 156 e CG 213 causaram 100% de mortalidade das larvas, as duas estirpes de M. anisopliae CG 210 e CG 321 foram patogênicas, eliminando 80 e 100% das larvas de C. arcuata, e, das cinco estirpes de B. thuringiensis testadas, o isolado CG 940 causou 70% de mortalidade das larvas.Second instar larvae of Cerotoma arcuata were evaluated concerning the susceptibility to fungi Beauveria bassiana and Metarhizium anisopliae and Bacillus thuringiensis strains containing Cry3 toxin. Adults of C. arcuata were kept in large cages and fed on bean seedlings and the larvae were reared in ‘gearbox’ feeding on germinated Phaseolus bean cotyledons. Strains CG 156 and CG 213 of B. bassiana killed 100% of the insect larvae and strains CG 210 and CG 321 of M. anisopliae killed 80 and 100% of the insect larvae. Strain CG 940 of B. thuringiensis killed 70% of the insect larvae.

  8. The gas crisis and South-East Europe. Review (in english) of the 'Mardi de l'IFRI' with Olivier Silla in Brussels, 10 March 2009; La crise gaziere et l'Europe du Sud-Est - Compte-rendu (en anglais) du mardi de l'Ifri autour de Olivier Silla a Bruxelles le 10 Mars 2009

    Energy Technology Data Exchange (ETDEWEB)

    Nardon, L.

    2009-07-01

    In the gas crisis of January 2009, South-East Europe (SEE) was probably the region most impacted. It was therefore interesting to analyze how the region's energy sector and policy makers reacted and which lessons can be drawn from these days. It is pointed that SEE has a relatively low utilization of gas, but most countries in the region are highly dependent on one single supplier, Gazprom. Overall gas consumption in SEE is very limited in absolute terms and gas use is limited to industry and district heating in most cases. With the exception of Greece, and for a small part Croatia, gas is not used for electricity production in SEE, lessening the impact of the supply disruption for the region. Gas reaches the region via three main pipeline branches that all go through Ukraine but are not inter-linked (hence no possibility to bring gas from one branch to another). For the overall coordination and cooperation in the energy sector, the Energy Community plays an important role in SEE. Set up in 2006, it provides a flexible framework and helps reforming the region's energy sector. In the context of the Energy Community, SEE countries are obliged to introduce the EU attainments on energy. Moreover, the Energy Community also foresees ambitious goals for regional solidarity

  9. Fuel consumption of tractor for different soil types in semi-arid regions; Consumo de combustivel de um trator agricola para diferentes tipos de solo em regioes semi-aridas

    Energy Technology Data Exchange (ETDEWEB)

    Montanha, Gustavo K. [Universidade Estadual Paulista (FAC/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], E-mail: gmontanha@fca.unesp.br; Guerra, Saulo P.S. [Universidade Estadual Paulista (UNESP), Botucatu, SP (Brazil). Dept. de Gestao e Tecnologia Agroindustrial; Andrade-Sanchez, Pedro; Heun, John [The University of Arizona, Maricopa, AZ (United States); Monteiro, Leonardo A. [The University of Arizona (MAC/UA), Maricopa, AZ (United States). Maricopa Agricultural Center

    2010-07-01

    The appropriate use of agricultural machinery enables greater operational efficiency and higher productivity for the farmer. Some factors such as soil type can influence the fuel consumption, one of the biggest costs. This study aimed to compare the fuel consumption of a tractor operating in two different conditions of soil in semi-arid regions. The area used for testing is located in the city of Maricopa, in Arizona, belonging to 'The University of Arizona'. The area 1 is classified as sandy clay loam soil (52% sand, 35% clay, 13% silt). The area 2 is classified as a sandy loam soil (71% sand, 12% clay and 17% silt). The tractor 4 x 2 TDA, with 88 kw (120 hp) engine power equipped with auto pilot system and an implement for tillage were used in the experiment. A data acquisition system was installed in the tractor to collect the data generated by the GPS and fuel consumption sensor. The results showed significant statistical difference in fuel consumption between soil textures. (author)

  10. Extraction of soil solution by drainage centrifugation-effects of centrifugal force and time of centrifugation on soil moisture recovery and solute concentration in soil moisture of loess subsoils.

    Science.gov (United States)

    Fraters, Dico; Boom, Gerard J F L; Boumans, Leo J M; de Weerd, Henk; Wolters, Monique

    2017-02-01

    The solute concentration in the subsoil beneath the root zone is an important parameter for leaching assessment. Drainage centrifugation is considered a simple and straightforward method of determining soil solution chemistry. Although several studies have been carried out to determine whether this method is robust, hardly any results are available for loess subsoils. To study the effect of centrifugation conditions on soil moisture recovery and solute concentration, we sampled the subsoil (1.5-3.0 m depth) at commercial farms in the loess region of the Netherlands. The effect of time (20, 35, 60, 120 and 240 min) on recovery was studied at two levels of the relative centrifugal force (733 and 6597g). The effect of force on recovery was studied by centrifugation for 35 min at 117, 264, 733, 2932, 6597 and 14,191g. All soil moisture samples were chemically analysed. This study shows that drainage centrifugation offers a robust, reproducible and standardised way for determining solute concentrations in mobile soil moisture in silt loam subsoils. The centrifugal force, rather than centrifugation time, has a major effect on recovery. The maximum recovery for silt loams at field capacity is about 40%. Concentrations of most solutes are fairly constant with an increasing recovery, as most solutes, including nitrate, did not show a change in concentration with an increasing recovery.

  11. Effect of urea placement on leaching losses of nitrogen from flooded rice soils

    International Nuclear Information System (INIS)

    Vlek, P.L.G.; Byrnes, B.H.; Craswell, E.T.

    1980-01-01

    In an effort to provide an explanation for the reported variability in fertilizer N efficiency from deep-placed urea on flooded rice, a set of controlled experiments was conducted to evaluate the effect of water percolation on fertilizer loss and plant uptake from 15 N labeled urea supergranules. Three soils of different texture (silt loam-clay) were subjected to various percolation rates (0-20 mm/day) while planted to rice which was harvested after approximately 40 days. The results indicate that moderate to high percolation through silt loam soil will lead to significant fertilizer N losses and drastically decrease the fertilizer uptake by plants. The permeability of the clay soil was too low for any leaching to take place. It is therefore concluded that deep placement of urea supergranules not be recommended in soils where percolation rates may exceed 5 mm/day, particularly if the cation exchange capacity of the soil is low. This experiment points to the need of evaluating and reporting the percolation rates in soils where experiments with supergranular urea are conducted. (orig.)

  12. Adsorption and diffusion of plutonium in soil

    International Nuclear Information System (INIS)

    Relyea, J.F.; Brown, D.A.

    1978-01-01

    The behavior of plutonium in soil--water systems was studied by measuring its apparent diffusion coefficient in the aqueous and solid phases and by finding the adsorption--desorption relationships between soil and solution. Apparent diffusion coefficients of plutonium in soil were measured using a quick-freeze method. Aqueous diffusion was studied in a capillary-tube diffusion cell. Adsorption studies were done by equilibrating a tagged soil--water mixture on a rotary shaker before centrifuging and sampling. As expected from high adsorption coefficients (Kd) (300--10,000), the apparent diffusion coefficients were low compared with normal soil cations (1.4 x 10 -8 cm 2 /sec in a sandy soil to less than 2.4 x 10 -11 cm 2 /sec in a silt loam). The Kd of plutonium in aqueous solution containing the chelate ethylenediaminetetraacetic acid (EDTA) was reduced compared with the Kd in dilute HNO 3 . As the EDTA concentration was increased, the Kd was decreased. The chelate diethylenetriaminepentaacetic acid (DTPA) reduced the Kd more than EDTA at comparable concentrations. The aqueous diffusion coefficients varied from 3.1 x 10 -7 cm 2 /sec in a solution extracted from the silt loam up to 2.7 x 10 -5 cm 2 /sec in a solution extracted from the sandy soil

  13. Geoelectrical Soil Properties of Farmlands Located on Ancient River Floodplains in EL Paso County Texas

    Science.gov (United States)

    Pegues, J. G.; Kaip, G.; Doser, D. I.

    2013-12-01

    Farming in Rio Grande flood plain deposit soils has presented challenges concerning soil salinity, soil drainage and soil collapse. Typical soil forms include Saneli silted clay loam, Harkey loam, Harkey silky loam clay and Tigua silty clay. In the lower valley farmlands of Socorro, TX, cotton and alfalfa are the principal crops, but grain sorghum, corn and vegetable crops also are suitable. Pecan trees, as well as fruit trees suited to the climate, can be grown. Agrarians are faced with varying results of crop yields over relatively small stretches of land; for example, a 22 acre area can contain multiple soil inclusions. This study was conducted on a 22 acre tract of farmland which has recently undergone multiple geophysical testing analyses that include: magnetics, DC resistivity, gravity, and ground penetrating radar. Results will compare flood plain sedimentation qualities to agricultural soil classes through the identification of soil salinity and grain size. This investigation will focus on the testing of geo-electrical soil properties through resistivity assessment. Examination of the sight using a capacity coupled resistivity meter to measure the soil properties over various time periods will be conducted. The results will be compared with the other geophysical data to look for correlations that highlight soil properties.

  14. Impact of pulp and paper mill effluents and solid wastes on soil mineralogical and physicochemical properties.

    Science.gov (United States)

    Adhikari, Gopi; Bhattacharyya, Krishna G

    2015-03-01

    The present study was carried out to evaluate the impact of the effluents and the solid wastes generated by a giant pulp and paper mill in the northeastern part of India on soil mineralogy of the area. The impacts were monitored by analysis of soil samples from seven sites located in the potential impact zone and a control site where any kind of effluent discharge or solid waste dumping was absent. The soil belonged to medium texture type (sandy clay loam, sandy loam, loamy sand, and silt loam), and the soil aggregate analysis indicated higher levels of organic carbon, pH, electrical conductivity, effective cation exchange capacity, and mean weight diameter at sites receiving effluents and solid wastes from the pulp and paper mill. Depletion in soil silica level and in feldspar and quartz contents and rise in iron and calcium contents at the sites receiving effluents from the pulp and paper mill indicated significant influence on soil mineralogy. The soil contained a mixture of minerals consisting of tectosilicates (with silicate frameworks as in quartz or feldspar), phylosilicates (layered clays like kaolinite, smectite, chlorite, illite, etc.), and carbonates. Absence of pure clay minerals indicated a state of heterogeneous intermediate soil clay transformation. The significance of the mixed mineralogy in relation to the disposal of effluents and dumping of solid wastes is discussed in details.

  15. Key parameters in testing biodegradation of bio-based materials in soil.

    Science.gov (United States)

    Briassoulis, D; Mistriotis, A

    2018-05-05

    Biodegradation of plastics in soil is currently tested by international standard testing methods (e.g. ISO 17556-12 or ASTM D5988-12). Although these testing methods have been developed for plastics, it has been shown in project KBBPPS that they can be extended also to lubricants with small modifications. Reproducibility is a critical issue regarding biodegradation tests in the laboratory. Among the main testing variables are the soil types and nutrients available (mainly nitrogen). For this reason, the effect of the soil type on the biodegradation rates of various bio-based materials (cellulose and lubricants) was tested for five different natural soil types (loam, loamy sand, clay, clay-loam, and silt-loam organic). It was shown that use of samples containing 1 g of C in a substrate of 300 g of soil with the addition of 0.1 g of N as nutrient strongly improves the reproducibility of the test making the results practically independent of the soil type with the exception of the organic soil. The sandy soil was found to need addition of higher amount of nutrients to exhibit similar biodegradation rates as those achieved with the other soil types. Therefore, natural soils can be used for Standard biodegradation tests of bio-based materials yielding reproducible results with the addition of appropriate nutrients. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. Sorption – desorption of imidacloprid insecticide on Indian soils of five different locations

    Directory of Open Access Journals (Sweden)

    Shailendra Singh Chauhan

    2013-07-01

    Full Text Available Sorption-desorption processes govern the movement of all chemicals including pesticides in soils. The present investigation was undertaken to study the sorption-desorption of imidacloprid, using a batch method, on soils of five different location of India. Sorption data were fitted to Freundlich isotherm. The log K value was the highest for loam type soil (1.830 and the lowest for clay type soil (1.661. The value of 1/n was the maximum for silt loam soil (0.909 but minimum for loam soil (0.723. Simple correlation analysis indicated that among soil properties only electrical conductivity showed a higher but marginally non-significant negative correlation with log K (r = -0.826 indicating that higher concentration of solutes solutes are conducive to low sorption capacity of soil. The desorption data conformed to two surfaces Freundlich desorption isotherm. The values of 1/n1' corresponding to easily desorbed fraction of imidacloprid showed significant negative correlation with soil pH (r = -0.886, significant at p ≤0.05 but significant positive correlation with clay content (r = 0.980, significant at p ≤0.01. The desorption index for easily desorbed fraction of imidacloprid (n1’/n also had significant negative correlation with soil pH (r = 0.953, significant at p ≤0.05. From cumulative desorption data, it appeared that bioavailability of imidacloprid would be lower in neutral soil than acidic or alkaline soils.

  17. Evaluation of soil fertility status of Regional Agricultural Research Station, Tarahara, Sunsari, Nepal

    Directory of Open Access Journals (Sweden)

    Dinesh Khadka

    2017-10-01

    Full Text Available Soil fertility evaluation of an area or region is most basic decision making tool for the sustainable soil nutrient management. In order to evaluate the soil fertility status of the Regional Agricultural Research Station (RARS, Tarahara, Susari, Nepal. Using soil sampling auger 81 soil samples (0-20 cm were collected based on the variability of land. The collected samples were analyzed for their texture, structure, colour, pH, OM, N, P2O5, K2O, Ca, Mg, S, B, Fe, Zn, Cu and Mn status. The Arc-GIS 10.1 software was used for the preparation of soil fertility maps. The soil structure was granular to sub-angular blocky and varied between brown- dark grayish brown and dark gray in colour. The sand, silt and clay content were 30.32±1.4%, 48.92±0.89% and 20.76±0.92%, respectively and categorized as loam, clay loam, sandy loam, silt loam and silty clay loam in texture. The soil was moderately acidic in pH (5.98±0.08. The available sulphur (2.15±0.21 ppm, available boron (0.08±0.01 ppm and available zinc (0.35±0.03 ppm status were very low, whereas extractable magnesium (44.33±6.03 ppm showed low status. Similarly, organic matter (2.80±0.07%, total nitrogen (0.09±0.004 %, extractable calcium (1827.90±45.80 ppm and available copper (1.15±0.04 ppm were medium in content. The available phosphorus (39.77±5.27 ppm, extractable potassium (134.12±4.91 ppm, and available manganese (18.15±1.15 ppm exhibits high status, while available iron (244.7±19.70 ppm was very high. The fertilizer recommendation can be done based on determined soil fertility status to economize crop production. Furthermore, research farm should develop future research strategy accordance with the prepared soil data base.

  18. Hibiscus sabdariffa L

    African Journals Online (AJOL)

    TEKWA IJASINI JOHN

    P application increased K and Mg, but reduced Ca contents of shoots. Application of P did ... of natural coloring and flavoring agent in food and fruit processing industries (Mc Clintock, 2004). The seeds .... loam. Loam. Sandy loam Clay loam.

  19. Analysis of some parameters related to the hydraulic infiltration of a silty-loam soil subjected to organic and mineral fertilizer systems in Southern Italy

    Directory of Open Access Journals (Sweden)

    Antonietta Napolitano

    2011-05-01

    Full Text Available This experiment was carried out to detect the most linear process to calculate the hydraulic conductivity, with the aim to classify the soil of experimental station of the Unit for Research in Cultivations Alternative to Tobacco (CAT, locate in South Italy (Scafati, Province of Salerno, subject to different types of manure: compost and mineral fertilizer. The field tests were made by a system measuring infiltration by double, inner and outer ring, inserted into the ground. Each ring was supplied with a constant level of water from external bottle (3 cm, and hydraulic conductivity is determined when the water flow rate in the inner ring is constant. Four areas, two fertilized by mineral fertilizer (areas I and III and two amended with compost (areas II and IV at two depths, 5 and 10 cm (H1-H2, were analysed. The parameters were recorded at the following dates: on 18th and 19th September 2009, respectively, at 5 and 10 cm of depth (H1-H2 in area I; on 7th and 8th October 2009 in area II; on 13th and 14th October 2009 in area III; on 16th and 17th October 2009 in area IV. The effect of compost, used one time only, is present in all parameters, even if with a low statistical significance (P<0.01-0.05. This biomass stores a better water reserve [g (100 g–1-Δθ] and causes a lower avidity for water (bibacity and a better speed of percolation (Ks of exceeding water. The organic matter decreased the variability of soil along field. The studied soil showed to be almost permeable and not having any serious problem concerning rain intensity.

  20. Toxicity of RDX, HMX, TNB, 2,4-DNT, and 2,6-DNT to the Earthworm, Eisenia Fetida, in a Sandy Loam Soil

    National Research Council Canada - National Science Library

    Simini, Michael; Checkai, Ronald T; Kuperman, Roman G; Phillips, Carlton T; Kolakowski, Jan E; Kurnas, Carl W; Sunahara, Geoffrey I

    2006-01-01

    ...), and 1,3,5-trinitrobenzene (TNB) to fill the data gaps. Tests were conducted in freshly amended and in amended soils subjected to a weathering/aging process to better reflect exposure conditions in field soils...

  1. Effects of cropping system and rates of nitrogen in animal slurry and mineral fertilizer on nitrate leaching from a sandy loam

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Hansen, Jørgen Frederik; Kjellerup, Viggo K.

    1993-01-01

    ammonium nitrate (CAN) or animal slurry according to recommended rates (1N) or 50% above recommended rates (1.5N). Compared with unfertilized crops, leaching of nitrate increased only slightly when 1N (CAN) was added. Successive annual additions of 1.5N (CAN) or IN and 1.5N (animal slurry) caused...

  2. Ridge sowing of sunflower (Helianthus annuus L.) in a minimum till system improves the productivity, oil quality, and profitability on a sandy loam soil under an arid climate.

    Science.gov (United States)

    Sher, Ahmad; Suleman, Muhammad; Qayyum, Abdul; Sattar, Abdul; Wasaya, Allah; Ijaz, Muhammad; Nawaz, Ahmad

    2018-04-01

    Sunflower (Helianthus annuus L.) is a major oilseed crop grown for its edible oil across the globe including Pakistan. In Pakistan, the production of edible oil is less than the required quantity; the situation is being worsened with the increasing population. Thus, there is dire need to grow those sunflower genotypes which perform better under a given set of agronomic practices. In this 2-year study, we compared four sunflower genotypes, viz., Armoni, Kundi, Sinji, and S-278 for their yield potential, oil contents, fatty acid composition, and profitability under three sowing methods, viz., bed sowing, line sowing, and ridge sowing and two tillage system, viz., plow till and minimum till. Among the sunflower genotypes, the genotype Armoni produced the highest plant height, number of leaves, head diameter, 1000-achene weight, and achene yield; the oil contents and oleic acid were the highest in genotype Sinji. Among the sowing methods, the highest number of leaves per plant, head diameter, number of achenes per head, achene yield, and oil contents were recorded in ridge sowing. Among the tillage systems, the highest head diameter 16. 2 cm, 1000-achene weight (57.2 g), achene yield (1.8 t ha -1 ), oil contents (35.2%), and oleic acid (15.2%) were recorded in minimum till sunflower. The highest net benefits and benefit to cost ratio were recorded in minimum till ridge sown Armoni genotype. In conclusion, the genotype Armoni should be grown on ridges to achieve the highest achene yield, oil contents, and net profitability.

  3. Toxicity of RDX, HMX, TNB, 2,4-DNT, and 2,6-DNT to the Earthworm, Eisenia Fetida, in a Sandy Loam Soil

    National Research Council Canada - National Science Library

    Simini, Michael; Checkai, Ronald T; Kuperman, Roman G; Phillips, Carlton T; Kolakowski, Jan E; Kurnas, Carl W; Sunahara, Geoffrey I

    2006-01-01

    ...) for ecological risk assessment of soil contaminants at Superfund sites. Insufficient information existed to generate Eco-SSLs for explosives and related materials in soil. The earthworm (Eisenia fetida...

  4. Defying the Definition of Insanity: Assessing the Robust Nature of University Outreach in the Community Using Carnegie Community Engagement Classification and Lynch Outreach Assessment Model (LOAM)

    Science.gov (United States)

    Lynch-Alexander, Erin

    2017-01-01

    Duplicating processes and procedure with anticipation of deviating outcomes is the defining trait of insanity as attributed to a quote by Albert Einstein. It is the antithesis to innovation, which is what is needed in higher education to create impactful changes in the outreach we should be providing to the community. What is important for those…

  5. Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

    Directory of Open Access Journals (Sweden)

    Leila Esmaeelnejad

    2016-06-01

    Full Text Available In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C from two feedstocks (rice husk and apple wood chips. Produced biochars were prepared at two diameters (1-2 mm and <1 mm and mixed with soil at a rate of 2% (w/w. Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks.

  6. Enhancement of physical and hydrological properties of a sandy loam soil via application of different biochar particle sizes during incubation period

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeelnejad, L.; Shorafa, M.; Gorji, M.; Hosseini, S.M.

    2016-11-01

    In spite of many studies that have been carried out, there is a knowledge-gap as to how different sizes of biochars alter soil properties. Therefore, the main objective of this study was to investigate the effects of different sizes of biochars on soil properties. The biochars were produced at two pyrolysis temperatures (350 and 550°C) from two feedstocks (rice husk and apple wood chips). Produced biochars were prepared at two diameters (1-2 mm and <1 mm) and mixed with soil at a rate of 2% (w/w). Multiple effects of type, temperature and size of biochars were significant, so as the mixture of soil and finer woodchip biochars produced at 550°C had significant effects on all soil properties. Soil aggregation and stabilization of macro-aggregates, values of mean weight diameter and water stable aggregates were improved due to increased soil organic matter as binding agents and microbial biomass. In addition, plant available water capacity, air capacity, S-index, meso-pores and water retention content were significantly increased compared to control. But, saturated hydraulic conductivity (Ks) was reduced due to blockage of pores by biochar particles, reduction of pore throat size and available space for flow and also, high field capacity of biochars. So, application of biochar to soil, especially the finest particles of high-tempered woody biochars, can improve physical and hydrological properties of coarse-textured soils and reduce their water drainage by modification of Ks. (Author)

  7. Study of material stability surrounding with loess-clay-loam rocks on an example of 'Olviya' monument of Ukrainian Northern Prichernomor'ya

    International Nuclear Information System (INIS)

    Zlobenko, B.; Kadoshnikov, V.; Manichev, V.; Demchenko, L.; Golovko, T.; Krapivina, V.

    2000-01-01

    In this work we have examined the archaeological material exhumed from the archaeology monument Olviya. The ancient State Olviya is situated on the territory of Ukraine (Nikolaev region) and it is considered to be an integral part of the world historical legacy. The samples of glasses were collected from P-25 excavation. The collected glasses and metals dated by I-II centuries of our era. They are situated in the south-east part of the Upper State on the territory of the Rome times. Study with the facilitation of physical-chemical and physical methods of research of chemical structure and surface layers of materials. The various physical methods of samples investigation were the following: investigation with half-quantitative spectral analysis performed on spectrograph (CTE-1); X-ray powder diffraction with DRON-UM-1 diffractometers use, X-ray fluorescent analysis (spectrometer VPA-30) and the x-ray microanalysis (JXA-5). Carried out microscopic researches have revealed the specific forms of metals and glasses; corrosion and dissolution of the surface that character is determined by structure and physic-chemical conditions of its burial place. (authors)

  8. Growth and yield response of hybrid maize (Zea mays L. to phosphorus levels in sandy loam soil of Chitwan Valley, Nepal

    Directory of Open Access Journals (Sweden)

    Bandhu Raj Baral

    2015-06-01

    Full Text Available To evaluate the phosphorus response on winter hybrid maize, a field experiment was conducted at farm land of National Maize Research Program, Rampur, Chitwan, Nepal on 2012 and 2013. Seven levels of Phosphorus i.e. 0, 20, 40, 60, 80, 100 and 120 kg P2O5 ha-1 were applied along with 160:40 kg N:K2O ha-1. The experiment was laid out in randomized complete block design with three replications. Hybrid maize RML 32 × RML 17 was used for this study. Analysis of variance showed that plant height (cm, dry matter accumulation (g, number of kernels per row, 1000 grain weight (g and grain yield (ton ha-1 were significantly affected with Phosphorus level. The results showed that the trend of increment was positive for grain yield with increased P level from 0 to 80 kg P2O5 ha-1. The highest grain yield (10.77 ton ha-1 was measured when 120 kg P2O5 ha-1 is applied. It is concluded that 80 kg P2O5 ha-1 can be applied in winter season for hybrid maize RML-32 × RML-17 in Chitwan valley low land irrigated condition. Further studies are necessary on different soil types, seasons, management system and varieties to get more information about the most proper addition of P on maize. DOI: http://dx.doi.org/10.3126/ije.v4i2.12634 International Journal of Environment Vol.4(2 2015: 147-156

  9. Common bean growth, N uptake and seed production in sandy loam soil as affected by application of plant residues, nitrogen and irrigation level

    International Nuclear Information System (INIS)

    Abdallah, A.A.G.

    2002-01-01

    Field experiment was conducted at the experimental farm, Inshas, atomic energy authority, egypt. Common bean seeds e.v. Nebrasks were cultivated in sandy loan soil using drip irrigation system prepared for this purpose. Two water regimes, i.e., 100% (793.0 m 3 /fed.) and 65% (513.0 m 3 /fed.) of maximum available water were used in main plots. Where in sub plots two fertilizers types were applied i.e., soybean plant residues which contains N 15 labelled as an organic matter without any addition of any fertilizer and nitrogen as chemical fertilizer without using organic matter. The obtained results indicated that, application of plant residues was superior for total seed yield comparing to nitrogen fertilization treatments. This N source with irrigation level of 793.33 m 3 /fed. had a slight increase in total seed yield comparing with (513.0 m 3 /fed.). Irrigation level of 513.0 m 3 /fed. (65% MAW) as well as application of soybean plant residues showed the highest value of water use efficiency. The highest value of N seed percentage was obtained irrigation level with (513.0 m 3 /fed.). Soybean plant residues improved and increased seeds N content, and total seeds protein content. Both N chemical and irrigation level (65% Maw) recorded highest values with N 15 % atom excess. This result has been obtained at two growth stages and seed yield. The same trend of N 15 % atom excess reflected N utilized with both growth stages and seed yield

  10. Effects of organic versus conventional arable farming on soil structure and organic matter dynamics in a marine loam in the Netherlands

    NARCIS (Netherlands)

    Pulleman, M.M.; Jongmans, A.G.; Marinissen, J.C.Y.; Bouma, J.

    2003-01-01

    We compared the effects of conventional and organic arable farming on soil organic matter (SOM) content, soil structure, aggregate stability and C and N mineralization, which are considered important factors in defining sustainable land management. Within one soil series, three different farming

  11. The influence of clay-to-carbon ratio on soil physical properties in a humid sandy loam soil with contrasting tillage and residue management

    DEFF Research Database (Denmark)

    Getahun, Gizachew Tarekegn; Munkholm, Lars Juhl; Schjønning, Per

    2016-01-01

    × SOC according to Dexter et al. (2008). NCC was a better predictor of dispersible clay than total clay and SOC at all depths in natural aggregates, while tensile strength and derived parameters were generally better explained by the total amount of clay in remoulded aggregates. Remoulded aggregates had...

  12. Field Performance of the Disk Harrow, Power Harrow and Rotary Tiller at Different Soil Moisture Contents on a Clay Loam Soil in Mazandaran

    Directory of Open Access Journals (Sweden)

    M Rajabi Vandechali

    2015-03-01

    Full Text Available About 60% of the mechanical energy consumed in mechanized agriculture is used for tillage operations and seedbed preparation. On the other hand, unsuitable tillage system resulted in soil degradation, affecting soil physical properties and destroying soil structure. The objective of this research was to compare the effects of three types of secondary tillage machines on soil physical properties and their field performances. An experiment was conducted in a wheat farm in Jouybar area of Mazandaran as split plots based on randomized complete block design with three replications. The main independent variable (plot was soil moisture with three levels (23.6-25, 22.2-23.6 and 20.8-22.2 percent based on dry weight and the subplot was three types of machine (two-disk perpendicular passing harrow, Power harrow and Rotary tiller. The measured parameters included: clod mean weight diameter, soil bulk density, specific fuel consumption, machine efficiency and machine capacity. The effects of treatments and their interactions on the specific fuel consumption, machine efficiency and machine capacity and also the effects of treatments on bulk density were significant (P

  13. Effect of Simulated Weathering and Aging of TNT in Amended Sandy Loam Soil on Toxicity to the Enchytraeid Worm, Enchytreaeus Crypticus

    National Research Council Canada - National Science Library

    Kuperman, Roman G; Checkai, Ronald T; Simini, Michael; Phillips, Carlton T; Kolakowski, Jan E; Kurnas, Carl W

    2006-01-01

    ...) for the ecological risk assessment of contaminants at Superfund sites. Insufficient information for TNT to generate Eco-SSL for soil invertebrates has necessitated standardized toxicity testing to fill the data gap...

  14. Effectiveness of the GAEC cross-compliance standard Ploughing in good soil moisture conditions in soil structure protection

    Directory of Open Access Journals (Sweden)

    Maria Teresa Dell'Abate

    2011-08-01

    Full Text Available Researches have been carried out within the framework on the EFFICOND Project, focused at evaluating the effectiveness of the standards of Good Agricultural and Environmental Conditions (GAECs established for Cross Compliance implementation under EC Regulation 1782/2003. In particular the standard 3.1b deals with soil structure protection through appropriate machinery use, with particular reference to ploughing in good soil moisture conditions. The study deals with the evaluation of soil structure after tillage in tilth and no-tilth conditions at soil moisture contents other than the optimum water content for tillage. The Mean Weight Diameter (MWD of water stable aggregates was used as an indicator of tillage effectiveness. The study was carried out in the period 2008-2009 at six experimental farms belonging to Research Centres and Units of the Italian Agricultural Research Council (CRA with different pedo-climatic and cropping conditions. Farm management and data collection in the different sites were carried out by the local CRA researchers and technicians. The comparison of MWD values in tilth and no tilth theses showed statistically significant differences in most cases, depending on topsoil texture. On clay, clay loam, silty clay, and silty clay loam topsoils a general and significant increase of MWD values under no tilth conditions were observed. No significant differences were observed in silt loam and sandy loam textures, probably due to the weak soil structure of the topsoils. Moreover, ploughing in good soil moisture condition determined higher crop production and less weed development than ploughing in high soil moisture conditions.

  15. A History of Pebbles and Silt – Fluvial Sediment Transport, Hydropower and Technical Expertise at the Austrian Danube and its Tributaries

    Directory of Open Access Journals (Sweden)

    Schoder Angelika

    2016-08-01

    Full Text Available The paper investigates experts’ perceptions of hydropower, sediment regime, and their interaction in the 20th century with an environmental historical approach, based on various case studies at both the Danube River and one of its tributaries, and on a review of contemporary literature authored by engineers. Results show that questions of sediment continuity have engaged planners of hydropower plants since the advent of this technology, and decisions were at any time influenced by multiple interests (navigation, electricity demand, nature conservation. In such an intricate fluvial landscape, phenomena like reservoir sedimentation and riverbed incision can be approached as “legacies” of past technical interventions, which limit the options of current and future river management.

  16. Comportamiento dinámico de los sedimentos lacustres de la ciudad de México México city lacustrine silts´ dinamic behavior

    Directory of Open Access Journals (Sweden)

    Jorge Abraham Díaz-Rodríguez

    2010-11-01

    Full Text Available Síntesis de las investigaciones llevadas a cabo por el Grupo de Investigación  Dinámica de Suelos, de la Facultad de Ingeniería de la UNAM, sobre el tema del comportamiento cíclico del subsuelo de la ciudad de México. Se presentan resultados sobre el comportamiento esfuerzo-deformación-tiempo, enparticular el efecto de la carga cíclica sobre el esfuerzo de fluencia, s ’y . En lo concer-niente a la resistencia, se afirma la existencia de una relación umbral de esfuerzos cíclicos,  RD, que define dos patrones de comportamiento. Se enfatiza la importancia de considerar el efecto del tiempo en la medición del módulo de rigidez y el amortiguamiento. Se discuten los dos umbrales de deformación, el umbral lineal, glt, y el umbralde degradación, gdt. Finalmente se presentan resultadosdel efecto de la velocidad de deformación,e&, y la influencia de la estructura del suelo sobre la resistencia no drenada.

  17. Traditional Beach Template vs Cross Shore Swash Zone (CSSZ) Placement Methods at Egmont Key, FL: High Silt Content Beneficial Use Placement

    Science.gov (United States)

    2015-10-15

    Relationships • Swash Zone samples carried 13.2% of the Discharge Slurry fines out of the beach template, thus leaving 5.2% on the beach. *Sampling methods...Tina Underwood , Ms. Erin Duffy USACE Jacksonville District – Mr. Bryan Merrill, Mr. Mike Hensch, Mr. Vic Wilhelm, Mr. Tom Spencer. USACE Engineer

  18. Community Attitude and Associated Factors towards People with Mental Illness among Residents of Worabe Town, Silte Zone, Southern Nation's Nationalities and People's Region, Ethiopia.

    Science.gov (United States)

    Bedaso, Asres; Yeneabat, Tebikew; Yohannis, Zegeye; Bedasso, Kufa; Feyera, Fetuma

    2016-01-01

    Mental illnesses worldwide are accompanied by another pandemic, that of stigma and discrimination. Public understanding about mental illnesses and attitudes towards people with mental illness play a paramount role in the prevention and treatment of mental illness and the rehabilitation of people with mental illness. To assess community attitude and associated factors towards people with mental illness. Community based cross-sectional study was conducted from April 28 to May 28, 2014. Quantitative data were collected through interview from 435 adults selected using simple random sampling. Data were collected using community attitude towards mentally ill (CAMI) tool to assess community attitude towards people with mental illness and associated factors. Multiple linear regression analysis was performed to identify predictors of community attitude towards people with mental illness and the level of significance association was determined by beta with 95% confidence interval and P less than 0.05. The highest mean score was on social restrictiveness subscale (31.55±5.62). Farmers had more socially restrictive view (β = 0.291, CI [0.09, 0.49]) and have less humanistic view towards mentally ill (β = 0.193, CI [-0.36, -0.03]). Having mental health information had significantly less socially restrictive (β = -0.59, CI [-1.13, -0.05]) and less authoritarian (β = -0.10, CI [-1.11, -0.06]) view towards mentally ill but respondents who are at university or college level reported to be more socially restrictive (β = 0.298, CI [0.059, 0.54]). Respondents whose age is above 48 years old had significantly less view of community mental health ideology (β = -0.59, CI [-1.09, -0.08]). Residents of Worabe town were highly socially restrictive but less authoritarian. There was high level of negative attitude towards people with mental illness along all the subscales with relative variation indicating a need to develop strategies to change negative attitude attached to mental illness in Worabe town at community level.

  19. 50 Years And 400 Radiocarbon Measurements Since 1959: What Has The “Bomb Spike” Taught Us About Soil C Dynamics In New Zealand Soils?

    Science.gov (United States)

    Baisden, W. T.; Parfitt, R. L.; Ross, C.

    2009-12-01

    In 1959, Athol Rafter began a substantial programme of monitoring the flow of 14C produced by atmospheric thermonuclear tests through New Zealand’s atmosphere, biosphere and soil. The programme produced important publications, but also leaves a legacy of unpublished data critical for understanding soil C dynamics. A database of ~400 soil radiocarbon measurements spanning 50 years has now been compiled. Among the most compelling data is a comparison of soil carbon dynamics in deforested dairy pastures under similar climate in the Tokomaru silt loam (non-Andisol) versus the Egmont black loam (Andisol), originally sampled in 1962-3, 1965 and 1969. After adding soil profiles sampled to similar depths in 2008, we can use a relatively simple 2-box model to calculate that the residence time of soil C (upper ~8 cm) in the Tokomaru soil is ~9 years compared to ~15 years for the Egmont soil. This difference represents nearly a doubling of soil C residence time, and roughly explains the doubling of the soil C stock. With three measurements in the 1960s, the data is of sufficient resolution to estimate the parameters for an “inert” or “passive pool” comprising approximately 15% of soil C, and having a residence time of 600 years in the Tokomaru soil versus 3000 years in the Egmont surface soil. The Tokomaru/Egmont comparison is necessarily illustrative since the 1960s samplings were not replicated extensively, but provides globally unique data illustrating the nature of C movement through soil. Moreover, the Tokomaru/Egmont comparison supports evidence that C dynamics does differ in Andisols versus other soils. Additional lines of evidence include emerging theories of soil organic matter stabilisation processes, rates of soil organic matter change following land-use change, and chemistry data. The contrasting soil C dynamics in these different soils appear to have implications for land-use change and management schemes that could be eligible for “C credits”. More

  20. Essais de prolifération et d'enracinement de matériel issu de rajeunissement par bouturage d'oliviers adultes (Olea europaea L. et de germination in vitro : effets de cytokinine et d'auxines

    Directory of Open Access Journals (Sweden)

    Walali Loudiyi D

    2005-01-01

    Full Text Available Proliferation and rooting of juvenile and adult olive explants (Olea europaea L.: effects of cytokinin and auxins. The micropropagation trials conducted concerned juvenile and adult material from the ‘Moroccan Picholine’ olive cultivar. Zeatin, added to the proliferation medium, was tested at 0, 1, 5, 10 et 20 mg/l. Root induction was performed on media contaning IAA, IBA or NAA tested at 0, 0.5, 1, 2 et 4 mg/l. A significant (P<0.001 interaction exists between the explant type and the cytokinine concentration on one hand and the type and concentration of auxin on the other hand. The highest bud sprouting and shoot development were obtained on medium supplemented with 5 mg/l zeatin. For economical reasons, satisfying results can be obtained with only 1 mg/l. Rooting of microcuttings reached 100% when NAA, which proved to be the best auxin for root induction, was used at 1 mg/l. No rooting was observed in the case of adult plant material. Further investigations are being undertaken to improve the reactivity of this recalcitrant type of material.

  1. Pour le président estonien, "il faut repenser l'idée mệ̊me de sécurité en Europe" / Olivier Truc

    Index Scriptorium Estoniae

    Truc, Olivier

    2008-01-01

    President Toomas Hendrik Ilves räägib vajadusest muuta Euroopa julgeoleku kontseptsiooni pärast Venemaa agressiooni Gruusias, postmodernse 21. sajandi Euroopa raskustest premodernse 19. sajandi Venemaaga suhtlemisel, Balti riikide kindlustundest Euroopa Liidu ja NATO liikmetena. Eesti riigipea väljendab muret võimaliku Vene-meelse koalitsiooni moodustumise pärast Euroopa Liidus, mis seab rahalised huvid kõrgemale Euroopa põhiväärtustest

  2. On 28 April, CERN welcomed Jean-Claude Petit, director of programmes of the Commissariat á l'Energie Atomique (CEA) in France, and Olivier Pagezy, finance director of the CEA.

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    They visited the assembly hall for the CMS experiment, the COMPASS experiment and the test facilities for the LHC magnets. They are pictured (no 01) in the ATLAS cavern with Peter Jenni, ATLAS spokesman, and Gabriele Fioni, CEA deputy director of programmes

  3. Long-term rotation and tillage effects on soil structure and crop yield

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, R; Deen, B

    2013-01-01

    long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Topsoil measurements were carried out for three different rotations: R1, (C–C–C–C) continuous corn (Zea mays L.), R6, (C–C–O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare L.) and R8, (C......–C–S–S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard ploughing, MP. Topsoil structural quality...

  4. Long-Term Effects of Rotational Tillage On Visual Evaluation of Soil Structure, Soil Quality and Crop Yield

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, Richard; Deen, Bill

    year old long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Measurements were carried out in the topsoil for three different rotations: R1 (C-C-C-C) continuous corn (Zea mays L.), R6. (C-C-O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare...... L.) and R8, (C-C-S-S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard plowing, MP. Topsoil...

  5. Dependence of the phosphate sorption capacity on the aluminium and iron in Finnish soils

    Directory of Open Access Journals (Sweden)

    Armi Kaila

    1963-12-01

    Full Text Available An attempt was made to study to what extent the capacity of the more or less acid soils in Finland to sorb phosphate may be explained on the basis of their content of aluminium and iron. The indicator of the phosphate sorption capacity was calculated on the basis of the Freundlich adsorption isotherm according to the procedure proposed by TERÄSVUORI (8. The material consisted of 390 samples from cultivated and virgin soils representing both topsoils and subsoils. The indicator of the phosphate sorption capacity, the coefficient k, varied in the present material from 40 to 1510. The mean values (with the confidence limits at the 95 per cent level were for the 109 samples of sand and fine sand soils 290 ± 17, for the 103 samples of loam and silt soils 201 ± 24, for the 151 clay soils 308 ± 20, and for the 27 humus soils 236 ± 41. The total linear correlation coefficients between k and the soil pH, and its contents of organic carbon or clay were low or negligible in most of the soil groups. The correlation of k with the content of aluminium extracted by Tamm’s acid ammonium oxalate was fairly close in the clay soils (r = 0.84***, lower in the sand and fine sand soils (r = 0.77***, and in the loam and silt soils, and in the humus soils it was rather poor (r = 0.65*** and 0.63*** resp.. The elimination of the effect of the ammonium oxalate soluble iron decreased the correlation in the two latter groups quite markedly (to 0.32** and 0.37 resp., while the corresponding decrease in the coefficients for the former groups was less significant (to 0.64*** and 0.75*** resp.. The elimination of the effect of the ammonium oxalate soluble aluminium, on the other hand, decreased the correlation coefficients between k and the ammonium oxalate soluble iron in the sand and fine sand soils from 0.59*** to 0.26**, in the loam and silt soils from 0.73*** to 0.54***, in the clay soils from 0.70*** to 0.51***, and in the humus soils from 0.68*** to 0.49*. The

  6. Assessing PAH removal from clayey soil by means of electro-osmosis and electrodialysis

    DEFF Research Database (Denmark)

    Lima, Ana T.; Ottosen, Lisbeth M.; Heister, Katja

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAH) are persistent and toxic contaminants which are difficult to remove from fine porous material like clayey soils. The present work aims at studying two electroremediation techniques for the removal of PAHs from a spiked natural silt soil from Saudi Arabia...... and a silty loam soil from The Netherlands which has been exposed to tar contamination for over 100years. The two techniques at focus are electro-osmosis and electrodialysis. The latter is applied for the first time for the removal of PAH. The efficiency of the techniques is studied using these two soils......, having been subjected to different PAH contact times.Two surfactants were used: the non-ionic surfactant Tween 80 and anionic surfactant sodium dodecyl sulphate (SDS) to aid desorption of PAHs from the soil. Results show a large discrepancy in the removal rates between spiked soil and long-term field...

  7. Wind erosion potential of a winter wheat-summer fallow rotation after land application of biosolids

    Science.gov (United States)

    Pi, Huawei; Sharratt, Brenton; Schillinger, William F.; Bary, Andrew I.; Cogger, Craig G.

    2018-06-01

    Conservation tillage is a viable management strategy to control soil wind erosion, but other strategies such as land application of biosolids that enhance soil quality may also reduce wind erosion. No studies have determined the effects of biosolids on wind erosion. Wind erosion potential of a silt loam was assessed using a portable wind tunnel after applying synthetic and biosolids fertilizer to traditional (disk) and conservation (undercutter) tillage practices during the summer fallow phase of a winter wheat-summer fallow (WW-SF) rotation in 2015 and 2016 in east-central Washington. Soil loss ranged from 12 to 61% lower for undercutter than disk tillage, possibly due to retention of more biomass on the soil surface of the undercutter versus disk tillage treatment. In contrast, soil loss was similar to or lower for biosolids as compared with synthetic fertilizer treatment. Our results suggest that biosolids applications to agricultural lands will have minimal impact on wind erosion.

  8. Effect of integrated N management on the recovery of fertilizer N by rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Hazarika, S.; Sarkar, M.C.

    1996-01-01

    A field experiment was conducted in the kharif season of 1992 on a moderately well drained silt loam (Typic Ustochrept) to study the 15 N recovery from urea applied 60, 120 and 180 kg N/ha to flooded rice (var. Basmati-1) under various N management practices. The results revealed that green manure plus urea registered highest recovery of fertilizer N by rice. The application of coated calcium carbide along with urea reduced the N loss and increased the fertilizer N recovery by rice. Integrated use of manure and urea reduced the N loss to a considerable extent. Green manure was more efficient than farmyard manure in minimizing the loss of fertilizer N. The loss of fertilizer N increased with the increasing rate of urea application. All the sources of N were effective in influencing the N uptake and grain yield of rice but the variations among the sources were not significant. (author). 8 refs., 3 tabs

  9. Evapotranspiration and crop coefficient of oil palm (Elaeis guineensis Jacq.) on the main nursery in a greenhouse

    Science.gov (United States)

    Sigalingging, R.; Sumono; Rahmansyah, N.

    2018-02-01

    The estimation of crop water requirement is an important part of oil palm plantation because fruit yield of oil palm can be affected by water stress. Evapotranspiration and crop coefficient of oil palm using Tenera variety at 7-12 months old was determined. Soil texture was sandy loam with 73.8 % sand, 10.8 % silt, 15.77 % clay and 1.41 % organic matter. The results showed that the oil palm getting older decreased significantly in bulk density, particle density and porosity of soil caused the root of oil palm enlarged (19.42 g to 53.37 g). This was indicated by increased the dry root weight. On the other hand, the value of evapotranspiration and crop coefficient increased significantly, that was 1.85 to 2.00 mm/day and 0.8 to 0.87 respectively.

  10. Release of cadmium from clays and plant uptake of cadium from soil as affected by potassium and calcium amendments

    International Nuclear Information System (INIS)

    Haghiri, F.

    1976-01-01

    The effects of percent K and/or Ca saturations on the release of Cd from Cd-treated H-clays (kaolinite and illite) and on the Cd availability to plants from Cd-treated Canfield silt loam soil were determined. The concentration of Cd in the dialyzates from both kaolinite and illite clays increased as the percent of Ca or K saturation of the clays in the suspension decreased. The release of Cd from both clays was greater in the presence of Ca than K. In a separate experiment, the concentration of Cd in soybean shoots (Glycine max L. Merr.) ''Corsoy'' decreased with increasing percent Ca or K saturation of the soil. The results indicated that Cd uptake by soybeam shoots could be impaired to a great extent by K application

  11. Effect of soil properties on Hydraulic characteristics under subsurface drip irrigation

    Science.gov (United States)

    Fan, Wangtao; Li, Gang

    2018-02-01

    Subsurface drip irrigation (SDI) is a technique that has a high potential in application because of its high efficiency in water-saving. The hydraulic characteristics of SDI sub-unit pipe network can be affected by soil physical properties as the emitters are buried in soils. The related research, however, is not fully explored. The laboratory tests were carried out in the present study to determine the effects of hydraulic factors including operating pressure, initial soil water content, and bulk density on flow rate and its sensitivity to each hydraulic factor for two types of SDI emitters (PLASSIM emitter and Heping emitter). For this purpose, three soils with contrasting textures (i.e., light sand, silt loam, and light clay) were repacked with two soil bulk density (1.25 and1.40 g cm-3) with two initial soil water content (12% and 18%) in plexiglass columns with 40 cm in diameter and 40 cm in height. Drip emitters were buried at depth of 20 cm to measure the flow rates under seven operating pressures (60, 100, 150, 200, 250, 300, and 370 kPa). We found that the operating pressure was the dominating factor of flow rate of the SDI emitter, and flow rate increased with the increase of operating pressure. The initial soil water content and bulk density also affected the flow rate, and their effects were the most notable in the light sand soil. The sensitivity of flow rate to each hydraulic factor was dependent on soil texture, and followed a descending order of light sand>silt loam>light clay for both types of emitters. Further, the sensitivity of flow rate to each hydraulic factor decreased with the increase of operating pressure, initial soil water content, and bulk density. This study may be used to guide the soil specific-design of SDI emitters for optimal water use and management.

  12. Evaluation and optimization of DNA extraction and purification procedures for soil and sediment samples.

    Science.gov (United States)

    Miller, D N; Bryant, J E; Madsen, E L; Ghiorse, W C

    1999-11-01

    We compared and statistically evaluated the effectiveness of nine DNA extraction procedures by using frozen and dried samples of two silt loam soils and a silt loam wetland sediment with different organic matter contents. The effects of different chemical extractants (sodium dodecyl sulfate [SDS], chloroform, phenol, Chelex 100, and guanadinium isothiocyanate), different physical disruption methods (bead mill homogenization and freeze-thaw lysis), and lysozyme digestion were evaluated based on the yield and molecular size of the recovered DNA. Pairwise comparisons of the nine extraction procedures revealed that bead mill homogenization with SDS combined with either chloroform or phenol optimized both the amount of DNA extracted and the molecular size of the DNA (maximum size, 16 to 20 kb). Neither lysozyme digestion before SDS treatment nor guanidine isothiocyanate treatment nor addition of Chelex 100 resin improved the DNA yields. Bead mill homogenization in a lysis mixture containing chloroform, SDS, NaCl, and phosphate-Tris buffer (pH 8) was found to be the best physical lysis technique when DNA yield and cell lysis efficiency were used as criteria. The bead mill homogenization conditions were also optimized for speed and duration with two different homogenizers. Recovery of high-molecular-weight DNA was greatest when we used lower speeds and shorter times (30 to 120 s). We evaluated four different DNA purification methods (silica-based DNA binding, agarose gel electrophoresis, ammonium acetate precipitation, and Sephadex G-200 gel filtration) for DNA recovery and removal of PCR inhibitors from crude extracts. Sephadex G-200 spin column purification was found to be the best method for removing PCR-inhibiting substances while minimizing DNA loss during purification. Our results indicate that for these types of samples, optimum DNA recovery requires brief, low-speed bead mill homogenization in the presence of a phosphate-buffered SDS-chloroform mixture, followed

  13. A study plan for determining recharge rates at the Hanford Site using environmental tracers

    International Nuclear Information System (INIS)

    Murphy, E.M.; Szercsody, J.E.; Phillips, S.J.

    1991-02-01

    This report presents a study plan for estimating recharge at the Hanford Site using environmental tracers. Past operations at the Hanford Site have led to both soil and groundwater contamination, and recharge is one of the primary mechanisms for transporting contaminants through the vadose zone and into the groundwater. An alternative to using fixed lysimeters for determining recharge rates in the vadose zone is to use environmental tracers. Tracers that have been used to study water movement in the vadose zone include total chloride, 36 Cl, 3 H, and 2 H/ 18 O. Atmospheric levels of 36 Cl and 3 H increased during nuclear bomb testing in the Pacific, and the resulting ''bomb pulse'' or peak concentration can be measured in the soil profile. Locally, past operations at the Hanford Site have resulted in the atmospheric release of numerous chemical and isotopic tracers, including nitrate, 129 I, and 99 Tc. Seven study sites on the Hanford Site have been selected, in two primary soil types that are believed to represent the extremes in recharge, the Quincy sand and the Warden silt loam. An additional background study site upwind of the Hanford facilities has been chosen at the Yakima Firing Center. Six tracer techniques (total chloride, 36 Cl, 3 H, nitrate, 129 I, and 99 Tc) will be tested on at least one site in the Quincy sand, one site in the Warden silt loam, and the background site, to determine which combination of tracers works best for a given soil type. In subsequent years, additional sites will be investigated. The use of environmental tracers is perhaps the only cost-effective method for estimating the spatial variability of recharge at a site as large as Hanford. The tracer techniques used at Hanford have wide applicability at other arid sites. 166 refs., 41 figs., 16 tabs

  14. The significance of denitrification of applied nitrogen in fallow and cropped rice soils under different flooding regimes. Pt. 1

    International Nuclear Information System (INIS)

    Fillery, I.R.P.; Vlek, P.L.G.

    1982-01-01

    The role of nitrification-denitrification in the loss of nitrogen from urea applied to puddled soils planted to rice and subjected to continuous and intermittent flooding was evaluated in three greenhouse pot studies. The loss of N via denitrification was estimated indirectly using the 15 N balance, after either first accounting for NH 3 volatilization or by analyzing the 15 N balance immediately before and after the soil was dried and reflooded. When urea was broadcast and incorporated the loss of 15 N from the soil-plant systems depended on the soil, being about 20% - 25% for the silt loams and only 10% - 12% for the clay. Ammonia volatilization accounted for an average 20% of the N applied in the silt loam. Denitrification losses could not account for more than 10% of the applied N in any of the continuously flooded soil-plant systems under study and were most likely less than 5%. Intermittent flooding of soil planted to rice did not increase the loss of N. Denitrification appeared to be an important loss mechanism in continuously flooded fallow soils, accounting for the loss of approximately 40% of the applied 15 N. Loss of 15 N was not appreciably enhanced in fallow soils undergoing intermittent flooding. Apparently, nitrate formed in oxidized zones in the soil was readily denitrified in the absence of plant roots. Extensive loss (66%) of 15 N-labeled nitrate was obtained when 100 mg/pot of nitrate-N was applied to the surface of nonflooded soil prior to reflooding. This result suggests that rice plants may not compete effectively with denitrifiers if large quantities of nitrate were to accumulate during intermittent dry periods. (orig.)

  15. Long-term exposure of /sup 238/PuO/sub 2/ to a terrestrial environment. Volume III

    Energy Technology Data Exchange (ETDEWEB)

    Heaton, R.C.; Patterson, J.H.; Steinkruger, F.J.; Coffelt, K.P.

    1985-02-01

    A plutonium oxide source consisting of a single piece of 83% /sup 238/PuO/sub 2/ and weighing 38 g was exposed for 2.9 years to a humid, temperate terrestrial environment in an environmental simulation chamber. The soil tray of the chamber was divided into four compartments so that different soil types could be studied under identical conditions. Soils examined in this experiment included loam, silt loam, sand, and humus. Plutonium released into the soils, the soil drainages, and the condensates from the dehumidifier was monitored throughout the experiment. The total plutonium release rate from the PuO/sub 2/ source was approximately 2 ng/m/sup 2//s. The generation of short-ranged airborne plutonium, able to travel from a few centimeters to half a meter, was one of the most significant release pathways. The amount of plutonium released in this way was 10 times that washed directly off the source by rainwater and 20 times that from the fully airborne (longer ranged) release. Of the 200 ..mu..g of plutonium deposited in the soils, less than 0.1 ..mu..g was released into the soil percolates. In fact, the soil percolates constituted the least significant release pathway. Within the uncertainties in deriving the plutonium inventories of the soil compartments, we found no discernible differences among the behaviors of the four soil types towards plutonium. There was little or no seasonal effect on the release of plutonium from the soil.

  16. Description of the physical environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds

    International Nuclear Information System (INIS)

    Martin, J.D.; Crawford, C.G.; Duwelius, R.F.; Renn, D.E.

    1990-01-01

    West-central Indiana is underlain by coal-bearing Pennsylvanian rocks. Nearly all of the area has been glaciated at least once and is characterized by wide flood plains and broad, flat uplands. The most productive aquifers are confined or unconfined outwash aquifers located along the major rivers. Bedrock aquifers are regionally insignificant but are the sole source of groundwater for areas that lack outwash, alluvium, or sand and gravel lenses in till. Indiana has > 17 billion short tons of recoverable coal reserves; about 11% can be mined by surface methods. More than 50,000 acres in west-central Indiana were disturbed by surface coal mining from 1941 through 1980. Ridges of mine spoil have been graded to a gently rolling topography. Soils are well drained and consist of 6 to 12 inches of silt-loam topsoil that was stockpiled and then replaced over shale and sandstone fragments of the graded mine spoil. Grasses and legumes form the vegetative cover in each watershed. Pond Creek and the unnamed tributary to Big Branch are streams that drain mined and unreclaimed watersheds. Approximately one-half of the Pond Creek watershed is unmined,agricultural land. Soils are very well drained shaly silty loams that have formed on steeply sloping spoil banks. Both watersheds contain numerous impoundments of water and have enclosed areas that do not contribute surface runoff to streamflow. The ridges of mine spoil are covered with pine trees, but much of the soil surface is devoid of vegetation

  17. Analyzing the Sand-fixing Effect of Feldspathic Sandstone from the Texture Characteristics

    Science.gov (United States)

    Zhang, lu; Ban, Jichang

    2018-01-01

    The purpose of this research was aimed to study the sand fixing effect of feldspathic sandstone in Mu Us Sandy Land, to provide a scienticic basis for desertification control, soil and water conservation and development of farming there. Methods of mixing feldspathic sandstone and aeolian sandy soil according to 1: 0, 1: 1, 1: 2, 1: 5, and 0: 1 mass ratioes, the graded composition and characteristics were studied with laser particle size analyzer. The result showed that these features of sand-based, loosely structured, easy to wind erosion of aeolian sandy soil were changed before feldspathic sandstone and aeolian sandy soil compounding. The <0.05 mm particle mass increased with feldspathic sandstone mass increasing. The texture presented this kind of change from sand to sandy loam to loam to silt loam. The small particle size distribution, good homogeneity and other features of aeolian sandy soil were improved to a certain degree, and the particle size distribution became broad before feldspathic sandstone and aeolian sandy soil compounding. The particle grading was continuous, and the grading characteristic was good when m(F): m(S) was 1: 5(Cu was 54.71 and Cc was 2.54) or when m(F): m(S) was 1: 2(Cu was 76.21, Cc was 1.12). The conclusion is that feldspathic sandstone has sand-fixing effect in texture characteristics, which heightens with feldspathic sandstone mass increasing, and when the mass ratio of feldspathic sandstone: aeolian sandy soil is 1: 2 or 1: 5 which compound better.

  18. Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam.

    Science.gov (United States)

    Nguyen Van, Thinh; Ozaki, Akinori; Nguyen Tho, Hoang; Nguyen Duc, Anh; Tran Thi, Yen; Kurosawa, Kiyoshi

    2016-11-05

    Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As), chromium (Cr), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg -1 . Manganese and iron concentrations averaged 811 µg·g -1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment.

  19. Arsenic and Heavy Metal Contamination in Soils under Different Land Use in an Estuary in Northern Vietnam

    Directory of Open Access Journals (Sweden)

    Thinh Nguyen Van

    2016-11-01

    Full Text Available Heavy metal contamination of soil and sediment in estuaries warrants study because a healthy estuarine environment, including healthy soil, is important in order to achieve ecological balance and good aquaculture production. The Ba Lat estuary of the Red River is the largest estuary in northern Vietnam and is employed in various land uses. However, the heavy metal contamination of its soil has not yet been reported. The following research was conducted to clarify contamination levels, supply sources, and the effect of land use on heavy metal concentrations in the estuary. Soil samples were collected from the top soil layer of the estuary, and their arsenic (As, chromium (Cr, cadmium (Cd, copper (Cu, lead (Pb, and zinc (Zn concentrations were analyzed, as were other soil properties. Most soils in the estuary were loam, silt loam, or sandy loam. The pH was neutral, and the cation exchange capacity ranged from 3.8 to 20 cmol·kg−1. Manganese and iron concentrations averaged 811 µg·g−1 and 1.79%, respectively. The magnitude of the soil heavy metal concentrations decreased in the order of Zn > Pb > Cr > Cu > As > Cd. The concentrations were higher in the riverbed and mangrove forest than in other land-use areas. Except for As, the mean heavy metal concentrations were lower than the permissible levels for agricultural soils in Vietnam. The principal component analyses suggested that soil As, Pb, Zn, Cd, and Cu were of anthropogenic origin, whereas Cr was of non-anthropogenic origin. The spatial distribution of concentration with land use indicated that mangrove forests play an important role in preventing the spread of heavy metals to other land uses and in maintaining the estuarine environment.

  20. Laboratory and field evaluation of broiler litter nitrogen mineralization.

    Science.gov (United States)

    Sistani, K R; Adeli, A; McGowen, S L; Tewolde, H; Brink, G E

    2008-05-01

    Two studies were conducted for this research. First, a laboratory incubation to quantify broiler litter N mineralization with the following treatments: two soil moisture regimes, constant at 60% water fill pore space (WFPS) and fluctuating (60-30% WFPS), three soil types, Brooksville silty clay loam, Ruston sandy loam from Mississippi, and Catlin silt loam from Illinois. Second, a field incubation study to quantify broiler litter N mineralization using similar soils and litter application rates as the laboratory incubation. Broiler litter was applied at an equivalent rate of 350 kg total N ha(-1) for both studies except for control treatments. Subsamples were taken at different timing for both experiments for NO3-N and NH4-N determinations. In the laboratory experiment, soil moisture regimes had no significant impact on litter-derived inorganic N. Total litter-derived inorganic N across all treatments increased from 23 mg kg(-1) at time 0, to 159 mg kg(-1) at 93 d after litter application. Significant differences were observed among the soil types. Net litter-derived inorganic N was greater for Brooksville followed by Ruston and Catlin soils. For both studies and all soils, NH4-N content decreased while NO3-N content increased indicating a rapid nitrification of the mineralized litter N. Litter mineralization in the field study followed the same trend as the laboratory study but resulted in much lower net inorganic N, presumably due to environmental conditions such as precipitation and temperature, which may have resulted in more denitrification and immobilization of mineralized litter N. Litter-derived inorganic N from the field study was greater for Ruston than Brooksville. Due to no impact by soil moisture regimes, additional studies are warranted in order to develop predictive relationships to quantify broiler litter N availability.

  1. Description of the physical environment and coal-mining history of west-central Indiana, with emphasis on six small watersheds

    Science.gov (United States)

    Martin, Jeffrey D.; Crawford, Charles G.; Duwelius, R.F.; Renn, D.E.

    1987-01-01

    Information on the geology, geomorphology, soils, climate, hydrology, water use, land use, population, and coal mining history of Clay, Owen, Sullivan, and Vigo Counties in Indiana is summarized. Site-specific information is given on the morphology , geology, soils, land use, coal mining history, and hydrologic instrumentation of the six watersheds which are each less than 3 sq mi in area. The Wabash, White, and Eel Rivers are the major drainages in west-central Indiana. Average annual precipitation is about 39.5 in/yr and average annual runoff is about 13 in/yr. The most productive aquifers are confined or unconfined outwash aquifers located along the major rivers. Bedrock aquifers are regionally insignificant but are the sole source of groundwater for areas that lack outwash, alluvium, or sand and gravel lenses in till. Indiana has more than 17 billion short tons of recoverable coal reserves; about 11% can be mined by surface methods. Almost half of Indiana 's surface reserves are in Clay, Owen, Sullivan, and Vigo Counties. More than 50,000 acres in west-central Indiana have been disturbed by surface coal mining from 1941 through 1980. Big Slough and Hooker Creek are streams that drain unmined, agricultural watersheds. Row-crop corn and soybeans are the principal crops. Soils are moderately well drained silt loams, and the watersheds well developed dendritic drainage systems. Unnamed tributaries drain mined and reclaimed watersheds. Ridges of mine spoil have been graded to a gently rolling topography. Soils are well drained and consist of 6 to 12 inches of silt-loam topsoil that was stockpiled and then replaced over shale and sandstone fragments of the graded mine spoil. Grasses and legumes form the vegetative cover in each watershed. Pond Creek and an unnamed tributary to Big Branch are streams that drain mined and unreclaimed watersheds. Soils are very well drained shaly silty loams that have formed on steeply sloping banks. Both watersheds contain numerous

  2. The Roman Empire - The Third Century Crisis and Crisis Management

    Science.gov (United States)

    2012-04-04

    December 2010. Hekster, Olivier, Gerda De Kleijn, and Danielle Slootjes. "Introduction." Impact of Empire. 7, (2006, June 1): 3-10. Koselleck...Crisis of the Third Century. Edited by Olivier Hekster, Gerda De Kleijn, and Danielle Slootjes. Vol. 7, Impact of EMpire. Boston: Brill Academic, 2012...1. Protagoras and John Nicols, Mapping the Crisis of the Third Century, ed. Olivier Hekster, Gerda De Kleijn, and Danielle Slootjes

  3. Escoamento superficial e desagregação do solo em entressulcos em solo franco-argilo-arenoso com resíduos vegetais Interrill surface runoff and soil detachment on a sandy clay loam soil with residue cover

    Directory of Open Access Journals (Sweden)

    Elemar Antonino Cassol

    2004-07-01

    Full Text Available A presença de resíduos vegetais sobre a superfície do solo altera as características do escoamento superficial gerado pela chuva e a desagregação e transporte de sedimento resultantes do processo erosivo. O objetivo deste trabalho foi avaliar as condições hidráulicas e as relações de desagregação do solo e de resistência ao escoamento com a presença de resíduos vegetais na erosão em entressulcos. O experimento foi realizado no laboratório, com um Argissolo Vermelho distrófico típico, em parcelas com 0,10 m m-1 de declive sob chuva simulada. O solo foi coberto por resíduos vegetais de palha de soja, nas doses de 0, 0,05, 0,1, 0,2, 0,4 e 0,8 kg m-2. O aumento na cobertura do solo (CS com resíduos vegetais elevou a altura da lâmina de escoamento e a rugosidade hidráulica e reduziu a velocidade média do escoamento, provocada pelo aumento das forças viscosas promovida pela interposição física dos resíduos ao escoamento. O resultado é a redução na taxa de desagregação do solo (Di. A Di foi de 5,35x10-4 kg m-2 s-1 para solo descoberto e 1,50x10-5 kg m-2 s-1 em solo com 100% de cobertura na maior dose de palha. Os modelos de Laflen e potencial foram adequados para estimar o coeficiente de cobertura para resíduo em contato direto com a superfície do solo em função da cobertura do solo.Soil surface cover with crop residue modifies surface flow characteristics, generated by excess rainfall, and soil detachment and sediment transport resulting from the erosion process. The objective of this study was to evaluate the hydraulic conditions, detachment and flow resistance on interrill erosion on soil covered with residue. The experiment was conducted in the laboratory, on a Hapludult soil at a slope of 0.10 m m-1, under simulated rainfall and soil surface covered with soybean residue at the rates of 0, 0.05, 0.1, 0.2, 0.4, and 0.8 kg m-2. The increase in soil surface cover (SC with residue, caused an increase in water flow depth and hydraulic roughness, and a decrease in the mean flow velocity, due to an increase in the viscous forces from the physical interference of residue on runoff, thus contributing to a reduction in interrill soil detachment rate (Di. The Di was 5.35x10-4 kg m-2 s-1 for bare soil and was reduced to 1.50x10-5 kg m-2 s-1 for soil with 100% of surface cover. The Laflen's and the potential models were adequate to estimate the coefficient of soil coverage by residue in direct contact with soil as a function of the soil surface cover.

  4. Comparison of the flows of nitrogen and inorganic phosphorous, dissolved in the Cienaga Grande de Santa Marta, Colombian Caribbean; obtained from incubation cameras in situ and incubation of silt nucleus in laboratory

    International Nuclear Information System (INIS)

    Navas S, Gabriel R; Zea Sven; Campos, Nestor Hernando

    2002-01-01

    This research focused on the comparison of low cost methodologies to determine ionic nitrogen and phosphorous fluxes across the soft sediment-water interface in Cienaga Grande de Santa Marta. In situ transparent incubation chambers and sediment cores for laboratory incubation were employed. It was found that inside the incubation chambers a depletion of dissolved oxygen occurred thus the incubation couldn't be extended for more than six hours, time insufficiently to detect important variations in concentration of the analyzed ions. Furthermore in addition, chambers were difficult to handle. Twenty-four hour sediment core incubation in the laboratory did not have the above-mentioned problems. Oxygen concentration could be kept constant, and ion concentration changes were generally large enough to allow quantitative estimations of the fluxes

  5. Overland Transport of Rotavirus and the Effect of Soil Type and Vegetation

    Directory of Open Access Journals (Sweden)

    Paul C. Davidson

    2016-03-01

    Full Text Available Soil and vegetation are two critical factors for controlling the overland transport kinetics of pathogens in a natural environment. With livestock operations moving more towards concentrated animal operations, the need to dispose of a very large amount of manure in a localized area is becoming increasingly important. Animal manure contains a substantial amount of microbial pathogens, including rotavirus, which may pose a threat of contamination of water resources. This study examined the kinetics of rotavirus in overland transport, with an overall objective of optimizing the design of best management practices, especially vegetative filter strips. The overland transport of rotavirus was studied using three soil types (Catlin silt-loam, Darwin silty-clay, Alvin fine sandy-loam, spanning the entire spectrum of typical Illinois soil textures. A 20-min rainfall event was produced using a small-scale (1.07 m × 0.66 m laboratory rainfall simulator over a soil box measuring 0.610 m × 0.305 m. Each soil type was tested for rotavirus transport kinetics with bare surface conditions, as well as with Smooth Brome and Fescue vegetative covers. Surface runoff, near-surface runoff, soil cores, and vegetation were each analyzed for infective rotavirus particles using cell-culture infectivity assays. Results show that vegetation reduces the recovery of infective rotavirus particles in surface runoff by an average of 73%, in addition to delaying the time to peak recovery. The vegetation, in general, appeared to decrease the recovery of infective rotavirus particles in surface runoff by impeding surface flow and increasing the potential for infiltration into the soil profile.

  6. How does soil management affect carbon losses from soils?

    Science.gov (United States)

    Klik, A.; Trümper, G.

    2009-04-01

    Agricultural soils are a major source as well as a sink of organic carbon (OC). Amount and distribution of OC within the soil and within the landscape are driven by land management but also by erosion and deposition processes. At the other hand the type of soil management influences mineralization and atmospheric carbon dioxide losses by soil respiration. In a long-term field experiment the impacts of soil tillage systems on soil erosion processes were investigated. Following treatments were compared: 1) conventional tillage (CT), 2) conservation tillage with cover crop during the winter period (CS), and 3) no-till with cover crop during winter period (NT). The studies were carried out at three sites in the Eastern part of Austria with annual precipitation amounts from 650 to 900 mm. The soil texture ranged from silt loam to loam. Since 2007 soil CO2 emissions are measured with a portable soil respiration system in intervals of about one week, but also in relation to management events. Concurrent soil temperature and soil water content are measured and soil samples are taken for chemical and microbiological analyses. An overall 14-yr. average soil loss between 1.0 t.ha-1.yr-1 for NT and 6.1 t.ha-1.yr-1 for CT resulted in on-site OC losses from 18 to 79 kg ha-1.yr-1. The measurements of the carbon dioxide emissions from the different treatments indicate a high spatial variation even within one plot. Referred to CT plots calculated carbon losses amounted to 65-94% for NT plots while for the different RT plots they ranged between 84 and 128%. Nevertheless site specific considerations have to be taken into account. Preliminary results show that the adaptation of reduced or no-till management strategies has enormous potential in reducing organic carbon losses from agricultural used soils.

  7. Occurrence of Phytophthora plurivora and other Phytophthora species in oak forests of southern Poland and their association with site conditions and the health status of trees.

    Science.gov (United States)

    Jankowiak, R; Stępniewska, H; Bilański, P; Kolařík, M

    2014-11-01

    Phytophthora plurivora and other Phytophthora species are known to be serious pathogens of forest trees. Little is known, however, about the presence of P. plurivora in Polish oak forests and their role in oak decline. The aims of this study were to identify P. plurivora in healthy and declining Quercus robur stands in southern Poland and to demonstrate the relationship between different site factors and the occurrence of P. plurivora. In addition, the virulence of P. plurivora and other Phytophthora species was evaluated through inoculations using 2-year-old oak seedlings. Rhizosphere soil was investigated from 39 oak stands representing different healthy tree statuses. The morphology and DNA sequences of the internal transcribed spacer regions (ITS) of the ribosomal DNA and the mitochondrial cox1 gene were used for identifications. P. plurivora, an oak fine root pathogen, was isolated from rhizosphere soil samples in 6 out of 39 stands. Additionally, Phytophthora cambivora, Phytophthora polonica and Phytophthora rosacearum-like were also obtained from several stands. The results showed a significant association between the presence of P. plurivora and the health status of oak trees. Similar relationships were also observed for all identified Phytophthora species. In addition, there was evidence for a connection between the presence of all identified Phytophthora species and some site conditions. Phytophthora spp. occurred more frequently in declining stands and in silt loam and sandy loam soils with pH ≥ 3.66. P. plurivora and P. cambivora were the only species capable of killing whole plants, producing extensive necrosis on seedling stems.

  8. Assessment of Cu applications in two contrasting soils-effects on soil microbial activity and the fungal community structure.

    Science.gov (United States)

    Keiblinger, Katharina M; Schneider, Martin; Gorfer, Markus; Paumann, Melanie; Deltedesco, Evi; Berger, Harald; Jöchlinger, Lisa; Mentler, Axel; Zechmeister-Boltenstern, Sophie; Soja, Gerhard; Zehetner, Franz

    2018-03-01

    Copper (Cu)-based fungicides have been used in viticulture to prevent downy mildew since the end of the 19th century, and are still used today to reduce fungal diseases. Consequently, Cu has built up in many vineyard soils, and it is still unclear how this affects soil functioning. The present study aimed to assess the short and medium-term effects of Cu contamination on the soil fungal community. Two contrasting agricultural soils, an acidic sandy loam and an alkaline silt loam, were used for an eco-toxicological greenhouse pot experiment. The soils were spiked with a Cu-based fungicide in seven concentrations (0-5000 mg Cu kg -1 soil) and alfalfa was grown in the pots for 3 months. Sampling was conducted at the beginning and at the end of the study period to test Cu toxicity effects on total microbial biomass, basal respiration and enzyme activities. Fungal abundance was analysed by ergosterol at both samplings, and for the second sampling, fungal community structure was evaluated via ITS amplicon sequences. Soil microbial biomass C as well as microbial respiration rate decreased with increasing Cu concentrations, with EC 50 ranging from 76 to 187 mg EDTA-extractable Cu kg -1 soil. Oxidative enzymes showed a trend of increasing activity at the first sampling, but a decline in peroxidase activity was observed for the second sampling. We found remarkable Cu-induced changes in fungal community abundance (EC 50 ranging from 9.2 to 94 mg EDTA-extractable Cu kg -1 soil) and composition, but not in diversity. A large number of diverse fungi were able to thrive under elevated Cu concentrations, though within the order of Hypocreales several species declined. A remarkable Cu-induced change in the community composition was found, which depended on the soil properties and, hence, on Cu availability.

  9. Parameter importance and uncertainty in predicting runoff pesticide reduction with filter strips.

    Science.gov (United States)

    Muñoz-Carpena, Rafael; Fox, Garey A; Sabbagh, George J

    2010-01-01

    Vegetative filter strips (VFS) are an environmental management tool used to reduce sediment and pesticide transport from surface runoff. Numerical models of VFS such as the Vegetative Filter Strip Modeling System (VFSMOD-W) are capable of predicting runoff, sediment, and pesticide reduction and can be useful tools to understand the effectiveness of VFS and environmental conditions under which they may be ineffective. However, as part of the modeling process, it is critical to identify input factor importance and quantify uncertainty in predicted runoff, sediment, and pesticide reductions. This research used state-of-the-art global sensitivity and uncertainty analysis tools, a screening method (Morris) and a variance-based method (extended Fourier Analysis Sensitivity Test), to evaluate VFSMOD-W under a range of field scenarios. The three VFS studies analyzed were conducted on silty clay loam and silt loam soils under uniform, sheet flow conditions and included atrazine, chlorpyrifos, cyanazine, metolachlor, pendimethalin, and terbuthylazine data. Saturated hydraulic conductivity was the most important input factor for predicting infiltration and runoff, explaining >75% of the total output variance for studies with smaller hydraulic loading rates ( approximately 100-150 mm equivalent depths) and approximately 50% for the higher loading rate ( approximately 280-mm equivalent depth). Important input factors for predicting sedimentation included hydraulic conductivity, average particle size, and the filter's Manning's roughness coefficient. Input factor importance for pesticide trapping was controlled by infiltration and, therefore, hydraulic conductivity. Global uncertainty analyses suggested a wide range of reductions for runoff (95% confidence intervals of 7-93%), sediment (84-100%), and pesticide (43-100%) . Pesticide trapping probability distributions fell between runoff and sediment reduction distributions as a function of the pesticides' sorption. Seemingly

  10. Conditions for the Occurrence of Slaking and Other Disaggregation Processes under Rainfall

    Directory of Open Access Journals (Sweden)

    Frédéric Darboux

    2016-07-01

    Full Text Available Under rainfall conditions, aggregates may suffer breakdown by different mechanisms. Slaking is a very efficient breakdown mechanism. However, its occurrence under rainfall conditions has not been demonstrated. Therefore, the aim of this study was to evaluate the occurrence of slaking under rain. Two soils with silt loam (SL and clay loam (CL textures were analyzed. Two classes of aggregates were utilized: 1–3 mm and 3–5 mm. The aggregates were submitted to stability tests and to high intensity (90 mm·h−1 and low intensity (28 mm·h−1 rainfalls, and different kinetic energy impacts (large and small raindrops using a rainfall simulator. The fragment size distributions were determined both after the stability tests and rainfall simulations, with the calculation of the mean weighted diameter (MWD. After the stability tests the SL presented smaller MWDs for all stability tests when compared to the CL. In both soils the lowest MWD was obtained using the fast wetting test, showing they were sensitive to slaking. For both soils and the two aggregate classes evaluated, the MWDs were recorded from the early beginning of the rainfall event under the four rainfall conditions. The occurrence of slaking in the evaluated soils was not verified under the simulated rainfall conditions studied. The early disaggregation was strongly related to the cumulative kinetic energy, advocating for the occurrence of mechanical breakdown. Because slaking requires a very high wetting rate on initially dry aggregates, it seems unlikely to occur under field conditions, except perhaps for furrow irrigation.

  11. Range expansion potential of two co-occurring invasive vines to marginal habitats in Turkey

    Science.gov (United States)

    Farooq, Shahid; Tad, Sonnur; Onen, Huseyin; Gunal, Hikmet; Caldiran, Ugur; Ozaslan, Cumali

    2017-10-01

    Niche distribution models accurately predict the potential distribution range of invasive plants into new habitats based on their climatic requirements in the native regions. However, these models usually ignore the marginal habitats which can limit the distribution of exotic plants. We therefore tested the seedling survival, growth and nutrient acquisition capabilities of two co-occurring invasive vines [Persicaria perfoliata (L.) H. Gross and Sicyos angulatus L.] in three different manipulative greenhouse experiments to infer their range expansion potential to marginal habitats in Turkey. First experiment included five different moisture availability regimes (100, 75, 50, 25 and 12.5% available water), second experiment consisted of four different salinity levels (0, 3, 6 and 12 dSm-1 soil salinity) and third experiment had four different soil textures (clay-1, clay-2, sandy loam and silt-clay-loam). Seedling mortality was only observed under extreme moisture deficiency in both plant species, while most of the transplanted seedlings of both species did not survive under 6 and 12 dSm-1 salinity levels. Soil textures had no effect on seedling survival. POLPE better tolerated low moisture availability and high salinity compared to SIYAN. Biomass production in both plant species was linearly reduced with increasing salinity and moisture deficiency. SIYAN invested more resources towards shoot, accumulated higher K and P, whereas POLPE maintained higher root-to-shoot ratio under all experimental conditions. Both plant species employed different strategies to cope with adverse environmental conditions, but failed to persist under high soil salinity and moisture deficiency. Our study suggest that both plant species have limited potential of range expansion to marginal habitats and will be limited to moist and humid areas only. Therefore, further research activities should be concentrated in these regions to develop effective management strategies against both species.

  12. Estimate of the soil water retention curve from the sorptivity and β parameter calculated from an upward infiltration experiment

    Science.gov (United States)

    Moret-Fernández, D.; Latorre, B.

    2017-01-01

    The water retention curve (θ(h)), which defines the relationship between the volumetric water content (θ) and the matric potential (h), is of paramount importance to characterize the hydraulic behaviour of soils. Because current methods to estimate θ(h) are, in general, tedious and time consuming, alternative procedures to determine θ(h) are needed. Using an upward infiltration curve, the main objective of this work is to present a method to determine the parameters of the van Genuchten (1980) water retention curve (α and n) from the sorptivity (S) and the β parameter defined in the 1D infiltration equation proposed by Haverkamp et al. (1994). The first specific objective is to present an equation, based on the Haverkamp et al. (1994) analysis, which allows describing an upward infiltration process. Secondary, assuming a known saturated hydraulic conductivity, Ks, calculated on a finite soil column by the Darcy's law, a numerical procedure to calculate S and β by the inverse analysis of an exfiltration curve is presented. Finally, the α and n values are numerically calculated from Ks, S and β. To accomplish the first specific objective, cumulative upward infiltration curves simulated with HYDRUS-1D for sand, loam, silt and clay soils were compared to those calculated with the proposed equation, after applying the corresponding β and S calculated from the theoretical Ks, α and n. The same curves were used to: (i) study the influence of the exfiltration time on S and β estimations, (ii) evaluate the limits of the inverse analysis, and (iii) validate the feasibility of the method to estimate α and n. Next, the θ(h) parameters estimated with the numerical method on experimental soils were compared to those obtained with pressure cells. The results showed that the upward infiltration curve could be correctly described by the modified Haverkamp et al. (1994) equation. While S was only affected by early-time exfiltration data, the β parameter had a

  13. Microbial Response to UV Exposure and Nitrogen Limitation in Desert Soil Crusts

    Science.gov (United States)

    Fulton, J. M.; Van Mooy, B. A.

    2016-12-01

    Microbiotic soil crusts have diverse biomarker distributions and C and N stable isotopic compositions that covary with soil type. Sparse plant cover and the relative lack of soil disturbance in arid/semi-arid landscapes allows populations of soil cyanobacteria to develop along with fungi and heterotrophic bacteria. Microbial communities in this extreme environment depend in part on the production of scytonemin, a UV protective pigment, by cyanobacteria near the top of the crust. N limitation of microbial growth also affects soil crust population dynamics, increasing the requirement of N2fixation by diazotrophic cyanobacteria. We collected 56 soil crust samples from 27 locations throughout the Great Salt Lake Desert, including four transects spanning high-elevation, erosion-dominated soils to lower elevation soils dominated by silt-accumulation. Erosion-dominated soil surfaces included rounded gravel and cobbles; in the interstices there were poorly-developed microbiotic crusts on sandy loam with low δ15N values near 0‰ that point toward microbial growth dependent on cyanobacterial N2 fixation. Nutrients regenerated by heterotrophic bacteria may have been eroded from the system, providing a positive feedback for N2 fixation. High scytonemin:chlorophyll a ratios suggest that cyanobacteria required enhanced protection from UV damage in these crusts. A similar increase in scytonemin:chlorophyll a ratio during soil crust rehydration experiments also points toward the importance of UV protection. Glycolipid:phospholipid ratios were lowest where N2 fixation was favored, however, suggesting that the cyanobacterial population was relatively small, possibly because of the metabolic cost of N2fixation. Microbiotic crusts on silt loam soils, on the other hand, had higher δ15N values between 3.5 and 7.8‰, consistent with heterotrophic growth and nutrient recycling. Lower scytonemin:chlorophyll a ratios suggest that relatively high photosynthetic activity was supported in

  14. Soil Fertility Assessment and Mapping of Regional Agricultural Research Station, Parwanipur, Bara, Nepal

    Directory of Open Access Journals (Sweden)

    Dinesh Khadka

    2018-05-01

    Full Text Available Soil fertility assessment is a key for sustainable planning of a particular area. Thus, the present study was conducted to assess the soil fertility status of the Regional Agricultural Research Station, Parwanipur, Bara, Nepal. The study area is situated at the latitude 27°4’40.9’’N and longitude 84°56’9.85”E at 75masl altitude. Altogether 76 soil samples were collected based on the variability of land at 0-20 cm depth. The texture, pH, OM, total N, available P2O5, K2O, Ca, Mg, S, B, Fe, Zn, Cu and Mn content in the samples were determined following standard analytical methods. Arc-GIS 10.1 was used for soil fertility mapping. The soil structure was angular blocky, and varied between grayish brown (10YR 5/2 and dark grayish brown (10YR 4/2 in color. The sand, silt and clay content were 24.41±0.59%, 54.57±0.44% and 21.03±0.32%, respectively and categorized as silt loam and loam in texture. The soil was moderately acidic in pH (5.67±0.09, low in organic matter (0.74±0.04% and available Sulphur (0.8± 0.1 ppm. The total nitrogen (0.06±0.001%, available boron (0.59±0.08ppm and available zinc (0.51±0.05ppm were low. Furthermore, available potassium (50.26±2.95ppm, available calcium (1674.6±46.3ppm and available magnesium (175.43± 8.93ppm were medium. Moreover, available copper (1.36±0.06 ppm and available manganese (16.52±1.12 ppm were high, while, available phosphorus (77.55±6.65 ppm and available iron (85.88±7.05 ppm were found high. It is expected that the present study would help to guide practices required for sustainable soil fertility management and developing future agricultural research strategy in the farm.

  15. Evaluation of the Removal of Hydrocarbons from Soil Media Using Persulfate Oxidation in the Presence of Mineral Siderite

    Directory of Open Access Journals (Sweden)

    Farzad Mohammadi

    2016-09-01

    Full Text Available Introduction and purpose: Soil contamination by petroleum is mostly resulted from oil exploration, refining processes, leaking of oil products from storage tanks, leaking from pipelines due to pipe friction and decay, refinery wastewater discharge and agricultural irrigation with such materials. Sodium persulfate (Na2S2O8, which is a chemical oxidant, could be activated in the presence of ferrous (Fe2+ and, leading to the treatment of a wide range of soil contaminants. Therefore, this study aimed to evaluate the removal of hydrocarbons from soil media using persulfate oxidation in the presence of mineral siderite. Methods: Initially, oil-contaminated soil was prepared in the form of two separate samples, including silt-clay and sandy-loam soils, which were orderly spiked with 5000 mg fuel oil per kilogram of dry soil. Following that, the effects of various factors, such as different concentrations of persulfate (100-500 mmol/L and siderite (0.1-0.5 g/L, pH (3-9 and temperature (20-60◦C and the removal of petroleum hydrocarbon were assessed.Results: In this study, the optimum condition for degeneration of total petroleum hydrocarbon in silt-clay soils was reported, as follows: temperature: 60◦C, pH: 3, and persulfate/siderite molar ratio of 400 mmol/L to 4.0 g/L. Meanwhile, the optimum condition for the removal of hydrocarbon from sandy-loam soils was pH: 3, temperature: 60◦C and persulfate/siderite molar ratio of 300 mmol/L to 3.0 g/L.Conclusion: According to the results of this study, the optimal amount of persulfate and siderite could be used to remove hydrocarbons from contaminated soils.

  16. Seismic Response to Sonic Boom-Coupled Rayleigh Waves

    Science.gov (United States)

    1990-06-28

    side slopes and moderately deep well-drained, gently sloping to moderately steep soils on terraces; Ann. Rainfall--10" to 16") Cath-Timpahute- Jarab ...slopes less than 15%, and Alluvial land) Jarab Series (cobbley loam, gravelly loam, gravelly clay loam, pan fragments, hardpan with silica laminae...weakly and strongly cemented with lime, soft, calcareous gravelly loam: al!-aline, calcareous) Jarab cobbley loam, 2 to 15% slopes, (JCD) (moderately

  17. Mean Curvature, Threshold Dynamics, and Phase Field Theory on Finite Graphs

    Science.gov (United States)

    2013-06-28

    3380. [DEL12a] Xavier Desquesnes, Abderrahim Elmoataz, and Olivier Lézoray, Eikonal equation adapta- tion on weighted graphs: Fast geometric diffusion...Abderrahim Elmoataz, Olivier Lézoray, and Vinh-Thong Ta, Efficient algorithms for image and high dimensional data processing using eikonal equation on

  18. Description and key to the fifth-instars of some Cicadas (Hemiptera: Cicadidae) associated with coffee plants in Brazil.

    Science.gov (United States)

    Maccagnan, D H B; Martinelli, N M

    2011-01-01

    Fifth-instars of the cicada species Dorisiana drewseni (Stål), Dorisiana viridis (Olivier), Fidicina mannifera (Fabricius), Fidicinoides pronoe (Walker) and Carineta fasciculata (Germar) are described and illustrated. Moreover, a key to the nymphs of these species along with Quesada gigas (Olivier) is also provided.

  19. Soil seal development under simulated rainfall: Structural, physical and hydrological dynamics

    Science.gov (United States)

    Armenise, Elena; Simmons, Robert W.; Ahn, Sujung; Garbout, Amin; Doerr, Stefan H.; Mooney, Sacha J.; Sturrock, Craig J.; Ritz, Karl

    2018-01-01

    This study delivers new insights into rainfall-induced seal formation through a novel approach in the use of X-ray Computed Tomography (CT). Up to now seal and crust thickness have been directly quantified mainly through visual examination of sealed/crusted surfaces, and there has been no quantitative method to estimate this important property. X-ray CT images were quantitatively analysed to derive formal measures of seal and crust thickness. A factorial experiment was established in the laboratory using open-topped microcosms packed with soil. The factors investigated were soil type (three soils: silty clay loam - ZCL, sandy silt loam - SZL, sandy loam - SL) and rainfall duration (2-14 min). Surface seal formation was induced by applying artificial rainfall events, characterised by variable duration, but constant kinetic energy, intensity, and raindrop size distribution. Soil porosities derived from CT scans were used to quantify the thickness of the rainfall-induced surface seals and reveal temporal seal micro-morphological variations with increasing rainfall duration. In addition, the water repellency and infiltration dynamics of the developing seals were investigated by measuring water drop penetration time (WDPT) and unsaturated hydraulic conductivity (Kun). The range of seal thicknesses detected varied from 0.6 to 5.4 mm. Soil textural characteristics and OM content played a central role in the development of rainfall-induced seals, with coarser soil particles and lower OM content resulting in thicker seals. Two different trends in soil porosity vs. depth were identified: i) for SL soil porosity was lowest at the immediate soil surface, it then increased constantly with depth till the median porosity of undisturbed soil was equalled; ii) for ZCL and SL the highest reduction in porosity, as compared to the median porosity of undisturbed soil, was observed in a well-defined zone of maximum porosity reduction c. 0.24-0.48 mm below the soil surface. This

  20. Estimating Penetration Resistance in Agricultural Soils of Ardabil Plain Using Artificial Neural Network and Regression Methods

    Directory of Open Access Journals (Sweden)

    Gholam Reza Sheykhzadeh

    2017-02-01

    replicates. The data were divided into two series as 78 data for training and 27 data for testing. The SPSS 18 with stepwise method and MATLAB software were used to derive the regression and artificial neural network, respectively. A feed forward three-layer (8, 11 and 15 neurons in the hidden layer perceptron network and the tangent sigmoid transfer function were used for the artificial neural network modeling. In estimating penetration resistance, The accuracy of artificial neural network and regression pedotransfer functions were evaluated by coefficient of determination (R2, root mean square error (RMSE, mean error (ME and Akaike information criterion (AIC statistics. Results and discussion: The textural classes of study soils were loamy sand (n= 8, sandy loam (n= 70, loam (n= 6 and silt loam (n= 21. The values of sand (26.26 to 87.43 %, clay (3.99 to 17.34 %, organic carbon (0.3 to 2.41 %, field moisture (4.56 to 33.18 mass percent, Db (1.02 to 1.63 g cm-3 and penetration resistance (1.1 to 6.6 MPa showed a large variations of study soils. There were found significant correlations between penetration resistance and sand (r= - 0.505**, silt (r= 0.447**, clay (r= 0.330**, organic carbon (r= - 0.465**, Db (r= 0.655**, θf (r= -0.63**, CaCO3 (r= 0.290**, total porosity (r= - 0.589** and Dp (r= 0.266*. Generally, 15 regression and artificial neural network pedotransfer functions were constructed to predict penetration resistance from measured readily available soil variables. The results of regression and artificial neural network pedotransfer functions showed that the most suitable variables to estimate penetration resistance were θf, Db and particles size distribution. The input variables were n and θf for the best regression pedotransfer function and also Db, silt, θf and σg for the best artificial neural network pedotransfer function. The values of R2, RMSE, ME and AIC were obtained equal to 0.55, 0.89 MPa, 0.05 MPa and -14.67 and 0.91, 0.37 MPa, - 0.0026 MPa and

  1. Soils of the Eastern mountainsides of the southern Sikhote-Alin (on the example of Lazovsky nature reserve, Russia)

    Science.gov (United States)

    Tregubova, Valentina; Semal, Victoria; Nesterova, Olga; Yaroslavtsev, Alexis

    2017-04-01

    The most common soils of the southern Far East are Brownzems under Russian classification (Cambisols), which are the zonal ones, emerging on the steep slopes and tops of hills, on high river terraces under broad-leaved and cedar-broad-leaved forests. Those soils formed due to two processes: organic matter metamorphism and clayization by siallite, leading to the formation of clay-metamorphic horizon Bw. The main morphological features of Cambisols are not deep soil profile (50 - 70 cm), weak horizons differentiation, with lots of cobble. Chemically those soils are low saturated, even in the humus horizon. Distribution of total absorbed bases is mostly accumulative, which is related to the distribution of humus in these soils, and the predominant type of clay fraction distribution of. The only exception are Humic Cambisols and Humic Cambisols Calcic which were formed on redeposited products of limestone rock weathering. Fine-grained deposits are mainly loams with a low content of silt. Silt distribution has an accumulative character with a gradual decrease in the content of silt down from the top of the profile. Layer of fresh leaf fall is very common for the Humic Cambisols surfaces, and under it there is the litter of plant residues with different degrees of decomposition. Accumulative humus horizon is dark gray with brownish tint, thin, from 10 to 15 cm in depth, loose, crumbly, highly penetrated by roots, with a strong granular structure, with aggregates tightly attached to the root hairs, sandy loam or sandy clay loam. The middle horizon is brown, yellowish-brown, divided into sub-horizons, with different color intensity, density, soil texture and amount of cobble. Dystric Cambisols are acidic or strongly acidic with low saturation of soil absorbing complex. Due to amount and distribution of organic matter these soils can be divided into two groups. The first group is soils with accumulative humus distribution: with a low depth humus-accumulative horizon (11

  2. Infiltration performance of engineered surfaces commonly used for distributed stormwater management.

    Science.gov (United States)

    Valinski, N A; Chandler, D G

    2015-09-01

    Engineered porous media are commonly used in low impact development (LID) structures to mitigate excess stormwater in urban environments. Differences in infiltrability of these LID systems arise from the wide variety of materials used to create porous surfaces and subsequent maintenance, debris loading, and physical damage. In this study, the infiltration capacity of six common materials was tested by multiple replicate experiments with automated mini-disk infiltrometers. The tested materials included porous asphalt, porous concrete, porous brick pavers, flexible porous pavement, engineered soils, and native soils. Porous asphalt, large porous brick pavers, and curb cutout rain gardens showed the greatest infiltration rates. Most engineered porous pavements and soils performed better than the native silt loam soils. Infiltration performance was found to be related more to site design and environmental factors than material choice. Sediment trap zones in both pavements and engineered soil rain gardens were found to be beneficial to the whole site performance. Winter chloride application had a large negative impact on poured in place concrete, making it a poor choice for heavily salted areas. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Soil of the lower valley of the Dragonja river (Slovenia

    Directory of Open Access Journals (Sweden)

    Tomaž PRUS

    2015-11-01

    Full Text Available Soil of the lower valley of the river Dragonja developed under specific soil-forming factors. Soil development in the area was influenced by alluvial sediments originating from surrounding hills, mostly of flysch sequence rocks, as a parent material, Sub-Mediterranean climate and the vicinity of the sea. Different soil classification units (Gleysol and Fluvisol were proposed for that soil in previous researches. The aim of our study was the evaluation of morphological, chemical and mineralogical characteristics of soil, based on detailed soil description and analyses, and to define the appropriate soil classification units. Field examinations revealed that the soil had a stable blocky or subangular structure and did not express substantial hydromorphic forms. Soil pH value was ranging from 6.9 to 7.5. In most locations electroconductivity (ECe did not exceed 2 ds/m. Base saturation was high (up to 99 %, with a majority of Ca2+ ions. Exchangeable sodium percentage (ESP was ranging from 0.2 to 3.8 %, which is higher compared to other Slovenian soils but does not pose a risk to soil structure. Soil has silty clay loam texture with up to 66 % of silt. Prevailing minerals were quartz, calcite and muscovite/illite. No presence of swelling clay mineral montmorillonite was detected. According to Slovenian soil classification, we classified the examined soil as alluvial soil. According to WRB soil classification, the soil was classified as Cambisol.

  4. Wind erosion potential after land application of biosolids

    Science.gov (United States)

    PI, H.; Sharratt, B. S.; Schillinger, W. F.; Bary, A.; Cogger, C.

    2017-12-01

    The world population is currently 7.6 billion and, along with continued population growth, comes the challenge of disposing of wastewater and sewage sludge (biosolids). Applying biosolids to agricultural land to replace synthetic fertilizers represents a relatively safe method to recycle or sustainably use biosolids. While land application of biosolids is recognized as a sustainable management practice for enhancing soil health, no studies have determined the effects of biosolids on soil wind erosion. Wind erosion potential of a silt loam was assessed using a portable wind tunnel after applying synthetic and biosolid fertilizer to conventional and conservation tillage practices during the summer fallow phase of a winter wheat-summer fallow rotation in 2015 and 2016 in east-central Washington. Little difference in soil loss was observed between biosolid and synthetic fertilizer treatments, but this result appeared to be dependent on susceptibility of the soil to erosion. Regression analysis between soil loss from fertilizer or tillage treatments indicated that soil loss was lower from biosolid versus synthetic fertilizer and conservation versus conventional tillage at high erosion rates. This suggests that biosolids may reduce wind erosion under highly erodible conditions. Meanwhile, heavy metal concentrations in the windblown sediment were similar for the biosolid and synthetic fertilizer treatments whereas metal loss in windblown sediment was 10% lower from biosolid than synthetic fertilizer. Our results indicate that land application of biosolids did not accelerate the loss of metals or nutrients from soils during high winds. KeywordsLand application of biosolids; wind erosion; wind tunnel; sustainable agriculture

  5. Variations in water balance and recharge potential at three western desert sites

    International Nuclear Information System (INIS)

    Gee, G.W.; Fayer, M.J.; Rockhold, M.L.; Wierenga, P.J.; Young, M.H.; Andraski, B.J.

    1994-01-01

    Radioactive and hazardous waste landfills exist at numerous desert locations in the USA. At these locations, annual precipitation is low and soils are generally dry, yet little is known about recharge of water and transport of contaminants to the water table. Recent water balance measurements made at three desert locations, Las Cruces, NM, Beatty, NV, and the U.S. Department of Energy's Hanford Site in the state of Washington, provide information on recharge potential under three distinctly different climate and soil conditions. All three sites show water storage increases with time when soils are coarse textured and plants are removed from the surface, the rate of increase being influenced by climatic variables such as precipitation, radiation, temperature, and wind. Lysimeter data from Hanford and Las Cruces indicate that deep drainage (recharge) from bare, sandy soils can range from 10 to > 50% of the annual precipitation. At Hanford, when desert plants are present on sandy or gravelly surface soils, deep drainage is reduced but not eliminated. When surface soils are silt loams, deep drainage is eliminated whether plants are present or not. At Las Cruces and Beatty, the presence of plants eliminated deep drainage at the measurement sites. Differences in water balance between sites are attributed to precipitation quantity and distribution and to soil and vegetation types. The implication of waste management at desert locations is that surface soil properties and plant characteristics must be considered in waste site design in order to minimize recharge potential. 39 refs., 9 figs., 3 tabs

  6. Nitrogen Utilization and Environmental Losses from Organic Farming and Biochar's Potential to Improve N Efficiency.

    Science.gov (United States)

    Pereira, E. I.; SIX, J. W. U. A.

    2014-12-01

    The response of plant performance and nitrogen (N) dynamics to biochar amendments were studied across various levels of N input for two growing seasons in mesocosms representing an organic lettuce production systems. A silt loam soil was amended with pine chip (PC) and walnut shell (WS) biochar (10 t ha-1) in combination with five organic N fertilization rates 0%, 25%, 50%, 75%, and 100% of 225 kg N ha-1. N output through harvest, leachate, and nitrous oxide (N2O) emissions were determined to assess N utilization and environmental losses of biochar-amended soils. Analysis of plant performance indicate that PC and WS biochar did not provide any increases in plant biomass in soils that received less than business-as-usual fertilization rates. At 100% N fertilization rate, biochar amendments (both PC and WS) improved lettuce biomass production, which resulted in significant increases in NUE with no effects on N2O emissions. Furthermore, N losses via leaching were decreased by PC biochar at 100% N fertilization rates. Thus, due to increases in plant biomass and decreases in N losses via leachate, PC biochar significantly decreased the ratio of N lost over N exported in biomass. Findings from this study suggest that biochar can provide some beneficial effects to organic farming systems, however, not in all circumstances, given the effects seem to vary with biochar type and fertilization level.

  7. Model assessment of protective barrier designs

    International Nuclear Information System (INIS)

    Fayer, M.J.; Conbere, W.; Heller, P.R.; Gee, G.W.

    1985-11-01

    A protective barrier is being considered for use at the Hanford site to enhance the isolation of previously disposed radioactive wastes from infiltrating water, and plant and animal intrusion. This study is part of a research and development effort to design barriers and evaluate their performance in preventing drainage. A fine-textured soil (the Composite) was located on the Hanford site in sufficient quantity for use as the top layer of the protective barrier. A number of simulations were performed by Pacific Northwest Laboratory to analyze different designs of the barrier using the Composite soil as well as the finer-textured Ritzville silt loam and a slightly coarser soil (Coarse). Design variations included two rainfall rates (16.0 and 30.1 cm/y), the presence of plants, gravel mixed into the surface of the topsoil, an impermeable boundary under the topsoil, and moving the waste form from 10 to 20 m from the barrier edge. The final decision to use barriers for enhanced isolation of previously disposed wastes will be subject to decisions resulting from the completion of the Hanford Defense Waste Environmental Impact Statement, which addresses disposal of Hanford defense high-level and transuranic wastes. The one-dimensional simulation results indicate that each of the three soils, when used as the top layer of the protective barrier, can prevent drainage provided plants are present. Gravel amendments to the upper 30 cm of soil (without plants) reduced evaporation and allowed more water to drain

  8. Soil and Crop management: Lessons from the laboratory biosphere 2002-2004

    Science.gov (United States)

    Silverstone, S.; Nelson, M.; Alling, A.; Allen, J.

    During the years 2002 and 2003, three closed system experiments were carried out in the "Laboratory Biosphere" facility located in Santa Fe, New Mexico. The program involved experimentation with "Hoyt" Soy Beans, USU Apogee Wheat and TU-82-155 sweet potato using a 5.37 m2 soil planting bed which was 30 cm deep. The soil texture, 40% clay, 31% sand and 28% silt (a clay loam), was collected from an organic farm in New Mexico to avoid chemical residues. Soil management practices involved minimal tillage, mulching and returning crop residues to the soil after each experiment. Between experiment #2 and #3, the top 15 cm of the soil was amended using a mix of peat moss, green sand, humates and pumice to improve soil texture, lower soil pH and increase nutrient availability. Soil analyses for all three experiments are presented to show how the soils have changed with time and how the changes relate to crop selection and rotation, soil selection and management, water management and pest control. The experience and information gained from these experiments are being applied to the future design of the Mars On Earth facility.

  9. Survival of a Rifampicin-Resistant Pseudomonas fluorescens Strain in Nine Mollisols

    Directory of Open Access Journals (Sweden)

    Tami L. Stubbs

    2014-01-01

    Full Text Available Pseudomonas fluorescens strain D7 (P.f. D7 is a naturally occurring soil bacterium that shows promise as a biological herbicide to inhibit growth of annual grass weeds, including downy brome (Bromus tectorum L., in crop- and rangelands. Pseudomonas fluorescens strain D7rif (P.f. D7rif is a rifampicin-resistant strain of P.f. D7. One of the greatest obstacles to successful biological weed control is survival of the organism under field conditions. Nine soils in the taxonomic order of Mollisols, collected from downy brome-infested areas of the Western and Central United States, were inoculated with P.f. D7rif and incubated in the laboratory to determine the effects of soil type, soil properties, incubation temperature, and soil water potential on survival of P.f. D7rif over 63 days. Silt loam soils from Lind, Washington, and Moro, Oregon, sustained the highest P.f. D7rif populations, and recovery was the lowest from Pendleton, Oregon soil. Survival and recovery of P.f. D7rif varied with soil type and temperature but not with the two soil water potentials tested. After 63 days, P.f. D7rif was recovered at levels greater than log 5.5 colony forming units (CFU g−1 soil from five of the nine test soils, a level adequate to suppress downy brome under field or range conditions.

  10. Effect of organic fertilizers derived dissolved organic matter on pesticide sorption and leaching

    Energy Technology Data Exchange (ETDEWEB)

    Li Kun [Department of Plant, Soil, and Insect Sciences, Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States); Xing Baoshan [Department of Plant, Soil, and Insect Sciences, Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States) and Northeast Institute of Geography and Agro-ecology, CAS, Harbin 150040 (China)]. E-mail: bx@pssci.umass.edu; Torello, William A. [Department of Plant, Soil, and Insect Sciences, Stockbridge Hall, University of Massachusetts, Amherst, MA 01003 (United States)

    2005-03-01

    Incorporation of organic fertilizers/amendments has been, and continues to be, a popular strategy for golf course turfgrass management. Dissolved organic matter (DOM) derived from these organic materials may, however, facilitate organic chemical movement through soils. A batch equilibrium technique was used to evaluate the effects of organic fertilizer-derived DOM on sorption of three organic chemicals (2,4-D, naphthalene and chlorpyrifos) in USGA (United States Golf Association) sand, a mixed soil (70% USGA sand and 30% native soil) and a silt loam soil (Typic Fragiochrept). DOM was extracted from two commercial organic fertilizers. Column leaching experiments were also performed using USGA sand. Sorption experiments showed that sorption capacity was significantly reduced with increasing DOM concentration in solution for all three chemicals. Column experimental results were consistent with batch equilibrium data. These results suggest that organic fertilizer-derived DOM might lead to enhanced transport of applied chemicals in turf soils. - Dissolved organic matter could result in enhanced transport of chemicals applied to turf.

  11. SSEM: A model for simulating runoff and erosion of saline-sodic soil slopes under coastal reclamation

    Science.gov (United States)

    Liu, Dongdong; She, Dongli

    2018-06-01

    Current physically based erosion models do not carefully consider the dynamic variations of soil properties during rainfall and are unable to simulate saline-sodic soil slope erosion processes. The aim of this work was to build upon a complete model framework, SSEM, to simulate runoff and erosion processes for saline-sodic soils by coupling dynamic saturated hydraulic conductivity Ks and soil erodibility Kτ. Sixty rainfall simulation rainfall experiments (2 soil textures × 5 sodicity levels × 2 slope gradients × 3 duplicates) provided data for model calibration and validation. SSEM worked very well for simulating the runoff and erosion processes of saline-sodic silty clay. The runoff and erosion processes of saline-sodic silt loam were more complex than those of non-saline soils or soils with higher clay contents; thus, SSEM did not perform very well for some validation events. We further examined the model performances of four concepts: Dynamic Ks and Kτ (Case 1, SSEM), Dynamic Ks and Constant Kτ (Case 2), Constant Ks and Dynamic Kτ (Case 3) and Constant Ks and Constant Kτ (Case 4). The results demonstrated that the model, which considers dynamic variations in soil saturated hydraulic conductivity and soil erodibility, can provide more reasonable runoff and erosion prediction results for saline-sodic soils.

  12. Physical and water properties of selected Polish heavy soils of various origins

    Directory of Open Access Journals (Sweden)

    Kaczmarek Zbigniew

    2015-12-01

    Full Text Available The paper presents the characteristics of selected physical, chemical, and water properties of four mineral arable soils characterized with heavy and very heavy texture. Soil samples from genetic horizons of black earths from areas near Kętrzyn, Gniew and Kujawy, and alluvial soils from Żuławy were used. The following properties were determined in the samples of undisturbed and disturbed structure: texture, particle density, bulk density, porosity, natural and hygroscopic moistures, maximal hygroscopic capacity, saturated hydraulic conductivity, potential of water bonding in soil, total and readily available water, total retention in the horizon of 0–50 cm, drainage porosity, content of organic carbon and total nitrogen Parent rocks of these soils were clays, silts and loams of various origin. High content of clay fraction strongly influenced the values of all the analyzed properties. All the examined soils had high content of organic carbon and total nitrogen and reaction close to neutral or alkaline. High content of mineral and organic colloids and, what follows, beneficial state of top horizons’ structure, determined – apart from heavy texture – low soil bulk density and high porosity. The investigated soils were characterized by high field water capacity and wide scopes of total and readily available water. The saturated hydraulic conductivity was low and characteristic to heavy mineral arable soils. The parameter which influenced the variability of analyzed parameters most was texture.

  13. Reducing the leachability of nitrate, phosphorus and heavy metals from soil using waste material

    Directory of Open Access Journals (Sweden)

    Faridullah

    Full Text Available Abstract Contaminants like nitrate (NO3, phosphorus (P and heavy metals in water are often associated with agricultural activities. Various soil and water remediation techniques have been employed to reduce the risk associated with these contaminants. A study was conducted to examine the extent of leaching of heavy metals (Cd, Ni, Pb and Cr, NO3 and P. For this purpose sandy and silt loam soils were amended with different waste materials, namely wood ash, solid waste ash, vegetable waste, charcoal, and sawdust. The soils were saturated with wastewater. Irrespective of the waste applied, the pH and EC of the amended soils were found to be greater than the control. Charcoal, sawdust and wood ash significantly decreased heavy metals, nitrate and phosphorus concentrations in the leachate. Treatments were more efficient for reducing Ni than other heavy metals concentrations. Waste amendments differed for heavy metals during the process of leaching. Heavy metals in the soil were progressively depleted due to the successive leaching stages. This research suggests that waste material may act as an adsorbent for the above contaminants and can reduce their leachability in soils.

  14. Biointrusion test plan for the Permanent Isolation Surface Barrier Prototype

    International Nuclear Information System (INIS)

    Link, S.O.; Cadwell, L.L.; Brandt, C.A.; Downs, J.L.; Rossi, R.E.; Gee, G.W.

    1994-04-01

    This document provides a testing and monitoring plan for the biological component of the prototype barrier slated for construction at the Hanford Site. The prototype barrier is an aboveground structure engineered to demonstrate the basic features of an earthen cover system. It is designed to permanently isolate waste from the biosphere. The features of the barrier include multiple layers of soil and rock materials and a low-permeability asphalt sublayer. The surface of the barrier consists of silt loam soil, covered with plants. The barrier sides are reinforced with rock or coarse earthen-fill to protect against wind and water erosion. The sublayers inhibit plant and animal intrusion and percolation of water. A series of tests will be conducted on the prototype barrier over the next several years to evaluate barrier performance under extreme climatic conditions. Plants and animals will play a significant role in the hydrologic and water and wind erosion characteristics of the prototype barrier. Studies on the biological component of the prototype barrier will include work on the initial revegetation of the surface, continued monitoring of the developing plant community, rooting depth and dispersion in the context of biointrusion potential, the role of plants in the hydrology of the surface and toe regions of the barrier, the role of plants in stabilizing the surface against water and wind erosion, and the role of burrowing animals in the hydrology and water and wind erosion of the barrier

  15. Numerical simulation studies of the groundwater discharge to streams from abandoned uranium mill tailings

    International Nuclear Information System (INIS)

    Abdul, A.S.; Gillham, R.W.

    1984-06-01

    This report presents an evaluation of the results of simulation studies of groundwater discharge to streams from abandoned uranium mill tailings and the effects of this discharge on the flux of contaminants to surface water systems. In particular, a discussion of the sensitivity of subsurface discharge to specific geometirc, climatic and hydrogeologic factors is presented. Simulations were carried out using a two-dimensional numerical finite-element unsaturated-saturated flow model. A total of twenty-six simulations were made. The first twenty-four of these considered a tailings medium with homogeneous and isotropic hydraulic properties and with textural properties similar to those of sandy geological materials. In addition, two simulations were carried out for tailings materials with hydraulic properties that are similar to those of silt-loam. The results indicated that the actual quantity of subsurface discharge depends on many factors including rainfall rate and duration, surface slope, and texture. However, for the medium-fine sand material, subsurface discharge was always a significant component of the total discharge. Within the context of uranium tailings management this implies that large quantities of contaminants from subsurface sources of medium-textured tailings can be expected to be discharged to streams during stormflow events. Therefore there is reason to suspect that untreated runoff from such tailings will contain significant concentrations of contaminants for long periods of time

  16. Imaging and locating paleo-channels using geophysical data from meandering system of the Mun River, Khorat Plateau, Northeastern Thailand

    Science.gov (United States)

    Nimnate, P.; Thitimakorn, T.; Choowong, M.; Hisada, K.

    2017-12-01

    The Khorat Plateau from northeast Thailand, the upstream part of the Mun River flows through clastic sedimentary rocks. A massive amount of sand was transported. We aimed to understand the evolution of fluvial system and to discuss the advantages of two shallow geophysical methods for describing subsurface morphology of modern and paleo-channels. We applied Electrical Resistivity Tomography (ERT) and Ground Penetrating Radar (GPR) to characterize the lateral, vertical morphological and sedimentary structures of paleo-channels, floodplain and recent point bars. Both methods were interpreted together with on-sites boreholes to describe the physical properties of subsurface sediments. As a result, we concluded that four radar reflection patterns including reflection free, shingled, inclined and hummocky reflections were appropriated to apply as criteria to characterize lateral accretion, the meandering rivers with channel-filled sequence and floodplain were detected from ERT profiles. The changes in resistivity correspond well with differences in particle size and show relationship with ERT lithological classes. Clay, silt, sand, loam and bedrock were classified by the resistivity data. Geometry of paleo-channel embayment and lithological differences can be detected by ERT, whereas GPR provides detail subsurface facies for describing point bar sand deposit better than ERT.

  17. Extractable trace elements and sodium in Illinois coal-cleaning wastes: correlation with concentrations in tall fescue

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, B.G.

    1983-07-01

    Trace element concentrations in shoots of tall fescue (Festuca arundinacea Schreb.) were correlated with extractable element concentrations in five southern Illinois coal-cleaning wastes limed to pH 6.5, in a greenhouse study to determine applicability of soil tests to coal-waste evaluation. There was little or no correlation between shoot concentrations of Fe, and Fe extracted from the wastes by dilute acid (r equals 0.60), DTPA at pH 6.4 (r equals 0.47) or DTPA at pH 8.4 (r equals -0.17). The corresponding r values for Mn were 0.94, 0.97, and 0.96; for Zn, 0.96, 0.96, and 0.88; and for Cu, 0.67, 0.90, and 0.88, respectively. Shoot B correlated well with hot water-soluble B(r equals 0.96) and acid-soluble B(r equals 0.91). Correlations for shoot Na were also good with water-soluble Na and acid-soluble Na (r equals 0.96 in both cases). Concentrations of Al, As, Cd, Ni, Pb, and Se in the shoots were well below reported upper critical levels, and similar to concentrations in the grass grown on a silt loam under the same greenhouse conditions. 21 references.

  18. Efficacy of Natural Polymer Derivatives on Soil Physical Properties and Erosion on an Experimental Loess Hillslope.

    Science.gov (United States)

    Liu, Jun'e; Wang, Zhanli; Li, Yuanyuan

    2017-12-22

    Raindrops disperse large soil aggregates into smaller particles, which can clog soil pores, cause soil crusting, reduce rainfall infiltration and increase soil loss. It was found that natural polymer derivatives were effective in improving soil physical properties and decreasing soil erosion on an experimental loess hillslope. This study investigated the effect of new natural polymer derivatives (Jag S and Jag C162) on soil properties, rainfall infiltration and sediment yield at four rates of sprayed polymers (0, 1, 3 and 5 g/m²), three rainfall intensities (1, 1.5 and 2 mm/min) and a slope gradient of 15° with a silt loam soil through simulated rain. The results showed that both Jag S and Jag C162 significantly increased the shear strength and improved the aggregates composition of the soil surface. The water-stable soil aggregates >0.25 mm increased from 9% to 50% with increasing rates of Jag S and Jag C162. Jag S and Jag C162 also effectively increased rainfall infiltration and final infiltration rate, and reduced erosion compared to controls without natural polymer derivatives added. However, higher rates of Jag S produced lower infiltration rates. Although both Jag S and Jag C162 effectively influenced soil physical properties and erosion, the effect of Jag C162 was more significant than that of Jag S.

  19. Influence of agronomic amendments on the fate of bound methyl parathion residues in soils

    International Nuclear Information System (INIS)

    Gerstl, Z.; Helling, C.S.

    1984-01-01

    The fate of [ring- 14 C] methyl parathion in a silt loam soil was monitored during a 49-day incubation period. At this point, 54% of the initial 14 C remained in the soil; of this, 13% was extractable with MeOH and 87% was bound residue. Soils were then treated with inorganic and organic amendments and incubated an additional 70 days. Release of methyl parathion bound residues could not be demonstrated, but mineralization of both bound and extractable 14 C to 14 CO 2 was seen. Slow, continuous production of CO 2 , all at comparable rates, occurred with the controls and with amendments H 2 SO 4 , (NH 4 ) 2 SO 4 , NH 4 OH, chitin, oat seedlings, and oat straw. Glucose and asparagine caused high rates of 14 CO 2 production. HgCl 2 gave very high initial rates of 14 CO 2 loss; the rate declined to that of the control only after 9-10 weeks. The lime treatment exceeded the controls after 1 week, declining only slightly with time. The effects of sewage sludge and dairy manure were similar to the controls except that: (a) sludge caused a very high initial loss of 14 CO 2 , and (b) both treatments gave an unaccountable loss of 14 C, perhaps as 14 CH 4 from anaerobic conditions. By 70 days, levels of extractable 14 C and bound 14 C had both declined twice as rapidly in certain amended soils as in unamended controls. (author)

  20. Increased mineral oil bioavailability in slurries by monovalent cation-induced dispersion

    International Nuclear Information System (INIS)

    Jonge, H. de; Verstraten, J.M.

    1995-01-01

    Bioavailability of apolar contaminants is an important limiting factor for microbial reclamation of polluted soils. This paper describes a laboratory study of the relation between microaggregate stability and bioavailability of mineral oil in soil-water slurries. The stability of microaggregates in slurries is regulated by the valence and surface affinity of the cations in the system, and by the complexing anion P 2 O 7 4- (metaphosphate). A silt loam, contaminated with a weathered gas oil, was collected from an oil refinery site. Degradation rates were monitored in small-scale incubations at solid:liquid ratios of 1:5 (w/w). The solution contained Ca, Na, or K as the dominant cation. The levels of nutrients and metaphosphate were varied. Biodegradation rates increased with the sequence Ca 2 treatment. Measurements of the particle size distribution the slurry showed that an increase in the finer fractions qualitatively correlated with enhanced biodegradation. This is a strong indication that dispersion of the microaggregates increased bioavailability of the contaminant

  1. Field evaluation of two shallow land burial trench cap designs for long-term stabilization and closure of waste repositories at Los Alamos, New Mexico

    International Nuclear Information System (INIS)

    Nyhan, J.; Drennon, B.; Hakonson, T.

    1989-02-01

    The results from several field experiments on methods to control soil erosion, biointrusion, and water infiltration were used to design and test a burial site cover which improves the ability of the disposal site to isolate the wastes. The performance of the improved cover design in managing water and biota at the disposal site was compared with a more conventional design widely used in the industry. The conventional trench cover design consists of 15 cm of sandy loam topsoil over 75 cm of sandy silt backfill, whereas the improved trench cover design consists of 75 cm of topsoil over a minimum of 25 cm of gravel and 90 cm of river cobble. Each plot was lined with an impermeable liner to allow for mass balance calculation of water dynamics and contains hydrologic tracer ions (iodide and bromide) to demonstrate movement of water through the various zones of the trench cap. Cesium was emplaced beneath the trench cap to indicate root penetration through the trench cap, observed by sampling plant samples collected on the plots and assaying them for cesium. The field data are summarized and discussed in terms of its usefulness for waste management decisions. 67 refs., 44 figs., 4 tabs

  2. Use of radioactive sodium-22 to study the processes of soil salinization and desalinization

    International Nuclear Information System (INIS)

    Alzubaidi, A.H.

    1979-01-01

    This study deals with the salinization of four undisturbed soil columns of silt loam soil, collected with special plexiglass columns. The salinization was effected by adding a certain volume of salt solution consisting of a mixture of NaCl, CaCl 2 and MgCl 2 and containing 0.5 mCi of sodium-22. The salt solution was added to the surface of the first two columns and then the soil columns were leached with distilled water, while for the other two columns, the salt solution was added from the bottom of the columns using a syphon technique. The first two columns represent a model for the desalinization process of saline soils, while the latter two columns represent a model for the salinization process under the effect of high groundwater table. The downward and upward movements of sodium through the soil columns were recorded by measuring sodium radioactivity periodically, using a special scanner which continuously and automatically detected the radioactivity of sodium with the help of a gamma spectrometer. The final distribution curves for sodium movement throughout these soil columns versus time were obtained by computer. The data obtained indicate that radioactive sodium can be used with success to study the movement of salts in soil. The results also bring a new and better understanding of the nature of the salt movement during the processes of salinization and desalinization, the most important soil processes in the arid and semi-arid regions. (author)

  3. Imaging and locating paleo-channels using geophysical data from meandering system of the Mun River, Khorat Plateau, Northeastern Thailand

    Directory of Open Access Journals (Sweden)

    Nimnate P.

    2017-12-01

    Full Text Available The Khorat Plateau from northeast Thailand, the upstream part of the Mun River flows through clastic sedimentary rocks. A massive amount of sand was transported. We aimed to understand the evolution of fluvial system and to discuss the advantages of two shallow geophysical methods for describing subsurface morphology of modern and paleo-channels. We applied Electrical Resistivity Tomography (ERT and Ground Penetrating Radar (GPR to characterize the lateral, vertical morphological and sedimentary structures of paleo-channels, floodplain and recent point bars. Both methods were interpreted together with on-sites boreholes to describe the physical properties of subsurface sediments. As a result, we concluded that four radar reflection patterns including reflection free, shingled, inclined and hummocky reflections were appropriated to apply as criteria to characterize lateral accretion, the meandering rivers with channel-filled sequence and floodplain were detected from ERT profiles. The changes in resistivity correspond well with differences in particle size and show relationship with ERT lithological classes. Clay, silt, sand, loam and bedrock were classified by the resistivity data. Geometry of paleo-channel embayment and lithological differences can be detected by ERT, whereas GPR provides detail subsurface facies for describing point bar sand deposit better than ERT.

  4. Tillage and Fertilizer Management Effects on Soil-Atmospheric Exchanges of Methane and Nitrous Oxide in a Corn Production System

    Directory of Open Access Journals (Sweden)

    Ermson Z. Nyakatawa

    2011-01-01

    Full Text Available Land application of poultry litter (PL presents an opportunity to improve soil productivity and disposal of poultry waste. We investigated methane (CH4 and nitrous oxide (N2O emissions from agricultural soil receiving PL and ammonium nitrate (AN fertilizers using surface (SA, soil incorporation (SI, and subsurface band (BA application methods in conventional (CT and no-tillage (NT systems on a Decatur silt loam soil in North Alabama. Plots under CT and NT were sinks of CH4 in spring, summer, and fall. In winter, the plots had net emissions of 3.32 and 4.24 g CH4 ha-1 day-1 in CT and NT systems, respectively. Plots which received AN were net emitters of CH4 and N2O, whereas plots which received PL were net sinks of CH4. Plots which received PL using SA or SI methods were net emitters of N2O, whereas under PL using BA application, the plots were net sinks of N2O. Our study indicates that using subsurface band application of PL was the most promising environmentally sustainable poultry waste application method for reducing CH4 and N2O emissions from agricultural soil in NT and CT corn production systems on the Decatur soil in north Alabama.

  5. Runoff water quality from broiler litter-amended tall fescue in response to natural precipitation in the Ozark Highlands.

    Science.gov (United States)

    Menjoulet, B C; Brye, K R; Pirani, A L; Haggard, B E; Gbur, E E

    2009-01-01

    The Arkansas poultry industry produced more than 1.2 billion broiler chickens (Gallus gallus domesticus) and generated approximately 1.3 million Mg of broiler litter in 2002. High transportation costs of relocating broiler litter have led to annual land applications near poultry houses, increasing concern for potential surface water contamination from runoff. The objective of this study was to evaluate the effect of broiler litter application rate on runoff water quality in response to natural precipitation. Six plots (1.5 by 6.0 m), located on a Captina silt loam (finesilty, siliceous, active, mesic Typic Fragiudult), were amended with fresh broiler litter at 0, 5.6, and 11.2 Mg ha(-1) (control, low, and high litter treatments, respectively) once annually for 4 yr (May 2003 through April 2007). Runoff collected after each runoff-producing event was analyzed for soluble nutrients and metals. Cumulative runoff did not differ among litter treatments over the 4-yr study. At times, flow-weighted mean (FWM) concentrations of As from all litter treatments exceeded the maximum contaminant level for drinking water (0.01 mg As L(-1)). Four-year FWM Fe concentrations and runoff losses were greater (P precipitation is temporally variable, evaluating runoff water quality in response to natural precipitation over several years is key to ascertaining the long-term impacts of surface-applied soil amendments like broiler litter.

  6. Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

    Directory of Open Access Journals (Sweden)

    Popović Zorica

    2010-01-01

    Full Text Available Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C (soil water regime in pots was maintained at the level of field water capacity and treated (water-stressed, WS (soil water regime was maintained in the range of wilting point and lentocapillary capacity. The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively, which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively. Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½. Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.

  7. Nitrogen cycling in a flooded-soil ecosystem planted to rice (Oryza sativa L.)

    International Nuclear Information System (INIS)

    Reddy, K.R.

    1982-01-01

    15 N studies of various aspects of the nitrogen cycle in a flooded rice ecosystem on Crowley silt loam soil in Louisiana were reviewed to construct a mass balance model of the nitrogen cycle for this system. Nitrogen transformations modeled included 1) net ammonification (0.22 mg NH 4+ -N kg dry soil - 1 day - 1 ). 2) net nitrification (207 mg NO 3- -N kg dry soil - 1 day - 1 ). 3) denitrification (0.37 mg N kg dry soil - 1 day - 1 ), and 4) biological N 2 fixation (0.16 mg N kg dry soil - 1 day - 1 ). Nitrogen inputs included 1) application of fertilizers, 2) incorporation of crop residues, 3) biological N 2 fixation, and 4) deposition. Nitrogen outputs included 1) crop removal, 2) gaseous losses from NH 3 volatilization and simultaneous occurrence of nitrification-denitrification, and 3) leaching and runoff. Mass balance calculations indicated that 33% of the available inorganic nitrogen was recovered by rice, and the remaining nitrogen was lost from the system. Losses of N due to ammonia volatilization were minimal because fertilizer-N was incorporated into the soil. A significant portion of inorganic-N was lost by ammonium diffusion from the anaerobic layer to the aerobic layer in response to a concentration gradient and subsequent nitrification in the aerobic layer followed by nitrate diffusion into the anaerobic layer and denitrification into gaseous end products. Leaching and surface runoff losses were minimal. (orig.)

  8. Efficacy of Natural Polymer Derivatives on Soil Physical Properties and Erosion on an Experimental Loess Hillslope

    Directory of Open Access Journals (Sweden)

    Jun’e Liu

    2017-12-01

    Full Text Available Raindrops disperse large soil aggregates into smaller particles, which can clog soil pores, cause soil crusting, reduce rainfall infiltration and increase soil loss. It was found that natural polymer derivatives were effective in improving soil physical properties and decreasing soil erosion on an experimental loess hillslope. This study investigated the effect of new natural polymer derivatives (Jag S and Jag C162 on soil properties, rainfall infiltration and sediment yield at four rates of sprayed polymers (0, 1, 3 and 5 g/m2, three rainfall intensities (1, 1.5 and 2 mm/min and a slope gradient of 15° with a silt loam soil through simulated rain. The results showed that both Jag S and Jag C162 significantly increased the shear strength and improved the aggregates composition of the soil surface. The water-stable soil aggregates >0.25 mm increased from 9% to 50% with increasing rates of Jag S and Jag C162. Jag S and Jag C162 also effectively increased rainfall infiltration and final infiltration rate, and reduced erosion compared to controls without natural polymer derivatives added. However, higher rates of Jag S produced lower infiltration rates. Although both Jag S and Jag C162 effectively influenced soil physical properties and erosion, the effect of Jag C162 was more significant than that of Jag S.

  9. Efficacy of Natural Polymer Derivatives on Soil Physical Properties and Erosion on an Experimental Loess Hillslope

    Science.gov (United States)

    Liu, Jun’e; Wang, Zhanli; Li, Yuanyuan

    2017-01-01

    Raindrops disperse large soil aggregates into smaller particles, which can clog soil pores, cause soil crusting, reduce rainfall infiltration and increase soil loss. It was found that natural polymer derivatives were effective in improving soil physical properties and decreasing soil erosion on an experimental loess hillslope. This study investigated the effect of new natural polymer derivatives (Jag S and Jag C162) on soil properties, rainfall infiltration and sediment yield at four rates of sprayed polymers (0, 1, 3 and 5 g/m2), three rainfall intensities (1, 1.5 and 2 mm/min) and a slope gradient of 15° with a silt loam soil through simulated rain. The results showed that both Jag S and Jag C162 significantly increased the shear strength and improved the aggregates composition of the soil surface. The water-stable soil aggregates >0.25 mm increased from 9% to 50% with increasing rates of Jag S and Jag C162. Jag S and Jag C162 also effectively increased rainfall infiltration and final infiltration rate, and reduced erosion compared to controls without natural polymer derivatives added. However, higher rates of Jag S produced lower infiltration rates. Although both Jag S and Jag C162 effectively influenced soil physical properties and erosion, the effect of Jag C162 was more significant than that of Jag S. PMID:29271899

  10. Cultural Resources Review for Closure of the nonradioactive Dangerous Waste Landfill and Solid Waste Landfill in the 600 Area, Hanford Site, Benton County, Washington, HCRC# 2010-600-018R

    Energy Technology Data Exchange (ETDEWEB)

    Gutzeit, Jennifer L.; Kennedy, Ellen P.; Bjornstad, Bruce N.; Sackschewsky, Michael R.; Sharpe, James J.; DeMaris, Ranae; Venno, M.; Christensen, James R.

    2011-02-02

    The U.S. Department of Energy Richland Operations Office is proposing to close the Nonradioactive Dangerous Waste Landfill (NRDWL) and Solid Waste Landfill (SWL) located in the 600 Area of the Hanford Site. The closure of the NRDWL/SWL entails the construction of an evapotranspiration cover over the landfill. This cover would consist of a 3-foot (1-meter) engineered layer of fine-grained soil, modified with 15 percent by weight pea gravel to form an erosion-resistant topsoil that will sustain native vegetation. The area targeted for silt-loam borrow soil sits in Area C, located in the northern central portion of the Fitzner/Eberhardt Arid Lands Ecology (ALE) Reserve Unit. The pea gravel used for the mixture will be obtained from both off-site commercial sources and an active gravel pit (Pit #6) located just west of the 300 Area of the Hanford Site. Materials for the cover will be transported along Army Loop Road, which runs from Beloit Avenue (near the Rattlesnake Barricade) east-northeast to the NRDWL/SWL, ending at State Route 4. Upgrades to Army Loop Road are necessary to facilitate safe bidirectional hauling traffic. This report documents a cultural resources review of the proposed activity, conducted according to Section 106 of the National Historic Preservation Act of 1966.

  11. Inverse Modeling of Soil Hydraulic Parameters Based on a Hybrid of Vector-Evaluated Genetic Algorithm and Particle Swarm Optimization

    Directory of Open Access Journals (Sweden)

    Yi-Bo Li

    2018-01-01

    Full Text Available The accurate estimation of soil hydraulic parameters (θs, α, n, and Ks of the van Genuchten–Mualem model has attracted considerable attention. In this study, we proposed a new two-step inversion method, which first estimated the hydraulic parameter θs using objective function by the final water content, and subsequently estimated the soil hydraulic parameters α, n, and Ks, using a vector-evaluated genetic algorithm and particle swarm optimization (VEGA-PSO method based on objective functions by cumulative infiltration and infiltration rate. The parameters were inversely estimated for four types of soils (sand, loam, silt, and clay under an in silico experiment simulating the tension disc infiltration at three initial water content levels. The results indicated that the method is excellent and robust. Because the objective function had multilocal minima in a tiny range near the true values, inverse estimation of the hydraulic parameters was difficult; however, the estimated soil water retention curves and hydraulic conductivity curves were nearly identical to the true curves. In addition, the proposed method was able to estimate the hydraulic parameters accurately despite substantial measurement errors in initial water content, final water content, and cumulative infiltration, proving that the method was feasible and practical for field application.

  12. Sorption and leaching of benzalkonium chlorides in agricultural soils.

    Science.gov (United States)

    Khan, Adnan Hossain; Macfie, Sheila M; Ray, Madhumita B

    2017-07-01

    The adsorption and leaching characteristics of two commonly used benzalkonium chlorides (BACs), benzyl dimethyl dodecyl ammonium chloride (BDDA) and benzyl dimethyl tetradecyl ammonium chloride (BDTA) using three agricultural soils with varied proportions of silt, sand, clay, and organic matter were determined. BACs are cationic surfactants used in large quantities for sanitary and personal care products and are abundant in environmental samples. Adsorption isotherm data (aqueous concentration in the range of 25-150 mg L -1 ) fitted the Langmuir model better than the Freundlich model. BDTA with a longer alkyl chain adsorbed more to soil compared to BDDA, and the soil with the highest percentage of clay adsorbed the most. Column tests conducted using soils amended with lime stabilised biosolids and artificial rain water at a flow rate of 0.2 mL min -1 indicate very low leaching of BACs. Less than 1% of the available BDDA leached through sandy loam soil column with a depth of 9 cm. Therefore, the possibility of BACs to become bioavailable through leaching is very low at environmentally relevant concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Acidification of forest soil in Russia: From 1893 to present

    Science.gov (United States)

    Lapenis, A.G.; Lawrence, G.B.; Andreev, A.A.; Bobrov, A.A.; Torn, M.S.; Harden, J.W.

    2004-01-01

    It is commonly believed that fine-textured soils developed on carbonate parent material are well buffered from possible acidification. There are no data, however, that document resistance of such soils to acidic deposition exposure on a timescale longer than 30-40 years. In this paper, we report on directly testing the long-term buffering capacity of nineteenth century forest soils developed on calcareous silt loam. In a chemical analysis comparing archived soils with modern soils collected from the same locations ???100 years later, we found varying degrees of forest-soil acidification in the taiga and forest steppe regions. Land-use history, increases in precipitation, and acidic deposition were contributing factors in acidification. The acidification of forest soil was documented through decreases in soil pH and changes in concentrations of exchangeable calcium and aluminum, which corresponded with changes in communities of soil microfauna. Although acidification was found at all three analyzed locations, the trends in soil chemistry were most pronounced where the highest loading of acidic deposition had taken place. Copyright 2004 by the American Geophysical Union.

  14. Nitrogen utilization and environmental losses in organic greenhouse lettuce amended with two distinct biochars.

    Science.gov (United States)

    Pereira, Engil Isadora Pujol; Conz, Rafaela Feola; Six, Johan

    2017-11-15

    The potential of biochar to prevent nitrogen (N) losses and improve plant performance were studied across various levels of N input for two growing seasons in mesocosms simulating an organic lettuce production system. A silt loam soil was amended with pine chip (PC) and walnut shell (WS) biochar (10tha -1 ) in combination with five organic N fertilization rates (0, 56, 112, 168, and 225kgNha -1 ). The N output through harvest, leachate, and N 2 O emissions were measured to assess N utilization and environmental losses of biochar-amended soils. For both biochars, only at the 100% N fertilization rate was lettuce biomass production improved with significant increases in N use efficiency (NUE); however, only PC biochar decreased N losses via leaching (at 100% N fertilization rate) and seasonal N 2 O emissions (at 50% N fertilization rate). Thus, due to increases in plant biomass and decreases in N losses, PC biochar significantly decreased the ratio of N lost over N exported in biomass. Findings from this study suggest that both WS and PC biochars can improve organic lettuce production but only at 225kgNha -1 . Decreases in N losses via leachate and N 2 O emissions vary with fertilization level and biochar type. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Effect of organic fertilizers derived dissolved organic matter on pesticide sorption and leaching

    International Nuclear Information System (INIS)

    Li Kun; Xing Baoshan; Torello, William A.

    2005-01-01

    Incorporation of organic fertilizers/amendments has been, and continues to be, a popular strategy for golf course turfgrass management. Dissolved organic matter (DOM) derived from these organic materials may, however, facilitate organic chemical movement through soils. A batch equilibrium technique was used to evaluate the effects of organic fertilizer-derived DOM on sorption of three organic chemicals (2,4-D, naphthalene and chlorpyrifos) in USGA (United States Golf Association) sand, a mixed soil (70% USGA sand and 30% native soil) and a silt loam soil (Typic Fragiochrept). DOM was extracted from two commercial organic fertilizers. Column leaching experiments were also performed using USGA sand. Sorption experiments showed that sorption capacity was significantly reduced with increasing DOM concentration in solution for all three chemicals. Column experimental results were consistent with batch equilibrium data. These results suggest that organic fertilizer-derived DOM might lead to enhanced transport of applied chemicals in turf soils. - Dissolved organic matter could result in enhanced transport of chemicals applied to turf

  16. Selection of Computer Codes for Shallow Land Waste Disposal in PPTA Serpong

    International Nuclear Information System (INIS)

    Syahrir

    1996-01-01

    Selection of Computer Codes for Shallow Land Waste Disposal in PPTA Serpong. Models and computer codes have been selected for safety assessment of near surface waste disposal facility. This paper provides a summary and overview of the methodology and codes selected. The methodology allows analyses of dose to individuals from offsite releases under normal conditions as well as on-site doses to inadvertent intruders. A demonstration in the case of shallow land waste disposal in Nuclear Research Establishment are in Serpong has been given for normal release scenario. The assessment includes infiltration of rainfall, source-term, ground water (well) and surface water transport, food-chain and dosimetry. The results show dose history of maximally exposed individuals. The codes used are VS2DT, PAGAN and GENII. The application of 1 m silt loam as a moisture barrier cover decreases flow in the disposal unit by a factor of 27. The selected radionuclides show variety of dose histories according to their chemical and physical characteristics and behavior in the environment

  17. Assessing PAH removal from clayey soil by means of electro-osmosis and electrodialysis

    KAUST Repository

    Lima, Ana T.

    2012-10-01

    Polycyclic aromatic hydrocarbons (PAH) are persistent and toxic contaminants which are difficult to remove from fine porous material like clayey soils. The present work aims at studying two electroremediation techniques for the removal of PAHs from a spiked natural silt soil from Saudi Arabia and a silty loam soil from The Netherlands which has been exposed to tar contamination for over 100. years. The two techniques at focus are electro-osmosis and electrodialysis. The latter is applied for the first time for the removal of PAH. The efficiency of the techniques is studied using these two soils, having been subjected to different PAH contact times. Two surfactants were used: the non-ionic surfactant Tween 80 and anionic surfactant sodium dodecyl sulphate (SDS) to aid desorption of PAHs from the soil. Results show a large discrepancy in the removal rates between spiked soil and long-term field contaminated soil, as expected. In spiked soil, electro-osmosis achieves up to 85% while electrodialysis accomplishes 68% PAH removal. In field contaminated soil, electro-osmosis results in 35% PAH removal whereas electrodialysis results in 79%. Short recommendations are derived for the up-scale of the two techniques. © 2012.

  18. Sensitivity Analysis and Identification of Parameters to the Van Genuchten Equation

    Directory of Open Access Journals (Sweden)

    Guangzhou Chen

    2016-01-01

    Full Text Available Van Genuchten equation is the soil water characteristic curve equation used commonly, and identifying (estimating accurately its parameters plays an important role in the study on the movement of soil water. Selecting the desorption and absorption experimental data of silt loam from a northwest region in China as an instance, Monte-Carlo method was firstly applied to analyze sensitivity of the parameters and uncertainty of model so as to get the key parameters and posteriori parameter distribution to guide subsequent parameter identification. Then, the optimization model of the parameters was set up, and a new type of intelligent algorithm-difference search algorithm was employed to identify them. In order to overcome the fault that the base difference search algorithm needed more iterations and to further enhance the optimization performance, a hybrid algorithm, which coupled the difference search algorithm with simplex method, was employed to identification of the parameters. By comparison with other optimization algorithms, the results show that the difference search algorithm has the following characteristics: good optimization performance, the simple principle, easy implement, short program code, and less control parameters required to run the algorithm. In addition, the proposed hybrid algorithm outperforms the basic difference search algorithm on the comprehensive performance of algorithm.

  19. The effect of different nitrogen fertilization rates on yield and quality of marigold (Calendula officinalis L. 'Tokaj' raw material

    Directory of Open Access Journals (Sweden)

    Beata Król

    2012-12-01

    Full Text Available Pot marigold (Calendula officinalis L. is an annual ornamental plant which is also grown for herbal raw material (flower heads used in the pharmaceutical and cosmetic industries. A field experiment was carried out in the years 2006-2008 in the Experimental Farm of the University of Life Sciences in Lublin. The study was conducted on loess soil with the granulometric composition of silt loam. The aim of the experiment was to determine the effect of different nitrogen rates (0, 40, 80, 120, 160 kg N × ha-1 on some morphological features of flower heads as well as on yield and quality of pot marigold raw material. Flowering of pot marigold was shortest in the control treatment (32 days and longest (43 days in the plot where nitrogen fertilization had been applied at the highest rate (160 kg N × ha-1. Nitrogen fertilization had a significant influence on the number of flower heads per plant, but no significant difference was found in diameter as well as in ligulate flowers and tubular flowers in the flower head. It was found to increase significantly raw material yield after the application of 80 kg N × ha-1, compared to the control treatment. Yield of flower heads did not differ markedly for fertilization rates from 80 to 160 kg N × ha-1. Nitrogen fertilization modified slightly essential oil content (this content increased with increasing nitrogen rates, but at the same time it decreased the percentage of flavonoid compounds.

  20. THE ROLE OF KETTLE HOLES AS LOCAL SEDIMENTARY RESERVOIRS OF THE EARLY POST-GLACIAL LANDSCAPE OF SUWAŁKI LANDSCAPE PARK

    Directory of Open Access Journals (Sweden)

    Krzysztof Micun

    2014-11-01

    Full Text Available The study is an attempt to determine the size of sedimentation at the bottoms of the small kettle holes of Suwałki Landscape Park as well as the deposits that fill them. The size and the type of the transformations occurring in the kettle holes during the Holocene were determined on the basis of conducted analyses. The presence of allochtonic mineral deposits and autochtonic lacustrine and biogenic deposits was affirmed. The first group consisted of loam colluvium with a maximum thickness of up to 1m. The other one contains lacustrine clays and silts with a maximum thickness of several tens of centimeters and gytjas and peats with a total thickness of up to 9 m. Sediments’ sequence in Snołda, Łuśnin and Linówek depressions indicated a secondary nature of the colluvium deposition in relations to the biogenic acumulation that took place throughout the Holocene. Hillslope sediments accumulation intensified only in times of economic activity growth in the area. Steep gradients of slopes and considerable depth of kettle holes favor the development of hillslope processes. The material accumulated in the depressions remains immobilised. This limits the spatial extent of the denudation and thus stabilises the morphology of early post-glacial landscape.

  1. Adsorption and desorption characteristic of benzimidazole based fungicide carbendazim in pakistani soils

    International Nuclear Information System (INIS)

    Ahmad, K.S.; Rashid, N.; Tazaiyen, S.; Nazar, M.F.

    2013-01-01

    A versatile cost-effective Benzimidazole based fungicide, Carbendazim (methyl 1H-benzimidazole-2 carboxylate ) has been utilized to investigate its sorption-desorption behaviour on physicochemical properties of geographical soils, ranging from hilly to desert areas of Pakistan, via batch equilibrium method. The data obtained in all tests showed that adsorption co-efficient isotherm for Carbendazim in four tested soil were well fitted the freundlich equation. Distribution co-efficient (K d ) parameters are low (3.59 to 11.60 ml micro g/sup -1/) indicating low adsorption. It was observed that Carbendazim showed a relatively greater degree of adsorption on soil samples (Soil 4) that were collected from northern hilly areas Ayubia, Khyber Pakhton khaw (KPK) (Silt loam) i.e.11.60 ml mu g/sup -1/ and least adsorption on sandy Soil of Multan Punjab(Soil 2). While other two soils 1 were collected from Murree region, a boarder of Punjab and KPK mountain area and Soil 3 from Tarnol, Islamabad. Desorption studies reveal that the adsorbed fungicide is firmly retained by soil particles and their adsorption are almost irreversible. The results indicate that soil organic matter (SOM) and appropriate pH also play key role in sorption capacity. (author)

  2. Assessing PAH removal from clayey soil by means of electro-osmosis and electrodialysis

    KAUST Repository

    Lima, Ana T.; Ottosen, Lisbeth M.; Heister, Katja; Loch, J.P. Gustav

    2012-01-01

    Polycyclic aromatic hydrocarbons (PAH) are persistent and toxic contaminants which are difficult to remove from fine porous material like clayey soils. The present work aims at studying two electroremediation techniques for the removal of PAHs from a spiked natural silt soil from Saudi Arabia and a silty loam soil from The Netherlands which has been exposed to tar contamination for over 100. years. The two techniques at focus are electro-osmosis and electrodialysis. The latter is applied for the first time for the removal of PAH. The efficiency of the techniques is studied using these two soils, having been subjected to different PAH contact times. Two surfactants were used: the non-ionic surfactant Tween 80 and anionic surfactant sodium dodecyl sulphate (SDS) to aid desorption of PAHs from the soil. Results show a large discrepancy in the removal rates between spiked soil and long-term field contaminated soil, as expected. In spiked soil, electro-osmosis achieves up to 85% while electrodialysis accomplishes 68% PAH removal. In field contaminated soil, electro-osmosis results in 35% PAH removal whereas electrodialysis results in 79%. Short recommendations are derived for the up-scale of the two techniques. © 2012.

  3. Effect of a non-ionic surfactant added to the soil structure on the biodegradation of aromatic hydrocarbons within the soil

    Energy Technology Data Exchange (ETDEWEB)

    Aronstein, B N [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States); Alexander, M [Lab. of Soil Microbiology, Dept. of Soil, Crop, and Atmospheric Sciences, Cornell Univ., Ithaca, NY (United States)

    1993-06-01

    A study was conducted to determine whether a non-ionic surfactant (Novel II 1412-56) added to the surface of Lima silt loam would enhance the biodegradation of penanthrene and biphenyl present within the soil. Water containing the surfactant at concentrations of 10 and 100 [mu]g/ml was pumped through the soil. At 10 [mu]g/ml, Novel II 1412-56 markedly enhanced the rate and extent of phenanthrene mineralization and the extent but not the initial rate of biphenyl mineralization. The stimulation was less if the water added to the soil surface contained 100 [mu]g surfactant/ml. Addition of the surfactant at the two concentrations did not result in leaching of either phenanthrene or biphenyl, but products of the degradation were found in the soil leachate with or without the surfactant. We suggest that surfactants at low concentrations may be useful for in-situ bioremediation of sites contaminated with hydrophobic pollutants without causing movement of the parent compounds to ground-waters. (orig.)

  4. Basic exchangeable cations in Finnish mineral soils

    Directory of Open Access Journals (Sweden)

    Armi Kaila

    1972-09-01

    Full Text Available The content of exchangeable Ca, Mg, K and Na replaced by neutral ammonium acetate was determined in 470 samples of mineral soils from various parts of Finland, except from Lapland. The amount of all these cations tended to increase with an increase in the clay content, but variation within each textural class was large, and the ranges usually overlapped those of the other classes. The higher acidity of virgin surface soils was connected with a lower average degree of saturation by Ca as compared with the corresponding textural classes of cultivated soils. No significant difference in the respective contents of other cations was detected. The samples of various textural groups from deeper layers were usually poorer in exchangeable Ca and K than the corresponding groups of plough layer. The mean content of exchangeable Mg was equal or even higher in the samples from deeper layers than in the samples from plough layer, except in the group of sand soils. The percentage of Mg of the effective CEC increased, as an average, from 9 in the sand and fine sand soils of plough layer to 30 in the heavy clay soils; in the heavy clay soils from deeper layers its mean value was 38 ± 4 %. In the samples of plough layer, the mean ratio of Ca to Mg in sand and fine sand soils was about 9, in silt and loam soils about 6, in the coarser clay soils about 4, and in heavy clay about 2.

  5. Download this PDF file

    African Journals Online (AJOL)

    OLUWOLE

    included clay, silt, silt + clay and silt/clay ratio (SCR), whereas fine sand and saturated hydraulic conductivity were highly .... Semivariance was calculated using: ( ). ( ). ( ) (. ) .... outliers did not dominate the measure of central tendency. Shulka et ...

  6. Estimating the saturated soil hydraulic conductivity by the near steady-state phase of a beerkan infiltration run

    Science.gov (United States)

    Di Prima, Simone; Bagarello, Vincenzo; Iovino, Massimo

    2017-04-01

    soils (sand, S; loamy sand, LS; sandy loam, SAL; loam, L; silt loam, SIL and silty clay loam, SCL) from UNSODA database and different initial water contents. Comparison with other existing procedures were also carried out. The SSBI method allowed accurate estimation of saturated soil hydraulic conductivity of both field and analytically generated data. For analytically generated data, the most accurate predictions were obtained with the method 2 by Wu et al. (1999) for the S and LS soils (prediction errors not exceeding 3.8%) and with the SSBI method for the other four soils (error Taha, A., Ross, P., Angulo-Jaramillo, R., 1996. Hydrological and thermal behaviour of the vadose zone in the area of Barrax and Tomelloso (Spain): Experimental study, analysis and modeling. Project UE n. EV5C-CT 92, 00-90. Lassabatere, L., Angulo-Jaramillo, R., Soria Ugalde, J.M., Cuenca, R., Braud, I., Haverkamp, R., 2006. Beerkan Estimation of Soil Transfer Parameters through Infiltration Experiments—BEST. Soil Science Society of America Journal 70, 521. doi:10.2136/sssaj2005.0026 Reynolds, W.D., Elrick, D.E., 1990. Ponded Infiltration From a Single Ring: I. Analysis of Steady Flow. Soil Science Society of America Journal 54, 1233. doi:10.2136/sssaj1990.03615995005400050006x Wu, L., Pan, L., Mitchell, J., Sanden, B., 1999. Measuring Saturated Hydraulic Conductivity using a Generalized Solution for Single-Ring Infiltrometers. Soil Science Society of America Journal 63, 788. doi:10.2136/sssaj1999.634788x Yilmaz, D., Lassabatere, L., Angulo-Jaramillo, R., Deneele, D., Legret, M., 2010. Hydrodynamic Characterization of Basic Oxygen Furnace Slag through an Adapted BEST Method. Vadose Zone Journal 9, 107. doi:10.2136/vzj2009.0039

  7. Sensitivity analysis and metamodeling of a toolchain of models to help sizing vetetative filter strips in a watershed.

    Science.gov (United States)

    Lauvernet, Claire; Noll, Dorothea; Muñoz-Carpena, Rafael; Carluer, Nadia

    2014-05-01

    agricultural field and the VFS characteristics. These scenarios are based on: 2 types of climates (North and South-west of France), different rainfall intensities and durations, different lengths and slopes of hillslope, different humidity conditions, 4 soil types (silt loam, sandy loam, clay loam, sandy clay loam), 2 crops (wheat and corn) for the contributive area, 2 water table depths (1m and 2.5m) and 4 soil types for the VFS. The sizing method was applied for all these scenarios, and a sensitivity analysis of the VFS optimal length was performed for all the input parameters in order to understand their influence, and to identify for which a special care has to be given. Based on that sensitivity analysis, a metamodel has been developed. The idea is to simplify the whole toolchain and to make it possible to perform the buffer sizing by using a unique tool and a smaller set of parameters, given the available information from the end users. We first compared several mathematical methods to compute the metamodel, and then validated them on an agricultural watershed with real data in the North-West of France.

  8. Long-term influence of tillage and fertilization on net carbon dioxide exchange rate on two soils with different textures.

    Science.gov (United States)

    Feiziene, Dalia; Feiza, Virginijus; Slepetiene, Alvyra; Liaudanskiene, Inga; Kadziene, Grazina; Deveikyte, Irena; Vaideliene, Asta

    2011-01-01

    The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO exchange rate (NCER) and environmental factors (SOC, soil temperature [T], and water content [W]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  9. Muusikamaailm : Messiaeni mälestusfestival. Masuri lahkumiskontserdid USAs. Kolmest kaotusest / Priit Kuusk

    Index Scriptorium Estoniae

    Kuusk, Priit, 1938-

    2002-01-01

    Olivier Messiaeni mälestusfestivalist "musik sehen, licht hören". Kurt Masur lahkub New Yorgi Filharmoonia orkestri peadirigendi ametist. Teated Xavier Montsalvatge, Dorothy DeLay ja Dzhansug Kahhidze surmast

  10. The vulnerable Osprey breeding population of the Al Hoceima ...

    African Journals Online (AJOL)

    The vulnerable Osprey breeding population of the Al Hoceima National Park, Morocco: present status and threats. Flavio Monti, Houssine Nibani, Jean-Marie Dominici, Hamid Rguibi Idrissi, Mathieu Thévenet, Pierre-Christian Beaubrun, Olivier Duriez ...

  11. The conceptual design and development of Novel low cost sensors for measuring the relative light emission in the pre-millisecond stages detonating explosive charges

    CSIR Research Space (South Africa)

    Olivier, M

    2012-12-01

    Full Text Available Thesis December 2012/ Stellenbosch University The conceptual design and development of Novel low cost sensors for measuring the relative light emission in the pre-millisecond stages detonating explosive charges Olivier M CSIR. Defence, Peace...

  12. Novel antibacterial activity of Terfizia claveryi aqueous extract ...

    African Journals Online (AJOL)

    Admin

    2013-10-30

    Oct 30, 2013 ... diseases in both humans and animals and can lead to blindness (Olivier ... 4°C. The supernatant was considered as crude aqueous extract of ..... with use of chloramphenicol eye drops in British general practice database.

  13. "Berlinale" võistluslainelt / Endel Link

    Index Scriptorium Estoniae

    Link, Endel

    2007-01-01

    Lühidalt 57. Berliini filmifestivalil linastuvatest filmidest. Avafilm on Olivier Dahani "La Mome" Edith Piafist. Lastefilmide võistlusprogrammis on ka "Leiutajateküla Lotte". Riina Sildos on lühifilmide žüriis

  14. European Conference on Molecular Biology EMBO

    CERN Multimedia

    1967-01-01

    European Conference on Molecular Biology, which eventually led to the setting up of EMBO, was held at CERN in April. Olivier Reverdin is adressing the delegates. Bernard Gregory is on the left and Willy Spuhler in the centre.

  15. A multi-purpose technology

    CERN Multimedia

    Alizée Dauvergne

    2010-01-01

    Today, printed circuit boards – PCBs - are part and parcel of our everyday lives. We find them everywhere: in our computers, mobile phones, food processors, cars, radios, remote controls, etc. Although the associated technology no longer holds any secrets for us, its uses don't end here. Olivier Pizzirusso and his team are using the techniques involved in PCB manufacture to build the particle detectors of the future.   Rui de Oliveira (left) and Olivier Pizzirusso (right) in the workshop of Building 102. For the past five years Olivier Pizzirusso has worked at CERN as a technician specialising in the design and production of new-generation gas detectors known as Micro Pattern Gas Detectors (MPGDs). "Our workshop is in Building 102, where the standard PCBs used in the Laboratory are made by CERN's industrial service contractors", explains Olivier. The workshop houses drills, UV exposure units, presses and various other equipment needed for the manufacture of PC...

  16. Signature of a Collaboration agreement between Unitar & CERN.

    CERN Multimedia

    Pierre Gildemyn

    2012-01-01

    Signature of agreement with Mr Carlos Lopes (UNITAR) and Prof Rolf Heuer (CERN). From left to right : Einar Bjorgo, Francesco Pisano, Calors Lopes, Rolf Heuer, Maurizio Bona, Frédéric Hemmer, Olivier Van Damme

  17. Interspecific competition between Sitophilus zeamais and Sitotroga cerealella in a patchy environment

    DEFF Research Database (Denmark)

    Nykjær Larsen, Marie; Nachman, Gösta Støger; Skovgaard, Henrik

    2005-01-01

    The maize weevil, Sitophilus zeamais (Motchulsky) (Coleoptera: Curculionidae), and the Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), are important insect pests of stored products. The coexistence in nature of the two species on maize has been difficult to explai...

  18. Etjud v bagrovõhh tonahh - 2 / Mihhail Shtsherbakov

    Index Scriptorium Estoniae

    Shtsherbakov, Mihhail

    2005-01-01

    Prantsuse ajakirjanik ja kirjanik Jean-Christophe Grange ja tema raamatutest saanud filmid. Pikemalt põnevikust "Crimson Rivers 2"/"Rivieres pourpres II" : režissöör Olivier Dahan : Prantsusmaa - Itaalia - Suurbritannia 2004

  19. Dragotsennaja osen / Tatjana Barmakova

    Index Scriptorium Estoniae

    Barmakova, Tatjana

    2004-01-01

    Moefirmade Dior, Yves Saint Laurent (jumestuskunstnik Linda Cantello), Guerlain (kunstnik Olivier Echaudemaison), Shiseido (kunstnik Tom Pecheux) meigikollektsioonidest. Diori, Kenzo ja Thierry Mugleri uutest parfüümidest. "Kenzoairi" parfüümipudeli disainis klaasikunstnik Laura de Santillana

  20. The bee and the turtle : a fable from Yasuní National Park

    OpenAIRE

    Dangles, Olivier; Casas, J.

    2012-01-01

    A chance observation of an interaction between two very different species while exploring the Ecuadorean Amazon reminds Olivier Dangles and Jérôme Casas of the importance of natural history observations in developing ecological theories.

  1. Vegetative propagation of twelve fodder tree species indigenous to ...

    African Journals Online (AJOL)

    Vegetative propagation of twelve fodder tree species indigenous to the Sahel, West Africa. Catherine Ky-Dembele, Jules Bayala, Antoine Kalinganire, Fatoumata Tata Traoré, Bréhima Koné, Alain Olivier ...

  2. A new record of two penaeid species from Goa Coast

    Digital Repository Service at National Institute of Oceanography (India)

    Achuthankutty, C.T.; Nair, S.R.S.

    Adults of Penaeus japonicus (Bate) and juveniles of P. canaliculatus (Olivier) were recorded for the first time from the coastal estuarine regions of Goa, (India) respectively. Their presence in Goa waters suggests that both the species have a wide...

  3. International Relations as Group Interaction: The Case of Russia and NATO

    Science.gov (United States)

    2016-05-01

    Olivier Kempf, L’OTAN Au XXIe Siècle: La Transformation D’un Héritage, Histoire et Société (Perpignan: Artège, 2010), 277 4 Founding Act on Mutual...Press, 1976. Kempf, Olivier. L’OTAN Au XXIe Siècle: La Transformation D’un Héritage. Histoire et Société. Perpignan: Artège, 2010. Khong, Yuen Foong

  4. Variability in uptake of Cs isotopes by fenugreek plant from three soils

    Energy Technology Data Exchange (ETDEWEB)

    Pulhani, V; Dafauti, S; Dahiya, S; Hedge, A G [Environmental Studies Section, Health Physics Div., Bhabha Atomic Research Centre, Mumbai (India)

    2008-07-01

    Soil to plant transfer via root uptake is one of the major compartments in the radionuclide transfer pathways to man and can be used to assess the internal radiation dose via ingestion. The variability in the Transfer Factor (TF) of Cs isotopes was investigated in three different soils from nuclear power plant sites at Rajasthan and Narora with alkaline sandy loam alluvial and Madras with acidic coastal sandy loam alluvial soil. The soils were characterized for soil properties like texture, pH, EC, organic carbon, CaCO{sub 3} (%), CEC, silt, clay sand etc. and spiked with a mixture of 800 Bq {sup 137}Cs, 300 Bq {sup 134}Cs and 10mg of {sup 133}Cs (stable). Fenugreek (Trigonella foenum-graecum L.) from Leguminosae family an annual plant commonly used as a vegetable was grown in these soils to study the uptake of Cs. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. The uptake of heavy toxic elements like Pb, Cd, Ni, Cr etc. and nutrients Fe, Co, Cu, Zn, Mn, Ca, Mg, Na and K was also studied. {sup 137}Cs and{sup 134}Cs was estimated using HPGe detector (15% Relative Efficiency, 54cc-coaxial, 2keV resolution at 1332keV of {sup 60}Co). Stable Cs, K and Na were determined by the Atomic Emission Spectrophotometry and Pb, Cd, Cr etc. by Atomic Absorption Spectrophotometry. Among the three soils the transfer factor for all the elements and Cs was highest for MAPS due to higher organic matter content and acidic pH followed by NAPS and RAPS. The {sup 137}Cs and {sup 134}Cs isotopes have been taken up to the same extent from soil and transfer factors are similar to each other. But the stable Cs uptake appears to be slightly high, probably because of excess of {sup 133}Cs (mg level) added as compared to the radioactive isotopes. In spite of this high difference in the soil concentrations of Cs isotopes, uptake of {sup 133}Cs is not very high indicating to a physiological limiting process for uptake

  5. Comparison of model microbial allocation parameters in soils of varying texture

    Science.gov (United States)

    Hagerty, S. B.; Slessarev, E.; Schimel, J.

    2017-12-01

    The soil microbial community decomposes the majority of carbon (C) inputs to the soil. However, not all of this C is respired—rather, a substantial portion of the carbon processed by microbes may remain stored in the soil. The balance between C storage and respiration is controlled by microbial turnover rates and C allocation strategies. These microbial community properties may depend on soil texture, which has the potential to influence both the nature and the fate of microbial necromass and extracellular products. To evaluate the role of texture on microbial turnover and C allocation, we sampled four soils from the University of California's Hastings Reserve that varied in texture (one silt loam, two sandy loam, and on clay soil), but support similar grassland plant communities. We added 14C- glucose to the soil and measured the concentration of the label in the carbon dioxide (CO2), microbial biomass, and extractable C pools over 7 weeks. The labeled biomass turned over the slowest in the clay soil; the concentration of labeled biomass was more than 1.5 times the concentration of the other soils after 8 weeks. The clay soil also had the lowest mineralization rate of the label, and mineralization slowed after two weeks. In contrast, in the sandier soils mineralization rates were higher and did not plateau until 5 weeks into the incubation period. We fit the 14C data to a microbial allocation model and estimated microbial parameters; assimilation efficiency, exudation, and biomass specific respiration and turnover for each soil. We compare these parameters across the soil texture gradient to assess the extent to which models may need to account for variability in microbial C allocation across soils of different texture. Our results suggest that microbial C turns over more slowly in high-clay soils than in sandy soils, and that C lost from microbial biomass is retained at higher rates in high-clay soils. Accounting for these differences in microbial allocation

  6. Spatial variability in soil properties and diagnostic leaf characteristics of apple (Malus domestica) in apple growing region of Dheerkot Azad Jammu and Kashmir (AJK), Pakistan

    International Nuclear Information System (INIS)

    Arjumend, T.; Abbasi, M. K.

    2016-01-01

    Scientific information on the spatial variability in soil properties and nutrient status is important for understanding ecosystem processes and evaluating agricultural land management practices. This study aims to characterize the spatial variation of selected soil properties and the nutrient status of ten representative sites of apple growing region, and also to evaluate the nutrient contents of apple leaves of the same sites from sub-division Dheerkot, Azad Jammu and Kashmir, (AJK) Pakistan. The sampling sites were: Hill, Chamankot, Chamyati-1 (upper), Chamyati-2 (lower), Dheerkot, Kotli, Karry, Sanghar, Neelabut, and Hanschoki. The treatments included; sites = 10; depths = 04 (0-15, 15-30, 30-45, and 45-60 cm) with 3 replications. Results indicated that texture of all the sites (except one) were loam or clay loam having silt and clay the dominant soil fractions. The soils were neutral to slightly alkaline, pH ranging from 7.2 to 8.3, non-saline, and moderately calcareous (CaCO/sub 3/ 0.00-8.97 percent). The nutrient index (NI) value for soil organic matter (SOM), available P and K were 2.5, 1.5 and 2.1 showing high, medium, and medium range, respectively. The concentration of AB-DTPA extractable Fe, Mn, Cu, and Zn showed high levels of Fe (10.2-16.8 mg kg-1) and Mn (0.90-2.71 mg kg/sup -1/) while Zn (0.42-2.31 mg kg/sup -1/) deficiency was observed in few samples. All the sites were severely deficient in Cu concentration (1.35-2.05 mg kg/sup -1/). The diagnosis of apples leaves indicated that none of the samples was deficient in N (2.30-3.49 percent) and P (0.13-0.33 percent) while out of ten sites, nine sites showed severe deficiency of K (0.85-1.40 percent). The study demonstrated a significant variation in different physico-chemical properties of the soils collected from the same ecological region. In order to overcome the deficiency of some of the nutrients observed both in soil and plant samples, proper fertilization especially the use of organic manures is

  7. Water content estimated from point scale to plot scale

    Science.gov (United States)

    Akyurek, Z.; Binley, A. M.; Demir, G.; Abgarmi, B.

    2017-12-01

    Soil moisture controls the portioning of rainfall into infiltration and runoff. Here we investigate measurements of soil moisture using a range of techniques spanning different spatial scales. In order to understand soil water content in a test basin, 512 km2 in area, in the south of Turkey, a Cosmic Ray CRS200B soil moisture probe was installed at elevation of 1459 m and an ML3 ThetaProbe (CS 616) soil moisture sensor was established at 5cm depth used to get continuous soil moisture. Neutron count measurements were corrected for the changes in atmospheric pressure, atmospheric water vapour and intensity of incoming neutron flux. The calibration of the volumetric soil moisture was performed, from the laboratory analysis, the bulk density varies between 1.719 (g/cm3) -1.390 (g/cm3), and the dominant soil texture is silty clay loam and silt loamThe water content reflectometer was calibrated for soil-specific conditions and soil moisture estimates were also corrected with respect to soil temperature. In order to characterize the subsurface, soil electrical resistivity tomography was used. Wenner and Schlumberger array geometries were used with electrode spacing varied from 1m- 5 m along 40 m and 200 m profiles. From the inversions of ERT data it is apparent that within 50 m distance from the CRS200B, the soil is moderately resistive to a depth of 2m and more conductive at greater depths. At greater distances from the CRS200B, the ERT results indicate more resistive soils. In addition to the ERT surveys, ground penetrating radar surveys using a common mid-point configuration was used with 200MHz antennas. The volumetric soil moisture obtained from GPR appears to overestimate those based on TDR observations. The values obtained from CS616 (at a point scale) and CRS200B (at a mesoscale) are compared with the values obtained at a plot scale. For the field study dates (20-22.06.2017) the volumetric moisture content obtained from CS616 were 25.14%, 25.22% and 25

  8. Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables

    Science.gov (United States)

    Fox, Garey A.; Muñoz-Carpena, Rafael; Purvis, Rebecca A.

    2018-01-01

    Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3-0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with

  9. Phytotoxicity of three plant-based biodiesels, unmodified castor oil, and Diesel fuel to alfalfa (Medicago sativa L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus), and wheatgrass (Triticum aestivum).

    Science.gov (United States)

    Bamgbose, Ifeoluwa; Anderson, Todd A

    2015-12-01

    The wide use of plant-based oils and their derivatives, in particular biodiesel, have increased extensively over the past decade to help alleviate demand for petroleum products and improve the greenhouse gas emissions profile of the transportation sector. Biodiesel is regarded as a clean burning alternative fuel produced from livestock feeds and various vegetable oils. Although in theory these animal and/or plant derived fuels should have less environmental impact in soil based on their simplified composition relative to Diesel, they pose an environmental risk like Diesel at high concentrations when disposed. The aim of the present study was to ascertain the phytotoxicity of three different plant-derived biodiesels relative to conventional Diesel. For phytotoxicological analysis, we used seeds of four crop plants, Medicago sativa, Lactuca sativa, Raphanus sativus, and Triticum aestivum to analyze the germination of seeds in contaminated soil samples. The toxicological experiment was conducted with two different soil textures: sandy loam soil and silt loam soil. The studied plant-based biodiesels were safflower methyl-ester, castor methyl ester, and castor ethyl-ester. Biodiesel toxicity was more evident at high concentrations, affecting the germination and survival of small-seeded plants to a greater extent. Tolerance of plants to the biodiesels varied between plant species and soil textures. With the exception of R. sativus, all plant species were affected and exhibited some sensitivity to the fuels, such as delayed seedling emergence and slow germination (average=10 days) at high soil concentrations (0.85% for Diesel and 1.76% for the biodiesels). Tolerance of plants to soil contamination had a species-specific nature, and on average, decreased in the following order: Raphanus sativus (0-20%)>Triticum aestivum (10-40%) ≥ Medicago sativa> Lactuca sativa (80-100%). Thus, we conclude that there is some phytotoxicity associated with plant-based biodiesels. Further

  10. Soil Fertility Assessment and Mapping of Agricultural Research Station, Jaubari, Illam, Nepal

    Directory of Open Access Journals (Sweden)

    Dinesh Khadka

    2017-08-01

    Full Text Available Soil fertility evaluation is a prerequisite factor for sustainable planning of a particular region. Considering this, a study was conducted to determine the soil fertility status of the Agricultural Research Station, Jaubari, Illam, Nepal. In total, 78 soil samples were collected using soil sampling auger randomly from a depth of 0-20 cm. The texture, pH, OM, N, P2O5, K2O, Ca, Mg, S, B, Fe, Zn, Cu and Mn status of the samples were analyzed in the laboratory of Soil Science Division, Khumaltar by following standard analytical methods. The soil fertility maps of the observed parameters were prepared through Arc-GIS 10.1 software. The observed data revealed that soil was brown (10YR 4/3, dark grayish brown (10YR 4/2, dark yellowish brown (10YR 4/4 and yellowish brown (10YR 5/6 in colour, and the structure was granular. Similarly, the sand, silt and clay content were 53.84±1.06%, 34.34±0.83% and 11.82±0.47%, respectively and were indicated as sandy loam and loam in texture. The soil was very acidic (pH 3.85±0.04, and very low in available boron (0.26±0.06mg/kg and available sulphur (0.59±0.15mg/kg. The available calcium (188.7±31.30mg/kg, available magnesium (50.98±5.0mg/kg and available manganese (5.16±0.90mg/kg were low. Likewise, available potassium (110.91±7.30mg/kg, available zinc (1.19±0.31mg/kg and available copper (0.95±0.05mg/kg content were medium. Similarly, organic matter (7.88±0.32%, total nitrogen (0.27±0.01% and available phosphorus (36.53±5.66mg/kg were high, and available iron (39.5±2.17 mg/kg was very high.  International Journal of EnvironmentVolume-6, Issue-3, Jun-Aug 2017, page: 46-70

  11. The influence of reduced tillage on water regime and nutrient leaching in a loamy soil

    OpenAIRE

    Baigys, Giedrius; Gaigalis, Kazimieras; Kutra, Ginutis

    2006-01-01

    The effect of tillage technologies and terms on soil moisture regime and nitrate leaching was studied in field trials carried out on 0.76-1.36-ha fields. The study site was arranged in Pikeliai village (Kėdainiai district). The soil prevailing in the study site is Endocalcari - Endohypogleic Cambisol, sandy light loam and sandy loam on deeper layers of sandy loam and sandy light loam. The arable horizon contains sandy light loam, which is characteristic of the soils prevailing in the Middle L...

  12. Evidence for existence of different Escherichia coli populations in karst aquifer depending on hydrological conditions and the use of watershed. Fabienne Petit1*, Mehdy Ratajczak1, Nicolas Massei 1, Olivier Clermont 2, Erick Denamur 2, Thierry Berthe1,. 1CNRS UMR 6143 M2C, Université de Rouen, FED SCALE 4116, 76821 Mont Saint Aignan 2 INSERM U722, Université Paris 7 Denis Diderot ,75018 Paris

    Science.gov (United States)

    Fabienne, P.; Mehdy, R.; Massei, N.; Clermont, O.; Denamur, E.; Berthe, T.

    2011-12-01

    Escherichia coli (E. coli) is a commensal bacterium of the gastro-intestinal tract of human and vertebrate animals, even if the aquatic environment could be considered as a secondary habitat. During turbids events consecutive to the rainfall, E.coli are released from manure and feces in karstic hydrosystem with different settling velocities, related to their association to particles. In water, survival of E. coli, was dependant to the grazing by protozoans and their ability to overcome environmental stress. In these conditions, viable but non culturable (VNC) population of E. coli, could be observed. The aim of this study was to investigate, in a small well characterized rural karstic watershed (i) the structure of E. coli population based on the survival ability, the distribution in four main phylo-groups (A, B1, B2, D), and the phenotypic characteristics, (ii) the fate and the distribution of viable non culturable E. coli according their settling velocities, from surface water to groundwater. For this purpose we combined microbiology and hydrology approaches, and solid phase cytometry (ChemScan°RDI) methodology was performed to numbered VNC E. coli. The distribution in the four main E. coli phylo-groups (A, B1, B2, D) shown that the E. coli population structure was modified not only by the hydrological conditions but also the use of the watershed (presence of cattle). Survival abilities of E. coli strains based on microcosm experiments, vary from 2 days to at least 14 days. Characterization of E. coli was performed by studying specific traits present in host-associated strains (virulence factors, antibiotic resistance) and those that could be involved in water persistence (growth temperature substrate range, biofilm formation and grazing by protozoa). Three major clusters of strains were defined by using a correspondence factor analysis. In water characterized by high level of fecal contamination a first cluster of E. coli strains was related to A and B2 phylo-group, presented a multiple-antibiotic-resistance profile, and had low survival abilities in water. In slightly contaminated water, E. coli strains were persistent in water, sensitive to antibiotics, and able to develop at low temperature (from 7°C to 20°C) and to degrade macromolecules. In the same karstic hydrosystem, whatever the hydrological conditions, a population of E. coli in VNC state was observed, even in dry period where VNC E. coli raised to 96% of the total viable E. coli population. The distribution of the E. coli VNC population according to their settling velocity varies along the transfer between the swallow hole to the spring. Thus rapid flow inside karstic aquifer supports the culturability of E. coli. In contrast, in during low-flow period with slow transport of contaminant, E. coli lose their culturability but could maintained inside in VNC state in such hydrosystem.

  13. Selective nature and inherent variability of interrill erosion across prolonged rainfall simulation

    Science.gov (United States)

    Hu, Y.; Kuhn, N. J.; Fister, W.

    2012-04-01

    Sediment of interrill erosion has been generally recognized to be selectively enriched with soil organic carbon (SOC) and fine fractions (clay/silt-sized particles or aggregates) in comparison to source area soil. Limited kinetic energy and lack of concentrated runoff are the dominant factors causing selective detachment and transportation. Although enrichment ratios of SOC (ERsoc) in eroded sediment were generally reported > 1, the values varied widely. Causal factors to variation, such as initial soil properties, rainfall properties and experimental conditions, have been extensively discussed. But less attention was directed to the potential influence of prolonged rainfall time onto the temporal pattern of ERsoc. Conservation of mass dictates that ERsoc must be balanced by a decline in the source material which should also lead to a reduced or even negative ERsoc in sediment over time. Besides, the stabilizing effects of structural crust on reducing erosional variation, and the unavoidable variations of erosional response induced by the inherent complexity of interrill erosion, have scarcely been integrated. Moreover, during a prolonged rainfall event surface roughness evolves and affects the movement of eroded aggregates and mineral particles. In this study, two silt loams from Möhlin, Switzerland, organically (OS) and conventionally farmed (CS), were exposed to simulated rainfall of 30 mm h-1 for up to 6 hours. Round donut-flumes with a confined eroding area (1845 cm2) and limited transporting distance (20 cm) were used. Sediments, runoff and subsurface flow were collected in intervals of 30 min. Loose aggregates left on the eroded soil surface, crusts and the soil underneath the crusts were collected after the experiment. All the samples were analyzed for total organic carbon (TOC) content, and texture. Laser scanning of soil surface was applied before and after the rainfall event. The whole experiment was repeated for 10 times. Results from this study showed

  14. Interrelationships between soil biota and soil physical properties in forest areas of the Pieniny National Park (Poland)

    Science.gov (United States)

    Józefowska, Agnieszka; Zaleski, Tomasz; Sokołowska, Justyna; Dzierwa, Agata

    2017-04-01

    The study area was located in the Pieniny National Park (PNP) in the Carpathian Mountain (Southern Poland). Investigated soil belonged to Eutric Cambisols and had silt or silt loam texture. The purpose of this research was to investigated relationship between soil biota, such as microbial activity, soil Oligochaeta (Lumbricidae and Enchytraeidae) and soil physical properties, such as water retention or aggregates stability. This research was conducted at six forest monitoring areas of the PNP. Sampling was collected in the September 2016. For each of the 6 places, undisturbed and disturbed soil samples were taken from the 0-15-cm and 15-30-cm layer in 3 to 5 replicates. Undisturbed soil was taken: i) into Kopecky cylinders to determined soil physical properties; ii) a soil cores to determined enchytraeids and fine roots biomass (RB). Disturbed soil was collected in 3 reps and homogenized. Next such soil samples were divided into three parts: i) fresh one to determined dehydrogenase activity (ADh), microbial carbon biomass (MC) and labile carbon (LC); ii) air-dried, passed through a sieve (2-mm mesh size) and used for analysis: pH, organic carbon and bulk density; iii) last part air dried was used to determined stability of different size aggregates. In field, earthworms were collected in 3 reps using hand sorting method. Investigated soils were strongly acidic to neutral (pH 4.8-6.8). Organic carbon (Corg) content was varied from 0.8% to 4.5% and was higher in 0-15-cm layers than in 15-30-cm layers. Higher Corgcontent was connected with lower bulk density. Enchytraeids density was ranged from 1807 ind. m-2 to 88855 ind. m-2 and was correlated with microbial activity (ADh and MB) and RB. Earthworms density (ED) was ranged from 7 ind. m-2to 507 ind. m-2. In investigated soil was 6 genus and 7 species (Octolasion lacteum, Aporrectodea caliginosa, Aporrectodea rosea, Aporrectodea jassyensis, Lumbricus rubellus, Eisenia lucens, and Fitzingeria platyura depressa). ED was

  15. Introducción de cultivos de cobertura en la rotación soja-maíz: efecto sobre algunas propiedades del suelo Inclusion of cover crops in a soybean-corn rotation: effect on some soil properties

    Directory of Open Access Journals (Sweden)

    Silvina Beatriz Restovich

    2011-07-01

    Full Text Available Los suelos franco limosos de la Pampa Ondulada bajo siembra directa (SD con predominio de soja y, secundariamente maíz, registran una progresiva disminución de su fertilidad física y química. La introducción de cultivos de cobertura (CC en sistemas agrícolas cada vez menos diversificados podría constituir una herramienta agronómica para mitigar esta degradación edáfica. Los objetivos del trabajo fueron: 1 evaluar el efecto de diferentes CC sobre algunas propiedades del suelo (porosidad, distribución de tamaño de poros, estabilidad estructural, densidad aparente, carbono orgánico del suelo (COS, carbono lábil y 2 analizar la evolución de las propiedades edáficas durante la introducción de CC en la secuencia soja-maíz bajo SD. En 2005, se instaló un ensayo sobre un Argiudol típico (franco limoso con diferentes especies de ciclo otoño-invernal, utilizadas como CC. Las especies fueron: cebada forrajera (Hordeum vulgare L., ray grass (Lolium multiflorum L., avena (Avena sativa L., cebadilla (Brumus unioloides L., vicia (Vicia sativa L., colza (Brassica napus L., nabo forrajero (Raphanus sativus L., una consociación de vicia y avena y un testigo sin CC. Los cambios en las propiedades edáficas producidos durante la introducción de CC fueron: aumento de la macroporosidad y de su estabilidad y aumento del COS y de su fracción lábil. Estos cambios fueron de mediana a baja magnitud, se registraron principalmente próximos a la superficie (0-5 cm, estuvieron asociados a los momentos en los que se realizaron aportes importantes de C y fueron fáciles de revertir en asociación con períodos de lluvias intensas. El efecto acumulado de la rotación mostró mayor aporte de COS al sistema en presencia de CC. De los CC probados, se destacó el nabo forrajero como generador de porosidad y la avena como estabilizadora del sistema poroso.Silt loam soils of the Rolling Pampas cultivated with soybean and, secondarily, corn under no

  16. Mobility of the element aluminium in the weathering of hard coal material containing pyrites. Investigations on piled-up clay and silt stones of the Upper Carbon layer. Mobilitaet des Elementes Aluminium bei der Verwitterung von pyrithaltigem Steinkohlenbergematerial. Untersuchungen an aufgehaldeten Ton- und Siltsteinen des Oberkarbons

    Energy Technology Data Exchange (ETDEWEB)

    Finke, G

    1992-06-17

    In connection with the recultivation problems of mining material, investigations were made of the mobility and toxicity of aluminium in the course of weathering of mining material containing upper carbonic pyrites, and particular attention was paid to interaction of the aluminium with other ions in the weathering solution. From the aluminium type, from the ratios of Ca/Al, Al/SO[sub 4] and Al/TOC, and based on these investigations, the aluminium factor can probably be excluded as the main cause of the difficult recultivation and re-greening of mining material in the first decade of weathering. Only certain types of aluminium have toxic effects. These include ionic aluminium and different aluminium hydroxy compounds. Sulphate, fluoride, nitrate compounds of aluminium and organic aluminium compounds have not proved to be toxic. The proportion of aluminium in the ion pool can be decisive, as shown by the Ca/Al ratio. The ratio of these two cations determines the degree of danger from aluminium, depending on the type of plant. (orig.)

  17. Genotypic difference in "1"3"7Cs accumulation and transfer from the contaminated field in Fukushima to azuki bean (Vigna angularis)

    International Nuclear Information System (INIS)

    Win, Khin Thuzar; Oo, Aung Zaw; Kojima, Katsuhiro; Salem, Djedidi; Yamaya, Hiroko; Bellingrath-Kimura, Sonoko Dorothea; Tomooka, Norihiko; Kaga, Akito; Ohkama-Ohtsu, Naoko; Yokoyama, Tadashi

    2016-01-01

    The screening of mini-core collection of azuki bean accessions (Vigna angularis (Willd.) Ohwi & Ohashi) for comparative uptake of "1"3"7Cs in their edible portions was done in field trials on land contaminated by the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Ninety seven azuki bean accessions including their wild relatives from a Japanese gene bank, were grown in a field in the Fukushima prefecture, which is located approximately 51 km north of FDNPP. The contamination level of the soil was 3665 ± 480 Bq kg"−"1 dry weight ("1"3"7Cs, average ± SD). The soil type comprised clay loam, where the sand: silt: clay proportion was 42:21:37. There was a significant varietal difference in the biomass production, radiocaesium accumulation and transfer factor (TF) of radiocaesium from the soil to edible portion. Under identical agricultural practice, the extent of "1"3"7Cs accumulation by seeds differed between the accessions by as much as 10-fold. Inter-varietal variation was expressed at the ratio of the maximum to minimum observed "1"3"7Cs transfer factor for seeds ranged from 0.092 to 0.009. The total biomass, time to flowering and maturity, and seed yield had negative relationship to "1"3"7Cs activity concentration in seeds. The results suggest that certain variety/varieties of azuki bean which accumulated less "1"3"7Cs in edible portion with preferable agronomic traits are suitable to reduce the "1"3"7Cs accumulation in food chain on contaminated land. - Highlights: • Varietal difference in the biomass, "1"3"7Cs accumulation and transfer factor was found in azuki. • "1"3"7Cs accumulation by seeds differed between the azuki bean accessions by as much as 10 folds. • Different accumulation patterns among the azuki bean accessions depends on their growth performance.

  18. Runoff, sediment, nitrogen, and phosphorus losses from agricultural land converted to sweetgum and switchgrass bioenergy feedstock production in north Alabama

    Energy Technology Data Exchange (ETDEWEB)

    Nyakatawa, E.Z.; Mays, D.A. [Alabama A and M University, Normal (United States). Department of Plant and Soil Science; Tolbert, V.R. [Oak Ridge National Laboratory, Oak Ridge, TN (United States). Bionergy Feedstock Development Project; Green, T.H.; Bingham, L. [Alabama A and M University, Normal (United States). Center for Forestry and Ecology

    2006-07-15

    Renewable energy sources such as bioenergy crops have significant potential as alternatives to fossil fuels. Potential environmental problems arising from soil sediment and nutrient losses in runoff water from bioenergy crops need to be evaluated in order to determine the sustainability and overall feasibility of implementing bioenergy development strategies. This paper discusses runoff, sediment, N, and total P losses from agricultural land (continuous cotton (Gossypium hirsutum L.)) converted to short-rotation sweetgum (Liquidamber styraciflua L.) plantations with and without fescue (Festuca elatior L.) and switchgrass (Panicum virgatum L.) bioenergy crops, compared to corn (Zea mays L.), on a Decatur silt loam soil in north Alabama, from 1995 to 1999. Runoff volume was significantly correlated to total rainfall and sediment yield in each year, but treatment differences were not significant. Sweetgum plots produced the highest mean sediment yield of up to 800kgha{sup -1}compared to corn and switchgrass plots, which averaged less than 200kgha{sup -1}. Runoff NH{sub 4}{sup +} N losses averaged over treatments and years for spring season (3.1kgha{sup -1}) were three to five times those for summer, fall, and winter seasons. Runoff NO{sub 3}{sup -} N for no-till corn and switchgrass plots in spring and summer were five to ten times that for sweetgum plots. No-till corn and switchgrass treatments had 2.4 and 2.1kgha{sup -1} average runoff total P, respectively, which were two to three times that for sweetgum treatments. Growing sweetgum with a fescue cover crop provides significantly lower risk of water pollution from sediment, runoff NH{sub 4}{sup +} N, and NO{sub 3}{sup -} N. (author)

  19. Microbial populations in an agronomically managed mollisol treated with simulated acid rain

    International Nuclear Information System (INIS)

    Miller, K.W.; Cole, M.A.; Banwart, W.L.

    1991-01-01

    A fertile well-buffered mollisol (Flanagan silt loam, fine montmorillonitic mesic Aquic Arguidoll) under cultivation with corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] was subjected to simulated rain of pH 5.6, 4.2, and 3.0, while moisture-activated rain exclusion shelters provided protection from ambient rain. Soil was sampled to a depth of 3 cm on four dates throughout the 1985 growing season. The following microorganisms were enumerated by plate counts or most probable number: general heterotrophic bacteria, general soil fungi, free-living N-fixing bacteria, fluorescent pseudomonads, autotrophic ammonium-oxidizing, nitrite-oxidizing, and thio-sulfate-oxidizing bacteria. The ANOVA was used to determine the combined and individual effects of rain treatments, crop field, and sampling date. Crop field and sampling date affected microbial numbers more than rain treatments. Overall, rain treatment effects were limited to nitrite-oxidizing bacteria; lower numbers occurred in the corn field in subplots treated with rain of pH 4.2 and 3.0, and in the soybean field treated with rain of pH 3.0. The trend was strongest in June and July. In the corn field in subplots treated with rain of pH 3.0, numbers of thiosulfate-oxidizing bacteria were higher an numbers of general heterotrophic bacteria were lower; however, these trends were comparatively weak. Rain treatments caused essentially no decrease in soil pH, suggesting that acid rain constituents affect certain microbial populations without causing overt changes in pH. Because they appear to be unusually sensitive, nitrite-oxidizing bacteria could be used as experimental indicators of changes in soil microbial communities subjected to acid rain

  20. Surface barrier research at the Hanford Site

    International Nuclear Information System (INIS)

    Gee, G.W.; Ward, A.L.; Fayer, M.J.

    1997-01-01

    At the DOE Hanford Site, a field-scale prototype surface barrier was constructed in 1994 over an existing waste site as a part of a CERCLA treatability test. The above-grade barrier consists of a fine-soil layer overlying coarse layers of sands, gravels, basalt rock (riprap), and a low permeability asphalt layer. Two sideslope configurations, clean-fill gravel on a 10:1 slope and basalt riprap on a 2:1 slope, were built and are being tested. Design considerations included: constructability; drainage and water balance monitoring, wind and water erosion control and monitoring; surface revegetation and biotic intrusion; subsidence and sideslope stability, and durability of the asphalt layer. The barrier is currently in the final year of a three-year test designed to answer specific questions related to stability and long-term performance. One half of the barrier is irrigated such that the total water applied, including precipitation, is 480 mm/yr (three times the long-term annual average). Each year for the past two years, an extreme precipitation event (71 mm in 8 hr) representing a 1,000-yr return storm was applied in late March, when soil water storage was at a maximum. While the protective sideslopes have drained significant amounts of water, the soil cover (2-m of silt-loam soil overlying coarse sand and rock) has never drained. During the past year there was no measurable surface runoff or wind erosion. This is attributed to extensive revegetation of the surface. In addition, the barrier elevation has shown a small increase of 2 to 3 cm that is attributed to a combination of root proliferation and freeze/thaw activity. Testing will continue through September 1997. Performance data from the prototype barrier will be used by DOE in site-closure decisions at Hanford

  1. Mapping Ground Subsidence Phenomena in Ho Chi Minh City through the Radar Interferometry Technique Using ALOS PALSAR Data

    Directory of Open Access Journals (Sweden)

    Dinh Ho Tong Minh

    2015-07-01

    Full Text Available The rapidly developing urbanization since the last decade of the 20th century has led to extensive groundwater extraction, resulting in subsidence in Ho Chi Minh City, Vietnam. Recent advances in multi-temporal spaceborne SAR interferometry, especially with a persistent scatters interferometry (PSI approach, has made this a robust remote sensing technique for measuring large-scale ground subsidence with millimetric accuracy. This work has presented an advanced PSI analysis, to provide an unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City from 2006 to 2010. The study shows that subsidence is most severe in the Holocene silt loam areas along the Sai Gon River and in the southwest of the city. The groundwater extraction resulting from urbanization and urban growth is mainly responsible for the subsidence. Subsidence in turn leads to more flooding and water nuisance. The correlation between the reference leveling velocity and the estimated PSI result is R2 = 0.88, and the root mean square error is 4.3 (mm/year, confirming their good agreement. From 2006 to 2010, the estimation of the average subsidence rate is -8.0 mm/year, with the maximum value up to -70 mm/year. After four years, in regions along Sai Gon River and in the southwest of the city, the land has sunk up to -12 cm. If not addressed, subsidence leads to the increase of inundation, both in frequency and spatial extent. Finally, regarding climate change, the effects of subsidence should be considered as appreciably greater than those resulting from rising sea level. It is essential to consider these two factors, because the city is inhabited by more than 7.5 million people, where subsidence directly impacts urban structures and infrastructure.

  2. Effluent Storage and Biomat Occurrence among Septic System Absorption Field Architectures in a Typic Fragiudult.

    Science.gov (United States)

    Prater, N J M; Brye, K R; Dunn, S; Soerens, T S; Sharpley, A N; Mason, E; Gbur, E E

    2013-07-01

    On-site wastewater treatment systems (OWTSs) are commonly used by households in areas of low population density to treat household wastewater and recycle it back to the environment. However, new absorption field products of differing architecture types have recently become available. A 3-yr field study was conducted in Bethel Heights, northwest Arkansas to assess several newer architecture types (i.e., chambers, polystyrene-aggregate, and gravel-less pipe) relative to the traditional pipe-and-gravel design under wet- and dry-soil conditions. Thirteen products of four different architecture types were installed in 46-cm-deep trenches in a Captina silt loam (fine-silty, siliceous, active, mesic Typic Fragiudult). Products were evaluated based on in-trench solution storage measured with an electronic water-level sensor approximately weekly from January 2009 through January 2012. Between May 2010 and January 2012, the thickness of any biomat formation was measured approximately weekly by insertion of a wooden dowel through in-trench monitoring ports. Architecture type alone did not affect ( > 0.05) in-trench solution storage. However, solution storage among individual products differed under wet- and dry-soil conditions ( storage but that several alternative products also had greater solution storage than that of the traditional pipe-and-gravel system. With no observed effluent surfacing, the soil morphology approach appears to be adequate and appropriately environmentally conservative for assigning typical single-family loading rates to alternative OWTS products and to the traditional pipe-and-gravel system. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  3. Phosphorus runoff from turfgrass as affected by phosphorus fertilization and clipping management.

    Science.gov (United States)

    Bierman, Peter M; Horgan, Brian P; Rosen, Carl J; Hollman, Andrew B; Pagliari, Paulo H

    2010-01-01

    Phosphorus enrichment of surface water is a concern in many urban watersheds. A 3-yr study on a silt loam soil with 5% slope and high soil test P (27 mg kg(-1) Bray P1) was conducted to evaluate P fertilization and clipping management effects on P runoff from turfgrass (Poa pratensis L.) under frozen and nonfrozen conditions. Four fertilizer treatments were compared: (i) no fertilizer, (ii) nitrogen (N)+potassium (K)+0xP, (iii) N+K+1xP, and (iv) N+K+3xP. Phosphorus rates were 21.3 and 63.9 kg ha(-1) yr(-1) the first year and 7.1 and 21.3 kg ha(-1) yr(-1) the following 2 yr. Each fertilizer treatment was evaluated with clippings removed or clippings recycled back to the turf. In the first year, P runoff increased with increasing P rate and P losses were greater in runoff from frozen than nonfrozen soil. In year 2, total P runoff from the no fertilizer treatment was greater than from treatments receiving fertilizer. This was because reduced turf quality resulted in greater runoff depth from the no fertilizer treatment. In year 3, total P runoff from frozen soil and cumulative total P runoff increased with increasing P rate. Clipping management was not an important factor in any year, indicating that returning clippings does not significantly increase P runoff from turf. In the presence of N and K, P fertilization did not improve turf growth or quality in any year. Phosphorus runoff can be reduced by not applying P to high testing soils and avoiding fall applications when P is needed.

  4. Liming Poultry Manures to Kill Pathogens and Decrease Soluble Phosphorus

    International Nuclear Information System (INIS)

    Maguire, R.; Hesterberg, D.; Gernat, A.; Anderson, K.; Wineland, M.; Grimes, J.

    2006-01-01

    Received for publication September 9, 2005. Stabilizing phosphorus (P) in poultry waste to reduce P losses from manured soils is important to protect surface waters, while pathogens in manures are an emerging issue. This study was conducted to evaluate CaO and Ca(OH) 2 for killing manure bacterial populations (pathogens) and stabilizing P in poultry wastes and to investigate the influence on soils following amendment with the treated wastes. Layer manure and broiler litter varying in moisture content were treated with CaO and Ca(OH) 2 at rates of 2.5, 5, 10, and 15% by weight. All treated wastes were analyzed for microbial plate counts, pH, and water-soluble phosphorus (WSP), while a few selected layer manures were analyzed by phosphorus X-ray absorption near edge structure (XANES). A loamy sand and a silt loam were amended with broiler litter and layer manure treated with CaO at rates of 0, 2.5, 5, 10, and 15% and soil WSP and pH were measured at times 1, 8, and 29 d. Liming reduced bacterial populations, with greater rates of lime leading to greater reductions; for example 10% CaO applied to 20% solids broiler litter reduced the plate counts from 793 000 to 6500 mL -1 . Liming also reduced the WSP in the manures by over 90% in all cases where at least 10% CaO was added. Liming the manures also reduced WSP in soils immediately following application and raised soil pH. The liming process used successfully reduced plate counts and concerns about P losses in runoff following land application of these limed products due to decreased WSP

  5. Non-target impact of fungicide tetraconazole on microbial communities in soils with different agricultural management.

    Science.gov (United States)

    Sułowicz, Sławomir; Cycoń, Mariusz; Piotrowska-Seget, Zofia

    2016-08-01

    Effect of the fungicide tetraconazole on microbial community in silt loam soils from orchard with long history of triazole application and from grassland with no known history of fungicide usage was investigated. Triazole tetraconazole that had never been used on these soils before was applied at the field rate and at tenfold the FR. Response of microbial communities to tetraconazole was investigated during 28-day laboratory experiment by determination of changes in their biomass and structure (phospholipid fatty acids method-PLFA), activity (fluorescein diacetate hydrolysis-FDA) as well as changes in genetic (DGGE) and functional (Biolog) diversity. Obtained results indicated that the response of soil microorganisms to tetraconazole depended on the management of the soils. DGGE patterns revealed that both dosages of fungicide affected the structure of bacterial community and the impact on genetic diversity and richness was more prominent in orchard soil. Values of stress indices-the saturated/monounsaturated PLFAs ratio and the cyclo/monounsaturated precursors ratio, were almost twice as high and the Gram-negative/Gram-positive ratio was significantly lower in the orchard soil compared with the grassland soil. Results of principal component analysis of PLFA and Biolog profiles revealed significant impact of tetraconazole in orchard soil on day 28, whereas changes in these profiles obtained for grassland soil were insignificant or transient. Obtained results indicated that orchards soil seems to be more vulnerable to tetraconazole application compared to grassland soil. History of pesticide application and agricultural management should be taken into account in assessing of environmental impact of studied pesticides.

  6. Effect of nitrogen fertilization and residue management practices on ammonia emissions from subtropical sugarcane production

    Science.gov (United States)

    mudi, Sanku Datta; Wang, Jim J.; Dodla, Syam Kumar; Arceneaux, Allen; Viator, H. P.

    2016-08-01

    Ammonia (NH3) emission from soil is a loss of nitrogen (N) nutrient for plant production as well as an issue of air quality, due to the fact that it is an active precursor of airborne particulate matters. Ammonia also acts as a secondary source of nitrous oxide (N2O) emission when present in the soil. In this study, the impacts of different sources of N fertilizers and harvest residue management schemes on NH3 emissions from sugarcane production were evaluated based on an active chamber method. The field experiment plots consisting of two sources of N fertilizer (urea and urea ammonium nitrate (UAN)) and two common residue management practices, namely residue retained (RR) and residue burned (RB), were established on a Commerce silt loam. The NH3 volatilized following N fertilizer application was collected in an impinger containing diluted citric acid and was subsequently analyzed using ion chromatography. The NH3 loss was primarily found within 3-4 weeks after N application. Average seasonal soil NH3 flux was significantly greater in urea plots with NH3-N emission factor (EF) twice or more than in UAN plots (2.4-5.6% vs. 1.2-1.7%). The RR residue management scheme had much higher NH3 volatilization than the RB treatment regardless of N fertilizer sources, corresponding to generally higher soil moisture levels in the former. Ammonia-N emissions in N fertilizer-treated sugarcane fields increased with increasing soil water-filled pore space (WFPS) up to 45-55% observed in the field. Both N fertilizer sources and residue management approaches significantly affected NH3 emissions.

  7. Plant growth and trace-element uptake on acidic coal refuse amended with lime or fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Jastrow, J.D. (Argonne National Lab., IL); Zimmerman, C.A.; Dvorak, A.J.; Hinchman, R.R.

    1981-04-01

    Two commonly used revegetation species, Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and Lincoln smooth brome (Bromus inermis Leyss.), were grown for 60 days in pots containing coarse coal mine refuse (referred to as gob, pH = 3.5) amended with either lime or alkaline powerplant fly ash. Both species were also grown in pots containing a silt loam surface soil as a control. Morphological growth parameters were measured over time; dry weights and shoot/root ratios were determined at harvest. Concentrations of Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn in the plant shoots were determined by atomic absorption spectrophotometry. Plant growth of both species was not as good on either lime- or fly ash-amended gob as it was on surface soil; however, more vigorous growth occurred on lime-amended gob than on fly ash-amended gob. Significant differences (rho < 0.05) in the tissue concentrations of Cd, Co, Fe, Hg, Mn, Pb, V, and Zn were found among the plants grown on the three substrates. Except for Hg and Pb, these elements were higher in plants grown on at least one of the amended-gob substrates than in plants grown on surface soil. Significant substrate differences were not observed for Al, As, Cr, Cu, Ni, and Se. The tissue concentrations of some elements - notably Al, Cu, Fe, Mn, V, and Zn - were high enough in plants from one or more of the substrates to either approach or exceed concentrations which have been reported to be associated with toxic effects in some plant species.

  8. Effect of two different plant growth regulators on production traits of sunflower

    Directory of Open Access Journals (Sweden)

    Dávid ERNST

    2016-12-01

    Full Text Available The plant growth regulators (PGR are an organic compounds that modify plant physiological processes. PGR applied to the field crops promotes photosynthesis, stimulates plant growth, improves flowering and protects plants against unfavourable year weather conditions. Listed is an assumption to the yield of high quality. The effects of year weather conditions, biological material (hybrids and foliar application of two different PGR (Terra-Sorb® Foliar – containing free amino acids and Unicum® – containing Abiestins® on the yield-forming parameters, seed yield and the oil content in seeds of three selected hybrids of sunflower (NK Brio, NK Neoma, NK Ferti were studied in this paper. The field poly-factorial experiments were realized during two growing seasons of 2012 and 2013. The experimental area is situated in the maize-growing region (climatic region: warm; climatic sub-region: mild dry or dry; climatic zone: warm and dry, with mild winter and long sunshine and soil is silt loam Haplic Luvisol. The climatic conditions in chosen experimental years were different in quantities and distribution of precipitation at main growth period of sunflower plants (June to August and allows evaluating the yield stability between used hybrids and foliar treatments. The results showed that the application of selected PGR has contributed to an increase of sunflower seed yield, mainly through increase the weight of thousand seeds (rp = 0.761; P < 0.001. Similarly, oil content in seeds was significantly higher in treatments with PGR, especially with preparation Terra-Sorb® Foliar containing free amino acids. The study describes the relationship between quality (oil content in seeds and quantity (seed yield of sunflower production (rp = ‒0.41; P < 0.01. Results showed that PGR can be an important rationalization tool of the sunflower cultivation technology.

  9. Agronomic-productive characteristics of two genotype of stevia rebaudiana in Central Italy

    Directory of Open Access Journals (Sweden)

    Lucia Ceccarini

    2006-06-01

    Full Text Available Stevia rebaudiana Bertoni produces a variety of high-potency low calorie sweeteners in its’ leaf tissue. The aim of this work was to evaluate the productive potential of two different Stevia rebaudiana genotypes and the characteristics of the production of the plant obtained through different cultivation methods, in central Italy. For several years (1992-2000 agronomic trials on Stevia rebaudiana cultivated in the littoral area near Pisa (Italy carried out. In 1992 two different genotypes of Stevia (B1 and B2 transplanted in silt-loam soil; in 1996 other plants from B2 genotype, produced by vegetative process (micropropagation, were transplanted in the same field. In the period from 1992-1999 the production of leaves from both genotypes increase as of the third year and the ratio leaf-aerial plant, after the peak in the third year, tends to diminish. Except the first year (1997 there were not recorded statistically significant differences between the two propagation methods employed in relation to leaf production. The quantity of leaves produced from a single harvest was less than resulting from two cuttings and the micropropagation plants produced a larger amount of leaves than those from cutting. The leaf-stem ratio was to become an interesting morphological and production characteristic parameter of the plant. Stevia rebaudiana appears particularly suited for the cultivation environment of central Italy. A particular positive aspect that must be considered in these regions is that Stevia can be grown successfully as poliannual species because crop survival over the winter is high. The results obtained show that this species is economically profitable until the 5th or 6th year of cultivation. At our latitudes is also necessary to establish a program of genetic improvement in order to develop earlier varieties that can guaranty an optimum qualitative and quantitative seed production.

  10. Analysis of Mars Analogue Soil Samples Using Solid-Phase Microextraction, Organic Solvent Extraction and Gas Chromatography/Mass Spectrometry

    Science.gov (United States)

    Orzechowska, G. E.; Kidd, R. D.; Foing, B. H.; Kanik, I.; Stoker, C.; Ehrenfreund, P.

    2011-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are robust and abundant molecules in extraterrestrial environments. They are found ubiquitously in the interstellar medium and have been identified in extracts of meteorites collected on Earth. PAHs are important target molecules for planetary exploration missions that investigate the organic inventory of planets, moons and small bodies. This study is part of an interdisciplinary preparation phase to search for organic molecules and life on Mars. We have investigated PAH compounds in desert soils to determine their composition, distribution and stability. Soil samples (Mars analogue soils) were collected at desert areas of Utah in the vicinity of the Mars Desert Research Station (MDRS), in the Arequipa region in Peru and from the Jutland region of Denmark. The aim of this study was to optimize the solid-phase microextraction (SPME) method for fast screening and determination of PAHs in soil samples. This method minimizes sample handling and preserves the chemical integrity of the sample. Complementary liquid extraction was used to obtain information on five- and six-ring PAH compounds. The measured concentrations of PAHs are, in general, very low, ranging from 1 to 60 ng g(sup -1). The texture of soils is mostly sandy loam with few samples being 100% silt. Collected soils are moderately basic with pH values of 8-9 except for the Salten Skov soil, which is slightly acidic. Although the diverse and variable microbial populations of the samples at the sample sites might have affected the levels and variety of PAHs detected, SPME appears to be a rapid, viable field sampling technique with implications for use on planetary missions.

  11. [Effect of carbon substrate concentration on N2, N2O, NO, CO2, and CH4 emissions from a paddy soil in anaerobic condition].

    Science.gov (United States)

    Chen, Nuo; Liao, Ting-ting; Wang, Rui; Zheng, Xun-hua; Hu, Rong-gui; Butterbach-Bahl, Klaus

    2014-09-01

    Understanding the effects of carbon and nitrogen substrates concentrations on the emissions of denitrification gases including nitrogen (N2) , nitrous oxide (N2O) and nitric oxide (NO), carbon dioxide (CO2) and methane (CH4) from anaerobic paddy soils is believed to be helpful for development of greenhouse gas mitigation strategies. Moreover, understanding the quantitative dependence of denitrification products compositions on carbon substrate concentration could provide some key parameters or parameterization scheme for developing process-oriented model(s) of nitrogen transformation. Using a silt loam soil collected from a paddy field, we investigated the influence of carbon substrate concentration on the emissions of the denitrification gases, CO2 and CH4 from anaerobically incubated soils by setting two treatments: control (CK) with initial soil nitrate and dissolved organic carbon (DOC) concentrations of ~ 50 mg.kg-1 and -28 mg kg-1 , respectively; and DOC added (C + ) with initial soil nitrate and DOC concentrations of ~50 mg.kg-1 and ~300 mg.kg-1 , respectively. The emissions of denitrification gases, CO2 and CH4, as well as concentrations of carbon and nitrogen substrates for each treatment were dynamically measured, using the gas-flow-soil-core technique and a paralleling substrate monitoring system. The results showed that CH4 emission was not observed in CK treatment while observed in C treatment. Aggregate emission of greenhouse gases for C + treatment was significantly higher comparing with the CK treatment (P emissions in total nitrogen gases emissions were approximately 9% , 35% and 56% for CK treatment, respectively; and approximately 31% , 50% and 19% for C+ treatment, respectively, with significant differences between these two treatments (P carbon substrate concentrations can significantly change the composition of nitrogen gas emissions. The results also implicated that organic fertilizer should not be applied to nitrate-rich paddy soils prior to

  12. Effects of long-term poultry litter application on phosphorus soil chemistry and runoff water quality.

    Science.gov (United States)

    Reiter, Mark S; Daniel, Tommy C; DeLaune, Paul B; Sharpley, Andrew N; Lory, John A

    2013-11-01

    Continuous application of poultry litter (PL) significantly changes many soil properties, including soil test P (STP); Al, Fe, and Ca concentrations; and pH, which can affect the potential for P transport in surface runoff water. We conducted rainfall simulations on three historically acidic silt loam soils in Arkansas, Missouri, and Virginia to establish if long-term PL applications would affect soil inorganic P fractions and the resulting dissolved reactive P (DRP) in runoff water. Soil samples (0-5 cm depth) were taken to find sites ranging in Mehlich-3 STP from 20 to 1154 mg P kg. Simulated rainfall events were conducted on 3-m plots at 6.7 cm h, and runoff was collected for 30 min. Correlation between Mehlich-3 and runoff DRP indicated a linear relationship to 833 mg Mehlich-3 P kg. As Mehlich-3 STP increased, a concomitant increase in soil pH and Ca occurred on all soils. Soil P fractionation demonstrated that, as Mehlich-3 STP generally increased above 450 mg P kg (from high to very high), the easily soluble and loosely bound P fractions decreased by 3 to 10%. Water-insoluble complexes of P bound to Al and Ca were the main drivers in the reduction of DRP in runoff, accounting for up to 43 and 38% of total P, respectively. Basing runoff DRP concentration projections solely on Mehlich-3 STP may overestimate runoff P losses from soils receiving long-term PL applications due to dissolution of water-insoluble Ca-P compounds. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  13. Spatial variability of atrazine dissipation in an allophanic soil.

    Science.gov (United States)

    Müller, Karin; Smith, Roger E; James, Trevor K; Holland, Patrick T; Rahman, Anis

    2003-08-01

    The small-scale variability (0.5 m) of atrazine (6-chloro-N2-ethyl-N4-isopropyl-1,3,5-triazine-2,4-diamine) concentrations and soil water contents in a volcanic silt loam soil (Haplic Andosol, FAO system) was studied in an area of 0.1 ha. Descriptive and spatial statistics were used to analyse the data. On average we recovered 102% of the applied atrazine 2 h after the herbicide application (CV = 35%). An increase in the CV of the concentrations with depth could be ascribed to a combination of extrinsic and intrinsic factors. Both variables, atrazine concentrations and soil water content, showed a high horizontal variability. The semivariograms of the atrazine concentrations exhibited the pure nugget effect, no pattern could be determined along the 15.5-m long transects on any of the seven sampling days over a 55-day period. Soil water content had a weak spatial autocorrelation with a range of 6-10 m. The dissipation of atrazine analysed using a high vertical sampling resolution of 0.02 m to 0.2 m showed that 70% of the applied atrazine persisted in the upper 0.02-m layer of the soil for 12 days. After 55 days and 410 mm of rainfall the centre of the pesticide mass was still at a soil depth of 0.021 m. The special characteristics of the soil (high organic carbon content, allophanic clay) had a strong influence on atrazine sorption and mobility. The mass recovery after 55 days was low. The laboratory degradation rate for atrazine, determined in a complementary incubation study and corrected for the actual field temperature using the Arrhenius equation, only accounted for about 35% of the losses that occurred in the field. Results suggest field degradation rates to be more changeable in time and much faster than under controlled conditions. Preferential flow is discussed as a component of the field transport process.

  14. Initial Effects of Differently Treated Biogas Residues from Municipal and Industrial Wastes on Spring Barley Yield Formation

    Science.gov (United States)

    Prays, Nadia; Kaupenjohann, Martin

    2016-01-01

    Soil application of biogas residues (BGRs) is important for closing nutrient cycles. This study examined the efficiency and impact on yields and yield formation of solid-liquid separated residues from biodegradable municipal and industrial wastes (bio-waste) in comparison to complete BGRs, nitrification inhibitor, agricultural BGRs, mineral fertilizer and unfertilized plots as control. The experiment was set up as a randomized block design on silt loam Cambisol. Biogas residues from four biogas plants were evaluated. Plants per m², ears per plant, grains per ear and thousand grain weight (TGW) were measured at harvest. Fertilization with BGRs resulted in similar biomass yields compared with mineral fertilizer. Mineral fertilizer (71 dt/ha) and plots fertilized with liquid fraction (59–62 dt/ha) indicated a trend to higher yields than solid fraction or complete BGR due to its high ammonia content. Liquid fractions and fraction with nitrification inhibitor induced fewer plants per m² than corresponding solid and complete variants due to a potential phytotoxicity of high NH4-N concentration during germination. However, barley on plots fertilized with liquid fraction compensated the disadvantages at the beginning during the vegetation period and induced higher grain yields than solid fraction. This was attributable to a higher number of ears per plant and grains per ear. In conclusion, BGRs from biodegradable municipal and industrial wastes can be used for soil fertilization and replace considerable amounts of mineral fertilizer. Our study showed that direct application of the liquid fraction of BGR is the most suitable strategy to achieve highest grain yields. Nevertheless potential phytotoxicity of the high NH4-N concentration in the liquid fraction should be considered. PMID:27116355

  15. Broiler diet modification and litter storage: impacts on phosphorus in litters, soils, and runoff.

    Science.gov (United States)

    McGrath, Joshua M; Sims, J Thomas; Maguire, Rory O; Saylor, William W; Angel, C Roselina; Turner, Benjamin L

    2005-01-01

    Modifying broiler diets to mitigate water quality concerns linked to excess phosphorus (P) in regions of intensive broiler production has recently increased. Our goals were to evaluate the effects of dietary modification, using phytase and reduced non-phytate phosphorus (NPP) supplementation, on P speciation in broiler litters, changes in litter P forms during long-term storage, and subsequent impacts of diets on P in runoff from litter-amended soils. Four diets containing two levels of NPP with and without phytase were fed to broilers in a three-flock floor pen study. After removal of the third flock, litters were stored for 440 d at their initial moisture content (MC; 24%) and at a MC of 40%. Litter P fractions and orthophosphate and phytate P concentrations were determined before and after storage. After storage, litters were incorporated with a sandy and silt loam and simulated rainfall was applied. Phytase and reduced dietary NPP significantly reduced litter total P. Reducing dietary NPP decreased water-extractable inorganic phosphorus (IP) and the addition of dietary phytase reduced NaOH- and HCl-extractable organic P in litter, which correlated well with orthophosphate and phytic acid measured by 31P nuclear magnetic resonance (NMR), respectively. Although dry storage caused little change in P speciation, wet storage increased concentrations of water-soluble IP, which increased reactive P in runoff from litter-amended soils. Therefore, diet modification with phytase and reduced NPP could be effective in reducing P additions on a watershed scale. Moreover, efforts to minimize litter MC during storage may reduce the potential for dissolved P losses in runoff.

  16. Measuring soil organic matter turn over and carbon stabilisation in pasture soils using 13C enrichment methodology.

    Science.gov (United States)

    Robinson, J. M.; Barker, S.; Schipper, L. A.

    2017-12-01

    Carbon storage in soil is a balance between photosynthesis and respiration, however, not all C compounds decompose equally in soil. Soil C consists of several fractions of C ranging from, accessible C (rapidly cycling) to stored or protected C (slow cycling). The key to increasing C storage is through the transfer of soil C from this accessible fraction, where it can be easily lost through microbial degradation, into the more stable fraction. With the increasing use of isotope enrichment techniques, 13C may be used to trace the movement of newly incorporated carbon in soil and examine how land management practises affect carbon storage. A laboratory method was developed to rapidly analyse soil respired CO2 for δ13C to determine the temperature sensitivity of newly incorporated 13C enriched carbon. A Horotiu silt loam (2 mm sieved, 60% MWHC) was mixed with 13C enriched ryegrass/clover plant matter in Hungate tubes and incubated for 5 hours at 20 temperatures( 4 - 50 °C) using a temperature gradient method (Robinson J. M., et al, (2017) Biogeochemistry, 13, 101-112). The respired CO2 was analysed using a modified Los Gatos, Off-axis ICOS carbon dioxide analyser. This method was able to analyse the δ13C signature of respired CO2 as long as a minimum concentration of CO2 was produced per tube. Further analysis used a two-component mixing model to separate the CO2 into source components to determine the contribution of added C and soil to total respiration. Preliminary data showed the decomposition of the two sources of C were both temperature dependant. Overall this method is a relatively quick and easy way to analyse δ13C of respired soil CO2 samples, and will allow for the testing of the effects of multiple variables on the decomposition of carbon fractions in future use.

  17. Comparison of ammonium sulfate and urea as nitrogen sources in rice production

    International Nuclear Information System (INIS)

    Bufogle, A. Jr.; Bollich, P.K.; Kovar, J.L.; Lindau, C.W.; Macchiavellid, R.E.

    1998-01-01

    Wetland rice agriculture is the major anthropogenic source of methane, an important greenhouse gas. Methane emissions are less when ammonium sulfate (AS) rather than urea is the nitrogen (N) source. However, an agronomic advantage of AS over urea has not been established. The objectives of this study were: (i) to compare the effectiveness of AS, urea, and urea plus elemental sulfur (S) as sources of N in flooded rice culture, (ii) to compare fertilizer recovery of each source of N from application at preflood (PF) and panicle initiation (PI), and (iii) to determine if there is a response to S by rice grown on a soil with a less than optimum level of available S. 'Cypress' rice was drill-seeded in a Crowley silt loam soil (fine, montmorillonitic, thermic Typic Albaqualf) of 7.25 to 10.75 mg S kg-1. Ammonium sulfate, urea, or urea plus S was applied in split applications of 101 kg N ha-1 PF and 50 kg N ha-1 PI. Microplots with retainers and 15N-labeled N were used. Unlabeled N was used in field plots. Microplots were harvested at 50% heading, while field plots were harvested at maturity. Dry matter and total N accumulation at 50% heading and at maturity were similar regardless of N source. Grain dry matter yields were 8.54, 8.47, and 8.79 Mg ha-1 for AS, urea, and urea plus S treatments, respectively. Greater N recovery was generally found from N application at PI than at PF, but this was not reflected by an increase in grain yield. No response to S was detected, although grain yields were slightly higher when S-containing fertilizers were used. Ammonium sulfate and urea were equally effective for flooded rice production in Louisiana

  18. A semianalytical model to predict recovery of light, nonaqueous phase liquids from unconfined aquifers

    International Nuclear Information System (INIS)

    Waddill, D.W.

    1997-01-01

    This paper describes the development and testing of a semianalytical model that may be used to design LNAPL containment and recovery systems at spill sites. The objective of this study was to derive an enhanced semianalytical algorithm for calculating recovery and trapping of free phase oil. The enhancements were derived and evaluated by comparison with an established numerical model that describes transient flow of oil and water. The semianalytical model employs an analytical solution for steady-state drawdown in an unconfined aquifer due to water pumping. When pumping rates are sufficient to contain the separate phase plume, the model calculates recoverable and residual oil volumes based on the initial free oil distribution. Refinements were implemented to calculate the water-table drawdown and the maximum unsaturated zone residual saturation (S og ) as functions of soil type. Also the influence of hysteresis on the oil-water capillary fringe was incorporated into the calculation of oil trapping below a rising oil-water interface. A method was derived to reduce saturated zone trapping to account for oil recovery that occurs while pumping proceeds. The above enhancements yielded close agreement between the semianalytical model and the transient model predictions of recoverable oil and residua oil in the unsaturated and saturated zones. The models were compared for hypothetical gasoline spills in a sandy and a silt loam soil, using a range of pumping rates and regional water-table fluctuations. Field data from a pipeline leak were evaluated by the semianalytical model for hypothetical scenarios involving oil recovery from three wells and a falling regional water table

  19. Management of Lignite Fly Ash for Improving Soil Fertility and Crop Productivity

    Science.gov (United States)

    Ram, Lal C.; Srivastava, Nishant K.; Jha, Sangeet K.; Sinha, Awadhesh K.; Masto, Reginald E.; Selvi, Vetrivel A.

    2007-09-01

    Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients, has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid, and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with and without press mud), yield increased significantly (7.0-89.0%) in relation to the control crop. The press mud enhanced the yield (3.0-15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications, the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits, was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner.

  20. Organic Biochar Based Fertilization

    Science.gov (United States)

    Schmidt, Hans-Peter; Pandit, Bishnu Hari; Cornelissen, Gerard; Kammann, Claudia

    2017-04-01

    Biochar produced in cost-efficient flame curtain kilns (Kon-Tiki) was nutrient enriched either with cow urine or with dissolved mineral (NPK) fertilizer to produce biochar-based fertilizers containing between 60-100 kg N, 5-60 kg P2O5 and 60-100 kg K2O, respectively, per ton of biochar. In 21 field trials nutrient-enriched biochars were applied at rates of 0.5 to 2 t ha-1 into the root zone of 13 different annual and perennial crops. Treatments combining biochar, compost and organic or chemical fertilizer were evaluated; control treatments contained the same amounts of nutrients but without biochar. All nutrient-enriched biochar substrates improved yields compared to their respective no-biochar controls. Biochar enriched with dissolved NPK produced on average 20% ± 5.1% (N=4) higher yields than standard NPK fertilization without biochar. Cow urine-enriched biochar blended with compost resulted on average in 123% ± 76.7% (N=13) higher yields compared to the organic farmer practice with cow urine-blended compost and outcompeted NPK-enriched biochar (same nutrient dose) by 103% ± 12.4% (N=4) on average. 21 field trials robustly revealed that low-dosage root zone application of organic biochar-based fertilizers caused substantial yield increases in rather fertile silt loam soils compared to traditional organic fertilization and to mineral NPK- or NPK-biochar fertilization. This can likely be explained by the nutrient carrier effect of biochar causing a slow nutrient release behavior, more balanced nutrient fluxes and reduced nutrient losses especially when liquid organic nutrients are used for the biochar enrichment. The results promise new pathways for optimizing organic farming and improving on-farm nutrient cycling.

  1. Carbon dioxide efflux from soil with poultry litter applications in conventional and conservation tillage systems in northern Alabama.

    Science.gov (United States)

    Roberson, T; Reddy, K C; Reddy, S S; Nyakatawa, E Z; Raper, R L; Reeves, D W; Lemunyon, J

    2008-01-01

    Increased CO2 release from soils resulting from agricultural practices such as tillage has generated concerns about contributions to global warming. Maintaining current levels of soil C and/or sequestering additional C in soils are important mechanisms to reduce CO2 in the atmosphere through production agriculture. We conducted a study in northern Alabama from 2003 to 2006 to measure CO2 efflux and C storage in long-term tilled and non-tilled cotton (Gossypium hirsutum L.) plots receiving poultry litter or ammonium nitrate (AN). Treatments were established in 1996 on a Decatur silt loam (clayey, kaolinitic thermic, Typic Paleudults) and consisted of conventional-tillage (CT), mulch-tillage (MT), and no-tillage (NT) systems with winter rye [Secale cereale (L.)] cover cropping and AN and poultry litter (PL) as nitrogen sources. Cotton was planted in 2003, 2004, and 2006. Corn was planted in 2005 as a rotation crop using a no-till planter in all plots, and no fertilizer was applied. Poultry litter application resulted in higher CO2 emission from soil compared with AN application regardless of tillage system. In 2003 and 2006, CT (4.39 and 3.40 micromol m(-2) s(-1), respectively) and MT (4.17 and 3.39 micromol m(-2) s(-1), respectively) with PL at 100 kg N ha(-1) (100 PLN) recorded significantly higher CO2 efflux compared with NT with 100 PLN (2.84 and 2.47 micromol m(-2) s(-1), respectively). Total soil C at 0- to 15-cm depth was not affected by tillage but significantly increased with PL application and winter rye cover cropping. In general, cotton produced with NT conservation tillage in conjunction with PL and winter rye cover cropping reduced CO2 emissions and sequestered more soil C compared with control treatments.

  2. Interactions of tillage and cover crop on water, sediment, and pre-emergence herbicide loss in glyphosate-resistant cotton: implications for the control of glyphosate-resistant weed biotypes.

    Science.gov (United States)

    Krutz, L Jason; Locke, Martin A; Steinriede, R Wade

    2009-01-01

    The need to control glyphosate [N-(phosphonomethyl)glycine]-resistant weed biotypes with tillage and preemergence herbicides in glyphosate-resistant crops (GRCs) is causing a reduction in no-tillage hectarage thereby threatening the advances made in water quality over the past decade. Consequently, if environmental gains afforded by GRCs are to be maintained, then an in-field best management practice (BMP) compatible with tillage is required for hectarage infested with glyphosate-resistant weed biotypes. Thus, 1 d after a preemergent application of fluometuron [N,N-dimethyl-N'-(3-(trifluoromethyl)phenyl)urea] (1.02 kg ha(-1)) and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] (1.18 kg ha(-1)) to a Dundee silt loam (fine-silty, mixed, active, thermic Typic Endoaqualf), simulated rainfall (60 mm h(-1)) was applied to 0.0002-ha microplots for approximately 1.25 h to elucidate tillage (no tillage [NT] and reduced tillage [RT])and cover crop (no cover [NC] and rye cover [RC]) effects on water, sediment, and herbicide loss in surface runoff. Regardless of tillage, RC delayed time-to-runoff 1.3-fold, reduced cumulative runoff volume 1.4-fold, and decreased cumulative sediment loss 4.7-fold. Cumulative fluometuron loss was not affected by tillage or cover crop. Conversely, total metolachlor loss was 1.3-fold lower in NT than RT and 1.4-fold lower in RC than NC. These data indicate that RC can be established in hectarage requiring tillage and potentially curtail water, sediment, and preemergence herbicide losses in the spring to levels equivalent to or better than that of NT, thereby protecting environmental gains provided by GRCs.

  3. Field Lysimeter Test Facility status report IV: FY 1993

    International Nuclear Information System (INIS)

    Gee, G.W.; Felmy, D.G.; Ritter, J.C.; Campbell, M.D.; Downs, J.L.; Fayer, M.J.; Kirkham, R.R.; Link, S.O.

    1993-10-01

    At the U.S. Department of Energy's Hanford Site near Richland, Washington, a unique facility, the Field Lysimeter Test Facility (FLTF) is used to measure drainage from and water storage in soil covers. Drainage has ranged from near zero amounts to more than 50% of the applied water, with the amount depending on vegetative cover and soil type. Drainage occurred from lysimeters with coarse soils and gravel covers, but did not occur from capillary barrier-type lysimeters (1.5 m silt loam soil over coarse sands and gravels) except under the most extreme condition tested. For capillary barriers that were irrigated and kept vegetation-free (bare surface), no drainage occurred in 5 of the past 6 years. However, this past year (1992--1993) a record snowfall of 1,425 mm occurred and water storage in the irrigated, bare-surfaced capillary barriers exceeded 500 mm resulting in drainage of more than 30 mm from these barriers. In contrast, capillary barriers, covered with native vegetation (i.e., shrubs and grasses) did not drain under any climatic condition (with or without irrigation). In FY 1994, the FLTF treatments will be increased from 11 to 17 with the addition of materials that will simulate portions of a prototype barrier planned for construction in 1994 at the Hanford Site. The 17 FLTF treatments are designed to test the expected range of surface soil, vegetation, and climatic conditions encountered at the Hanford Site and will assist in evaluating final surface barrier designs for a waste disposal facility

  4. Potassium-phosphorus relationships in cotton (gossypium hirsutum L.) as affected by potassium nutrition

    International Nuclear Information System (INIS)

    Makhdum, M.I.; Ashraf, M.

    2007-01-01

    Field studies were undertaken to determine the interrelationship between potassium (K+) concentration in various organs of plant and phosphorus (P) content as influenced by K-nutrition in cotton. The experiment was conducted on Miani soil series silt loam and classified as Calcaric Cambisols, fine silty, mixed Hyperthermic Fluventic Haplocambids. The treatments consisted .of (a) four cotton (Gossypium hirsutum L.) cultivars (CI.M-448, CIM-IIOO, Karishma, S-12); and (b) four potassium fertilizer doses (0, 62.5, 125.0, 250.0 kg K ha-l). The design of experiment was split plot (main: cultivars, sub-plot: K-doses). The plant samples were collected at five stages of growth, i.e., first flower bud., first flower, peak flowering, first boll split and maturity. The various parts of plants were analyzed for phosphorus and potassium concentration at various stages of growth. Phosphorus concentration in leaves, stems, burs, seed and lint decreased with concurrent increase in K-doses. Crop maintained 0.22% phosphorus concentration in leaf tissues at first flower bud and dropped to 0.11% at maturity. Cultivars differed greatly amongst themselves in terms of maintaining P content in their different parts. Averaged across K-doses, cv. CIM-448 maintained the highest P content in all parts than other cultivars. There was a negative and significant correlation co-efficient between K and P concentration in various parts of the plant. The study demonstrated antagonistic interaction between K+ and P in cotton plant under irrigated conditions. (author)

  5. Cyanobacteria Inoculation Improves Soil Stability and Fertility on Different Textured Soils: Gaining Insights for Applicability in Soil Restoration

    Directory of Open Access Journals (Sweden)

    Sonia Chamizo

    2018-06-01

    Full Text Available Cyanobacteria are ubiquitous components of biocrust communities and the first colonizers of terrestrial ecosystems. They play multiple roles in the soil by fixing C and N and synthesizing exopolysaccharides, which increase soil fertility and water retention and improve soil structure and stability. Application of cyanobacteria as inoculants to promote biocrust development has been proposed as a novel biotechnological technique for restoring barren degraded areas and combating desertification processes in arid lands. However, previous to their widespread application under field conditions, research is needed to ensure the selection of the most suitable species. In this study, we inoculated two cyanobacterial species, Phormidium ambiguum (non N-fixing and Scytonema javanicum (N-fixing, on different textured soils (from silt loam to sandy, and analyzed cyanobacteria biocrust development and evolution of physicochemical soil properties for 3 months under laboratory conditions. Cyanobacteria inoculation led to biocrust formation in all soil types. Scanning electron microscope (SEM images showed contrasting structure of the biocrust induced by the two cyanobacteria. The one from P. ambiguum was characterized by thin filaments that enveloped soil particles and created a dense, entangled network, while the one from S. javanicum consisted of thicker filaments that grouped as bunches in between soil particles. Biocrust development, assessed by chlorophyll a content and crust spectral properties, was higher in S. javanicum-inoculated soils compared to P. ambiguum-inoculated soils. Either cyanobacteria inoculation did not increase soil hydrophobicity. S. javanicum promoted a higher increase in total organic C and total N content, while P. ambiguum was more effective in increasing total exopolysaccharide (EPS content and soil penetration resistance. The effects of cyanobacteria inoculation also differed among soil types and the highest improvement in soil

  6. Feasibility of biochar manufactured from organic wastes on the stabilization of heavy metals in a metal smelter contaminated soil.

    Science.gov (United States)

    Abdelhafez, Ahmed A; Li, Jianhua; Abbas, Mohamed H H

    2014-12-01

    The main objectives of the current study were to evaluate the potential effects of biochar derived from sugar cane bagasse (SC-BC) and orange peel (OP-BC) on improving the physicochemical properties of a metal smelter contaminated soil, and determining its potentiality for stabilizing Pb and As in soil. To achieve these goals, biochar was produced in a small-scale biochar producing plant, and an incubation experiment was conducted using a silt loam metal-contaminated soil treated with different application rates of biochar (0-10% w/w). The obtained results showed that, the addition of SC-BC and OP-BC increased significantly the soil aggregate stability, water-holding capacity, cation exchange capacity, organic matter and N-status in soil. SC-BC considerably decreased the solubility of Pb to values lower than the toxic regulatory level of the toxicity characteristics leaching procedure extraction (5 mg L(-1)). The rise in soil pH caused by biochar application, and the increase of soil organic matter transformed the labile Pb into less available fractions i.e. "Fe-Mn oxides" and "organic" bound fractions. On the other hand, As was desorbed from Fe-Mn oxides, which resulted in greater mobility of As in the treated soil. We concluded that SC-BC and OP-BC could be used successfully for remediating soils highly contaminated with Pb. However, considerable attention should be paid when using it in soil contaminated with As. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Early-maturing soybean cropping system. III. Protein and oil contents and oil composition

    International Nuclear Information System (INIS)

    Kane, M.V.; Steele, C.C.; Grabau, L.J.; MacKown, C.T.; Hildebrand, D.F.

    1997-01-01

    Expanding production of early-maturing soybean [Glycine max (L.) Merrill] cultivars in the southeastern USA has exposed such cultivars to a wide range of environmental conditions during seed-fill. Temperatures during this growth stage influence levels of specific fatty acids, particularly of the unsaturated fatty acids. Our objective was to evaluate the grain quality responses of early-maturing cultivars to the wide range of planting dates in the southeastern USA. Protein and oil contents along with fatty acid profiles were assessed for cultivars from Maturity Group (MG) 00 through IV using late April mid-May early June, and late June planting dates on a well-drained Maury silt loam (fine, mixed, mesic Typic Paleudalf) in 1990 through 1993. Across years and cultivars. delayed planting increased protein content and linolenic acid levels and reduced oil content and oleic acid levels but had little or no influence on palmitic stearic or linoleic acid levels. The higher seed-fill temperatures associated with early planting were strongly correlated with increased oil content and oleic acid levels and reduced linolenic acid levels. Increasing seed-fill temperatures were closely associated with reduced linolenic acid levels for all six cultivars. However, the oleic acid response to seed-temperatures strongly depended on cultivar maturity. Oleic acid levels of early-maturing cultivars were much more sensitive to seed-fill temperatures than were those of later maturing cultivars. While other effects of environment on grain quality characteristics may be relatively small perhaps the quality of new low linolenic acid cultivars could be amplified through culture under the warmer conditions the southeastern USA

  8. Oxygen isotopic ratios of quartz from wind-erosive soils of southwestern United States in relation to aerosol dust

    Energy Technology Data Exchange (ETDEWEB)

    Sridhar, K.; Jackson, M.L.; Clayton, R.N.; Gillette, D.A.; Hawley, J.W.

    1978-01-01

    The oxygen isotopic ratios (expressed as parts per thousand relative to mean ocean water, SMOW, delta/sup 18/O) of the quartz from 13 soils undergoing much wind erosion during the study period of 1972-1975 in four southwestern states and from comparison areas were determined. The delta/sup 18/O for quartz from eight Texas (TX) and Arizona (AZ) soils range from 13.0 to 15.9 /sup 0///sub 00/. The quartz of the sands and silts coarser than 20 ..mu..m from three of the soils had delta/sup 18/O values ranging from 13.1 to 15.1 /sup 0///sub 00/, characteristic of an ultimate igneous-metamorphic origin. The delta/sup 18/O values increase greatly with decreasing particle size of quartz from three soils ranging from loamy fine sand to loam to clay in texture. The delta/sup 18/O of the 1-10 ..mu..m quartz fraction (aerosol size) ranged from 19.2 to 20.2 /sup 0///sub 00/ (19.55 +- 0.28 /sup 0///sub 00/; +- sigma) for the thirteen soils most affected by dust storms. The oxygen isotopic ratios of 1-10 ..mu..m quartz from three Hawaiian soils and two sediments from Lake Waiau occurring at 3,970 m altitude on the Mauna Kea summit on the Island of Hawaii give a delta/sup 18/O mean of 18.3 +- 0.2 /sup 0///sub 00/.

  9. Effect of composting and soil type on dissipation of veterinary antibiotics in land-applied manures.

    Science.gov (United States)

    Chen, Chaoqi; Ray, Partha; Knowlton, Katharine F; Pruden, Amy; Xia, Kang

    2018-04-01

    The objective of this study was to determine the fate of commonly used veterinary antibiotics in their naturally excreted form when manure-based amendments are applied to soil. Beef cattle were administered sulfamethazine, tylosin, and chlortetracycline and dairy cows were treated with pirlimycin. The resulting manure was composted for 42 d under static or turned conditions and applied at agronomic N rates to sandy, silt, and silty clay loam soils and compared with amendment with corresponding raw manures in sacrificial microcosms over a 120-day period. Antibiotic dissipation in the raw manure-amended soils followed bi-phasic first order kinetics. The first phase half-lives for sulfamethazine, tylosin, chlortetracycline, and pirlimycin ranged from 6.0 to 18, 2.7 to 3.7, 23 to 25, and 5.5-8.2 d, respectively. During the second phase, dissipation of sulfamethazine was negligible, while the half-lives for tylosin, chlortetracycline, and pirlimycin ranged from 41 to 44, 75 to 144, and 87-142 d, respectively. By contrast, antibiotic dissipation in the compost-amended soils followed single-phase first order kinetics with negligible dissipation of sulfamethazine and half-lives of tylosin and chlortetracycline ranging from 15 to 16 and 49-104 d, respectively. Pirlimycin was below the detection limit in the compost-amended soils. After incubating 120 d, antibiotics in compost-amended soils (up to 3.1 μg kg -1 ) were significantly lower than in manure-amended soils (up to 19 μg kg -1 , p soil type on the dissipation. Risk assessment suggested that composting can reduce antibiotic resistance selection potential in manure-amended soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Dairy heifer manure management, dietary phosphorus, and soil test P effects on runoff phosphorus.

    Science.gov (United States)

    Jokela, William E; Coblentz, Wayne K; Hoffman, Patrick C

    2012-01-01

    Manure application to cropland can contribute to runoff losses of P and eutrophication of surface waters. We conducted a series of three rainfall simulation experiments to assess the effects of dairy heifer dietary P, manure application method, application rate, and soil test P on runoff P losses from two successive simulated rainfall events. Bedded manure (18-21% solids) from dairy heifers fed diets with or without supplemental P was applied on a silt loam soil packed into 1- by 0.2-m sheet metal pans. Manure was either surface-applied or incorporated (Experiment 1) or surface-applied at two rates (Experiment 2) to supply 26 to 63 kg P ha. Experiment 3 evaluated runoff P from four similar nonmanured soils with average Bray P1-extractable P levels of 11, 29, 51, and 75 mg kg. We measured runoff quantity, total P (TP), dissolved reactive P (DRP), and total and volatile solids in runoff collected for 30 min after runoff initiation from two simulated rain events (70 mm h) 3 or 4 d apart. Manure incorporation reduced TP and DRP concentrations and load by 85 to 90% compared with surface application. Doubling the manure rate increased runoff DRP and TP concentrations an average of 36%. In the same experiment, P diet supplementation increased water-extractable P in manure by 100% and increased runoff DRP concentration threefold. Concentrations of solids, TP, and DRP in runoff from Rain 2 were 25 to 75% lower than from Rain 1 in Experiments 1 and 2. Runoff DRP from nonmanured soils increased quadratically with increasing soil test P. These results show that large reductions in P runoff losses can be achieved by incorporation of manure, avoiding unnecessary diet P supplementation, limiting manure application rate, and managing soils to prevent excessive soil test P levels. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  11. Using semi-variogram analysis for providing spatially distributed information on soil surface condition for land surface modeling

    Science.gov (United States)

    Croft, Holly; Anderson, Karen; Kuhn, Nikolaus J.

    2010-05-01

    The ability to quantitatively and spatially assess soil surface roughness is important in geomorphology and land degradation studies. Soils can experience rapid structural degradation in response to land cover changes, resulting in increased susceptibility to erosion and a loss of Soil Organic Matter (SOM). Changes in soil surface condition can also alter sediment detachment, transport and deposition processes, infiltration rates and surface runoff characteristics. Deriving spatially distributed quantitative information on soil surface condition for inclusion in hydrological and soil erosion models is therefore paramount. However, due to the time and resources involved in using traditional field sampling techniques, there is a lack of spatially distributed information on soil surface condition. Laser techniques can provide data for a rapid three dimensional representation of the soil surface at a fine spatial resolution. This provides the ability to capture changes at the soil surface associated with aggregate breakdown, flow routing, erosion and sediment re-distribution. Semi-variogram analysis of the laser data can be used to represent spatial dependence within the dataset; providing information about the spatial character of soil surface structure. This experiment details the ability of semi-variogram analysis to spatially describe changes in soil surface condition. Soil for three soil types (silt, silt loam and silty clay) was sieved to produce aggregates between 1 mm and 16 mm in size and placed evenly in sample trays (25 x 20 x 2 cm). Soil samples for each soil type were exposed to five different durations of artificial rainfall, to produce progressively structurally degraded soil states. A calibrated laser profiling instrument was used to measure surface roughness over a central 10 x 10 cm plot of each soil state, at 2 mm sample spacing. The laser data were analysed within a geostatistical framework, where semi-variogram analysis quantitatively represented

  12. Environmental Assessment, United States Air Force Proposed Lease Replacement for Scandia Elementary School, Travis Air Force Base, California

    Science.gov (United States)

    2015-09-01

    brown, and light gray loam 19-inches thick. The subsoil is mottled, light yellowish brown, yellowish brown, and pale brown clay 41-inches thick...areas of Solano loam and Pescadero clay loam. The Antioch soil has slightly concave slopes, and the San Ysidro soil has slightly convex slopes (Web...Infrastructure and utilities include transportation, water supply, sanitary sewage/wastewater natural gas, electrical, communications, and liquid fuels

  13. KC-46A Formal Training Unit (FTU) and First Main Operating Base (MOB 1) Beddown EIS. Volume 1

    Science.gov (United States)

    2014-03-01

    discharged into the sanitary sewer system. Most of the sanitary sewer system at Altus AFB is over 45 years old and constructed of vitrified clay ...drained (USDA 2002a, 2003). The textures of the Tillman-Hollister soils range from clay loam to clay , with the Hollister subsurface soils being more clayey...range from sandy to sandy loam to sandy clay loam, with the Nobscot soils having a more sandy nature, especially in the surface soils (Altus AFB 2009a

  14. Final KC-46A Formal Training Unit (FTU) and First Main Operating Base (MOB 1) Beddown EIS

    Science.gov (United States)

    2014-03-01

    years old and constructed of vitrified clay pipe or concrete. Of the sanitary sewer lines field surveyed in 2004 and 2007, approximately 85 percent...Hollister soils are very deep and well-drained (USDA 2002a, 2003). The textures of the Tillman-Hollister soils range from clay loam to clay , with...The textures of the Miles-Nobscot soils range from sandy to sandy loam to sandy clay loam, with the Nobscot soils having a more sandy nature

  15. Final Environmental Assessment for Establishment of a New C-130 Landing Zone for 58 SOW

    Science.gov (United States)

    2013-10-01

    sand about 10 inches thick. The subsoil is brown light sandy clay loam about 12 inches thick. The substratum is pink loam and sandy loam that has a...Madurez series soils is light brown loamy fine sand approximately 10 inches thick, with a brown light sandy clay loam subsoil about 12 inches thick...Closure Opening/Comments Count Sanitary Can w/folded seam 3” dia. x 4” ht. 1 Potted meat cans w/solder 2” dia. x 1 5/8” ht. ”Est-20-A” on base 2

  16. Relationship of bifenthrin sediment concentrations to grain size and total organic carbon in California waterbodies: implications for ecological risk.

    Science.gov (United States)

    Hall, Lenwood W; Anderson, Ronald D

    2014-12-01

    A summary analysis of data sets from six California waterbodies was conducted to determine the relationship of bifenthrin sediment concentrations to: % sand/gravel; % silt; % clay; % silt/clay and % total organic carbon (TOC). The relationship of TOC to % sand/gravel, % silt, % clay, and % silt/clay was also analyzed. Statistically significant and meaningful direct relationships were reported between bifenthrin and % TOC, % silt, % clay and % silt/clay while a significant and meaningful inverse relationship was reported between bifenthrin and % sand/gravel. A significant and meaningful inverse relationship was reported between % TOC and % sand/gravel, while a significant and meaningful direct relationship was reported between % TOC and % silt, % clay and % silt/clay. Significant bifenthrin sediment concentrations would not be expected in non-depositional (sand/gravel) areas which have been reported to be dominant in various streams in California's Central Valley and are also the preferred habitat for many benthic macroinvertebrate taxa.

  17. An application of the multibeam sounder for seabed backscattering analysis

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Raju, Y.S.N.

    signals are studied with the sediments like sand, clay and silt of smooth and rippled type. Study shows that the scattering effect is less with the sand bottom while compared with clay and silt type sediments...

  18. Download this PDF file

    African Journals Online (AJOL)

    influences their usability in construction works. The grain size distributions show that ADET I is silty-clayey very gravelly sand, having 23% clay and silt. 47% sand and 30% gravel compositions. Similarly, ADET 2 could be described as gravelly silt-clayey sand with 36% clay and silt. 52% sand and 12% gravel compositions.

  19. Tilting-connected symmetric algebras

    OpenAIRE

    Aihara, Takuma

    2010-01-01

    The notion of silting mutation was introduced by Iyama and the author. In this paper we mainly study silting mutation for self-injective algebras and prove that any representation-finite symmetric algebra is tilting-connected. Moreover we give some sufficient conditions for a Bongartz-type Lemma to hold for silting objects.

  20. Modelos de infiltración y funciones de pedotransferencia aplicados a suelos de distinta textura Infiltration models and pedotransfer functions applied to soils with different texture

    Directory of Open Access Journals (Sweden)

    Ana M Landini

    2007-12-01

    las hipótesis del modelo.The knowledge of the process of water infiltration in soil is important in the design of irrigation systems and in the prediction of the vulnerability to the contamination of soil and groundwater. Moreover, it is important to evaluate the efficiency of the hydrological models that predict the movement of water in soil. The objective of this study was to evaluate and to compare the goodness of fitting of Kostiakov-Lewis (K-L and Philip (Ph infiltration models to experimental data obtained from three soils: two of them at the Province of Buenos Aires, and the third one at the School of Agronomy's campus of the Buenos Aires University, (Argentina. Efficiency of Saxton and Rawls (SyR pedotransfer functions (FPT on the determination of the Green and Ampt (GA model input hydraulic parameters and the prediction of the soil-moisture release curve were analyzed too. K-L and Ph models fitted data with R² coefficient greater than 0.6. Then it was concluded that these models accurately describe the infiltration process of the studied soils. The highest basic infiltration rate (fo was 0.42 cm min-1 and corresponded to a silty clay soil with organic amendment, and for the other two soils (silt loam and clay loam were 0.03 and 0.07 cm min-1 respectively. For two of the studied soils, GA model obtained from input parameters determined with the FPT, predicted the infiltration process with an efficiency coefficient (CE greater than 0.8. However, at some cases, the fitting was not so good for dephts greater than 20 cm. For the silt loam soil, the FPT predicted the soil-moisture release curve with an CE close to 0.9. It might be suggested to carry out a preliminary few number of infiltration tests on any soil under study, and analyze the FPT and the GA model goodness of fit. In this way, the convenience of using these models could be evaluated.