scholarly journals Distribuição Espacial da Condutividade Elétrica e Matéria Orgânica em um Solo Neossolo Flúvico (Spatial Distribution of Electrical Conductivity and Organic Matter in a Soil Fluvic Neosol)

2013 ◽  
Vol 6 (4) ◽  
pp. 764 ◽  
Author(s):  
Jucicléia Soares da Silva ◽  
Abelardo Antônio de Assunção Montenegro ◽  
Ênio Farias de França e Silva ◽  
Carolyne Wanessa Lins de Andrade ◽  
José Roberto Lopes da Silva
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Precision Agriculture ◽  
Spherical Model ◽  
Contour Maps ◽  
Saturation Extract ◽  
Cultivar Selection

A agricultura de precisão permite, pelo uso de delimitação de lavouras por coordenadas georreferenciadas, um planejamento mais racional do manejo de nutrientes, incidência de pragas, umidade do solo, plantas daninhas, além de seleção de cultivares em função de sua adaptabilidade às diferentes condições identificadas nas áreas cultivadas. Com isso, o objetivo do presente trabalho foi avaliar a distribuição espacial da condutividade elétrica do extrato de saturação, carbono orgânico total e matéria orgânica em um solo Neossolo Flúvico. O experimento foi conduzido em uma área com malha regular 4 x 4 m, totalizando com 49 pontos, onde foram coletadas amostras nas camadas de 0- 0,20 m para analisar a condutividade elétrica do extrato de saturação, carbono orgânico total e matéria orgânica. As variáveis foram analisadas por meio da estatística descritiva e de ferramentas de geoestatística. As variáveis apresentaram distribuição normal, os semivariogramas se ajustaram a um modelo esférico, a variabilidade do carbono orgânico total e matéria orgânica apresentaram moderadas, a condutividade elétrica do extrato de saturação apresentou fraca dependência espacial. Os mapas de isolinhas apresentaram homogeneidade e similaridade, os mapas condutividade elétrica do extrato de 0-0,20 m foram inversamente proporcionais aos da matéria orgânica e do carbono orgânico. A B S T R A C T Precision agriculture allows, by the use of delimitation of crops for georeferenced coordinates, more rational planning of the management of nutrients, pests, soil moisture, weeds, and cultivar selection due to its adaptability to different conditions in the areas identified cultured. With it, the objective of this study was to evaluate the spatial distribution of the electrical conductivity of the saturation extract, total organic carbon and organic matter in soil Fluvic Neosol. The experiment was conducted in an area with regular mesh 4 x 4 m, with a total of 49 points, samples were collected in layers from 0 to 0.20 m to analyze the electrical conductivity of the saturation extract, total organic carbon and organic matter. The variables were analyzed using descriptive statistics and geostatistical tools. The variables were normally distributed, the semivariogram adjusted to a spherical model, the variability of total organic caborn and organic matter showed a moderate electrical conductivity of the saturation extract showed weak spatial dependence. The contour maps showed homogeneity and similarity maps the electrical conductivity of the extract of 0-0.20 m was inversely proportional to the organic matter and organic carbon. Key-Words: Geostatistics, salinity, total organic carbon, organic matter

scholarly journals A Study of the Spatial Heterogeneity of Some Chemical Properties of Terabhor Back Using GIS

2019 ◽  
Vol 27 (1) ◽  
pp. 408-426
Author(s):  
Wurood Amer Abdul Amir ◽  
Amal Radi Jubair
Keyword(s):  
Electrical Conductivity ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Spatial Heterogeneity ◽  
Chemical Properties ◽  
Spherical Model ◽  
Distribution Maps ◽  
American System ◽  
Circular Model ◽  
Random Samples

  Done studying the variability of the soils And the heterogeneity of the characteristics of the soils of the Euphrates, where 6 boreons were described and described the horizons of the pidoons as morphological and fundamental, as well as obtaining random samples on four equal depths 25-0 cm, 50-25 cm, 75-50 cm and 100-75 cm. The results of spatial heterogeneity Turbidity and Spatial Distribution Maps The heterogeneity of all the characteristics of chemical faecal soil is indicated by the results. The results indicate the variance of the horizons in the moving distance that describe the heterogeneity of the chemical properties, Electrical conductivity of EC Ranging between 0.48-5.46 and gypsum Ranging between 0.15 - 4.61 qualities more heterogeneous, and then followed by organic matter Ranging between 0.27-4.50 and CEC Ranging between 18.66-38.42 .                                                                                         The least heterogeneous properties were soil pH Ranging between 7.05- 7.62, followed by calcium carbonate Ranging between 284.28 - 438.71, where the range was high                                                                                                         The results showed that the appropriate model describing the heterogeneity of the chemical properties was the circular model, the appropriate model for describing its variation by 54%, followed by the spherical model of 43% and the gussin model of 4%. The soil of the study according to the modern American system 2014 is classified into two levels: Entisols and Mollisols .                                                                                              

scholarly journals Characterization of organic matter from a stratigraphic sequence intercepted by the Nemo-1X well, Mozambique: Potential for hydrocarbon generation

2018 ◽  
Vol 36 (5) ◽  
pp. 1157-1171
Author(s):  
Agostinho Mussa ◽  
Deolinda Flores ◽  
Joana Ribeiro ◽  
Ana MP Mizusaki ◽  
Mónica Chamussa ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Hydrocarbon Exploration ◽  
Published Data ◽  
Organic Carbon Content ◽  
Hydrocarbon Generation ◽  
Offshore Area ◽  
Type Iii ◽  
Kerogen Type

The Mozambique Basin, which occurs onshore and offshore in the central and southern parts of Mozambique, contains a thick sequence of volcanic and sedimentary rocks that range in age from the Jurassic to Cenozoic. This basin, along with the Rovuma basin to the north, has been the main target for hydrocarbon exploration; however, published data on hydrocarbon occurrences do not exist. In this context, the present study aims to contribute to the understanding of the nature of the organic matter of a sedimentary sequence intercepted by the Nemo-1X exploration well located in the offshore area of the Mozambique Basin. The well reached a depth of 4127 m, and 33 samples were collected from a depth of 2219–3676 m ranging in age from early to Late Cretaceous. In this study, petrographic and geochemical analytical methods were applied to assess the level of vitrinite reflectance and the organic matter type as well as the total organic carbon, total sulfur, and CaCO3 contents. The results show that the total organic carbon content ranges from 0.41 to 1.34 wt%, with the highest values determined in the samples from the Lower Domo Shale and Sena Formations, which may be related to the presence of the solid bitumens that occur in the carbonate fraction of those samples. The vitrinite random reflectances range from 0.65 to 0.86%Rrandom, suggesting that the organic matter in all of the samples is in the peak phase of the “oil generation window” (0.65–0.9%Rrandom). The organic matter is mainly composed of vitrinite and inertinite macerals, with a minor contribution of sporinite from the liptinite group, which is typical of kerogen type III. Although all of the samples have vitrinite reflectances corresponding to the oil window, the formation of liquid hydrocarbons is rather limited because the organic matter is dominated by gas-prone kerogen type III.

scholarly journals Sources and export of particle-borne organic matter during a monsoon flood in a catchment of northern Laos

2015 ◽  
Vol 12 (4) ◽  
pp. 1073-1089 ◽  
Author(s):  
E. Gourdin ◽  
S. Huon ◽  
O. Evrard ◽  
O. Ribolzi ◽  
T. Bariac ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Particulate Organic Matter ◽  
Rainy Season ◽  
Overland Flow ◽  
Specific Yield ◽  
Main Stream ◽  
Δ13c And Δ15n ◽  
Suspended Organic Matter

Abstract. The yields of the tropical rivers of Southeast Asia supply large quantities of carbon to the ocean. The origin and dynamics of particulate organic matter were studied in the Houay Xon River catchment located in northern Laos during the first erosive flood of the rainy season in May 2012. This cultivated catchment is equipped with three successive gauging stations draining areas ranging between 0.2 and 11.6 km2 on the main stem of the permanent stream, and two additional stations draining 0.6 ha hillslopes. In addition, the sequential monitoring of rainwater, overland flow and suspended organic matter compositions was conducted at the 1 m2 plot scale during a storm. The composition of particulate organic matter (total organic carbon and total nitrogen concentrations, δ13C and δ15N) was determined for suspended sediment, soil surface (top 2 cm) and soil subsurface (gullies and riverbanks) samples collected in the catchment (n = 57, 65 and 11, respectively). Hydrograph separation of event water was achieved using water electric conductivity and δ18O measurements for rainfall, overland flow and river water base flow (n = 9, 30 and 57, respectively). The composition of particulate organic matter indicates that upstream suspended sediments mainly originated from cultivated soils labelled by their C3 vegetation cover (upland rice, fallow vegetation and teak plantations). In contrast, channel banks characterized by C4 vegetation (Napier grass) supplied significant quantities of sediment to the river during the flood rising stage at the upstream station as well as in downstream river sections. The highest runoff coefficient (11.7%), sediment specific yield (433 kg ha−1), total organic carbon specific yield (8.3 kg C ha−1) and overland flow contribution (78–100%) were found downstream of reforested areas planted with teaks. Swamps located along the main stream acted as sediment filters and controlled the composition of suspended organic matter. Total organic carbon specific yields were particularly high because they occurred during the first erosive storm of the rainy season, just after the period of slash-and-burn operations in the catchment.

scholarly journals Development of Upwelling during the Sedimentary Period of the Organic-Rich Shales in the Wufeng and Longmaxi Formations of the Upper Yangtze Region and Its Impact on Organic Matter Enrichment

2019 ◽  
Vol 7 (4) ◽  
pp. 99 ◽  
Author(s):  
Shao-Ze Zhao ◽  
Yong Li ◽  
Hua-Jun Min ◽  
Tong Wang ◽  
Zhou Nie ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Biogenic Silica ◽  
Vertical Direction ◽  
Burial Depth ◽  
Mineral Component ◽  
Longmaxi Formation ◽  
Component Content ◽  
Upwelling Intensity

This study uses logging data, mineral component content, total organic carbon (TOC) content, and microscopic characteristics of the organic-rich shales in the Wufeng and Longmaxi Formations, as well as data reported by other researchers, to demonstrate that upwelling has played an important role in the organic matter enrichment. The results show that (1) the organic-rich shales of Well N211 in the Upper Yangtze region are located in the Wufeng Formation and the lower Longmaxi Formation, with a burial depth between 2308–2357 m. (2) The organic-rich shales are enriched in biogenic silica. (3) Based on paleogeographic location and characteristics of organisms, this study determines that upwelling occurred during the deposition of the organic-rich shales in the Wufeng and Longmaxi Formations, promoting the enrichment of organic matter in the shales. (4) The upwelling intensity gradually increased from the sedimentary period of the organic-rich shales in the mid-lower Wufeng Formation to the sedimentary period of the Guanyinqiao Member, and then decreased gradually from the sedimentary period of the Guanyinqiao Member to the sedimentary period of the organic-rich shales in the Longmaxi Formation, and leads to the different enrichment of organic matter in the vertical direction. The different developments of upwelling led to the coexistence of both high and low TOC contents in the Guanyinqiao Member along the vertical direction.

scholarly journals Short-Term Changes in Fertility Attributes and Soil Organic Matter Caused by the Addition of EM Bokashis in Two Tropical Soils

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Carlos Eduardo Pacheco Lima ◽  
Mariana Rodrigues Fontenelle ◽  
Luciana Rodrigues Borba Silva ◽  
Daiane Costa Soares ◽  
Antônio Williams Moita ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Poultry Manure ◽  
Principal Component ◽  
Tropical Soils ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Chemical Attributes

The present work aimed to evaluate the behavior of ten fertility attributes of soil organic matter physical fractions and total organic carbon upon addition of three EM Bokashis to a Rhodic Ferralsol (FRr) and a Dystric Cambisol (CMd). An experiment was carried out in greenhouse in which the soils were placed into plastic trays and cultivated with tomato. A completely randomized design was used with four repetitions and factorial scheme of 2 × 3 + 2, consisting of two soils (FRr and CMd), three EM Bokashis (Poultry Manure Bokashi (BPM); CNPH Bokashi (BC); and Cattle Manure Bokashi (BCM)), and two controls (both soils without addition of Bokashi). The following fertility attributes were evaluated: pH, Ca2+, Mg2+, K+, Na+, P, SB, H + Al, CEC, andV. Particulate organic carbon (POC) and mineral-associated organic carbon (MOC) and total organic carbon (TOC) were also investigated. Finally, the Principal Component Analysis was conducted in order to identify possible patterns related to soils when fertilized with EM Bokashi. The addition of EM Bokashi increased the soil fertility and contents of POC. Different EM Bokashi presents distinguished effects on each soil. The PCA suggests that BPM presents higher capacity to modify the analyzed chemical attributes.

scholarly journals Composting of Calotropis gigantea Leaves In Presence of Sheep Dung

2015 ◽  
Vol 10 (1) ◽  
pp. 281-284 ◽  
Author(s):  
Mayur Shah ◽  
Jaldip Kansara ◽  
Prateek Shilpkar
Keyword(s):  
Electrical Conductivity ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Total Nitrogen ◽  
Available Phosphorus ◽  
Calotropis Gigantea ◽  
Almost Everywhere ◽  
Plant Grown ◽  
Economic Use

Calotropis gigantea is a plant grown almost everywhere and has no economic use. Leaves of Calotropis gigantea plants were composted with sheep dung. Composting conditions were maintained and samples were withdrawn at 30, 60 and 90 days of composting and analysed for pH, electrical conductivity, Ca2+, Mg2+, Cl1-, total organic carbon, total nitrogen, available phosphorus and available potassium. Results show that contents of these parameters changes with time and at 90 days nutrient rich compost is obtained with decreased concentration of chloride.

scholarly journals Dynamic climate-driven controls on the deposition of the Kimmeridge Clay Formation in the Cleveland Basin, Yorkshire, UK

2019 ◽  
Author(s):  
Elizabeth Atar ◽  
Christian März ◽  
Andrew Aplin ◽  
Olaf Dellwig ◽  
Liam Herringshaw ◽  
...  
Keyword(s):  
Organic Matter ◽  
Trace Metals ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Distal Part ◽  
Hadley Cell ◽  
Redox Conditions ◽  
Climate Modelling ◽  
Lower Variability ◽  
Clay Formation

Abstract. The Kimmeridge Clay Formation (KCF) is a laterally extensive, total organic carbon-rich succession deposited throughout Northwest Europe during the Kimmeridgian–Tithonian (Late Jurassic). Here we present a petrographic and geochemical dataset for a 40 metre-thick section of a well-preserved drill core recovering thermally-immature deposits of the KCF in the Cleveland Basin (Yorkshire, UK), covering an interval of approximately 800 kyr. The new data are discussed in the context of depositional processes, sediment source and supply, transport and dispersal mechanisms, water column redox conditions, and basin restriction. Armstrong et al. (2016) recently postulated that an expanded Hadley Cell, with an intensified but alternating hydrological cycle, heavily influenced sedimentation and total organic carbon (TOC) enrichment, through promoting the primary productivity and organic matter burial, in the UK sectors of the Boreal Seaway. Consistent with such climate boundary conditions, petrographic observations, total organic carbon and carbonate contents, and major and trace element data presented here indicate that the KCF of the Cleveland Basin was deposited in the distal part of the Laurasian Seaway. Depositional conditions alternated between three states that produced a distinct cyclicity in the lithological and geochemical records: lower variability mudstone intervals (LVMIs) which comprise of clay-rich mudstone, TOC-rich sedimentation, and carbonate-rich sedimentation. The lower variability mudstone intervals dominate the studied interval but are punctuated by three ~ 2–4 m thick intervals of alternating TOC-rich and carbonate-rich sedimentation (here termed higher variability mudstone intervals, HVMIs). During the lower variability mudstone intervals, conditions were quiescent with oxic to sub-oxic bottom water conditions. During the higher variability mudstone intervals, highly dynamic conditions resulted in repeated switching of the redox system in a way similar to the modern deep basins of the Baltic Sea. During carbonate-rich sedimentation, oxic conditions prevailed, most likely due to elevated depositional energies at the seafloor by current/wave action. During TOC-rich sedimentation, anoxic-euxinic conditions led to an enrichment of redox sensitive/sulphide forming trace metals at the seafloor and a preservation of organic matter, and an active Mn-Fe particulate shuttle delivered redox sensitive/sulphide forming trace metals to the seafloor. In addition, based on TOC–S–Fe relationships, organic matter sulphurisation appears to have increased organic material preservation in about half of the analysed samples throughout the core, while the remaining samples were either dominated by excess Fe input into the system or experienced pyrite oxidation and sulphur loss during oxygenation events. New Hg/TOC data do not provide evidence of increased volcanism during this time, consistent with previous work. Set in the context of recent climate modelling, our study provides a comprehensive example of the dynamic climate-driven depositional and redox conditions that can control TOC and metal accumulations in the distal part of a shallow epicontinental sea, and is therefore key to understanding the formation of similar deposits throughout Earth's history.

scholarly journals A New Evaluation Method of Total Organic Carbon for Shale Source Rock Based on the Effective Medium Conductivity Theory

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Jian Fu ◽  
Xuesong Li ◽  
Yonghe Sun ◽  
Qiuli Huo ◽  
Ting Gao ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Clay Minerals ◽  
Pore Water ◽  
Effective Medium ◽  
Source Rocks ◽  
Model Parameters ◽  
Hydrocarbon Generation ◽  
Tight Sandstone

In the evaluation of source rocks, the total organic carbon (TOC) is an important indicator to evaluate the hydrocarbon generation potential of source rocks. At present, the commonly used methods for assessing TOC include △ log R and neural network method. However, practice shows that these methods have limitations in the application of unconventional intervals of sand-shale interbeds, and they cannot sufficiently reflect the variation of TOC in the vertical direction. Therefore, a total organic carbon (TOC) evaluation model suitable for shale and tight sandstone was established based on the effective medium symmetrical conduction theory. The model consists of four components: nonconductive matrix particles, clay minerals, organic components (solid organic matter and hydrocarbons), and pore water. The conductive phase in the model includes clay minerals and pore water, and other components are treated as nonconductive phases. When describing the conductivity of rock, each component in the model is completely symmetrical, and anisotropic characteristics of each component are considered. The model parameters are determined through the optimization method, and the bisection iteration method is used to solve the model equation. Compared with the classic TOC calculation method, the new model can evaluate the abundance of organic matter in shale and tight sandstone, which provides a new option to assess the TOC of rocks based on logging methods.

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