Percentage Of Organic Carbon Research Articles

Propiedades físicas y químicas del suelo urbano del Bosque San Juan de Aragón, Ciudad de México

Ante la falta de estudios sobre suelos urbanos en México, en el presente trabajo se evaluaron ocho propiedades físicas y químicas empleadas por el Indicador Condición de Suelo del FIA (Programa Nacional de Inventario y Análisis Forestal, de Estados Unidos), para determinar la calidad de los suelos y su papel en el desarrollo de las especies arbóreas del Bosque de San Juan de Aragón. Las propiedades evaluadas y analizadas en términos horizontales y verticales, fueron: pH, conductividad eléctrica, contenido de sales, textura, densidad aparente, y porcentajes de materia orgánica, carbono orgánico y espacio poroso. Se colectaron 96 muestras de suelo sobre 28 sitios de muestreo de 0.1 ha, a tres profundidades, 0-5, 5-10 y 10‑15 cm. El pH promedio del suelo fue 7.2; conductividad eléctrica, 0.51 dS m-1; densidad aparente, 1.02 g cm-3; espacio poroso, 61.84%; sales disueltas totales, 327.20 mg L-1; materia orgánica, 3.6% y carbono orgánico, 2.63%, así como una clase textural franca. Los suelos del área de estudio presentaron variabilidad vertical para densidad aparente, espacio poroso, contenido de materia orgánica, carbono orgánico, conductividad eléctrica y sales solubles, y fueron relativamente homogéneos en sentido horizontal. Con excepción de la materia orgánica, el resto de las propiedades presentaron valores aceptables para el buen desarrollo de las diferentes especies arbóreas presentes en el bosque e identif icadas en estudios previos. La medición de las propiedades evaluadas, permitió obtener un panorama real sobre la capacidad de este suelo urbano para funcionar como soporte adecuado en el desarrollo de especies leñosas.

Toward Improved Accuracy of Remote Sensing Approaches for Quantifying Suspended Sediment: Implications for Suspended‐Sediment Monitoring

AbstractBecause of the high logistical and financial costs of direct measurements of riverine suspended sediment, remote sensing is increasingly used to supplement the direct‐observation record. The accuracy of this method is poorly constrained, and its potential as a tool for understanding river sediment transport is thus limited. We introduce and apply global‐scale methods for estimating depth‐integrated suspended‐sediment concentrations (SSCs) using Landsat 5 and 7 satellite imagery calibrated with 134,697 in situ SSC measurements. We account for river‐to‐river variability in the relationship between water optical properties and SSC by (a) categorizing rivers using unsupervised K‐means clustering and/or (b) correcting calibration estimates for individual rivers using local in situ measurements of SSC, suspended‐sediment grain size, and percent organic carbon (POC). In the absence of site‐specific in situ SSC measurements, clustering rivers reduces the average relative error of SSC estimates from 97% to 73%. We show that as few as five site‐specific in situ measurements combined with our algorithm further reduces average relative error to 49% and average relative at‐a‐station bias in SSC to 7%. Little additional improvement in accuracy or bias is gained by including measurements of percent sand or POC of the suspended sediment. Since only modest additional accuracy is gained after ~5–10 paired in situ SSC measurements and satellite observations, sampling campaigns should prioritize limited sampling at diverse locations rather than intensive sampling at a limited number of sites. In addition, we publish standalone calibrations for 151 rivers made solely with in situ SSC measurements local to those sites.

A GEOPEDOLOGICAL APPROACH TO SOIL CLASSIFICATION TO CHARACTERIZE SOILS OF UPPER KABETE CAMPUS FIELD, UNIVERSITY OF NAIROBI, KENYA

<p><strong>Background. </strong>The study area exhibits a first class catena having homogenous parent material and forming a spatial continuum. Functionally and taxonomically distinct<em> </em>soils result from differences in drainage and lateral movement of materials in the soil. <strong>Objective.</strong> To classify the soils using a geopedological approach which involves a strong relationship between pedology and geomorphology. <strong>Methodology.</strong> The area was delineated into Soil Mapping Units (SMUs) through augering into soils defined by different macro-relief. Mapping units were demarcated according to slope categories namely 0 to 5%, 5 to 8%, 8 to 16%, 16 to 30% and >30% connoted as flat to gently undulating (AB), undulating (C), rolling (D), moderately steep (E) and steep (F) respectively. Profile pits were dug in the five identified mapping units using Stratified Random Sampling technique. Identified SMUs include UmIr/F, UmIr/E, UxIr/D, UxIr/C and UxIr/AB in the order of decreasing slope gradient. The first entry represents the physiographic unit (Uplands, U), followed by physiographic position (lower middle uplands, m or uplands, undifferentiated levels, x), geology (I), color (r) and slope class respectively. A soil map with a legend describing the mapping units was produced using a scale of 1:10000. Topographic influence on soil properties was presented by Pearson’s correlation coefficient (r) with p-value included where the influence was significant. Statistical analysis was done using IBM SPSS 25<sup>th</sup> edition and MS Excel. <strong>Results.</strong> All the mapping units are well drained and deep to very deep (>80 cm). The color of the upper B horizon is predominantly dark reddish brown. The texture of top horizon is clay in UmIr/F and UmIr/E and is clay loam to clay, sandy clay loam to clay and loam to clay loam in UxIr/D, UxIr/C and UxIr/AB respectively, lucidly exposing the influence of topography on the depth of clay illuviation (clay: r = 0.724; p ≤ 0.01). The structure is predominantly subangular blocky throughout the profiles with the top horizon of cultivated areas having predominantly granular structure. Saturated hydraulic conductivity (K<sub>sat</sub>) generally decreases with increasing clay content down the profiles and the bulk density ranges from 0.9 to 1.2gcm<sup>-3</sup>. Means of soil reaction of top horizons generally slightly decrease with decreasing gradient (r = 0.231) having lower values in cultivated areas. Percent organic carbon regularly decreases down the profiles with higher values in uncultivated, steeper areas (r = 0.521; p ≤ 0.05). In the top horizon: Total nitrogen is predominantly medium across the study area ranging from 0.2 to 0.56% (r = 0.185) and follows the organic carbon trend; Available phosphorus is deficient (<20 ppm) in the study area. Bases are sufficiently to richly supplied while micronutrients are richly supplied. All soils are non-saline and non-sodic; the cation exchange capacity (CEC) soil is predominantly medium across the profiles ranging from 15 to 27.6 cmol(+)/kg with values increasing slightly with increasing slope (r = 0.320). Based on data collected from description of the profiles and physicochemical data of the soils and according to IUSS Working Group WRB (2014) soil classification legend, the soils were classified as Mollic Nitisols. <strong>Implications.</strong> The soils are generally fertile for crop production but organic manure is recommended to buffer the acidic soil reaction, improve nitrogen and phosphorus sources. <strong>Conclusion.</strong> Soil characterization, land evaluation and precise input application are encouraged.</p>

Using fig and eucalyptus for ecosystem restoration and management: good choices with carbon storage ability.

Eucalyptus (Eucalyptus camaldulensis) and fig (Ficus carica) are considered as two of the most important forest species worldwide with nutritional values. This study was carried out in the Ahoochar region, during 2015-2017.This study was conducted to compare the ability of fig and eucalyptus in carbon sequestration as well as some of soil characteristics. This study was conducted as factorial experiment within a complete randomized design. According to the obtained results, fig trees have higher ability of carbon sequestration compared with eucalyptus. Soil of fig trees had a higher pH, bulk density, organic matter, organic carbon, and carbon sequestration compared with eucalyptus. However, the electrical conductivity (EC) of eucalyptus soil was significantly higher than fig. The amounts of organic carbon, organic matter, and carbon sequestration at the soil depth of 0-15cm were significantly higher than the depth of 15-30. Shallower soils contained higher percentages of organic carbon in comparison with deeper soils, and there was a significant difference between the depths of 0-15cm and 15-30cm which contained 1.72% and 0.87% of organic carbon, respectively. The highest percentage of organic carbon was measured in the fig soil at a depth of 0-15cm (2.33%), whereas the lowest percentage (0.58%) was measured in the control soil at 15-30cm. In total, fig tree with a good ability in carbon sequestration can be a good candidate for the forest management and rehabilitation especially in dry and semi dryland. Graphical abstract.

Assessment of Lagos soils for some persistent organic Pollutants

Contamination of Lagos soils with persistent, bioaccumulative and toxic micropollutants (PBTs) may not only affect the non-target species residing in the soil, but also raises the concern of the possibility of the chemicals finding their way into the Lagoon and other water courses via soil run-off and leaching. In this study, soil samples were collected from three busy areas of Lagos (Apapa, Okobaba and Iddo) and analyzed for Polychlorinated Biphenyls (PCBs), Organochlorine pesticides (OCS), and Polycyclic Aromatic Hydrocarbons (PAHs). Gas Chromatography with Mass Selective Detector (GC/MSD) was used for the analyses. Iddo had the highest percentage organic carbon content of 39.39% with highest total PAHs of 2,706.93 ng/g. The highest total PCBs of 23.63 ng/g was found at Apapa 3 which was one of the three sampling points in Apapa. PCB 74 was the onlyPCB found in all the soil samples and ranged between 3.55 ng/g and 23.64 ng/g at Apapa 1 and Apapa 2 respectively. High concentrations of the following organic compounds were also obtained at the following locations- naphthalene (1,625.10 ng/g) at Iddo; dichlorodiphenyldichloroethylene (p,p'DDE ), (117.98 ng/g) at Okobaba, and PCB 74 (23.63 ng/g) at Apapa 1. The results obtained showed that the higher the municipal activity, the higher the percentage organic carbon content.
 Key words: Bioaccumulative and toxic micropollutants, Gas chromatography/Mass selective detector, Persistent organic carbon, Soil organic pollutants

The Potential Corrosiveness of Soil Physico- Chemical Properties on Pipelines

Aim: The study was conducted to determine the potential corrosiveness of selected soil physicochemical properties on pipelines.
 Study Design: Soil samples were randomly collected around five pipeline locations with control from a farmland.
 Duration of Study: The study lasted for three months.
 Methodology: Standard methods were adopted in the collection of samples and the determination of the physicochemical properties of the samples.
 Results: Metallic pipelines undergo more regular corrosion because they are used in environments like soil where they are chemically unstable. Soil physicochemical properties such as soil moisture, texture, pH and temperature, sulphate, chloride, redox potential and resistivity were determined. The pH of the five soil samples was acidic (pH =4.0 – 6.5), The highest moisture content was 22.88% while the lowest was 9.84%. The soil samples the potential of being corrosive to the buried galvanized-steel and cast-iron pipes. Delta Steel Company (DSC) roundabout had the highest sulphate content of 724.13 mg/kg while the lowest was Oleh with 156.14 mg/kg. The highest percentage of Total Organic Carbon was 0.52% and the lowest was 0.40%.
 Conclusion: Besides pipeline vandalization, pipeline corrosion may likely be one of the major causes of oil spillage in localized underground pipelines within the region. There is, therefore, an urgent need for computerized sensors to assist in the monitoring of underground pipeline integrity in Nigeria.

Tree biomass and carbon stock: understanding the role of species richness, elevation, and disturbance

Six elevation zones viz., MHF 1 to MHF 6 (Mahendragiri Hill Forest) starting from 229 to > 1505 m asl were assessed to estimate the biomass and carbon stock in tropical dry deciduous forests of Mahendragiri Hills, Eastern Ghats. It aims at establishing a relationship among stem density, biomass, and carbon stock along the elevation gradient and disturbance regime. Each zone considered twenty plots for the investigation (0.05 ha; 50 × 10 m). All the trees ≥ 1 cm girth at breast height were enumerated, and the non-harvest method was used to assess the biomass. The tree biomass ranged from 129.05 Mg/ha in MHF 1 to 255.87 Mg/ha in MHF 2; with the total carbon stock also followed the same trend. The Soil Organic Carbon percentage ranged from 0.70 ± 0.24 to 1.43 ± 0.15 and 0.55 ± 0.22 to 1.13 ± 0.42 in the top and bottom layers, respectively. The results suggest the insufficiency of significant influence on tree biomass by elevation, species richness, diversity, and stem density. The disturbance score generated from the quantification of the frequency of occurrence of different disturbances showed high values in MHF 3 and MHF 1 among the six elevation zones. The disturbance has a more significant impact on the biomass. The highest carbon stock accumulation in MHF 2 could be due to the presence of abundant, large-diameter trees. The total SOC estimated in different elevation zones showed a strong significant positive correlation with elevation. The present research would give an insight for proper management of the declining tropical dry deciduous forests.

Digital mapping of soil moisture retention properties using solely satellite-based data and data mining techniques

Soil moisture retention is an important environmental factor that controls water availability in agro-ecosystems. Comprehensive information on spatial distribution and patterns of soil properties controlling moisture retention such as organic carbon (OC), clay content, and saturation percentage (SP) are crucial for effective land management and sustainable development. This study seeks to employ two data mining algorithms named Multivariate Adaptive Regression Splines (MARS) and Gene Expression Programming (GEP) as predictive models in digital soil mapping (DSM) and quantify the associated uncertainty at a grid resolution of 30 m using satellite-based covariates. For each model, the features selected based on their interior algorithm during the training of the models. The performance and accuracy of MARS and GEP were evaluated through nine statistical/quantitative and graphical criteria, including mean error (ME), mean absolute error (MAE), Root mean squared error (RMSE) and coefficient of determination (R2), relative RMSE (RMSE%), Taylor diagram, scatter, curve fitting, and point density plots. For each model, the prediction maps of soil properties and their associated uncertainty maps were generated. The results revealed that MARS outperformed GEP in providing predictions with superior performance and accuracy. Moreover, MARS performed better in showing the spatial distributions and patterns of all the studied soil properties. In addition, the MARS model produced less prediction uncertainty and can predict soil moisture retention properties more accurately. This study highlights the key role of data mining/numerical modeling algorithms as predictive models in DSM toward the most accurate predictions. Moreover, the study expressed the capabilities of remote sensing derived data in predicting complex soil properties. This study opened a new research line for accurate DSM.

A permutation approach to the analysis of spatiotemporal geochemical data in the presence of heteroscedasticity

AbstractThis paper proposes a novel nonparametric approach to model and reveal differences in the geochemical properties of the soil, when these are described by space–time measurements collected in a spatial region naturally divided into two parts. The investigation is motivated by a real study on a space–time geochemical data set, consisting of measurements of potassium chloride pH, water pH, and percentage of organic carbon collected during the growing season in the agricultural and forest areas of a site near Brno (Czech Republic). These data are here modeled as spatially distributed functions of time. A permutation approach is introduced to test for the effect of covariates in a spatial functional regression model with heteroscedastic residuals. In this context, the proposed method accounts for the heterogeneous spatial structure of the data by grounding on a permutation scheme for estimated residuals of the functional model. Here, a weighted least squares model is fitted to the observations, leading to asymptotically exchangeable and, thus, permutable residuals. An extensive simulation study shows that the proposed testing procedure outperforms the competitor approaches that neglect the spatial structure, both in terms of power and size. The results of modeling and testing on the case study are shown and discussed.

Assessment of organic matter preservation and coastal constraints (SE Algarve, Portugal)

Surface sediments were sampled at 18 stations from 7 to 64 m depth off the SE coast of Algarve to characterize the organic matter contents in the inner and middle shelf. For each sediment sample, grain size, mineralogy and total organic carbon analyses were carried out, as well as pigment analyses (19’ but-fucoxanthin, fucoxanthin, 19’ hex-fucoxanthin, chlorophyll-a, chlorophyll-b, pheophytin-a, pheophorbide-a, alpha-carotene, beta-carotene, anteraxanthin, diadinoxanthin, diatoxanthin, lutein and zeoxanthin). In addition, the ratios between each pigment and the total organic carbon (TOC) percentage, and between the chlorophyll-a concentration and the pheophytin-a and the pheophorbide-a concentrations were calculated to establish pigment indices. A Multidimensional scaling (MDS) analysis highlights three regions in the SE coast of Algarve according to depth, percentages of TOC, sediment grain size and mineralogy, concentration of pigments highly susceptible to degradation, concentration of refractory pigments (pigments not susceptible to degradation) and different preservation conditions (based on the pigment index values). The results highlight a correlation between pigments concentration and environmental variables, showing the eastern limit of West coastal upwelling plumes influence along the Algarve continental shelf.

Removal of disinfection by-products and their precursors during drinking water treatment processes.

In this study, we investigated the control efficiency of a wide variety of disinfection by-products (DBPs) (including trihalomethanes [THMs], haloacetic acids [HAAs], haloacetonitiles [HANs], haloketones [HKs], haloaldehydes [Has], and trihalonitromethanes [THNMs]) with different drinking water treatment processes including pre-ozonation, coagulation-sedimentation, sand filtration, and ozone combined with biological activated carbon (O3 -BAC) advanced treatment processes. The assessment of the treatment efficiency regarding the removal of organic matter was measured by the excitation emission matrix (EEM) spectra. There was a superior efficiency in reducing the formation of DBPs and their precursors by different drinking water treatment processes. Though some DBPs such as THMs could be promoted by ozonation, these by-products from ozonation could be degraded by the following BAC filtration process. In addition, the organic matter from the aromaticity, fulvic acid-like, protein, and soluble microbial by-products-like regions could be further degraded by the O3 -BAC treatment. PRACTITIONER POINTS: A wide variety of DBPs in different drinking water treatment processes was investigated. The treatment efficiency regarding the removal of organic matter was measured. Some DBPs such as THMs and HAAs could be increased by ozonation. The removal percentage of nitrogen precursors and organic carbon would be increased by BAC filtration.

Carbon Chemistry of Intact Versus Chronically Drained Peatlands in the Southeastern USA

AbstractThe Great Dismal Swamp National Wildlife Refuge (GDS) is a large temperate swamp in Virginia/North Carolina, USA with peat soils historically resistant to microbial decomposition. However, this peatland has been subject to ~200 years of disturbance during which extensive drainage, fire suppression, and widespread logging have increased decomposition and dramatically decreased the distribution of Atlantic white cedar (AWC). The purpose of this study was to determine the impact of long‐term drainage and AWC loss on the carbon chemistry of GDS peats. Peat cores were collected from three drained GDS vegetation communities (pocosin, AWC, and red maple‐black gum) and compared to cores collected from an intact, undrained AWC peatland at the Alligator River National Wildlife Refuge (AR) in North Carolina. The AR peats had higher lignin content in the deeper peat intervals, and lignin content and percent organic carbon were largely invariant with depth compared to the GDS peats. The concentrations of syringyl group phenols were greater in the surface layers of GDS peats, likely reflecting the selective removal of AWC and transition from gymnosperms to angiosperms. Acid to aldehyde ratios for vanillyl and syringyl group phenols indicated that the GDS peats were more decomposed, particularly at depth, and that this occurred under aerobic conditions. Moreover, solid‐state 13C NMR confirmed a coincident loss of carbohydrates and increase in recalcitrant by‐products of carbohydrate degradation with depth. These data indicate that long‐term drainage has accelerated the decomposition of peat at the GDS, reducing the capacity and stability of the carbon sink.

Spatiotemporal Variation of Abattoir Operation on Soil Quality Dynamics in Umuahia South, Abia State, Nigeria

Heaps of abattoir wastes are commonly sighted in most abattoirs in Nigeria which constitute serious environmental and public health hazards. The study aimed at assessing the spatiotemporal variation of abattoir operation on soil quality in Umuahia South, Abia State, Nigeria. A total of nine composite samples were collected from three different locations at graded distance. Conventional analytical methods were employed for the determination of physicochemical parameters. The results indicate that the mean pH value was 5.90, organic carbon 1.31% and 2.27% organic matter respectively. Mean values of 2.10 g/kg and 3.66 mg/kg were observed for total nitrogen and available phosphorus respectively. The exchangeable cations were observed to be 0.53Cmol/kg, 2.31Cmol/kg, 0.49Cmol/kg and 0.67Cmol/kg for Potassium, Sodium, Calcium and Magnesium respectively. The mean cation exchange capacity was 8.70Cmol/kg, mean percentage base saturation was 46.04% and mean of electrical conductivity was 5.96, Mean values of 5.06, 1.70%, 2.94%, 2.81g/kg, 5.28mg/kg, 0.63Cmol/kg, 3.17Cmol/kg, 0.50Cmol/kg, 0.51Cmol/kg, 8.64Cmol/kg and 55.29%, percentage organic carbon and organic matter, total nitrogen, available phosphorus, exchangeable potassium, sodium, calcium and magnesium, cation exchange capacity and percentage base saturation, electrical conductivity respectively. This study reveals that the possible source of contaminants is due to the unhygienic manner of handling meat in abattoirs and concludes that the results obtained indicated that the quality of the soil is negatively affected by the activities of the abattoir. Regular inspection of abattoirs and strict enforcement of law is hereby recommended.Keyword: Abattoir, Effluent, Pollution, Public health hazard

Distribution of Some Macro Nutrients and Chemical Properties in Some Semi-arid Soils of Borno State

The research was carried out to study the distribution of some macro nutrients and chemical Properties in some semi–arid soils of Borno state. Three composite soil samples were collected at different locations at depth of 0-20 cm which were analysed for some macro nutrients and chemical properties. University of Maiduguri (Unimaid) soil is slightly acidic to neutral in reaction, low in electrical conductivity (EC), high base saturation, low in percent organic carbon, moderate in calcium, high in magnesium, low in potassium, high in sodium, low in available phosphorus. Dalori soils were neutral in reaction, low in EC, high base saturation low in percent organic carbon, low in calcium, high in magnesium, low in potassium, high in sodium, low in available phosphorus. Gongulong soil was moderately acidic in reaction, moderate in EC, high base saturation, moderate in percent organic carbon, high in calcium, very high in magnesium, moderate in potassium, high in sodium, low in available phosphorus.

Depositional and post-depositional processes in human-modified cave contexts of west-central Patagonia (Southernmost South America)

This contribution aims to analyse depositional and post-depositional processes from two volcanic caves (Baño Nuevo 1 and Cueva de la Vieja) from west-central Patagonia, in order to evaluate if natural and anthropogenic processes recorded therein are representative of basin-scale processes. For this purpose, geomorphological, sedimentological, micromorphological, petrographic, magnetic, paleontological and archaeological data are integrated. Results allow correlating the Baño Nuevo 1 and Cueva de la Vieja sequences, comprising a record of ca. 19,000 years. In the first place, the distinction between endogenous and exogenous detritus input, mainly recorded by the mineralogy and lithotypes, provided environmental data related to landscape stability (i.e., vegetation cover). The latter, in turn, could be interpreted as part of a complex feedback associated with major climatic changes. On the other hand, cave weathering rates observed through vertical variations of the gravel fraction, along with bioactivity recorded by percentages of Total Organic Carbon and micromorphological analysis, provided constraints on temperature and/or humidity, being in agreement with available regional information. Main regional palaeoenvironmental changes observed in the sequences were the deglaciation processes, the Pleistocene-Holocene transition, the Holocene amelioration and the Anthropocene. Although no distinctive variations were observed within Holocene deposits, biological processes mainly resultant of the human occupations could have obliterated such finer scale distinctions.

Decomposition of environmentally persistent cyclic methylsiloxanes in subcritical water

The cyclic methylsiloxanes octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) were reacted in subcritical water at temperatures of 150–350 °C under argon, under O2, or in the presence of H2O2. When the reactions were performed in pure subcritical water (under argon) at 300 °C for 6 h, both D4 and D5 were almost completely hydrolyzed to water-soluble and hexane-non-extractable compounds such as dimethylsilanediol (DMSD). However, the high percentages of total organic carbon (TOC) remained in the aqueous phase [87% and 81% of the carbon atoms in the initial D5 (26.6 μmol) and D4 (30.6 μmol), respectively] and the low silicate yields (both 3% of the silicon atoms in the initial D5 and D4) indicated that little mineralization had occurred. Although the presence of O2 had no significant effect on the reactivity of these substrates in subcritical water at temperatures up to 300 °C, the presence of H2O2 enhanced the decomposition of these substrates. Raising the temperature to 350 °C greatly enhanced the mineralization. Specifically, when the reactions were performed in 2.0 M H2O2 for 2 h, the percentages of TOC that remained in the aqueous phase decreased markedly (to 2% and 10% of the carbon atoms in the initial D5 and D4, respectively) and IR spectral measurements indicated that most of the substrates had been oxidized to silicate.

Evidence for non-marine Jurassic to earliest Cretaceous sediments in the pre-breakup section of the Mentelle Basin, southwestern Australia

The Mentelle Basin, located off the southwestern continental Australian margin, is an under-explored deep-water basin that developed during the breakup of eastern Gondwana in the Middle Jurassic through to the Early Cretaceous. There is a high degree of uncertainty in stratigraphic interpretations of the basin owing to the lack of well and seismic data in the region. As a consequence, there has been a heavy reliance on data from the neighbouring Perth Basin to infer the geological history of the Mentelle Basin. During Expedition 369 of the International Ocean Discovery Program, a single hole was drilled with a rotary core bit to 517.10 m below seafloor at Site U1515 on the continental slope in the eastern Mentelle Basin. The aim was to sample and date the inferred Permian to Jurassic pre-breakup strata. The presence of palynomorphs including Murospora florida and Retitriletes watherooensis in the fluvio-lacustrine succession below the Valanginian breakup unconformity indicates a Jurassic to earliest Cretaceous age for the upper part of the pre-rift sedimentary succession. Notable characteristics of this succession include intervals with high percentages of total organic carbon (up to 44 wt%) and high hydrogen index values (Type I source rocks) associated with an increase in Botryococcus and other freshwater algae that accumulated in shallow lakes and waterlogged floodplains. A possible example of dinoturbation was also noted in this core. The discovery of Jurassic to earliest Cretaceous pre-breakup strata at Site U1515 suggests that Jurassic rifting was not constrained to the western depocentre of the Mentelle Basin, but also extended to a number of depocentres in the eastern Mentelle Basin. This has significant implications for the understanding of the regional tectonic history and the Mentelle Basin’s petroleum potential.Pre-breakup strata sampled in the eastern Mentelle Basin for the first time by IODP Expedition 369Upper Jurassic–Lower Cretaceous non-marine strata below the Valanginian UnconformityHigh TOC’s, high abundances of Botryococcus algae in a few horizons and a possible example of dinoturbationJurassic rifting not constrained to the western Mentelle Basin, but to depocentres in the east

Organic matter and properties of soil in forest and agriculture areas

Soil organic carbon (SOC) is one of the major components of soil. It includes plants, animals, and microbial residue in all stages of decomposition. SOC determines the quality, growth, and productivity of the soil. Different studies have shown that the amount of soil organic matter is found higher in forest land than in agricultural land. The study aims to quantify the amount of soil organic matter and also determine the other related soil properties of forest and agricultural land soils. Hence, the forest and agricultural land of Sandhikharka Municipality, Arghakhanchi is selected as the study area. The present research is based on random systematic sampling. The samples were collected from the forest and agricultural land. 10 samples were collected from each land use. The percentage of soil organic carbon was determined by Walkey and Black Method. For the calculation of soil, the organic matter percentage of soil organic carbon was multiplied by 1.724. Bulk Density was calculated by the core sampler method. The soil organic matter of forest land was found to be greater than agricultural land. Soil organic matter decreased with an increase in temperature. Bulk density was found higher in agricultural land soil than in forest soil. Bulk density shows a positive response to the increasing soil depth. Soil organic matter (SOM) is found higher in forest soil than in agricultural land and bulk density decreases with the increase in SOM.

SOME PHYSICAL AND CHEMICAL PROPERTIES OF SOIL AFFECTED BY THE APPLICATION OF DIFFERENT SOURCES OF LIME IN ABUJA, NIGERIA

A field experiment was conducted at University of Abuja Teaching and Research farm, F.C.T-Abuja, Nigeria to determine the effects of different sources of lime on soil properties. The experiment was laid out in a Randomized Complete Block Design (RCBD) in factorial fashion comprising six treatments replicated three times. The treatment includes two types of industrial lime (ultrasol - V1 and agricultural lime – V2) applied at three different levels. Data collected from the study were analyzed using Analysis of Variance (ANOVA) and means were separated with Duncan’s New Multiple Range Test (DNMRT). The result obtained showed a high significant effects of treatments on soil chemical properties. The soil chemical properties were calcium (Ca), with the application of V2L1 (1000kg/ha) giving the highest value relative to other treatments and control. Soil exchangeable magnesium showed a significant effect in the control plot (V2Lo). Percent organic carbon and percent organic matter content in the soil were highly significant in plots treated with V1L2 (ultrasol lime at 2000kg/ha). Exchangeable potassium (k) and sodium (Na) produced the highest values in plots amended with V1L1 (ultrasol lime at 1000kg/ha) though not significant. Base saturation was increased though not significant in V2L1 (agricultural lime at 1000kg/ha) treated plot. CEC (Cation Exchange Capacity) increased in the V2L0 (agricultural lime at 0kg/ha) but was not significant. Exchangeable acidity reduced greatly in V1L2 and V2L1 treated plots. Electrical conductivity in the soil and percent total nitrogen showed no significant difference but produced the highest values in plots amended with V1L1. Manganese (Mn) and copper (Cu) in the soil were influenced by treatments with the lowest values in plots treated with V2L2 (agricultural lime at 2000kg/ha) though not significant. Iron (Fe) was reduced in plot treated with V1L0 (ultrasol lime at 0kg/ha) but was not significantly different. Zinc (Zn) was completely eliminated on the application of both agricultural and ultrasol limes. Available phosphorus had no significant influence on the amended plots and control. Soil pH (in water (H2O), potassium chloride (KCl) and in calcium chloride (CaCl2) showed no significant effect on treatments and control. Based on the following results, the use of agricultural lime (V2­­) and ultrasol lime (V1)­ both at 1000kg/ha and 2000kg/ha could be recommended for improving soil properties.

Evaluating the Effects of Human Activity over the Last Decades on the Soil Organic Carbon Pool Using Satellite Imagery and GIS Techniques in the Nile Delta Area, Egypt

The study aims to clarify the relationship between soil organic carbon (SOC) and human activity under arid conditions, in the east area of the Nile Delta, Egypt. SOC is one of the critical factors in food production and plays an important role in the climate change because it affects the physio-chemical soil characteristics, plant growth, and contributes to sustainable development on global levels. For the purpose of our investigations, 120 soil samples (0–30 cm) were collected throughout different land uses and soil types of the study area. Multiple linear regressions (MLR) were used to investigate the spatiotemporal relationship of SOC, soil characteristics, and environmental factors. Remote sensing data acquired from Landsat 5 TM in July 1995 and operational land imager (OLI) in July 2018 were used to model SOC pool. The results revealed significant variations of soil organic carbon pool (SOCP) among different soil textures and land-uses. Soil with high clay content revealed an increase in the percentage of soil organic carbon, and had mean SOCP of 6.08 ± 1.91 Mg C ha−1, followed by clay loams and loamy soils. The higher values of SOCP were observed in the northern regions of the study area. The phenomenon is associated with the expansion of the human activity of initiating fish ponds that reflected higher values of SOC that were related to the organic additions used as nutrients for fish. Nevertheless, the SOC values decreased in southeast of the study area with the decrease of soil moisture contents and the increase in the heavy texture profiles. As a whole, our findings pointed out that the human factor has had a significant impact on the variation of soil organic carbon values in the Eastern Nile Delta from 1995 to 2018. As land use changes from agricultural activity to fish ponds, the SOCP significantly increased. The agriculture land-use revealed higher SOCP with 60.77 Mg C ha−1 in clay soils followed by fish ponds with 53.43 Mg C ha−1. The results also showed a decrease in SOCP values due to an increasing in land surface temperature (LST) thus highlighting that influence of temperature and ambient soil conditions linked to land-use changes have a marked impact on surface SOCP and C sequestration.