Soil Classification Research Articles

Nest-site selection of Eurasian Curlew (Numenius arquata) in the centre of its European range: adaptation to local macrohabitat factors

AbstractThe most important cause of the declining numbers of wading birds is a combination of habitat loss and degradation, as well as low productivity due to predation. Knowledge of the habitat requirements of this endangered group of species is critical for maintaining and restoring suitable breeding habitats. The aim of this paper is to characterize those habitat components of the Eurasian Curlew (Numenius arquata) which determine its choice of nesting site. This study was undertaken in three sites in Poland, the most important breeding areas of this species in this country. Our results showed that macrohabitat factors affect curlew nest-site selection in different ways. The most important ones were distance to a forest edge, the percentage cover of managed farmland in the vicinity and the number of farmland plots close to the nest. Other habitat components, such as distance to scattered trees, distance to roads and soil category, were of lesser importance and could be treated as localized. This study is a contribution to the knowledge of the Eurasian Curlew’s nest-site selection in farmland grasslands, which may have implications for its conservation.

Carbon stocks in Planosols along a rainfall gradient in Northeast Brazil

Planosols have sandy-textured surface horizons that abruptly cover a dense subsoil with high clay content, which usually limits drainage and influences soil moisture. Here, we investigated changes in C storage through the pedogenic horizons of soil profile, including detailed sampling of A and B horizons along a transect to cover rainfall variation (584–1130 mm year−1) and soil cover of Planosols, including dry land areas in Northeast Brazil. The soil profile located under highest precipitation and with the greatest pedogenic development (150 cm) showed the largest C stock (101.91 Mg/ha), surpassing estimates of other soil classes. In addition, our results suggest that soil cover and pedogenesis impact C storage in Planosols. An average of 64 % of C is stored in subsurface horizons that present abundant clay fraction; thus, the dynamics of subsurface soil organic carbon (SOC) appear to be more controlled by soil features than by climate. Values of δ13C indicated the predominance of C3 plant, except in area with sugarcane cultivation (C4 plant). Changes in C distribution within the horizon suggest changes in degree of decomposability of soil organic matter (SOM), mainly in A1 and B1 layers, with A horizon richer in labile compounds. δ15N values indicated that N dynamics differ in the gradient. The thermal analyses showed that around 70 % or more of humin fraction is composed of structures more resistant to degradation, suggesting that C stock in Planosols has relative stability. However, in driest part of the climate transect, SOM may be more vulnerable to losses due to the large relative quantity of aliphatic groups in soil surface and subsurface. This work provides insights into the mechanisms the determine C storage distribution in tropical Planosols and contributes to appropriate use and management of these soils to ensure the valuable ecosystem service of C storage.

Derajat Kepadatan Lapis Pondasi Agregat Tanpa Penutup Aspal Menggunakan Metode Sand Cone pada Proyek Rekonstruksi Jalan Kecamatan Serai Serumpun, Kabupaten Tebo di Ruas Jalan Tanjung Aur Seberang-Malako Tinggi

Road infrastructure is very important for the economic progress of Tanjung Aur Seberang village residents. Economic development in Tanjung Aur Village, Tebo Regency has significantly increased traffic levels. If this is not balanced by improving the quality of transportation facilities and infrastructure, then this could cause serious problems. Determining the value of the degree of density of the foundation layer aggregate (soil) class S in obtaining soil stability with safe conditions in accordance with the requirements of density standards is the aim of this research. The methods used are direct tests in the field and in the laboratory. Testing soil density in the field using a sand cone tool follows the provision stated in SNI 03-2828-1992, while testing soil density in the laboratory follows the provisions stated in SNI 1742-2008. Soil density testing intervals vary between 50 meters, 75 meters, 100 meters, 150 meters, 200 meters depending on location conditions. The results sand cone testing was carried out on roads from STA 2+000 to 3+800. In the first test with 9 test points, the field density was obtained below 95%, namely STA 2+100 (94,141%), STA 2 +550 (94,389%) and STA 3 +800 (94,289). Theses results indicate that the required standard degree of field density has not been achieved, so that the base layer of class S aggregate can be added and compaction can be carried out again. And from STA 0 + 005 to 4 + 200 in the second test with 26 test points. Test results using a sand cone tool show that the average water content value is 7.513% with a density reaching 98.846%. and these results were in accordance with applicable standard requirements.

Assessment of Land Capability and Zoning for Sustainable Urban Development in Ambon City

The optimization strategy replaces ability-useful land with conservation-source power land, which may help with problem degradation. Investigate this to determine the level of land ability and the function area designation for good protection and cultivation in the Satuan Wilayah Pengembangan (SWP). The research method is descriptive and quantitative, with stepwise data collection and processing. Data collection is carried out through studies and literature from several agencies. Temporary spatial data analysis was conducted using Geographic Information System (GIS) software. The research findings underscore a significant aspect regarding land analysis, specifically about allocating areas for settlement purposes. The documented 3687.35 hectares identified as suitable for settlement development, alongside the approximately 11755.27 hectares allocated as buffer zones, highlight a limited portion of land deemed suitable for urban expansion within the studied region. This observation underscores the challenge of finding suitable and adequate spaces for urban development initiatives in Ambon City. Identifying such a confined area underscores the need for strategic urban planning that considers land constraints, such as the predominantly hilly terrain, to ensure balanced development, efficient land use, and the preservation of environmental integrity. Efforts toward optimizing these available areas for urban growth while concurrently focusing on conservation and ecological sustainability become imperative for Ambon City's future urban development trajectory. They created a barrier to physical land where hilly areas dominate the characteristics of the Ambon City area

Soil Development and Land Suitability for Cacao on Sandstone and Pumice Breccia in the Semilir Formation in Ponjong District, Gunungkidul Regency, Indonesia

The parent material of the Semilir Formation, which consists of breccia pumice and sandstone, was located in the villages of Sawahan and Umbulrejo, Ponjong district, and it influences the genesis and soil types. This study utilized survey and laboratory analysis methods. Two soil profiles were studied: the first profile was located in Sawahan Village with breccia pumice as the parent material, while the second profile was in Umbulrejo Village with sandstone as the parent material. The research results indicated that soils developed from breccia pumice had diagnostic horizons of umbric epipedon and argillic endopedon with an advanced soil development stage. Soils developed from sandstone had diagnostic horizons of umbric epipedon and cambic endopedon with a young soil development stage. This affects the chemical properties of the soil. Soils formed from pumice breccia tend to have base saturation of less than 50% with low exchangeable bases, while soils formed from sandstone have base saturation of >50% with high exchangeable bases. Soils developed from breccia pumice and sandstone have soil classification as Typic Paleudults and Typic Dystrudepts. These soil types are suitable for cocoa plant cultivation; however, they require mechanical conservation through terrace construction and improved drainage by incorporating organic materials or compost into the soil, which can significantly enhance soil porosity, enabling better water retention and drainage.

Soil Development and Land Suitability for Cacao on Sandstone and Pumice Breccia in the Semilir Formation in Ponjong District, Gunungkidul Regency, Indonesia

The parent material of the Semilir Formation, which consists of breccia pumice and sandstone, was located in the villages of Sawahan and Umbulrejo, Ponjong district, and it influences the genesis and soil types. This study utilized survey and laboratory analysis methods. Two soil profiles were studied: the first profile was located in Sawahan Village with breccia pumice as the parent material, while the second profile was in Umbulrejo Village with sandstone as the parent material. The research results indicated that soils developed from breccia pumice had diagnostic horizons of umbric epipedon and argillic endopedon with an advanced soil development stage. Soils developed from sandstone had diagnostic horizons of umbric epipedon and cambic endopedon with a young soil development stage. This affects the chemical properties of the soil. Soils formed from pumice breccia tend to have base saturation of less than 50% with low exchangeable bases, while soils formed from sandstone have base saturation of >50% with high exchangeable bases. Soils developed from breccia pumice and sandstone have soil classification as Typic Paleudults and Typic Dystrudepts. These soil types are suitable for cocoa plant cultivation; however, they require mechanical conservation through terrace construction and improved drainage by incorporating organic materials or compost into the soil, which can significantly enhance soil porosity, enabling better water retention and drainage.

Machine Learning-Based Classification of Soil Parent Materials Using Elemental Concentration and Vis-NIR Data.

In soil science, the allocation of soil samples to their respective origins holds paramount significance, as it serves as a crucial investigative tool. In recent times, with the increasing use of proximal sensing and advancements in machine-learning techniques, new approaches have accompanied these developments, enhancing the effectiveness of soil utilization in soil science. This study investigates soil classification based on four parent materials. For this purpose, a total of 59 soil samples were collected from 12 profiles and the vicinity of each profile at a depth of 0-30 cm. Surface soil samples were analyzed for elemental concentrations using X-Ray fluorescence (XRF) and inductively coupled plasma-optical emission spectrometry (ICP-OES) and soil spectra using a visible near-infrared (Vis-NIR) spectrometer. Soil samples collected from soil profiles (12 soil samples) and surface (47 soil samples) were used to classify parent materials using machine learning-based algorithms such as Support Vector Machine (SVM), Ensemble Subspace k-Near Neighbor (ESKNN), and Ensemble Bagged Trees (EBTs). Additionally, as a validation of the classification techniques, the dataset was subjected to five-fold cross-validation and independent sample set splitting (80% calibration and 20% validation). Evaluation metrics such as accuracy, F score, and G mean were used to evaluate prediction performance. Depending on the dataset and algorithm used, the classification success rates varied between 70% and 100%. Overall, the ESKNN (99%) produced better results than other classification methods. Additionally, Relief algorithms were employed to identify key variables for each dataset (ICP-OES: CaO, Fe2O3, Al2O3, MgO, and MnO; XRF: SiO2, CaO, Fe2O3, Al2O, and MnO; Vis-NIR: 567, 571, 572, 573, and 574 nm). Subsequent soil reclassification using these reduced variables revealed reduced accuracies using Vis-NIR data, with ESKNN still yielding the best results.

Identification of high-performing soil groups in grazing lands using a multivariate analysis method

Understanding and quantifying the complex relationships between soil properties and vegetation health is important for sustainable land management and optimising agricultural productivity. This study tested a spatial data-driven framework to identify the soil groups associated with pasture health using publicly available gridded soil attribute layers from Soil and Landscape Grid of Australia (SLGA) over two adjacent southeast Australian river catchments. Principal component analysis (PCA) followed by isocluster unsupervised classification was applied to seventeen SLGA soil attribute layers to identify dominant soil patterns, which showed good spatial agreement with the Enhanced Vegetation Index (EVI) data derived from Landsat-8 imagery. The soil class demonstrating the highest EVI values (HVR class) and the lowest EVI values (LVR class) were determined. A comparison of these classes with soil types defined in the New South Wales Soil Landscape maps confirmed that the HVR class is predominated by agriculturally productive, basalt-derived 'Ant Hill' soils. The cation exchange capacity (CEC) ranging from ∼10 to 20 meq/100 g, clay content ranging from 20 % to 30 %, pHc (pH in calcium chloride solution) between 5 and 6, pHw (pH in water) between 5.5 and 6.5 and SOC between 2.5 % to 4 % were associated with higher EVI values in the HVR soil class within the study area. This study demonstrated an effective framework for identifying key soil attributes that affect agricultural productivity and pinpointing critical locations for grazing land productivity.

Characterization and Classification of Desert Depressions Soils in Najaf Province

Characterization and Classification of Desert Depressions Soils in Najaf Province

Expansive clay subgrade soil improvement using municipal solid waste fly ash: Experimental and numerical approach

The expansive soil under investigation has caused damage to lightweight structures due to its swelling and shrinkage characteristics in response to changing moisture content. The study aims to assess the impact of municipal solid waste (MSW) fly ash on the engineering properties of subgrade expansive soils and its influence on pavement structure deformation. The influence of municipal solid waste fly ash on expansive soils was evaluated using laboratory tests and finite element methods. The Abaqus software was used to investigate the effects of MSW fly ash on pavement structure deformation. The input parameters employed for this analysis were elastic modulus, Poisson ratio, load, contact area dimension, and pavement layer thickness. To mitigate this issue, MSW fly ash was used as a stabilizing agent at varying percentages (5 %, 10 %, 15 %, 20 %, 25 %, and 30 % of the dry mass of the soil sample).According to the AASHTO soil classification, the soil is classified as A-7, has a high free swell, a low soaked CBR value, and a high soaked CBR swell, and does not meet the ERA manual standard for subgrade materials. The laboratory tests shown several improvements in the engineering properties of expansive soil when MSW fly ash were mixed. These improvements included a reduction of soaked CBR swelling, free swell index, plasticity index, specific gravity, optimum moisture content. Additionally, the maximum dry density and soaked CBR values increased. Numerical analysis using Abaqus software focused on vertical deformation of the pavement structure. The results showed that as the percentage of MSW fly ash in form 0 % to 25 % of soil dry weight, the vertical deformation of the pavement structure decreased from 0.84 mm to 0.67 mm. This demonstrates that the addition of MSW fly ash reduced the deformation of expansive sub-grade soil and improved the engineering qualities of pavement structure. In conclusion, the study revealed that the use of MSW fly ash as stabilizing agent effectively reduced the deformation of expansive subgrade soil and improved the engineering qualities of pavement structure.

Site-Specific Seismic Hazard Analysis for Shallow Tunnel in Nepal

Abstract Several seismic codes are implemented for the design and construction of superstructures in Nepal but there is no seismic guideline for shallow tunnels which are often constructed using conventional engineering approaches. The uniform hazard spectrum was obtained after performing a Probabilistic Seismic Hazard Analysis at Dhulikhel and the target spectrum was estimated by comparing it with the spectrum recommended by the seismic code of Nepal Building Code NBC 105:2020 and Indian standard IS 1893:2016. The average response spectrum from ten recorded earthquake ground motions was selected from a peer ground motion database with the known shear wave velocity obtained from geophysical survey. The comparative analysis revealed that the design spectra for identical soil classes, as determined by this study are slightly higher than those prescribed by the present seismic code provisions. This finding emphasizes the necessity for developing more specific guidelines tailored to the design of shallow tunnels in Nepal to ensure their structural resilience in the event of an earthquake.

Assessing the Impact of Clearing and Grazing on Fuel Management in a Mediterranean Oak Forest through Unmanned Aerial Vehicle Multispectral Data

Climate change has intensified the need for robust fire prevention strategies. Sustainable forest fuel management is crucial in mitigating the occurrence and rapid spread of forest fires. This study assessed the impact of vegetation clearing and/or grazing over a three-year period in the herbaceous and shrub parts of a Mediterranean oak forest. Using high-resolution multispectral data from an unmanned aerial vehicle (UAV), four flight surveys were conducted from 2019 (pre- and post-clearing) to 2021. These data were used to evaluate different scenarios: combined vegetation clearing and grazing, the individual application of each method, and a control scenario that was neither cleared nor purposely grazed. The UAV data allowed for the detailed monitoring of vegetation dynamics, enabling the classification into arboreal, shrubs, herbaceous, and soil categories. Grazing pressure was estimated through GPS collars on the sheep flock. Additionally, a good correlation (r = 0.91) was observed between UAV-derived vegetation volume estimates and field measurements. These practices proved to be efficient in fuel management, with cleared and grazed areas showing a lower vegetation regrowth, followed by areas only subjected to vegetation clearing. On the other hand, areas not subjected to any of these treatments presented rapid vegetation growth.

A new approach for identification of dispersivity class of soils by combining physical and chemical tests

The safety and performance of embankment dams after impounding water are highly related to the characteristics of the selected dam material. Impermeability is achieved by using clay soils as the core material in embankment dams. It has been observed that there are many collapsed dams, especially when dispersive soils with very low internal erosion resistance are used in the impermeable zone. For this reason, such soils should be determined at the design stage and not used in the construction of embankment dams. The dispersion mechanism is known to be controlled by clay mineralogy and cations in the pore fluid of soil. The physicochemical behaviour of the clay-water system is crucial to clarify the dispersion mechanism. Physical and chemical tests used for determining the dispersibility potential of soils are extensive and time-consuming methods. An alternative method has been proposed within the scope of this study. Three user-friendly and practical models based on Gene Expression Programming (GEP) were produced using chemical and double hydrometer test results to predict dispersion percentage (D%). In addition, a new classification criteria was proposed to identification of dispersivity class based on pinhole test data. If the dispersion percentage is less than 12% is soil is classified as non-dispersive, the dispersion percentage is between 12% and 30% and greater than 30%, it is defined as intermediate and dispersive, respectively. With this proposed criterion, more consistent and successful results were obtained for the dispersivity class.

Application of industrial by-product waste as soil stabilising backfill material using a multi-layering method

Peat soil presents significant challenges for construction due to its inherent weak properties, including high water content, limited permeability, low shear Strength, low specific gravity, and acidity. Despite the potential of Mg-rich synthetic gypsum (MRSG) to improve soil properties, research on its use for stabilising severely poor peat soils is limited. This study addresses this gap by investigating the efficacy of MRSG in peat soil stabilisation using a novel multi-layering backfill approach. The methodology includes soil classification of peat soil. And, to understand the mechanical and chemical changes of stabilized peat soil, the unconfined compressive Strength (UCS) testing and microstructural analysis using SEM, EDX, and XRD before and after stabilisation are studied. Peat samples were treated with MRSG through backfilling method in 5, 7, and 9 layers and evaluated the strength increment after curing periods of 7, 28, and 60 days. Results demonstrate that MRSG significantly enhanced the compressive strength, increasing it to 210.33 kPa as early as 7 days for 9 layers of backfill incomparable with the untreated soil strength of 51.87 kPa. The new cementitious product in the soil known as ettringite was observed from SEM analysis and confirmed by the EDX and XRD analysis. By recycling industrial byproducts, this environmentally friendly method encourages sustainability and lessens dependency on raw resources, which is important for infrastructure construction and other projects in areas rich in peat.

Characterization, Classification and Suitability Evaluation of Soils in Ukum, Benue State, Nigeria for Maize and Yam Production

Characterization, Classification and Suitability Evaluation of Soils in Ukum, Benue State, Nigeria for Maize and Yam Production

Aero-propulsive coupling modeling and dynamic stability analysis of distributed electric propulsion tandem-wing UAV with rapid ascent capability

The distributed electric propulsion tandem-wing unmanned aerial vehicle (UAV) offers higher aerodynamic efficiency than conventional electric vertical takeoff and landing UAV and superior rapid ascent takeoff and landing capabilities compared to regular fixed-wing aircraft. However, for this configuration, the aero-propulsive coupling effects between the propellers and wings are significant. To study the mutual interaction between distributed electric propulsion and aerodynamics on the flight dynamics characteristics and rapid ascent flight capability of UAV, an aero-propulsive coupling model incorporating the effects of propellers slipstream is established. Ground-based blown wing experiment is conducted to validate the modeling accuracy. Subsequently, a theoretical modeling framework based on standard stability derivatives is developed, incorporating the influence of thrust on the dynamics within stability derivatives. The dynamic characteristics of distributed electric propulsion tandem-wing configuration are then studied and aero-propulsive coupling effects on natural modes of motion and flight qualities are analyzed. Finally, flight simulations and actual flight tests are conducted to validate the rapid ascent flight capability of UAV in real-world. The experimental results indicate that UAV can achieve rapid ascent flight with significant pitch angles and high climb rates, showing promising results with more than a 91.9% improvement in takeoff performance compared to conventional rolling takeoff.

Automatic soil classification method from CPTU data based on convolutional neural networks

Automatic soil classification method from CPTU data based on convolutional neural networks

Soil‐vegetation interplay in a Holocene toposequence at Torres del Paine National Park, southern Andes, Chile

AbstractChile's Torres del Paine National Park (TPNP) is one of the most impressive landscapes in southern Patagonia, with unique natural elements on the edge of the southern ice field, where knowledge of soils and ecological relationships is nonexistent. Therefore, the objective of this study was to determine the chemical, physical, mineralogical, and micromorphological characteristics of Holocene soils along a local toposequence representing the main vegetation types of the TPNP. The morphological, chemical, physical, and mineralogical properties of 12 soil profiles were studied and classified according to Soil Taxonomy. Coevolution of vegetation and soil taxa is clearly evident since glaciation, with podsolization under austral Nothofagus pumilio forests leading to the development of spodosols, while paludization in local depressions with Nothofagus forests allowed the formation of histosols. Slopes covered with loess and tephra led to the formation of Andisols with shrub vegetation. Predominant parent materials include till from Late Quaternary advances of southern Andean ice, Pleistocene loess, and volcanic ash from surrounding Chilean volcanoes. The parent materials were strongly influenced by Late Quaternary climatic and landscape changes following the retreat of the Last Glacial Maximum in southern Patagonia, resulting in erosional and depositional conditions (windblown loess, fluvial glacial deposits, and moraines). Stable landforms show the influence of allochthonous volcanic ash shaping Andean features, combined with the accumulation of organic matter in hydromorphic soils. Three main groups of soils have been identified: loess‐rich soils, organic‐rich soils, and poorly developed soils. The latter show low fertility related to recent landforms on different substrates ranging from till, rocky slopes, talus, or glacial deposits. In high mountain regions under periglacial conditions, cryoturbation features indicate seasonal frost–thaw cycles without current permafrost. The diversity of soil orders in the mountains of southern Patagonia is comparable to similar environmental conditions and latitudes in the Northern Hemisphere. However, the andic properties due to volcanic ejecta inputs, as well as organic‐rich soils at low altitudes of bottom valleys, are typical features of the soils at TNTP.

Morphological and Physico-chemical Properties of Soils of Amtur-3 Micro-Watershed on Schistose Landscape in Bailhongal taluk of Belagavi District, Karnataka, India

Aims: To assess the morphological and physico-chemical properties of two soil series viz., KKT (Kabulayathkatti tanda) and SDH (Singadahalli) of Amtur-3 micro-watershed developed on schistose landscape in northern transition zone of Karnataka. Place and Duration of Study: The study was carried out in the Amtur-3 micro-watershed (4D5B8t04) located in Bailhongal taluk of Belagavi district, Karnataka during 2022-2024. Methodology: Horizon-wise soil samples were collected from the two representative pedons viz., KKT (Kabulayathkatti tanda) and SDH (Singadahalli) soil series, were identified, characterized and classified up to family level according to revisions in Soil Taxonomy using morphological, physical and chemical properties. Results: The soils of these two series were sandy clay loam to clay in texture, neutral in soil reaction and had low salt content. Calcium and magnesium were the dominant cations followed by sodium and potassium. Both the soil series belonged to the order Inceptisol.

Assessment and development of empirical correlations between flat plate dilatometer and cone penetration tests for Auckland soils

ABSTRACT Based on a database of over 2900 cone penetration test (CPT) and flat plate dilatometer test (DMT) data pairs obtained from Auckland, New Zealand, this paper assesses the applicability of several empirical CPT-DMT correlations and presents newly developed regional correlations for use in geotechnical engineering applications. Empirical correlations using the DMT-based material index are assessed. As both the DMT-based material index (ID ) and the soil behaviour type index (Ic ) from CPT data are often used to estimate soil behaviour characteristics when no samples are retrieved, these were used to develop subset databases. In general, the correlation used to estimate the material index (ID ) tended to slightly overestimate the measured values for Auckland soils, while better performance could be observed after removing data points where Ic and ID soil classifications were incompatible. In contrast, the correlations used to estimate horizontal stress index (KD ), and dilatometer modulus (ED ) underestimated the measured values for the database used herein, with the largest underestimates for low cone tip resistance values. This paper presents new correlations for estimating KD and ED based on CPT parameters for Auckland soils, providing improved estimates, with stable bias values across the range of input parameters considered.