Percentage Of Sand Research Articles

ASSESSMENT OF THE PHYSICOCHEMICAL PROPERTIES OF SOIL IN FARMLANDS OF BIRNIN YERO, IGABI LOCAL GOVERNMENT AREA, KADUNA STATE, NIGERIA

Globally, soil degradation is widely recognized as a major agricultural and environmental problem. This study assess the physicochemical properties of soil in farmlands in Birnin Yero, Igabi LGA, Kaduna State. Soil samples were collected from different farmlands and analyzed for particle size (sand, silt, and clay), pH, Organic Carbon (OC), Organic Matter (OM), Exchangeable Acidity (EA), Available phosphate (AP), Calcium (Ca), Magnesium (Mg), Potassium (K), and Sodium (Na). The study revealed that soils of the study area are sandy loam and loamy and the acidic pH indicates the need for soil amendments to improve nutrient availability for plant growth. The medium to low levels of OC, OM, and AP highlight the significance of using soil amendments and focused fertilization techniques to improve soil fertility. Correlations between physicochemical properties demonstrated interrelationships, where EA showed a negative correlation with pH, Mg showed a positive correlation with pH and a negative correlation with EA. K showed a positive correlation with AP and EA. Na showed a positive correlation with Ca. OM had a positive correlation with OM. The percentage of sand in the soils had a negative correlation with OC and OM. Silt soils correlated positively with OC. Then clay soils had a positive correlation with OC and OM. It was concluded that soils from the study area can impact water drainage, nutrient retention, and soil fertility. Furthermore, the physicochemical properties indicate that soil amendments and targeted fertilization strategies should be employed to enhance soil fertility.

Estimation of dynamic soil properties for geotechnical analysis in the Niger Delta using index testing and empirical correlations

This study investigated geotechnical properties of subsurface soils from Mbiama town in Rivers State, Niger Delta region through laboratory index testing and development of empirical correlations to estimate dynamic soil parameters. Grain size analyses revealed heterogeneous stratigraphy transitioning from upper clayey sands to lower gravelly sands deposited under changing fluvio-deltaic conditions. Atterberg limits exhibited decreasing plasticity trends with depth confirming the textural variations. Laboratory data conforms to layering architecture inferred from depositional facies analyses. Predictive models were developed relating Standard Penetration Test blow counts (SPT-N) and shear wave velocity (Vs) to depth, moisture content and percentage sand. High regression coefficients validated models' accuracy in reproducing over 90% of field measurements. Factor of safety against liquefaction was correlated to SPT-N, accounting for density-dependent properties. Index-based characterizations aligned well with trends predicted by the empirical correlations. This research demonstrated robust indirect estimation of dynamic geotechnical indices for foundation design and seismic risk analysis in data-scarce Niger Delta through standardized field and laboratory index testing integrated with depositionally-linked predictive models.

Optimized Photocatalytic Degradation of Methylene Blue Using Titaniferous Sand/ZnO Composite: A Sustainable Approach to Wastewater Treatment

This study explores a novel approach to enhancing photocatalytic efficiency by utilizing an industrial residue, titaniferous sand, in combination with ZnO. The purifying efficiency of this semiconductor mixture was studied for the removal of methylene blue in a fixed-bed reactor. The main objective was to find out with what percentage the titaniferous sand could be incorporated into the ZnO for maximum photocatalytic performance. Box-Behnken Design (BBD) in the Response Surface Methodology (RSM) was used to optimize the operative parameters. The influence of titaniferous sand/ZnO ratio (A:1-2.8), pH (B:4-10) and irradiation time (C:120-480 minutes) on the degradation efficiency of the dye was studied. Initial concentrations of methyl blue and total semiconductor mixture were set at 25 mg/L and 10 g/L, respectively. The ANOVA analysis showed that the photocatalytic process was significantly affected by a positive individual effect of the titaniferous sand/ZnO ratio and the irradiation time. A quadratic polynomial of the second order accurately represented the experimental values with a correlation coefficient R2 of 0.9921. In addition, this model had a p-value of less than 0.0001 and an F-value of 84.09. Thus, the model used was quite appropriate. Optimal conditions were obtained for a ratio (titaniferous sand/ZnO) of 1.51057, i.e. a titaniferous sand percentage of 66%, a pH of 9.97487 and an irradiation time of 479.765 minutes. Under these conditions, a degradation of 99.4915% was obtained. In addition, the photocatalytic degradation kinetics of methylene blue on the titaniferous sand and ZnO mixture followed the Langmuir-Hinshelwood model and was of the first order with an apparent kinetic constant of 0.402 h-1.

Development of a Model for Quantifying Erodibility of Soils in Eastern Nigeria

Erodibility is the most variable factor influencing water-induced gully erosion in soil, as it governs the soil's susceptibility to detachment by opposing the driving force of rainfall erosivity in the gully erosion process. Previous studies on erodibility in Eastern Nigeria have been conducted segmented, lacking a unified model for its quantification. Therefore, this study investigated erodibility and developed a model to quantify it in the region. The nine areas most at risk for gully erosion, one in each of the region’s nine constituent states, were purposively sampled, with one gully from each area then selected through convenient sampling. Data collection instruments included observation, satellite imagery, and experimentation. A total of 81 soil samples—9 from each gully—were collected at depths of 0–30 cm, 30–60 cm, and 60–90 cm to determine the percentages of sand, silt, and clay used to quantify erodibility via Bouyoucos’ Model. Multiple Linear Regression was employed for data analysis. Results indicated that the independent variables (%sand, %silt, and %clay) made significant contributions to the dependent variable (clay ratio/erodibility) across the gullies. Ten models were developed, one for each gully and one general model for the region, as the independent variables made a significant combined contribution (R = .47, R² = .22, p = 0.00 < 0.05 significance level) to the dependent variable. The regression equation produced a model for quantifying erodibility in Eastern Nigeria as follows: erodibility (clay ratio) = 129.04 – 179 sand – 2.237 silt – 9.189 clay. The study recommends: (i) prioritizing the quantification of erodibility in all gully erosion studies to enable the application of appropriate gully remediation strategies, and (ii) the use of the developed erodibility model by built environment professionals in approving development initiatives, among other applications.

Soil Physical Properties Affect Herbivory of Lampronadata cristata in a Cork Oak Forest.

Studies have reported the important role of soil properties in regulating insect herbivory under controlled conditions or at relatively large scales. However, whether fine-scale variation of soil properties affects insect herbivory under natural conditions in forests is still unclear. We selected a ca. 300 ha Quercus variabilis forest area where the leaf damage was mainly caused by Lampronadata cristata (Lepidoptera: Notodontidae) and set 200 10 × 10 m plots within the area. We examined insect herbivory (percent leaf area damaged) on Q. variabilis and correlated it to soil properties and tree characteristics. Insect herbivory decreased with soil sand percentage and bulk density and increased with DBH and tree height. Effects of soil sand percentage and bulk density on insect herbivory were partly mediated by DBH and tree height. Our results indicated that soil physical properties may have significant effects on insect herbivory by directly influencing insect herbivores that need to complete their life cycle in the soil, or by indirectly affecting insect herbivores through influencing DBH and tree height which reflects the total leaf biomass available to the insect herbivore. This study may help to understand the complex relationship between soil and plant-insect interactions in forest ecosystems.

Plant-Parasitic and Free-Living Nematode Community Associated with Oak Tree of Magoebaskloof Mountains, Limpopo Province, South Africa

A study was conducted in the mountains of Magoebaskloof, Limpopo Province, where oak trees grow along the banks of the Broederstroom River. This study revealed that 22 nematode genera were associated with oak trees (Quercus robur). The most frequently occurring nematodes were Aphelenchus sp. (100%) and Plectus sp. (100%), followed by Helicotylenchus sp. (90%). This study examined the relationship between nematodes and the physicochemical properties of the soil using Pearson correlation. It uncovered that the organic matter content (OMC) had a negative correlation with the number of Panagrolaimus sp. (r = −0.770) and Hemicycliophora sp. (r = −0.674). Conversely, the sand percentage positively correlated (r = 0.695) with the number of Hemicycliophora sp. The clay content of the soil showed a positive correlation (r = 0.617) with the number of Ditylenchus. Soil pH demonstrated a significant negative correlation with Acrobeloides sp. (r = −0.877). The canonical correspondence analysis (CCA) explained 63.3% of the relationship between nematodes and soil physicochemical properties. The CCA results indicated that Ditylenchus exhibited a positive correlation with OMC, while the Panagrolaimus and Hemicycliophora species showed a negative correlation with OMC. The results indicated that none of the soil sample sites were under stress. The soil food web analysis revealed that most soil samples were nutrient-enriched with a low C/N ratio. In conclusion, this study revealed that oak trees harbor a high diversity of plant-parasitic and free-living nematodes. The results suggest that soil nematodes, particularly free-living bacterivores, such as Panagrolaimus, can indicate organic matter content in the soil.

The Aftermath Of Diapers Absorbents On Soil PhysioChemical Properties And Its Influence On The Performance Of Crops (Maize) Yield In Obubra Local Government Area Of Cross River State, Nigeria

This study investigates the environmental impacts of disposable diaper absorbents on soil physico-chemical properties and their subsequent effects on maize (Zea mays L.) yield in Obubra Local Government Area, Cross River State, Nigeria. The increasing use of disposable diapers, particularly in regions with inadequate waste management, poses significant challenges to soil health due to the non-biodegradable nature of superabsorbent polymers (SAPs) and other materials contained within these products. We conducted a controlled experiment on sandy soil, analyzing various treatments with different levels of diaper absorbents (0g, 40g, 80g, 120g, 160g, and 200g per 10kg of soil). Soil samples were collected and subjected to standard physico-chemical analyses, including texture, pH, organic matter content, and nutrient availability. Our findings reveal that moderate levels of diaper absorbents can maintain beneficial sand content while increasing silt levels, which may enhance soil fertility and moisture retention. However, excessive application (beyond 80g) leads to diminished sand percentages and potential long-term soil health issues, such as reduced aeration and root growth inhibition. The pH of the soil across treatments ranged from 6.26 to 6.88, indicating a generally favorable environment for maize cultivation. This research highlights the need for sustainable waste management strategies to mitigate the adverse effects of disposable diaper waste on agricultural land. By providing insights into the complex interactions between diaper absorbents and soil properties, our findings contribute to the broader discourse on agricultural sustainability and environmental health in developing regions. Further studies are recommended to explore the long-term ecological implications of diaper absorbents in agricultural contexts

Industrial Assessment of Mudstone Deposits of Gercus Formation as a Raw Material for Bricks Industry in Erbil Governorate, Northern Iraq

This paper evaluates the mudstone deposits' physical, chemical, and mineralogical properties and the possibility of use as a raw material to manufacture building bricks. Four sites are selected from the Gercus Formation in Shaqlawa district and the samples are tested. The mudstone samples are analyzed to define the grain size, Atterberg limits, chemical, physical and mechanical characteristics of the clay bricks. The grain size analysis of the mudstone samples showed they contained a high percentage of clay and silt and a low percentage of sand. The chemical analysis showed that silica (SiO2) was the major component in the mudstones. XRD analysis showed the presence of non-clay minerals i.e. calcite, quartz, albite and clay minerals of illite, palygorskite and chlorite. Raw samples of all studied sites were treated to prepare brick samples without addition, and others with 10% standard sand added. The results showed that the bricks prepared from the B to B10 and C to C10 stations have varying water absorption and compressive strength, while the efflorescence has light salts. All these properties are within the requirements of the Iraqi specification for brick manufacturing. The sample sites A, D, A10, and D10 are not compatible with the Iraqi standard in terms of absorption and compression.

Analisis Pengaruh Pasir Pantai Wahede Kabupaten Barru Terhadap Kuat Tekan Dan Tarik Belah Beton

Barru Regency is a coastal area with abundant potential for Wahede beach sand, which can be used to make economical concrete. This research aims to determine the compressive and tensile strength values of concrete as well as the optimal percentage of the beach sand mixture. The research was carried out at the Structure and Materials Laboratory of the Muhammadiyah University of Parepare, with a planned compressive strength of 20 MPa.The results of research on normal concrete compressive strength at 7 days were 12.27 MPa, 14 days 13.97 MPa, and 28 days 20.29 MPa. Variation: 25%; compressive strength: 7 days 13.58 MPa, 14 days 15.85 MPa, and 28 days 21.89 MPa. Variation 50%, compressive strength 7 days 14.34 MPa, 14 days 18.68 MPa, and 28 days 22.08 MPa. 100% variation, compressive strength: 7 days 14.72 MPa, 14 days 19.34 MPa, and 28 days 25.48 MPa. The split tensile strength of concrete decreases with an increasing percentage of beach sand: normal 28-day concrete 7,852 MPa, 25% variation 6,222 MPa, 50% variation 6,963 MPa, and 100% variation 8,000 MPa

Biological traits and functional diversity of free-living nematode assemblages along a water-depth gradient in the northwestern of Gulf of Mexico

This study analyzed the biological traits (BTs) and functional diversity (FD) of free-living nematodes in the northwestern of Gulf of Mexico. We collected sediment samples at 27 sites at a depth gradient from 44 to 3466 m. The nematodes were identified at species level and classified in five groups of BTs: feeding type, amphid shape, tail shape, body shape, and body length. We determined the FD based on the combination of BTs through a functional dendrogram, using the total length of the branch as a measure of functional diversity. Salinity, pH, and dissolved oxygen were measured in each site, as well as the sediment composition and percentage of organic carbon (OC). A total of 1673 nematodes were identified, belonging to 35 families, 96 genera, and 153 species. The number of species varied along water depth (1–60 species). The more abundant BTs were the non-selective deposit feeders (49 %), amphid spiral shape (55 %), clavate conical cylindrical tail (52 %), sizes 1000–1500 μm (51 %), and body shape slender (97 %). The most common combination of traits was non-selective deposit feeders, spiral amphid, clavate conical cylindrical tail, slender shape, and sizes < 1500 μm. The changes of BTs with increasing depth were more evident in the feeding types and amphid shape. The FD fluctuated between sites (0.42–0.99) and was significantly correlated with the number of species, suggesting that taxonomic and functional diversity have similar responses to environmental variables. The FD was significantly influenced only by the percentage of sands. Our data provide valuable information that can be used in subsequent studies and benthos monitoring.

Depth Wise Distribution of Soil Physico-Chemical Properties and Nutrients Across a Toposequence Located at KVK Farm, Sakhigopal, Odisha, India

This study aims to identify soil-related constraints for crop production and provide insights for soil management by analyzing soil profiles across different topographic positions (upland, medium land, and lowland) at KVK farm, Sakhigopal, Puri located in the East and Southeastern Coastal Plain Agro-Climatic Zone of Odisha. The profiles were evaluated for key physico-chemical properties and nutrient contents, revealing significant variations influenced by topography. The results showed that the soil's physical and chemical properties and available nutrient status showed distinct variations among the pedons. Among soil physical properties, the sand percentage, bulk density, and particle density increased with soil depth. Whereas, the clay percentage, total porosity, and water-holding capacity decreased with soil depth. Soil pH ranged from 6.32 to 7.50 and the electrical conductivity was recorded below 1 dSm-1. The organic carbon content ranged from 8.6 to 10.3 g kg-1. In general, soil pH, base saturation, and exchangeable cations increased with soil depth. On the other hand, soil organic carbon content and exchangeable acidity decreased with soil depth. Available nitrogen, phosphorus, potassium, and sulphur contents decreased with soil depth. However, in general, their concentrations increased along the slope (towards low land), which may be attributed to increased levels of organic carbon and clay contents in the lower topographic positions owing to high moisture content and higher cropping intensity. The findings of this study provide valuable insights regarding soil property characterisation across a transect for sustainable land use planning.

Landscape Dynamics and Environmental Fragility Zoning in Hinh River Basin: Insights for protecting natural ecosystems

The landscapes in the Hinh River Basin are crucial and highly sensitive to climate change for the coastal province of Phu Yen and the entire south-central coastal region of Vietnam, offering vital environmental services to its downstream areas. Hinh River Basin has a rich system of rivers and streams and abundant surface water resources. However, it remains one of the region's top localities at risk and a very vulnerable region. This study aims to evaluate the changes in landscape (LC) over 10 years (2010-2023) and predict LC over the next six years using machine-learning (ML) algorithms on Google Earth Engine. To achieve these study goals, we establish: (i) potential environmental fragility (PEF) levels based on: terrain slope; geological domains; river hierarchy; percentage of sand in soil; annual mean precipitations; and (ii) emergent environmental fragility (EEF) levels through the addition of LC parameter to model. The methodology includes integrating the Analytic Hierarchy Process (AHP) into a Geographic Information System (GIS). Results show that three LC types (water, annual industrial crop, forest) are related to extremely high EEF. The predictive model suggests that, by 2030, the forest and annual industrial crop LCs in the study area will increase by around 20%. The analysis results show that there has been an increase in the area of planted forests, which can confirm the futher effectiveness of agricultural, forestry, afforestation and forest protection programmes in the study area (Plan for the implementation of forestry development strategy for the period 2021-2030, with a vision to 2050, Phu Yen Province, No 126/KH-UBND 13/7/2021; and Decision on the approval of the project for planting 15 million trees in Phu Yen Province for the period 2021-2025, No 1646/QĐ-UBND 16/11/2021).

Predicting soil hydraulic conductivity using random forest, SVM, and LSSVM models

AbstractUnderstanding the hydraulic properties of soil is essential to solve many management problems in agriculture and the environment. Water quality affects soil hydraulic conductivity. Soil hydraulic properties play an important role in nature's water cycle and are used as basic information in designing irrigation and drainage systems, hydrological issues, and soil quality assessment. In the current study, soil sampling is performed from different areas and its hydraulic conductivity was measured using the drop load method and then predicted using support vector machine (SVM) and least‐squares support vector machine (LSSVM) models. The model inputs were: soil texture (percentage of sand, silt, and clay particles), salinity (electrical conductivity), pH, sodium adsorption ratio, soil porosity, and bulk density and the output was soil hydraulic conductivity. Correlation coefficient, root mean square error (RMSE), mean bias error (MBE), and Nash–Sutcliffe efficiency (NSE) were used to evaluate the models and compare them. Based on evaluation criteria the best performance was obtained for random forest (RF) (R = 0.89, RMSE = 0.53, mean absolute error (MAE) = 0.54, and NSE = 0.72). Following RF, the SVM with (R = 0.69, RMSE = 1.32, MAE = 0.69, and NSE = 0.48) performed better than LSSVM model.

Complex Permittivity of Adobe Verses Frequency and Water Content

The complex permittivity of adobe is measured using a coaxial probe system verses frequency (500 MHz to 7 GHz) and water content (0% to 6%). Measurements are performed using adobe samples collected from abode bricks. The geotechnical properties of the compressed earth bricks are characterized by (1) percentage of gravel, sands, and fines; (2) Atterberg limits; and (3) grain-size distribution. The variation in adobe complex permittivity verses frequency is measured at discrete levels of water content using small adobe samples exposed to controlled levels of constant humidity in an environmental chamber. The typical water content profile verses depth for an adobe brick is also determined.

Classification of expansive soils among problematic soils in the brazilian semiarid from artificial neural networks

The climatological and geomorphological conditions of the Brazilian semiarid region favor the formation of potentially expansive soils. The development of neural networks to identify and classify expansive soils in Pernambuco, and the need to export to soils across the semiarid region of Brazil is investigated in this study using a Multi-Layer Perceptron (backpropagation). The neural network was developed using 87 experimental data points, divided into three groups. The Training Group, consisting of 53 samples, using data inputs: sand percentage, clay percentage, plasticity index, activity index, and geological, pedological, and climatological classification. Selection Group, made up of 17 samples, was used to select the best network architecture, genetics algorithms formed of 7 inputs and 3 hidden nodes. The Test Group used 17 samples to evaluate the predictive accuracy of the expansion potential, obtaining an accuracy rate of 88,2%. This network was validated by applying it to 67 samples of problematic soils of the collapsible, expansive, and soft type from the Brazilian semiarid region, reaching an accuracy of 76,1%. Probabilistic Neural Networks were found to be efficient in evaluating the behavior of expansive soils, with the ability to deal with the absence of sample input data, demonstrating the ability to capture movement trends in the expansion of the soil surface, indicating the functions that introduce the effects of the composition potential on the expansion behavior, and determining the limit values of each of the input variables for the samples from the database used.

Soil Physical and Chemical Properties under Shea Tree (Vitellaria paradoxa) at Different Stages of Growth

Shea tree (Vitellaria paradoxa), is one of the dominant agro-forestry species in Otuke district of Northern Uganda. Due to its economic importance and, in line with the numerous threats the tree is faced with, there is an urgent need for measures to conserve this species, for example, through incorporating annual food crops in the Shea tree parkland. This, however, requires a better understanding of tree-soil-food crop interactions. A number of studies of this aspect either considered only the mature Shea tree gardens or did not provide a clear distinction between the physiological states of the Shea tree. This was the motivation for this study where we compare variation in soil properties under mature and young Shea tree gardens with sites not having trees in Okwang sub-county, Otuke district. Five soil samples (up to 15 cm deep for top soil and 15-30 cm for sub-soil) were obtained per treatment using a soil auger. Our results show that in the top soil, only percent sand varied among the treatments, while, in the sub-soil, only percentage nitrogen and average phosphorus varied among the treatments. We also found that percentage top soil organic matter and percentage of sub-soil sand had negative strong correlations with maize and soybean yields, while percentage sub-soil clay had a strong positive correlation with maize and soybean yield. We conclude that variations in soil physical and chemical properties under Mature and Young Shea gardens only occur for those properties that have a direct link to tree residues

Selection of sustainable construction material from recycled waste plastics by q-rung orthopair fuzzy SWARA-MABAC approach

Recycling of waste plastics and agro-industrial waste for the development of sustainable polymeric composites is recognized as a viable approach to overcome the detrimental environmental effects of plastics waste. Despite of immense potential of sustainable composites in the Circular Economy (CE), its implementation is still insignificant due to the lack of an effective material selection approach. The existence of several influencing aspects in the process of material selection considers it a multi-criteria decision making (MCDM) problem. In the present work, an Aggregation Operator (AO) based integrated Stepwise Weight Assessment Ratio Analysis (SWARA) and Multi-attributive Border Approximation Area Comparison (MABAC) has been proposed to deal with the issues of material selection for polymer based sustainable composites. Moreover, q-rung orthopair fuzzy numbers (q-ROPFNs) have been implemented to tackle the uncertainty in the information. The effectiveness of the proposed approach has been confirmed by different comparative and sensitivity investigations. The developed composites have shown excellent properties whereas the responses of the materials vary invariably with compositions. The proposed method has identified the amalgamation of 10 wt percentage of rice husk ash and 10 wt percentage of sand with 80 wt percentage of high-density polyethylene (HDPE) as an appropriate material for the development of sustainable floor tiles as the composites resulted to optimum mechanical performances and minimum abrasive wear. The proposed model gives reliable and robust results and is sensitive to the criteria weights and mathematical parameters. The outcome of the research has exposed that the suggested mathematical approach can be effectively applied for material selection of sustainable polymeric composites for different applications.

Fine‐scale phenotypic variation of a large herbivore in a pulsed environment

AbstractThe resource rule hypothesis predicts that geographic differences in body size among populations of organisms are due to the amount, availability, and quality of food resources. For instance, the body size of large herbivores is often correlated with soil characteristics because better soils produce better forage. In semiarid environments, rainfall variation is an important driver of forage availability, especially highly nutritious annual forbs. Thus, in such pulsed‐resource environments, it is unclear whether the body size of large herbivores is influenced by fixed resources correlated with soil characteristics, irregular resource pulses correlated with rainfall, or both. Furthermore, it is not clear whether phenotypic expression is a function of forage quality or quantity. During the early autumns of 2011–2018, we captured 4554 white‐tailed deer (Odocoileus virginianus) on seven rangeland sites in the semiarid climate of South Texas, USA. The sites range from coastal to 140 km inland and represent gradients in both soil texture and annual rainfall. We recorded age‐ and sex‐specific indices of skeletal size, antler size, and body mass. Site‐specific soil characteristics explained most of the variation in skeletal size; percent sand was inversely related to skeletal size. For environmentally sensitive phenotypes (antler size and body mass), both soil characteristics and rainfall were influencers; increases in rainfall reduced the negative effect of sand. Percent sand and rainfall were positively correlated with annual biomass of preferred forbs, yet all phenotypic traits declined with increases in forb quantity. Increases in percent shrub cover increased all phenotype sizes. Our data suggest that the phenotypic expression of large herbivores in semiarid environments is driven by forage quality via edaphic characteristics rather than forage quantity via rainfall. Specifically, less sand in the soil allows for the development of shrub communities, which in turn provide a consistent source of forage in a variable, pulsed‐rainfall environment. Although forbs are of higher quality, they are highly ephemeral. The availability of a consistent source of forage may enable white‐tailed deer to extend time invested in body growth, which results in greater phenotype size. Our findings align with the resource rule hypothesis that identifies resource availability as a fundamental element explaining geographical variation in phenotypic expression.

Compressibility of expansive soil mixed with sand and its correlation to index properties

Prior research has primarily focused on Atterberg limits, void ratios, and/or water content, often disregarding the impact of coarse material percentage in the soil, which significantly affects compressibility behavior. This paper examines the effects of sand content, initial degree of saturation, and initial dry unit weight on the compressibility behavior of expansive soils. Ninty-six oedometer tests were performed in order to accurately predict the compressibility behavior of expansive soils. The previous studies have attempted to correlate compressibility with different index properties separately, but no single study has taken into consideration all properties influencing compressibility behavior, especially for expansive soils. The findings show that compressibility is greatly influenced by the sand content, initial degree of saturation, and initial dry unit weight. Increasing the initial dry unit weight specifically lowers the compression index and permeability while raising the recompression index for the same percentage of added sand. Moreover, since swelling reduces with increasing initial saturation, raising the saturation degree also lowers the permeability, recompression index, and compression index. The results indicate that a sand content of more than 30 % is recommended for achieving desired properties in expansive clayey soil. This is a result of sand taking the dominant role in the soil mixture, which lowers soil suction and improves soil properties by reducing swelling, permeability, and compressibility. Symbolic regression equations were created to predict the compression and recompression indices, outperforming previous models in accurately predicting the compressibility behavior of expansive soils, considering the percentage of sand. The validation of these equations demonstrates their predictive capabilities.

Effect of Different Levels of NPK, Biochar and Azotobacter on Physico-chemical Properties of Soil on Cowpea (Vigna unguiculata)

In light of this, the following goals are present in the experiment "Effect of Different Levels of NPK and Biochar, Azotobacter on Physico-chemical Properties of Soil and Yield Attributes of Cowpea to calculate the impact of various NPK, Biochar, and Azotobacter dosages on the physical-chemical characteristics of soil. An excavated soil sample from the experimental site revealed that the land topography ranged from nearly level to sloped by 1% to 6%, with soil area falling into the Inceptisol order. The soil texture was sandy loam, with sand percentages of 62.65%, silt percentages of 21.09, and clay percentages of 16.26. The pH of soil was 6.89, and its electrical conductivity (EC) was non-saline (0.42 ds m-1). Organic carbon content was low to medium, available nitrogen was low to medium (280.78 kg ha-1), available phosphorus was 17.34 kg ha-1, and available potassium was 168.16 kg ha-1. Two factors with three levels of @NPK 0, 50, and 100% ha-1, three levels of @Biochar 0, 50, and 100% ha-1, and a randomized block design were used in the statistical analysis. During field testing, nine different treatments were used; the best outcomes were significant. The results indicate that the physical and chemical parameters of the soil, including the cumulative mean values for bulk density (1.39 and 1.41 mg m-3), particle density (2.46 and 2.47 mg m-3), and soil pH (6.89 and 6.91), attained their maximum in T1 (Absolute control) at depths of 0-15 cm and 15-30 cm, respectively. Additionally, the percentage pore space was found to be 48.22% and 47.39%, and the water holding capacity was found to be 44.14% and 45.34%), electrical conductivity (EC) was measured at 0.49 ds m-1 and 0.52 ds m-1, the percentage of organic carbon was determined to be 0.40%), and the available nitrogen was found to be (299.78 kg ha-1 and 295.76 kg ha-1, available phosphorus was (23.78 kg ha-1 and 21.98 kg ha-1), and the available potassium was (179.25 kg ha-1 and 176.56 kg ha-1).