Sandy Clay Research Articles

Suitability techniques for transforming marginal lands to support building infrastructures in parts of Rivers State, Nigeria

This study examined sustainability techniques for transforming marginal lands to support building infrastructures in parts of Rivers State, Nigeria. The study adopted the cross-sectional survey research design method employing the use of standard penetration approach utilizing Geographic Information System analysis. Marginal lands were delineated as margins of watrbodies using the polygon method in ArcGIS, and were created as a feature class for polygon data (shape file). The locations, river margins and roads formed point data, polygon data and line data respectively. Digitisation was achieved using Orthophoto Image in ArcGIS 10.0 software where seven geotechnical boreholes were located and drilled using permission rig to a depth of 10.5m in five local government areas of Rivers State. In-situ standard penetration testing and soil sampling for laboratory geotechnical properties was done using standard laboratory techniques. Findings of the analysis show that silty and sandy clay are the dominant soil within the foundation depth of 1-2.5m which are underlained by clays and sands of varying densities and grain sizes with their specific gravity value of ranges of 1.9 – 2.66 depicting that the areas are underlined by organic, diatomaceous and high porosity permeability soils deposits under water logged conditions. The cohesive strength of the soils vary from 65KN/m 2 - 115KN/m 2, angle of internal friction ranged from 0o – 10o and shear strength ranged from 110KN/m 2 – 147.46KN/m 2 and the allowable bearing capacities of 180.22KN/m 2 – 236.05KN/m 2. The stability techniques for the transformation of the land to support building infrastructures are pre-construction soil stabilization and marginal land reinforcement. The study thus recommends for building summation of consolidated techniques for sustainability of infrastructures.

Eggshells Improve Soil pH and P Availability in Sandy Loam and Sandy Clay Loamy Soil

The current effective method of mitigating soil acidity is the application of lime. However, the costs associated with acquiring lime make it challenging for small-scale farmers in South Africa. Therefore, the aim of this study was to evaluate the liming potential of ground eggshells relative to aglime and its effect on P availability in two acidic soils differing in textural classes, and its subsequent effect on the growth of Swiss chard (Beta vulgaris L.). Two soils used in the study were sandy clay loam, which had an initial pH of 4.52, and sandy loam with an initial pH of 5.23. Both lime sources were applied at a rate of 0, 1, 2.5, and 5 t/ha through incubation for 120 days. Our results indicated that applying eggshells and aglime significantly increased soil pH within 7 days (p < 0.05) compared to the 0-rate application across all application rates in both soil types. There were no differences (p > 0.05) in pH between the two applied lime sources. Plant-available P was not significantly different between the applied lime sources at all application rates and the 0-rate application; however, the two lime sources increased plant-available phosphorus above 25 ppm, which is the minimum health level of plant-available phosphorus. The results of plant yield showed no differences (p > 0.05) between the plant dry weights. However, Swiss chard growing at the 0-rate application in the sandy clay loam showed poor and stunted growth while Swiss chard growing at the 0-rate application in the sandy loam did not exhibit poor and stunted growth. According to the study’s results, eggshells have a similar liming effect as aglime and their dissolution rate is similar; therefore, eggshells can be used as a substitute of aglime to increase soil pH. Using eggshells as a substitute for aglime could offer substantial benefits to small-scale farmers by reducing input costs and providing a locally sourced, sustainable alternative. This approach can also enhance economic sustainability in rural communities by promoting the recycling of agricultural by-products and making essential soil amendments more affordable and accessible.

Rainfall Patterns and Groundwater Dynamics: Implications for Soil and Water Conservation in Kodihalli Sub-Watershed, Haveri District, Karnataka, India

The Kodihalli sub-watershed (4D4D2f) is lies between 14028’23.68”-14034’20.103” North latitudes and 75026’49.224”-75031’44.208” East longitudes and covers an area of about 4398.83 ha. with an average annual rainfall of 783.0 mm (2014-2021). The maximum rainfall of 439.0 mm is received from June to September, 226.0 mm from October to early December and the remaining 118.0 mm is received during the rest of the year. The number of rainy days (>2.5 mm) varied from 13-24 days per year. On an average, the number of rainy-day events likely to produce runoff (20 to 30 mm) are about 2 to 8 rainy days per year with moderate variation across the years. The Actual Evapotranspiration (AET) over the years 2014 - 2021 in the Kodihalli sub-watershed varied from 383.0 to 770.0 mm. During 2014 - 2021, the average annual AET (621.0 mm) was less than the average rainfall (783.0 mm). The average AET/P ratio between 2014-2021 was about 0.79 which is less than the sustainable limit of about 0.80. The soils of watershed viz., sandy clay loam (IR 10 mm/hr) and sandy clay (IR 14 mm/hr) resulted in more infiltration rate than clay (2 mm/hr) and clay loam soils (7 mm/hr). Soil infiltration during a rainstorm is closely related to a number of factors such as the intensity and kinetic energy of the rainfall, soil surface conditions and soil properties such as those related to aggregate stability. For effective soil and water conservation, maximum area of about 3769 ha (85.7%) requires graded bunding and 267 ha (6.06%) area requires contour bunding.

Tracing the origin of raw materials used for the production of ancient ceramics: a case study of multi-period archaeological sites in the Turopolje area (Continental Croatia)

The selection of raw materials for ancient pottery production was influenced by a variety of technological and cultural factors, underscoring the importance of characterising these materials to understand the technology of ancient societies. This research examines ancient ceramics from two multi-period archaeological sites: Staro Čiče-Gradišće (Neolithic, Copper Age, Copper/Early Bronze Age, Early Bronze Age, Late Bronze Age, Roman period, and Late Mediaeval period) and Kurilovec-Belinščica (Early Bronze Age and Middle/Late Bronze Age), alongside potential clayey raw materials collected near these settlements. Using a multi-analytical approach (optical microscopy, X-ray powder diffraction, mass and emission spectrometry, and laser granulometry), the research aims to determine the characteristics of the paste recipes (raw clay and tempers) and to examine the type and provenience of the raw materials used for ancient pottery production over different periods of the past (from the Neolithic to the Late Mediaeval period). The results showed that ancient potters preferred to use moderately plastic, sandy clay, while Bronze Age potters often used highly plastic clay. Potters utilised various non-plastic tempering materials, such as sands and gravels, grog, and mollusc shells, with their choice being influenced by the need to enhance technological properties as well as by regional and culturally determined pottery traditions. Most of the ceramics are of local origin, made from easily available raw materials that represent flood sediments of the nearby Sava River. However, non-local materials were detected in Neolithic samples, indicating the presence of exchange networks among those communities.

In Situ Seedling Establishment and Performance of Cyperus esculentus Seedlings

Cyperus esculentus seeds are often considered irrelevant for C. esculentus spread as their fragile seedlings would not establish or survive in agricultural soils. However, the ever-increasing spread and upsurge of genetically different clonal populations in NW-Europe raises questions about the establishment of C. esculentus seeds and the reproductive performance of seedlings. Indeed, little is known about the potential of C. esculentus seedlings to grow and propagate under outdoor conditions relative to plants grown from tubers. Seeds from different clonal populations were sown outdoors in various soil types and under different irrigation levels (rainfed, irrigated) to assess seed germination and seedling establishment. Additionally, two pot experiments were conducted with three different plant types (plants originating from mother tubers and from seeds harvested on open- or self-pollinated plants) obtained from eight clonal populations. Plant performance was investigated by measuring vegetative and generative parameters. Germination under outdoor conditions was significantly affected by clonal population and was highest in irrigated sand (5.3%). Germination in sand was 4.1 times higher in irrigated plots than in rainfed plots. In irrigated plots, germination was 3.8 and 4.7 times higher in sand than in sandy loam and clay, respectively. Depending on the year, three out of five to five out of six clonal populations produced more tubers when grown from mother tubers than from seeds. Maximal tuber reproduction factors of 1:965, 1:752, and 1:618 were achieved for plants from mother tubers and seeds from open- and self-pollinated flowers, respectively. Plants originating from open-pollinated seedlings have the potential to equal or exceed the vegetative reproductive capacity of plants originating from mother tubers. As a result of their ability to establish in situ and their substantial vegetative reproductive capacity, C. esculentus seedlings are highly relevant for agriculture and merit appropriate attention in any integrated weed management system targeting C. esculentus.

Revealing suitable habitats for Juniperus procera and Olea europaea tree species in the remnant dry Afromontane forests of Ethiopia: Insights from ensemble species distribution modeling approach.

Human activities and climate change pose a significant threat to the dry Afromontane forests in Ethiopia, which are essential for millions of people both economically and ecologically. In Ethiopia, trees are planted elsewhere even if they are not likely to be well suited to the area. This study aims to identify the suitable habitat for the most exploited Juniperus procera (J. procera) and Olea europaea (O. europaea) tree species in northern Ethiopia. As inputs, least correlated temperature, moisture, soil, and topographic variables were selected through a stepwise procedure. The study evaluated five individual and ensemble models using the area under the curve (AUC) and true skill statistic (TSS) values. The ensemble model outperformed with mean AUC of 0.95 and TSS of 0.78 for J. procera, while securing the second position for O. europaea with an AUC of 0.88 and TSS of 0.71. Climatic factors emerged as the most influential, followed by soil and topography. Suitable areas for both species were found when Isothermality (Bio3) values range from 52% to 62%, temperature seasonality (Bio4) of 16-29°C. Moreover, well drained soils with soil texture not heavier than sandy clay, and soil organic carbon ranging from 5 to 42 g kg-1 were found suitable. The optimal suitable altitude for J. procera and O. europaea was determined to be 2200-2600 and 2100-2500 m.a.s.l., respectively. The suitable areas for J. procera and O. europaea were estimated to be 3130 and 3946 km2, respectively. Furthermore, potential plantation areas were identified beyond Desa'a and Hugumbirda Grat-Kahsu protected forests, covering 2721 km2 (86.9%) for J. procera and 3576 km2 (90.6%) for O. europaea. These findings hold significance for the conservation and sustainable management of these valuable tree species in northern Ethiopia. We recommend implementing a similar approach for other locally restricted dry Afromontane tree species with wider potential distribution.

The Morphological Identification and Biodiversity of Earthworms in Babylon Province-Iraq

The present study is passing through the city of Babylon–Iraq during the period from Autumn 2023 to Spring 2024. Three stations representing various habitats were chosen for sampling. Our study involve the morphological identification of Earthworms and confirm the identification of nine species (Aporrectodea tuberculata, Aporrectodea rosea, Aporrectodea caliginosa, Amynthas grasilis, Dendrobaena platyura, Hormogaster redii, Lumbricus terrestris, Lumbricus rubellus and Polytoreutus finni). As well as measured some physiochemical parameters such as soil temperature ranged between (17.3-25.83C°), pH (5.66-7.06), Electrical conductivity (420-787.67µs/cm), Total Dissolved Solids (333.66-683.66 mg/L), Moisture content (5.22-9.24 %) and soil texture were Sandy clay in all stations. In order to get insight into the overall ecosystem health, various biodiversity indices were utilized such as Shannon-Wainer Index ranged between (1.26-2.75) and Simpson Index (0.15-0.59) to evaluate the basic Earthworms community structure, species distribution, and interactions. The study also demonstrates a significant relationship between species distribution and the environmental factors.

Safety Factor Analysis on the Stability of the Retaining Wall Structure in Cimahi City, Indonesia

Retaining wall is a construction built to hold the ground on the slopes. Retaining wall can be said to be safe if its safety factors have been taken into account.In this study will be calculated the security factor based on SNI 8640:2017 on the location to be built retaining wall located in the area of Cimahi City, West Java using the help of software with two-dimensional finite element method.Based on the soil type map, the majority of the Cimahi City area consist of Tuffaceous Clay and Sandy Clay soils, which are alluvial fan deposits of volcanic origin, with soil thickness ranging from 1 m to 5 m. Retaining wall structures using cyclopean concrete appear to be slimmer compared to those using stone masonry. The use of dolken wood piles as additional reinforcement in locations using cyclopean concrete can strengthen the structure on the sliding plane, thus preventing overturning. Based on the modeling, the use of this structure resulted in a safety factor value greater than 1.5, with a displacement of 20 cm.

Fabrication of carboxymethyl tamarind kernel gum-based hydrogel and its applicability in different types of soils for agronomy

An avant-garde agricultural hydrogel - Carboxymethyl tamarind kernel gum-poly sodium acrylate-polyacrylamide hydrogel was designed by free-radical polymerization of biopolymer: carboxy-methyl tamarind kernel gum and monomers: sodium acrylate, acrylamide, using N,N′ methylene bisacrylamide as crosslinker and potassium persulphate as initiator, to explore its application as a soil conditioner. It was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric techniques. Swelling was investigated at different pH and in saline solutions. The fabricated hydrogel absorbed 189 ml/g of distilled water. Minimal 0.1 % hydrogel-amended different soils unveiled an upswing in maximum water holding capacity: Sandy soil (43%), Clay soil (31 %), Silty soil (29 %) & Loamy soil (9 %).; decrease in porosity: Sandy (29 %) > Loamy (15.2 %) > Silty (6 %) > Clay (5.9 %), increase in available water content: Clay soil (17.52 %), Silty (13.45 %), Loamy soil (9.416 %), Sandy soil (10.375 %); increase in bulk density: Clay (1.7 %), Silty (5.3 %), Loamy (10 %) and Sandy (13%) as compared to control sample. These sequels were corroborated by water retention capacity in chickpea plants. The designed hydrogel, as a soil conditioner, was commendable in all types of soils but is worth applying in sandy and loamy soils. This hydrogel richly assists as a soil conditioner and boosts plant performance in a green eco-friendly way.

Propagation characteristics of show sea seismic wave in different underwater media

The propagation characteristics of sea seismic wave (SSSW) in different underwater media are different. This study mainly focuses on the propagation characteristics of SSSW in different underwater media to improve the detection ability of SSSW mines. The propagation of SSSW in different underwater media, including clay, sandy clay, sandstone, mudstone, hard stone, and dolomite, is simulated using the staggered grid finite difference method. The dispersive energy maps of different underwater media are extracted using the f-k dispersive energy extraction method. Compared with the results of Scholte wave dispersion characteristic equations, the simulation results are consistent with the theoretical results. At the same time, the attenuation law of the SSSW train is obtained. The results provide a theoretical basis for developing SSSW mine fuses.

The Usefulness of Soil Penetration Resistance Measurements for Improving the Efficiency of Cultivation Technologies

The research results of soil penetration resistance (SPR) tests carried out on sandy clay using four cone probes with different dimensions of the measuring tip are presented in this study. It was indicated that the values of SPR can be used to diagnose the cultivation layer and, on this basis, determine whether it is necessary to cultivate it and select tools for the required treatment. Tests were carried out on three levels of soil density, 1.37, 1.43 and 1.51 g∙cm−3, and two moisture contents, 7.64% and 10.4%. The results show that the probe with the smallest cone with apex angles of 30° and 60° on the least dense soil indicated higher SPR by over 50% more than other probes with the highest cone and the same opening angles. The change in cone opening angle from 30° to 60° led to an increase in probe indications in the range of 10–25%, depending on the diameter of the cone tip. The statistical analysis shows that values of probe indications were statistically significant and were influenced by soil density, probe cone tip dimensions, the surface of the base and the apex angle. The values of SPR are fundamental in diagnosing the quality of the soil’s top layer, determining the necessity of breaking it up, and selecting the optimal tools for this procedure. To improve the efficiency of agricultural crop cultivation technologies. This is particularly important when carrying out cultivation procedures in an environmentally friendly manner. The measurements will help support the introduction of sustainable farming practices, including direct seeding, no-till cultivation, or precision agriculture, reducing soil degradation and increasing environmental benefits.

Estimating equivalent elastic properties of frozen clay soils using an XFEM-based computational homogenization

This study addresses the challenge of estimating the elastic properties of heterogeneous frozen clay soils by introducing a comprehensive approach that combines analytical and numerical models. The frozen clay soil is treated as a mixture composed of frozen clay-water composites and nonclay mineral inclusions. An inversion algorithm is employed to deduce the elastic properties of the matrix (clay-water composites) of two artificially frozen sandy clay samples with known temperature-dependent elastic properties. Subsequently, a two-dimensional numerical simulation using the eXtended Finite Element Method (XFEM) is conducted to carry out numerical homogenization by considering the imperfect bond among frozen clay-water composites and nonclay minerals. The numerical homogenization model offers insights into the temperature-dependent behavior of the interface stiffness parameter. The numerical homogenization results are compared with conventional numerical homogenization approaches like the FEM, which rigidly defines the bonding between inclusions and the matrix. The comparison indicates that the neglect of imperfect bonds among clay-water composites and nonclay minerals will lead to unrealistic outcomes in cases with a high fraction of inclusions. This integrated approach advances the understanding and prediction of elastic properties of frozen clay soils by considering their heterogeneous nature.

Evaluation of specific retention, specific yield, and storage-dependent drainability efficiency in a coastal milieu via geo-electrical technology

ABSTRACT The aim of this research was the application of geo-electrical technology in the determination of specific retention, specific yield, and storage-dependent drainability efficiency within a major coastal milieu in Nigeria. This improves on past work where expensive and time-intensive pumping tests were employed to determine specific retention and specific yield. In addition to the determination of these key aquifer geo-kinetic properties, other important aquifer characteristics such as aquifer potentiality, protectivity, and vulnerability to contamination within this major coastal system were determined. Geo-electrical technology employed Wenner and Schlumberger arrays to undertake Vertical Electrical Soundings (VES) and Electrical Resistivity Tomography (ERT) surveys and results obtained were constrained by ground truth from lithological logs. Results from the electrical resistivity surveys indicated that the lithological strata comprised motley topsoil, coarse sand, fine sand, and sandy clay. Measures of specific yield and specific retention were generated as secondary geo-electrical indices. Specific yield intersected with specific retention at 73% storage-dependent drainability efficiency (SDE), indicating that this percentage must be exceeded for optimal groundwater extraction from the rock matrix's pore spaces during pumping. Aquifer transmissivity measures indicated high aquifer potentiality; longitudinal conductance measures indicated poor aquifer protectivity implying increased vulnerability of the aquifer to contamination.

Geoelectrical and seismoelectric mapping of subsurface pollution in a closed landfill near the Tongo Bassa and Ngongue river, Douala Cameroon

Located in Douala V (Cameroon), Makepé Missoké is a lowland area that is influenced by the Tongo Bassa and Ngongué rivers. The site has a closed dumpsite, that operated from the 1975’s to 2003 for the disposal and storage of domestic waste produced in Douala. Geoelectric profiling (ERT) coupled with seismo-electric imaging was used to characterize the shallow aquifer of the Douala subbasin and map subsurface pollution. Fourteen geoelectrical profiles were deployed between June and August 2018 and March 2019. Along these lines, 49 sets of seismo-electric point data were collected in December 2021. A total of 118 wells drilled (2018) were used to obtain water level and topographic data. The aquifer geometry, hydraulic characteristics, permeability, lithology and leachate plume extent were determined. This survey enables us to visualize waste infiltration and migration within Makepé. The drilled wells indicate that the main lithologies observed are clay, sandy clay, sand, clayey sand and gravel. The leachate plume observed after processing the electric profiles had a resistivity signature of ≤ 10 Ωm, and high electrical conductivity are observed in some wells. The leachate migrates within the subsurface along a northwest‒southwest trend, where ground water pollution is observed due to leachate infiltration. This infiltration resulted in poor water quality indices in some collected samples. Such pollution is common in unconfined aquifers (< 50 m) due to the absence of a confining layer at the landfill. An increase in resistivity values with depth toward the northeast direction indicates progressive vertical dilution during leachate mineralization. This study integrated geoelectric and seismo-electric tomography with basic water chemistry analysis to effectively characterize the groundwater within the phreatic Quaternary/Mio-Pliocene aquifers of the Douala basin.

Improving the thermal performance of vertical ground heat exchanger by modifying spiral tube geometry: A numerical study

Ground heat exchanger (GHE) is the most crucial element of a ground source heat pump (GSHP) system for building cooling and heating by the utilization of geothermal energy. Therefore, intending to enhance the performance of GHE, the present study conducts a computational investigation of the thermal performance of modified spiral tube vertical GHEs. Several modifications of uniform-pitched spiral GHE are made to increase its thermal performance. Some modifications are introduced as variable-pitched spiral tube GHE where spiral inlet pipes are densified in the lower part of GHEs by reducing pitch distance. Conversely, in some modifications, the position of the outlet straight pipe is changed. Water is considered as the working fluid and the inlet temperature of the water is maintained fixed at 300.15 K. After extensive analysis, it is evident that, when the outlet pipe is placed outside of the spiral coil, there is a 7.67 % enhancement in the thermal performance than a traditional uniform-pitched spiral tube GHE. However, modifications like variable-pitched spiral tube GHEs are not significant to improve the thermal performance due to the quick saturation of the ground soil temperature around the GHE pipes. To have a balance between heat transfer rate and pressure drop, thermal performance capability (TPC) and coefficient of performance improvement (COPimprvt) criterion were evaluated and it is found that the uniform-pitched spiral tube GHE along with the outlet pipe at the outside of the spiral provides maximum thermal performance with a maximum TPC value of 1.062 and provides the positive value of COPimprvt criterion. The positive values of COPimprvt indicate that the spiral tube GHEs are energy efficient based on heat transfer and pressure drop. Moreover, spiral GHE with high-density polyethylene (HDPE), concrete pile, and sandy clay outperform the other materials for pipe, backfill, and soil, respectively. Specifically, HDPE pipe, concrete backfill, and sandy clay as soil offer around 7 %, 5 %, and 7.8 % higher thermal performance compared to polyethylene, sand silica, and clay, respectively.

Geophysical and Geotechnical Investigation of Building’s Foundation around Crusher area, Lokoja, Kogi state, Nigeria

Integration of geophysical and geotechnical techniques had been utilised to investigate the foundation of a site characterised with building cracks. It was conducted at Muhammadu Buhari Estate, Crusher area in Lokoja, Nigeria, The study aims to delineate geological features responsible for the failure of the building through 2-D resistivity imaging and electromagnetic surveys in conjunction with geotechnical analysis. Seven 2-D electrical resistivity imaging traverse lines, seven electromagnetic profiles were run and seven soil samples were collected and analysed. Each of the sample point were located on each of the 2-D imaging traverse. Traverses 1-7 host samples 1-7 respectively. The findings revealed high conductivity in unstable areas (resistivity ranging from 11-42 Ohm-m, 1-38 Ohm-m, 4-12 Ohm-m, 1-15 Ohm-m, and 11-30 Ohm-m for traverse 1-5, respectively) and low conductivity in stable ones (resistivity ranging from 19-91 Ohm-m and 109-2056 Ohm-m for traverse 6 and 7, respectively) and they occur at near surface to a relatively shallow depths (ranging from 0-6m depth) in all the profile. Geotechnical analysis showed high clay content in the soil, affecting its engineering properties in most of the studied locations. Soil grain oversize data analysis indicated a range between 70.1% and 75.1% for unstable portions (samples 1-5), with an average of 72.22% fines while percentage coarse ranges between 24.9 and 29.9 with an average of 27.78%. Their optimum moisture content ranged from 10.4% to 11.50%, with a mean value of 11.18%. Also, their plastic index averaged at 10.044%, while linear shrinkage varies between 1.79% and 3.60%, with an average of 2.808%. All these are the responsible factors for the soil instability in this axis of the investigated site. But for the stable portions (samples 6 and 7), Soil grain oversize data analysis is between 18.1% and 18.2% with an average of 18.65% fines while percentage coarse range between 81.9 and 80.8 with an average of 81.35%. The optimum moisture content ranged from 10.4% to 11.50%, with a mean value of 11.18%, the optimum moisture content ranged from 11.3% to 12.0%, with a mean of 11.65%, the plastic index equals zero (0), linear shrinkage varies between 5.57% and 5.71%, with an average of 5.64% and all these parameters are responsible for the stability of these two portions. The California Bearing ratio (CBR) results graded the soil samples into different types with the unstable portion characterised with clay, silty clay and sandy clay while the stable portion are classified into well graded sands. The well graded sands are very suitable for the engineering construction and hence the buildings on this portion showed no cracks and failure because of lack of differential settlements unlike that of the unstable portion characterised with cracks due differential settlements that led to structural failure at those sides of the study site. The geophysical results corroborate well with geotechnical results and these highlight the value of combining geophysical and geotechnical techniques to evaluate the integrity of the subsurface, providing information that is essential for designing infrastructure foundations and determining stability.

Response of Soil Microbiota, Enzymes, and Plants to the Fungicide Azoxystrobin.

The present study was aimed at assessing the impact of azoxystrobin-a fungicide commonly used in plant protection against pathogens (Amistar 250 SC)-on the soil microbiota and enzymes, as well as plant growth and development. The laboratory experiment was conducted in three analytical terms (30, 60, and 90 days) on sandy clay (pH-7.0). Azoxystrobin was applied to soil in doses of 0.00 (C), 0.110 (F) and 32.92 (P) mg kg-1 d.m. of soil. Its 0.110 mg kg-1 dose stimulated the proliferation of organotrophic bacteria and actinobacteria but inhibited that of fungi. It also contributed to an increase in the colony development index (CD) and a decrease in the ecophysiological diversity index (EP) of all analyzed groups of microorganisms. Azoxystrobin applied at 32.92 mg kg-1 reduced the number and EP of microorganisms and increased their CD. PP952051.1 Bacillus mycoides strain (P), PP952052.1 Prestia megaterium strain (P) bacteria, as well as PP952052.1 Kreatinophyton terreum isolate (P) fungi were identified in the soil contaminated with azoxystrobin, all of which may exhibit resistance to its effects. The azoxystrobin dose of 0.110 mg kg-1 stimulated the activity of all enzymes, whereas its 32.92 mg kg-1 dose inhibited activities of dehydrogenases, alkaline phosphatase, acid phosphatase, and urease and stimulated the activity of catalase. The analyzed fungicide added to the soil at both 0.110 and 32.92 mg kg-1 doses inhibited seed germination and elongation of shoots of Lepidium sativum L., Sinapsis alba L., and Sorgum saccharatum L.

Enhancing Mangrove Resilience: Assessing Rhizophora sp. Survival in Davao Occidental’s Conservation and Rehabilitation Zones, Philippines

Three distinct sampling locations within Davao Occidental, namely Brgy. Sto. Rosario in Sta. Maria municipality, Sitio Tawang in Brgy. Buhangin, and Sitio Agdao in Brgy. Tubalan in Malita municipality were investigated to evaluate the survival of planted mangroves (Rhizophora sp.). The study revealed a notable discrepancy in survival rates among the sites, with Sitio Agdao exhibiting the highest survival with 97.58%, followed by Sto. Rosario (91.84%), and Sitio Tawang registering 70.46% survival rate. No significant variance was observed between survival rates in Sta. Maria and Malita. Findings indicated diverse causes of mangrove mortality, including strong waves during northeasterly winds impacting Sto. Rosario, flashfloods affecting Sitio Tawang, and the presence of epiphytes (specifically barnacles) in Sitio Agdao. Among the sites, Sitio Tawang exhibited significantly lowest survival rates compared to Sto. Rosario and Sitio Agdao. Substrate analysis revealed clay loam in Sto. Rosario, sandy loam in Sitio Agdao, and sandy clay in Sitio Tawang. The study recommends extending mangrove survival rate monitoring to other conservation and rehabilitation areas, continuing mangrove rehabilitation efforts, and manually removing epiphytes to enhance survival rates.

Impact of Stress Induced by Unfavorable Soil Conditions on the Germination, Seedling Developmentand Stress Tolerance Indices of Browntop Millet (Brachiaria ramosa L.)

Background: Browntop millet, a traditionally cultivated yet underutilized millet, is abundant in iron, zincand fiber. It can thrive in diverse soils and climates, adapting well to a broad spectrum of ecological conditions. Assessing the performance of Brown top millet in various challenging soils prevalent across Tamil Nadu could provide valuable insights into its adaptability and potential for cultivation in different soil conditions. The evaluation focuses on its germination, seedling growthand stress tolerance indices in these diverse soil environments. Methods: The pot experiment was carried out in the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore during Kharif 2023 season. Six soil types were collected from different zones in Tamil Nadu and tested in a completely randomized design with four replications. Germination, seedling growth and stress tolerance indices were calculated by using standard formula. Result: Results of the investigation revealed that the treatment with sandy clay loam soils of Eastern Block 37B TNAU, Coimbatore (T1) recorded higher germination and seedling growth indices. The lowest values were recorded with the sodic soils of ADAC and RI, Trichy (T6). The higher stress tolerance indices were recorded with the heavy clay soils of Cotton Research Station (CRS), Veppanthattai, Perambalur district (T2)and acidic soils of Anaikatti, Coimbatore district (T3).

Identification of Aquifer Layer Using Geoelectric Method in Oil Palm Plantation Area of PT Unggul Widya Teknologi Lestari Pasangkayu Regency

Introduction: Aquifer layers have been identified in the oil palm plantation area of PT Unggul Widya Teknologi Lestari Pasangkayu Regency. This study aims to determine the lithology of subsurface rocks and the depth of the aquifer layer as a source of clean water in the study area. Method: This study uses the geoelectric method of type resistance with Wenner configuration, with the number of electrodes 24 rods and a spacing of 10 meters. 2D cross-sectional model using Res2Dinv software program. Results and Discussion: Based on the value of the type resistance of the subsurface constituent rock lithology at the research site is interpreted to consist of three layers, namely clay with a specific resistance value < 29.15 Ωm, sand and sandy clay with a specific resistance value of 29.15 Ωm to 72.89 Ωm, and conglomerate with a specific resistance value > 72.89 Ωm. The aquifer layer is interpreted with a specific resistance value of 29.15 Ωm to 72.89 Ωm. The aquifer layer is detected to spread from the northeast to the southwest of the research site with a depth of ±25-39 m. Conclusion: In the oil palm plantation of PT Unggul Widya Teknologi Lestari, the subsurface layer consists of clay (1.98 Ωm - 29.15 Ωm), sand and passive clay (29.15 Ωm - 72.89 Ωm), and conglomerate (72.89 Ωm - 1120.5 Ωm). Thin aquifers, with a thickness of 5-10 m and depth of 25-39 m, are detected in the sand and sandy clay layers.