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Maize is widely growth in arid and semi-arid region where, drought is common and a limiting factor for crop production. Potassium plays a key role in enhancing plant growth under drought condition. The objective of this study is to determine the effect of K fertilization with and without NP on maize growth grown in sandy loam soil under adequate and deficit irrigation conditions. The following treatments were investigated in pot experiment: (1) control with no fertilizer application (C); (2) 128 kg N + 328 kg P2O5 ha-1 (NPK0); (3) 128 kg N + 328 kg P2O5 ha-1 + 152.5 kg K2O ha1 (NPK1); (4) 128 kg N + 328 kg P2O5 ha-1 + 305 kg K2O ha-1 (NPK2); and 128 kg N + 328 kg P2O5 ha-1 + 457.5 kg K2O ha-1 (NPK3). Treatments were investigated under adequate and deficit soil moisture content. Each pot filled with 3.5 kg air-dry soil and seeded with maize and pots were watered according to the treatments. The results indicated that plant growth and nutrient uptake were significantly reduced under water stress condition. The application of NP increased plant growth and nutrient uptake and further were increased with K application. K application also enhanced plant tolerance to deficit soil moisture condition. In addition, K enhanced nutrient uptake and leaf chlorophyll content. Based on the results, it can be concluded that application of NP for maize was not adequate to achieve the highest plant growth, unless it is combined with K application. In addition, K application enhances plant tolerance to water stress. [ABSTRACT FROM AUTHOR]

Copyright of Fly Ash Comprehensive Utilization is the property of Hebei Fly Ash Comprehensive Utilization Magazine Co., Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was conducted to determine the effect of different jajar legowo planting systems in intercropping sweet corn with peanuts, as well as the addition of several doses of organic fertilizer on soil nitrogen status and plant leaf tissue on sandy soil. The research was conducted from January to May 2023 on the south coast of Jember Regency. The study used a split-plot design; the main plot consisted of the treatment of 2:2 (A1) and 4:2 (A2) jajar legowo intercropping systems. The subplots were different doses of cow dung organic fertilizer: 10 t ha-1 (B1), 20 t ha-1 (B2), and 30 t ha-1 (B3), each repeated three times. Observational data were analyzed by ANOVA and DMRT 5%. The results of the study showed that the combination of the planting system and organic fertilizer doses had not been able to provide optimal microclimate and soil properties for the growth and development of sweet corn plants. The A2 planting system provides a better microclimate and plant morphology for plant N availability and absorption. The addition of organic fertilizer up to the highest dose (B3) has not been able to maintain optimal soil water and N availability for sweet corn in sandy soil. [ABSTRACT FROM AUTHOR]

This study investigated the efficacy of biochar as a soil amendment for enhancing soil physicochemical properties and solute transport dynamics, with implications for agricultural sustainability and environmental stewardship. Batch laboratory experiments and column studies were conducted to assess the effects of biochar application on soil parameters and solute transport under saturated conditions. The saturation soil extraction approach was employed in batch leaching tests, while column experiments replicated subsurface conditions. Transport modeling using CXTFIT 2.1 elucidated solute dispersion dynamics in biochar-amended soils. Batch experiments revealed significant alterations in soil pH, electrical conductivity, and nutrient release following biochar addition. Biochar exhibited adsorption capacity for fluoride ions and released dissolved organic carbon, highlighting its potential for soil carbon sequestration and microbial activity. Column studies demonstrated enhanced solute dispersion and increased microbial activity in biochar-amended soils, as evidenced by changes in breakthrough curves and degradation rates of nitrate. Indeed, nitrate first-order degradation coefficients were 9.08E-06 for the column with only sandy soil, 3.09E-05 and 1.47E-04 for the columns with minimum and maximum doses of biochar respectively. Biochar application significantly influenced soil physicochemical properties and solute transport dynamics, with potential implications for nutrient management and contaminant attenuation in agricultural systems. Despite limitations in laboratory-scale experiments, this research provides valuable insights into biochar-soil interactions. It underscores the need for further investigation under field conditions to validate findings and optimize biochar management practices for sustainable soil and environmental management. Highlights: The release of solutes following biochar application highlights the complex chemical biochar-soil interactions. Biochar application increased nitrate degradation coefficient in both minimum and maximum treatment. Biochar alters soil pore structure, leading to more extensive solute spreading. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Sciences & Agricultural Engineering is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Saturated hydraulic conductivity (Ks) is a crucial parameter that influences water flow in saturated soils, with applications in various fields such as surface water runoff, soil erosion, drainage, and solute transport. However, accurate determination of Ks is challenging due to temporal and spatial uncertainties. This study addresses the knowledge gap regarding the long‐term behavior of Ks in sandy soils with less than 10% fine particles. The research investigates the changes in Ks over a long period of constant head tests and examines the factors influencing its variation. Two sandy samples were tested using a hydraulic conductivity cell, and the hydraulic head and discharge were recorded for over 50 days. The results show a general decline in Ks throughout the test, except for brief periods of increase. At the end of both tests, there are noticeable reductions in the saturated hydraulic conductivities of the samples, with one sample being 96% and the other sample 91% less than the maximum recorded saturated hydraulic conductivity during the tests. Furthermore, the relationship between flow rate and hydraulic head gradient does not follow the expected linear correlation from Darcy's law, highlighting the complex nature of sandy soil saturated hydraulic conductivity. The investigation of soil properties in three different sections of the samples before and after the tests revealed a decrease in the percentage of fine particles and a shift in specific gravity from the bottom to the top of the sample, suggesting particle migration along the flow direction. Factors such as clogging by fine particles and pore pressure variation contribute to the changes in Ks. The findings of this research show the importance of considering changes of saturated hydraulic conductivity during constant‐head laboratory tests. Therefore, this study provides evidence for the requirement to further assess the laboratory methods for measurement of the saturated hydraulic conductivity in sandy soil mixtures. Key Points: The estimation of saturated hydraulic conductivity through constant head tests demonstrates sensitivity to the duration of the testsObservations indicate an alteration in particle size distribution before and after testing within different sections of the samplesFlow rate and hydraulic gradient vary over the test duration, emphasizing the complex hydraulic system within the samples [ABSTRACT FROM AUTHOR]

This study evaluates the performance of infiltration wells using full-scale field experiments and 3D numerical modeling with GeoStudio SEEP/W, focusing on sandy soils. Infiltration wells are essential for improving groundwater recharge, lowering urban runoff, and controlling flood risks. However, differences in soil qualities and external environmental circumstances are the leading causes of the frequent disparities between modeled predictions and field observations. The process consists of two primary steps: numerical modeling to duplicate these conditions and compare results and field testing to measure the amount of water absorbed by the soil during an hour. Detailed records of the attributes of the soil, including water content and grain-size distribution, as well as hydraulic conductivity, were made. The field results indicate a logarithmic increase in water infiltration, reflecting rapid initial infiltration that gradually plateaued, demonstrating the changes in soil saturation. However, the numerical model predicted a more consistent infiltration rate across similar intervals, highlighting a significant field-model discrepancy. Comparative analysis revealed that soil heterogeneity and initial moisture content significantly influence the infiltration rates, which were not accounted for entirely in the numerical model. External factors such as atmospheric conditions and unanticipated groundwater movement complicate accurate modeling. Enhancement of model parameters, incorporating comprehensive soil data, and integration of laboratory experiments are suggested to bridge the gaps between the numerical and field measurements. Furthermore, this research contributes to the sustainable management of groundwater resources by optimizing the design and implementation of infiltration wells, providing valuable insights for both practical implications and academic endeavors. [ABSTRACT FROM AUTHOR]

Efforts that can be made to increase the productivity of marginal soils are the addition of organic matter, biofertilizer pellets VP3 and Trichoderma viride. This study aims to determine the effect of the use of planting media residues of VP3 biofertilizer pellets and Trichoderma viride FRP3 in sandy soil left over from soybean cultivation on the yield and vitamin C content of green mustard plants (Brassica chinensis var. parachinensis). This study used the Randomized Group Design (RAK) method consisting of 6 treatments 4 replications. The parameters observed included plant height, number of leaves, leaf area, total fresh weight of plants, consumption weight and vitamin C. The results showed that the use of planting media residues of VP3 biofertilizer pellets, organic matter and Trichoderma viride FRP3 on sandy soil left over from soybean cultivation had a significant effect on the yield of green mustard plants compared to the control. The use of planting media of VP3 biofertilizer pellet residues, organic matter and Trichoderma viride FRP3 on sandy soil left over from soybean cultivation also significantly affected the vitamin C content of mustard greens. However, when compared to the potential standard of mustard greens, the vitamin C content is still relatively low. [ABSTRACT FROM AUTHOR]

Geohelminths (soil-transmitted helminths) tend to thrive in moist soil conditions, and the poor hygiene systems of underdeveloped countries have enhanced their transmission at an alarming rate. A cross-sectional study was conducted to determine the effects of soil type, pH, and temperature on geohelminths found in soil samples from Mkpat Enin LGA, Akwa Ibom State. The soil samples were examined using the centrifugal floatation method for geohelminth eggs and larvae. Among the 200 soil samples examined, an overall prevalence of 67.0% was recorded. Geohelminths recovered were Ascaris lumbricoides, which contaminated 38 (28.36%), Trichuris trichiura 27(20.15 %), hookworms 26(19.40 %), Strongyloides stercoralis 24(17.91 %), and Toxocara canis 19(14.18 %) soil samples. Soil samples obtained from farmlands and toilets had a higher contamination rate (82 %) than those from schools and roadsides (68.0% and 36.0%, respectively). Loamy soil recorded 77(66.38%) contaminated soil samples at a mean temperature of 28.7oC ± 0.1, and pH of 6.9 ± 0.03, compared to sandy soil with 32(69.57 %) at a mean temperature of (27.5oC ± 0.3) and pH of 5.7 ± 0.04, then clayey soil with 25(65.79 %) at a mean temperature of 27.0oC ± 0.1 and pH of 5.3 ± 0.04. There was no significant correlation between the prevalence of each geohelminth and soil type, temperature, or pH. The type of soil, soil temperature within the measured range, and soil alkalinity as measured do not appear to be major factors influencing the overall prevalence of geohelminths. The analysis also showed that these factors do not have a strong influence on the prevalence of individual geohelminth species. The eggs of these geohelminths were more abundant than their larvae. Periodic deworming programmes, health education, and improved sanitation will ultimately reduce the transmission of geohelminths. [ABSTRACT FROM AUTHOR]

A set of creative formulation is introduced to estimating the small-strain shear modulus (Gmax) of various sandy soils through the measurement of well-controlled laboratory tests combined with the analysis of experimental data published in the literature. The influences of normalized effective confining pressure ( σ c0 ′ /Pa), void ratio (e), and fines contents (FC) on the values of Gmax are revealed through a series of bender element measurements. Through introducing the equivalent skeleton void ratio ( e sk ∗ ) to describe the intergranular contact state of sandy soils with FC less than a threshold value (FCth), a remarkable finding is that the stress exponent n, characterizing the increase rate of Gmax with increasing σ c0 ′ , is a soil-specific constant and a linear function of the synthesizing material parameter ( C u s C u f ) in log-scale. Another remarkable finding is that a virtually unique form of the correlation between Gmax/( σ c0 ′ /Pa)n and e sk ∗ exists. An unified form of the binary packing material-based Gmax prediction formulation for different types of sandy soils is established. The three coefficients of the proposed Gmax expression in form of explicit equations can be simply determined using some basic index properties of clean sand and pure fines. In this regard, the proposed Gmax prediction formulation provides a significant advantage in the determination of Gmax and associated shear wave velocity Vs of sandy soils in practice. [ABSTRACT FROM AUTHOR]

Maize is widely growth in arid and semi-arid region where, drought is common and a limiting factor for crop production. Potassium plays a key role in enhancing plant growth under drought condition. The objective of this study is to determine the effect of K fertilization with and without NP on maize growth grown in sandy loam soil under adequate and deficit irrigation conditions. The following treatments were investigated in pot experiment: (1) control with no fertilizer application (C); (2) 128 kg N + 328 kg P2O5 ha-1 (NPK0); (3) 128 kg N + 328 kg P2O5 ha-1 + 152.5 kg K2O ha1 (NPK1); (4) 128 kg N + 328 kg P2O5 ha-1 + 305 kg K2O ha-1 (NPK2); and 128 kg N + 328 kg P2O5 ha-1 + 457.5 kg K2O ha-1 (NPK3). Treatments were investigated under adequate and deficit soil moisture content. Each pot filled with 3.5 kg air-dry soil and seeded with maize and pots were watered according to the treatments. The results indicated that plant growth and nutrient uptake were significantly reduced under water stress condition. The application of NP increased plant growth and nutrient uptake and further were increased with K application. K application also enhanced plant tolerance to deficit soil moisture condition. In addition, K enhanced nutrient uptake and leaf chlorophyll content. Based on the results, it can be concluded that application of NP for maize was not adequate to achieve the highest plant growth, unless it is combined with K application. In addition, K application enhances plant tolerance to water stress.

This study was conducted to determine the effect of different jajar legowo planting systems in intercropping sweet corn with peanuts, as well as the addition of several doses of organic fertilizer on soil nitrogen status and plant leaf tissue on sandy soil. The research was conducted from January to May 2023, on the south coast of Jember Regency. The study used a split-plot design; the main plot consisted of the treatment of 2:2 (A1) and 4:2 (A2) jajar legowo intercropping systems. The subplots were different doses of cow dung organic fertilizer: 10 t ha-1 (B1), 20 t ha-1 (B2), and 30 t ha-1 (B3), each repeated three times. Observational data were analyzed by ANOVA and DMRT 5%. The results of the study showed that the combination of the planting system and organic fertilizer doses applied had not been able to provide optimal microclimate and soil properties for the growth and development of sweet corn plants. The A2 planting system provides a better microclimate and plant morphology for plant N availability and absorption. The addition of organic fertilizer up to the highest dose (B3) has not been able to maintain optimal soil water and N availability for sweet corn in sandy soil.

Piled raft foundations are a popular solution for supporting heavy structures on weak soils, but their design and analysis can be complex due to interaction among the raft, piles and subsoil underneath. The present study utilises finite element method to analyse the parametric dependence of ratio of average settlement (λavg), ratio of differential settlement (λdiff), ratio of shear force (SFR), ratio of bending moment (BMR) and ratio of load-sharing (χpr), for square raft with underneath connecting circular cross section piles for uniformly distributed surcharge all over the top surface of raft. The parameters varied are spacing to diameter ratio (S/D) of 2-20, diameter of piles (D) of 0.4 m-1.6 m, length to diameter ratio (L/D) of 8, 12 and 16, pile group to width of raft ratio (Wg/Wr) of 0.15-0.9 and raft-soil stiffness (Krs) of 0.069, 0.558 and 1.88 corresponding to raft thickness (tr) of 0.5 m, 1.0 m and 1.5 m respectively. The results of the present study depicts that the minimum values of λavg and λavg are observed at S/D ratio of 5 (approx.), lower Krs and larger Wg/Wr. To enhance χpr, smaller pile spacing (S) and larger pile length (L) are needed. Minimum SFR and BMR are achieved at lower and larger L/D ratios, respectively. The findings can be used to guide the design and analysis of pile raft foundations for a variety of applications, including high-rise buildings, bridges, and industrial structures. [ABSTRACT FROM AUTHOR]

In this research, the effect of soil stabilization with cement at the same time as its reinforcement with fibers has been studied on the shear strength of sandy soil exposed to freeze-thaw cycles. In order to achieve this goal, laboratory studies were carried out with the help of unconfined compressive strength tests (UCS tests) on different compounds obtained from mixing cement, fibers, and sandy soil. More than 336 cylindrical laboratory models with dimensions including 3.6cm in diameter and 8cm in length have been made. Various modes have been observed during the failure of the samples, including shear, tensile, plastic yielding, and composite failure modes. The fibers used in the present research are waste products of tire factories known as DTY. Percentages of 2, 4, and 6 for cement and 0, 0.5, and 1 for fibers with lengths of 0.5, 1, and 1.5 cm were used relative to the weight of dry sandy soil in making the samples. Uniaxial cylindrical samples were tested for unconfined compressive strength after 7 and 28 days of curing time and under 0, 1, 2, and 3 freeze-thaw cycles. The results show that the act of stabilizing the soil with cement, along with reinforcing it to a certain amount of fibers, improves the uniaxial compressive strength before and after freezing and thawing cycles. This amount depends on the percentage of cement and the curing period. Also, adding cement in a certain curing time increases the unconfined compressive strength before and after applying the cycle, increases stiffness, reduces the ductility and toughness of the sample, and brittle failure when breaking occurs in the soil. Also, the addition of fibers, to some extent, improves the weaknesses caused by soil stabilization, such as reducing the failure axial strain, decreasing the residual strength, and the toughness of the materials in the conditions before and after freezing and thawing.

In the Kediri Regency area, it is planned to build a 3-story shophouse as one of the supporting facilities and the community’s economic needs. This area has sandy soil conditions and a high-water table. The purpose of this study was to calculate the carrying capacity of the soil in constructing a 3-story shophouse using the Terzaghi, Mayerhof, and Hansen methods. The condition of the soil with a relatively high groundwater table made the implementation of the footplate foundation less effective, so a modification of the foundation was made, which added three mini-piles measuring 0.4x0.4x1.5m, with a design load supported by the foundation of 100 t/m². Calculations with the Mayerhof and Hansen methods have nearly identical results but have not fulfilled the planned load. At a foundation depth of up to 3 m with an SF value of 3, for the Terzaghi method: 107.75 t/m2, the Mayerhof method: 92.51 t/m2, and the Hansen method: 94.68 t/m2. The results can be used as an alternative in constructing a 3-story shophouse with sandy soil conditions and high groundwater levels. This research can also be a reference for other regions facing similar problems.

Abstract A methodology combining physical experiments with simulation was employed to acquire contact parameters of sandy soil precisely for planting tiger nuts in the desert area of Xinjiang. The stacking angle under different parameter combinations was applied as a response value. Through the Plackett–Burman test, several factors that have a significant influence were determined. The steepest ascent test was conducted to establish the finest scope of values for these parameters. The stacking angle was considered the response variable, and non-linear tools were used to optimize these parameters for simulation. The findings showed that applying response surface methodology (RSM) resulted in a relative error of 1.24%. In the case of BP-GA, the relative error compared to the physical test value was 0.34%, while for BP, it was 2.18%. After optimization using Wavelet Neural Network (WNN), the relative error was reduced to only 0.15%. Results suggest that WNN outperforms the RSM model, and the sandy soil model and parameters generated using WNN can be effectively utilized for discrete element simulation research.

Coix lacryma-jobi L., an annual or perennial plant belonging to the Poaceae family, has long been cultivated as a food and medicine plant in China. In recent years, coix cultivation for high yields and good quality has become a research hotspot in Southwest China. Soil optimization is essential for improving crop growth. To ensure the robust establishment of coix plants, eight soil substrates, prepared from three typical soils, i.e., red clay soil, peat soil, and sandy soil, were used to cultivate two local coix varieties (Pu coix from Fujian Province, China; Qi coix from Hebei Province, China), and the plant growth and root coixol content of the two coix varieties were investigated. It was found that coix plants could maintain growth when cultivated with peat soil or sandy soil, but red clay soil was unfavorable for coix growth. The mixtures of sandy soils and peat soils resulted in synergistic benefits for coix growth and root coixol levels over the effects of sandy soil or peat soil alone. In conclusion, the mixtures of sandy soils and peat soils with appropriate proportions (sandy soils/peat soils = 2:1) were suggested as an ideal soil substrate for coix cultivation. The results provide valuable guidance for the establishment of coix plants, which could contribute to high yields and good quality in coix cultivation. [ABSTRACT FROM AUTHOR]

Managing waste tires presents a significant challenge globally, particularly in regions experiencing high temperatures and shortage of landfill sites. This issue is affecting countries like Kuwait, where the abundance of waste tires is a major source of environmental and safety risks, particularly during the intensely hot summer months. This extreme heat has sparked numerous fires, leading to substantial air pollution due to thick black smoke. Given the limited disposal options, recycling waste tires and finding practical applications for ground tire rubber (GTR) is essential. To address the challenge, a comprehensive laboratory testing program was conducted, using locally produced rubber aggregates as an additive to Kuwait's local surface sands. Two new variables were examined namely the size and gradation of the GTR, and the density of the compacted mixes. For this purpose, two different sizes of rubber aggregates, fine and coarse produced locally, were utilized, and the impact of relative compaction on the strength and compressibility of the mixtures was investigated by testing samples compacted to the maximum density and to 95% of the maximum density. The results suggest that combining local surface sands with rubber tire additives results in a lighter, more permeable, and compressible material, contributing significantly to sustainable waste management. With 20% rubber additive the maximum dry density decreased by nearly 20%, and the permeability increased by 1.74–3.11 times and the compression index increased by 6.15 and 3.8 times with fine and coarse rubber respectively. The angle of friction remained unchanged at 36° with the addition of coarse rubber and decreased by 3°–4° with fine rubber. The change in behavior although not an increase in the strength and stiffness, offers a range of suitable practical applications in civil engineering and environmental management, including use as a drainage layer, embankment construction on soft ground, earth fill around retaining walls, an additive in asphalt mixes, and in manufacturing compressible tiles for sports facilities. [ABSTRACT FROM AUTHOR]

Soil enzymes play a critical role in the biogeochemical cycles of essential nutrients and protect soil against the accumulation of harmful organic compounds. However, there is limited information on the effect of pesticides on enzyme activities in both old and newly reclaimed Egyptian soils. Laboratory studies were conducted to determine the effects of two nematicides (carbofuran and oxamyl) and two herbicides (ametryn and bentazone) on dehydrogenase and phosphatase activities in alluvial soil (clay soil) and calcareous soil (sandy soil) at concentrations of 25 and 100 µg/g soil over eight weeks. The results showed that dehydrogenase and phosphatase activities were generally enhanced in both clay and sandy soils treated with all tested pesticides. However, oxamyl had the lowest effect on dehydrogenase and phosphatase activities in both soil types compared to the other pesticides used in this study. Dehydrogenase and phosphatase activities in treated or untreated clay soil were higher than those in sandy soil. Additionally, the highest enhancement of dehydrogenase activity was observed at low concentrations of carbofuran and oxamyl, while a high concentration of ametryn and bentazone had a similar effect in both soil types. The highest stimulation of phosphatase activity was achieved at low pesticide concentration in clay soil, whereas high concentration was more effective in sandy soil. Based on the results obtained, it can be stated that the pesticide concentration, the soil type, and the incubation time are important factors affecting the pesticide-soil enzyme relationship. Accordingly, such a study can be used, which indicates the induction of such important enzymes in the soil, which can be used as an indicator to measure pesticide contamination in the soil within 60 days of exposure to pesticides. [ABSTRACT FROM AUTHOR]

Marginal sandy land is land that has limited nutrient content and low water holding capacity. One effort that can be made to increase the productivity of sandy land is by adding organic materials, VP3 biofertilizer pellets and Trichoderma Viride. This research aims to determine the effect of using planting media as residual biofertilizer pellets VP3 and Trichoderma viride FRP3 in sandy soil left over from soybean cultivation on the yield and growth of green mustard plants (Brassica juncea L.) as well as the effect on the chlorophyll content of green mustard leaves in the greenhouse. This research used a Randomized Group Design (RAK) consisting of 6 treatments. The parameters observed included plant height, number of leaves, leaf area, consumption weight, and leaf chlorophyll content. The results of the research showed that the use of biofertilizer pellet residue VP3 and Trichoderma viride FRP3 in sandy soil left over from soybean cultivation had a significant effect on the yield and growth of mustard greens compared to the control. And the residue of biofertilizer pellets VP3 and Trichoderma viride FRP3 in sandy soil left over from soybean cultivation has a significant effect on the chlorophyll content of green mustard leaves aged 7-21 HST. [ABSTRACT FROM AUTHOR]

The present study investigated glyphosate adsorption-desorption in Malaysian sandy soil exposed to burning or applied with cow dung or rice husk ash (RHA). One gram each of the adsorbents (control, burnt soil, soil + cow dung, soil + RHA) was separately and in replicate mixed with solution of 20 mL of glyphosate at different initial concentrations (0, 25, 50, 100, 150, 200, 250 and 300 mg L-1), shaken for 24 hours, centrifuged at 10, 000 rpm for 10 minutes and later the decanted supernatants were collected. Desorption study follow immediately through addition of 20 mL of 0.01 M CaCh solution and then treated like adsorption study. Glyphosate analysis was done using high performance liquid chromatography with fluorescence detector and isotherm data was fitted to linear, Freundlich, Langmuir and Temkin models. Freundlich best fits the adsorption of glyphosate and application of cow dung or RHA enhanced the soil affinity for glyphosate. Freundlich isotherm constant (KF) for soils treated with RHA and cow dung were 9.768 mg g-1 and 6. 751 mg g-1, respectively as compared to 3.189 mg g-1 for the control soil. However, the greatest KF value (387.238 mg g-1) was recorded by burnt Benta soil. Glyphosate adsorption by both control and treated soils was favourable (0.044 < RL < 0.3). This study suggests that adsorption occurred through physical processes involving diffusion, complexation or ligand exchange. Glyphosate desorption from soils treated with cow dung and RHA was either hysteretic or reversible. Burning this soil should be discouraged due to its effect on increasing glyphosate mobility and possible groundwater contamination. Meanwhile, agricultural waste can be applied to this soil even though it might lead to an increased glyphosate mobility but because of its potential positive effect on the soil's biological functions, the glyphosate ions are bound to be degraded. [ABSTRACT FROM AUTHOR]

This study examines the combined impact of pre-test curing and soaking periods on the soil's resistance to collapse those results from treating gypseous sand with varying amounts of nanoclay. The soil comes from the Iraqi city of Najaf. The soil sample is mainly sand. The nanoclay named "Montmorillonite K10" is used, and it is non-toxic. The tests are performed with a computerized Oedometer. The collapse potential is estimated according to a single Oedometer test (SOT), where the specimens are initially dry and then soaked under a stress level of 200 kPa. Four data sets related to the percentages of 0, 3, 6, and 12% nanoclay are used. Each data set comprises three groups of pre-tests for curing duration and different soaking durations. All experiments have a constant initial dry density of 1.64 g/cm3, water moisture of 3%, and gypsum content of 29%. The findings of this study show that the collapse potential (CP) of natural soil specimens decreases as the pre-test curing time increases. Generally, there is a decrease in CP due to adding the nanoclay and 6% of the nanoclay exhibited the highest reduction in CP. Also, there is an increase in the pre-test curing for the nanoclay-treated soil specimens, which leads to an increase in the CP related to the no-curing state. [ABSTRACT FROM AUTHOR]

A methodology combining physical experiments with simulation was employed to acquire contact parameters of sandy soil precisely for planting tiger nuts in the desert area of Xinjiang. The stacking angle under different parameter combinations was applied as a response value. Through the Plackett–Burman test, several factors that have a significant influence were determined. The steepest ascent test was conducted to establish the finest scope of values for these parameters. The stacking angle was considered the response variable, and non-linear tools were used to optimize these parameters for simulation. The findings showed that applying response surface methodology (RSM) resulted in a relative error of 1.24%. In the case of BP-GA, the relative error compared to the physical test value was 0.34%, while for BP, it was 2.18%. After optimization using Wavelet Neural Network (WNN), the relative error was reduced to only 0.15%. Results suggest that WNN outperforms the RSM model, and the sandy soil model and parameters generated using WNN can be effectively utilized for discrete element simulation research. [ABSTRACT FROM AUTHOR]

Cotton planting has widely used the mode of 'dry sowing and wet emergence' in the sandy soil of arid areas, particularly in southern Xinjiang, China. There are also soft and dry soil textures, as well as the residues of agricultural film. However, the continuous operation of spring tillage and soil preparation has seriously affected the emergence rate of cotton planting, such as the large working resistance, uneven seedling bed, and low pressure. In this study, a seedbed preparation machine was designed suitable for the sandy soil. The multiple operations were realized at one time, including crushing soil, leveling soil, stubble removal, pressing, and grinding. A segmented soil leveling device was also designed to replace the rake group for the joint preparation using the discrete element method (DEM). A two-stage type was then utilized to symmetrically distribute the first section of the scraper in a 'W' shape. The motion analysis was performed to explore the effect of the scraper angle on the soil fluidity, smoothness, and working resistance. Once the inclination angle of the scraper was 45°, better performance was achieved in the crushing soil and leveling soil. A bench orthogonal test was carried out to optimize the influencing factors of the diameter of the press roller, counterweight, and the diameter of the crushing roller in the machine soil layer construction device using the comprehensive scoring method. The construction of the soil layer was evaluated to compare the membership score and variance analysis of soil compactness, depth of repression, and tractive resistance membership degree. The results show that the significant influencing factors were found in the diameters of the press and crushing roller, and there was no influence of the counterweight. The optimal diameter of the press and crushing rollers was both 400 mm. The prototype test showed that the working resistance and fuel consumption were reduced by 8.67 % and 5.4 %, respectively, whereas, the operating efficiency increased by 6.6 %. The standard deviation of surface flatness was 2.8 % after two times of equipment preparation. The stability coefficient of tillage depth was 9.2 %, and the soil crushing rate was 92.3%, indicating no straw residual film on the surface. The segmented soil leveling device was used to effectively break the soil and stubble. The compaction degrees of 0-20, and 20-50 mm soil layer were 50-100, and 150-200 kPa, respectively. The floating soil layer construction device effectively compacted the soil to construct the soil layer structure of 'upper virtual and lower real'. The average soil compaction degree of the sowing soil layer was 169 kPa suitable for the precision sowing of film mulching and cotton growth in the sandy soil. The dislocation rate of seed film decreased by 62.5 %, whereas, the emergence rate was improved by 4.8 %, compared with the contrast model. The findings can provide a strong reference to develop the seedbed soil preparation for the cotton film planting in the sandy soil. [ABSTRACT FROM AUTHOR]

Sporobolus cryptandrus is a C4 perennial bunchgrass native to extensive areas of North America. As a non-native species, it has been reported from several continents, and it has been described as a transformer species in sand steppes of Central and Eastern Europe. However, its spreading ability across the landscape and within habitats has not been quantified, and factors determining its success have not yet been assessed. In this study, we focused on the largest stronghold of S. cryptandrus invasion in Hungary, where the species was first recorded in 2016, and investigated its present distribution in the landscape by mapping along dirt roads. In a separate local study in a heavily infested sand dune site of 2 km2, we assessed the infestation level and factors affecting the species' establishment. Our landscape-scale mapping found that in April 2023, the distribution of S. cryptandrus encompassed a largely contiguous 600 km2, with documented presence from 282 1-km2 mapping units. The species occurred more than 5 m away from roads in 71 mapping units, mostly in the centre of its distribution area. Sporobolus cryptandrus presence was negatively related to soil organic matter content and positively related to sand content. At the local scale, we found the species in 39% of vegetation plots in a sand dune site originally covered by Pannonic sand steppes, a priority habitat in the EU Habitats Directive. Sporobolus cryptandrus presence at this site was negatively related to the total cover of resident grassland but, surprisingly, was unrelated to the distance from roads. Collectively, these results suggest that primary spread occurs mostly along roads; these roadside populations likely serve as sources for establishment in neighbouring grasslands, but subsequent mass invasion becomes independent from roads. Together with the species' broad macroclimatic tolerance in North America and reported mass invasion events in Ukraine and Russia, our results suggest that S. cryptandrus likely poses a broad-scale threat to Eurasian dry grasslands, in particular on coarse-textured sandy soils with low vegetation cover. [ABSTRACT FROM AUTHOR]

Domesticated apple is a drought-sensitive species that spread from continental to Mediterranean temperate regions, where it can particularly experience prolonged water stress. One strategy to improve drought resistance in apple is engrafting on selected rootstocks. This study explores the potential of fast chlorophyll a fluorescence for the comparison of rootstock sensitivity to drought, looking for significant correlations with fruit productivity. The experiment was conducted in a field located in the coastal Po River Plain, Northern Italy, characterized by a loamy sandy soil, particularly prone to drought (86% sand). Mature plants of apple cv. Superchief® Sandidge engrafted on three different rootstocks (CIVP21pbr, MM106, M26) were monitored throughout the summer of 2021 and compared between irrigated and non-irrigated parcels, and at the end of the season, fruit production was evaluated. Despite soil water tension only reaching −13 kPa, the non-irrigated plants experienced a small but consistent loss of Photosystem II (PSII) activity and a lesser capacity of light energy conservation in the photosynthetic electron transport chain. The fruit weight correlated with PSII photochemical indexes recorded during early drought, particularly FV/FM and PIABS; a correlation emerged between fruit number per plant and median values of electron transport parameters, including PITOT. Although all rootstocks underwent a 40% loss of productivity, the fluorescence parameters revealed a graded susceptibility to drought, M26 > CIVP21pbr > MM106, which matched well with the plant vigour. The least drought-sensitive MM106 produced less numerous but heavier fruits than the other two rootstocks. [ABSTRACT FROM AUTHOR]

This research deals with modifying improvement techniques by using a new technology depending on the properties of the subsoil and the surrounding soil. Jet grouting is one of these techniques utilized instead of normal deep foundations, such as piles, peers, and raft foundations, because it increases the bearing capacity, reduces the settlement, and decreases permeability. In this research, the effect of double-pile and (2*2) jet column piles was studied in the laboratory by employing a jet grouting machine for sand soil, and the results were compared with those of similarly distributed concrete piles. Moreover, the two groups were theoretically analyzed with the 3D ABAQUS finite element software. It was found that with the jet pile, the applied load is greater and the settlement is smaller than that with the concrete pile. The ultimate pile ratio obtained through laboratory tests in the (2*1) jet pile and the concrete pile groups was 71.2% and 75%, respectively. The settlement ranged from 0.00135 to 0.00148 m with the jet pile and ranged from 0.034 to 0.035 m with the concrete pile. [ABSTRACT FROM AUTHOR]

This study investigates the impact of two different superabsorbant hydrogels (SAH) on the growth and development of fenugreek plants cultivated under sandy soil conditions. The hydrogels used in this study were (Polyacrylic acid and Vinyl alcohol sodium polyacrylate (and were applied with rates of 0.05, 0.1, 0.2, and 0.4% of the soil weight. The amended soil with SAH could improve the growth of fenugreek plants, and the enhancement level was simultaneous with the added hydrogel rate. Morphologically, the highest concentration (0.4%) of SAH treatments recorded the highest values of plant height, root lengths, fresh weights, and shoot and root dry weight. SAH enhanced water use efficiency by modulating relative water content (RWC) in plants compared to the control. Application SAH improved transpiration rates, stomatal conductance, Water use efficiency, Photosynthesis rate, and chlorophyll contents compared to non-treated. In contrast, antioxidant enzyme activities Superoxide dismutase (SOD), peroxidase (POD), Ascorbate peroxidase (APX), Catalase (CAT), protein contents, carbohydrate content, amino acids, and proline content were decreased when SAHs were applied as the plant was still far from the wilting point. This study shows that applying SAH in newly reclaimed desert soils was advantageous for those who had suffered from water shortage conditions.

To explore the mechanism of freeze–thaw cycles on the nutrient release of soft rock and sand-remodeled soils in Mu Us Sandy land of China, and to clarify the adaptation potential of remodeled soils with different proportions to extreme environment, indoor freezer simulation freeze–thaw experiments were carried out. The research results show that during the 2 cycles of freeze–thaw, the remodeled soil organic matter content and total nitrogen content (TNC) of the three treatments reached their peaks. Compared with that before freezing, T1, T2, and T3 treatments increased TNC by 40.9, 90.2, and 118.9%. The freeze–thaw cycle has a significant impact on the emergence rate of maize (P < 0.05). In the soil during the 2 freeze–thaw cycles, the seedling emergence rate of maize is the highest. Compared with non-freeze–thaw treatment, the maize emergence rate of T1, T2, and T3 treatments was increased by 2, 3, and 3 times, and the emergence rate of T2 and T3 treatments was higher than that of T1 treatments under different freeze–thaw cycles. In conclusion, short-term freeze–thaw cycles can promote soil carbon and nitrogen mineralization and improve nutrient availability in Mu Us Sandy land, and T2 and T3 treatments have better adaptability to the environment.

Imidacloprid (IDP) products are applied via soil drenching in the citrus critical root zone (CCRZ) at 0–60 cm soil depth. This study aimed to determine the uptake and leaching of IDP in the CCRZ of a Florida Entisol. The treatments include: (1) a control with no IDP applied, (2) 1.6 g of active ingredient (a.i.) per tree (×2), and (3) 3.2 g a.i. per tree of IDP (×4). The treatments were applied to two trees within each experiment unit, replicated five times, and completely randomized. The IDP concentration in the Entisol was affected by the amount of water received within the sampling intervals. IDP movement in the Entisol was evident for the field trials in Fall 2021 and 2022, irrespective of the treatment. A total of 10 mm of daily irrigation was the major driver of IDP movement in Fall 2021 (September–December 2021), while 11.7 cm of cumulative rainfall plus 10 mm of daily irrigation were the major drivers for IDP in Fall 2022 (November–December 2022). The IDP uptake level by leaves was relatively low probably because of the relatively low temperature and humidity. More applications of IDP did not result in its higher uptake by citrus leaves in the Entisol. Given the persistence of IDP, there is a possibility of leaching, which could potentially contaminate the groundwater, surface water, and non-target organisms. Therefore, it is crucial to carefully manage the use of IDP in citrus production systems to mitigate the unintended environmental impacts.

This research studies geogrid reinforcement of sandy soils under the influence of the three earthquakes (Halabjah, Bolunun, and Ali Al-Gharbi) due to the recent increase in seismic activity and the need to reduce damage to foundations due to settlement. Sand samples prepared with a relative density of 70%, with and without geogrid reinforcement, were tested on a shaking (vibrating table) table. Five geogrid layers were used, respectively. Settlement occurs due to dynamic force, and the plastic foundation was used with dimensions of 100 * 100 * 30 mm. Withstands a static load of 5.294 kN/m2. Increasing the acceleration of the earthquake leads to an increase in the settlement of the foundation in the sandy soil. The greater the number of geogrids reinforcing layers, the leads to a decrease in the base settlement, where the rate of settlement decrease is greater, the lower the earthquake acceleration and the greater the number of geogrid reinforcement layers. The time of onset of settlement and the general pattern of settlement are similar in all cases studied. The rate of settlement is approximately twice as high when the soil is saturated than when the soil is dry, and the effect of geogrids is less for the soil when it is saturated than when it is dry.

Microplastic pollution is an emerging concern and poses a potential risk to soil ecosystems and subsequently can lead to groundwater contamination. The sandy and silty soils are the major soil types covering more than 31 % of the land area globally. The vertical transport of microplastic in sandy and silty soil and further possible groundwater contamination is still unclear and not fully understood in the literature. The present study focuses on the movement of High-Density Polyethylene (HDPE) microplastics in quartz sand and silty soil using column experiments. Detailed flow through laboratory experiments are performed to understand the effect of varying the critical parameters in contaminant transport such as pore volumes (1PV,2PV,3PV,4PV,5PV,6PV,7PV,8PV,9PV,10PV) and flow rates (20,40,60,80,100,120 ml/min) on HDPE microplastic movement in sandy and silty soil separately. The maximum depth of microplastic transport in sandy soil was 20-22 cm for a flow rate of 120 ml/min, and 10-12 cm for 20 ml/min. In silty soil, the maximum depth of microplastic transport was 12-14 cm for 120 ml/min and 6-8 cm for 20 ml/min. The study also estimates the number of years required for microplastic contamination to reach groundwater under field conditions by considering the L/S ratio. The study estimated that it could take 144 years for microplastics to penetrate sandy soil and 356 years for silty soil, under the study conditions. The study highlights the significant threat posed by microplastics to groundwater contamination. The results suggest that soils may serve as both a sink for microplastics and a potential pathway for their entry into subsurface environments, such as underground habitats and water sources.

Detecting and determining the development of the frozen wall is a vital component of artificial freezing engineering. The electromagnetic parameters of frozen soil play a critical role in the fast and accurate identification using high-frequency electromagnetic waves. This study investigated the impacts of various factors on the dielectric properties of artificial frozen soil through laboratory experiments. The dielectric properties and evolutionary characteristics of sand were measured under different conditions, including temperature, probing frequency, initial moisture content, and salt content. The experimental results obtained characteristic curves of the relative dielectric constant of frozen sand in the frequency range of 300–2000 MHz under various conditions. Quantitative analysis was conducted to examine the differences in the dielectric properties of frozen sand. The analysis indicated that, under low-temperature and salt-free conditions, a reflection coefficient above 0.464 can be utilized to identify frozen/unfrozen sand. Furthermore, ground penetrating radar (GPR) is capable of effectively detecting and differentiating between salt-containing unfrozen soil and frozen soil. This study provides a solid theoretical framework for the quantitative identification of freezing front and frozen wall development. Additionally, the research findings have substantial theoretical implications for defect detection in frozen walls and the quantitative inversion of temperature fields in frozen soil. [ABSTRACT FROM AUTHOR]

Introduction: Phosphorus (P) fertilizer is critical to maintain a high yield and quality of alfalfa (Medicago sativa L.). There are several fertilizer types and soil types in China, and the application of a single type of P fertilizer may not be suitable for present-day alfalfa production. Methods: In order to select the optimal combination of alfalfa and soil type and fertilizer type for improving P utilization efficiency. We conducted a greenhouse pot experiment, calcium superphosphate (SSP), diammonium phosphate (DAP), ammonium polyphosphate (APP), potassium dihydrogen phosphate (KP), and no-fertilizer control treatments were applied to alfalfa in sandy and saline-alkali soils. The response of alfalfa root morphology and rhizosphere processes to different P fertilizers was investigated. Results and discussion: The results showed that shoot biomass of alfalfa was slightly higher in sandy soil than in saline-alkali soil. Shoot biomass of alfalfa increased by 223%-354% in sandy soil under P treatments compared with the control, and total root length increased significantly by 74% and 53% in DAP and SSP treatments, respectively. In saline-alkali soil, alfalfa shoot biomass was significantly increased by 229% and 275% in KP and DAP treatments, and total root length was increased by 109% only in DAP treatment. Net P uptake of alfalfa in DAP treatment was the highest in both soils, which were 0.73 and 0.54 mg plant-1, respectively. Alfalfa shoot P concentration was significantly positively correlated with shoot and root biomass (P < 0.05, 0.01 or 0.001) whereas negatively correlated with acid phosphatase concentration (P < 0.05). Improvement of plant growth and P uptake induced by P fertilizer application was greater in sandy soil than in saline-alkali soil. DAP and KP was the most efficient P fertilizers in both sandy soil and saline-alkali soil. [ABSTRACT FROM AUTHOR]

Bare land, as a significant land cover type on the Earth's surface, plays a crucial role in supporting land-use planning, urban management, and ecological environmental research through the investigation of its spatial distribution. However, due to the diversity of land-cover types on the Earth's surface and the spectral complexity exhibited by bare land under the influence of environmental factors, it is prone to confusion with urban and other land features. In order to extract bare land rapidly and efficiently, this study introduces a novel bare land extraction index called the Bare Land Extraction Index (BLEI). Then, considering both Ganzi Tibetan Autonomous Prefecture and Urumqi, China as the study areas, we compared BLEI with three presented indices: the Bare-soil Index (BI), Dry Bare Soil Index (DBSI), and Bare Soil Index (BSI). The results show that BLEI exhibits excellent efficacy in distinguishing bare land and urban areas. It gets the most outstanding accuracy in bare land identification and mapping, with overall accuracy (OA), kappa coefficient, and F1-score of 98.91%, 0.97, and 97.89%, respectively. Furthermore, BLEI is also effective in distinguishing bare land from sandy soil, which can not only improve the mapping accuracy of bare land in soil-deserted areas but also provide technological support for soil research and land-use planning. [ABSTRACT FROM AUTHOR]

Soil organic carbon (SOC) plays a significant role in climate change. Its content can be modified by soil management practices, however, the effect of mineral fertilization on SOC is not clear. For this reason, a long-term effect of gradually increasing rates of NPK fertilizers on changes in soil organic carbon (SOC) in bulk soil and in water-stable aggregates (WSA) in soils with sandy loam and loamy sand texture at two experimental sites (Skierniewice, Poland, and Dražovce, Slovakia) was quantified. In both sites, soil samples were collected from the following treatments: NF – no fertilization, NPK1 and NPK2 – 1st level and 2nd level of NPK fertilization, respectively. The results showed that 100-year long application of NPK1 increased total carbon (TC) and SOC content by 24%, while NPK2 decreased it by 5% compared to NF at the Skierniewice site. The content of water-stable macroaggregates (WSAma) increased because of NPK application. In NPK1, the content of WSAma was higher and the content of water-stable microaggregates (WSAmi) was lower than in NPK2 or NF. However, as a result of NPK application, the content of agronomically favorable WSAma in size fraction 0.5–3 mm was reduced by 8 and 24% in NPK1 and NPK2, respectively, compared to NF. Overall, SOC in WSAma was lower than in bulk soil. The SOC in WSAma in NF, NPK1 and NPK2 treatments was 6.51, 7.77 and 5.89 g.kg−1, respectively. Similar tendency of SOC in WSAma 0.5–3 mm was observed (NF: 6.12 g.kg−1, NPK1: 7.35 g.kg−1, and NPK2: 6.88 g.kg−1). The SOC in WSAmi in NF, NPK1 and NPK2 was 8.33, 7.39 and 7.24 g.kg−1, respectively. At Dražovce site, TC content decreased significantly due to the graded rates of NPK, not because of SOC mineralization but as a result of carbonate dissolution for a period of 14 years. The carbonate content decreased from 20 g.kg−1 in NF to 6.5 g.kg-1 in NPK1 and 3.0 g.kg-1 in NPK2, while SOC did not change significantly: (NF: 23.8 g.kg−1, NPK1: 25.9 g.kg−1, and NPK2: 23.4 g.kg−1). In NPK1, the WSAma content was reduced significantly when compared to NPK2 and NF treatments. No significant difference was observed between NF and NPK2. On the contrary, the content of WSAma 0.5–3 mm significantly increased when compared to NF and NPK1. No difference was observed between NF and NPK1. Lower SOC content was found in WSA than in the bulk soil. Overall, higher SOC content was observed in WSAma when compared with WSAmi. The application of NPK1 and NPK2 increased SOC in WSAma as well as in WSAma 0.5–3 mm. The effect was more significant in NPK1 than NPK2 treatments when compared to NF. [ABSTRACT FROM AUTHOR]

Due to the loose structure and low cohesion of natural sand, many improved techniques have been tried to overcome this deficiency. When fiber reinforcement technology is applied to reinforce sand, there are deficiencies such as low cohesion and limited strength improvement effect. This paper studies the effect of xanthan gum (XG) for the improved fiber reinforcement technique. Biopolymers are popular in soil improvement as an environmentally friendly alternative. Unconfined compressive strength (UCS) tests, direct shear tests, and Brazilian splitting tests were performed to investigate the effect of different XG content and drying times on the mechanical properties of fiber-reinforced sandy soils treated with XG. The scanning electron microscope (SEM) was used to investigate the microstructure of the materials. The test results show that the extension of drying time and the increase of XG content have a positive effect on strength and the optimal content of XG is 4% for UCS and 3% for tensile strength and shear strength. The maximum UCS and elastic modulus are 4829 kPa and 171.65 MPa, respectively, the maximum shear strength, cohesion, and tensile strength can be increased to 938.9 kPa, 620 kPa, and 807 kPa, respectively, and the optimal drying time is 14 days. SEM analysis showed that the XG enhanced the strength by filling the pores between the particles, adhering to the surface of the soil particles and the fiber mesh, increasing the roughness and interlocking force of fibers. The conclusion shows that XG, as an environmentally friendly improvement material, has a great effect on improving the strength of soil and can provide a solution to solve the deficiency of fiber reinforcement technology and improve its application in sandy soil. [ABSTRACT FROM AUTHOR]

Helical piles are advantageous alternatives in constructions subjected to high tractions in their foundations, like transmission towers. Installation torque is a key parameter to define installation equipment and the final depth of the helical pile. This work applies machine learning (ML) techniques to predict helical pile installation torque based on information from 707 installation reports, including Standard Penetration Test (SPT) data. It uses this information to build three datasets to train and test eight machine-learning techniques. Decision tree (DT) was the worst technique for comparing performances, and cubist (CUB) was the best. Pile length was the most important variable, while soil type had little relevance for predictions. Predictions become more accurate for torque values greater than 8 kNm. Results show that CUB predictions are within 0.71 , 1.59 times the real value with a 95% confidence. Thus, CUB successfully predicted the pile length using SPT data in a case study. One can conclude that the proposed methodology has the potential to aid in the helical pile design and the equipment specification for installation. [ABSTRACT FROM AUTHOR]

Sandy areas occupy a huge amount of land worldwide, but due to their characteristics, they are mostly low in fertility and low in organic matter. Sandy soils have coarse texture, high saturated hydraulic conductivity, low soil organic carbon, and poor aggregate stability and water retention capacity; therefore, it is necessary to add organic additives to them. The objective of this study was to assess the effect of particle size and application rate of biochar (BC) produced under different pyrolysis temperatures on the porosity P, available water content for plants AWC, saturated hydraulic conductivity Ks, and contact angle CA of sandy soil. The results show that an application of BC to sandy soil significantly increased AWC by 76–168%, CA by 252–489%, P by 6–11%, and significantly reduced Ks by 37–90%. Statistical analysis of the effect of three examined factors (BC application rate, particle size, and pyrolysis temperature) revealed that P, AWC, and Ks were affected by all three factors, while CA was affected only by BC application rate and particle size. The statistically significant interaction between the two factors was found for P (temperature × rate and size × rate), AWC (temperature × size), and Ks (size × rate). Statistically significant interaction among the three factors was not found for any hydrophysical parameter. The application of BC to amend sandy soils can be seen as a strategy to mitigate drought conditions and to reduce the amount of irrigation, saving water. Further investigations are needed with regard to the BC application under climate conditions with long hot and dry periods, which may promote soil water repellency. [ABSTRACT FROM AUTHOR]

The safety of the geotechnical environment around subways is vitally important for their sustainability. Ground settlement is a very common threat to the safe operation of subways and is related to subway traffic vibrations. Taking Nanjing subway line 10 as an example, field tests, discrete element simulations, and a grey relational analysis are carried out to study the deformation mechanism of the underlying sandy soil induced by vibrations. The results show that the vibration load of Nanjing subway Line 10 is mainly concentrated in the vertical direction. The particles' coordination number below the subway increases under the vibration load, while the coordination number on the side of the tunnel decreases, which may cause a shear dilatancy effect. Among the five microscopic indexes, the local porosity and the coordination number are closely related to the deformation. Although the deformation of the underlying sandy soil is quite small under the subway traffic load, it will accumulate under frequent loading and then lead to urban engineering geological disasters. [ABSTRACT FROM AUTHOR]

More than half of the forest area of the North German Lowlands is stocked with Scots pine-dominated forests, mostly plantations. Climate change suggests a declining suitability of Europe's temperate zone for conifer plantations, but only a few studies have examined the long-term growth trends of Scots pine in relation to environmental and site factors in this region. We studied the radial growth patterns of Scots pine over the last 60 years at ten sites along a precipitation gradient (830–530 mm mean annual precipitation) from an oceanic to a subcontinental climate, analyzing the spatial and temporal variability of the climate sensitivity of growth to identify the main climatic factors influencing pine growth across this gradient, which covers a large part of the species' tolerated precipitation range. Annual radial increment was sensitive to late-winter temperatures (February, March) and summer drought and heat (June–August), with sensitivity increasing from the oceanic to the drier continental sites. Warmer late-winter periods apparently have stimulated growth during the last decades, while the sensitivity to summer-drought has remained fairly stable. Until recently, the negative impact of warming summers on growth has been compensated by the positive effect of late-winter warming, resulting in stable (or increasing) growth trends. However, our comparison of the climate sensitivity across sites suggests that the drought effect compensation through winter warming will in future be limited by increasing drought exposure. Thus, future productivity declines are likely in the northern German lowlands despite warming winters, discouraging large-scale pine plantations in the face of climate warming. [ABSTRACT FROM AUTHOR]

Water and sand leakage disasters are likely to occur during construction in water-rich sand layer areas, resulting in ground collapse. The stress-strain action characteristics of discontinuous graded sand under different internal erosion degrees, and the evolution mechanism of water and sand leakage disasters caused by the internal erosion need to be further explored. Therefore, this paper takes the discontinuous graded sand in a water rich sand layer area in Nanchang City of China as the research object. Considering the influence of different fine particle losses (0, 10%, 20% and 30%) under the internal erosion of sand, the salt solution method is used to realize the specified loss of fine particles in the internal erosion. The stress-strain behavior after the loss of fine particles due to internal erosion is studied by triaxial shear test. Meanwhile, the physical model test and PFC-CFD method are both used to study the evolution rules of water and sand leakage disaster considered the influence of internal erosion degrees. Results show that: (1) under the same confining pressure, the peak failure strength of sand samples decreases along with the increase of fine particle loss. (2) In the water and sand leakage test of saturated sand, a natural filter channel is formed above the observed soil arch. The greater the loss of fine particles, the steeper and wider the collapse settlement area. (3) The relationship between the cumulative amount of water and sand leakage and time is nonlinear. The total mass loss of sand increases along with the increase of internal erosion degree. (4) After the soil arch is formed around the damaged opening, the sand continues to converge above the soil arch under the action of water flow, resulting in the dense convergence of contact force chains. [ABSTRACT FROM AUTHOR]

Visible-Near Infrared (vis-NIR) spectroscopy can provide a faster, cost-effective, and user-friendly solution to monitor leaf N status, potentially overcoming the limitations of current techniques. The objectives of the study were to develop and validate partial least square regression (PLSR) to estimate the total N contents of fresh and removed leaves of potatoes using the vis-NIR spectral range (350–2500 nm) generated from a handheld proximal sensor. The model was built using data collected from Hancock Agricultural Research Station, WI, USA in 2020 and was validated using samples collected in 2021 for four different conditions. The conditions included two sites (Coloma and Hancock), four potato varieties (Burbank, Norkotah, Goldrush, and Silverton), two N rates (unfertilized and 308 kg N ha−1), and four growth stages (vegetative, tuber initiation, tuber bulking, and tuber maturation). The calibration and validation models had high predictive performance for leaf total N with R2 > 0.8 and RPD > 2. The model accuracy was affected by the total N contents in the leaf samples where the model underpredicted the samples with total leaf N contents greater than 6%. [ABSTRACT FROM AUTHOR]

CLIMATE change is one of the most important global issues that impacts all our life sides. Growing crops and their productivity also are influenced by changing in the climate and climatic elements. Growing tea in non-traditional regions like Egypt could be considered a challenge due to the specific climatic and soil requirements for growing and production. However, with careful planning and experimentation, it might be possible to establish tea cultivation in such conditions. So, a lysimeter trial was conducted as an exploratory experiment aiming to assess tea cultivation performance in both sandy and clayey soil. Additionally, a separate field trial was carried out to evaluate tea growth in clayey soil along with applied organic fertilizer (chicken manure). The findings revealed that, under the lysimeter trial, tea plants exhibited robust growth on both sandy and clayey soil. Various parameters, including plant height, fresh and dry weights, leaf area, chlorophyll content, and leaf N, P, K levels, indicated superior performance on sandy soil compared to clayey soil. In the field trial, notable superiority was observed in plants grown on the organic medium containing chicken manure over those plants grown on clayey soil without such supplementation. These outcomes suggest that climate changes could potentially transform Egypt into a favorable region for tea cultivation. More studies are needed to establish a complete program of cultivation of tea including the water and nutrient requirements. [ABSTRACT FROM AUTHOR]

The microscale mechanisms underlying the suction anchor–sandy soil interaction under slidable pulling actions of mooring lines remain poorly understood. This technical note addresses this knowledge gap by investigating the suction anchor–sandy soil interaction from micro to macro, with a particular emphasis on the effect of interface friction. The discrete element method (DEM) was utilized to simulate the sandy soil, while the finite element method (FEM) was employed to model the suction anchors. The peak pulling forces in numerical simulations were verified by centrifuge test results. The research findings highlight the significant influence of interface friction on the pulling force–displacement curves, as it affects the patterns of suction anchor–sandy soil interactions. Furthermore, clear relationships were established between the magnitude of interface friction, rotation angle, and pullout displacement of suction anchors. By examining the macro-to-micro behaviors of suction anchor–sandy soil interactions, this study concludes with a comprehensive understanding of failure patterns and their key characteristics under different interface friction conditions. The findings proved that the interface friction not only influences the anti-pullout capacity but also changes the failure patterns of suction anchor–soil interactions in marine engineering. [ABSTRACT FROM AUTHOR]

The influence of the quantities and ratios of dissolved organic carbon (DOC) and dissolved nitrogen (DN) generated by different chemical quality classes of organic residues on soil microbial processes in the decomposition process is not well understood. If the DOC-to-DN ratio (hereafter, ratio) of the substrate is close to that of the microbial C-to-N ratio, then the DOC-and-DN stoichiometry of the substrate is balanced, resulting in enhanced microbial processing, i.e., carbon use efficiency (CUE). Uncertainty exists about the influence of DN and the DOC-to-DN ratio on CUE, particularly in high-quality class (high nitrogen) residue-treated soils. A long-term field experiment was used to explore the effect of the annual application of residues of different quality classes on decomposition processes, focusing on the effects of DOC, DN, and the ratio on the microbial metabolic quotient (qCO2), which is the inverse of CUE. DOC and DN were extracted from soils during the 13th year of the experiment. Soils treated with high-quality class groundnut residue (high-nitrogen) had higher DN (5.4 ± 2.6 mg N kg−1) and a lower ratio (6.8 ± 2.6) than those treated with medium-quality (medium-nitrogen) tamarind (3.0 ± 0.6 and 10.7 ± 2.2, respectively). The positive influence of DN on qCO2 (R2 = 0.49 *) in groundnut-treated soil suggested that the high bioavailability of DN reduced CUE due to imbalanced DOC-and-DN stoichiometry. This contradicted earlier published findings on high-nitrogen residues which had balanced DOC-and-DN stoichiometry. The positive influence of the ratio on qCO2 under the tamarind-treated soil (R2 = 0.60 *) indicated that its balanced DOC-and-DN stoichiometry enhanced CUE. High-quality class organic residues can result in either higher or lower CUE than their lower-quality class counterparts depending on whether the resulting DOC-and-DN stoichiometry is balanced or imbalanced. [ABSTRACT FROM AUTHOR]

To reduce plant-parasitic nematodes (PPNs), an alternative solution based on amendments from selected native shrub was used to favor mainly the increase of free-living nematodes (FLNs) that include high trophic (bacterivorous, fungivorous, omnivorous, and carnivorous) nematodes and influence soil microbial activities. The consequences of the subsequent reduce of PPNs of the soil were also determined. Experiments were performed in a shade house using six treatments consisting of shrub residues from Piliostigma reticulatum (Pil), Boscia senegalensis (Bos), and Crotalaria juncea (Cro); a Straw-based Compost (Cs); a Farmer practice (FP) using Nitrogen-Phosphorus-Potassium (NPK) fertilizer; and a control (C0, no amendments). Abundances of nematodes, trophic groups, and nematodes ecological indices were determined. Enzymatic activities (ß-glucosidase and acid phosphatase) and the fluorescein diacetate hydrolysis (FDA) were also determined. Soil amended by Bos and Cro increased the density of nematodes compared to control soil or amended with NPK fertilizer. Indices of taxonomic diversity (H') did not differ significantly between the treatments. However, soils amended with Bos and Cro had the highest enrichment index (EI), and the lowest Nematode Channel Ratio (NCR), indicating that these two shrub residues exhibited a higher food web in response to the available resources provided by the fungal decomposition pathway. Moreover, Bos favored omnivorous and increased enzymatic activities. Bos induce 'bottom-up' while Cro induce 'top-down' controls on nematode populations. [ABSTRACT FROM AUTHOR]