Sandy Clay Research Articles

Mineral Nitrogen Release Patterns in Various Soil and Texture Types and the Impact of Urea and Coated Urea Potassium Humate on Barley Biomass

Controlled-release urea fertilization is an innovative approach and effective means to reduce the loss of nitrogen and enhance fertilizer use efficiency to optimize crop yield while minimizing the environmental impact. The objective of this study was to investigate the dynamic process of mineral nitrogen (Nmin) release in Luvisols, Cambisols, Retisols, and Arenosols to understand the interaction between soil characteristics and mineral nitrogen release and evaluate the impact of conventional urea compared to coated urea potassium humate on barley biomass production. A pot experiment was conducted under glasshouse conditions (20 ± 2 °C and 60% Humidity). Five treatments including no fertilization as a control (C), 100 kg·N·ha−1 of urea (U100), 200 kg·N·ha−1 of urea (U200), 100 kg·N·ha−1 of coated urea potassium humate (UPH100), and 200 kg·N·ha−1 of coated urea potassium humate (UPH200) were applied to four soil and texture types. Our findings indicate that there are different patterns of mineral nitrogen release across the different soil and texture types. Ammonium levels reached their peak point in all soils within 2–7 days after application. On the other hand, the concentration of nitrate NO3−–N showed a linear increase over 45 days during the experiment. The Retisol, which had a sandy clay texture, obtained the highest concentration of mineral nitrogen in both forms (NH4 and NO3), while the sandy texture of Arenosol showed the lowest accumulation of mineral nitrogen and its forms. The application of potassium humate caused a delay of 1–4 days in the peak of soil ammonium, which at peak accounted for approximately 25–44% of the mineral nitrogen in the soil. Furthermore, the application of urea and coated urea potassium humate exhibited significant effects on barley biomass with an increase of approximately 14–91% compared to the unfertilized treatment (control). This research contributes to our understanding of nutrient dynamics in diverse soil environments and provides insights into optimizing sustainable fertilization strategies such as controlled-release fertilizer application. The implications of these findings highlight the significance of tailored nutrient management practices based on soil texture type, which can lead to improved agricultural productivity and environmental impact.

Assessing soil health in a thermic region of the southern great plains, using the soil management assessment framework (SMAF)

The soil management assessment framework (SMAF) has been widely used as a tool to quantify soil health. However, SMAF was developed using data from only a few climate conditions in the United States and regional verification is often suggested. We evaluated SMAF's short-term performance in a thermic/hyperthermic region, aiming to 1) evaluate the sensitivity of SMAF scores to changes in individual soil properties and 2) quantify soil health changes using SMAF. Treatments include two levels of summer crop and two levels of tillage in an annually planted wheat system. SMAF soil health metrics were measured for Burleson clay soil (BC site) and Parrita sandy clay loam soil (PSCL site) for 0–5 cm soil depth. At the BC site, βgluc and SOC SMAF scores displayed no statistical differences when compared to their respective soil properties. βgluc measurement also helped to highlight the treatment difference observed for wheat yield. This suggests that scoring curves of βgluc used in SMAF may need to be modified, especially for clayey soils. The results also show that SMAF scores were not correlated with wheat yield at both sites, suggesting that multiple year data may be needed to understand this relationship. Overall, in a thermic region, SMAF was found to be helpful to understand short-term soil health status. However, due to clay correction in SMAF algorithm, SMAF scores can show lower sensitivity in the clayey soils of these thermic regions.

Growth response of clonal eucalyptus to varying levels of iron application and soil texture

Deficiency symptoms of iron (Fe) appear in eucalyptus (Eucalyptus spp.) plantations grown on different type of soils in Punjab, India. Therefore, a pot experiment was conducted to study the response of eucalyptus to application of Fe in soils of different textures. The treatments comprised of six levels of Fe as soil application (0, 15, 30, 45, 60, and 75 mg Fe kg−1 soil applied as chelated Fe through Fe-EDTA) and two foliar sprays (0.5% and 1% FeSO4·7H2O) replicated thrice in soils of three textures (loamy sand, sandy loam, and sandy clay) in a completely randomized design. Plant growth parameters, Fe concentration in soils, and Fe uptake by different plant parts were determined after nine months of eucalyptus growth. These parameters were significantly and positively influenced with the application of Fe. Dry weight of shoot and root was the highest at 30 mg Fe kg−1 whereas Fe concentration and uptake of Fe by shoot and root were the highest at 45 mg Fe kg−1. With 1% spray, the root dry weight, Fe concentration in leaves and its uptake by leaves and shoot were the highest. Loamy sand soil exhibited maximum shoot biomass and uptake response to applied Fe by eucalyptus. The Fe concentration in soil was positively and significantly related to Fe concentration (r = 0.436*–0.772**) and its uptake (r = 0.643**- 0.866**) by different plant parts. Conclusively, application of Fe to eucalyptus significantly increased the growth parameters, its uptake and response by the plants.

Riscos potenciais de erosão do solo no centro-norte do Vietnã usando sensoriamento remoto e GIS

ABSTRACT Unsustainable exploitation activities (UEAs), combined with the increasing impacts of global climate change are the key causes that lead to soil erosion in the North-Central Vietnam. Mountainous areas in the North-Central Vietnam commonly have steep slopes and sandy clay in the surface soil layer, which contribute to enhancing the soil erosion, resulting in a serious loss of life and property. This study investigates the land cover change (LCC) across the Thanh Chuong district by combining Remote Sensing Technique (RST) data with Geographic Information System (GIS) and further, establishing erosion risk hazard maps based on the RUSLE model simulation. To achieve these objectives, Sentinel and Landsat satellite images from the period 2010_2021 were acquired. It was verified that the forest area gradually decreased from 2010_2021, and the average annual soil loss was approximately 25 t per year. The amount of erosion that led to a soil loss of up to 18% of the total land area is related to weather conditions, terrain features, and the soil texture. The decline in the vegetation cover is expected to be the main cause of increasing trends in erosion and soil loss.

Compressibility behavior of conditioned sandy clay considering the physical degradation of foam: tunneling issue

Compressibility behavior of conditioned sandy clay considering the physical degradation of foam: tunneling issue

Response of Cow pea (Vigna unguiculata L.) to seeds rate and Foliar spray of Ca Nanoparticles

Field experiment conducted at summer in two season 2020-2021 and 2021-2022 on clay sandy soil in Al-Diwanyia. The experiment was design as Complete randomized block designing with three replications arranged for split-pilot design, and Lest Significant Deference's( LSD) 0.05 the main treatment contend two groups seeds rate 25 and 50 Kg ha-1 within there four levels of Nano Ca( 0 , 30 , 60 , 90) PPM I took sample of soil before planting to analysis it and to learn physical and chemical properties table 1. Cowpea( Vigna unguiculata L.) were sowing at two rates 25 and 50kg.ha-1(3 cm depth) at 1/4 , after 7 months I took a samples to measure . The results showed all factors and interactions were significant effect and increased all growth traits (plant height, number of leaves per plant and stem diameter , plant content of protein , carbohydrate total Chlorophyll and fats and active substances ,) lead to increased grain yield max values (2.72 Ton.ha-1) at interaction of 25 seeds rate and 90 ppm Ca Nanoparticles level, while min value(1.9 Ton.ha-1) at interaction 50 seed rate and 0 ppm Ca Nanoparticles level.

Comparative Investigation of Cd Adsorption on Alkaline Sandy Clay Loam Soil Treated with Cerium Oxide Nanoparticles, Organic and Inorganic Amendments

Comparative Investigation of Cd Adsorption on Alkaline Sandy Clay Loam Soil Treated with Cerium Oxide Nanoparticles, Organic and Inorganic Amendments

Fertility Status of Soils of Patuakhali Science and Technology University in Bangladesh

Soil is a heterogeneous body and different soil have different fertilizer requirement for crop production depending on fertility status. This research work was conducted to evaluate the fertility status of the soils of the research field of Patuakhali Science and Technology University (PSTU). The soils of PSTU were collected and analyzed for the determination of following soil parameters viz. particle size distribution, texture, pH, organic matter, total nitrogen, available phosphorus, available sulphur and exchangeable potassium. The results showed that the particle size distribution of the collected soils varied significantly with each other. A remarkable variation was observed in textural classes of the soils. The textural classes of the soils were sandy loam, clay and clay loam. The soils were neutral to slightly alkaline in reaction and the pH ranged from 7.01 to 7.73. The organic matter content was very low and ranged from 0.50 to 0.96%. The soils were found to be deficient in total nitrogen with a range of 0.06 to 0.11%. The available phosphorus, available sulphur and exchangeable potassium content of collected soils ranged from 8.76 to 15.90 ppm, 1.04 to 3.06 ppm and 0.12 to 0.26 meq/100 g soil, respectively. The fertility status of the soils was very low to medium level due to very low organic matter content.

Effect of Throttle Position and Gear Selection on Specific Energy Requirement and Power Utilization Efficiency of a Tractor Drawn Rotavator in Sandy Clay Loam Soil

Effect of Throttle Position and Gear Selection on Specific Energy Requirement and Power Utilization Efficiency of a Tractor Drawn Rotavator in Sandy Clay Loam Soil

Characteristics of soils for civil engineering foundations in part of North Central Nigeria, using electrical resistivity method

A geophysical investigation was carried out using Vertical Electrical Sounding (VES) in part of North Central Nigeria to evaluate the subsoil thickness, competence, and corrosivity for civil engineering foundations. A total of 60 VES stations were covered within the study area using the Schlumberger configuration array with half current electrode separation (AB/2) varying from 1m to a maximum of 100m while the half potential electrode spacing (MN/2) varied by 0.3 m to a maximum of 5m. The analysis of data was done using IP2win and Surfer 12 softwares. The first layer has resistivity values between 4.728 Ωm to 4210 Ωm and varied in thickness between 0.15 m to 1.42 m, the second layer has resistivity values between 24.7Ωm to 355000 Ωm and varied in thickness between 0.0355 m to 8.983 m while the third layer has resistivity values ranging between 8.361 Ωm to151,608 Ωm and varied in thickness between 1.05 m to 34.2 m, the fourth layer which is the last of the geoelectric layers has resistivity values between 27.95 m to 77000 m. The subsoil within the study area is composed of clay, sandy clay, clayey sand, sand, and laterite. From the qualitative interpretation of the Isoresistivity and Isopach maps, the Southwestern, Southeastern and Northwestern parts of the study area are moderately corrosive to extremely corrosive subsoil with resistivity values ranging between 4.728 Ωm and 50.48 Ωm. The third layer consists of an incompetent low resistivity soft material that underlain the entire study area except at the central region which is essentially noncorrosive and highly competent. VES curves interpretations revealed the thickness and depths of the geoelectric layers within the study area. The results of this research could enable civil engineers to ascertain the requisite depth of soil evacuation for the sustainability of structures within the study area.

Coupld thermo-hydraulic modelling of heat storage in an embankment

Coupld thermo-hydraulic modelling of heat storage in an embankment

Response of Cow pea (Vigna unguiculata L.) to seeds rate and Foliar spray of Ca Nanoparticles

Field experiment conducted at summer in two season 2020-2021 and 2021-2022 on clay sandy soil in Al-Diwanyia. The experiment was design as Complete randomized block designing with three replications arranged for split-pilot design, and Lest Significant Deference's( LSD) 0.05 the main treatment contend two groups seeds rate 25 and 50 Kg ha-1 within there four levels of Nano Ca( 0 , 30 , 60 , 90) PPM I took sample of soil before planting to analysis it and to learn physical and chemical properties table 1. Cowpea( Vigna unguiculata L.) were sowing at two rates 25 and 50kg.ha-1(3 cm depth) at 1/4 , after 7 months I took a samples to measure . The results showed all factors and interactions were significant effect and increased all growth traits (plant height, number of leaves per plant and stem diameter , plant content of protein , carbohydrate total Chlorophyll and fats and active substances ,) lead to increased grain yield max values (2.72 Ton.ha-1) at interaction of 25 seeds rate and 90 ppm Ca Nanoparticles level, while min value(1.9 Ton.ha-1) at interaction 50 seed rate and 0 ppm Ca Nanoparticles level.

Field Test and Structural Stability Analysis of Multi-stage Slope Based on Seepage Coupling Theory

This study takes the slope engineering of the Guangdong North Expressway as the background, and studies the impact of rainfall infiltration on the stability of high slopes through on-site monitoring, data analysis, and model construction. Firstly, based on BC theory, the mechanical calculation model of landslide rainfall is established, and the mechanical formula of slope mechanical properties and Factor of safety considering rainfall process and rainfall infiltration process is derived. Then, by constructing a Fluid–structure interaction numerical calculation model considering the seepage characteristics and mechanical state evolution of the slope, the movement of pore water in the slope under different rainfall intensities and the evolution of the mechanical state and displacement characteristics of the slope were studied. Research has found that the mechanical and numerical calculation models in this article are highly consistent with the actual site conditions, and there may be two potential sliding surfaces in the K738+995 section. The potential sliding surface of K738+910 section is located at a depth of 7 m below the first level platform and 3 m below the third level platform; There may be two potential sliding surfaces in K738+658 section, one is located at the interface between silty clay and sandy clay (9 m below the top of cutting), and the other is mainly located at the interface between sandy clay and completely weathered andesite porphyrite; The surface layer of the slope is silty clay and sandy clay, and the underlying layer is fully strongly weathered andesite porphyrite and moderately weathered dacite. Completely strongly weathered andesite porphyrite is soft, easy to soften and disintegrate when encountering water, and joint fissures are developed. The surface of some cracks is contaminated with iron and manganese, resulting in uneven weathering. The rock is relatively soft and the rock mass is broken. Due to the recent continuous heavy rainfall, the water content of the surface soil of the slope gradually increases and tends to saturation, increasing the self-weight of the slope soil.

Modeling the Compression Behavior of Dredged Sandy Clays Considering the Effect of Initial Water Contents and Sand Fractions

Dredged sandy clays are widely utilized as fill material in geotechnical projects, and their compressibility is crucial to the engineering design. It is well recognized that the compression behavior of dredged sandy clays is significantly affected by the initial water content and sand fraction. Besides, these two physical properties are usually spatially dependent due to the process of hydraulic filling. In this study, an effective compression model is formulated based on the equivalent void ratio concept. The compression curve of pure clays is first established as a reference, which depends on the initial void ratio and liquid limit. Then, the effect of sand fraction has been incorporated by directly implementing the equivalent void ratio into the reference curve. A structural variable is introduced to describe the evolving intergranular structure with coarse content and stress level. Only one additional structural parameter is required, and it can be readily calibrated by one traditional compression test. Validation shows that the model is effective in reproducing the compression behavior of dredged sandy clays with a wide range of initial water content and sand fraction. The proposed equation can provide a reasonable reference for establishing the hardening law and the corresponding general constitutive model of dredged sandy clays.

Groundwater Investigation through Electrical Resistivity Tomography in the Galhareri District, Galgaduud Region, Somalia: Insights into Hydrogeological Properties

Electrical resistivity tomography (ERT) was conducted to delineate groundwater potential zones in villages located in the Galhareri district of the Galgaduud region, central Somalia. A total of four ERT profiles were examined using the gradient configuration, chosen for its practical advantages over other configurations. The study revealed that all profiles were situated within similar geological environments, characterized by comparable rock types. However, notable disparities were observed in lithological variations, particularly in the texture of rocks encountered at different locations and in the thicknesses of the encountered geo-electric layers. The two-dimensional inversion results derived from the electrical resistivity data unveiled the presence of four geo-electrical layers. The first layer was interpreted as sand dunes. The second layer exhibited relatively higher resistivity values, indicating the presence of compact limestone and sandstone. The resistivity of the third layer suggested the existence of a lower resistivity layer, interpreted as weathered limestone, while the fourth layer demonstrated very low inverted resistivity, interpreted as sandy clay with sandstone. The ERT models constructed for the survey area effectively delineated the aquifer zone, represented by layer 3, which likely consists of weathered limestone, sandy clay, and sandstone. The resistivity values obtained for the aquifer zone, specifically at depths ranging from 200 to 300 m, were relatively low, suggesting that the groundwater quality is brackish in nature.

Machine learning-based draft prediction for mouldboard ploughing in sandy clay loam soil

Machine learning (ML) models are developed to predict draft for mouldboard ploughs operating in sandy-clay-loam soil. The draft of tillage tools is influenced by soil cone-index, tillage-depth, and operating-speed. We used a three-point hitch dynamometer to measure draft force, a cone penetrometer for soil cone-index, rotary potentiometers for tillage-depth, and proximity sensors for operating-speed. Draft requirements were experimentally measured for a two-bottom mouldboard plough at three different tillage-depths and various operating-speeds. We developed prediction models using recent ML algorithms, including Linear-Regression, Ridge-Regression, Support-Vector-Machines, Decision-Trees, k-Nearest-Neighbours, Random-Forests, Adaptive-Boosting, Gradient-Boosting-Regression, Light-Gradient-Boosting-Machine, and Categorical-Boosting. These models were trained and tested using a dataset of field measurements including soil cone-index, tillage-depth, operating-speed, and corresponding draft values. We compared the measured draft with the commonly used ASABE model, which resulted in an R2 of 0.62. Our ML models outperformed the ASABE model with significantly better performance. The test data set achieved R2 values ranging from 0.906 to 0.983. These results demonstrate that the developed ML models effectively capture the complex nonlinear relationship between input parameters and draft of mouldboard plough.

CNN deep learning performance in estimating nitrate uptake by maize and root zone losses under surface drip irrigation

Optimal fertigation regimes will minimize the leaching of agrochemicals while providing crops with sufficient nutrition for growth. A comprehensive objective function of optimization involves minimizing (i) difference between weekly plant nitrogen uptake and requirement and (ii) nitrate losses (nitrate leaching and accumulated nitrate in the root zone). Coupling a simulation model to an optimization algorithm for obtaining the objective function variables (N plant uptake and nitrate losses) typically requires long runtimes as the simulation model is repeatedly applied over iterations of the optimization algorithm. One attractive way to reduce the programming and computational demands associated with optimization is to construct a simpler, faster, but sufficiently accurate emulator of the simulation model based on machine-learning model. This study assessed the performance of convolutional neural networks (CNN) in modelling nitrate uptake by maize and estimation of nitrate losses in surface drip irrigation in three texturally different soils. To do this, the CNN was trained on output of the simulation model HYDRUS-2D. Various combinations of parameters influencing daily nitrate uptake (daily potential crop evapotranspiration, irrigation water and injected fertilizer amount) were evaluated as model inputs. Results indicated that daily nitrate uptake at any time t was predicted best with inputs of daily potential evapotranspiration at time t, irrigation and fertilizer amounts of the previous 1–7 days and the previous day’s nitrate uptake amount. Estimated nitrate losses for constant weekly fertigation (CWF) were about 32% in sandy loam and 38.5% in sandy clay loam soil. Variable weekly fertigation (VWF) reduced the nitrate losses to 24.5% in sandy loam and 31.5% in sandy clay loam soil, while losses in loam soil were intermediate to these. The study demonstrates that CNN estimation of nitrate uptake and root zone losses can be widely used in optimization of fertigation management.

Tomato varieties superiority assessment under organic and inorganic (granular and foliar) fertilization in sandy clay soil

Tomato is valued for its nutritional importance and contribution to countries' GDP. Despite the importance of tomatoes, tomato cultivation remains a challenge in some cities, particularly Kumba, Cameroon. This results from a vast knowledge gap for a suitable variety and agronomic management practices. Thus this work was set out to investigate the response of three tomato varieties under organic, foliar, and granular inorganic fertilization at the Kumba I subdivision. This work comprised two factors; variety having three levels (Cobra F1, Rio Grande, and Kiara tomato varieties) and fertilization having four levels (control, NPK 20:10:10 granular fertilizer, Foliar NPK 20:10:10 inorganic fertilizer, and Poultry manure) given twelve treatment combinations replicated three times randomly in a factorial design. Data was collected on soil physicochemical properties, plant growth parameters and fruit yield. The results showed that the variety did not significantly affect soil physicochemical properties, but soil physicochemical properties were significantly affected by fertilization. Poultry manure had the best OC (5.22 %), Ntot (1.73 g/kg), and Pavail (14.63 mg/kg), while K was highest (2.93 meq/100g) in NPK 20:10:10 granular fertilization. Rio grande, in combination with poultry manure, had the best plant growth; plant height (77.3 cm), number of branches (17), number of leaves (197), and leaf area (47.1 cm2). Cobra F1, in combination with foliar NPK 20:10:10 granular and poultry manure, had the best fruit yield; 13.42 tha-1 and 13.56 tha-1, respectively while Kiara variety at the control treatment had the lowest yield (8.36 tha-1). Thus Cobra F1 variety in combination with poultry manure yielded the best result from this study and offers the best option for tomato cultivation in the sandy clay soils of Kumba, Cameroon.

English

Phytoavailable cadmium (Cd) refers to the fraction of total cadmium in soil that is easily taken up by plants, which degrades the environmental quality and can cause contamination in the food chain. Cd contamination causes high carcinogenicity and toxicities, which harm both the environment and human health, including damage to the kidneys, bones, and respiratory system. In this study, seven extracting agents like ammonium bicarbonate diethylene triamine penta acetic acid (ABDTPA) and neutral salts having low and higher concentrations were used for the determination of phytoavailable Cd in sandy clay loam (SCL) and clay loam (CL) soils contaminated with Cd at naturally-Cd, Cd-20, Cd-40, and Cd-60 mg kg-1 and correlate it with Cd contents in roots, shoots, and grains of maize crop. Extraction efficiency of extractants remains in order: 10 M NH4AOc > ABDTPA > 1 M NH4AOc > 0.1 M CaCl2 > 0.01 M CaCl2 > 1 M NaNO3 > 0.1 M NaNO3. ABDTPA showed significantly the highest positive correlation with maize roots, shoots, and grains Cd contents in naturally Cd contaminated SCL and CL soils. While for artificially contaminated SCL and CL soils contaminated with Cd at Cd-20, Cd-40, and Cd-60 contamination levels, 0.1 M CaCl2 extractable Cd showed a stronger positive significant correlation with Cd contents in roots, shoots, and grains of maize crop. Overall results concluded that 10 M NH4AOc has the highest efficiency to extract Cd and 0.1 M NaNO3 has the lowest Cd extraction efficiency. Correlation results showed that ABDTPA and 0.1 M CaCl2 were found to be the most suitable extractants for predicting the bioavailability of Cd. Highly concentrated extractants give a stronger positive correlation as compared to low concentrated extractants. SCL soil showed stronger positive correlations as compared to CL soil

A modified approach to model the hydrological effects of living moss and fallen leaves on carbonate-derived laterite in karst forests

Due to recent vegetation restoration projects in karst mountainous areas of China, the living moss and litter layer play important roles in controlling soil water dynamics in karst forests. However, the underlying mechanisms of the effects of moss and the litter layer on soil water dynamics are still controversial. To explore the underlying mechanisms, we employ the CoreKarHydro model, capturing soil water content dynamics driven by evapotranspiration and influenced by living moss and fallen leaves. This model integrates surface changes' impact on evapotranspiration, categorizing the domain into: no cover (S), moss (SM), pine needles (SP), and both (SMP). Model validation employs the MOCOM-UA method, using diverse metrics (RMSE, R2, ACC, ED, KGE and SA) against lysimeter data with 4 moss biomass levels and 3 pine needle biomass levels. The results indicated: 1) The CoreKarHydro model exhibited reliable performance in simulating the soil water content curves, with an RMSE ranging from 1.49% to 4.21% and an R2 value ranging from 0.60 to 0.77. 2) Among the factors that influenced evaporation processes, soil hydraulic properties emerged as the most sensitive parameters, whereas the properties of the moss and pine needles played a relatively lesser role. 3) The impact of moss cover on evaporation processes varied depending on the soil texture and the stage of evaporation. Moss cover reduced evaporation loss in 8 out of 12 soil textures (loamy sand, loam, silt, silt loam, sandy clay loam, silty clay loam, sandy clay, and silty clay). On the other hand, moss cover increased evaporation loss in 4 out of 12 soil textures (sand, sandy loam, clay loam, and clay). This study contributes to the understanding of the mechanisms of coupled soil-moss(litter)-hydrological processes in karst areas.