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The paper explores the feasibility of substituting steel working bodies with polymer ones in soil-cultivating units. (Research purpose) The research aims to investigate how the friction parameters of acrylonitrile butadiene styrene (ABS plastic) are affected by variations in absolute soil moisture and speed of the unit during the interaction of its working body with loamy soil. (Materials and methods) A laboratory unit was developed to examine the friction characteristics of the polymer in contact with loamy soil. The study measures the friction and adhesion properties by altering the absolute moisture of loamy soil. (Results and discussion) Graphs were constructed to illustrate the relationship between of the friction parameters of acrylonitrile butadiene styrene (ABS plastic) on absolute soil moisture. It was determined that at absolute soil moistures of 18, 20 and 26 percent, the friction coefficients of acrylonitrile butadiene styrene are 0.45, 0.5 and 0.6, respectively. The adhesion values were recorded at 100, 145 and 700 pascals for absolute soil moistures of 18, 20 and 28 percent, respectively. A decrease in both friction and adhesion was observed when the soil moisture reached between 26% and 28%. (Conclusions) The friction properties of acrylonitrile butadiene styrene (ABS plastic) are lower than those of steel, yet significantly higher than those of fluoroplastic. Further research in this area is expected to significantly increase the effi ciency of selecting materials for the manufacturing of working parts in soil-cultivating units, while also reducing energy costs.

The COVID-19 outbreak has significantly raised the amount of single-use mask waste in Indonesia. This research intends to assess the effect of single-use mask waste on the quality of loamy soil. The investigation involved constructing a prototype using a 28-cm high column of 19 cm of loamy soil. The study utilized single-use masks in the soil, in which Chili plants were grown on the soil surface. Clean water was employed for the leaching process over 45 days. Soil samples from control, R1, R2, and R3 reactors were analyzed in the laboratory using X-ray Fluorescence (XRF) testing and microplastic identification in groundwater. The research findings reveal a notable decline in macro and micronutrients, namely a 1.22% decrease in silicon minerals caused by microplastics interfering with plant metabolic processes. The increase in microplastics caused higher microorganism mortality, leading to a 10.18% decrease in organic carbon content and a 1.47% reduction in soil porosity. Microplastics were discovered in the loamy soil of an average size of 0.3±1.34 mm. Changes in nutrient concentrations and physical properties of the soil indicate that introducing microplastics into loamy soil through mask waste can alter soil characteristics. Additional research is required to investigate the disposal of single-use mask waste due to the ongoing high utilization of disposable masks as personal safety equipment.

Unsymmetrical dimethylhydrazine (UDMH) based rocket fuel, when released into the soil, undergoes oxidative transformations to form a variety of toxic nitrogen‐containing products (TPs). Loamy soils containing aluminosilicates (clay) are capable of strong binding and retention of UDMH TPs due to a combination of polar sorption and cation‐exchange properties, posing challenges for their extraction and quantification. To overcome this problem, the present study proposes direct thermal desorption (TD) of analytes from loam facilitated by the addition of modifiers competing with UDMH TPs for sorption centers and ensuring their conversion into molecular form. Among tested additives, the mixture of potassium chloride and hydroxide demonstrated the best performance and provided recoveries of the most UDMH TPs exceeding 70% under optimized TD conditions (200°C, 30 min). The online combination of TD with gas chromatography‐tandem mass spectrometry allowed for the development of a method for the determination of 15 UDMH TPs in loamy soils with limits of detection in the range of 0.2–15 µg/kg. The use of matrix‐matched calibration and deuterated internal standards ensured high accuracy (80%–100%) and precision (relative standard deviation < 18%) of the analysis. The developed method was validated and successfully tested in the analyses of real loamy soil samples polluted with rocket fuel. [ABSTRACT FROM AUTHOR]

Relevance. To improve the quality of life and expand the taste preferences of the population of Belarus, it is necessary to expand the range of vegetable crops with high yields, marketability and product quality, adapted to the natural and climatic conditions of the republic. In this regard, improving technological methods for cultivating such a crop as zucchini (Cucurbita pepo L.) is of scientific and practical importance. Materials and Methods. The research was carried out on the territory of a private farm in the village of Chukhny, Smorgon district. Field and laboratory studies were carried out using generally accepted methods and guidelines. Results. Substantiated the feasibility of cultivating green manure crops in combination with the local application of thermoammonia-disinfected compost when growing zucchini in seedlings on sod-podzolic light loamy soils in the natural climatic conditions of Belarus. The developed technological methods ensure the reproduction of soil fertility, increased yield, and production of high quality products without the use of mineral fertilizers. When using green manure and disinfected compost, the nitrate content in zucchini cv. Bonus, grown without mineral fertilizers, was in the range of 280-320 mg/kg. To reproduce the fertility of soddy-podzolic light loamy soils when growing zucchini in the natural climatic conditions of Belarus, it is advisable to use oats, oilseed radish and peas as green manure fertilizers. This technological technique increases the content of organic matter in the soil by 0.8-1.3 %. Together with green manure, adding thermo-ammonia-disinfected compost into a hole when planting zucchini seedlings ensures an increase in organic matter content by 1.2-1.5 % in the compost localization zone. During the decomposition of organic matter of green manure crops and disinfected compost applied locally, nutrients are released in quantities sufficient to form a high yield of zucchini with a nitrate content below the maximum permissible concentration. Thus, when grown on soddy-podzolic light loamy soils in the natural climatic conditions of Belarus, the proposed technological methods make it possible to obtain high-quality products and significantly increase the yield of zucchini due to green manure in combination with the local application of disinfected compost without the use of mineral fertilizers.

Purpose: scientific substantiation of the use of agro-reclamation tillage practices of light chestnut heavy loamy soils in rice cultivation with periodic irrigation by sprinkling. Materials and methods. The research was conducted at the experimental site of the All-Russian Research Institute of Irrigated Agriculture in 2022–2023 with Stalingrad 1 rice crops in a two-factor experiment: factor A (soil water regime) – two options and factor B (tillage) – three options. Generally accepted methods of laying and conducting field research were used. Results. Immediately after rice sowing, the soil density in the layer of 0.0–0.6 m, varied in the range of 1.19–1.41 t/cubic m depending on the tillage practice. The minimum value of soil density in the layer of 0.0–0.6 m was formed in the A2B3 variant and amounted to 1.23 t/cubic m. The maximum soil compaction in this layer of 1.34 t/cubic m was observed in variant A1B1. During the period of full ripeness of the grain, soil compaction occurred in all tillage options. Its minimum compaction (1.34 t/cubic m), compared with the control (winter plowing), was noted with a combination of winter plowing and spring deep loosening. The minimum values of the water consumption coefficient and irrigation water loss were obtained in the A2B3 variant, and their numerical values were 851.7 and 703.6 cubic m/t, respectively. Conclusions. It was found that winter plowing to a depth of 0.25–0.27 m in combination with spring deep loosening to a depth of 0.40 m, in comparison with traditional winter plowing in one step, provides a decrease in soil density in a layer of 0.0–0.4 m by 0.10 (after sowing) and 0.12 t/cubic m (during the period of full ripeness of grain), which contributes to the yield increase to 6.95 t/ha and a reduction in irrigation water loss by 112.4 cubic m for the formation of 1 ton of grain.

In the present study, persistence and degradation of tembotrione, a triketone herbicide, was studied in loamy soil collected from maize field. Effects of organic amendments, moistures and temperatures on tembotrione dissipation were evaluated. Soil samples were processed according to the modified QuEChERS involving dichloromethane solvent and MgSO4 without PSA. Analysis using LC-MS/MS showed >95% recoveries of tembotrione its two metabolites TCMBA and M5 from fortified soils. Tembotrione residues dissipated with time and 85.55 to 98.53% dissipation was found on 90th day under different treatments. Tembotrione dissipation increased with temperature and moisture content of the soil. Among organic amendments, highest dissipation was observed in vermicompost amended soil. Minimum and maximum half-lives of tembotrione were recorded under 35 °C (15.7 days) and air-dry (33 days) conditions, respectively. Residues of tembotrione declined with time while that of TCMBA increased steadily up to 10-45th day in different treatments and declined thereafter. Residues of M5 were not detected in our experiments. Tembotrione persistence was negatively correlated with the organic carbon (%), moisture regimes, and temperature. A good correlation between soil microbial biomass carbon and degradation was found. A two-way ANOVA indicated significant differences between the treatments at 95% confidence level (p < 0.05). [ABSTRACT FROM AUTHOR]

Introduction Soil contamination due to heavy metals is a global environmental issue. One vital aspect for understanding the impact of a contaminant in porous media is to describe their transport behavior using appropriate models. The governing equations for solute transport in soil consist of the convection–dispersion equation (CDE) and the mobile–immobile model (MIM). Mathematical models are usually used to evaluate solute transport in porous media. The first model used to express the transport of solutes and pollutants in porous media is CDE it provides acceptable and satisfactory results in homogeneous soils in laboratory tests. Hydrus-1D is a modeling environment for simulating water, heat, and solute movement in one-dimensional variably saturated media. Sensitivity analyses and model identification are standard approaches in modeling applications to investigate the relative importance of model components that control the system’s behavior. The sensitivity analysis is applied to identify the parameters that influence the model performance most. The sensitivity analysis is defined as the rate of variation in the model outputs due to changes in the input parameters. This study is a fundamental practice for analyzing the behavior of a model under different conditions of an application. The sensitivity analysis could be a practical and powerful tool for investigating the role and importance of model components, such as parameters and forcing data on the model responses. Materials and Methods The loamy soil samples were collected in both disturbed and undisturbed forms from a farm in the Qaramalek area with appropriate humidity located in western Tabriz, Iran, at 38º 5' 59.89' north and 45º 12' 38.57' east. To determine and present breakthrough curves, concentration values are required throughout the laboratory columns at different times. To simulate the CDE model, Hydrus software was used. Solute transport parameters such as diffusion coefficient (D), distribution coefficient (Kd), and dispersion coefficient (β) were estimated using soil hydraulic parameters and data related to the metal concentration of cadmium, nickel, and zinc by an inverse modeling method. A sensitivity analysis was carried out for the identification of the most influential factors on the model output. This method examines the impact of input data on a given model and its actual conditions. In line with this purpose, in each run, one input data was changed to a value equal to Positive and negative five to 15%, and the other input data was kept constant. To identify the effect of the input parameters of a given model on its output, the sensitivity analysis for the Hydrus model was utilized. The parameters of hydrodynamic dispersion coefficient (D), distribution coefficient (Kd), and spreading parameter (β) were changed between five to 15 %. Sensitivity analysis was carried out on cadmium, nickel, and zinc metals with densities equal to 50, 100, and 150 mg l-1 in two disturbed and undisturbed soils. Results and Discussion Examining the breakthrough curves of cadmium in disturbed and undisturbed soils shows that the fitted curves using the Hydrus model and the measured curve almost coincide with each other, which is more obvious in disturbed soils. It should be noted that the model fits better in the disturbed soil than in the undisturbed soil. This may be due to the disruption of the structure the increase in the contact surface of the particles in the disturbed soil and the presence of heterogeneity in the undisturbed soil column. The simulation results show the transport of heavy metals (Zn, Ni, Cd) and Hydrus output have the highest and the lowest sensitivity to dispersion coefficient β and diffusion coefficient (D), respectively. In general, the impact of input parameters can be reported as follows: spreading parameter (β) > distribution coefficient (Kd) > dispersion coefficient (D). Therefore, it can be observed that D has a negligible effect on the model results; and consequently, measurement errors can be ignored. Conclusion Sensitivity analysis is used to analyze model behavior under different conditions. This analysis is used to investigate the relative importance of model components that control the system’s behavior. In this research, the transfer of hydraulic parameters of heavy metals Cd, Ni, and Zn in disturbed and undisturbed loam soil columns with initial concentrations of 50, 100, and 150 mg l-1 was performed under the simulation of the Hydrus-1D model. The comparison of the simulated BTCs of the Hydrus-1D model and the measured data indicates a high agreement between the simulation curves and the measured data. Solute transport parameters such as hydrodynamic dispersion coefficient (D), distribution coefficient (Kd), and spreading parameter (β) were estimated using soil hydraulic parameters and data related to Cd, Ni, and Zn metal concentration by inverse modeling method. Based on the results of sensitivity analysis, the spreading parameter (β) and hydrodynamic dispersion coefficient (D) had the highest and lowest sensitivity, respectively. In other words, due to the significant effect of β changes on the output values of the model, this parameter should be measured more accurately and on the other hand, the measurement errors of parameter D can be ignored. The degree of sensitivity of the parameters was independent of the initial concentration of the elements. [ABSTRACT FROM AUTHOR]

The study’s main aim was to evaluate the effects of complex mineral fertilizers on the complex properties of heavy loam soils in the grey forests of Russia in terms of applying individual soil nutrition components from experiments with fodder beets. This study employed a rigorous and systematic approach to accomplish the defined goal. Specifically, the research was conducted within a seven-field crop rotation system, with fodder beets serving as the primary experimental crop. In addition, a model experiment resembling a vegetation trial was undertaken, incorporating seven distinct schemes involving various types of fertilizers. This design facilitated the evaluation of the effectiveness of each fertilizer type. The study results demonstrate that complex fertilizers impact the soil’s chemical and biophysical parameters. Soil acidity decreases through the use of complex, high-nitrogen fertilizers. Major chemical nutrients (nitrogen, phosphorus, and potassium) in plant biomass and soil also have a high degree of transition. It is explained by the effects of combining elements on the destruction intensity of the crystalline lattice in the basic structures of potassium, phosphorus, and nitrogen. There is also evidence that complex fertilizers can improve humus quality and replenish its reserves. All the aforementioned impacts of complex fertilizers on the crop contribute to the high productivity and yield of forage beet. The results of the study may help optimize the fertilization process, improve the quality and quantity of agricultural products, as well as increase soil fertility, and reduce the negative impact of agrochemicals on the environment.

The COVID-19 outbreak has significantly raised the amount of single-use mask waste in Indonesia. This research intends to assess the effect of single-use mask waste on the quality of loamy soil. The investigation involved constructing a prototype using a 28-cm high column of 19 cm of loamy soil. The study utilized single-use masks in the soil, in which Chili plants were grown on the soil surface. Clean water was employed for the leaching process over 45 days. Soil samples from control, R1, R2, and R3 reactors were analyzed in the laboratory using X-ray fluorescence (XRF) testing and microplastic identification in groundwater. The research findings reveal a notable decline in macro and micronutrients, namely a 1.22% decrease in silicon minerals caused by microplastics interfering with plant metabolic processes. The increase in microplastics caused higher microorganism mortality, leading to a 10.18% decrease in organic carbon content and a 1.47% reduction in soil porosity. Microplastics were discovered in the loamy soil of an average size of 0.3 ± 1.34 mm. Changes in nutrient concentrations and physical properties of the soil indicate that introducing microplastics into loamy soil through mask waste can alter soil characteristics. Additional research is required to investigate the disposal of single-use mask waste due to the ongoing high utilization of disposable masks as personal safety equipment. [ABSTRACT FROM AUTHOR]

The study's main aim was to evaluate the effects of complex mineral fertilizers on the complex properties of heavy loam soils in the grey forests of Russia in terms of applying individual soil nutrition components from experiments with fodder beets. This study employed a rigorous and systematic approach to accomplish the defined goal. Specifically, the research was conducted within a seven-field crop rotation system, with fodder beets serving as the primary experimental crop. In addition, a model experiment resembling a vegetation trial was undertaken, incorporating seven distinct schemes involving various types of fertilizers. This design facilitated the evaluation of the effectiveness of each fertilizer type. The study results demonstrate that complex fertilizers impact the soil's chemical and biophysical parameters. Soil acidity decreases through the use of complex, high-nitrogen fertilizers. Major chemical nutrients (nitrogen, phosphorus, and potassium) in plant biomass and soil also have a high degree of transition. It is explained by the effects of combining elements on the destruction intensity of the crystalline lattice in the basic structures of potassium, phosphorus, and nitrogen. There is also evidence that complex fertilizers can improve humus quality and replenish its reserves. All the aforementioned impacts of complex fertilizers on the crop contribute to the high productivity and yield of forage beet. The results of the study may help optimize the fertilization process, improve the quality and quantity of agricultural products, as well as increase soil fertility, and reduce the negative impact of agrochemicals on the environment., Competing Interests: The authors declare that there are no conflicts of interest regarding the publication of this paper., (Copyright © 2024 Sergey Gaidar et al.)

The article presents data on how bentonite clay (applied at reclamation rates) affects acid-alkaline characteristics and fertility indicators of soil (sod-podsolic sandy loamy soil - retisols). The experiment was conducted in the Nizhny Novgorod region. Physical and chemical properties of the used bentonite clay were preliminary studied. It is characterized by alkaline reaction of aqueous solution (pH 10.9) and of salt extract as well (pH 9.8) and undergoes electrolytic dissociation. The micro-plot field experiment which lasted over 3 years revealed some positive effect of bentonite application. As a result, the lowering of exchangeable soil acidity (by 0.31. pHKci units) and hydrolytic soil acidity (by 0.20 mg-eqv./100 g) was recorded, substantial reduction of aluminium soluble forms content (up to 48 %) was noticed as well, meanwhile the content of exchangeable Ca2+ and Mg2+ increased by 0.70 and 0.24 mg-eqv./100 g correspondingly. Bentonite application contributed to humus preservation in the soil and humus content was maintained at 1.221.28 % level. Moreover, this practice helped to increase the content of soluble (available) phosphorus and potassium compounds (on average by 27-30 % depending on experiment trial). The studied bentonite clay was proved to have stabilizing effect on acid-alkaline and nutrition balances in the soil. Some interaction between mineral soil part and bentonite clay is supposed to take place which results in the reconstruction of chemically-active fine particles (so-called active mineral centers) in soil adsorption complex.

Biochar (BC) is used as a soil amendment to enhance plant growth by improving mainly soil chemical and hydrophysical properties. In this work the effects of two types of BCs on soil water retention properties were analysed. The first type of BC was made from sugarcane bagasse. It was added to a clay "Shimajiri Maji" soil at an application rate of 3 w%. The second type of BC was made from paper fiber sludge and grain husks. It was added into a loam soil at rates of 3.6, and 7.3 w%. It was assumed that the effect of BC amendment will be more pronounced in coarse-grained soil than in fine-grained one. Therefore, the second type of BC was applied additionally in the silica sand, in a textured contrast material compared with the loam soil. The BC amendment caused statistically significant increase of water content in the transmission pores of the clay soil, in the storage pores of the loam soil, and in the macropores and the storage pores in the silica sand. Despite of the positive effect on soil water retention, statistically significant increase of available water capacity (AWC) was identified only in the loam soil with the larger BC amendment rate. Possible reasons are discussed.

In bare soils of semi-arid areas, surface crusting is a rather common phenomenon due to the impact of raindrops. Water infiltration measurements under ponding conditions are becoming largely applied techniques for an approximate characterization of crusted soils. In this study, the impact of crusting on soil hydraulic conductivity was assessed in a Mediterranean vineyard (western Sicily, Italy) under conventional tillage. The BEST (Beerkan Estimation of Soil Transfer parameters) algorithm was applied to the infiltration data to obtain the hydraulic conductivity of crusted and uncrusted soils. Soil hydraulic conductivity was found to vary during the year and also spatially (i.e., rows vs. inter-rows) due to crusting, tillage and vegetation cover. A 55 mm rainfall event resulted in a decrease of the saturated soil hydraulic conductivity, Ks, by a factor of 1.6 in the inter-row areas, due to the formation of a crusted layer at the surface. The same rainfall event did not determine a Ks reduction in the row areas (i.e., Ks decreased by a non-significant factor of 1.05) because the vegetation cover intercepted the raindrops and therefore prevented alteration of the soil surface. The developed ring insertion methodology on crusted soil, implying pre-moistening through the periphery of the sampled surface, together with the very small insertion depth of the ring (0.01 m), prevented visible fractures. Consequently, Beerkan tests carried out along and between the vine-rows and data analysis by the BEST algorithm allowed to assess crusting-dependent reductions in hydraulic conductivity with extemporaneous measurements alone. The reliability of the tested technique was also confirmed by the results of the numerical simulation of the infiltration process in a crusted soil. Testing the Beerkan infiltration run in other crusted soils and establishing comparisons with other experimental methodologies appear advisable to increase confidence on the reliability of the method that seems suitable for simple characterization of crusted soils.

Intra-field heterogeneity of soil properties, such as soil organic carbon (SOC), nitrogen (N), phosphorous (P), exchangeable cations, pH, or soil texture, is a function of complex interactions between biological factors, physical factors, and historic agricultural management. Mapping the crop growth and final yield heterogeneity and quantifying their link with soil properties can contribute to an optimization of amendment/fertilizer application and crop yield in a management variable zones (MVZ) approach. To this end, we studied a field of 17 ha consisting of four former fields that were merged in early 2017 and cropped with winter wheat in 2018. Historical management practices data were collected. The topsoil characteristics were analyzed by grid-based sampling and kriged to create maps. We tested the capacity of a multispectral MicaSense® RedEdge-MTM camera sensor embedded on an unmanned aerial vehicle (UAV) to map in-season growth of winter wheat. Relating several vegetation indices (VIs) to the plant area index (PAI) measured in the field highlighted the red-edge NDVI (RENDVI) as the most suitable to follow the crop growth throughout the growing season. The georeferenced final grain yield of the winter wheat was measured by a combine harvester. The spatial patterns in RENDVI at three phenological stages were mapped and analyzed together with the yield map. For each of these images a conditional inference forest (CI-forest) algorithm was used to identify the soil properties significantly influencing these spatial patterns. Historical management practices of the four former fields have induced significant heterogeneity in soil properties and crop growth. The spatial patterns of RENDVI are rather constant over time and their Spearman rank correlation with yield is similar along the growing season (r ≃ 0.7). Soil properties explain between 87% (mid-March) to 78% (mid-May) of the variance in RENDVI throughout the growing season, as well as 66% of the variance in yield. The pH and exchangeable K are the most significant factors explaining from 15 to 26% of the variance in crop growth. The methodology proposed in this paper to quantify the importance of soil parameters based on the CI-forest algorithm can contribute to a better management of amendment/fertilizer inputs by stressing the most important parameters to take into consideration for site-specific management. We also showed that heterogeneity induced by the soil properties can be described by a crop map early in the season and that this crop map can be used to optimize soil sampling and thus amendment/fertilizer management.

Abstract Background The growing production and use of engineered AgNP in industry and private households make increasing concentrations of AgNP in the environment unavoidable. Although we already know the harmful effects of AgNP on pivotal bacterial driven soil functions, information about the impact of silver nanoparticles (AgNP) on the soil bacterial community structure is rare. Hence, the aim of this study was to reveal the long-term effects of AgNP on major soil bacterial phyla in a loamy soil. The study was conducted as a laboratory incubation experiment over a period of 1 year using a loamy soil and AgNP concentrations ranging from 0.01 to 1 mg AgNP/kg soil. Effects were quantified using the taxon-specific 16S rRNA qPCR. Results The short-term exposure of AgNP at environmentally relevant concentration of 0.01 mg AgNP/kg caused significant positive effects on Acidobacteria (44.0%), Actinobacteria (21.1%) and Bacteroidetes (14.6%), whereas beta-Proteobacteria population was minimized by 14.2% relative to the control (p ≤ 0.05). After 1 year of exposure to 0.01 mg AgNP/kg diminished Acidobacteria (p = 0.007), Bacteroidetes (p = 0.005) and beta-Proteobacteria (p = 0.000) by 14.5, 10.1 and 13.9%, respectively. Actino- and alpha-Proteobacteria were statistically unaffected by AgNP treatments after 1-year exposure. Furthermore, a statistically significant regression and correlation analysis between silver toxicity and exposure time confirmed loamy soils as a sink for silver nanoparticles and their concomitant silver ions. Conclusions Even very low concentrations of AgNP may cause disadvantages for the autotrophic ammonia oxidation (nitrification), the organic carbon transformation and the chitin degradation in soils by exerting harmful effects on the liable bacterial phyla.

The aim of the research was to investigate the soil properties and the species diversity of diatoms growing in different agricultural fields with silt loamy soil. The field experiment was conducted in 2014 in Kosina, near Łańcut (SE Poland), at three sites (indicated as fields K1, K2, K3) with different soil environmental conditions and plants. The growth of winter wheat Triticum aestivum (cv. Bogatka) in fields K1 and K2 and oats Avena Sativa (cv. Haker) in field K3 under different soil management were studied. The soil samples were collected from the top layers (0-5 cm depth) each month, from April to December. Certain physical and chemical parameters of soil were measured. The pH of soil was acidic and slightly acidic in fields K1 (5.0-5.4), K2 (4.9-5.9) and K3 (4.5-5.1). The soil in field K3 had a significantly greater content of organic matter (1.06-1.30%) and water content (12.9–33.8%, v/v) than fields K1 and K2. A total of 91 diatom taxa were found. The diversity was greatest in field K2 (71 taxa), lower in K1 (54 taxa) and K3 (24 taxa). In K1, the most numerous species were Luticola D.G. Mann cf. mutica, Mayamaea atomus var. permitis (Hust.) Lange-Bertalot, and Stauroneis thermicola (Petersen) Lund, with more than a 20% share in the assemblage. In K2, very abundant assemblages were formed by Mayamaea atomus (Kütz.) Lange-Bertalot, Mayamaea atomus var. permitis (Hust.) Lange-Bertalot, and Stauroneis thermicola (Petersen) Lund with a 25 to 50% share in the total diatom community. In K3, with oat cultivation, a different diatom species structure was found. Here, the most abundant were Halamphora montana (Krasske) Levkov, Hantzchia amphioxys (Ehrenb.) Grunow, Mayamaea atomus (Kütz.) Lange-Bertalot, and Nitzschia pusilla Grunow, which attained a share in the assemblage exceeding than 20%. The effects of different soil management regimes under different plants on the physical and chemical properties of the soil, and on the diversity of diatoms, were significant (P

The activity concentrations of natural radionuclides 226Ra, 232Th and 40K in soil samples collected from Sijua Dhanbad, India were measured by using a gamma-ray spectrometer with a NaI(Tl) detector. The average activity concentration of 226Ra, 232Th, and 40K was found as 60.3, 64.5 and 481.0 Bq. kg−1, respectively. Average radium equivalent activity, absorbed dose rate, outdoor dose, external hazard index and internal hazard index for the area under study is determined as 189.5 Bq. kg−1, 87.2 nGy h−1, 0.4, 0.5 and 0.6 mSv. y−1, respectively. The annual effective dose to the general public is found 0.4 mSv. y−1. This value lies well below the limit of 1 mSv. y−1. Measured values have found safe for the environment and public health of the study area.

Effects of incorporating urea with wheat or corn straw at different soil moisture levels on ammonia volatilization were measured in a field experiment using a sponge-tripping method with KCl extraction. Over a 10-day period following incubation NH3 volatilization peaked on day 3 for urea alone, while highest emission rates were observed on day 2 for urea plus wheat or corn straw. Total NH3 losses decreased in the order: urea > urea + maize straw > urea + wheat straw. Emissions of NH3 were more sensitive to soil moisture after straw addition and correlation analysis showed that NH3 volatilization was also significantly affected by pH of the surface soil. To reduce ammonia losses at the farm level application of urea fertilizer should consider the straw type and soil properties.

Due to their broad applications, ionic surfactants have already been released into or utilized in soil and environmental systems. However, current understanding on the sorption behavior of surfactants onto soils is still limited. This work systematically investigated the sorption kinetics and isotherms of one cationic surfactant, cetyltrimethylammonium bromide (CTAB), and one anionic surfactant, sodium dodecyl sulfate (SDS), onto a silt loamy soil to determine the governing sorption mechanisms. The pseudo-second-order rate equation described the sorption kinetics data better than the pseudo-first-order rate equation. Experimental data showed that the sorption equilibrium for CTAB and SDS were reached at 24 and 240 h, respectively. Langmuir equation was better than Freundlich equation in simulating the sorption isotherms of CTAB and SDS on the soil. Soil Langmuir maximum sorption capacity of CTAB was much higher than that to SDS. When the experimental temperature increased, the sorption of CTAB and SDS on the soil decreased. In addition, the sorptive process of the surfactants on the soil was spontaneous and exothermal, as indicated by the absolute values of Gibbs free energy and enthalpy. The results also indicated that physical sorption was the dominant mechanism for the sorption of the two surfactants on the soil. Findings from this work are crucial to understand the environmental behaviors of ionic surfactants.

The agronomic use of natural zeolite is widely supported by several works. However, almost all are focused on the application of the clinoptilolite as slow plant-nutrient fertilizer and soil conditioner. Our study describes the first comprehensive study on the effects of a Italian chabazite-bearing zeolitite (rocks containing more than 50% of zeolites) on a maize cultivation. The objective was to determine the effects of applying zeolitite on (i) Zea mays yield and quality, under two irrigation regimes and (ii) check if it can improve the efficiency of urea fertilization on a loamy soil in an open experimental field of Italy. The production and quality of the corn grown in the traditional way was compared with that of the plots treated with two different amounts of zeolitite (4 and 8 Kg/m2) and each treatment was monitored both in irrigated and not-irrigated conditions. The measurements of chlorophyll and those related to the morphological features of the plants show suffering conditions of the corn plants in not-irrigated conditions. Furthermore we show that the plants grown with zeolitite and fertilized with less urea have produced the same amounts of corn plants fertilized with traditional contents of urea.

In arid and semi-arid regions, soil salinity is a common problem threatening fertility of irrigated lands. The Lower Euphrates valley in Syria suffers from salt accumulation in soil because of the inappropriate climatic conditions, using the traditional methods in irrigation; flood irrigation. HYDRUS 1-D model was used to simulate water flow, salt transport and root water uptake processes in this area. Data from seventy soil profiles were acquired from the pedological reports obtained from the Ministry of Irrigation in Syria. Representative monthly evapotranspiration (ET0) values in Deir Ez-Zor were taken from the FAO CLIMWAT database. The seventy soil profiles were grouped in fourteen zones distributed over the study area. For each zone, the monthly recharge and its salt concentration was estimated. The model was run for 24-month duration. The results showed increasing in soil salinity and, consequently, increasing in salts load transmitted into groundwater. Accordingly, mitigation measures have been suggested.

The mobilization and transport of colloid particles in soils can have negative agronomic and environmental effects. This work investigates the controls of particle release and transport from undisturbed soil columns sampled from an agricultural, loamy field with clay and silt contents of 0.05 to 0.14 and 0.07 to 0.16 kg kg-1, respectively. Forty-five soil columns (20 x 20 cm) were collected from the field and exposed to a constant irrigation of 10 mm h-1 for 8 h. The accumulated mass of particles in the outflow from each column was highly correlated (r = 0.88) with the volumetric mass of fines (MFvol). The MFvol is defined as the sum of clay and fine silt (<20 mm) multiplied by the soil bulk density and divided by the particle density of the mineral fines. Thereby, MFvol represents both the particle source available for mobilization and leaching and an indicator of soil structure. The particle release process showed two linear particle release rates. Although the two particle release rates were distinctly different, both were strongly correlated with MFvol. The difference between the two rates was related to the degree of preferential flow characterized by the 5% arrival time of an applied tracer pulse. Soil columns with a longer 5% arrival time (less preferential flow) showed a distinct difference between the two rates, whereas soil columns with a short 5% arrival time and fast water transport showed resemblance between the two particle release rates. Thus, the combined effects of particle source, type, and pathways (via soil structure and compaction) need consideration to understand and predict particle transport dynamics through intact topsoil. [ABSTRACT FROM AUTHOR]

The long-term effect of 87.3 kg/ha P on the yield elements and nutrient content of maize was studied at the National Long-Term Fertilization Experiment of the Karcag Research Institute in Hungary. The soil of the experiment site is non-calcareous Luvic Phaeosem, and its soluble phosphorus (P) and zinc (Zn) content in 0-20 cm soil layer are: ammonium lactate P: 141.1 mg/kg and diethylene triamine pentaacetic acid (DTPA)Zn: 0.85 mg/kg, respectively. The effect of foliar Zn fertilization was studied at three levels of nitrogen (150, 200 and 250 kg/ha) and under 87.3 kg/ha P and 82.6 kg/ha K application in four replications. The applied Zn amount was 700 g/ha. We measured the grain yield and the thousand-kernel weight. Leaf and grain samples were analyzed for phosphorus, zinc, potassium, calcium, magnesium and manganese content. Foliar Zn application did not increase the yield significantly, but it enhanced the thousand-kernel weight. The element content did not change significantly - neither in leaves nor in kernels. Under the examined habitat circumstances even the long-term application of 87.3 kg/ha P dosage did not cause Zn deficiency to such an extent which would lead to significant yield depression of maize.