Soil Components Research Articles

Dissemination of antibiotic resistance genes is regulated by iron oxides: Insight into the influence on bacterial transformation

The transportation of antibiotic resistance genes (ARGs) in manure-soil-plant continuums poses risks to human health. Horizontal gene transfer, particularly for bacterial transformation, is an important way for ARG dissemination. As crucial components in soils, iron oxides impacted the fates of various abiotic and biotic contaminants due to their active properties. However, whether they can influence the transformation of ARGs is unknown, which waits to be figured out to boost the assessment and control of ARG spread risks. In this study, we have investigated the effects of goethite, hematite, and magnetite (0–250 mg/L, with sizes < 100 nm and > 100 nm) on the transfer of ampicillin resistance genes to Escherichia coli cells. At lower iron oxide concentrations, the transformation of ARGs was first facilitated (transformation frequency reached up to 3.38-fold higher), but the facilitating effects gradually weakened and eventually disappeared as concentrations further increased. Particle size and iron oxide type were not the universal determinants controlling the transformation. At lower concentrations, iron oxides interacted with proteins and phospholipids in E. coli envelope structures, and induced the overgeneration of intracellular reactive oxygen species. Consequently, they led to pore formation and permeability enhancement on the cell membrane, thus promoting the transformation. The facilitation was also associated with the carrier-like effect of iron oxides for antibiotic resistance plasmids. At higher concentrations, the weakened facilitations were attributed to the aggregation of iron oxides. In this study, we highlight the crucial roles of the concentrations (contents) of iron oxides on the dissemination of ARGs in soils; this study may serve as a reference for ARG pollution control in future agricultural production.

Investigation of the Dynamic Performance of High-Speed Railway Bridges in Cold Regions Based on Vehicle–Bridge Coupling Vibrations

Abstract This work uses numerical simulations to systematically study the dynamic performance of high-speed railroad bridges in cold areas based on coupled vibration analyses of axles and vehicles during freeze–thaw cycles. The freezing and thawing cycles of perennial frozen soil were established with comsol software, and the changes of the soil components during freezing and thawing cycles were analyzed with an indirect solution method and reasonable hydrothermal parameters and freezing and thawing boundary conditions. With the establishment of a pile–soil interaction simulation model, the change rule for pile foundation displacement and the force characteristics of pile foundations during freeze–thaw cycles were studied. abaqus and um software were used to simulate the coupled vibrations of axles, select the indexes for evaluation of train safety and the smoothness of the high-speed railroad trains, and investigate the influence of foundation freezing and pulling displacements on the dynamic performance of high-speed trains.

Transport behavior of microplastics in soil‒water environments and its dependence on soil components

Microplastic (MP) pollution has become a global concern, and the transport behavior of MPs in soil-water systems is vital in determining their distribution and potential risks to the subsurface environment. To reveal the role of various soil components on MP migration, the downward transport behavior of polystyrene (PS) MPs were explored in this study via column experiments with mono or multi-soil components as porous media. Compared with the selected soil mineral volcanic rock (VR) and fine river sand (RS), condensed soil organic matter (SOM) resulted in higher transport efficiencies for PS microparticles, with greater than 90% total mass recovery under the experimental conditions. The more surface charges of SOM than minerals contribute to the high migration efficiency of PS MPs, and electrostatic repulsion is assumed a significant driving mechanism in the migration of negatively charged PS particles in soils. The ionic strength of porewater influenced the PS migration behaviors by altering the electrostatic interactions between the MPs and soil grains. The uniform mixing of SOM with mineral grains significantly enhanced the transport efficiency of PS MPs in the columns. The results provide supports for the prediction and prevention of the risks of MPs to the subsurface environment.

Multiple Functions of Microbes to Improve Food and Soil Nutrition in Support of Environment Management to Maintain Global Agricultural Practices

Plant-microbe interactions are interesting phenomena Soil microbial biomass is considered the living part of the soil organic matter, which acts as an agent of transformation of organic matter and is a source of available nutrients. Activities of soil microbes can change the soil environment rapidly and influence the rate of nutrient cycling. Soil microbes also play a significant role in the formation of macro aggregates. The potential of soil microorganisms has been recognized widely for the improvement of soil quality, soil formation, aggregation, and revegetation. Soil microbes are involved in various ecosystem processes, such as litter decomposition, phosphate solubilization, nitrogen fixation, oxidation of various inorganic components of soil or mineralization of inorganic components, and mycorrhizal symbiosis. Implications of plants and their symbionts like mycorrhizal fungi, nitrogen-fixing bacteria, and free-living rhizosphere populations of bacteria promote plant establishment and growth. Therefore, active soil microbial biomass is an essential component for long-term soil fertility. The application of microbial technology which we can refer to as green technology has become an integral element of forestry as well as agriculture and has substantially contributed to forest and agricultural productivity and ensuring the ecosystem’s sustainability. This article reviews some of the important aspects of microbial applications in agriculture and forestry and discusses different facets of microbial functions, their interaction with plants and soil, and their role in the sustainability of natural resources, forests, and agroecosystems.

Assessment of Activity Concentrations and Soil-to-Plant Transfer Factors of Natural Radioactivity in Rice Plant Components grown in Kano State, Nigeria

Transfer Factor (TF) depicts the percentage or fraction of natural radioactivity in the soil that is absorbed by different parts of a plant which are eventually transferred, directly or indirectly, to man during ingestion. Activity concentrations of primordial radionuclides were determined in farm soil and rice plant components (root, stem, leaf and seed) in six Local Government Areas (Bagwai, Bunkure, Dambatta, Garko, Kura and Wudil) renowned for production of rice in Kano State, Nigeria, using gamma-ray spectrometry method with sodium iodide scintillation detector. The mean activity concentrations of 40K, 238U and 232Th were: 509.51, 27.75, and 12.26 Bq.kg-1 correspondently in soil; 227.40, 14.24, and 5.19 Bq.kg-1 correspondingly in seed; 935.53, 32.73, and 7.29 Bq.kg-1 accordingly in leaf; 803.65, 16.72, and 6.76 Bq.kg-1 respectively in stem; and, 408.91, 30.03, and 10.31 Bq.kg-1 correspondingly in root. The mean concentrations of 40K reported in soil were greater than the world average of 400 Bq.kg-1, while those of 238U and 232Th were less than the world mean values of 35 Bq.kg-1 and 30 Bq.kg-1 respectively. The estimated mean of TFs of 40K, 238U and 232Th were: 0.52, 0.61, and 0.43 respectively in the seed; 1.95, 1.45, and 0.69 respectively in leaf; 1.72, 0.75, and 0.64 correspondingly in the stem; and, 0.85, 1.27, and 0.76 accordingly in the root. Except for a few plant samples where BDL were recorded for 238U and 232Th, all values of TFs were greater than the recommended values of 4.9 x 10-3 and 2.1 x10-4 given for 238U and 232Th...

Assessment of adjacent building vibrations induced by metro with a multigrid fully coupled method

The vibrations generated by metro operations can cause structural damage and discomfort to occupants adjacent to the metro lines. In this study, a multigrid fully coupled method of metro vehicle-track-station-soil-building systems is proposed to predict and assess building vibrations before construction. This approach facilitates the efficient calculation of the fully coupled system, while ensuring precise simulations through the utilization of multigrid techniques for wheel-rail contact, track, station, soil, and building components. Using the newly built opera theatre along Beijing metro line 4 as a case, the study demonstrates that the multigrid fully coupled model can predict the dynamics characteristics of metro-induced vibrations and distribution with high accuracy compared with the field tests. Specifically, it was found that metro operations could result in vibrations exceeding specified limits in the opera theatre, particularly at 10∼40 Hz (the building’s natural frequency) and 60∼80 Hz (the main frequency band of vibration caused by the metro). Finally, the mechanism of excessive vibration and the effectiveness of targeted vibration mitigation measures were analyzed with the proposed method. These findings have promising implications for wider applications in environmental assessments and control strategies for new metro lines or vibration-sensitive buildings.

Spatiotemporal variation of water balance components in Mashhad catchment, Iran: Investigating the impact of changes in climatic data and land use

Abstract The research aims to investigate the spatiotemporal changes of water balance components and distinguish the relative impacts of climatic data and land-use on groundwater level in northeastern Iran. This investigation employs the WetSpass-M model to estimate water balance and the Mann-Kendall test alongside Sen's slope estimator to evaluate trend. The study also assesses mean annual water balance components, considering diverse combinations of land-use and soil. The findings offer a hydrological insight, revealing that 14% of precipitation results in runoff, 29% of that recharging the aquifer; the remaining portion is lost through evapotranspiration. The trends in precipitation and simulated water components are not significant but a significant downward trend in groundwater is observed beyond a specific point in time. Based on this outcome, as well as the analysis of land-use changes, it was speculated that human activities in this fast-developing region might be implicated in the decline in groundwater levels. Analysis of water balance components in various soil and land-use combinations indicates that evapotranspiration exhibits greater variability within the land-cover class, while recharge is more influenced by soil texture. These findings enhance our understanding for identifying potential sites for artificial recharge and determining sustainable groundwater withdrawals based on spatiotemporal recharge patterns.

Methodology for Regional Soil Organic Matter Prediction with Spectroscopy: Optimal Sample Grouping, Input Variables, and Prediction Model

Soil organic matter (SOM) is an essential component of soil and is crucial for increasing agricultural production and soil fertility. The combination of hyperspectral remote sensing and deep learning can be used to predict the SOM content efficiently, rapidly, and cost-effectively on various scales. However, determining the optimal groups, inputs, and models for reducing the spatial heterogeneity of soil nutrients in large regions and to improve the accuracy of SOM prediction remains a challenge. Hyperspectral reflectance data from 1477 surface soil samples in Northeast China were utilized to evaluate three grouping methods (no groups (NG), traditional grouping (TG), and spectral grouping (SG)) and four inputs (raw reflectance (RR), continuum removal (CR), fractional-order differentiation (FOD), and spectral characteristic parameters (SCPs)). The SOM prediction accuracies of random forest (RF), convolutional neural network (CNN), and long short-term memory (LSTM) models were assessed. The results were as follows: (1) The highest accuracy was achieved using SG, SCPs, and the LSTM model, with a coefficient of determination (R2) of 0.82 and a root mean squared error (RMSE) of 0.69%. (2) The LSTM model exhibited the highest accuracy in SOM prediction (R2 = 0.82, RMSE = 0.89%), followed by the CNN model (R2 = 0.72, RMSE = 0.85%) and the RF model (R2 = 0.69, RMSE = 0.91%). (3) The SG provided higher SOM prediction accuracy than TG and NG. (4) The SCP-based prediction results were significantly better than those of the other inputs. The R2 of the SCP-based model was 0.27 higher and the RMSE was 0.40% lower than that of the RR-based model with NG. In addition, the LSTM model had higher prediction errors at low (0–2%) and high (8–10%) SOM contents, whereas the error was minimal at intermediate SOM contents (2–8%). The study results provide guidance for selecting grouping methods and approaches to improve the prediction accuracy of the SOM content and reduce the spatial heterogeneity of the SOM content in large regions.

Insights into the pH-dependent interactions of sulfadiazine antibiotic with soil particle models

Sulfonamide antibiotics (SAs) are widely used as a broad-spectrum antibiotic, leading to global concerns due to their potential soil accumulation and subsequent effects on ecosystems. SAs often exhibit remarkable environmental persistence, necessitating further investigation to uncover the ultimate destiny of these molecules. In this work, molecular dynamics simulations combined with complementary quantum chemistry calculations were employed to investigate the influence of pH on the behavior of sulfadiazine (SDZ, a typical SAs) in soil particle models (silica, one of the main components of soil). Meanwhile, the quantification of SDZ molecules aggregation potential onto silica was further extended. SDZ molecules tend to form a monolayer on the soil surface under acidic conditions while forming aggregated adsorption on the surface under neutral conditions. Due to the hydrophilicity of the silica, multiple hydration layers would form on its surface, hindering the further adsorption of SDZ molecules on its surface. The calculated soil-water partition coefficient (Psoil/water) of SDZ+ and SDZ were 9.01 and 7.02, respectively. The adsorption evaluation and mechanisms are useful in controlling the migration and transformation of SAs in the soil environment. These findings provide valuable insights into the interactions between SDZ and soil components, shedding light on its fate and transport in the environment.

Evaluation of Total Concentrations and Extractable Fractionations of Cd, Co and Ni in Soils from Dumpsites across Rivers State, Nigeria

The mobility of trace metals in soils strongly depends on the forms in which the metals are bound to major soil components. This study aims to determine the total concentrations and extractable fractionations of Cd, Co and Ni in soil samples collected from dumpsites across Rivers State, Nigeria. Solar Thermo Elemental Atomic Absorption Spectrometer model (SG 71906) was used after mixed acid digestion (HCl: HNO3 in a ratio of 3:1 v/v) and modified BCR sequential extraction procedure. The concentration levels of Cd, Co and Ni in all the samples varied, with mean values of 13.48 11.85, 25.29 17.62 and 20.52 15.66 mg/kg, respectively. Using the Community Bureau of Reference (BCR) sequential extraction procedure, the elements recoveries were within the acceptable range varying between 92.10% and 98.33% for Co and Cd, respectively. Data from the BCR extraction procedure revealed that the majority of Cd fraction was associated with residual fraction, Co fraction bound to the exchangeable fraction, while Ni was found to be associated with oxidisable fraction. These results suggest that the trace elements in the soil were highly mobile and bioavailable for plant uptake. Results from the findings particularly correlation analysis is indicative of the fact that some of the contaminants may have anthropogenic and natural origin. Hence, these contaminants could pose significant threat to human health and the environment.

Functional organic matter components in mangrove soils revealed by density fractionation

ABSTRACT The mechanisms underlying stabilization of soil organic matter (SOM) in vegetated coastal ecosystems, including mangrove forests, are poorly understood, limiting our ability to predict the consequences of disturbances. Here, we introduce density fractionation to mangrove soils to identify the distribution and properties of the functional components of SOM regarding degradation state, stability, and origin, namely, the free low-density fraction (f-LF), mineral-associated LF (m-LF), and high-density fraction (HF). Three soil cores (1 m) were collected in a mangrove forest on Ishigaki Island, Japan, and cut into 10 cm intervals and analyzed. Although HF was the most abundant, the massive production of mangrove fine roots resulted in a high abundance of LFs throughout the cores, which markedly differed from terrestrial soils. Relative abundance of LFs together accounted for 38–66% of total soil C. The m-LF was as abundant as f-LF and 1.6 times higher in relative abundance than the global average of terrestrial soils. The C/N ratios and δ13C values clearly increased with depth in all fractions, which was attributed to the increased contribution from roots. We found a consistent pattern in Δ14C values of density fractions. HF was the oldest with Δ14C between −149‰ and −97‰ followed by m-LF (between −130‰ and −87‰) and then f-LF (between −89‰ and 78‰), suggesting that mineral association may be pivotal in long-term carbon storage in the mangrove mineral soil. Our analysis successfully identified meaningful functional components of mangrove SOM, yet several questions remained unanswered, including a large variability in Δ14C in different cores. Future studies would benefit from a coupled analysis of the quantity and quality of density fractions and geochemical factors in mangrove soils.

Proof of Principle of the Lunar Soil Volatile Measuring Instrument on Chang’ e-7: In Situ N Isotopic Analysis of Lunar Soil

The nitrogen isotopic compositions of lunar soil have important implications for the sources of lunar volatiles and even the evolution of the moon. At present, the research on the lunar nitrogen isotopic compositions is mainly based on the lunar meteorites and the samples brought back by the Apollo and Luna missions. However, volatiles adsorbed on the surface of the lunar soil may be lost due to changes in temperature and pressure, as well as vibration and shock effects when the sample is returned. At the same time, in the case of low N content in the sample, since N is the main component of the earth’s atmosphere, it is easily affected by the atmosphere during the analysis process. Therefore, in situ nitrogen isotopic analysis of lunar soil on orbit is necessary to avoid the problems mentioned above and is one of the primary science goals for the Lunar Soil Volatile Measuring instrument on Chang’e-7 spacecraft. After the nitrogen purification procedure, the volatiles in lunar soil that are released through single-step or stepped heating techniques diffuse to the quadrupole mass spectrometer to obtain the N contents and isotopic compositions of the lunar soil. This paper introduces the ground test for N isotopic analysis of lunar soil in orbit according to the Lunar Soil Volatile Measuring Instrument. After long-term repeated measurements, the background and CO-corrected Air-STD 14N/15N ratio is 268.986 ± 4.310 (1SD, n = 35), and the overall reproducibility of measurements is 1.6%. The accuracy of N isotopic compositions is calculated to be better than 5%, which can distinguish different sources of N components in lunar soil.

Parameter Calibration for Discrete Element Simulation of the Interaction between Loose Soil and Thrown Components after Ginseng Land Tillage

Given the lack of accurate and reliable discrete element simulation parameters to study the interactions between soft soil and soil casting components after ginseng land cultivation in Northeast China and the design of ginseng land-specific borders, this paper calibrates the relevant model parameters of ginseng soil using the Hertz–Mindlin with JKR contact model in EDEM to standardize the contact parameters between soil particles and between soil and Q235 steel in soft soil after cultivation in ginseng land. Taking the soil particle accumulation angle as the response value, a Box–Behnken design (BBD) was introduced to establish a regression model for the soil accumulation angle; the surface energy, static friction coefficient, rolling friction coefficient, and coefficient of restoration parameters were obtained, respectively, through the optimization of the model, at which time, the simulated value of the soil accumulation angle was 37°, which is a 4% relative error to the actual measured accumulation angle of 35.5°. Taking the sliding friction angle of the soil on the Q235 steel plate as the response value, the regression model of the soil sliding friction angle was obtained based on the BBD. The static friction factor, rolling friction factor, and coefficient of restitution between the soil particles and the Q235 steel were obtained, respectively. Based on the combination of these parameters, the simulated value of the sliding friction angle was 32.2°, which is a 2% relative error to the measured accumulation angle of 31.5°. To verify the accuracy of the optimized simulation parameters, field and simulation tests of soil-throwing components were conducted. The results show that the maximum relative error between the measured value and the simulation value is 5.6% and 3.4%. The error is within an acceptable range, and the simulation test and field test soil-throwing effects are the same, which verifies the accuracy and reliability of the reference soil parameter calibration. The results of the study can be used for discrete element simulation analysis of the interaction between ginseng loam and touchdown components and their structural optimization.

The soil-microbe-plant resistome: A focus on the source-pathway-receptor continuum.

The One World, One Health concept implies that antibiotic resistance (AR) in the soil-microbe-plant resistome is intricately linked to the human resistome. However, the literature is mainly confined to sources and types of AR in soils or microbes, but comprehensive reviews tracking AR in the soil-microbe-plant resistome are limited. The present review applies the source-pathway-receptor concept to understand the sources, behaviour, and health hazards of the soil-microbe-plant resistome. The results showed that the soil-microbe-plant system harbours various antibiotic-resistance genes (ARGs), antibiotic-resistant bacteria (ARB), and mobile genetic elements (MGEs). Anthropogenic sources and drivers include soil application of solid waste, wastewater, biosolids, and industrial waste. Water-, wind-, and human-driven processes and horizontal gene transfer circulate AR in the soil-microbe-plant resistome. The AR in bulk soil, soil components that include soil microorganisms, soil meso- and macro-organisms, and possible mechanisms of AR transfer to soil components and ultimately to plants are discussed. The health risks of the soil-microbe-plant resistome are less studied, but potential impacts include (1) the transfer of AR to previously susceptible organisms and other resistomes, including the human resistome. Overall, the study tracks the behaviour and health risks of AR in the soil-plant system. Future research should focus on (1) ecological risks of AR at different levels of biological organization, (2) partitioning of AR among various phases of the soil-plant system, (3) physico-chemical parameters controlling the fate of AR, and (4) increasing research from low-income regions particularly Africa as most of the available literature is from developed countries.

Response of soil water, salt, carbon and bacteria community to terrain and plant in coastal salt marsh

Terrain and plants play a crucial role in influencing or regulating the variations of water, salt, carbon, and bacteria community in the soil of coastal salt marshes. Investigating these variations and their interconnections under different conditions is essential to comprehensively understand the carbon sequestration function and reveal the underlying mechanisms of carbon sinks in coastal salt marshes. In this study, the various physicochemical properties of rhizosphere and non-rhizosphere soil under different terrain of coastal salt marsh in Jiaozhou Bay were determined. Additionally, the contents of soil carbon components including soil inorganic carbon (SIC), soil organic carbon (SOC), dissolved inorganic carbon (DIC), and dissolved organic carbon (DOC), and constituents of soil dissolved organic matter (DOM) and microbial community were analyzed. The results showed that the contents of SIC and SOC in high-terrain soil were significantly lower than those in low-terrain soil (P < 0.05). Plants could regulate the physicochemical properties, and carbon components of soil in different terrain, resulting in no significant difference in SOC contents of rhizosphere soil under different terrain. Soil DOM composition and bacterial community showed that high-terrain soil had higher bacterial diversity and activity, and plants significantly affected the bacterial community structure in soil through rhizosphere effects. The structural equation model demonstrated that terrain has an indirect impact on SOC through influencing on the fluorescence of soil DOM and bacterial diversity, and SIC through altering soil water content (SWC), electrical conductivity and DOC. Plants directly or indirectly affected SOC content, and indirectly affected SIC content by changing SWC. This study contributes to a better understanding of the complex interactions between wetland ecosystems and their soil water, salt, carbon, and bacteria community components, offering valuable information for wetland management and conservation efforts.

Response of Soil Microorganisms and Phenolic to Pseudostelariae heterophylla Cultivation in Different Soil Types

Pseudostellaria heterophylla of the Caryophyllaceae family is an important medicinal herb in traditional Chinese medicine, but it encounters continuous cropping obstacle during cultivation. This study aimed to study the differences in the response of Pseudostellaria heterophylla cultivation to soil microorganisms and phenolic substances in different types of soil (Loamy soil and Clayey soil). The analysis of soil metabolites using HPLC-ESI-Q/TOF-MS and HPLC-DAD techniques revealed that the content of various phenolic components in the rhizosphere soil increased significantly after Pseudostellaria heterophylla cultivation. Pseudostellaria heterophylla cultivation in yellow soil could increase the abundance of Proteobacteria, Ascomycota, and Thermoplasmatota, while in brown soil, the abundance of Ascomycota significantly decreased. In addition, Pseudostellaria heterophylla cultivation could increase the α-diversity of bacteria and fungi in yellow soil, while reducing the α-diversity of archaea, and the impact on diversity in brown soil was relatively small. Correlation analysis showed that phenolic compounds were more likely to regulate the genera Bradyrhizobium, Calcarisporiella, Boothiomyces and Methanocella. Pseudostellaria heterophylla may regulate rhizosphere microbial diversity and community structure by secreting phenolic. However, in different types of soil environments, the response mechanism of soil microorganisms to Pseudostellaria heterophylla planting might vary. Our study provides new insights that the variability in the response of different soil types to Pseudostelariae heterophylla cultivation should be taken into account when developing strategies for reducing continuous cropping obstacles in medicinal plants.

Mobility and transport of pharmaceuticals nalidixic acid and niflumic acid in saturated soil columns

Pharmaceutical compounds often coexist in mixtures rather than as individual entities. However, little is known about their co-adsorption and co-mobility in soil and groundwater. In this study, we investigated the adsorption of a quinolone antibiotic (nalidixic acid, NA) and an anti-inflammatory agent (niflumic acid, NFA) onto two soils from France and Sweden in water-saturated soil columns. Despite its lower hydrophobicity, adsorption of NA is much greater than NFA, which can be ascribed to the presence of both carbonyl and carboxylic groups in NA molecule. The data suggest that chemical adsorption to soil components can mainly take place through hydrogen bonding and surface complexation mechanisms, prevailing over hydrophobic interactions. Accordingly, more sorption of NA and NFA was observed in the Swedish soil because it contains more clay content, and much greater Al and Fe contents than the French soil. Injection of NA/NFA mixture in the column did not modify the breakthrough behavior compared to single systems, although cooperative adsorption was observed under static batch conditions. Ca2+ inhibited NA adsorption by forming a soluble NA-Ca2+ complex but promoted NFA adsorption both in single and binary systems. Their mobility in soil columns was well predicted using a new transport model that accounts for both kinetics and binding reactions of NA and NFA to soil constituents. This work will help in accurately predicting the mobility of coexisting pharmaceutical compounds in soils.

The Vicious Circle of Climate Challenges With Soil in 5 Continents Caused by Low Cognitive in the Process of Agricultural Revolutions in the World

In the past and present world, whatever we have done on earth, we have not got good results. Such results, which are the result of the efforts of climatologists and soil scientists, have revealed such a deviation from their true line that it requires a change in the operational structure of the minds of all experts in the world for the future sustainability of the earth. The most important achievement of operational (historical) errors, which has had the greatest impact on climate change, the reduction of terrestrial and subterranean biodiversity after the agricultural revolutions, is agricultural soils. In this multipurpose research path, one of the main findings showed that the soil is a source of physicochemical diversity (with creative, biophysical and biochemical value) with the climate, and without soil, the life of all creatures in the world is impossible. This strategic research which was managed with the (SMM) model in the agricultural soils of 5 continents of the world is considered an emerging phenomenon in world history and has been able to attribute about 58.5% of climate changes to the soil during the past 50 years. At the end of this research, for the effectiveness and sustainability of the climate and soil components, 10 universal suggestions have been presented, and this practical idea can be considered as a model of climate change mitigation accepted by technical experts in today's high-risk world.

Effect of particles size on adsorption isotherm of chlorantraniliprole, dinotefuran, bispyribac-sodium, and metribuzin into sandy loam soil

The efficiency of different sorbents (bulk soil, sand, silt, clay and humic acid-HA) for chlorantraniliprole (CAP), dinotefuran (DNF), bispyribac-sodium (BPS), and metribuzin (MBZ) adsorption was described and compared. The adsorption of CAP, DNF, BPS and MBZ were significantly greater on clay and HA fractions than the bulk soils. Also, the tested pesticides sorption was greater on HA fraction compared to clay fraction except in the case of BPS. The mass unit of bulk soil adsorbed of CAP, DNF, BPS and MBZ approximately 15, 20, 10 and 5 % of the same of HA and 40, 60, 95 and 35 % of that of clay fraction, respectively. The actual amounts adsorbed on bulk soil ranged from (88.63 to 93.93 %) of the calculated amounts adsorbed on all soil components indicating high efficiency of the tested soils to adsorb tested pesticides. All adsorption data fitted well to the linear Freundlich equation. The adsorption of tested pesticides in soil and their different constituents is S-type according to 1/n (except some cases).

Carbonate weakens the interactions between potassium and calcareous soil.

The ion interfacial transport driven by ion-surface interactions in calcareous soil has a profound impact on the nutrient storage and environmental buffer capacity of the main agricultural soils in dry and semi-arid areas. The roles that carbonate plays in preserving the soil's inorganic carbon pool and soil structure stability have been widely investigated, but its significance in the aforementioned microscopic processes, especially the influence of carbonate on the interfacial reaction kinetics of nutrient elements, is yet to be determined. In this study, potassium (K) was used as an indicator ion to investigate its affinity in carbonate-removed (CREM) and carbonate-reserved (CRES) calcareous soil using the general theory of ion diffusion in an external electric field. We discovered that (1) at a given initial K concentration, the carbonate in CRES soil retards the adsorption rate and diminishes the adsorption amount of K in calcareous soil, reducing the interfacial transport properties of nutrient ions at the solid-liquid interface of calcareous soils compared with CREM soil; and (2) this weakening of the interfacial transport effect on nutrient K originates from the soil carbonate, which prefers to weaken the electrostatic interaction intensity between K and the calcareous soil surface. Furthermore, this is due to the carbonate shielding effect on the surface adsorption sites of other soil components and the competitive relationship between K+ and cations released by carbonate dissolution. The influence of carbonate on the nutrient ion transport at the solid-liquid interface of calcareous soil has been investigated by soil electrochemistry theory-based ion adsorption kinetics, and the links between kinetic features and ion-surface binding energy have been clarified.