Original Soil Research Articles

Soil type regulates the divergent loss characteristics of sediment associated carbon and nitrogen in different size classes during rainfall erosion on cultivated lands

Sediment associated carbon and nitrogen loss under rainfall, an important cause of soil quality degradation and water eutrophication, strongly depends on the intrinsic properties of original soil types. Relative to total loss, the transport behaviors of organic carbon and nitrogen among sediment size classes and response to soil types remain poorly understood. The concentrations of organic carbon (OC) and total nitrogen (TN) in different sediment size classes (>1, 0.25–1, 0.10–0.25, and <0.10 mm) and their contributions to total sediment load during rainfall erosion were determined under field plot rainfall simulation (at 90 mm h−1) on three contrasting soil types (Luvisol, Alisol and Ferralsol) with increased aggregate stability. During rainfall erosion, the concentrations of OC and TN in total and different sized sediments decreased first and then reached a steady state. The variability of OC and TN concentrations (coefficient of variations in 4.2–53.1% and 6.6–41.9%) among sediment size classes decreased from Luvisol to Ferralsol. Compared to original soils, sediments exhibited larger C/N ratios for Luvisol, and smaller values for Alisol, indicating the more selective transport of labile organic matter for weaker aggregated soils. Among sediment size classes, fine particles (<0.10 mm) accounted 69–88% of total OC and TN losses for Luvisol, and decreased to 30–39% for Ferralsol; and the main transport mechanisms of sediment associated OC and TN shifting from suspension-saltation (<0.10 mm) to rolling (>0.25 mm) with increased aggregate stability. Among original soil properties, inorganic cementing agents (including amorphous iron oxides and clay minerals) showed closer relationships with sediment OC and TN losses (|r| = 0.61–0.89, p < 0.001) than organic matter properties (|r| = 0.55–0.87, p < 0.001), further implying the important role of soil aggregate stability across soil types. This study provides an in-depth understanding on soil carbon and nitrogen losses and their divergent characteristics among soil types deserves consideration in the development of erosion model and land management in agricultural systems.

The medieval croft plužina field system in a mountain region of central Europe: The interdisciplinary record of the earthen field boundaries in Debrné, Czechia

AbstractThe integration of archaeological, historical and geoarchaeological records represents a significant contribution to research into the medieval landscape. This study focuses on the medieval field system in the deserted village of Debrné, located in northeastern Bohemia, Czechia. The village features a well‐preserved croft plužina field system, a typical historical landscape of central Europe. The main and most visible elements of the field system are the earthen field boundaries, which were the focus of the geoarchaeological investigations. Archaeological excavations in trench S1 revealed a collection of larger stones at a depth of 1 m, potentially serving a drainage function akin to the observed plužina. Additionally, a boulder paving, identified as a remnant of a path between fields, provided insights into the historical use of the area. In trench S2, positioned closer to the village's core, layers with increasing stone content were recorded at a depth of 130 cm. However, the drainage structure observed in trench S1 was not replicated. The dating of earthen field boundaries indicated the creation of the terrace in the second half of the 16th century in trench S1. In trench S2, radiocarbon dating at a depth of 70 to 80 cm ranged from 1025 to 1175 A.D., predating the first written source about Debrné. Optically stimulated luminescence (OSL) dating in trench S2 suggested exposure to sunlight during the third century A.D. Archaeobotanical analysis of charred macroremains from trench S1 revealed 236 plant macroremains belonging to approximately 20 taxa, showcasing wild‐growing, collected useful species such as raspberry, blackberry and elderberry. Trench S2 yielded 23 plant macroremains belonging to 11 taxa, with similar species as trench S1. Pedological and micromorphological examinations displayed distinct layering in both trenches, showing up to six layers. Micromorphological analysis unveiled vuggy microstructures, varying grain sizes and elemental patterns, shedding light on different periods of occupation. Multidisciplinary investigations of the buried soils forming the earthen field boundaries discovered that the original soil cover comprised automorphic lixisols and cambisols, which also form under present conditions. These results underscore the importance of integrating pedological, geoarchaeological, archaeobotanical and physical data to comprehend the intricate nature of anthropogenic landscape changes.

Chemical Characteristics of Shallow Groundwater in the Yellow River Diversion Area of Henan Province and Identification of Main Control Pollution Sources

The northern plain of Henan in the lower reaches of the Yellow River is an area where the Yellow River is frequently diverted. The shallow groundwater quality in this area is poor， and many types of components have been found to be exceeding the limit value； however， the contribution of various environmental factors to water quality needs to be further quantified. In order to clarify the genesis of water quality of shallow groundwater in the study area， 330 groups of shallow groundwater samples were collected via a regional water quality survey. The evolution of shallow groundwater quality in the Yellow River diversion area of northern Henan was revealed using the principal component-absolute principal component score-multiple linear regression （PCA-APCS-MLR） model. The results showed that the components with a shallow groundwater excess rate greater than 10% in descending order were manganese， iron， total hardness， total dissolved solids， sodium， fluoride， arsenic， chloride ions， sulfate， and ammonium. In particular， the excess rate of manganese reached 76%. The four factors of dissolution enrichment， native origin of soil， redox conditions， and agricultural activities were identified as the main reasons for poor groundwater quality， which accounted for 71.24% of the cumulative interpretation rate of variance. In addition， the recharge from the surface water also influenced the groundwater quality. The effects of dissolution between the water and aquifer matrix and redox condition in the aquifer of the Yellow River dried-riverway like Xinxiang were significantly enhanced， resulting in the increasing concentration of iron， arsenic， total hardness， TDS， and other components in groundwater. Fluoride enrichment was caused by dissolution enrichment， the origin of the soil， and lateral replenishment of the Yellow River. Groundwater with high manganese concentration was widely affected by the soil matrix. Nitrate pollution of the groundwater was caused by the extensive use of chemical fertilizers in agricultural activities in individual areas.

Paths of Reforestation of Thinking: Interculturality from Indigenous Philosophies

This text aims to affirm Indigenous philosophies as wisdom that contributes significantly to the way of thinking/feeling education and philosophy. From the Western tradition, philosophy has been constituted from the rupture of what we call mythical thought. Indigenous philosophies, however, start from the mythical narrative, symbolic thought, dreams, orality, and all the ancestry they carry to constitute their cosmologies. To affirm Indigenous thought is, therefore, to recover what was denied, showing that philosophy does not have a single soil of origin (Greece), but is built in different territories and historical times. The negation of indigenous philosophies translates, in many moments, to the very ontological negation of those who have produced and continue to produce thought. Therefore, Indigenous philosophies are forms of reforestation of monocultural rationality and can compose other political-pedagogical exercises, in which good living is a central element. The objective is to show that Indigenous philosophies carry ways of life that contribute to rethinking the “civilizing” processes that have led humanity and the planet to the destruction of the diversity of thought and, with this, teach us to live interculturality as a necessary learning for the survival of knowledge and peoples.

BEHAVIOR OF PHYSICAL AND DENSITY PROPERTIES OF SOFT SOIL STABILIZED WITH NICKEL SLAG

Soft soils have become a significant challenge in geotechnical engineering, due to their low bearing capacity and susceptibility to deformation. Chemical stabilization using nickel slag is an alternative solution and is considered more environmentally friendly. This article focuses on the utilization of nickel slag as a binder material aimed at behavior of physical and mechanical properties of soft soil stabilized with nickel slag soft soil. The nickel slag was carried out with variations of 3%, 6%, 9% and 12% by weight of soil. All the test using ASTM procedure in order to gain physical and mechanical value. The results of this study showed that plasticity index decrease with the increasing of slag nickel concentration, where it is an indication of a change in soil consistency, shifting from initially soft to now medium. Futher, the optimum dry density (d-opt) value of the original soil used was 1.09 gr/cm3, while the optimum dry density (d) values at 3%, 6%, 9% and 12% nickel slag addition were 1.12 gr/cm3; 1.15 gr/cm3; 1.19 gr/cm3 and 1.22 gr/cm3, respectively. These results show that the presence of nickel slag can increase influence the physical and density properties of soft soil, which indicates that nickel slag has the potential to be used as a stabilization material in soft soil.

Analisis Penyelidikan Tanah Box Culvert STA. 4+550 dan STA. 8+575 dengan Sondir Manual Paket I.4 – Pembangunan Jalan Kawasan Industri Terpadu (KIT) Batang

The Government of the Republic of Indonesia is developing the Batang Integrated Industrial Estate (KIT), a national strategic project in the shape of an industrial park. A particularly vital industrial region, the Batang Integrated Industrial Estate (KIT) is situated in the northern economic corridor of Java and has access to the Trans Java Toll Road, the rail network, as well as nearby dry ports and port facilities. In order to connect the roads in the Batang Integrated Industrial Estate (KIT) with district roads and national roads or North Coast roads (Pantura), Package I.4-Road Construction of the Batang Integrated Industrial Estate was constructed. In order to ascertain the pertinent stratigraphic and physical characteristics of the soil on which the construction site was built, a soil investigation was conducted during construction. This process is used to assess whether the soil is stable enough to support the construction of a building. Data will be gathered in the form of soil resistance forces against the sondir or cone layers following an investigation or soil study. The sondir test can also be used to determine the required foundation depth, to precisely determine the original soil's bearing capacity, and to choose the appropriate type foundation to use. Location of Sta. 4+550 has a Box Culvert with sufficient embankment height so that it needs to be replaced as deep as -2.00 meters, while the location of the Box Culvert is at Sta. 8+575 embankment height is higher, it requires analysis of soil bearing capacity and settlement so that the replacement depth and use of mini pile foundation can be determined.

Metabolomics Reveals the Effects of Nitrogen/Phosphorus/Potassium (NPK) Fertilizer Levels on Cucumber Fruit Raised in Different Nutrient Soils.

Fertilizers are widely used to improve the quality of fruits and vegetables. However, the overuse of fertilizers has become an issue because it causes environmental problems and negatively affects productivity and fruit quality. In this study, we examined the effects of nitrogen, phosphorus, and potassium (NPK) fertilizer levels on the metabolism of cucumber fruit in low- and high-nutrient soils using mass-spectrometry-based metabolomics approaches. Cucumber metabolite content was notably different depending on the initial soil nutrient status. Most amino acids and phenylpropanoids were abundant in the cucumbers raised in low-nutrient soil, whereas organic acids, some amino acids (aspartate, glutamate, and ornithine), and carbohydrates were comparatively higher in fruits from high-nutrient soil. The fertilizer supply resulted in an alteration in the metabolite profile, while no change in fruit yield was observed in either low- or high-nutrient soils. Fertilizer treatment perturbed the metabolite contents in cucumbers from low-nutrient soil. In contrast, treatment with higher concentrations of fertilizer in high-nutrient soil increased phenylpropanoid content in the cucumbers, while most metabolites decreased. In conclusion, fertilization levels should be carefully determined, considering culture conditions such as the original soil status, to increase product yield and fruit quality and avoid environmental problems.

Study of Residual Soil Permeability Coefficient Post Addition of Coal Fly Ash

Residual soil is soil that is often used as barrier cover soil at the closure of B3 waste storage facilities. This is because the shear strength of the soil is quite good. The minimum value of the soil permeability coefficient (k) for barrier hoods at the closure of B3 waste storage facilities is 10-7 cm/sec. Many residual soils have a soil permeability coefficient (k) of less than 10-7 cm/sec. Because the dominant compound in coal fly ash is silica, mixing this fly ash with residual soil can reduce the value of the soil permeability coefficient (k) and is also expected to increase the shear strength value of the soil. In this study, residual soil samples were mixed with fly ash at 5%, 10%, 15%, 25% and 35% of the dry weight of the soil. This research aims to determine the effect of adding fly ash on the parameters of dry density, shear strength and soil permeability. The tests carried out were standard proctor testing, direct shear test, and Falling-Head permeability testing. The residual soil used in this research came from Hamlet I, Bintang Meriah Village, Pancur Batu District, Deli Serdang Regency. Based on standard proctor testing, the maximum density (gd max) of original soil is 1,410 gr/cm3. The largest maximum density (gd max) was obtained when adding 15% fly ash, namely 1.471 gr/cm3. In the direct shear test, the original soil cohesion value was 0.024 kg/cm² with an internal shear angle of 37.96º. In the variation of adding 15% fly ash, the cohesion value was 0.131 kg/cm² with an internal friction angle of 53.08º. Based on the Falling-Head permeability test, the original soil permeability coefficient value was 1.98 x 10-6 cm/s. The permeability coefficient value for variations in adding 15% fly ash was obtained at 8.02 x 10-8 cm/s.

Effects of Coal Gasification Slag on the Migration of Cd2+ and Pb2+ in Soil

In recent years, coal gasification slag has been widely used as an adsorbent in many countries worldwide. To better understand remediation of soil heavy metal pollution by coal gasification slag, it is necessary to examine and analyze the influence mechanism of the adsorption characteristics of coal gasification slag on the migration of heavy metal ions in the soil. In this study, we used a soil water movement model and convection-dispersion equation and constructed a model of heavy metal migration after soil improvement by coal gasification slag; then, we evaluated and predicted the influence of heavy metal infiltration with liquid on groundwater after soil improvement. Combined with the soil column experiment, HYDRUS-1D software was used to predict the migration behavior of heavy metals in the soil. The results showed that the dispersion of the sample with coal gasification slag was smaller than that of the original soil sample, and the permeability coefficient of the soil was reduced by 59.34%; after adding coal gasification slag, the adsorption rates of Cd2+ and Pb2+ on the soil samples were higher than 95% and 99% respectively. The constructed heavy metal migration model was fitted well and predicted the migration behavior of heavy metals in the soil satisfactorily. The addition of coal gasification slag can effectively prevent the infiltration of Cd2+ and Pb2+ in the soil and can mitigate groundwater pollution. Therefore, using the adsorption characteristics of coal gasification slag to study the migration behavior of Cd2+ and Pb2+ in soil has important practical significance for soil adsorption and provides a new idea for the comprehensive utilization of coal gasification slag.

Rainfall- and Irrigation-Induced Landslide Mechanisms in Loess Slopes: An Experimental Investigation in Lanzhou, China

To reveal the mechanism of rainfall- and irrigation-induced landslides in loess slopes within cold regions, a series of tests on loess samples subjected to different permeability durations were conducted, and the effects of rainfall on several performance indicators, including the permeability coefficient, composition, microstructure, soil–water characteristic curve, and the shear strength of the loess, were investigated. The results show that the permeability coefficient of the loess decreased by 68% after permeability testing. With increased permeability duration, there is a marked decrease in total dissolved solids, sand particles, and clay particles, contrasted with an increase in silt particles. This dynamic alters the original soil structure and impacts the soil–water characteristic curve of the loess. Additionally, rainwater infiltration heightens the effective saturation of the loess, in turn diminishing the shear strength of the loess as effective saturation increases. This reduction in shear strength is further intensified with extended infiltration time (or rainfall duration). A landslide is triggered once the shear strength diminishes to the level of the geostatic stress of the loess slope, and the influence of the rainfall-induced loss of soil shear strength should be taken into account during slope stability analysis. This study enhances the understanding of the initiation mechanisms of rainfall-induced landslides in loess slopes.

Unraveling the impact of lanthanum on methane consuming microbial communities in rice field soils.

The discovery of the lanthanide requiring enzymes in microbes was a significant scientific discovery that opened a whole new avenue of biotechnological research of this important group of metals. However, the ecological impact of lanthanides on microbial communities utilizing methane (CH4) remains largely unexplored. In this study, a laboratory microcosm model experiment was performed using rice field soils with different pH origins (5.76, 7.2, and 8.36) and different concentrations of La3+ in the form of lanthanum chloride (LaCl3). Results clearly showed that CH4 consumption was inhibited by the addition of La3+ but that the response depended on the soil origin and pH. 16S rRNA gene sequencing revealed the genus Methylobacter, Methylosarcina, and Methylocystis as key players in CH4 consumption under La3+ addition. We suggest that the soil microbiome involved in CH4 consumption can generally tolerate addition of high concentrations of La3+, and adjustments in community composition ensured ecosystem functionality over time. As La3+ concentrations increase, the way that the soil microbiome reacts may not only differ within the same environment but also vary when comparing different environments, underscoring the need for further research into this subject.

Zinc speciation in highly weathered tropical soils affected by large scale vegetable production

Agriculture in highly weathered tropical soils often requires considerable application of lime and fertilizers to ensure satisfactory plant nutrient levels. The consequences of these continue long-term applications is not well understood may induce changes in soil chemical properties, the abundance, and speciation of potentially toxic trace element and as well as of micronutrients in agriculture soils. In this study, we evaluated the adsorption (at pH 5) and speciation of Zn in tropical soils (both agricultural and native vegetation) as a function of fertilization and contact time using chemical fractionation analyses and X-ray absorption spectroscopy. The soils overall had high Zn adsorption capacities (∼ 700 mg kg-1), but the agricultural soil was approximately 30 % higher than of the soil under native vegetation, and the proportion of Zn in the mobile fraction was 35 % in native vegetation and 21 % in agricultural soils. Zn speciation via linear combination analysis showed a strong relationship with soil mineralogical composition and reveled that Zn associated with organic matter decreased while Zn associated with P increased after the conversion of soils from native vegetation to highly fertilized soil. Aluminosilicate soil minerals were identified as major sinks of soil Zn, accounting for 34 % of total Zn retention regardless of soil origin and land use. Association of Zn with phosphate (i.e., hopeite) was observed in the agricultural soil samples, which might be an unexpected Zn-bearing mineral in highly weathered tropical soils and could have impacts on Zn plant nutrition.

Comparative Soil Analysis from Different Crime Prone Areas of Kottayam and Kollam Districts of Kerala for Forensic Characterization

Soil is the loose surface material that covers land on which plants grow. It consists of a mixture of organic remains, clay, and rock particles, which gives it its uniqueness from place to place. Because of the uniqueness of soil, it has a high evidential value in the field of forensic science. In the present study, research has been conducted to check the range of variations in the soil collected from different crime-prone areas of Kottayam and Kollam districts of Kerala by physical, chemical, microscopic, and instrumental examination. In physical examination, soil colour, texture, consistency, and density were measured, and in chemical examination, pH and total soluble sulphate of the soil were measured. In instrumental examination, Heavy metal analysis was done by using Atomic Absorption Spectrometry (AAS), which helps to measure the amount of trace elements present in the soil. The study found that each soil has some significant variations that make it unique. In the field of forensic science, this can be highly helpful in determining the origin of soil by examining its colour, texture, structure, content, etc.

Tracing the Origins of Air Contaminants Near Environmental Protection Areas

This case study aimed to assess the impact of particulate matter (PM) emitted by highway works in an ecosystem belonging to one of the most important Atlantic Rainforest remnants in southeastern Brazil. The study was conducted during federal highway works, comprising a toll station construction and lane widening. To the best of our knowledge, this is the most comprehensive study on air pollution and its impacts on Environmental Protection Areas (EPAs) in Brazil. Total suspended particle (TSP) samples were obtained from 2014 to 2016, totaling 1823 samples. Some TSP samples were chosen for ionic and elemental quantification. Daily concentrations ranged from 8 to 345 µg m−3. The TSP concentrations exceeded Brazilian guidelines (240 µg m−3), mainly during the federal highway works. The main determined elements Fe (50–2100 ng m−3) and Mn (3–30 ng m−3) were associated with soil origin. Trace elements (Cu, Co, Ni, V, and Pb), detected from 2 × 10−7 to 54 ng m−3, and high NO3 − (2.4 − 8.3 µg m−3) and SO4 2− (2.6 − 6.8 µg m−3) concentrations were correlated with vehicular emissions. The findings of this study indicate that Cd and Cu represent environmental risks, as they may compromise biochemical plant processes.

Human health risk assessment of metals in soil samples of a Brazilian city with a historic contamination complex.

Rio Grande is a city located on a narrow industrialized and urbanized Brazilian peninsula, characterized by wetlands. Due to population growth, numerous urban backfilled regions were built to expand the territorial area of the city. Currently, more than 60% of the central area of the city comes from the grounding of wetlands. The material used for the expansion of the territory had a history of contamination from metals from the tannery and textile industries (mainly Hg) and urban solid waste. In addition to past sources, the city has an active industrial complex with fertilizer, petrochemical, and grain industries. This study evaluated the risks to human health caused by metals (Hg, Fe, Ni, Cr, Cu, Pb, and Zn) in original soils and backfills, considering the oral, inhalation, and dermal routes of exposure for children and adults using the tool human health risk assessment (HHRA) proposed methodology by USEPA. A total of 63.81% of the original soil samples and 57.14% of the backfill soil samples showed a non-carcinogenic risk (HInc>1) for at least one evaluated metal. Still, approximately 10% of the samples presented carcinogenic risk when the Cr was considered in the hexavalent form. The dermal (Hg, Ni, and Cr) and oral (Fe, Cu, and Zn) exposure routes had the greatest contribution to the total risk. The non-carcinogenic risk for Hg, Cr(VI), and Pb was heterogeneously distributed between the original soils and backfills and associated with the proximity to some pollution sources. Given the complexity of historical occupation in the municipality and the increasing industrialization, both the original areas and the backfills should be included in the risk management strategy to minimize risks.

Methane flux from transplanted soil monoliths depends on moisture, but not origin

Soils both produce and consume methane (CH4), a potent greenhouse gas that contributes to climate change. In coastal forests, upland soils are shifting from being CH4 sinks to sources as sea levels rise, increasingly flooding soils with little prior inundation history. Ecosystem CH4 budgets are highly uncertain due in part to the difficulty in separating fluxes measured at the soil surface into individual production and consumption processes which are likely to have different responses to future environmental conditions. We measured growing season CH4 fluxes from soil monoliths transplanted four years prior along an inundation and salinity gradient to determine how changes in abiotic conditions control CH4 flux rates. To parse net fluxes measured at the soil surface into their component gross rates, we paired field measurements with a stable isotope pool dilution incubation of surface soils. Throughout the growing season, net soil surface CH4 flux was positively correlated with soil moisture (p < 0.01), with lowland-located soils tending towards CH4 sources (mean 0.349 ± 1.11 mg CH4–C m−2 h−1, error is standard deviation) and upland-located soils tending towards CH4 sinks (−0.003 ± 0.003 mg CH4–C m−2 h−1). Transplanted soils’ fluxes were statistically identical to their native neighbors once microtopography-driven differences in soil moisture were controlled for. The pool dilution experiment revealed that production and consumption rates were similar in upland and lowland surface soils (2.82 ± 3.29 μmol CH4 g−1 dry soil d−1 production, 3.47 ± 2.03 μmol CH4 g−1 dry soil d−1 consumption), indicating the majority of production likely occurs at depth in lowland soils. Both gross and net fluxes from transplanted soils showed no effect of soil origin after four years, suggesting low resistance of CH4 cycling to global change drivers. Our results indicate the strength of the coastal forest CH4 sink is likely to decrease in proportion to sea-level rise.

Selective uneven enrichment of soil organic carbon among different-sized sediments under a rain-induced overland flow: 13C stable isotope evidence

Soil organic carbon (SOC) enrichment varies among sediments of different sizes during rain-induced overland flow erosion. This selective transport of SOC is complex in conjunction with the exposure of labile and stable organic carbon (OC), accompanied by heterogeneous aggregate disintegration under raindrop effects. Utilizing the variations in δ13C values of SOC fractions, we traced this selective transport, linking it to aggregate-wrapped SOC changes during erosion. A modified soil pan facilitated the simultaneous monitoring of splash and sheet erosion via artificially simulated rainfall, with control over the intensity and slope. Aggregate composition, SOC distribution, and δ13C values in the erosion samples were analyzed. The results indicated that distinct sorting existed within the aggregate fragments. Along with SOC variation among different sediment sizes, the proportions of clay and fine silt within sediment aggregates increased as a function of slope and rainfall intensity, whereas particulate OC within aggregates decreased. The SOC enrichment ratios (ERocs) and δ13C values in splash-eroded sediments were positively correlated with those in sheet-eroded sediments. The ERocs in splash-eroded sediments were lower than those in sheet-eroded sediments, but δ13C values were the opposite. Moreover, δ13C values of SOC enriched in sediment particles of all sizes from aggregate stripping were lower than those of the original soil. This indicates that raindrop hits promote heavy C loss during sheet erosion, which is different for mineral-associated and particulate OC. As the slope and rainfall intensity increased, δ13C values for all sediment sizes decreased over the course of erosion. Interestingly, the highest δ13C values were observed under a rainfall intensity of 60 mm h−1, whereas the highest SOC concentrations were noted on a 5° slope. These observations suggest divergent mechanisms affect δ13C values and SOC concentrations in eroded sediments. All these results verified that selective sorting existed for the light SOC fraction. Finally, the internal selective transport of one SOC fraction may explain the enhanced mineralization and reaggregation capacity of the deposited sediments.

Characterization of textile effluent treatment plant sludge and its industrial application in fired clay bricks with health risk assessment

The textile industry in Bangladesh faces environmental and health challenges due to the disposal of solid waste from Effluent Treatment Plants (ETPs). To address this issue, a study was conducted using soil from a brick industry near Dhaka, amending it with varying amounts of dry sludge to create clay bricks. The original soil had a loam texture and medium plasticity. The research found that adding 9 wt% of sludge resulted in Grade A commercial bricks with a compressive strength of 15.33 MPa and water absorption of 13.33 wt%, meeting BDS 208 standards. However, these sludge-incorporated bricks experienced more shrinkage during the burning process due to organic content, requiring additional soil to maintain conventional dimensions. Also, to assess the health hazards of these sludge-incorporated bricks, a leaching test was performed, revealing that no toxic heavy metals (Pb, Cd, Cr, Cu, Ni, and Zn) in the leachate exceeded the limits set by the United States Environmental Protection Agency (USEPA). The study indicates that textile ETP sludge can serve as a sustainable raw material for bricks, potentially reducing the environmental burden caused by textile sludge disposal by 28.75%. This innovative approach offers a promising solution to both environmental and health concerns associated with textile waste in Bangladesh's industrial sector.

Effect of soil organic amendments on sorption behavior of two insecticides and two herbicides

The effect of biochar, compost, peat and wheat straw at 1 and 5% on adsorption isotherm of chlorantraniliprole, dinotefuran, bispyribac-sodium, and metribuzin was studied in clay loam soil and sandy loam soil. Biochar, compost, peat and wheat straw (at a rate of 1 % in soil) improved the adsorption capacity of chlorantraniliprole and metribuzin in sandy loam soil. The sorption coefficients are higher for chlorantraniliprole and metribuzin whereas lower for dinotefuran and bispyribac-sodium in amended soil compared to unamended sandy loam soil. There is not a clear direct correlation between Freundlich parameters as well as Kd or Koc and type of organic amendment. The sorption of all tested pesticides on biochar was increased, whereas on compost was decreased. The order of pesticides sorption in soils and different organic amendments is generally inversely proportional to their aqueous solubilites. Adsorption of chlorantraniliprole increases on the sandy loam soil amendment at the rate of 1% in the following order: peat &gt; compost &gt; biochar &gt; original soil. Also, the magnitude of adsorption on soil A amendment at the rate of 5% can be arranged for dinotefuran in the order; peat &gt; biochar &gt; compost &gt; original soil and for bispyribac-sodium and metribuzin peat = wheat straw &gt; biochar &gt; original soil.

Initial microbiome and tree root status structured the soil microbial community discrepancy of the subtropical pine-oak forest in a large urban forest park.

Plant-microbe-soil interactions control over the forest biogeochemical cycling. Adaptive plant-soil interactions can shape specific microbial taxa in determining the ecosystem functioning. Different trees produce heterogeneous soil properties and can alter the composition of soil microbial community, which is relevant to the forest internal succession containing contrasting stand types such as the pine-oak forests. Considering representative microbial community characteristics are recorded in the original soil where they had adapted and resided, we constructed a soil transplant incubation experiment in a series of in situ root-ingrowth cores in a subtropical pine-oak forest, to simulate the vegetational pine-oak replacement under environmental succession. The responsive bacterial and fungal community discrepancies were studied to determine whether and how they would be changed. The pine and oak forest stands had greater heterogeneity in fungi composition than bacteria. Original soil and specific tree root status were the main factors that determined microbial community structure. Internal association network characters and intergroup variations of fungi among soil samples were more affected by original soil, while bacteria were more affected by receiving forest. Specifically, dominant tree roots had strong influence in accelerating the fungi community succession to adapt with the surrounding forest. We concluded that soil microbial responses to forest stand alternation differed between microbiome groups, with fungi from their original forest possessing higher resistance to encounter a new vegetation stand, while the bacteria community have faster resilience. The data would advance our insight into local soil microbial community dynamics during ecosystem succession and be helpful to enlighten forest management.