Soil Type Research Articles

Effects of Frozen Layer on Composite Erosion of Snowmelt and Rainfall in the Typical Black Soil of Northeast China

Composite erosion caused by snowmelt and rainfall causes considerable soil loss during spring thawing. However, research on the impact of frozen soil layers (FSL) on composite erosion is lacking. Therefore, indoor simulation experiments were conducted on soil conditions of 0 cm (unfrozen soil, FSLUN) and 3 cm thawing depths to explore the influence of FSL on composite erosion in the black soil region of Northeast China. Three snowmelt runoff (SR) discharges (0.34 L min−1, 0.5 L min−1, and 0.67 L min−1), three rainfall (RF) intensities (80 mm h−1, 120 mm h−1, and 160 mm h−1), and three snowmelt–rainfall interactions (SRI; 0.34 L min−1–80 mm h−1, 0.5 L min−1–120 mm h−1, and 0.67 L min−1–160 mm h−1) were used in this study. The results indicate that FSL advanced the initial erosion times of SR, RF, and SRI by 42.06%, 43.33%, and 45.83%, respectively. FSL increased the soil erosion rate (SER) of SRI by 1.2 (1.0–1.6) times that of unfrozen soil, which was smaller than that of SR (16.3, 5.6–25.0) and RF (1.7, 1.6–1.9), indicating that the interaction had an inhibitory effect on the increase in water erosion in the frozen layer. Under FSL and FSLUN conditions, RF erosion was 1.5–4.1 times and 14.5–24.3 times greater than SR erosion. The SRI erosion was not a simple linear superposition of multiple types of single-phase erosion; it had a significant nonlinear superposition amplification effect (SAE), with SAE of ~100% and ~300% under frozen and unfrozen soil conditions. Flow velocity (0.11 < R2 < 0.68), stream power (0.28 < R2 < 0.88), and energy consumption (0.21 < R2 < 0.87) exhibited significant (p < 0.05) linear relationships with SER in both FSL and FSLUN. The research results deepen our understanding of the composite erosion process during the spring thawing period in the black soil region of Northeast China and provide a basis for the prevention and control of soil erosion in the region.

Optimization-based stacked machine-learning method for seismic probability and risk assessment of reinforced concrete shear walls

Efficient seismic risk assessment aids decision-makers in formulating citywide risk mitigation plans, providing insights into building performance and retrofitting costs. The complexity of modeling, analysis, and post-processing of the results makes it hard to fast-track the seismic probabilities, and there is a need to optimize the computational time. This research addresses seismic probability and risk assessment of reinforced concrete shear walls (RCSWs) by introducing stacked machine learning (Stacked ML) models based on Bayesian optimization (BO), genetic algorithm (GA), particle swarm optimization (PSO), and gradient-based optimization (GBO) algorithms. The study investigates 4-, to 15-Story RCSWs assuming different bay lengths and soil types to build a comprehensive database based on the incremental dynamic analysis (IDA) subjected to 56 near-field pulse-like and no-pulse records. Having 227,200 and 63,384 data points for a median of IDA curve (MIDA) and seismic probability curve, respectively, the proposed Stacked ML models have shown good performance on curve fitting ability by accuracy of 99.1% and 99.4% for MIDA and seismic fragility curves, respectively. In addition, the proposed models can estimate the mean annual frequency, λ, which is a key parameter in seismic risk assessment of buildings. To provide the results of the study for general buildings, a user-friendly GUI is proposed that facilitates result utilization, offering insights into seismic performance levels, providing the estimated MIDA and seismic failure probability curves, and mean annual frequency calculations for specific performance levels and seismic hazard curves.

Revealing the Ground Deformation and Its Mechanism in the Heihe River Basin by Interferometric Synthetic Aperture Radar and Optical Images

The Heihe River Basin (HRB), located on the northeast margin of the Qilian Mountains, is China’s second largest inland river basin. It is a typical oasis-type agricultural area in northwest China’s arid and semiarid areas. It is important to monitor and investigate the spatiotemporal distribution characteristics and mechanisms of surface deformation in HRB for the ecology of inland river basins. In recent years, research on HRB has mainly focused on hydrology, meteorology, geology, or biology. Few studies have conducted wide-area monitoring and mechanism analysis of the surface stability of HRB. In this study, an improved interferometric point target analysis InSAR (IPTA-InSAR) technique is used to process 101 Sentinel-1 SAR images from two adjacent track frames covering the HRB from 2019 to 2020. The wide-area deformation of the HRB is obtained first for this period. The results show that most of the surface around the HRB is relatively stable. There are six areas with an extensive deformation range and magnitude in the plain oasis area. The maximum deformation rate is more than 50 mm/year. The maximum seasonal subsidence and uplift along the satellites’ line-of-sight (LOS) direction can be up to −70 mm and 60 mm, respectively. Moreover, we use the Google Earth Engine platform to process the multisource optical images and analyze the deformation areas. The remote sensing indicators of the deformation areas, such as the normalized difference vegetation index (NDVI), soil moisture (SMMI), and precipitation, are obtained during the InSAR monitoring period. We combine these integrated remote sensing results with soil type and precipitation to analyze the surface deformations of the HRB. The spatiotemporal relationships between soil moisture, vegetation cover, and surface deformation of the HRB are revealed. The results will provide data support and reference for the healthy and sustainable development of the inland river basin economic zone.

Carbon Storage Potential and Saturation Behavior of Soils As Influenced by Level of C Input and Soil Types in Indian Sub-Continent

ABSTRACT Agricultural soils have the potential to store C (carbon), thereby improving soil health, and contributing to climate change mitigation. However, the capacity of a soil to hoard C may be limited. We tested the C saturation behavior of agricultural soils belonging to predominant soil orders (Inceptisols, Entisols, Alfisols, Aridisols and Vertisols) in Indian Subcontinent. A mesocosm experiment in open environmental conditions was conducted with six rate of farmyard manure (FYM) addition (0, 2.5, 5.0, 10.0, 20.0 and 40 Mg ha−1) for three and half years and total carbon (TC) was analyzed. Addition of more than 10 Mg FYM ha−1 enhanced TC content of soil with the period of experimentation irrespective of soil orders. Application of C input of the agriculturally recommended addition of FYM in India at 5.0 Mg ha−1 maintained the soil TC content. Without addition of any C input, sometimes there was depletion in native carbon. With higher levels of C additions, all the soils did not show any evidence of C saturation, thereby suggesting their higher potential to additional C storage. Indian agricultural soils could contribute significantly toward achieving the target of “4 per 1000” initiative of the United Nations. Higher organic carbon in soils would make agroecosystems more resilient toward extreme climate events and sustain crops productivity thereby could help to meet the food demand of the ever-increasing population of the country in the years to come.

The microbiome structure and shifts in surface and subsurface soil horizon of Haplic Luvisol under different crops cultivation

The presented study investigated the comparative approach to evaluate prokaryotic and fungal soil communities in association with various plant crops along the genetic soil horizon using a high-throughput sequencing technique, with special emphasis on subsoils. We evaluate the diversity, abundance and structure of soil microbiome through the depth profiles in Haplic Luvisol (Cutanic) soil collected from lucerne, pear orchard, vineyard, and wheat crop. The structure of soil microbial communities differed due to crop type as well as depth of soil layer. Additionally, some basic physicochemical properties (e.g. total organic carbon - TOC, total nitrogen - TN, dissolved organic carbon - DOC, dissolved nitrogen – DN, pH, clay content) as well as mass and morphological parameters of the plant roots were determined. The highest clay content was noted in illuvial (Bt) horizons (in all profiles). The content of the studied C and N forms was the highest in the Ap horizon and in some subsurface layers and generally decreased with depth. Generally, the highest TOC, TN and DOC content was noted in the orchard profile, while the lowest occurred in the vineyard profile. The opposite trend was found for available Mg content. In turn, the highest DN was determined in the winter wheat profile. Overall, the decrease of the abundances of the most dominant phyla with depth was observed. Using a holistic approach via microbiome investigation of bacterial and fungal communities along soil horizon in a long-term land use with different plant cultivation, we showed that land management not only affect α-diversity but also shift the structure and the composition of bacterial and fungal communities in response to land use, in particular we identified the highest values of biodiversity indicators were found under lucerne and the lowest under vineyard. Future work needs to include the importance of soil type in shaping soil microbial communities under the same land use and plant cultivation, especially under subsurface soil layers.

In Situ Evolution of Ionic Sites at Clay Mineral Interfaces Facilitates Fluoride and Phosphorus Mineralization.

Soil minerals influence the biogeochemical cycles of fluoride (F) and phosphorus (P), impacting soil quality and bioavailability to plants. However, the cooperative mechanisms of soil minerals in governing F and P in the soil environment remain a grand challenge. Here, we reveal the essential role of a typical soil mineral, montmorillonite (Mt), in the cycling and fate of F and P. The results show that the enrichment of metal sites on the Mt surface promotes the mineralization of F to the fluorapatite (FAP) phase, thereby remaining stable in the environment, simultaneously promoting P release. This differential behavior leads to a reduction in the level of F pollution and an enhancement of P availability. Moreover, solid-state NMR and HRTEM observations confirm the existence of metastable F-Ca-F intermediates, emphasizing the pivotal role of Mt surface sites in regulating crystallization pathways and crystal growth of FAP. Furthermore, the in situ atomic force microscopy and theoretical calculations reveal molecular fractionation mechanisms and adsorption processes. It is observed that a competitive relationship exists between F and P at the Mt interface, highlighting the thermodynamically advantageous pathway of forming metastable intermediates, thereby governing the activity of F and P in the soil environment at a molecular level. This work paves the way to reveal the important role of clay minerals as a mineralization matrix for soil quality management and offers new strategies for modulating F and P dynamics in soil ecosystems.

The Effect of Ecological and Physiological Adaptation of Food Crops on Food Security in the Banyumas Highlands Region

This study aims to analyze the influence of ecological and physiological adaptations of food crops on food security in the highland area of Banyumas Regency. The research area includes Baturaden, Kedungbanteng, and Cilongok Districts, which are known to have a surplus of rice food reserves. Ecological adaptation includes how food crops adapt to specific environmental conditions at high altitudes, while physiological adaptation includes plant responses to factors such as temperature, humidity, and soil type. The data used in this study came from the Central Statistics Agency of Banyumas Regency in 2021. The results show that food accessibility, measured through physical and social access, has a significant correlation with food security. Physical and social access were significantly correlated with food security, with significance values of 0.046 and 0.017, respectively. The study concluded that the ecological and physiological adaptations of food crops play an important role in supporting food security in the Banyumas highlands, and that increased physical and social accessibility can improve food security stability in the region. Local governments need to focus on providing facilities and infrastructure that support food accessibility to ensure sustainable food security in the highlands.

Identification and Mapping of Flood Vulnerability in the Meninting Watershed, West Lombok

Flooding is the inundation of a flat area as a result of overflowing water from the surrounding area or an overflowing river. The largest river that crosses West Lombok Regency is the Meninting River. The Meninting watershed area as a catchment area has an area of 12,307.75 hectares. This research aims to identify and map flood-vulnerability areas in the Meninting Watershed. Data collection was carried out through a geographic information system (GIS) using overlay and scoring methods. The variables used to assess the level of flood vulnerability were land slope, soil type, rainfall, land cover, and geological aspects. The level of flood vulnerability is divided into three classes, namely not vulnerable, moderately vulnerable, and very vulnerable. The results show that of the 41 villages/sub-districts in the Meninting watershed, 34 villages/urban- villages with a coverage area of 8.21% were very vulnerable to flooding. The four villages that have the largest flood-vulnerable areas were the villages of North Ampenan (120.16 hectares), Midang (87.43 hectares), Dasan Griya (79.68 hectares), and Sesela (77.32 hectares). Around 56.24% of all villages/urban villages in the Meninting watershed were quite vulnerable to flooding and 35.55% of the area was not vulnerable.

Beyond the rootzone: Unveiling soil property and biota gradients around plants

Although the effects of plants on soil properties are well known, the effects of distance from plant roots to root-free soil on soil properties and associated soil organisms are much less studied. Previous research on the effects of distance from a plant explored specific soil organisms and properties, however, comparative studies across a wide range of plant-associated organisms and multiple model systems are lacking.We conducted a controlled greenhouse experiment using soil from two contrasting habitats. Within each soil type, we cultivated two plant species, individually and in combination, studying soil organisms and properties in the root centre, the root periphery, and the root-free zones.We showed that the distance from the cultivated plant (representing decreasing amount of plant roots) had a significant impact on the abiotic properties of the soil (pH and available P and N) and also on the composition of the fungal, bacterial, and nematode communities. The specific patterns, however, did not always match our expectations. For example, there was no significant relationship between the abundance of fungal pathogens and the distance from the cultivated plant compared to a strong decrease in the abundance of arbuscular mycorrhizal fungi. Changes in soil chemistry along the distance from the cultivated plant were probably one of the important drivers that affected bacterial communities. The abundance of nematodes also decreased with distance from the cultivated plant, and the rate of their responses reflected the distribution of their food sources.The patterns of soil changes along the gradient from plant to root-free soil were largely similar in two contrasting soil types and four plant species or their mixtures. This suggests that our results can be generalised to other systems and contribute to a better understanding of the mechanisms of soil legacy formation.

Post-earthquake rapid seismic demand estimation at unmonitored locations via Bayesian networks

AbstractPost-earthquake safety assessment of buildings and infrastructure poses significant challenges, often relying on time-consuming visual inspections. To expedite this process, safety criteria based on a demand-capacity model are utilized. However, rapid assessment frameworks require accurate estimations of intensity measures (IMs) to estimate seismic demand and assess structural health. Unfortunately, post-earthquake IM values are typically only available at monitored locations equipped with sensors or monitoring systems, limiting broader assessments. Simple spatial interpolation methods, while possible, struggle to consider crucial physical factors such as earthquake magnitude, epicentral distance, and soil type, leading to substantial estimation errors, especially in areas with insufficient or non-uniform seismic station coverage. To address these issues, a novel framework, BN-GMPE, combining a Bayesian network (BN) and a ground motion prediction equation (GMPE), is proposed. BN-GMPE enables inference and prediction under uncertainty, incorporating physical parameters in seismic wave propagation. A further novelty introduced in this work regards separating the near and far seismic fields in the updating process to attain a clearer understanding of uncertainty and more accurate IM estimation. In the proposed approach, a GMPE is employed for the estimation, and the bias and standard deviation of the prediction error are updated after any new information is entered into the network. The proposed method is benchmarked against a classic Kriging interpolator technique, considering some recent earthquake shocks in Italy. The proposed BN framework can naturally extend for estimating the probability of failure of various structures in a targeted region, which represents the ultimate aim of this research.

Spent Mushroom Substrate Improves Microbial Quantities and Enzymatic Activity in Soils of Different Farming Systems

Organic fertilizers, such as spent mushroom substrate (SMS), improve soil fertility, but studies comparing their effects on different agricultural soils are limited. In this study, the effects of standard, SMS and composed fertilizers on soils from conventional–integrated, organic and biodynamic farming were investigated. Soil samples were analyzed for microorganisms and the activity of β-glucosidase (β-GLU), β-1,4-N-acetylglucosaminidase (NAG), urease (URE), arylamidase (ARN), phosphatase (PHOS), acid phosphatase (PAC), alkaline phosphatase (PAH) and arylsulphatase (ARS). Biodynamic soil showed the highest microbial counts and enzyme activities, followed by organic and conventional soils. SMS significantly increased the number of microorganisms and enzyme activities, especially in biodynamic and organic soils. Seasonal variations affected all microorganisms and most enzymes in all soils, except NAG in conventional and organic soils. Biodynamic soil showed stable activity of enzymes and microorganisms throughout the year, indicating greater stability. This study concludes that soil microorganisms and enzyme activities respond differently to fertilization depending on the soil type, with SMS demonstrating beneficial effects in all tested soils.

A new SPT-CPT correlation by statistical analysis based on a database from Anhui, China

ABSTRACT The standard penetration test (SPT) and cone penetration test (CPT) are the 2 most commonly used in situ tests in geotechnical investigations. In this study, various existing SPT–CPT correlations were assessed based on the database of Anhui Province, China, using data from 802 pairs of SPT–CPT measurements. The results showed that the existing correlations from other regions were not suitable for the geological conditions in Anhui Province. A new SPT–CPT conversion model based on the S curve was proposed through statistical analysis. This model introduced the soil behaviour index (Ic ) to SPT–CPT correlations to involve the influence of soil types on data interpretation. Comparative analysis demonstrated that the proposed correlation had the highest accuracy compared to correlations found in the literature, with the highest R2 value and lowest RMSE. Also, to validate the proposed model further, an additional set of investigation data was collected in Wuhu, Anhui, to verify the correlation. The correlation was successfully applied to predict a range of soil properties using the transformed N60 values. The validation analysis confirmed the highest accuracy of the correlation and its ability to effectively predict soil properties, thereby assisting in geotechnical design.

Effects of vermicompost and mineral fertilizers on soil properties, malt barley (Hordeum distichum L.) yield, and economic benefits

AbstractSoil fertility depletion has significantly reduced the yields of various crops in Ethiopia, mainly the yield of malt barley in the district. To address this issue, integrated applications of vermicompost and mineral nitrogen (N) fertilizers were tested. Therefore, this study aimed to evaluate the effects of vermicompost and mineral nitrogen fertilizers application on malt barley yield (Hordeum distichum L.), soil properties, and economic benefits. The experiment was arranged in a randomized complete block design with three replications. The treatments were nine in various combinations of vermicompost (VC) and N fertilizer (N): (69 kg N; 0.79 t VC + 58.65 kg N; 1.59 t VC + 48.30 kg N; 2.39 t VC + 37.95 kg N; 3.19 t VC + 27.60 kg N; 3.98 t VC + 17.25 kg N; 4.78 t VC + 6.90 kg N; 5.31 t VC ha−1 and control). The highest soil pH was recorded by applying 5.31 t of vermicompost ha−1 alone. The highest total nitrogen (0.34%), available phosphorus (15.58 mg kg−1), grain yield (4950 kg ha−1), and net benefit (4255.74 USD) were recorded from the application of 2.39 t VC plus 37.95 kg N, while the highest soil organic carbon (3.38%) and cation exchange capacity (26.17 cmol (+) kg−1) were recorded from 3.19 t VC plus 27.60 kg N ha−1 compared to the control. This study concludes that applying 2.39 t VC and 37.95 kg N ha−1 in combination improves soil fertility, malt barley yield, and economic benefits for smallholder farmers in the study district and adopts this in similar soil types and agroecologies.

Effects of soil and phylogeny on sulfur and phosphorus concentrations in wild plants on volcanic and non-volcanic soils in Japan

ABSTRACT Andosols are soils characterized by relatively high sulfur concentrations, but also by their low phosphorus availability for crops and vegetables. We assessed the effect of soil type on the concentrations of sulfur and phosphorus in plants using handheld X-ray fluorescence (XRF) analysis on herbarium specimens collected from Andosols and non-volcanic soils in Japan. The sulfur concentrations in plants from Andosols were higher than plants from non-volcanic soils, but there was no significant difference between their foliar phosphorus concentrations. Only three specimens out of 1203 herbarium specimens were below the sulfur concentration (1000 mg kg−1) needed for adequate growth of crops, but about half of specimens were below that for phosphorus (2000 mg kg−1). The sulfur concentrations were high in herbaceous plants, especially in plants from the Brassicaceae and Liliaceae families. Overall, the results show that the sulfur concentrations in wild plants from Japan were higher in Andosols, with a low risk for sulfur deficiency. In contrast, the effect of soil type on the phosphorus concentrations in plants was small, and this may be explained because most wild plants grow under phosphorus-limiting conditions. Finally, the analysis reveals a strong correlation between sulfur and phosphorus concentrations in plants, suggesting the existence of a mechanism that controls the sulfur and phosphorus concentration ratios.

Assessment of the Levels of Pesticide Residues and Trace Metal Elements (TME) in Soils in the Cotton-Growing Region of North-West Benin

ABSTRACT The objective of the study was to evaluate the levels of pesticide residues and trace metal elements (ETM) in the soils of the cotton-growing zone in north-west Benin. The soils under cotton, maize and soybean were retained in a Complete Random Block design with 12 repetitions. 36 sites were sampled, with 12 of them being allocated to each crop. The analysis involved determining permethrin, cypermethrin, and glyphosate from soil samples taken by HPLC. The determination of Cd and Pb was carried out by mass spectrometry with inductively coupled plasma after organic matter destruction. A analysis of variance was used to compare soil types with the data obtained. Linear regression equation models were created to estimate trace metal elements values based on pesticide residue values. The results showed that the average amounts of permethrin (0.61 ± 0.03 µg/mg), cypermethrin (0.69 ± 0.07 µg/mg), glyphosate (0.82 ± 0.01 µg/kg), cadmium (Cd) (1.78 ± 0.21 µg/kg), lead (Pb) (1.04 ± 0.14 µg/kg) were higher (p < 0.05) in soils under cotton crops. As for lead, it can only be estimated using permethrin (Pb = 0.18 + 0.37 Per) or cypermethrin (Pb = 0.24 + 0.34Cy) or both with high determination coefficient R2 (R2= 82.01%).

Soil Type and Associated Microbiome Influence Chitin's Growth Promotion Effect in Lettuce

Chitin amendment of peat substrate has been proven effective in promoting lettuce growth and increasing phenolic compounds in lettuce seedlings. However, the effect of chitin soil amendment on lettuce growth in mineral soil remains unexplored. The effect of chitin amendment of mineral soil on lettuce growth and metabolite changes was investigated for the first time in the present study in comparison with chitin-amended peat substrate. Our findings showed that chitin addition in peat substrate increased lettuce head weight by approximately 50% at harvest, whereas this increase was 30% when chitin was added to mineral soil. Targeted metabolomics analysis indicated that chitin addition affected the phenolic compounds in lettuce seedlings, but this effect varied between soil types. Moreover, untargeted metabolomics analysis suggested that using peat substrate or mineral soil had a greater influence on produced lettuce metabolites than chitin addition. Rhizobiome analysis showed that specifically Mortierellaceae family members, known for chitin degradation and plant growth promotion, significantly increased in peat substrate upon chitin treatment. In mineral soil, three bacterial genera and five fungi, including known plant-growth-promoting genera, were significantly more abundant upon chitin treatment but Mortierellaceae family members were not. We assume that the observed effects primarily stem from soil characteristics and from chitin-induced alterations in rhizobiome composition, particularly the presence of Mortierellaceae members, leading to promoted lettuce growth. Despite the variability, chitin remains an environmentally friendly alternative to synthetic fertilizers in lettuce production, but its beneficial effects are dependent on rhizobiome composition, which should be considered before chitin application. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Impact of Stress Induced by Unfavorable Soil Conditions on the Germination, Seedling Developmentand Stress Tolerance Indices of Browntop Millet (Brachiaria ramosa L.)

Background: Browntop millet, a traditionally cultivated yet underutilized millet, is abundant in iron, zincand fiber. It can thrive in diverse soils and climates, adapting well to a broad spectrum of ecological conditions. Assessing the performance of Brown top millet in various challenging soils prevalent across Tamil Nadu could provide valuable insights into its adaptability and potential for cultivation in different soil conditions. The evaluation focuses on its germination, seedling growthand stress tolerance indices in these diverse soil environments. Methods: The pot experiment was carried out in the Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore during Kharif 2023 season. Six soil types were collected from different zones in Tamil Nadu and tested in a completely randomized design with four replications. Germination, seedling growth and stress tolerance indices were calculated by using standard formula. Result: Results of the investigation revealed that the treatment with sandy clay loam soils of Eastern Block 37B TNAU, Coimbatore (T1) recorded higher germination and seedling growth indices. The lowest values were recorded with the sodic soils of ADAC and RI, Trichy (T6). The higher stress tolerance indices were recorded with the heavy clay soils of Cotton Research Station (CRS), Veppanthattai, Perambalur district (T2)and acidic soils of Anaikatti, Coimbatore district (T3).

Landslide hazard zonation (LHZ) mapping of Doon Valley using multi-criteria analysis method based on remote sensing and GIS techniques

The occurrence of landslides is a costly and cataclysmic natural hazard that mainly occurs in hilly areas due to factors like earthquakes, cloud burst, extreme rainfall, human pressure, etc. leading to loss of biodiversity, property, and life. Effective and comprehensive landslide risk management is crucial to address landslide susceptibility. Utilizing remote sensing and Geographic Information System (GIS) techniques, this work focuses on the landslide hazard zonation (LHZ) mapping. The study is specifically conducted in the Doon Valley. These advanced technologies help in identifying and categorizing the areas prone to landslides. The Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM) data at 30 m resolution and Sentinel-2B data at 10 m resolution were used to perform the remote sensing and GIS operations in ArcGIS Software. Thematic layers such as Land Use/Land Cover (LULC), Slope, Geology, Soil Type, Elevation, Drainage Density, Vegetation, and Aspect were produced utilizing remote sensing and GIS data. The weighted overlay, a multi-criteria analysis method, was applied to assign attribute values to each thematic layer based on their importance, which was then combined to calculate the landslide hazard zone. The findings of this study demonstrate that landslides are more likely to occur near and above the Main Boundary Thrust/Fault (MBT). The high to very high hazard zone covers 16.64% of the total area, making landslides occurring more frequently. Additionally, the study found that the Doon Valley rivers’ upper segments are more susceptible to landslides than their lower segments. By integrating Remote Sensing and GIS techniques, it is possible to obtain extensive knowledge of regions prone to landslides. This information will be helpful for decision-makers and planners to reduce the impact of landslides in the near future.

Mapping of soil carbon balances changes in the dry tropical forest ecosystem in Pernambuco Brazil

Maps of soil and vegetation carbon stock dynamics resulting from changes in land use in tropical dry areas are still scarce and virtually absent for the Brazilian Northeast region. The few data available were built on a scale that does not allow their use for decision-making and precision farming applications. Based on soil and land use data, we developed a geographical information system to estimate and map carbon balances in the large (86.135 km2) semiarid region of Pernambuco state, Brazil. Maps of carbon stocks for soil and vegetation for the years 2000 and 2016 were created on the scale of 1: 100000, stratified by land use and soil types. In this period, 28% of the area had decreases in soil and vegetation C stocks, 57% had no significant changes and only 13% had increases. Most of the change was associated with converting the open native forest vegetation (Caatinga) into pastures. The net C loss was 291 million Mg, representing an average loss of 2 Mg C ha-1 year-1. Water bodies, urban areas, and other unclassified uses were not accounted for but amounted to only 2% of the area. Overall, the method proved to be a fast and feasible approach to monitoring carbon balances derived from land use changes on a regional scale.

Imidacloprid Uptake and Accumulation in Lettuce Plant (Lactuca sativa L. var. longipolia) and Its Effects on Abundance of Microbial Communities in Cultivated and Non-Cultivated Arid Soil

Systemic plant protection products, such as neonicotinoids (NIs), are capable of being translocated throughout a plant. Although NIs are less toxic to mammals, fish, and birds, their impact on microbial and non-target insects is of concern. This study investigates the uptake, translocation, and accumulation of the NI, imidacloprid (IMI), in romaine lettuce (Lactuca sativa L. var. longipolia). Exposing 15-day-old seedlings to “10 mg/L” of IMI, the effects on microbial communities in both cultivated (CS) and non-cultivated soil (NCS) were studied along with IMI translocation within plant tissues. The concentrations of IMI in soil varied temporally and between soil types after initial application, with a decrease from 2.0 and 7.7 mg/kg on the first day of sampling to 0.5 and 2.6 mg/kg on the final sampling day (day 35) for CS and NCS, respectively. The half-life of IMI soil was 10.7 and 72.5 days in CS and NCS, respectively, indicating that IMI degraded more quickly in CS, possibly due to smaller grain size, aeration, microbial degradation, and water flow. The accumulated concentrations of IMI in lettuce tissues ranged from 12.4 ± 0.2 and 18.7± 0.9 mg/kg in CS and NCS, respectively. The highest concentration of IMI was found in the shoots, followed by the roots, whereas the soil showed the lowest IMI residuals at the end of the trial. Soil bacteria and fungi were altered by the application of IMI, with a lower abundance index within the bacterial community, indicating a negative impact on the distribution of bacteria in the soil.