Bank Soil Research Articles

Competitiveness of chia against brassica weeds improves through a narrow spatial arrangement

Chia (Salvia hispanica L.) is a promising crop valued as a sustainable source of omega-3. However, chia yield and quality are reduced because of weed competition and the lack of registered herbicides. This study evaluated how chia spatial arrangement suppresses weed growth and provided management options for this crop. The performance of chia plants was assessed over three growing seasons in field experiments using a factorial design that considered spatial arrangement (narrow and wide), weed management (control without weeds, soil bank brassica (Brassica rapa L.), and sown brassica), and cover crop (with or without a rye (Secale cereale L.) cover crop during chia fallow). Chia and brassica are not complementary, leading to resource competition (relative yield total around 1) and negative effects on each other. A significant decrease in chia grain yield of 0.9% per unit increase in the percentage of weeds in total biomass was observed. As chia had a competitive advantage over brassica, the grain yield reduction was ameliorated with a narrow spatial arrangement. Narrow spatial arrangement promotes faster canopy closure during the early growth stages, decreasing light penetration and suppressing weed growth. The high extinction coefficient of chia (0.91) and the low critical LAI (3.3) contributed to this light interception behavior. Accordingly, to maximize chia productivity and profitability, a narrow spatial arrangement is an effective management strategy to suppress weeds. This study contributes valuable insights into chia-weed interactions and emphasizes the importance of sustainable crop management practices.

Seeds go up and down: The role of dung beetles in soil seed movement in the Southern Atlantic Forest of Argentina

Abstract The vertical movement of seeds performed by dung beetles from the soil bank and in animal faeces influences seed germination and the temporal dynamic of forest regeneration. While this process has been explored at the community level, the individual role of species is less understood. Here, we investigated the role of dung beetle size and seed size in this vertical movement under experimental conditions. We performed experiments using a gradient of dung beetle sizes and three sizes of artificial seeds (plastic beads) in two situations: inside faeces (secondary dispersal) and buried in the ground (soil bank). Through regression analysis, we related dung beetle size, seed size, and the initial position of seeds on the soil bank to the final position of seeds and their potential germination. For seeds in the soil bank, upward movement and exhumation were mainly of medium and large seeds, initially located at shallower depths, with larger beetles being primarily responsible for this movement. The downward movement was similar for all seed sizes. In dung seeds, the percentage of small seeds buried gradually increased with beetle size, while larger beetles made the main contribution for medium and large seeds. Besides, all seed sizes were buried at an average maximum bury depth of nearly 4 cm (the limit of the germination zone). The relative contribution of species depended on the interaction between dung beetles and seed sizes. Moreover, large dung beetles were essential for burying large seeds in the Southern Atlantic Forest.

Assessing river bank erosion on Majuli Island for strength and stability in resilient protection

ABSTRACT The present study addresses the issues and challenges of Brahmaputra river bank erosion near Majuli Island, Assam. For field study, the most vulnerable locations, namely (i) Ahatguri area, (ii) Okhala Chuk, (iii) Kamalabari ferry ghat, (iv) Cinnatoli Chapori and (v) Kandhulimari area are taken into consideration. Geometrical as well as geotechnical investigations were carried out to obtain detailed information for the stability analysis of river bank slopes of selected sites. Through 2-D finite element-based numerical tool PLAXIS2D, results indicated low stability of river bank due to low shear strength and ingress of moisture. To improve the strength and stiffness of the river bank soil, authors suggest a soil stabilisation technique using a Cement-Soil mixture with a 1:25 ratio (4%). The influence of improvement in the geotechnical properties was noted with the improvement in the stability of the river bank soil when assessed numerically. Results depicted that under ‘saturated and stabilized condition’, approximately 99% reduction in maximum total displacement and 55–85% reduction in maximum total strain was observed at all the five critical locations studied. Factor of safety values of stabilised bank was increased by 4.5 to 12 times, compared to the corresponding results obtained for ‘saturated and unstabilized’ condition.

Assessment of Cadmium, Chromium, and Lead Concentrations in Water, Bank Soil, Sediment, Plants, and Fish in Bagega Lake, Zamfara State, Northwest-Nigeria

Assessment of Cadmium, Chromium, and Lead Concentrations in Water, Bank Soil, Sediment, Plants, and Fish in Bagega Lake, Zamfara State, Northwest-Nigeria

Bank erosion under the impacts of fluvial erosion, frost heaving/freeze-thaw process of rivers in seasonal frozen regions

Bank erosion is a key feature of channel evolution in alluvial rivers, and will occur under the combined effect of hydraulic erosion and frost heave/freeze-thaw process of rivers in seasonal frozen regions. However, most research on bank erosion modeling has seldom considered the impact of the frost heave/freeze-thaw process. Therefore, the variation in the mechanical characteristics of riverbank soil under the freeze-thaw cycle was investigated firstly in the current research and then used in the modeling of bank erosion processes at typical sections of the Songhua River. Additionally, a sensitivity analysis of riverbank stability was conducted using orthogonal experiments. The results indicate that after 7 freeze-thaw cycles, the soil cohesion and internal friction angle of bank soil decreased by about 10%–47 % and 9%–19 %, respectively. Unlike lowland rivers, bank erosion of rivers in seasonal frozen regions is more likely to occur during the rising water period. The frost heaving/freeze-thaw process will make the bank stability safety coefficient Fs more quickly decrease to the unstable critical value. As compared with the case without considering the frost heaving/freeze-thaw process, the mass failure occurred in advance when the frost heaving/freeze-thaw process was considered, and the calculated bank erosion volume was increased by 11%–51 %, agreeing better with the measured value. The sensitivity ranking of the four influencing factors on riverbank stability under freezing-thawing conditions is as follows: river stage > groundwater level > cohesion > internal friction angle. The current study can provide a reference for research on bank erosion and channel evolution of rivers in seasonal frozen regions.

Influence mechanism of herbaceous plants on debris flow bank erosion

The importance of implementing vegetation measures to mitigate debris-flow disasters is widely recognized. However, the specific role of herbaceous plants, especially those flourishing on the banks of debris-flow channels, in mitigating lateral erosion remains insufficiently understood. This study aims to elucidate the impact of herbaceous plants on bank erosion during debris-flow surges. In the experiment, Cymbopogon citratus (DC.) Stapf growing on the channel banks was cultivated for 20 to 100 days. Accordingly, the leaf area index (LAI) of plants ranged from 0.10 to 3.21, and the root length density (RLD) in the topsoil varied from 2.5 to 135.5 km/m3. In addition, the banks with plants were subjected to scouring by multiple debris-flow surges in a specially designed flume. The findings demonstrated a significant reduction in the erosion efficiency of debris flow on grassland banks, with reductions ranging from 70.84 % to 92.49 %, in comparison to bare soil banks. This reduction is attributed to the combined influence of two parts: leaves and roots. On one hand, the leaves partially shielded the shear stress of the debris flows. Under the impact of the debris flows, plants quickly fell down, with their leaves covering the soil. Lodging plants absorbed a portion of the shear stress from debris flow and transmitting it to the deeper soil through stems and roots. This process mitigated erosion on the topsoil. The erosion efficiency exhibited an exponential decline with increasing LAI. On the other hand, the roots altered the pattern of the soil erosion. Debris flows eroded soil from the gaps in the root systems with rarely cutting roots off, which means the layered shear failure of soil was suppressed. Additionally, the erosion efficiency exponentially decreased with the increase in RLD.

Flow structures in large-scale bank erosion zone of Lower Yangtze River

The bank erosion process in the densely populated Lower Yangtze River can pose a great threat to riparian residents and industries. It is characterized by rapid development within a few hours, a large-scale soil collapse of 106 m3, and an arc shape. During its development, flow field inside the bank erosion area continuously evolves and interacts with the bank soil. However, the mechanisms behind the bank erosion process are still unclear. Therefore, laboratory experiments were conducted to investigate flow structures and turbulences inside bank erosion areas. A pulsed particle image velocimeter was employed to obtain high-quality velocity data inside the bank erosion zone. Results show that the bank erosion zone can be divided into a backflow zone, a mixing zone, and a mainstream zone, according to variations in flow structure; in the mixing zone, water flow is highly turbulent, and the mixing width gradually increases downstream because of the shear effects between the mainstream and backflow; the backflow zone can be subdivided into a central zone and a peripheral zone, based on the pattern of velocity changes along the radial axis from the backflow center to its periphery. A formula for calculating the flow velocity within the backflow zone was proposed, and we found that the velocity gradient in the peripheral zone was approximately four times higher than that in the central zone. This indicated that shear stress exerted by the flow near the backflow boundary was significantly intensified.

Experimental Study on the Effect of Flow Velocity and Slope on Stream Bank Stability (Part I)

The erosion of riverbanks is a significant and capricious national concern. The Al Muwahada channel in Iraq experiences instability in its banks, resulting in failure, retreat, and morphological alterations. These issues are mostly caused by factors such as the velocity of the flow, the angle of the slope, and type of soil. This study investigated the behavior of canal bank soil in response to erosion and variations in slope angle. Therefore, a physical model of a case study was established in the laboratory. Additionally, a slope angle of 26˚ is being utilized, which has not been previously studied in the laboratory. This angle will be tested with five different velocity values: 0.101 m/s, 0.116 m/s, 0.12 m/s, 0.13 m/s, and 0.135 m/s. The bank's deformation was measured for a period of 12 hours, which was divided into 4 equal intervals for each velocity. The study determined that a riverbank with a slope of 26˚ is more resistant to erosion when the velocity of the water is below 0.12 m/s. Velocities equal to or greater than 0.12 m/s have a substantial impact on the erosion of the riverbed. According to this study, a velocity of 0.12 m/s or higher leads to increased erosion of the riverbank. This is equivalent to a velocity of 0.804 m/s in the prototype channel. The section of the riverbank that has suffered the greatest damage due to erosion is the upper two-thirds. The used methodology supports global efforts to increase information about the behavior of river banks with unexplored rivers that have different flow velocities and bank slope angles. Doi: 10.28991/CEJ-2024-010-08-013 Full Text: PDF

Predicting wave erosion rates of soil bank based on energy method

Predicting wave erosion rates of soil bank based on energy method

Effects of Phloretin on Seedling Growth and Histochemical Distribution of Phenols, Polysaccharides and Lipids in Capsella bursa-pastoris (L.) Medik.

The present study evaluates the phytotoxic effects of phloretin, a prevalent secondary metabolite of apple trees, on the broadleaf weed Capsella bursa-pastoris (L.) Medik. known for its resistant myxospermous seeds that form a long-lasting soil bank. The results indicate a significant, dose-dependent inhibitory effect of phloretin on the growth and morphological parameters of weed seedlings grown in vitro. Although the applied phloretin concentrations (250-1000 µM) were not lethal to the C. bursa-pastoris seedlings after two weeks, the metabolism of the seedlings was impaired, resulting in an accumulation of lipid droplets in the root tips and root hairs. Histochemical analysis shows deposits of phenols in the root epidermal cells, which are probably aggregates of phloretin or its metabolic derivatives. The accumulation of pectin in the cell walls of root border cells in phloretin-treated seedlings indicates an attempt to reduce the uptake of phloretin and reduce its concentration in the cells. Inhibition of shoot growth associated with chlorosis and reduced photosynthetic pigment content is a consequence of seedling exposure to phloretin. This study provides a basis for further evaluation of phloretin as a new bioherbicidal compound and for elucidating the mechanism underlying its phytotoxic activity.

Bank Retreat Mechanisms Driven by Debris Flow Surges: A Parameterized Model Based on the Results of Physical Experiments

AbstractLateral erosion is a critical factor that influences the formation and amplification of debris flows. However, our understanding of the bank retreat process in debris flow channels is limited, which limits the evaluation of debris flow magnitudes and the prediction of their activity trends. Herein, we conduct physical experiments to investigate bank retreat mechanisms using five types of bank soil and multiple debris flow surges. The bank retreat process is categorized into two stages: toe cutting and bank collapse. Toe cutting is mainly caused by hydraulic erosion, bank collapse includes gravity erosion in the form of toppling failure. Notably, the bank retreat process exhibits a significant negative feedback loop. Bank erosion widens the channel bed, subsequently decreasing the flow depth. In turn, this reduction in flow depth mitigates bank erosion. Moreover, we discover a concise pattern in the complex coupling of hydraulic erosion and toppling failure: erosion efficiency is linearly and negatively correlated with the bed widening width. We develop a new parameterized model for describing the bank retreat process and provided empirical values for the model parameters. Furthermore, we observe that the initial erosion efficiency first increases and then decreases with an increase in the fine particle content of the bank soil. Additionally, we report a negative correlation between the maximum bed widening width and the fine particle content in the bank soil that follows a power function relationship.

The Impact of Sorbent Amendments for Mercury Remediation on the Viability of Soil Microorganisms

Mercury (Hg) remediation across contaminated environments in the United States is an ongoing project. As part of the Hg cleanup strategy at East Fork Poplar Creek (EFPC), located in Oak Ridge, TN, the deployment of sorbents is considered. However, the impact of sorbents on soil microorganisms is poorly understood. In this study, we investigated the effect of sorbents on soil microorganism viability and biofilm formation to assess soil health during sorbent application for Hg remediation. We specifically investigated the effect of two engineered sorbents, Organoclay PM-199 and Organoclay MRM (which are manufactured from clay minerals formulated for various remediation applications), on two gram-negative organisms (Serratia marcescens and Burkholderia thailandensis) isolated from the Hg-contaminated EFPC bank soil. Pure cultures of S. marcescens or B. thailandensis were amended with 5% (w/v) and 25% (w/v) PM-199 and MRM, respectively, for 9 days. The samples were harvested, and bacterial cell viability was determined using a BacLight staining kit. Results showed that the growth of sorbent-amended S. marcescens was inhibited in contrast to that of unamended control. Furthermore, biochemical assays were used to analyze bacterial biofilm formation and integral biofilm components. Our results suggest that biofilm formation by sorbent-amended S. marcescens was negatively affected. In contrast, B. thailandensis amended with low concentrations of MRM showed enhanced growth and notable differences in biofilm morphology. These results suggest that the use of organoclay PM-199 and MRM at higher concentrations in field studies may hinder the growth of specific soil microorganisms.

Effects of naturally sourced bitumen samples from Alberta oil sands region (Canada) on aquatic benthic invertebrates: A case study with Chironomus riparius

Athabasca oil sands in Alberta, Canada, are large bitumen deposits and are one of the world's largest petroleum reserves. This research contributes to the growing body of knowledge on the influence of this naturally occurring bitumen on freshwaters. Using laboratory-based exposure studies, we examined the life cycle responses of the aquatic midge Chironomus riparius to both naturally formed solid bitumen incorporated in the sediment and its corresponding aqueous extracts, denominated as elutriates. The 28-day partial life cycle assay involved bitumen samples from two distinct geological origins in the Athabasca River Basin (Clearwater and McMurray formations), comprising both weathered and freshly collected bitumen from a total of 4 different rivers. Our results demonstrate a measurable impact of sediment-embedded bitumen on C. riparius life history traits, namely on their growth and emergence patterns. Furthermore, we observed that bitumen samples from the Ells River (McMurray formation), which were freshly collected from exposed river bank soil deposits, exerted the strongest effects on most studied eco-physiological endpoints. Bitumen extracts from the Steepbank River and Athabasca River in the McMurray Formation and Steepbank River in the Clearwater Formation followed, underscoring the geographical variance in bitumen-induced toxicity. Exposure to elutriates, simulating “weathered” bitumen generally did not induce adverse effects in C. riparius life-cycle endpoints compared to elutriates prepared from freshly eroded bank soils. This emphasizes the importance of considering bitumen sources, their age, and the aquatic receiving environment when assessing potential adverse exposure effects. Our study shows that exposure to freshly eroded soils/sediments can potentially affect benthic invertebrates. More research is needed to understand how hydrological changes affect bitumen sediment exposure and the associated risks to aquatic biota.

Complete genome of Acinetobacter calcoaceticus AC001_UM from Red River soil banks in Winnipeg, Manitoba, Canada.

We report the whole-genome sequence and antibiotic-resistance gene profile of an Acinetobacter calcoaceticus isolate, designated AC001_UM, taken from soil along the Red River in Winnipeg, Manitoba, Canada. The genome comprised 3,916,544 nucleotides (GC content: 38.7%). Antibiotic-resistance gene analysis revealed a class D β-lactamase and three efflux pump families.

Effects of freeze–thaw on bank soil mechanical properties and bank stability

Riverbank instability in the seasonally frozen zone is primarily caused by freeze–thaw erosion. Using the triaxial freeze–thaw test on the bank of Shisifenzi Bend in the Yellow River section of Inner Mongolia, we investigated the changes in the mechanical properties of the soil at different freezing temperatures and freeze–thaw times, and analyzed the bank’s stability before and after freezing based on the finite element strength reduction method. The results showed that the elastic modulus, cohesion, internal friction angle and shear strength of the soil tended to decrease with the increase in the number of freeze–thaw cycles and the decrease in freezing temperature. After 10 freezing cycles at − 5 ℃, − 10 ℃, − 15 ℃ and − 20 ℃, the modulus of elasticity of soil decreased by 40.84 ~ 68.70%, the cohesion decreased by 41.96 ~ 56.66%, the shear strength decreased by 41.92 ~ 57.32%, respectively. Moreover, the stability safety coefficient of bank slope decreased by 18.58% after freeze–thaw, indicating that the freeze–thaw effect will significantly reduce the stability of bank slope, and the bank slope is more likely to be destabilized and damaged after freeze–thaw.

IMPACT OF SOIL STERILIZATION FROM DIFFERENT LOCATIONS, WHEAT SEEDS CLEANING AND THEIR INTERACTIONS ON WEED CONTROL, AND YIELD AND YIELD COMPONENTS

IMPACT OF SOIL STERILIZATION FROM DIFFERENT LOCATIONS, WHEAT SEEDS CLEANING AND THEIR INTERACTIONS ON WEED CONTROL, AND YIELD AND YIELD COMPONENTS

Feasibility of constructed soils for tree planting – A pilot study in New York City

Constructed soils are soils that are created with a mixture of various materials. An innovative soil exchange program - the Clean Soil Bank (CSB) in New York City allows recycling of clean glacial outwash sediments excavated from depth at construction sites. One previous study showed that soils constructed from CSB sediment and compost can effectively support crop growth in community gardens, but no research has been conducted on its potential usage as a medium for tree growth. Moreover, biochar has been used to improve soil quality, but its efficacy for street trees incorporated into constructed soils has largely not been quantified in the field. The objective of this project was to evaluate the feasibility of using soils constructed from the CSB and compost for tree planting and to investigate the impact of biochar on tree performance. Thirty-six trees of two species (Maackia amurensis and Zelkova serrata) were planted in 2019, on the sidewalks of a residential-business neighborhood in Bronx, New York. Each tree pit contains one of three soil types: type A - existing and purchased topsoil mixed with 33% compost and biochar, type B - CSB sediment mixed with 33% compost, and type C - CSB sediment mixed with 33% compost and biochar. Soil samples were collected in 2019 (before planting) and in 2021. Tree health assessments were conducted in September 2020 and July 2021 using a protocol developed by the USDA Forest Service. Other tree health parameters collected include diameter at breast height (DBH), crown diameter, tree height, photosynthetic capacity, and foliar chemistry. Significant differences in bulk density, water holding capacity, and K, Fe, and Zn concentrations were found among the three soil types. However, comparison of tree performance and foliar chemistry showed no systematic differences among the three soil types. The results indicate that CSB sediment mixed with compost can be an effective replacement for purchased topsoil for tree growth. No evidence was found that biochar provides additional benefits to street tree performance. Considering the abundant availability of glacial outwash sediment at low cost to the city, as well as access to locally produced compost, constructed soils can be a reliable source of material for urban forestry programs.

The role of tidal creeks in shaping carbon and nitrogen patterns in a Chinese salt marsh

Tidal creeks play a crucial role in lateral transport of carbon and nutrients from tidal salt marshes. However, the specific impact of tidal creek development on carbon and nutrient distribution within the marsh remains poorly understood. The objective of this study is to assess the influence of lateral tidal flooding through the tidal creeks on the spatial distribution of carbon and nitrogen fractions in the soils of a Chinese temperate salt marsh. We conducted a comprehensive analysis of the relative variations in different carbon and nitrogen fractions, along with soil physicochemical and microbial indicators, between the bank soil of the tidal creek and its lateral inland soils across high, middle, and low flats. Our findings highlight that tidal creek development significantly affects the middle flat, leading to substantial variations in organic carbon and total nitrogen. The low flat mainly experiences changes in dissolved inorganic carbon levels. Furthermore, a lateral increase in microbial biomass is observed in the middle flat, indicating that the significantly lower SOC in the middle flat might be ascribed to enhanced microbial decomposition. The lateral enrichment of dissolved inorganic carbon in the low flat is possibly related to the nearshore location and/or abiotic adsorption in inorganic carbon sequestration. Overall, this study demonstrates the critical role of tidal creek development in shaping the distribution patterns of carbon and nitrogen fractions in tidal salt marshes.

Effect of Intercropping by Flax, Radish and Fenugreek on Faba Bean, <i>Vicia faba</i> L., Production and Reduction of <i>Orobanche crenata</i> Forsk Seed Bank

Faba bean <i>Vicia faba</i> L. is a primary source of protein in the diet of masses in Egypt. Broom-rape, <i>Orobanche crenata</i> Forsk (Orobanchaceae), present great threat parasitic weed to some crops in Egypt including faba bean. Egyptian farmers were forced to abandon growing faba bean crops due to <i>O. crenata</i> heavy soil infestation. Several methods have been used for controlling this parasite, but without obvious success. Many researches have shown that intercropping has been more effective than monocropping in suppression of parasitic weeds. The effect of intercropping (fenugreek, radish and flax) using two resistant cultivars (Giza 843& Misr 3) on the emergence of the broomrape spikes and faba bean production were carried out. Intercropping flax or fenugreek among faba bean cultivars, caused a significant reduction in the infestation levels of <i>O. crenata</i> and increased the faba bean yield compared with sole treatments. Flax was more effective in the reducing infestation rate by <i>O. crenata</i> than fenugreek. This reduction appeared to be related to reduced seed germination which may have been as a result of allelochemicals released by fenugreek roots, though this was not confirmed in this study. The reduction in weed infestation was more pronounced in Giza 843, than in Misr 3. Flax treatment showed the lowest weed infestation compared with other intercropping treatments. Fenugreek intercropping treatment resulted in the highest pod yield for both Giza 843 and Misr 3. Using resistant cultivars intercropping with fenugreek or flax is very promising trend that generally combines both good yield and low number of emerged spikes that reduce broomrape seed bank in the infected soils, with variations depending on the cultivar and growing season.

Experimental investigation of the efficiency of stone revetment for different temporal variations with the static water condition

Abstract The objective of this study is to determine the optimum size of stone revetment for different water standing durations and critical drawdown rates for 80% height of flood. The model bank was constructed using soil sourced from the Parlalpur ferry ghat of the Ganga River in Kaliachak, West Bengal, with a field density of 1.5 g/cc achieved by maintaining a 10% moisture content (MC) in the model bank soil. The model river bank was prepared considering Froude (F) similitude having a distorted depth scale of 1/20 and a linear scale of 1/200. In this study, effective stone sizes (D10) – 2.3, 3.22, 4.58, 6.31, and 8.84 mm – were used. These stone sizes were investigated in conjunction with three water standing durations: 15, 30, and 45 min. The bank slope was prepared at 1V:1.5H, and a drawdown ratio of 80% was maintained. The effectiveness of stone revetment size was analysed in terms of the percentage loss of stone revetment and the percentage loss of the model bank's cross-sectional area. The outcomes of this study indicate that the 6.31 mm stone size exhibits optimal performance.