Soil Substrate Research Articles

Natural Synedrella Residues as a Growing Substrate Ingredient: An Eco-friendly Way to Improve Yield and Quality of Beet (Beta vulgaris) Microgreens

Microgreens are a new type of edible fresh vegetable salad which are harvested before the cotyledons have fully developed but before the real leaves have entirely emerged. Being new to the market, appropriate substrates which are economical have yet to be established in order to increase production. In order to increase the yields of beet microgreens, this study tested natural synedrella residues (aerial parts) as a growing media component. This investigation was carried out in 2022 at the Prayoga campus in Bengaluru to assess the effects of synedrella residues combined with growth substrates on the yield and quality of beet microgreens grown in a greenhouse. The growth parameters analysed were germination rate, height, fresh and dried weight, and quality of beet microgreens (chlorophyll a and b, carotenoids, microbial safety) grown on substrates of synedrella residues, vermicompost, red soil and coco peat in different combinations. Results showed that the presence of Synedrella nodiflora residues in the growing substrate has increased the yields, quality, germination rate and microbially safe for consumption. Beet microgreens grown on these substrates along with syndrella have minimal levels of microbiological contamination (total coliforms) as a result, they can be consumed as a healthy and safe fresh vegetable salad in the human diet. Results show that employing this natural material as a component in growing substrate could boost beet microgreens' yields and nutritional profile, leading to a sustainable approach.

Relationships between soil properties and species establishment in the restoration of mined soils in the Cerrado biome.

Restoring the ecosystems of the Cerrado biome is challenging considering the diversity of phytophysiognomies present in the biome, some of which are composed of species from different strata (herbaceous, shrubby, and arboreal), which increases the complexity of restructuring the floristic composition. Other factors was involved, such as soil quality, which directly influences the success of restoration, water storage, and nutrients, the financial costs, and a slow ecological process, due to the adverse circumstances found in the area. be restored. The strong anthropogenic interventions by mining processes reduce dramatically the physical and nutritional composition of the soil. We studied two restoration areas in Paracatu, Brazil, to examine their edaphic conditions six years after mining activities ceased and relate them to the status of the restoration process. In 2009, a Cerrado restoration were established in an area previously explored for gravel extraction. Plants were sampled and identified in 11 transects along the planting lines. The diameter base (DB) and total height (HT) were measured. The physical/chemical quality of the soil substrate was determined using a collection of samples in open trenches at four types of points: Cerrado (TC); dead plant pits (TM); seedling pits having living individuals of the most abundant species (TT); and those of the second-most abundant species (TE). Cecropia pachystachya Trécul and Tapirira guianensis Aubl. were most abundant and demonstrated the potential to thrive in areas degraded by mining having low mortality rates and growth at relatively DB and HT. The physical quality indicators in the gravel pits were not limiting, indicating that substrate preparation was efficient in this regard. The organic matter content in TM, TT, and TE was low in comparison to that of TC, and the chemical conditions in the TE pit substrates were similar to those in TM pits, suggesting C. pachystachya is a species with good plasticity, whereas T. guianensis is present in pits with higher levels of phosphorus.

Rapid In Vitro Propagation of Fig (Ficus carica L.) ‘Violette de Solliès’ Supported by Molecular and Microscopy Analyses

Ficus carica L. is a common fig that is an incredibly nutritional fruit, well-known for its medicinal and economic values. This study aims to establish an efficient protocol for the mass propagation of fig plantlets (Ficus carica L.) for the cultivar ‘Violette de Solliès’. Surface-sterilized shoot-tip explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of cytokinins (6-benzylaminopurine, BAP; thidiazuron, TDZ; kinetin, Kn; and zeatin, Zea). Induced shoots were rooted on Woody Plant Medium (WPM) with different concentrations of auxins (naphthalene-acetic acid, NAA; indole-3-acetic acid, IAA; and indole-3-butyric acid, IBA). Rooted explants were acclimatized in eight different soil substrates prior to cultivation in a commercial plot. The propagated plantlets were analyzed for genetic stability and clonal fidelity using RAPD and SCoT molecular markers, whereas scanning electron microscopy (SEM) was performed to observe the stomata morphology of post-acclimatized plants. MS media supplemented with 5.0 mg/L BAP was the optimal treatment for multiple shoot induction (15.20 ± 1.03 shoots), whereas the highest percentage of rooting (93.33%) was achieved in WPM supplemented with 3.0 mg/L IBA. Plantlets were successfully acclimatized in biochar soil with a survival rate of 100%. RAPD and SCoT analysis showed no polymorphism occurrences across six subculture cycles, whereas observations via SEM indicated normal stomata structures on the leaves of acclimatized plantlets. This study documents an efficient micropropagation protocol for Ficus carica cv. ‘Violette de Solliès’ for the production of uniformed and true-to-type plant stocks suitable for commercial propagation.

Gel-Forming Soil Conditioners of Combined Action: Laboratory Tests for Functionality and Stability.

The research analyzes technological properties and stability of innovative gel-forming polymeric materials for complex soil conditioning. These materials combine improvements in the water retention, dispersity, hydraulic properties, anti-erosion and anti-pathogenic protection of the soil along with a high resistance to negative environmental factors (osmotic stress, compression in the pores, microbial biodegradation). Laboratory analysis was based on an original system of instrumental methods, new mathematical models, and the criteria and gradations of the quality of gels and their compositions with mineral soil substrates. The new materials have a technologically optimal degree of swelling (200-600 kg/kg in pure water and saline solutions with 1-3 g/L TDS), high values of surface energy (>130 kJ/kg), specific surface area (>600 m2/g), threshold of gel collapse (>80 mmol/L), half-life (>5 years), and a powerful fungicidal effect (EC50 biocides doses of 10-60 ppm). Due to these properties, the new gel-forming materials, in small doses of 0.1-0.3% increased the water retention and dispersity of sandy substrates to the level of loams, reduced the saturated hydraulic conductivity 20-140 times, suppressed the evaporation 2-4 times, and formed a windproof soil crust (strength up to 100 kPa). These new methodological developments and recommendations are useful for the complex laboratory testing of hydrogels in small (5-10 g) soil samples.

Influence of Geotextile Materials on the Fractal Characteristics of Desiccation Cracking of Soil

In recent years, the irregular cracks formed during the damage evolution of civil engineering materials have been able to be quantitatively described by using fractals. In this study, the fractal characteristics of the desiccation cracking of soil were investigated under different substrate contact and permeability conditions through a natural drying test in the laboratory. Three kinds of base contact conditions of soil, namely, grease, geomembrane, and geotextile, were designed, and two samples for each contact condition, including one parallel sample, were used. The continuous drying experiment was carried out at a constant ambient temperature. The crack morphology under different spacings was analyzed quantitatively using digital image processing technology. The fractal dimensions of three soil substrate contact conditions (grease, geomembranes, and geotextiles) were between 1.238 and 1.93. When the crack network on the soil surface stops developing, the fractal dimensions under the three experimental conditions are 1.88, 1.93 and 1.79, respectively. In the final state of crack development, the crack intensity factor of the sample with grease at the bottom is 2.99% and 4.02% higher than that of the sample with geomembranes and geotextiles at the bottom, respectively. The residual water contents of the samples with bottom contact conditions of grease, geomembrane, and geotextile increase successively, which are 3.12%, 5.76% and 9.71%, respectively. The effects of interface friction and permeability on soil cracking behavior are analyzed, and the evolution characteristics and formation mechanisms of cracks in soil are revealed.

Addition Pinus massoniana fallen wood improved the growth of Plagiomnium acutum in a substrate cultivation

Soilless culture has been widely used in horticultural plant production, but little research has been done on bryophyte. In this study, we selected a cultivation substrate mixed and proportioned with garden soil, granular soil, grass charcoal soil, general-purpose nutrient soil, and decomposed grade II, III, and IV fallen wood of Pinus massoniana as the raw materials of soilless substrate to investigate its effects on the growth and physiology of Plagiomnium acutum. The results showed that the total porosity, water-holding porosity, and water-holding capacity of the mixed substrate containing fallen wood of P. massoniana were significantly higher than those of other cultivated substrates. The average cover of the P. acutum was significantly and positively correlated with the substrate’s total porosity and water-holding porosity. Chlorophyll content was highly significantly and positively correlated with the water holding capacity and total nitrogen content of the substrate. Among them, VIII decomposition grade Pinus massoniana fallen log:Vgrass charcoal soil = 1:1 (SW8) substrate had the highest overall evaluation index and the best overall growth condition of P. acutum. In summary, VIII decomposition grade Pinus massoniana fallen log:Vgrass charcoal soil = 1:1 (SW8) substrate can be the best substrate for cultivation of P. acutum. The addition of P. massoniana fallen wood to the soil substrate increased the total porosity, water-holding porosity, and water-holding capacity of the substrate, which was conducive to the growth of P. acutum and the increase of chlorophyll content.

Tree species is more effective than season dynamics on topsoil function andCO2emissions in the temperate forests

AbstractSoil respiration is one of the most important operations controlling carbon (C) erosion from territorial ecosystems and a useful index of whole underground allocation of C and stand efficiency. However, how tree species effects root (i.e., autotrophic respiration) and soil microbial respiration (i.e., heterotrophic respiration), based on precise experiential schemes, are still restricted, even though crucial to guide the selection of species for reforestation and C management purposes. This research was done to study how tree species effect soil characteristics and function at stand level and which are the main drivers of soil CO2emission in mixed temperate forests in northern Iran (Mazandaran province). Four most common tree species at the experimental site (Parrotia persica,Ulmus minor,Quercus castaneifolia, andPopulus caspica) that surrounded by same species, were selected. Around each selected tree, four replicates of soil and litter samples were taken from (30 × 30 × 15 cm) and mixed to characterize soil physicochemical characteristics (i.e., bulk density, texture, water content, pH, electrical conductivity, N, organic carbon, and available P, K, Mg, and Ca), basal respiration and substrate (i.e., D‐manitol, D‐glucose, L‐asparagine, L‐arginine, gluconic acid, quinic acid, succinic acid, malonic acid, D‐glucosamine, L‐glutamine) induced respiration. In the litter characteristics, total N, C (OC), and C/N ratio were measured. Our results confirmed that soil chemical properties are more sensitive to species composition than soil physical ones. Moreover, individual tree species in mixed deciduous forests strongly influence induced microbial respiration, independently of the used substrates. On the contrary, season was the major factor explaining variations of basal respiration.

Meadow-living walls: Creating attractive vertical greenery with meadow seed mixtures – Experiences and recommendations from a three year field trial

Living walls (LW) are a way to increase urban green infrastructure. Previous research has mainly focused on microclimatic cooling effect or the technical functioning of LW, while the development of autochthonous plant species and visual plant aspects for LWs have largely been neglected. In this study we focused on the possibility of establishing LWs by seeding, which is not used very often despite obvious advantages such as low costs, low maintenance requirements, and a high species diversity potential.Within a three-year field study in a temperate oceanic climate, we established a meadow-LW by sowing seed mixtures of >30 species on textile mats without soil substrate. After a pre-growing period with horizontal mats in the greenhouse, we placed the greened mats vertically on experimental walls exposed to the North, South, East, and West. We documented species coverage and visibility over time, growth height, and maintenance steps. After cutting, the vegetation recovered within a few weeks and we recommend one complete cut in summer and removing dead plant material after the frost period.From April to October, we observed an increasing growth height and vegetation coverage reaching >100%, followed by a decline till December. Differences of plant species composition and development between different expositions and study years were observed especially after the cold winter of 2017/2018.This study was able to demonstrate that seeded meadow-LWs can be easily established. The use of autochthonous plant species mixtures can create new biodiverse habitats, are aesthetically attractive and increase human wellbeing.

Seed traits inform the germination niche for biodiverse ecological restoration

Seeds are a primary source for generating plants for large-scale restoration and understanding the requirements for seed germination and establishment is fundamental to ecological restoration. Seed germination traits are central to defining the germination niche and identifying traits that may limit seedling establishment provides insights into how seeds may interact with the abiotic environment and the soil substrates specific to each restoration site and informs seed management practices. In this paper we review seed trait data derived from research to improve restoration practice across diverse ecosystems within Western Australia. We compile and evaluate seed trait data for up to 300 seed collections of 287 species that are used in restoration programmes to identify species, lifeform, and region-specific variation in seed dormancy, maximum germination, germination speed, base water potential, and germination niche breadth. Through a synthesis of this data, we outline our ecologically-guided approach to identifying key seed traits that support plant regeneration to improve the success of seed-based restoration across the biodiverse Western Australian landscape.

Phosphorus Nutrition and Water Relations of European Beech (Fagus sylvatica L.) Saplings Are Determined by Plant Origin

Climate change, specifically the increasing frequency and intensity of summer heat and drought, has severe influences on the performance of beech forests, including decline in growth, reduced nutrient turnover, enhanced mortality, and a shift in spatial distribution northwards and towards higher elevations. The present study aimed to characterize the physiological responses of Croatian beech saplings originating from 10 natural forest stands to experimentally applied water deprivation in a common-garden experiment. The aim was to evaluate the extent to which external factors such as climate, as well as nitrogen (N) and phosphorus (P) availability in the soil of the natural habitats, control the response of beech saplings to water deprivation. For this purpose, beech saplings from 10 forest stands that differed in terms of soil type, chemical soil properties, as well as climate were collected in winter, cultivated in an artificial soil substrate under controlled conditions for one year, and then subjected to 29 days of water deprivation. Responses to water deprivation were observed in the antioxidative system (total ascorbate, reduced ascorbate, oxidized ascorbate, and redox state) in leaves and fine roots. The latter allowed us to categorize saplings as adapted or sensitive to water deprivation. P over N availability in the soil rather than climatic conditions in the natural habitats controlled the response of beech saplings to the water-deprivation event. The categorization of saplings as adapted or sensitive to water deprivation was related to genetic parameters. The results of this multidisciplinary study (tree physiology, climate, and genetic data) are considered to be highly significant and beneficial for the adaptation of European beech forests to changing climatic conditions.

In vitro regeneration of Senna alata (L.) Robx. (Fabaceae): An ancient medicinal plant

Senna alata, a legume of medicinal importance, presents antifungal and antibacterial antioxidant activity. The main limitation is the presence of seeds with integument dormancy within natural populations. This study aimed to establish an efficient protocol for the in vitro propagation and acclimatization of seedlings. The seeds were disinfected with different concentrations of NaOCl; for the regeneration of the shoots, cotyledon segments were inoculated in MS and WPM medium, supplemented with plant growth regulators, auxins (1-NAA and 2,4-D), interaction with cytokinins (TDZ and BAP), and activated carbon. The seedlings were acclimated in nursery conditions using vermiculite, sand, and soil substrates. Using NaOCl (0.5%) for 30 min resulted in 98.0% disinfected seeds while 95.4% of scarified seeds germinated. High node and shoots numbers (8.3 ± 0.4; 12.6 ± 0.8, respectively) were obtained when using the MS medium containing 1-NAA + TDZ (0.1 + 1.0 mg L-1), while the use of MS medium supplemented with 2,4-D + TDZ (0.1 + 1.0 mg L-1) resulted in longer shoots (6.0 ± 0.5 cm). Using WPM medium with IBA + BAP (1.0 + 0.1 mg L-1) improved rooting (14.0 cm ± 1.3) and the number of roots (5.0 ± 0.0) in the treated plants. The vermiculite substrate with sand promoted 81.5% of acclimatized plants. This study allowed obtaining high levels of germination, regeneration in vitro and acclimatization of S. alata.

Surface wave attenuation by periodic hollow steel trenches with Bragg band gap and local resonance band gap

The use of phononic crystals and elastic metamaterials has been a significant concern as an efficient approach to attenuate the surface waves of ambient vibration and seismic vibration. In previous research, elastic metamaterials with periodic array of pillars or other forms of standing structures (such as H-fractal steel or built-up structural steel) erected on soil substrate can achieve a low frequency surface wave band gap (BG). However, such metamaterials with standing structures occupy land and affect the esthetics of cities, and buried metamaterials such as cross-like-cavity or hollow-cylinder structures with large size in soils necessitate continual maintenance for the stability of cavity soil structure. Thus, this study proposes two types of periodic hollow steel trenches exhibiting both a Bragg BG and a local resonance BG, the steel plates are used to support the soil on both sides of the trench to meet the stability requirements of cavity soil structure and avoid toppling or landslide of soils. The dispersion relations of periodic hollow steel trenches are calculated by using finite element method and the mechanism of generation for two kinds of BGs are interpreted by the eigenmodes. Furthermore, the effectiveness of periodic hollow steel trenches on isolating surface waves within the BGs is demonstrated in both frequency domain and time domain analysis. Several significant geometrical and material parameters on BGs that can affect the BG are studied as well. This study provides a new approach using the coupling effects of Bragg BG and local resonance BG to simultaneously attenuate the surface waves induced by the ambient and seismic vibration in a more practical way.

Sandy beach dwelling crickets (Orthoptera: Trigonidiidae) have no preference for substrates that match their body color

ABSTRACTHabitat choice is an important behavior for maximizing fitness. One of the factors involved in habitat choice is preference for habitat substrates. In the context of predatory avoidance, it is adaptive to prefer substrates that are matched to own body color. The ground cricket Dianemobius csikii (Bolívar, 1901) occurs on sandy beaches. The body color of D. csikii resembles the sand of their habitat, which could be a form of crypsis. If D. csikii is not able to choose a suitable habitat background that matches their body color, the crickets incur a high risk of predation. The risk could result in population decline of the cricket. To examine whether D. csikii shows preference for substrates that match its body color, we undertook a two‐choice test of sand or soil substrates after controlling the type of flooring substrates used during rearing. The crickets did not show preference for sand. There was no significant effect of flooring substrates during the nymph stage on the preference. These results suggest that when habitats are fragmented, crickets do not actively choose a cryptic background. There were significant differences in the substrate preference between sexes. These results reflect differences in the reproductive strategies of males and females.

К вопросу сохранения биоразнообразия пастбищных агроценозов сухих степей Нижнего Поволжья

Nowadays, more than 85% of pastures are depleted, they have low productivity and poor biodiversity. Therefore, the priority is the issue of stabilizing the productivity of pasture agrocenoses, increasing their longevity and species diversity. The purpose of the research is to develop effective methods for stabilizing and increasing the productivity of agrocenoses in natural conditions and on artificially created lysimeters of the hydrological complex of the Federal Scientific Center of Agroecology of the Russian Academy of Sciences. Reducing the load of small and large cattle on the pasture leads to the stabilization of the process of restoration of the vegetation cover of natural agrocenoses, but it is necessary to study all the mechanisms of soil degradation and develop a balanced and adapted range of pasture ecosystems. As a result of the research, a promising composition of polycomponent agrocenoses was selected, which is represented by herbs of the Stavropol selection, most of them are represented by the Poaceae family, in combination with Kochia prostrata (L.) Schrad., Artemisia arenaria D.C., and Eurotia ceratoides L. on lysimeters with a chernozem soil substrate, there are the best conditions for the growth and development of agrocenoses. The average productivity of green mass in terms of hay was 2.5 t/ha during the growing season. Over 70% of the phytomass is formed by grasses. On the light-chestnut sandy loam substrate on the pastures “spring – summer” and “summer – autumn” the lowest productivity of phytomass was noted – 2.2 t/ha. The results obtained will be used in the further study of the dynamics of soil degradation and the development of effective phytomeliorative measures leading to the conservation of the biodiversity of pasture agocenoses and their restoration in a changing climate.

Response of Carbon Emissions and the Bacterial Community to Freeze-Thaw Cycles in a Permafrost-Affected Forest-Wetland Ecotone in Northeast China.

Climate warming can affect freeze–thaw cycle (FTCs) patterns in northern high-latitude regions and may affect permafrost carbon emissions. The response of carbon release and microbial communities to FTCs has not been well characterized. Here, we conducted laboratory incubation experiments to investigate the relationships among carbon emissions, bacterial community, and soil variables in a permafrost-affected forest–wetland ecotone in Northeast China. The emission rates of CO2 and CH4 increased during the FTCs. FTC amplitude, FTC frequency, and patch type had significant effects on carbon emissions. FTCs increased the contents of soil DOC, NH4+-N, and NO3−-N but reduced bacterial alpha diversity. CO2 emissions were mainly affected by bacterial alpha diversity and composition, and the inorganic nitrogen content was the important factor affecting CH4 emissions. Our findings indicated that FTCs could significantly regulate CO2 and CH4 emissions by reducing bacterial community diversity and increasing the concentration of available soil substrates. Our findings shed new light on the microorganism-substrate mechanisms regulating the response patterns of the soil carbon cycle to FTCs in permafrost regions.

Разработка способа укоренения побегов грецкого и лесного орехов в культуре in vitro

In vitro biotechnologies are widely used to preserve biodiversity and produce high quality planting material. The main problem that hinders the development of micropropagation for nut crops is their low ability to in vitro root formation and the long period of plant adaptation when transferred to a soil substrate. The aseptic shoots of varieties and wild forms of Juglans regia L. and Corylus avellana L. in vitro micropropagated are used as plant material for this study. A comparison was made between two methods of in vitro rooting. For walnut, the use of a two-stage rooting method on Murashige-Skoog agar medium with high concentrations of indolyl 3 butyric acid (10 mg/l) and sucrose (60 g/l) (method I) made it possible to obtain an average of 68.6 % of rooted plants. The second rooting method, replacing agar with vermiculite, proved to be the most effective for hazelnut, with 91.3 % of Corylus avellana shoots rooting in vitro. The adaptation of hazelnut plants to the conditions of the greenhouse was successful, 91.8 % of the plants continued their development. In walnut, 28.6 % of plants adapted to the soil substrate.

Unravelling the role of soil microflora from micro and macro aggregates in plant growth during primary and secondary successions

The role of microbial communities from soil aggregates in grasses and herbs’ development during plant succession is not clear. We isolated microbial communities in micro- (<250 μm) and macro-aggregates (>250 μm) and investigated their inoculation on plant communities. Microbial inoculums were added to sterilized soil substrates from primary and secondary plant succession. Soil substrates were collected from primary plant succession included early (ca. 10 years) and late (ca. 65 years) substrates, and secondary plant succession included ancient permanent meadows since the last few thousand years and the same soils restored by secondary succession after being used as arable land.Results showed that during primary plant succession, the late substrates had higher plant biomass than the early substrates, especially when they received microbial communities from the early substrates. When transferred from donor to recipient substrates, bacterial community structure was depending both on the donor and recipient soil, but fungal community structure was mainly controlled by the donor soils and soil aggregates. Micro-aggregate inoculum from the early substrates promoted the growth of herbs, while macro-aggregate inoculum increased the growth of grasses in the late substrates.In contrast, plants grew better during secondary plant succession in ancient and restored soils when they retained their original microbial communities. Inoculum from the ancient soils did not benefit plant growth in the restored soils. Macro-aggregate inoculum from the restored soils had higher plant biomass than micro-aggregates in the ancient soils. Structural equation modelling showed that bacterial community composition (e.g. actinobacteria) significantly controlled total plant community biomass in the primary successional substrates.Overall, our study showed the effect of microbial community in soil aggregates on grasses and herbs’ community development.

Different mechanisms driving increasing abundance of microbial phosphorus cycling gene groups along an elevational gradient

SummaryMicrobes play an integral role in forest soil phosphorus (P) cycling. However, the variation of microbial P-cycling functional genes and their controlling factors in forest soils is unclearly. We used metagenomics to investigate changes in the abundance of genes involved in P-starvation response regulation, P-uptake and transport, and P-solubilization and mineralization along the five elevational gradients. Our results showed the abundance of three P cycling gene groups increasing along the elevational gradient. Acidobacteria and Proteobacteria were the dominant microbial phyla determining the turnover of soil P-solubilization and immobilization. Along the elevational gradient, soil substrates are the major factor explaining variation in P-starvation response regulation genes. Soil environment is the main driver of P-uptake and transport and P-solubilization and mineralization genes. This study provided insights into the regulation of P-cycling from a microbial functional profile perspective, highlighting the importance of substrate and environmental factors for P-cycling genes in forest soils.

TOXIC EFFECT OF LAMBDA CYHALOTHRIN AND PRETILACHLOR ON BIOMASS AND HISTOLOGY OF TESTIS OF Lampito mauritii (KINBERG)

Lambda cyhalothrin and pretilachlor is widely used to control agricultural pest but also affect non target organisms like earthworms. The present laboratory study was conducted to determine the effect of Lambda cyhalothrin and Pretilachlor on biomass and histology of testis of Lampito mauritii. Lower and higher sub-lethal concentrations of Lambda cyhalothrin (T1 and T2) and Pretilachlor (T3 and T4) was mixed with soil substrate. Biomass was observed once in 10 days up to 90 days. 10 non clitellate L.mauritii was introduced into each treatment. Soil substrate without lambda cyhalothrin and pretilachlor served as control. The present study was revealed that lambda cyhalothrin and pretilachlor was highly affected the growth of L. mauritii. For histopathology study, four adult L. mauritii were introduced in to C, T1, T2, T3 and T4. After 5th, 15th and 30th day, testis was dissected out. The results reported that histology of testis was highly damaged on 5th and 15th day of experiment than 30th day.

Spreading and shrinking behaviors of oil films with different viscosities on a cold immiscible liquid substrate

The spreading behavior of an oil film on an immiscible liquid substrate plays an important role in practical phenomena such as oil spills and thermal spraying. Especially in extremely cold regions such as the Arctic regions, the spreading behavior and balanced state of the spilled oil may be significantly affected due to the varying oil physical properties caused by the low temperature. The effect of low-temperature conditions on the spreading behavior remains poorly understood. The spreading experiments of silicone oils with viscosities of 50, 100, 350, and 1000 cs were carried out on cold substrates by controlling the liquid substrate temperature in the range of − 20 °C to 20 °C through a circulating bath. The effects of substrate temperature on the spreading morphology, equilibrium thickness, spreading rate and other parameters of the oil film were investigated. When the temperature was greater than 10 °C, silicone oils spread continuously, whereas when the temperature was less than 0 °C, some of them first exhibited a short period of shrinking behavior before spreading. The surface tensions at three interfaces, namely oil–air, oil–substrate, and substrate–air, were analyzed comprehensively. A novel equilibrium equation of the gravity-surface tension based on Neumann’s triangle rule was derived to calculate the stable thickness of the oil film, in which the contact angle at the three-phase junction was measured experimentally, and the quantitative relationship between the surface tension and temperature was considered. The calculated results were in excellent agreement with the experimental results. A modified prediction model was fitted to accurately describe the spreading velocity of the silicone oil by considering the effect of temperature on the viscosity and density. Finally, the variations in the temperature inside the oil film were discussed to explain the shrinking phenomenon. The study provides theoretical support for the creation of oil spill clean-up methods for low-temperature waters.