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Accurate initial soil conditions play a crucial role in simulating soil hydrothermal and surface energy fluxes in land surface process modeling. This study emphasized the influence of the initial soil temperature (ST) and soil moisture (SM) conditions on a land surface energy and water simulation in the permafrost region in the Tibetan Plateau (TP) using the Community Land Model version 5.0 (CLM5.0). The results indicate that the default initial schemes for ST and SM in CLM5.0 were simplistic, and inaccurately represented the soil characteristics of permafrost in the TP which led to underestimating ST during the freezing period while overestimating ST and underestimating SLW during the thawing period at the XDT site. Applying the long-term spin-up method to obtain initial soil conditions has only led to limited improvement in simulating soil hydrothermal and surface energy fluxes. The modified initial soil schemes proposed in this study comprehensively incorporate the characteristics of permafrost, which coexists with soil liquid water (SLW), and soil ice (SI) when the ST is below freezing temperature, effectively enhancing the accuracy of the simulated soil hydrothermal and surface energy fluxes. Consequently, the modified initial soil schemes greatly improved upon the results achieved through the long-term spin-up method. Three modified initial soil schemes experiments resulted in a 64%, 88%, and 77% reduction in the average mean bias error (MBE) of ST, and a 13%, 21%, and 19% reduction in the average root-mean-square error (RMSE) of SLW compared to the default simulation results. Also, the average MBE of net radiation was reduced by 7%, 22%, and 21%.

Oil tea Camellia, as a major cash and oil crop, has a high status in the forestry cultivation systems in China. To meet the current market demand for oil tea Camellia, its potential distribution and suitable soil condition was researched, to instruct its cultivation and popularization. The potential distribution of oil tea Camellia in China was predicted by the maximum entropy model, using global environmental and soil databases. Then, we collected 10-year literature data about oil tea Camellia soil and applied multiple imputation and factor modeling for an in-depth analysis of soil suitability for growing of oil tea Camellia. The prediction indicated that oil tea Camellia was mainly distributed in Hunan, Jiangxi, Zhejiang, Hainan, East Hubei, Southwest Anhui and most of Guangdong. Climatic factors were more influential than soil factors. The minimum temperature of the coldest month, mean temperature of the coldest quarter and annual precipitation were the most significant contributors to the habitat suitability distribution. In the cultivated area of oil tea Camellia, soil fertility was poor, organic matter was the most significant factor for the soil conditions. Based on climatic and soil factor analyses, our data suggest there is a great potential to spread the oil tea Camellia cultivation industry.

Local soil conditions play a significant role in the intensity variations of seismic waves during earthquakes. These variations can be either amplified or de-amplified depending on the specific soil conditions. This study aimed to assess the impact of different soil profiles on seismic site responses. The study considered four types of site profiles: sand (Sa), clay (Cl), sand overlying clay (SaCl), and clay overlying sand (ClSa) profiles. To simulate the ground motion, we selected seven sets of strong earthquake records from the European Strong-Motion Database. These records were selected according to Eurocode-8 with a peak ground acceleration (PGA) of 0.24 g, site class A using REXEL computer program. The records were then applied to the bedrock at a depth of 30 meters. Subsequently, a series of 1-D equivalent linear (EQL) response analyses were performed using the STRATA. Amplification factors (AFs) and surface acceleration time histories provided quantitative evaluations for our analysis results. The results demonstrated that site profiles with clay overlying bedrock (SaCl and Cl profiles) exhibited higher seismic amplification and peak ground acceleration in comparison to site profiles with sand overlying bedrock (Sa and ClSa profiles). The maximum median AF is calculated from the SaCl site profile, while the minimum median AF was calculated from the ClSa profile. The relative difference between the maximum and the minimum median AFs was about 33.7%. Based on these results, we can conclude that soft local soils have a pronounced effect on the amplification of seismic waves compared to stiff local soils.

Natural soil has the ability to suppress the soil-borne pathogen to a certain extent, and the assemblage of soil microbiome plays a crucial role in maintaining such ability. Long-term monoculture accelerates the forms of soil microbiome and leads to either disease conducive or suppressive soils. Here, we explored the impact of soil conditions on bacterial wilt disease (healthy or diseased) under long-term tobacco monoculture on the assemblage of bacterial and fungal communities in bulk and rhizosphere soils during the growth periods. With Illumina sequencing, we compared the bacterial and fungal composition of soil samples from tobacco bacterial wilt diseased fields and healthy fields in three growth periods. We found that Proteobacteria and Ascomycota were the most abundant phylum for bacteria and fungi, respectively. Factors of soil conditions and tobacco growth periods can significantly influence the microbial composition in bulk soil samples, while the factor of soil conditions mainly determined the microbial composition in rhizosphere soil samples. Next, rhizosphere samples were further analyzed with LEfSe to determine the discriminative taxa affected by the factor of soil conditions. For bacteria, the genus Ralstonia was found in the diseased soils, whereas the genus Flavobacterium was the only shared taxon in healthy soils; for fungi, the genus Chaetomium was the most significant taxon in healthy soils. Besides, network analysis confirmed that the topologies of networks of healthy soils were higher than that of diseased soils. Together, our results suggest that microbial assemblage in the rhizosphere will be largely affected by soil conditions especially after long-term monoculture.

As an important cash crop, Nicotiana tabacum’s yield and quality are influenced by various factors, yet the correlations between its health status, microbial community, and environmental factors remain largely unexplored. In this study, we analyzed the microbial diversity of Nicotiana tabacum rhizosphere microbiomes using ITS rDNA sequencing under different conditions. Compared with soil associated with healthy Nicotiana tabacum , the alpha and beta diversity of the eukaryotic microbial community decreased in soil with diseased Nicotiana tabacum , indicating a decline in microbial abundance and composition. Compared with healthy soil, the eukaryotic microbial community in diseased soil exhibited looser structural networks, with the assembly process of both communities predominantly governed by stochastic processes. Soil element measurements and correlation analyses identified pH, manganese, and copper as key environmental factors associated with the health status of Nicotiana tabacum. A machine learning model incorporating environmental factors and major microbial phyla was developed to predict Nicotiana tabacum health status, achieving a high accuracy of 93%. These findings collectively offer comprehensive insights into the relationship between Nicotiana tabacum health status, soil conditions, environmental factors, and eukaryotic microbial community.

Currently, in the territory of Kyrgyzstan, 50 storage facilities of obsolete pesticides exist; they store about 5000 tons of these hazardous chemicals. The storage conditions have become unusable for a long time. They pose a serious threat to the people living there, livestock, and the environment. The main purpose of this research was the use of selected bacteria with cytochrome P450 genes for the bioremediation of polluted soils around the burial sites in model soil experiments. In the first trial of biodegradation experiments, one contaminated soil was used without any changes in chemical contents, and in the second, the physical and chemical contents of the soil were improved to maintain the bioremediation conditions. The soils in both variants were treated 3 times (ie, once a month) with suspensions of a single culture or a blend of active bacteria (1 × 108 cells/mL) selected from in vitro biodegradation experiments. Two control units without the addition of the bacteria culture were also run. The quantification of targeted persistent organic pollutants (POPs) before and after biodegradation was performed by capillary gas chromatography (GC) coupled to a mass spectrometer. In 6 months, obsolete pesticides such as dieldrin, α-endosulfan, β-endosulfan, and 4-heptachlor-epox pure were able to degrade almost completely, up to 98% to 99.0%, by the blend of bacteria and the single culture of bacteria. Endrin aldehyde showed more resistance as the blend of bacteria was able to degrade it to 59.77%. To improve the aerobic degradation for elimination of pesticides from contaminated soils, it is necessary to create optimal agrotechnical and agrochemical conditions.

Six sunflower herbicides were tested at two application rates (1N and 2N) on three locations (with different soil types) within three years (2015–2017). Efficacy of the tested herbicides on Chenopodium album increased with an increasing cation exchange capacity (CEC) of the soil. Efficacy of pendimethalin was 95%, flurochloridone and aclonifen 94%, dimethenamid-P 72%, pethoxamid 49% and S-metolachlor 47%. All tested herbicides injured sunflower on sandy soil (Regosol) which had the lowest CEC, especially in wet conditions (phytotoxicity 27% after 1N application rate). The highest phytotoxicity was recorded after the application of dimethenamid-P (19% at 1N and 45% at 2N application rate). Main symptoms of phytotoxicity were leaf deformations and necroses and the damage of growing tips, which led to destruction of some plants. Aclonifen, pethoxamid and S-metolachlor at 1N did not injure sunflower on the soil with the highest CEC (Chernozem) in any of the experimental years. Persistence of tested herbicides was significantly longer in Fluvisol (medium CEC) compared to Regosol and Chernozem. Dimethenamid-P showed the shortest persistence in Regosol and Chernozem. The majority of herbicides was detected in the soil layer 0–5 cm in all tested soils. Vertical transport of herbicides in soil was affected by the herbicide used, soil type and weather conditions. The highest vertical transport was recorded for dimethenamid-P and pethoxamid (4, resp. 6% of applied rate) in Regosol in the growing season with high precipitation.

Aims Arbuscular mycorrhizal fungi (AMF) could influence plant abilities of total nitrogen (N) acquisition. Global changes have been influencing availabilities of different N forms and water resources in soil. However, it is uncertain whether and how AMF colonization affects plant uptake and preference of different N forms and how are they affected by soil water conditions. Methods We conducted a pot experiment with Funneliformis mosseae (a common arbuscular mycorrhizal fungal species) colonized and non-colonized maize ( Zea mays L.) growing at low and high water conditions, the growth medium contained much more nitrate (NO 3 − ) than ammonium (NH 4 + ). Results F. mosseae colonization and high water availability increased maize biomass and total N uptake. Enhanced water supply increased proportional contributions of NH 4 + to colonized and non-colonized maize because high water conditions may increase NH 4 + accessibility to maize. F. mosseae colonization weakened proportional contributions and preference of NH 4 + in maize, indicating that AMF enable plants to prefer using the more abundant N form and develop more beneficial N uptake strategies considering that NO 3 − was more dominant than NH 4 + in growth medium. Furthermore, maize NH 4 + preference was decreased by F. mosseae colonization more under high than low water conditions. This demonstrated greater effects of AMF on regulating plant N uptake strategies in soils with greater water availability. Conclusions This work revealed the regulation of AMF colonization on plant N uptake strategies under different soil water conditions. The findings enriched our knowledge of plant N use in the context of global changes.

Seismic responses of Nuclear Island (NI) structures have great significance in the foundation adaptability analysis and the seismic design of equipment. However, with the increasing complexity of nuclear power site conditions, establishing a reasonable and effective soil–pile–structure dynamic interaction model has become the key technical problem that needs to be solved. In this study, a pseudo three-dimensional soil–pile–structure dynamic interaction model considering soil nonlinearity and heterogeneity is developed for seismic response analysis of NI structures. Specifically, the nonlinearity of the near-field soil is described via the equivalent linear method, the radiation damping effect of half space is simulated through viscous boundary, and the displacement/stress conditions at lateral boundaries of the heterogeneous site are derived from free-field response analysis. Meanwhile, an equivalent stiffness–mass principle is established to simplify NI superstructures, while pile group effects are incorporated via a node-coupling scheme within the finite-element framework. Two validation examples are presented to demonstrate the accuracy and efficiency of the proposed model. Finally, seismic response analysis of two typical NI structure of reactor types (CPR1000 and AP1000) based on the actual complex site conditions in China is also presented to study the effect of radiation damping, soil conditions, and pile foundation. Key findings demonstrate the necessity of integrating SSI effects and nonlinear characteristics of non-rock foundations. While the rock-socketed pile exhibits superior performance compared to the CFG pile alternative; this advantage is offset by higher costs and construction complexity. The research findings can serve as a valuable reference for the foundation adaptability analysis and optimizing the design of equipment under the similar complex condition of the soil site.

The ecotoxic effect of Zn species arising from the weathering of the marmatite-like sphalerite ((Fe, Zn)S) in Allium cepa systems was herein evaluated in calcareous soils and connected with its sulfide oxidation mechanism to determine the chemical speciation responsible of this outcome. Mineralogical analyses (X-ray diffraction patterns, Raman spectroscopy, scanning electron microscopy and atomic force microscopy), chemical study of leachates (total Fe, Zn, Cd, oxidation–reduction potential, pH, sulfates and total alkalinity) and electrochemical assessments (chronoamperometry, chronopotentiometry, cyclic voltammetry, and electrochemical impedance spectroscopy) were carried out using (Fe, Zn)S samples to elucidate interfacial mechanisms simulating calcareous soil conditions. Results indicate the formation of polysulfides (S n 2− ), elemental sulfur (S 0 ), siderite (FeCO 3 )-like, hematite (Fe 2 O 3 )-like with sorbed CO 3 2− species, gunningite (ZnSO 4 ·H 2 O)-like phase and smithsonite (ZnCO 3 )-like compounds in altered surface under calcareous conditions. However, the generation of gunningite (ZnSO 4 ·H 2 O)-like phase was predominant bulk-solution system. Quantification of damage rates ranges from 75 to 90% of bulb cells under non-carbonated conditions after 15–30 days, while 50–75% of damage level is determined under neutral-alkaline carbonated conditions. Damage ratios are 70.08 and 30.26 at the highest level, respectively. These findings revealed lower ecotoxic damage due to ZnCO 3 -like precipitation, indicating the effect of carbonates on Zn compounds during vegetable up-taking (exposure). Other environmental suggestions of the (Fe, Zn)S weathering and ecotoxic effects under calcareous soil conditions are discussed.