Moisture Regimes Research Articles

Adequate water supply enhances seedling growth and metabolism in Festuca kryloviana: insights from physiological and transcriptomic analys

BackgroundFestuca kryloviana is a significant native grass species in the Qinghai Lake region, and its low emergence rate is a primary factor limiting the successful establishment of cultivated grasslands. The region’s arid and low-rainfall climate characteristics result in reduced soil moisture content at the surface. Despite the recognized impact of water availability on plant growth, the specific role of moisture in seedling development remains not fully elucidated. This study aims to investigate the germination rate and seedling growth velocity of F. kryloviana seeds under varying moisture conditions, and to integrate physiological and transcriptomic analyses of seedlings under these conditions to reveal the mechanisms by which water influences seedling development.ResultsThe emergence rate of F. kryloviana seedlings exhibited an initial increase followed by a decrease with increasing moisture content. The highest emergence rate, reaching 75%, was observed under 20% soil moisture conditions. By the eighth day of the experiment, the lengths of the plumules and radicles under the optimal emergence rate (full water, FW) were 21.82% and 10.87% longer, respectively, than those under closely matching the soil moisture content during the background survey (stress water, SW). The differential development of seedlings under varying moisture regimes is attributed to sugar metabolism within the seeds and the accumulation of abscisic acid (ABA). At FW conditions, enhanced sugar metabolism, which generates more energy for seedling development, is facilitated by higher activities of α-amylase, sucrose synthase, and trehalose-6-phosphate synthase compared to SW conditions. This is reflected at the transcriptomic level with upregulated expression of the α-amylase (AMY2) gene and trehalose-6-phosphate synthase (TPS6), while genes associated with ABA signaling and transduction are downregulated. Additionally, under FW conditions, the expression of genes related to the chloroplast thylakoid photosystems, such as photosystem II (PSII) and photosystem I (PSI), is upregulated, enhancing the seedlings’ light-capturing ability and photosynthetic efficiency, thereby improving their autotrophic capacity. Furthermore, FW treatment enhances the expression of the non-enzymatic antioxidant system, promoting metabolism within the seeds. In contrast, SW treatment increases the activity of the enzymatic antioxidant system, including peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT), to cope with water stress.ConclusionsOur experiment systematically evaluated the impact of moisture conditions on the growth and development of F. kryloviana seedlings. Physiological and transcriptomic data collectively indicate that adequate water (20%) supply enhances seedling growth and development by reducing ABA levels and increasing α-amylase activity within seeds, thereby boosting sugar metabolism and promoting the growth of seedling, which in turn leads to an improved emergence rate. Considering water management in future cultivation practices may be a crucial strategy for enhancing the successful establishment of F. kryloviana in grassland ecosystems.

Wood decay and Norway spruce vulnerability to wind-inflicted mortality in monospecific and mixed stands in hemiboreal forests

Pathogen-caused stem and root decay are becoming increasingly common in Norway spruce (Picea abies (L.) H. Karst) which is believed to contribute to greater stand instability and susceptibility to wind-inflicted damage. Thus, this study aims to assess the effect of root and stem decay on Norway spruce vulnerability to wind-inflicted mortality in monospecific and mixed stands, to widen our base of knowledge on potentially more resilient spruce forest management approaches in hemiboreal forest zone. In this study we used data from: i) the National Forest inventory (NFI), ii) 34 observation plots established in wind-affected stands, iii) two transects (9200 m long, 36.8 ha inspection area combined), iv) and monospecific spruce plantation thinning experiment (five thinning intensities with two repetitions of each) affected by wind. We found that the total mortality of spruce during the NFI four five-year re-measurement cycles (2003–2007, 2008–2012, 2013–2017, 2018–2022) was 2.28 %, during which the main disturbance-causing agents were wind at 0.86 %, pests at 0.41 %, intra/interspecific competition at 0.37 %, and diseases at 0.36 %. NFI data-based multinomial logistic regression model revealed that the probability of wind-inflicted spruce mortality is dictated by soil moisture regime, stand age, stand stocking level, and tree decay presence. Results from the 34 established observation plots show that wood decay is a potential risk factor associated with wind damage occurrence in spruce stands. In a spruce stand, when a group of trees are damaged by wind the proportion of undecayed trees increases. Whereas a single tree is more likely to be attributed to decay caused wind damage.Results point towards deciduous broadleaf admixture having a positive effect on mitigating wind damage among non-decayed spruce trees: however, decayed trees, are more likely to be affected in such stands. The thinning experiment portion of this study suggests that increasingly intensive thinning in monospecific spruce stands will lead to an increasing spread of root and stem decay and thus the risk of wind damage. Therefore, from this perspective, the main goal is to reduce the root and stem decay presence in the stand and thus increase wind stability. We suggest further research to be directed into finding the optimal initial spruce seedlings density with a combination of coniferous and deciduous broadleaf species in order to mitigate root and stem decay presence and wind-inflicted spruce mortality in the forest stands.

Land-Use Feedback under Global Warming—A Transition from Radiative to Hydrological Feedback Regime

Abstract This study examines the effects of land-use (LU) change on regional climate, comparing historical and future scenarios using seven climate models from phase 6 of Coupled Model Intercomparison Project–Land Use Model Intercomparison Project experiments. LU changes are evaluated relative to land-use conditions during the preindustrial climate. Using the Community Earth System Model, version 2–Large Ensemble (CESM2-LE) experiment, we distinguish LU impacts from natural climate variability. We assess LU impact locally by comparing the impacts of climate change in neighboring areas with and without LU changes. Further, we conduct CESM2 experiments with and without LU changes to investigate LU-related climate processes. A multimodel analysis reveals a shift in LU-induced climate impacts, from cooling in the past to warming in the future climate across midlatitude regions. For instance, in North America, LU’s effect on air temperature changes from −0.24° ± 0.18°C historically to 0.62° ± 0.27°C in the future during the boreal summer. The CESM2-LE shows a decrease in LU-driven cooling from −0.92° ± 0.09°C in the past to −0.09° ± 0.09°C in future boreal summers in North America. A hydroclimatic perspective linking LU and climate feedback indicates LU changes causing soil moisture drying in the midlatitude regions. This contrasts with hydrology-only views showing wetter soil conditions due to LU changes. Furthermore, global warming causes widespread drying of soil moisture across various regions. Midlatitude regions shift from a historically wet regime to a water-limited transitional regime in the future climate. This results in reduced evapotranspiration, weakening LU-driven cooling in future climate projections. A strong linear relationship exists between soil moisture and evaporative fraction in midlatitudes. Significance Statement Land–atmosphere feedback involving soil moisture can increase local temperature and affect how land-use (LU) change impacts manifest in a warming climate. Conversely, an increased surface reflectance due to LU change can decrease local temperature in the midlatitude regions. Further, the LU change signal is often mixed with the internal climate variability, making it harder to separate. This study uses a novel technique to separate LU change impact from other climate forcing in the latest generation of climate and Earth system models. In the future climate, soil moisture drying lessens the cooling impact. A large-ensemble climate experiment analysis confirms a significant weakening of the LU-driven cooling impact in the midlatitudes. Both LU and climate changes exacerbate soil moisture drying, leading to a shift toward a water-limited system where hydrological feedback becomes more influential than radiative feedback.

Ecological characteristics of biotopes and the structure of communities with <i>Globularia</i> L. (Plantaginaceae, Magnoliopsida) within the Eastern European fragment of its range

The paper presents an assessment of the ranges of ecological conditions in which Globularia bisnagarica L. and G. trichosantha Fisch. & С. A. Mey species exist in communities growing in European Russia. Studies were carried out in 25 communities with G. bisnagarica and 4 ones with G. trichosantha, respectively. Our assessment of the ecological regimes of phytocenoses according to D. N. Tsyganov’s scales has shown that both species live in very narrow ranges of climatic, soil factors and lighting, being stenovalent. For G. bisnagarica, the thermoclimatic and light factors were the most limiting ones. Few soil characteristics such as salinity and nitrogen richness were the limiting factors for G. trichosantha. According to the spectrum of ecomorphs, the communities of the two species were similar. The vast majority of species are classified as steppe ones. Hemicryptophytes were the predominant type of biomorphs. In relation to trophicity, more than half of the species was mesotrophic. According to the temperature regime, the meso- therms were the predominant group. The range of moisture regimes in the habitats of communities contributes to the growth of xerophytes and meso-xerophyte species to a greater extent. Due to certain specificity of the habitats of communities with Globularia on open slopes, most species were heliophytes. Our analysis of regularities of changes in the species composition of the com- munities in relation to environmental factors at global scale has shown that temperature factors make the greatest contribution.

Assessment of environmental impact of road construction based on results of remote sensing monitoring

Remote sensing detected the impact of road construction on important environmental properties. The digital elevation model was applied to assess the impact of road construction on environmental regimes. The study focused on the total area of the 3-km zone of influence (monitoring zone of probable impact) around the national road H-31 Dnipro-Tsarychanka-Kobeliaky-Reshetylivka from Loboikivka village to the boundary of Dnipropetrovsk Oblast. The following derivatives of the digital elevation model are considered as geomorpho­logical variables: the topographic wetness index (TWI) and erosion factor (LS). To model the effect of road construction on the moisture regime and dynamics of erosion processes, the TWI and LS indices were calculated for a digital terrain model without a road and with a road with an elevation that corresponds to the planned level. Thus, the road is considered as an anthropogenic landform that changes the direction of water redistribution along the topography and thus affects the potential moisture conditions and erosion risks. The modeling results indicate that the transformation of the water regime will be observed within the entire 3-km monitoring area. Deviations from the normal value can be up to 7 units by module, which is about one third of the landscape-wide range of topographic moisture index values. Almost no impact of construction can be predicted for 80.7% of the territory. For 10.6% of the territory, the increase in moisture regime will be moderate, and for 3.2% of the area the increase will be very significant. In turn, for 4.3% of the area the decrease in humidification will be moderate, and for 1.2% the decrease will be very significant. The greatest impact on the redistribution of moisture conditions is predicted in the immediate vicinity of the road. Changes in the moisture regime can have significant negative consequences for both soil cover and biotic components of ecosystems. Changes in vegetation as a consequence of changes in both moisture and trophic conditions can be considered as possible scenarios for the development of landscape cover dynamics.

Influence of biochemical composition of above-ground biomass of oilseed radish on the expediency of its green manure application

Over a ten-year period, the volumes of formed ground biomass of oil radish and its biochemical composition were estimated for spring and summer plantings in terms of its green manure application. The formed leaf and stem mass of the oil radish variety Zhuravka was studied using official AOAC international analysis methods, liquid chromatography, methods of field evaluation of yield and weight and equivalent indicators. The effectiveness of green manure application was assessed by the method of multicriteria-decision support. Oil radish was confirmed to have a high adaptive potential at the maximum level of determination of bioproductivity, with an optimal moisture and temperature supply of up to 40%. The long-term average productive and biochemical portfolio of oil radish was identified as follows: 21.19 t/ha of leaf-stem ground mass with 62.3% soil cover 70 days after sowing, 2.8% nitrogen, 22.8% fibre, 0.6% phosphorus, 3.8% potassium, 16.6 μmol/g glucosinolates at the C/N ratio of 14.7, 83% plant-mass quality, and 48.1 mol/ha biofumigation potential based on glucosinolate aucumulation. The study confirmed the high potential of oilseed-radish adaptability to the regimes of unstable moisture of territories, finding interannual variation of the total bioproductivity and biochemical parameters of leaf-mass quality with the value of the variation coefficient ranging 23.6–31.2%, depending on the sowing date. The effectiveness of oilseed radish was also revealed by comparison with the similar interannual variation of hydrothermal conditions of vegetation (the amount of precipitation 48.2%, average daily temperature 27.5%, moisture coefficient 68.1%, and aridity index 58.9%). Oilseed radish was found to be agrobiologically and agrotechnologically feasibile to be used in the system of both spring and summer (intermediate) green manure technologies in grey loess soils under conditions of unstable moisture, as indicated by its bioproductivity and biochemical quality of leaf mass, as well as the results of the components of the multicriteria assessment of the plant as green manure, the value of normalised weight coefficients ranging 0.62–0.99

Irrigation scheduling for high value vegetable crops grown under protected cultivation in the hilly ecosystem of north-east India

Irrigation scheduling plays a vital role in the efficient utilization of water to obtain optimum yield, particularly for high value crops grown under protected conditions. The present experiment was conducted during 2020–22 at Horticulture Experimental Farm, ICAR-Research Complex for North Eastern Hill Region, Umiam, Meghalaya to standardize the irrigation scheduling (IS) (5, 7, and 10-days interval) in high-value vegetable crops [tomato (Solanum lycopersicum L.), capsicum (Capsicum annuum L.) and king-chilli (Capsicum chinense Jacq.)] grown under naturally ventilated low-cost polyhouse in the mid-hill conditions of Meghalaya. The results revealed a significant effect of IS on plant growth (reduction in plant height, leaf area) and yield attributes (fruit setting, fruit size, fruit weight and total yield) of the crops with an increase in level of moisture stress. The highest yield of tomato (82.7 t/ha), capsicum (40.8 t/ha) and king-chilli (11.8 t/ha) was recorded in the 5-day interval of IS and on increasing the IS interval to 7-days, the yield decreased by 28.7, 36.1 and 35.7%, respectively. Among the crops, capsicum was found to be more sensitive to water stress, followed by king-chilli and tomato. Among the crops, water productivity with respect to irrigation water was maximum in tomato (60.0 g/kg) followed by capsicum (17.2 g/kg) and king-chilli (10.0 g/kg). Among the varieties grown, Megha Tomato-3 of tomato, hybrid Mahabharat of capsicum and landrace Red Long of king-chilli were found superior for growth and yield attributes at different levels of moisture regime. The farmers of the region can get higher yield using identified varieties with irrigation at 5-days intervals.

Interactive effects of fungal community structure and soil moisture on Wyoming big sagebrush performance

Abstract Aims Local adaptation of plant populations to soil biotic conditions may complicate ecosystem restoration if seeds used in reseeding efforts are sourced from a different population than the one that succumbed to disturbance. Furthermore, climatic conditions may mediate the interaction between plants and soil microbial communities. This study aimed to assess how the composition of the local soil fungal community affects Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis) growth and its resource allocation to shoot and root growth under different moisture-availability conditions. Methods We explored sagebrush growth responses to inoculation with wet-adapted versus dry-adapted sagebrush-associated fungal communities in a 7-month greenhouse experiment. Seeds were planted with inoculum isolated from rhizosphere soil from either a relatively wet or a dry sagebrush-dominated site and subjected to a moisture regime representative of either the wet or dry site. Biomass, root morphology, and fungal community composition were assessed. Results Wet and dry sites hosted distinct in-situ fungal communities, and inoculum derived from different sites generated compositionally different fungal assemblages in the seedlings’ rhizospheres during the growth period. Compared to sterilized inoculum controls, live inoculum from either site enhanced seedling biomass, but only when soil moisture simulated that of the inoculum’s source site. Dry-site inoculum also produced longer, finer roots under dry-site conditions. Conclusions Moisture similar to the fungal inoculum’s source was necessary for fungi to positively impact sagebrush growth and root characteristics. Applying fungal inoculum adapted to an intended restoration site’s moisture could help seedlings optimize water uptake and productivity, encouraging sagebrush establishment.

Effect of Long Term Tillage and Soil Moisture Regime on the Chemical Properties of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

Effect of Long Term Tillage and Soil Moisture Regime on the Chemical Properties of Soil under Mung Bean-Wheat and Sorghum-Wheat Cropping System

ЭКОЛОГО-ЦЕНОТИЧЕСКАЯ И БИОЛОГИЧЕСКАЯ ХАРАКТЕРИСТИКА SALVIA TESQUICOLA KLOKOV & POBED НА ТЕРРИТОРИИ ПРАВОБЕРЕЖЬЯ САРАТОВСКОЙ ОБЛАСТИ

The article presents the results of research on Salvia tesquicola Klokov & Pobed as a promising medicinal plant. The study was conducted during the growing seasons 2020-2023. on the territory of the right bank of the Saratov region. In the communities with the participation of steppe sage, 119 species of higher flowering plants belonging to 28 families were noted. The leading place in the number of species is occupied by the family Asteraceae (25.6 %). Comparison of phytocenoses using the Jaccard coefficient showed a high degree of heterogeneity in their species composition. Among the coenomorphs, the most numerous are ruderants (45% of the number of species of the studied flora) and stepants (35 %), hygromorphs - xeromesophytes (49 %), trophomorphs - mesotrophs (58 %). On the territory of the Saratov region, S. tesquicola is characterized by habitats with moderately fertile soils and a dryish-fresh moisture regime. This species prefers anthropogenically disturbed areas, where an increase in its phytomass is observed. The yield value was 183.6±0.04 g/m2. Aqueous extracts from the above-ground organs of S. tesquicola have allelopathic activity and negatively affect the germination of seeds of dicotyledonous plants and the development of monocotyledonous seedlings. When comparatively assessing the data obtained by the spectrophotometric method, it was found that elements such as Cd and Cu exceed the normal concentration. At all sampling points, an excess of the toxic concentration of Cr is also observed, since S. tesquicola is an active accumulator of this element. This type of plant is often used in folk medicine but due to the revealed data on the accumulation of some heavy metals, it is necessary to carefully select the place where raw materials are collected.

Impact of soil moisture regimes on greenhouse gas emissions, soil microbial biomass, and enzymatic activity in long-term fertilized paddy soil

Two potent greenhouse gases that are mostly found in agricultural soils are methane and nitrous oxide. Therefore, we investigated the effect of different moisture regimes on microbial stoichiometry, enzymatic activity, and greenhouse gas emissions in long-term paddy soils. The treatments included a control (CK; no addition), chemical fertilizer (NPK), and NPK + cattle manure (NPKM) and two moisture regimes such as 60% water-filled pore spaces (WFPS) and flooding. The results revealed that 60% water-filled pore spaces (WFPS) emit higher amounts of N2O than flooded soil, while in the case of CH4 the flooded soil emits more CH4 emission compared to 60% WFPS. At 60% WFPS higher N2O flux values were recorded for control, NPK, and NPKM which are 2.3, 3.1, and 3.5 µg kg−1, respectively. In flooded soil, the CH4 flux emission was higher, and the NPKM treatment recorded the maximum CH4 emissions (3.8 µg kg−1) followed by NPK (3.2 µg kg−1) and CK (1.7 µg kg−1). The dissolved organic carbon (DOC) was increased by 15–27% under all flooded treatments as compared to 60% WPFS treatments. The microbial biomass carbon, nitrogen, and phosphorus (MBC, MBN, and MBP) significantly increased in the flooded treatments by 8–12%, 14–21%, and 4–22%, respectively when compared to 60% WFPS. The urease enzyme was influenced by moisture conditions, and significantly increased by 42–54% in flooded soil compared with 60% WFPS while having little effect on the β-glucosidase (BG) and acid phosphatase (AcP) enzymes. Moreover DOC, MBC, and pH showed a significant positive relationship with cumulative CH4, while DOC showed a significant relationship with cumulative N2O. In the random forest model, soil moisture, MBC, DOC, pH, and enzymatic activities were the most important factors for GHG emissions. The PLS-PM analysis showed that soil properties and enzymes possessed significantly directly impacted on CH4 and N2O emissions, while SMB had indirect positive effect on CH4 and N2O emissions.

Advancements in Soil Organic Carbon Mapping and Interpolation Techniques: A Case Study from Lithuania’s Moraine Plains

Monitoring soil organic carbon (SOC) is essential for assessing the sustainability of soil usage. This study explores the spatial variability and mapping of SOC in Lithuania’s Nevėžis Plain using various interpolation methods, with an emphasis on understanding the impacts of soil typological units, moisture regimes, and erosion on SOC distribution. A total of 275 soil samples were collected from agricultural croplands at depths of 0–10 cm, supplemented by 38 samples from previous studies. The SOC map was created based on the contours of the Lithuanian soil geodatabase. Statistical analysis revealed that the distribution of SOC in the studied area was significantly influenced by soil moisture and the degree of erosion. Based on these findings, SOC mapping was conducted according to the contours of Lithuanian soils. Comparing the interpolation methods that were analyzed, it was found that the kriging, RBF, and EBK methods fail to adequately capture the minimum and maximum values of SOC, while the IDW fails to adequately capture only the minimum values. In summary, the integrated geographical approach is complex but applicable to SOC mapping. This method facilitates the creation of adaptable SOC maps that are both geographically and pedologically informed. Key principles to apply this approach for future research and practical application should include establishing a statistically reliable data foundation, categorizing samples based on contrasting soil moisture regime, degrees of erosion, and land use patterns, and developing contouring principles along with a criteria algorithm that enables accurate spatial interpolation of average SOC values.

Organic carbon in Mollisols of the world − A review

Mollisols represent 29 % of agricultural land and they are considered to be one of the most fertile soils in the world. Here, we compare soil organic carbon (SOC) concentrations and pools of Mollisols for the globe, the USA and Poland, and review how differences are caused by climate, land use, and key environmental factors. Globally, the mean thickness of the A horizon in Mollisols is 50 cm. At 0–30 cm the mean SOC concentration is 2.3 %, SOC pool is 84 t ha−1, and clay content calculated at 0–50 cm soil depth is 21 %. Mollisols in the USA have an A horizon thickness of 36 cm and have a mean clay content of 27 % (0–50 cm). SOC concentrations are 2.0 and 1.7 % and SOC pools are 85 and 116 t ha−1 at 0–30 and 0–50 cm soil depth, respectively. Mollisols in Poland have SOC concentrations of 1.8 and 1.5 % at 0–30 and 0–50 cm soil depth, respectively, and lower clay content (17 %) at 0–50 cm depth. The SOC pool at 0–30 cm depth is 74 t ha−1 whereas it is 106 t ha−1 at 0–50 cm. At the global scale, the highest SOC concentrations and pools are in Mollisols from Eastern Europe (including Ukraine and Western Russia) and Asia, while the lowest SOC pools are found in Mollisols from South America. The Mollisols in Western and Central Europe and North America have similar SOC pools, although Mollisols in North America have higher SOC concentrations and lower A horizon thickness. Globally, the mean pH value of Mollisols is 7.1, and the pH is slightly lower in Mollisols of the USA (6.9 ± 0.9). The SOC concentrations and pools are strongly and positively correlated with clay content. Soil moisture and temperature regimes determine SOC concentration and pools in Mollisols, and higher SOC concentrations and pools are in Mollisols with frigid and frigid-cryic soil temperature regimes as well as aquic, xeric, and aridic soil moisture regimes. Mollisols under grassland have the largest SOC pools compared to those cultivated or under forest. The important environmental factors on SOC concentrations and pools in Mollisols worldwide are soil texture, land use, and soil temperature regime.

Performance of ACCase-Resistant and ACCase-Susceptible Phenotypes of Sterile Oat Avena sterilis subsp. ludoviciana (Durieu) Nyman under Drought Conditions in the Greenhouse

Climate change might benefit water-stress-adapted weeds, further impairing their management. To evaluate the impact of soil moisture regimes on the growth and reproductive behaviour of ACCase-resistant and ACCase-susceptible phenotypes of sterile oat (Avena sterilis subsp. ludoviciana (Durieu) Nyman), a greenhouse experiment was carried out in 2020 and 2021. The factors were soil moisture regimes (100% field capacity (FC) as well-watered, 75% FC, 50% FC, and 25% FC) and ACCase-resistant and ACCase-susceptible phenotypes of sterile oat. Increased drought stress conditions reduced the number of tillers per plant by 34, 55, and 83% and the number of seeds per plant by 36, 61, and 89% in the 75% FC, 50% FC, and 25% FC conditions, respectively, compared to the well-watered treatment. Notably, both phenotypes reacted similarly to water stress, with no interactions between the two factors. Regardless of water stress, the resistant phenotypes produced fewer seeds per plant, indicating fitness costs. However, due to their high plasticity, both phenotypes will still produce seeds even when facing severe water stress conditions. Thus, sterile oat is expected to continue infesting crop fields in the near future, but with ACCase-resistant phenotypes being less successful than susceptible ones in the absence of herbicide application.

Pore unit cell network modeling of the thermal conductivity dynamics in unsaturated sandy soils: Unveiling the role of spanning‐wetting phase cluster

AbstractAs the world struggles with climate change and energy crises, understanding the role of soil in the food–water–energy nexus becomes increasingly critical. Accurately estimating the soil thermal conductivity drying curve is essential for assessing the impacts of temperature on soil biota and crop growth, environmental changes due to forest fires and global warming, and for designing geo‐energy extraction techniques such as geothermal energy piles. Existing empirical models often fail to accurately estimate the soil thermal conductivity (TC), particularly in pendular soil moisture regimes where they do not capture sharp changes in TC. This study introduces a novel approach using a pore unit cell network model to more accurately describe the dynamics of TC in variably saturated soils. A quadratic parallel scheme within each soil pore unit cell links the TCs of solid, water, and air to the overall effective conductivity. By modeling air invasion in the pore network model and employing the proposed equation, we determined the unsaturated soil TC based on varying local conductivities. The model effectively captures the significant decrease in conductivity in the pendular saturation regime, associated with the shrinkage of the spanning‐wetting cluster. Quantitative analyses showed a substantial improvement in prediction accuracy compared to existing models, especially under varying moisture conditions. Our findings have significant implications for better characterizing soil thermal and hydraulic properties, which are crucial for resource management in a changing climate and advancing geo‐energy technologies.

Severe Wildfire Affects the Thermal and Moisture Regimes of At-Risk Turtle Nesting Habitat

Severe Wildfire Affects the Thermal and Moisture Regimes of At-Risk Turtle Nesting Habitat

Peculiar wetting behavior of nanodroplets comprising antagonistic alcohol-water mixtures on a graphene surface

Binary mixtures, consisting of partially and totally wetting liquids with respect to a specific substrate and known as an antagonistic mixture, are commonly encountered. Although the wetting behavior of antagonistic mixtures deviates from that of conventional liquids, studies exploring this phenomenon are scarce. At the nanoscale, the wetting behavior of nanodroplets containing such mixtures may diverge even further from our established understanding. Employing Nanoscale Molecular Dynamics simulations, we explore the wetting behavior of nanodroplets containing mixtures of water (partial wetting) and ethanol or isopropanol (total wetting) on a graphene surface. By adjusting the water fraction (xw) in the antagonistic mixture, three distinct wetting states have been identified: (I) In total wetting regime (low xw), spontaneous spreading is observed; (II) In plateau regime (medium xw), alcohol leakage from the droplet occurs, with the apparent contact angle (CA) remaining constant; (III) In partial wetting regime (high xw), the CA increases with xw and alcohol molecules tend to accumulate at the contact line. Unexpectedly, the spreading coefficient (S) remains positive and turns negative only as xw near unity. Furthermore, Young's equation proves to be inapplicable even when S < 0. These peculiar wetting phenomena are comprehensively discussed and elucidated.

Effect of Land Configuration Technique and Moisture Regime on Water Productivity of Maize (Zea mays L.) in Summer Season

Effect of Land Configuration Technique and Moisture Regime on Water Productivity of Maize (Zea mays L.) in Summer Season

Evaluation of Soil Quality of Pingliang City Based on Fuzzy Mathematics and Cluster Analysis

Pingliang City has a complex topography and diverse soil types. To realize the improvement of soil according to local conditions and the reasonable and sustainable use of soil resources, an evaluation of soil quality in Pingliang City was carried out, based on the soil distribution situation in Pingliang City, adopting a method combining fuzzy mathematics and cluster analysis of the main evaluation factors, such as soil organic matter, topsoil depth, soil erosion intensity, soil moisture regime, effective soil thickness, soil texture, soil profile structure, soil nutrient status and topographical parts, to carry out a comprehensive evaluation. A comprehensive evaluation of soil quality was conducted in seven counties under the jurisdiction of Pingliang City, and the evaluation results were compared and analyzed against the national standard, “Cultivated land quality grade”, to provide a basis for the selection of scientific soil improvement methods. The results of the arable land quality grades indicate that the quality of farmland in Pingliang City is divided into three to ten grades, and the average quality grade of farmland is 6.83, which is in the middle–lower level, and the overall grade distribution shows the characteristics of low in the middle and high in the east and west. The results of fuzzy mathematics combined with cluster analysis indicated the following trends in soil quality for the 12 soil genera: Chuan black gunny soil &gt; yellow moist soil &gt; sandy soil &gt; silt soil &gt; mulching helilu soil&gt; loessal soil&gt; loamy soil &gt; slope loessal soil &gt; arenosol &gt; tillage leaching gray cinnamon soil &gt; calcareous gray cinnamon soil &gt; red clay soil. The results of the combination of fuzzy mathematics and clustering were significantly correlated with the results of the evaluation of the soil quality of arable land; the correlation coefficient was 0.884. This indicates that the method can accurately and objectively review the advantages and disadvantages of arable land soil and can be effectively applied to the evaluation of the soil quality of agricultural soils in other regions. It is a complement to the existing evaluation of the soil quality of arable land and at the same time provides a reference for the improvement of soil quality in agricultural regions.

Application of the Moisture Potential Theory in Assessing the Heat and Moisture Regime of Building Envelopes

Application of the Moisture Potential Theory in Assessing the Heat and Moisture Regime of Building Envelopes