Dry Cycles Research Articles

Surface Treatment of Oak Wood with Silica Dioxide Nanoparticles and Paraloid B72

Wood is a valuable material with incomparable advantages, though it is susceptible to biotic and abiotic factors action that affect it adversely and shorten its service life. In the current study, the surface modification of oak wood is carried out through brief immersion in a solution of acrylic polymer Paraloid B72, in which silica dioxide nanoparticles in the form of nanopowder were dissolved at different contents (1, 2, 3, and 4% w/v of the solution) aiming at the elimination of wood material hygroscopicity, and the protection and improvement of other properties. Specifically, the modified and unmodified wood specimens were characterized in terms of physical characteristics (density, equilibrium moisture content, colour, and surface roughness), hygroscopic properties (swelling and absorption percentage) and accelerated weathering performance using xenon light and cycles of moisturizing and drying. The results revealed the dimensional stability of the samples and a significant increase in the hydrophobicity of the modified wood, as well as a significant increase in the resistance to the ageing/weathering factors of oak wood, which was proportional to the increase in the presence of nanoparticles in the Paraloid B72 solution. The colour of the treated samples slightly changed towards darker shades, more reddish and yellowish (with L* to decrease, while a* and b* to slightly increase), though the treated wood revealed higher colour stability. The surface roughness parameters (Ra, Rq, and Rz) increased significantly, restricting the wide application of the treated wood in indoor or outdoor applications where surface roughness constitutes a critical factor. The findings of the current work contribute not only to the production of longer-lasting wood and timber structures, but also to the conservation of the existing weathered heritage timber structures.

Enhancing Compressive Strength of Cement by Indigenous Individual and Co-Culture Bacillus Bacteria

Using a Taguchi experimental design, this research focuses on utilizing indigenous bacteria from the Danube River to enhance the self-healing capabilities and structural integrity of cementitious materials. Bacillus licheniformis and Bacillus muralis were used as individual bacterium or in co-culture, with a concentration of 8 logs CFU, while the humidity variation involved testing wet and wet–dry conditions. Additionally, artificial neural network (ANN) modeling of the compressive strength of cement samples results in improvements in compressive strength, particularly under wet–dry conditions. By inducing targeted bacterial activity, the formation of calcium carbonate precipitates was initiated, which effectively sealed formed cracks, thus restoring and even enhancing the material’s strength. In addition to short-term improvements, this study also evaluates long-term improvements, with compressive strength measured over periods extending to 180 days. The results demonstrate sustained self-healing capabilities and strength improvements under varied environmental conditions, emphasizing the potential for long-term application in real-world infrastructure. This study also explores the role of environmental conditions, such as wet and wet–dry cycles, in optimizing the self-healing process, revealing that cyclic exposure conditions further improve the efficiency of strength recovery. The findings suggest that autochthonous bacterial co-cultures can be a viable solution for enhancing the durability and lifespan of concrete structures. This research provides a foundation for further exploration into bio-based self-healing mechanisms and their practical applications in the concrete industry.

Effect of exogenous application of salicylic acid on alleviation of drought stress of immature tea (Camellia sinensis L.) plants

Abstract Application of salicylic acid (SA) leads to positive impacts in improving the physiological and growth parameters under drought in other crops. Knowledge on SA regulation on tea is scanty but important especially under drought. Therefore, potential of minimizing the drought effects on tea via exogenous application of SA was studied in a glasshouse at the Tea Research Institute, Talawakelle, Sri Lanka, using one-year-old potted tea cultivars of known drought tolerance (TRI 2025 – tolerant and TRI 2023 – susceptible). Plants were exposed to a drying cycle while they were foliar sprayed with SA in various concentrations (0, 50, 100, 150 and 200 ppm) along with well-watered and no-spray treatments. Data were collected at 18 hours and 3, 7, 14 and 21 days after applying the treatments from randomly selected plants. Physiological parameters were measured along with soil moisture content. Drought stress led to declining of gas exchange parameters (rate of net photosynthesis, transpiration and stomatal conductance), leaf relative water content and increasing accumulation of osmolytes (total soluble sugar and proline) in both tea cultivars compared with well-watered plants. Exogenous application of 150 and 200 ppm SA significantly improved physiological parameters. These results revealed the role of exogenous application of 150 and 200 ppm SA in diminishing the negative effects of drought on tea plants. Exogenous application of SA 150 ppm will therefore be more effective in alleviating the drought impact on immature tea when considering the environmental impact and cost effectiveness.

Study on the Effect of Hot and Humid Environmental Factors on the Mechanical Properties of Asphalt Concrete.

To investigate the effect of hot and humid environmental factors on the mechanical properties of asphalt mixtures research, in this paper, the dynamic modulus of asphalt mixtures under the effects of aging, dry-wet cycling, and coupled effects of aging and dry-wet cycling were measured by the simple performance tester (SPT) system, and the dynamic modulus principal curves were fitted based on the sigmoidal function. The results show that under the aging effect, the dynamic modulus of asphalt mixture increases with the aging degree; the dynamic modulus of short-term aged, medium-term aged, long-term aged, and ultra-long-term aged asphalt mixtures increased by 9.3%, 26.4%, 44.8%, and 57%, respectively, compared to unaged asphalt mixtures at 20 °C and 10 Hz; the high-temperature stability performance is enhanced, and the low temperature cracking resistance performance is enhanced; under the dry-wet cycle, the aging effect of asphalt water is more obvious in the early stage, and dynamic modulus of resilience of the mixture is slightly increased. In the long-term wet-dry cycle process, water on the asphalt and aggregate erosion increased, the structural bearing capacity attenuation, and the dynamic modulus of rebound greatly reduced at 20 °C and 10 Hz. For example, the dynamic modulus of asphalt mixtures with seven wet and dry cycles increased by 3% compared to asphalt mixtures without wet and dry cycles, and the dynamic modulus of asphalt mixtures with 14 cycles of wet and dry cycles and 21 cycles of wet and dry cycles decreased by 10.8% and 16.5%, respectively, compared to asphalt mixtures without wet and dry cycles. The main curve as a whole shifted downward; the high-temperature performance decreased significantly; in the aging wet-dry cycle coupling, the aging asphalt mixture is more susceptible to water erosion, and the first wet-dry cycle after the mix by the degree of water erosion is relatively small, along with the dynamic modulus of rebound. The dynamic modulus of resilience is relatively larger, and the high-temperature performance is relatively better, while the low-temperature performance is worse.

Predictive Modelling and Functional Group of Clay Soil Treated with Steel Slag and Calcium Carbide Residue

Swell-shrink subgrade soils like clay are rich in sulphate and exhibit a high rate of volume change by swelling and shrinking during wet and dry cycles, respectively, leading to heaves, cracks, and differential settlement of pavement layers. The aim of this study was to establish predictive simulation models and functional group of clay soil treated with steel slag and calcium carbide residue. Physical and geotechnical tests (such as California bearing ratio (CBR), compaction characteristics, and consistency parameters) were carried out on the unstabilised and stabilised clay soil. Using SPSS statistical software (version 23), multiple linear regression analysis was applied to the experimental data that relate CBR to compaction parameters and additive contents (steel slag and calcium carbide residues). The generated models gave a reliable coefficient of determination, R2 , of 0.990, and 0.998, which can be used to successfully predict both unsoaked and soaked CBR of the stabilised clay soil, respectively. Fourier transform infrared spectroscopy (FTIR) analysis was examined on the clay soil, the additives, and the stabilised clay soils. The FTIR analysis showed weak peaks at 1115 and 1103 cm-1 for all the stabilised clay soils, and this revealed that both additives drastically reduced the sulphate content in the clay soil, which consequently reduced the expansion, cracking, and disintegration rates. As a result, the clay soil's chemical bonding was enhanced through physico- chemical mechanisms.

Behaviors of anthracite under differential cyclic loading (DCL) after wet and dry cycling: Deformability and hysteresis characteristics

Behaviors of anthracite under differential cyclic loading (DCL) after wet and dry cycling: Deformability and hysteresis characteristics

Attenuation Law of Performance of Concrete Anti-Corrosion Coating under Long-Term Salt Corrosion

In saline soil areas, the concrete piers of concrete bridges experience long-term corrosion, mainly caused by chloride salts due to alternating temperature changes. Waterborne concrete coatings are prone to failure in this aggressive salt environment. Implementing coating protection measures can improve the durability of concrete and enhance the service life of bridges. However, the effectiveness and longevity of coatings need further research. In this paper, three types of waterborne concrete anti-corrosion coatings were applied to analyze the macro and micro surface morphology under wet–dry cycles and long-term immersion conditions. Various indicators such as glossiness, color difference, and adhesion of the coatings were tested during different cyclic periods. The chloride ion distribution characteristics of the buried concrete coatings in saline soil, the macro morphology analysis of chloride ion distribution regions, and the micro morphology changes of the coatings under different corrosion times were also investigated. The results showed that waterborne epoxy coatings (ES), waterborne fluorocarbon coatings (FS), and waterborne acrylic coatings (AS) all gradually failed under long-term salt exposure, with increasing coating porosity, loss of internal fillers, and delamination. The chloride ion content inside the concrete decreased with increasing depth at the same corrosion time, while the chloride ion content at the same depth increased with time. The chloride ion distribution boundary in the cross-section of concrete with coating protection was not significant, while the chloride ion distribution boundary in the cross-section of untreated concrete gradually contracted towards the concrete core with increasing corrosion time. During the corrosion process in saline soil, the coatings underwent three stages: adherence of small saline soil particles, continuous increase in adhered material area, and multiple layers of uneven coverage by saline soil. The failure process of the coatings still required erosive ions to infiltrate the surface through micropores. The predicted lifespans of FS, ES, and AS coatings, obtained through weighted methods, were 2.45 years, 2.48 years, and 2.74 years, respectively, which were close to the actual lifespans observed in salt environments. The developed formulas effectively reflect the corrosion patterns of different resin-based coatings under salt exposure, providing a basis for accurately assessing the corrosion behavior and protective effectiveness of concrete under actual environmental factors.

Model interpretation and microscopic characteristics of collapsibility evolution of compacted loess under dry-wet cycles

The evolution of loess microstructure exerts a direct impact on its collapse evolution during dry and wet (DW) cycles. In this study, a hydro-mechanical coupling numerical model considering DW cycles and mechanical loading was established by extending the Barcelona Basic model, meanwhile combining with the test results to reveal the effect of DW cycling on the collapse deformation and strength response of loess. Additionally, the microscopic mechanism of loess collapse evolution was revealed through microscopic tests. Results indicated DW cycles caused the net compaction of loess, with the first DW cycle exerting the most significant effect on its deformation, consequently deteriorating the loess. Wetting under constant loading leads to a collapse of macrostructures formed by aggregates. Moreover, DW cycles transformed the structural units from line and surface contact to point. The basic structural units exhibited obvious grade properties, in which DW cycles trigger the collapse of compound aggregates, with the number of relatively stable mononuclear aggregates and intergranular pores increasing. DW cycles in an open environment induced the loss of cementing materials such as soluble salts and reduced the bonding strength among basic structural units. This subsequently tended to weaken the structural properties of loess and decreased the mechanical properties.

Advances in Highly Ductile Concrete Research.

In recent years, high-ductility concrete (HDC) has gradually become popular in the construction industry because of its excellent ductility and crack resistance. Concrete itself is a kind of building material with poor tensile properties, and it is necessary to add a large number of steel bars to improve its tensile properties, which increases the construction cost of buildings. However, most of the research studies on high-ductility concrete are scattered. In this paper, the basic mechanical properties of high-ductility concrete and the effects of dry and wet cycles, freeze-thaw cycles, and salt erosion on the durability of high-ductility concrete are obtained by comprehensive analysis. The results show that the tensile properties of HDC can be significantly improved by adding appropriate fiber. When the volume fraction of steel fiber is 2.0%, the splitting tensile strength of concrete is increased by 98.3%. The crack width threshold of concrete chloride erosion is 55-80 μm, and when the crack width threshold is exceeded, the diffusion of CL-1 will be accelerated, and the HDC can control the crack within the threshold, thereby improving the durability of the concrete. Finally, the current research status of high-ductility concrete is analyzed, and the future development of high-ductility concrete is proposed.

Strength characteristics of phosphogypsum stabilized soil under dry and wet cycles

In order to study the strength characteristics of red clay stabilized by a high dosage of phosphogypsum, a mix proportion design was carried out at the ratio of phosphogypsum:red clay = 1:0.5, 1:1, 1:2, 1:3, 1:4, and 1:5 using 4%, 6%, and 8% cement as a curing agent, and this study was carried out through the unconfined compressive strength test, water stability test, California bearing ratio (CBR) test, and durability test. As the phosphogypsum content increases, the unconfined compressive strength of the mix shows a trend of increasing and then decreasing, the unconfined compressive strength of the mixture is the largest when the ratio is 1:3, and with the increase in the number of dry and wet cycles, the unconfined compressive strength of the mixture decreases, and the decay is the largest at 2–3 dry and wet cycles. The higher the phosphogypsum content, the better the water stability performance of the mix. In addition, the CBR value of the mixture can meet the requirements of freeway, primary highway, secondary highway bed, and embankment filler bearing ratio. In this paper, a mix durability test method is proposed to express the mix durability performance in terms of mass loss rate and durability coefficient; the mass loss rate of the mix increases with the increase in the number of wet and dry cycles, and the durability coefficient decreases with the increase in the number of wet and dry cycles; the higher the content of phosphogypsum, the better the durability performance of the mix.

Study on properties of alkali activated titanium gypsum artificial aggregate concrete

Abstract In order to solve the problem of raw material shortage and solid waste disposal in the construction industry, titanium gypsum was used as raw material to prepare titanium gypsum artificial aggregate by alkali-activated cold bonding. The physical properties and microstructure of aggregates were studied, they were used to replace natural aggregates in unfired bricks. The unburned aggregate of ternary cementitious material system (titanium gypsum, cement, silica fume) was designed, and the best artificial aggregate ratio was selected by physical performance analysis, XRD and SEM analysis. The unburned bricks were prepared by replacing natural gravel with different replacement rates. The physical properties and durability were analyzed by physical test, dry and wet cycle test, and the best utilization method was sought. Main research contents and conclusions: (1) When the ratio of titanium gypsum: cement: silica fume = 7: 2: 1, NaOH: CaO = 1: 1 as the activator, the comprehensive performance of artificial aggregate is the best. According to XRD and SEM analysis, the main products in the titanium gypsum artificial aggregate system are C-S-H and AFt. (2) The compressive strength of the unburned brick prepared by titanium gypsum artificial aggregate completely replacing natural gravel reached 31.40 MPa, and the water absorption rate was 10.18 %. The unburned brick specimens with different substitution rates showed good dry-wet cycle resistance after 15 dry-wet cycles.

Assessing the Settlement and Deformation of Pile-Supported Embankments Undergoing Groundwater-Level Fluctuations: An Experimental and Simulation Study

The intensification of extreme weather phenomena, ranging from torrential downpours to protracted dry spells, which trigger fluctuations at the groundwater level, poses a grave threat to the stability of embankments, giving rise to an array of concerns including cracking and differential settlement. Consequently, it is crucial to embark on research targeted at uncovering the settlement and deformation behaviors of pile-supported embankments amidst changes in water levels. In tackling this dilemma, a series of direct shear tests were carried out across a range of wet–dry cyclic conditions. The results confirmed that the occurrence of wet–dry cycles significantly impacted the resilience of silty clay. Additionally, it was observed that the erosion of cohesion and the angle of internal friction initially diminished sharply, subsequently leveling off, with the first wet–dry cycle exerting the most substantial influence on soil strength. Employing a holistic pile-supported embankment model, simulations revealed that variations in the groundwater level, fluctuations therein, varying descent rates, and periodic shifts in the groundwater level could all prompt alterations in soil settlement between embankment piles and could augment the peak tensile stress applied to geogrids. In summary, the orthogonal experimental method was utilized, indicating that, in terms of impacting embankment settlement under periodic water-level changes, the factors ranked in descending order were the following: pile spacing, pile length, embankment height, and the height of the groundwater table.

Effects of vetiver root on cracking of expansive soils and its mechanistic analysis

The study investigated the reinforcing effect of vetiver root on soil by conducting outdoor planting tests and indoor root tests. The cracking indexes of soil specimens with varying root contents were analyzed, and a statistical model was established to determine the relationship between the cracking indexes, the number of dry and wet cycles, and the root content. The study revealed the crack evolution law of vetiver-reinforced expansive soil. The study explored the mechanism of the vegetation root in inhibiting the cracking of expansive soil and determined the optimal planting density of vetiver grass through outdoor planting tests. The results indicate that: The surface crack rate (CR), total crack length (CL), and crack number (CN) in the root-soil specimen exhibited exponential growth with an increase in the number of wet and dry cycles. This growth was more pronounced during the first and second cycles. The vetiver root could effectively reduce soil crack formation, and the specimen's cracking resistance is positively correlated with the root content. With the root content increased, the CR, CN, and CL decreased. The logistic model is suited to the CL of added root soil. The logistic model is more suitable for the growth model of the CR of the expansive soil with low root content, while the Boltzmann model is more suitable for the growth model of the CR of the expansive soil with high root content. Width of crack (CW) is better suited to the DoseResp growth model. The Boltzmann model is more applicable to the CN in expansive soils with low reinforcement, while the logistic growth model is more suitable for the development of CN above 0.21% root content. The development of the crack network was influenced by two key factors: the root content and the number of wet and dry cycles. Under the condition of planting roots, the development of crack networks in expansive soil differs from that of expansive soil with added roots, and there is no clear pattern to follow. The inhibitory effect of the vetiver root on cracking of expansive soil is related to the planting density of vetiver.

Fibre hornification improves the long-term properties of hemp fibre-reinforced fly ash-based geopolymer mortar

The study investigates the impact of the fibres’ hornification, subjected to 5 wetting/drying cycles, on the physical and mechanical properties of short hemp fibre-reinforced fly ash-based geopolymer mortars at distinct ages (1, 2.5 and 18 months) cured under laboratory conditions and additionally of the mortars underwent the accelerated ageing of 10 wet/dry cycles. The study reveals that fibres’ hornification induced fibrillation and fibres' cleaner surfaces, most likely enhancing fibres' dispersion within the matrix. This phenomenon leads to suppressing the degradation of all tested mortar’s properties. Considering the curing under laboratory condition, in the case of the density, the suppression is more pronounced in the long term. After 18 months, the hornificated fibre-reinforced mortar nearly matches the water absorption capacity of the plain mortar. Furthermore, the fibres’ hornification contributes to the enhancement in compressive- and flexural strengths of the reinforced mortar at the age of 18 months. In the long term, by increasing the pre-peak segment of the force-displacement curves, the fibres’ hornification slightly increases the energy absorption capacity of the raw fibre-reinforced geopolymer mortar. In the case of the mortars’ curing under wet/dry cycles, the hornification proves to slightly (10 %) improve the physical (increase in density, decrease in water absorption) and mechanical properties (increase in compressive- and flexural strength, as well as energy absorption capacity) of the fibre-reinforced mortar. Due to the mortars’ exposure to the dry cycles (happen at 60 °C), the further geopolymerisation speeds up, which results in the denser matrix, increase in its compressive- and flexural strengths, but a general fibre/matrix bond deteriorates and therefore the fibre-reinforced mortars’ energy absorption capacity decreases, when compared to their counterpart tested at the same age but cured under laboratory condition.

Numerical analysis on crystallization inside porous sandstone induced by salt phase change

The behavior of water and salt inside porous sandstone is crucial for determining the durability of stone heritage. This involves multiphase coupled processes, yet previous analyses have paid insufficient attention to the spatial and temporal characterization of solution-crystal phase change. Based on the salt crystallization experiments, theoretical models and numerical computational frameworks are synthesized to simulate multiphase processes. Subsequently, equations are established for coupled water-salt-heat-mechanical interactions in the multiphase media. Then, the critical state of solution-crystal phase change is analyzed through the evolution of saturation, crystallization pressure, and porosity. The findings indicate rapid solution saturation growth at positions with minimal wetting front fluctuations, leading to initial crystallization. Further tracing reveals that crystallization evolves through discrete crystallization, annular crystallization, and crystallization expansion stages. By investigating the crystallization pressure and the crystal morphology, it is possible to quantify the dynamics of crystal pressure on constraint surfaces and solution pressure. In addition, the change in porosity can be observed by simulation of dry and wet cycles to obtain crystallization initiation. The numerical calculations agree well with the experimental results, providing valuable insights into the deterioration mechanism induced by salt crystallization in the porous sandstone of Dazu Rock Carvings.

Corrosion inhibition performance and mechanism of triethanolamine-triisopropanolamine rust inhibitor in the simulated concrete pore solution

In this research, aiming to deal with the accelerated corrosion deterioration of steel reinforcement in reinforced concrete in harsh environments, a highly efficient rust inhibitor (triethanolamine (TEA)-triisopropanolamine (TIPA)) (abbreviated as TT), which TEA and TIPA compounded in a ratio 4:6, was proposed. The synergistic rust inhibition effect of TEA and TIPA on steel in the simulated concrete pore solution (SCPS), and its corrosion inhibition performance were investigated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), dry and wet cycling, and scanning electron microscopy (SEM) measurements. The results showed that TT inhibitor could obviously inhibit the corrosion of steel in the SCPS and could inhibit both cathode and anode. The electrochemical corrosion inhibition performance was the most excellent at the dosage of 1.0 %, and the maximum corrosion inhibition efficiency (η1) reached 95.39 %. After 150 times of dry and wet cycling, the percentage of the corrosion area (S), and corrosion inhibition efficiency (η2) with 1.0 % TT inhibitor were 9.3 % and 84.03 %, respectively, and the mass loss rate (M) decreased by 68.4 %, indicating a better rust inhibition performance. The adsorption of the TT inhibitor conformed to the Langmuir adsorption isotherm and inhibited the corrosion of steel by forming a protective film on steel surface through physicochemical adsorption. This study is of great significance to provide new perspectives and improvement measures to build up the deterioration and extend the service life of reinforced concrete in harsh environments.

A Fractional-Order Creep-Damage Model for Carbonaceous Shale Describing Coupled Damage Caused by Rainfall and Blasting

In order to better understand the shear creep behavior of weak interlayers (carbonaceous shale) under the coupling effect of the rainfall dry–wet cycle and blasting vibration, as well as quantitatively characterize the coupled damage of the rainfall dry–wet cycle and blasting vibration, a series of shear creep tests were carried out. The results show that the combined damage of the rainfall dry–wet cycle and blasting vibration greatly intensifies the creep effect of carbonaceous shale, leading to an increase in deceleration creep time, an increase in steady-state creep rate, and a decrease in long-term strength. The coupling damage of the rainfall dry–wet cycle and blasting vibration in carbonaceous shale was quantitatively characterized. Based on the fractional-order theory, a fractional-order creep-damage constitutive model (DNFVP) was established by introducing the Abel dashpot to describe the coupled damage of the rainfall wet–dry cycle and blasting vibration and the nonlinear creep acceleration characteristics. The three-dimensional creep equation of the model was derived. The effectiveness of the DNFVP model was verified through the inversion of model parameters and fitting of experimental data, providing a basis for in-depth research on the long-term stability of high slopes in mines with weak interlayers.

Experimental study on the axial compressive mechanical performance of concrete short columns jointly confined with CC and CFRP after sulfate attack

By conducting axial compression tests on square concrete columns jointly reinforced by concrete canvas (CC) and carbon fiber-reinforced polymer (CFRP) after sulfate attack, the influences of the number of CFRP layers, the degree of erosion (number of wet and dry cycles) and the number of CC layers on the mechanical properties under axial compression were researched, and the failure morphologies, bearing capacities and deformation capacities of square concrete columns with joint reinforcement were analyzed. The results showed that sulfate attack would change the internal structure of the concrete, reduce the deformation capacities of the specimens, and make the brittle characteristics obvious. The square concrete column confined by CFRP after sulfate attack caused brittle damage to the specimen without obvious warning due to the stress concentration at the corner. The introduction of CC could relieve the corner stress concentration, improve the utilization of CFRP, avoid failure due to local destruction, and effectively improve the failure morphologies of the specimens so that the specimens had obvious precursors at failure. Based on the experimental study, the calculation model of the bearing capacity and the strain‒stress model of the square concrete column jointly confined by CC and CFRP after sulfate attack were established.

Contrasting rhizosheath formation capacities in two maize inbred lines: implications for water and nutrient uptake

Abstract Background and aims Rhizosheath, the soil attached to plant roots, may enhance drought resilience by improving water and nutrient uptake. This study evaluates the effects of rhizosheath formation on water and nutrient absorption from soils with different textures and moistures. Methods Two maize inbred lines R109B (Rh +) and Ky228 (Rh-), known for their distinct rhizosheath formation yet having identical root morphology, were cultivated in loamy sand and loamy soils. When plants were 45 days old, a controlled soil drying cycle was initiated and parameters such as plant transpiration rate (E), leaf water potential ($${\psi }_{leaf}$$ ψ leaf ), and soil water content/potential were monitored. At the end of soil drying cycle, the total nutrient uptake in the plants’ shoots was assessed. Results Rh + demonstrated a denser rhizosheath, particularly in loamy sand, correlating with increased root hair development. Rh + plants in loamy sand had a 1.73-fold increase in normalized mass rhizosheath compared to loam soil. In moderate moisture, Rh + exhibited improved soil–plant-water relationships, evidenced by higher midday E and $${\psi }_{leaf}$$ ψ leaf in loamy soil than Rh-. However, no significant differences were noted under severe drought between Rh + and Rh-, likely attributed to diminished root hairs functionality. In loamy sand, Rh + plants exhibited 1.5 times higher phosphorus uptake, 1.46 times higher calcium uptake, and 2.02 times higher manganese uptake compared to Rh-. Conclusion Root hair development is a crucial factor in rhizosheath formation. The efficacy of the rhizosheath in enhancing water and nutrient uptake is significantly influenced by soil texture and moisture conditions.

A Review of Drip Irrigation’s Effect on Water, Carbon Fluxes, and Crop Growth in Farmland

The substantial depletion of freshwater reserves in many pivotal agricultural regions, attributable to the dual pressures of global climate change and the excessive extraction of water resources, has sparked considerable apprehension regarding the sustainability of future food and water security. Drip irrigation, as an efficient and precise irrigation method, reduces water loss caused by deep percolation, soil evaporation, and runoff by controlling the irrigation dosage and frequency, thus improving the efficiency of water resource utilization. Studies have shown that compared with traditional irrigation methods, drip irrigation can significantly decrease water consumption, optimize the water–energy relationship by reducing soil evaporation, increase the leaf area index, and promote crop growth, thereby enhancing plant transpiration. Although more wet and dry soil cycles from drip irrigation may increase soil CO2 emissions, it also enhances crop photosynthesis and improves crop net ecosystem productivity (NEP) by creating more favorable soil moisture conditions, indicating greater carbon sequestration potential. The advantages of drip irrigation, such as a short irrigation cycle, moderate soil moisture, and obvious dry and wet interfaces, can improve a crop’s leaf area index and biomass accumulation, improve root dynamics, promote the distribution of photosynthetic products to the aboveground parts, and thus enhance crop yields. This study highlights the potential for the application of drip irrigation in arid regions where resource optimization is sought, providing strong technical support for the achievement of sustainable agricultural development. Future research needs to consider specific agricultural practices, soil types, and environmental conditions to further optimize the implementation and effectiveness of drip irrigation.