Soil Retention Research Articles

Spatiotemporal simulation of sustainable development based on ecosystem services under climate change.

This study explores the spatiotemporal distribution characteristics of ecosystem services (ESs) in the karst region of southeastern Yunnan under the backdrop of climate change. The study innovatively calculates the sustainable development goals (SDG) index based on ecosystem services (ESs). It employs the patch-generating land use simulation (PLUS) model to simulate future land use changes (LUCs) and uses the integrated valuation of ecosystem services and tradeoffs (InVEST) model to assess ESs under different scenarios. This research systematically evaluates the ESs and SDGs in karst regions within the context of climate change. The results indicate that: (1) Under all three scenarios in 2035, the trend of LUCs in the karst area of southeastern Yunnan is highly consistent, though the intensity and spatial configuration vary significantly. The least reduction in arable land area occurs under the shared socioeconomic pathways (SSP) 126 scenario, while water bodies and construction land show varying degrees of increase; (2) Regarding ESs, both water yield and soil retention exhibit an increasing trend across all scenarios by 2035, with the most notable rise under SSP126. Conversely, habitat quality and carbon storage show a decline, with the smallest decrease also under SSP126; (3) Analyzing the SDG index, the overall value is low in 2020. In future scenarios, the SDG index increases in the southern part while decreasing in the eastern part, indicating significant differences in regional sustainable development potential. Hotspots under SSP126 and SSP245 are concentrated in the densely vegetated southwest and eastern edge areas, while cold spots are mainly found in the heavily human-impacted central Yunnan urban agglomeration and Wenshan City. This study systematically explores for the first time the spatiotemporal dynamics of ESs in the karst region of southeastern Yunnan under different climate scenarios. It provides scientific evidence for regional ecological protection and land use planning.

Mitigating drought stress in fenugreek through synergistic effects of alanine and potassium-enriched biochar

Drought stress adversely affects plant growth, development, and yield. It can decrease seed germination, biomass accumulation, root proliferation, chlorophyll contents, and stomatal conductance. To overcome this critical issue, researchers suggest employing environmentally friendly approaches. The exogenous application of alanine (AL) acts as an osmolyte, which helps balance the cellular water under drought stress. It can also improve root architecture, biomass accumulation, and plant fertilizer use efficiency. Applying biochar can improve soil structure, water, and nutrient retention in soil, which are allied factors in enhancing plant growth under drought stress. Furthermore, the enrichment of potassium (K) in biochar also increases its availability to plants, directly regulating the stomatal conductance to alleviate drought stress. That’s why the current study aims to explore the combined effect of AL and potassium-enriched biochar (KBC) on fenugreek cultivated under drought stress. Four levels of AL (control, 2mM, 4mM, and 6mM) were applied with 0%, 1%, and 2% KBC in three replicates. Results showed that 2mM AL + 2%KBC showed significant improvement in plant length (5.24%), plant fresh weight (25.36%), plant dry weight (16.23%), chlorophyll a (7.80%), chlorophyll b (15.83%), total chlorophyll (10.65%) over the control under drought stress. A significant increase in shoot N, P, and K concentration compared to control under drought stress also validated the effectiveness of 2mM AL + 2%KBC. In conclusion, 2mM AL + 2%KBC is an effective amendment for alleviating drought stress in fenugreeks. Under drought stress, growers are recommended to apply 2mM AL + 2%KBC to achieve better fenugreek growth.

An innovative approach to prioritizing soil conservation areas under diverse scenarios by leveraging the complementary roles of soil retention services and soil erosion indicators

An innovative approach to prioritizing soil conservation areas under diverse scenarios by leveraging the complementary roles of soil retention services and soil erosion indicators

Evaluating the effect of biochar rate and combination with fertilizer on the dynamics of soil nitrogen supply in tea plantation

Tea plantations commonly receive substantial quantities of nitrogen (N) fertilizer, with potential for considerable N loss to occur. This study assessed N retention in acidic tea plantation soil and examined how different biochar application rates and fertilizer combinations affect N dynamics, highlighting the importance of innovative technologies to monitor and enhance N supply management. This research adopted a modified 2-week aerobic incubation and ion-exchange membrane (IEM) techniques to evaluate the soil N supply in tea plantations following early-summer top-dressing as influenced by various biochar rates and fertilizer combinations. We quantified the amount of mineralized N in acidic tea plantation soils during the summer. Our results show that biochar enhances soil N supply not by increasing N mineralization directly but by improving soil mineral N retention. Notably, a threshold effect was identified at biochar application rates of 20–30 tonnes ha−1. The window for maximizing the effectiveness of inorganic fertilizers applied during the summer months in tea plantations could only be 2–4 weeks. The use of biochar-based organic fertilizers can enhance this period by enhancing N retention and availability in the soil. Measuring N mineralization potential via aerobic incubations and N exposure using IEM technology effectively elucidated soil N dynamics during summer period.

Examining Ecology–Agriculture–Economy Nexus Shifts to Propose Win–Win–Win Pathways for Sustainable Development in Mountainous Areas: Insights From the Greenest City in China

ABSTRACTEcosystem restoration projects (ERPs) are effective methods for reversing land degradation. However, the dynamic responses of the ecology–agriculture–economy nexus to ERPs and socioeconomic development have yet to be systematically analyzed. To address this issue, we adopted an ERP hotspot as a basis for exploring the evolution regimes of sectoral variables and their determinants. ERPs facilitated vegetation restoration and strengthened carbon sequestration and soil retention, whereas grain productivity declined sharply since 2000 because of industrial and planting structure adjustments. Economic growth was accompanied by marked industrial transformation; the dominant role of the primary industry was gradually replaced by that of other industries, with the population and employment structures changing accordingly. Rural population loss weakened the agricultural production capacity, with the promotion of economic crops further degrading the dominant role of grain crops. Such nexus shifts indicated that positive progress in the ecological and economic sectors should be further optimized to reserve sufficient space for agricultural production and industrial development, instead of relying solely on expanding afforestation areas. Notably, the temporary synergic co‐evolution of nexus sectors from 2008 to 2022 is not stable because of the low grain self‐sufficiency ratio, which might threaten the sustainability of social‐ecological systems. Therefore, agricultural production efficiency must be improved through large‐scale production and improvements in agricultural production conditions to sustain the grain supply. The nexus perspective enriches our understanding of interlinkages among sectors in different phases, facilitating the formulation of coordinated strategies for regional sustainable development.

Soil moisture partitioning strategies in blowouts in the Hulunbeier grassland and response to rainfall

IntroductionSoil moisture and soil water retention capacity are key influencing factors for the normal growth and development of vegetation. Understanding the dynamic change characteristics of soil moisture in blowouts and soil water retention capacity is of great significance for the management of blowouts.MethodsThis study employs drying and in situ monitoring methods to select typical blowouts in different regions (sand pits, fringe zones, sand accumulation zones, and sand-grass transition zones) on the Hulunbuir Grassland. A large area of natural grassland surrounding these regions was chosen as the control (CK). Soil moisture at depths of 20, 40, 60, 100 and 200 cm below the surface was measured along the soil profile using the ECH2O-10HS soil moisture automatic monitoring instrument. The HOBO-RG3-M self-recording rain gauge was used to monitor rainfall. Soil water storage, coefficient of variation, and Pearson’s correlation coefficient were calculated to study the differences in soil moisture and the dynamic change regularity in soil moisture under different rainfall conditions. This research provides important theoretical support for the soil moisture distribution and vegetation restoration in the blowouts of the Hulunbuir Grassland.Results and discussionThe volumetric water content of the soil in the blowouts was 15.95%, the volumetric soil water content in different parts of the soil varied from low to high as follows: sand pit-I < sand-grass transition zone-IV < fringe zone-II < CK < sand accumulation zone-III. The soil volumetric water content of the 0–40 cm soil layer of the blowout was higher than 17.47%, and the soil volumetric water content of the 40–200 cm soil layer ranged from 12.13% to 17.47%. The volumetric water content of soil in various parts of the blowouts under different rainfall amounts had significant differences, with rainstorms and heavy rainfall effectively recharging the blowouts to a depth of 200 cm, and the blowouts responded strongly to heavy rainfall (71.5 mm). A gradual recovery of the pre-rainfall volumetric soil moisture content was seen approximately a week after rainstorms. The water retention and storage capacity of blowout soils was significantly higher than that of CK, the soil water storage capacity of different zones ranked in descending order as the sand accumulation zone (1875.38 mm) > edge zone (1373.22 mm) > CK (1188.36 mm) > sand pit (1000.39 mm) > sand–grass transition zone (803.90 mm). The correlation coefficient of sand pits and sand cover was 0.5612, and that of sand accumulation zones and sand cover was 0.5845, which confirmed that sand cover enhanced the water retention capacity of the localized area of blowouts (sand accumulation zones).

Biochar Amendment as a Mitigation Against Freezing–Thawing Effects on Soil Hydraulic Properties

Seasonal freeze–thaw cycles compromise soil structure, thereby increasing hydraulic conductivity but diminishing water retention capacity—both of which are essential for sustaining crop health and nutrient retention in agricultural soils. Prior research has suggested that biochar may alleviate these detrimental effects; however; further investigation into its influence on soil hydraulic properties through freeze–thaw cycles is essential. This study explores the impact of freeze–thaw cycles on the soil water retention and hydraulic conductivity and evaluates the potential of peanut shell biochar to mitigate these effects. Peanut shell biochar was used, and its effects on soil water retention and unsaturated hydraulic conductivity were evaluated through evaporation tests. The findings indicate that freeze–thaw cycles predominantly affect clay’s ability to retain water and control hydraulic conductivity by generating macropores and fissures; with a notable increase in conductivity at high matric potentials. The impact lessens as matric potential decreases below −30 kPa, resulting in smaller differences in conductivity. Introducing biochar helps mitigate these effects by converting large pores into smaller micro- or meso-pores, effectively increasing water retention, especially at higher content of biochar. While biochar’s impact is more pronounced at higher matric potentials, it also significantly reduces conductivity at lower potentials. The total porosity of the soil increased under low biochar application rates (0% and 1%) but declined at higher application rates (2% and 3%) as the number of freeze–thaw cycles increased. Furthermore, the characteristics of soil deformation during freeze–thaw cycles shifted from frost heaving to thaw settlement with increasing biochar application rates. Notably, an optimal biochar application rate was observed to mitigate soil deformation induced by freeze–thaw processes. These findings contribute to the scientific understanding necessary for the development and management of sustainable agricultural soil systems.

Oxidized alkaline biochar and phosphate solubilizing bacteria mixture enhances direct seeded maize yield in an acid soil

Maize is an important cereal in many developed and developing countries of the world. One of the primary challenges for maize cultivation is soil acidity. Acidic soil is a major constrain in achieving food security requiring sustainable solutions. Biochar, a pyrogenic carbon-rich material, carries reactive surfaces (i.e., high surface area and variable surface charges). Therefore, it facilitates nutrient retention in soil and gradual release to plants, thereby supporting crop growth. However, the combine effects of functionalized biochar with microbes on phosphorus (P) bioavailability and plant performance remain unclear. This study investigates the application of different oxidized biochars (i.e.,fresh rice husk biochar (RHB), pH adjusted oxidized RHB and control) and phosphate solubilizing bacteria (i.e., <em>Pseudomonas aeruginosa</em>, and control) on soil properties including phosphorus dynamics and the performance of maize grown in an acid soil. Biochar was oxidized using 10% hydrogen peroxide while the pH was adjusted to 8.5. Maize was grown in pots having 20 kg of soil or soil-biochar mixture. Overall, biochar and microbes treatments increased soil phosphorus bioavailability and maize yield with a greater effects in the oxidized biochar giving a significant biochar × microbes interactions. Specifically, oxidized biochar when applied with <em>Pseudomonas aeruginosa</em> increased P availability by 380 % which then contributed to yield increment (291%). We also observed a significant reduction in available aluminum (Al) concentration (40% ) compare to the control. These improvement in yield might have occurred due to an increase soil pH, P bioavailability (r<sup>2</sup>= 0.74), and a reduction in Al toxicity (r<sup>2</sup>= 0.36).Findings of this study could have significant implications for crop production in acidic soil.

Synthesis and Characterization of Sodium Carboxymethyl Cellulose/Chitosan/Polyvinyl Alcohol Hydrogels to Removal Ionic Dyes and Their Biodegaration

ABSTRACTHydrogels from polyvinyl alcohol (PVA), sodium carboxymethyl cellulose (CMC), chitosan (CS) were syntheised via gamma irradiation at different radaition dose; 0, 2.5, 5, 10, and 20 kGy. The syntheized hydrogels were chataerized by gelation (%), swelling (%), XRD, and SEM to confirm the hydrogel formations. The hydrogels were used to remove dyes of direct blue 1 (DB1), methylene blue (MB) from their aqueous soltions. The effect of contact time, feeding intial concentration and temperature were investigated. The adsorption of kinetics models such pseudo first‐order, pseudo second‐order, and Bangham were studied. The results of kinetics invetsiation showed that DB1 obeys pseudo second‐order, while MB obeys pseudo first‐order. Moreover, the adsorption iostherms of Langmuir isotherm model, Freundlich, Redlich–Peterson isotherm, Sips isotherm, Hill isotherm were applied. The outcome results referred that both of DB1 and MB obey Langmuir model. Further, the Soil degradability test of pure hydrogels and hydrogels‐adsorbed DB1 and hydrogels‐adsorbed MB was carried out by burial under soil for 14 days. The results showed the pure hydrogels exposed rapid soil degradability than hydrogels‐adsorbed DB1 and hydrogels‐adsorbed MB. Furthermore, water‐holding capacity and water retention of sandy soils of hydrogels were studied. The results of water‐holding capacity and water retention showed that the hydrogels that prepared at 20 kGy is highest one than that prepared at 2.5 kGy is the lowest one.

Optimizing soil remediation with multi-functional L-PH hydrogel: Enhancing water retention and heavy metal stabilization in farmland soil.

Agricultural soils face severe challenges, including water scarcity and heavy metal contamination. Optimizing soil remediation efficiency while minimizing inputs is essential. This study assessed the water retention and heavy metal adsorption properties of L-PH hydrogel through aqueous experiments. Fourier Transform Infrared (FTIR) and X-ray Photoelectron Spectroscopy (XPS) elucidated the adsorption mechanisms. The results showed that L-PH hydrogel exhibited high water absorption efficiency, with Zn2+ removed via electrostatic interactions and cation exchange, and Cd2+ and Cu2+ adsorbed through coordination complexation. Soil experiments tested water retention and heavy metal leaching under various application methods (M1=0-10cm mixed, M2=10-20cm mixed, T1=5-10cm layered, T2=10-15cm layered) and rates (NL=0%, L1=0.1%, L2=0.2%, L3=0.5%). L-PH reduced water infiltration, enhanced soil water retention, and decreased heavy metal mobility across all treatments. The highest water retention was observed in the M1 method. Under M1L1, cumulative leaching of Cd2+, Cu2+, and Zn2+ decreased by 68.84%, 33.44%, and 83.60%, respectively. Two-way ANOVA revealed that application rate had a greater effect on leaching than the method. FTIR and XRD analyses showed that at low concentrations (L1, L2), L-PH formed coordination bonds with Cd2+ and Cu2+, creating Cd(HCOO)2·2(NH2)2CO and Cu(HCOO)(OH) in the soil. Zn2+ was stabilized through adsorption and precipitation, forming Zn(OH)2, thereby reducing leaching. Higher concentrations of L-PH may have further interacted with Zn, leading to dissolution and adsorption/precipitation processes. Redundancy analysis (RDA) analysis suggests that an increase in organic carbon and moisture content in soil aggregates larger than 2mm, along with a decrease in bioavailable heavy metals, may enhance heavy metal stabilization, reducing their movement and leaching. This study offers valuable insights into addressing the twin challenges of water scarcity and heavy metal pollution.

Integrating Ecosystem Service Assessment, Human Activity Impacts, and Priority Conservation Area Delineation into Ecological Management Frameworks

The comprehensive protection and restoration of mountains, rivers, forests, farmlands, lakes, grasslands, and deserts is critical for enhancing ecological environmental quality and fulfilling the aspirations of ecological civilization in the modern era. Centered on the key project area of the Mountain-River Project within the Luohe River Basin of the Eastern Qinling Mountains, this study employs the InVEST model to assess spatiotemporal variations in habitat quality (HQ), water yield (WY), carbon sequestration (CS), and soil retention (SR) for the years 2000, 2010, and 2020. This study further examines the trade-offs and synergies among these ecosystem services, integrates the Ordered Weighted Averaging (OWA) and GIS methodology with human activity patterns, determines the optimal management scenario, and offers targeted recommendations for optimization. The findings reveal that areas of high habitat quality, carbon sequestration, and soil retention are predominantly concentrated in the western and southwestern regions of the basin, whereas high-value zones of water yield are primarily situated in the southern and southwestern sectors. Habitat quality demonstrates significant synergies with other ecosystem services, whereas water yield presents a notable trade-off with soil retention. By conducting a comparative analysis of protection efficiency, we identified priority conservation areas predominantly located in the southern and southwestern regions of the basin. Moreover, through overlaying the priority conservation zones with the Human Footprint Index (HFI), the priority conservation area was precisely delineated to encompass 5.41 × 105 hectares. This methodology provides critical guidance for the implementation of the Mountain-River Project and offers substantial value in scientifically advancing ecological restoration initiatives.

Biochar and Humic Substances Roles for Nitrogen Transformation in Agriculture

Sustainable soil fertility management is crucial for global food security and addressing environmental challenges from modern agriculture. Soil health, alongside water availability, is essential for crop productivity, and soil degradation threatens food security by lowering yields and intensifying climate change. Nitrogen (N) cycling is central to soil fertility, supporting plant growth through nutrient replenishment and microbial activity. However, N is often lost through leaching, volatilization, and denitrification, reducing nitrogen use efficiency (NUE) and contributing to water pollution and greenhouse gas (GHG) emissions. Optimizing nitrogen retention in soils is vital for improving productivity and minimizing environmental harm. Biochar (BC) and humic substances (HSs) have emerged as effective strategies for improving N management. BC enhances soil fertility by increasing soil pH, cation exchange capacity, and water retention, while reducing nutrient leaching and promoting carbon sequestration. HSs, including humic acids (HA), fulvic acids (FA) and humin (HU), improve nutrient cycling by stimulating microbial activity and enhancing nutrient transport. Together, BC and HSs provide synergistic benefits for soil health, particularly in challenging environments like saline or nutrient-depleted soils. This review highlights the roles of BC and HSs in enhancing soil fertility, promoting N mineralization, and improving crop productivity. It emphasizes their potential for sustainable agricultural practices, climate change mitigation, and long-term soil health. Keywords: Biochar, Climate changes, Humic substances, Remediation, Soil fertility.

"From Waste to Wonder": Comparative Evaluation of Chinese Cabbage Waste and Banana Peel Derived Hydrogels on Soil Water Retention Performance.

Under the increasing severity of drought issues and the urgent need for the resourceful utilization of agricultural waste, this study aimed to compare the soil water retention properties of hydrogels prepared from Chinese cabbage waste (CW) and banana peel (BP) using grafting techniques with acrylic acid (AA) and acrylamide (AAm). Free radical polymerization was initiated with ammonium persulfate (APS), and N, N'-methylene bisacrylamide (MBA) served as the crosslinking agent to fabricate the grafted polymer hydrogels. The hydrogels were subjected to detailed evaluations of their water absorption, reusability, and water retention capabilities through indoor experiments. The optimal hydrogel was identified and its applicability in wheat seedling growth was assessed. The findings revealed that the CW-gel, with an equilibrium swelling ratio of 551.8 g/g in ultrapure water, demonstrated remarkable performance and sustained a high water retention of 57.6% even after drying, which was markedly superior to that of the BP-gel. The CW-gel with the best comprehensive properties significantly improved water retention in sandy soil by 78.2% and prolonged the retention time by five days, indicating its potential for long-term irrigation management. In contrast, the BP-gel showed better performance in clay soil, with an increased water-holding capacity of 43.3%. The application of a 1.5% CW-gel concentration under drought stress significantly improved wheat seedling growth, highlighting the role of hydrogels in agriculture and providing a new path for sustainable water resource management in dryland farming.

Ecosystem Services Trade-Offs in the Chaohu Lake Basin Based on Land-Use Scenario Simulations

Amid global environmental degradation, understanding the spatiotemporal dynamics and trade-offs of ecosystem services (ESs) under varying land-use scenarios is critical for advancing the sustainable development of social–ecological systems. This study analyzed the Chaohu Lake Basin (CLB), focusing on four scenarios: natural development (ND), economic priority (ED), ecological protection (EP), and sustainable development (SD). Using the PLUS model and multi-objective genetic algorithm (MOGA), land-use changes for 2030 were simulated, and their effects on ESs were assessed quantitatively and qualitatively. The ND scenario led to significant declines in cropland (3.73%) and forest areas (0.18%), primarily due to construction land expansion. The EP scenario curbed construction land growth, promoted ecosystem recovery, and slightly increased cropland by 0.05%. The SD scenario achieved a balance between ecological and economic goals, maintaining relative stability in ES provision. Between 2010 and 2020, construction land expansion, mainly concentrated in central Hefei City, led to a marked decline in habitat quality (HQ) and landscape aesthetics (LA), whereas water yield (WY) and soil retention (SR) improved. K-means clustering analysis identified seven ecosystem service bundles (ESBs), revealing significant spatial heterogeneity. Bundles 4 through 7, concentrated in mountainous and water regions, offered high biodiversity maintenance and ecological regulation. In contrast, critical ES areas in the ND and ED scenarios faced significant encroachment, resulting in diminished ecological functions. The SD scenario effectively mitigated these impacts, maintaining stable ES provision and ESB distribution. This study highlights the profound effects of different land-use scenarios on ESs, offering insights into sustainable planning and ecological restoration strategies in the CLB and comparable regions.

Date Palm Waste-Derived Biochar for Improving Hydrological Properties of Sandy Soil Under Saturated and Unsaturated Conditions

Water conservation and effective irrigation management are vital for sustainable agriculture in arid regions. While organic soil amendments have been widely used to enhance water retention in sandy soils, research on the use of date palm waste-derived biochar remains limited. Thus, this study aimed to explore the innovative application of biochar produced from date palm waste, focusing on its effects on the hydrological properties of sandy soil. Biochars of varying particle sizes (0.5, 1, and 2 mm) and pyrolysis temperatures (300 °C, 450 °C, and 600 °C) were produced and their impacts were assessed under both saturated and unsaturated conditions on soil hydrological properties. The biochar was incorporated into soil columns at application rates of 0%, 1%, 3%, and 5% (w/w) within a 10 cm layer on top of 35 cm deep soil columns. The soil columns were placed vertically into water basins for saturation. Evaporation, infiltration, and saturated hydraulic conductivity were measured. The findings revealed that the application of 1%, 3%, and 5% biochar significantly increased soil water retention by 36.80%, 34.18%, and 29.66%, while cumulative evaporation decreased by 7.30%, 2.00%, and 1.35%, respectively, as compared to the control. Water retained at the end of the experiment was increased by 100.63%, 112.29%, and 101.68%, while unsaturated hydraulic conductivity decreased by 21.27%, 26.15%, and 26.17% after amending the soil with 1%, 3%, and 5% biochar, respectively, as compared to the control. The water retention ranged between 30.34 and 42.51%, 22.59 and 43.20%, and 22.48 and 38.81% for biochar produced at 300 °C, 450 °C, and 600 °C, respectively. Water infiltration rate and pore size was decreased with the increased pyrolysis temperature. Overall, the application rates of 3% and 5% with particle sizes of 1 and 0.5 mm and low pyrolysis temperature were most efficient for improving soil properties such as water retention, reducing unsaturated hydraulic conductivity, reducing the rate and volume of infiltration, and enhancing the micro-porosity reduction of sandy soils. In a nutshell, this study highlights the potential of date palm waste-derived biochar as an effective soil amendment, significantly enhancing water retention by up to 112.29% and reducing evaporation. By optimizing irrigation management in sandy soils, these findings contribute to more sustainable agricultural practices.

Coconut residues increase light fraction of organic matter and water retention in semi-arid sandy soil under irrigated cultivation

ABSTRACT Coconut palm cultivation is associated with the generation of a large amount of residues, mainly from coconut shells, and their utilization in agriculture can represent an opportunity in the context of circular economy and climate change. This study aimed to determine the effect of coconut shell deposition on carbon (C) stocks, organic matter quality, and soil water retention in coconut palm cultivation in the Brazilian semi-arid region. The study was conducted in a commercial coconut palm cultivation area in Petrolina, Pernambuco State, Brazil, forming a chronosequence with 0, 2, 4, 5 and 6 years of coconut shells or coconut leaves application on soil surface. Carbon contents and stocks up to 0.40 m deep, the physical quality of soil organic matter, and soil water retention were evaluated. Coconut leaves and coconut shells increased organic C content in the surface layers of the soil, but the addition of residues did not influence soil C stocks. The light fraction of organic matter (>53 µm) was more sensitive to the management studied, while the heavy fraction of organic matter (<53 µm) was not significantly changed by the evaluated treatments. Coconut shells deposition on the surface increased the available water content to 8.5 % in the soil up to 0.40 m deep, but the effects were more significant on the surface. The highest C contents in the fraction >53 µm and the highest soil water retention were observed three years after the deposition of coconut shells on the surface, which suggests the need for reapplying the residues after this period to maintain the benefits.

Correlation Analysis of Ecosystem Reduction and Retention Effects and Spatial Distribution of Soil Potential Toxicity Elements.

Soil contamination by potentially toxic elements (PTEs) poses a significant threat to crop quality and human health, making it a global concern. However, the distribution patterns of PTEs across different land-use types are not well understood. To investigate the relationship between the reduction and retention effects of various ecosystem types on soil PTEs, we analyzed five categories of target elements in 299 soil samples from the southeastern Yunnan Province. Using the intelligent urban ecosystem management system's surface source control (runoff) model, descriptive statistical methods, spatial interpolation analyses, and GIS, we simulated the effects of different ecosystem types on soil heavy metals. This approach allowed us to examine the spatial correlations among ecosystem reduction, retention, and PTE distribution in soils. Our results indicate that soil PTE concentrations were indicative of a high-background value area, with concentrations of arsenic, cadmium, copper, lead, and zinc exceeding risk screening values. The coefficients of variation for arsenic, cadmium, and lead were extremely high and attributable to high external anthropogenic interference. Soil heavy metal reduction and spatial distribution were affected by the ecosystem's control function, and different ecosystems had different reduction effects. The reduction simulations for As and Pb were concentrated in building areas, while those for Cd and Zn were primarily focused on water bodies. The reduction simulations for Cu were concentrated in the forested areas. In conclusion, ecosystem reduction and retention influence heavy metal distribution, which is essential when planning green ecological development and construction.

Salinity Effects on Soil Structure and Hydraulic Properties: Implications for Pedotransfer Functions in Coastal Areas

Understanding the effects of salinity on soil structure and hydraulic properties is critical for addressing environmental challenges in coastal saline and sodic areas. In this study, soil samples were collected from a coastal region in eastern China to investigate how salinity affected the soil structure and hydraulic properties based on lab experiments. A comprehensive soil dataset was also compiled from the experimental results to develop a salinity-based pedotransfer function (PTF-S) tailored to the coastal environment. The results showed that salinity significantly altered the soil aggregate size distribution and hydraulic properties. Higher salinity promoted the formation of larger aggregates (0.25–2 mm), particularly in silty clay soil. Salinity positively correlated with the saturated hydraulic conductivity (Ks) in sandy loam soil, regardless of the cation type (Na⁺ or Ca2⁺). By comparison, Na+ increased the Ks of silty clay soil up to a certain threshold, while Ca2+ enhanced the Ks regardless of the soil texture. Increased salinity also reduced the soil water retention of sandy loam soil; however, Na+ increased the soil water retention of silty clay soil and Ca2+ had different effects depending on the suction levels. The newly developed PTF-S model, which included the electrical conductivity (EC) and cation exchange capacity (CEC), showed better predictions for the volumetric water content (R = 0.886 and RMSE = 0.057 cm3/cm3) and log Ks (R = 0.991 and RMSE = 0.073 mm/h) than the traditional model that excludes the salinity variables EC and CEC (PTF-N) (R = 0.839 and RMSE = 0.066 cm3/cm3 for the volumetric water content, and R = 0.966 and RMSE = 0.140 mm/h for the log Ks). This study highlights the importance of developing salinity-based PTFs for addressing soil salinization challenges.

Transformation of Water Retention and Transport Function of Artificial Soils in Moscow

Transformation of Water Retention and Transport Function of Artificial Soils in Moscow

Ecosystem Services’ Response to Land Use Intensity: A Case Study of the Hilly and Gully Region in China’s Loess Plateau

The hilly and gully region of the Loess Plateau represents one of China’s most ecologically vulnerable landscapes, characterized by severe soil erosion, intensive land use, and pronounced disturbances to the structure and functionality of ecosystem services. Taking Zichang City as a case study, this research integrates grid-scale analysis with the InVEST-PLUS model and bivariate spatial autocorrelation techniques to examine the spatiotemporal dynamics and inter-relations of four critical ecosystem services—carbon storage, water yield, biodiversity, and soil retention—under varying land use intensity scenarios from 1990 to 2035. The findings indicate that (1) between 1990 and 2020, land use intensity in Zichang City steadily declined, exhibiting a spatial distribution pattern typified by central-area clustering and gradual peripheral transitions. (2) Across three development scenarios, the spatial distribution of the four ecosystem services aligned with the patterns observed in 2020, with central areas showing pronounced fluctuations, whereas peripheral regions experienced relatively minor changes. Specifically, from 1990 to 2020, the proportion of low-carbon storage areas increased by 2.89%, and high water yield areas expanded by 9.45%, while the shares of low habitat quality and low soil retention areas decreased by 5.59% and 6.25%, respectively. (3) A significant spatial autocorrelation was observed between land use intensity and the four ecosystem services, with widespread cold and hot spots reflecting dynamic spatial clustering patterns. These results offer valuable insights for optimizing land use strategies, improving ecosystem service performance, and advancing ecological conservation and sustainable development initiatives.