Soil Moisture Content Research Articles

Analysis of changes and influencing factors of stablization treatment effects and bioavailability after freeze-thaw: a case study of Pb-contaminated soil in a non-ferrous metal factory in Northeast China

IntroductionSolidification/Stabilization techniques are commonly used for the containment and isolation of Pb-contaminated soil, but they cannot reduce the amount of contaminants. Freeze – thaw after stabilization may affect Pb’s environmental behavior and increase the uncertainty of environmental risk.MethodsIn vitro experiments can simulate the bioavailability of heavy metals to the human body, accurately assessing their environmental health risks. In this study, soil samples from Pbcontaminated site are collected from a non-ferrous metal plant in Northeastern China. Through the results of stabilization and freeze–thaw after stabilization experiments, analyzing the changes of physicochemical property, Pb treatment effects (total concentration, leaching concentration, and occurrence forms) and microbial communities, and studying the influencing factors of Pb’s bioavailability.Result and discussionThe results show that stabilization and freeze – thaw after stabilization directly alter soil physicochemical property, thereby affecting the leaching and occurrence form of Pb and microbial communities, and closely related to changes in bioavailability of Pb. Both stabilization and freeze–thaw treatment reduced the leaching concentration of Pb, decreased the proportion of available Pb (acid-soluble state, oxidation state and reduction state), increased the bioavailability of Pb in the gastric phase, but decreased in the intestinal phase; And the dominant bacterial phylum in the soil changed to Firmicutes, the dominant bacterial genus changed to Bacillus; The analysis of the results shows that the bioavailability of Pb is related to soil pH, cation exchange capacity (CEC), soil organic matter (SOM), soil moisture content (SMC), Pb (leaching, acid soluble state, oxidation state, residual state), types of microorganisms in soil.

Study on Soil Water and Nitrogen Transport Characteristics of Unidirectional Intersection Infiltration with Muddy Water Fertilization Film Hole Irrigation

This study investigated the effects of film hole diameter and soil bulk density on the unidirectional intersection infiltration laws of muddy water fertilization film hole irrigation. Indoor soil box infiltration experiments were conducted. The thickness of the sediment layer, cumulative infiltration amount per unit area, vertical wetting front transport distance, moisture distribution in the wetting body, and nitrate and ammonium nitrogen transport laws were observed and analyzed. The results indicated that both the thickness of the sediment layer and the cumulative infiltration per unit area are inversely correlated with film hole diameter and soil bulk density. Conversely, the vertical wetting front transport distance and nitrogen content are positively correlated with film hole diameter, while exhibiting a negative correlation with soil bulk density. Notably, the initial point of intersection for the moist body was located below the soil surface, with the peak vertical soil moisture content at the intersection approximately 1.5 cm beneath the surface. The distribution pattern of soil nitrate nitrogen at the conclusion of infiltration mirrored that of water content, characterized by a sharp decline near the wetting front. In contrast, soil ammonium nitrogen content decreased significantly in the shallow soil layer as soil depth increased, without a corresponding abrupt decrease near the wetting front. These findings may provide a theoretical foundation for future research on the intersection infiltration laws of muddy water fertilization through film hole irrigation.

Soil Moisture Content Prediction in Loam Soil with RFR Model

Soil moisture content (SMC) is an important factor in agricultural productivity; it has an impact on crop growth, water use efficiency, and soil health. However, accurately predicting SMC, especially at deeper soil layers, remains challenging due to high variability and limited spatiotemporal data resolution. This study developed and evaluated a Random Forest Regression (RFR) model to predict SMC in loam soil at five different depths (5, 20, 40, 60, and 80 cm) utilizing meteorological data (temperature, humidity, precipitation, wind speed, and solar radiation) and vegetation indices: the Normalized Difference Vegetation Index (NDVI) and the Normalized Difference Moisture Index (NDMI). Data were collected during the maize vegetation season in 2023 in Mosonmagyaróvár, Hungary. The results showed that the mean SMC ranged from 12.61% to 16.19%. Correlation analysis demonstrated that precipitation and NDMI had the strongest positive correlation with SMC, especially at shallower depths r = 0.78 at 5 cm depth, Solar radiation had a moderate correlation with SMC, especially at the deeper depths. The RFR model performed well at all depths, achieving an R² of 0.86 at 5 cm depth; the model accuracy enhanced at deeper layers, achieving R² values of 0.91 and 0.94 at 60 and 80 cm depths, respectively. The most significant predictors according to the feature importance analysis were precipitation, humidity, and NDMI, with NDMI playing a crucial role in subsurface moisture retention at deeper depths. These findings highlight the potential for machine learning algorithms to optimize irrigation approaches and improve water management in precision agriculture.

Biomass Allocation in Gentianella turkestanorum is Driven by Environmental Factors and Functional Traits

Exploring the elevation distribution characteristics, biomass allocation strategies, and the effects of elevation, soil factors, and functional traits on the biomass of Gentianella turkestanorum (Gand.) Holub is of great significance for the production, development, utilization, and protection of the medicinal material resources. In this study, we investigated the biomass and functional traits of the root, stem, leaf, and flower of G. turkestanorum, analyzing their elevation distribution patterns, allometric growth trajectories, and their correlations. The results showed that the biomass of different organs of G. turkestanorum decreases with increasing elevation, and the belowground biomass/aboveground biomass increases with elevation. The flower biomass accounts for 59.24% of the total biomass, which was significantly higher than that of other organs. G. turkestanorum biomass follows the optimal allocation theory, adopting a ‘pioneering’ growth strategy at low elevations and a ‘conservative’ strategy at high elevations. Chlorophyll content and leaf thickness of G. turkestanorum were positively correlated with elevation, but leaf dry matter content and the number of flowers were negatively correlated with elevation. Compared to functional traits, elevation and soil factors have a stronger explanatory power regarding the biomass of G. turkestanorum. Elevation, soil moisture content, pH, available phosphorus, total nitrogen, and ammonium nitrogen significantly affect the biomass of G. turkestanorum, with only pH showing a positive correlation with biomass. Among these factors, elevation, soil moisture content, and pH significantly impact the accurate prediction of G. turkestanorum biomass. The number of flowers, crown width, root length, root diameter, and leaf dry matter content all have a significantly positive correlation with the biomass of G. turkestanorum, with the number of flowers and root diameter making significant contributions to the accurate prediction of biomass. Elevation can directly affect the biomass of G. turkestanorum and can also indirectly affect it through other pathways, with the direct effect being greater than the indirect effect.

Goose grubbing and warming suppress summer net ecosystem CO2 uptake differentially across high-Arctic tundra habitats.

Environmental changes, such as climate warming and higher herbivory pressure, are altering the carbon balance of Arctic ecosystems; yet, how these drivers modify the carbon balance among different habitats remains uncertain. This hampers our ability to predict changes in the carbon sink strength of tundra ecosystems. We investigated how spring goose grubbing and summer warming-two key environmental-change drivers in the Arctic-alter CO2 fluxes in three tundra habitats varying in soil moisture and plant-community composition. In a full-factorial experiment in high-Arctic Svalbard, we simulated grubbing and warming over two years and determined summer net ecosystem exchange (NEE) alongside its components: gross ecosystem productivity (GEP) and ecosystem respiration (ER). After two years, we found net CO2 uptake to be suppressed by both drivers depending on habitat. CO2 uptake was reduced by warming in mesic habitats, by warming and grubbing in moist habitats, and by grubbing in wet habitats. In mesic habitats, warming stimulated ER (+75%) more than GEP (+30%), leading to a 7.5-fold increase in their CO2 source strength. In moist habitats, grubbing decreased GEP and ER by ~55%, while warming increased them by ~35%, with no changes in summer-long NEE. Nevertheless, grubbing offset peak summer CO2 uptake and warming led to a twofold increase in late summer CO2 source strength. In wet habitats, grubbing reduced GEP (-40%) more than ER (-30%), weakening their CO2 sink strength by 70%. One-year CO2-flux responses were similar to two-year responses, and the effect of simulated grubbing was consistent with that of natural grubbing. CO2-flux rates were positively related to aboveground net primary productivity and temperature. Net ecosystem CO2 uptake started occurring above ~70% soil moisture content, primarily due to a decline in ER. Herein, we reveal that key environmental-change drivers-goose grubbing by decreasing GEP more than ER and warming by enhancing ER more than GEP-consistently suppress net tundra CO2 uptake, although their relative strength differs among habitats. By identifying how and where grubbing and higher temperatures alter CO2 fluxes across the heterogeneous Arctic landscape, our results have implications for predicting the tundra carbon balance under increasing numbers of geese in a warmer Arctic.

Drought Index Assessment Using Thermal Vegetation Index (TVI) Method and Soil Physic Approaches (A Case study: Manyaran District, Central Java, Indonesia)

The early detection of areas that have the potential to experience drought is necessary to minimize the hazards of land drought. The study aimed to identify the current conditions of drought by TVI with actual soil physic characteristic approaches, and to find the determinant factors related to the dynamics of agricultural land drought conditions so as to determine land management strategies that are considered appropriate and efficient to prevent agricultural land drought. The method for analyzing the drought index was the Thermal Vegetation Index (TVI) method, which involved the calculation of the ratio between the Land Surface Temperature (LST) and the vegetation index using Normalized Difference Vegetation Index (NDVI). The method in this research was modified by adding soil physical indicators, including soil moisture content, bulk density, and pF value. The results showed that the land drought classes were normal drought (46.89% study area), mild drought (20.62% study area), moderate drought (14.10% study area), severe drought (8.58% study area), and extreme drought (9.81% study area). Land drought was highly correlated to the soil's physical condition, negatively correlated with the moisture content (r -0.403) and bulk density (r -0.317), and positively correlated with the pF (r 0.429). Enhancing the soil’s capacity to absorb water and retain moisture through the addition of organic matter is one of the required techniques as a suitable recommendation to the issue after determining the determinant factors and present conditions.

Effect of altitude on soil physico-chemical properties and microbial biomass carbon in the Eaglenest Wildlife Sanctuary of Arunachal Pradesh

ABSTRACT The present study focuses on the variation in soil properties and microbial biomass carbon along an elevation gradient in the Eaglenest Wildlife Sanctuary, Arunachal Pradesh. Soil was acidic in nature and pH value ranges from 4.37 ± 0.14 to 5.25 ± 0.29. Soil texture varied from sandy to loamy sand. Clay content and available potassium showed a significant negative correlation (p < 0.05) with altitude. Water holding capacity and available nitrogen showed a strongly significant positive correlation (p < 0.01). Soil bulk density, temperature, moisture content, pH, available phosphorus and microbial biomass carbon showed a strongly significant negative correlation (p < 0.01) with altitude. Soil organic carbon stock was highest (66.39 ± 9.36 t h−1) in tropical zone and lowest (44.33 ± 6.34 t h−1) in temperate zone. Higher soil organic carbon and organic matter (4.16 ± 0.58% and 7.17 ± 1.00%) were found in subtropical zone while lowest (2.57 ± 0.38% and 4.42 ± 0.64%) were found in tropical zone. Available nitrogen and available potassium were highest (604.10 ± 24.13 kg h−1 and 418.14 ± 26.53 kg h−1) in subtropical zone and lowest available potassium (282.82 kg h−1 ± 14.68 kg h−1) was recorded in the temperate zone. Higher available phosphorous (62.51 ± 6.96 kg h−1) was recorded in tropical zone while lowest (10.66 ± 1.49 kg h−1) was recorded in the subtropical zone. The first four main components of the principal component analysis jointly explained 78.51% of the overall variation. The results from the principal component analysis align closely with Pearson’s correlation analysis and analysis of variance, reinforcing the accuracy and reliability of the observed trends in data. The present study clearly indicates that altitudinal variation exerts a significant effect on the soil’s physico-chemical properties. It suggests that understanding the effects of altitudinal variation on soil properties is important for the establishment and restoration of the vegetation in diverse altitudinal zone.

Comparative Study of Water and Fertilizer Regimes on Water Potential, Phenolic Substances, and Photosynthetic Characteristics of Pistacia weinmannifolia

Effective water and fertilizer management is crucial for the forestry production of Pistacia weinmannifolia. This experiment employed an orthogonal design to measure the water potential, anthocyanins, chlorophyll, and photosynthetic parameters of Pistacia weinmannifolia under different water and fertilizer regimes. The effects of different water and fertilizer regimes on the water potential, phenolic compounds, and photosynthetic characteristics of Pistacia weinmannifolia were analyzed. A comprehensive analysis method was used to evaluate and establish the best water and fertilizer regimes system. The results showed that the water and fertilizer regimes increased the water potential, anthocyanins, chlorophyll content, flavonoids, and photosynthesis (p &lt; 0.05). During the mid-growth stage and late mid-stage growth of Pistacia weinmannifolia, the fertilizers with the most significant effects on water potential, chlorophyll, and anthocyanins were nitrogen (N) and phosphorus (P). The supply of a certain amount of N and P had positive effect on water potential, chlorophyll, and anthocyanins. Increasing N content was more effective in improving carboxylation efficiency than increasing P content. The effect of N content on photosynthetic efficiency was greater than that of P content Analyses using the TOPSIS model demonstrate that Pistacia weinmannifolia exhibits superior comprehensive efficiency in water potential, chlorophyll, flavonoid, and anthocyanin content. When applying 0.54 g·plant−1 of pure P and 0.67 g·plant−1 of pure N, with the relative soil moisture content maintained at 85%, the optimal comprehensive benefit for photosynthetic indicators is achieved with 0.34 g·plant−1 of pure P and 0.77 g·plant−1 of pure N, while maintaining the relative soil moisture content at 46.66%. These findings indicate that the water–fertilizer coupling treatment group exhibited improved growth status and photosynthesis. Therefore, the cultivation of Pistacia weinmannifolia should prioritize maintaining a balanced water–fertilizer ratio to optimize resource utilization.

Recognizing and reducing effects of moisture-salt coexistence on soil organic matter spectral prediction：From laboratory to satellite

Soil organic matter (SOM) mapping in salinized areas is crucial for scientific guidance on soil salinization. However, accurately mapping SOM is challenging due to the intricate interplay between soil moisture content (SMC) and soil salt content (SSC), which significantly influences soil spectra. Unlike prior research that has separately examined the impacts of moisture or salinity, this study delves into the combined effects of these factors on SOM spectra. The objective of this study is to develop and validate several spectral optimization algorithms at both the laboratory and satellite levels. In October 2020, a study was conducted using 291 ground-truth data to examine the impact of various moisture-salt stages (seven moisture stages, five salt stages) on hyperspectral data. Spectrum mechanism responsive for soil moisture and salinity were analyzed through spectral curves, correlation, and analysis of variance (Anova, AOV), and spectrum mechanism responsive for soil moisture and salinity model were built. Following that, the spectra were optimized using piecewise direct normalization (PDS)-AOV, non-negative matrix factorization (NMF)-AOV, and orthogonal signal correction (OSC)-AOV. The SOM prediction models were then built by integrating these optimized spectra with Stacking ensemble machine learning algorithms (RF, GBM, ANN). Eventually, the lab-optimized spectra were merged with satellite multispectral images to create new image (named REC) for SOM mapping. The results indicated varying impacts of SMC and SSC on spectra, particularly between 1400 nm to 2000 nm, revealing the influence of moisture-salt interaction; the best optimization algorithm (OSC-AOV) with Stacking mitigated the effect of moisture-salt coexistence on spectra (the R2 and RPD of the best models elevated by 0.005–0.267, 0.020–0.374 respectively, RMSE reduced by 0.137–1.817 g/kg); implementing this algorithm on REC significantly improved the accuracy of SOM mapping (R2 elevated by 0.185–0.259, RMSE reduced by 2.615–3.203 g/kg). This study extensively investigated the effects of moisture and salinity on spectra, spanning from laboratory to satellite, offering a novel approach to understanding and addressing the complexities in SOM mapping in salinized environments.

Enhanced soil stabilisation and growth of Lolium perenne through combined seeding with Cynodon dactylon

Herbaceous plants play a crucial role in soil stabilisation, and combined seeding is often employed in ecosystem management to promote biodiversity. This study investigated the influence of combined seeding of Ryegrass (Lolium perenne) and Bermuda (Cynodon dactylon) on plant growth and soil stabilisation through in-situ sampling and indoor experimental measurements. Four experimental plots were established: a. bare soil, b. L. perenne single species, c. C. dactylon single species, d. combined L. perenne and C. dactylon. The results indicate that combined seeding inhibited the development of L. perenne and C. dactylon root depth by 14.50% and 29.20%, respectively. However, shoot height, total leaf area, total root length and total root surface area increased in L. perenne under combined seeding, while these parameters decreased for C. dactylon. Combined seeding significantly enhanced the resistance to breakage in tension and tensile strength of L. perenne, with no significant impact on C. dactylon. Plant roots notably increased soil cohesion, with a respective increase of 37.08%, 26.98%, and 50.81% in cohesion for L. perenne single species plot, C. dactylon single species plot, and combined L. perenne and C. dactylon plot compared to bare soil. The root content in combined seeding significantly increased, with an increase of 27.17% and 65.20% compared to single seeding of L. perenne and C. dactylon, respectively. Additionally, under the influence of roots, the soil moisture content in the combined seeding plot was lower than in the single species and bare soil plots. These findings highlight that combined seeding enhanced plant competition, improved soil shear strength, and provided significant ecological benefits, offering insights for vegetation-based slope design.

Impact of labour saving techniques on soil moisture content, weed dynamics and pink bollworm incidence in Bt cotton

Impact of labour saving techniques on soil moisture content, weed dynamics and pink bollworm incidence in Bt cotton

Effect of temperature and moisture on soil pathogen Fusarium solani of lemon in Adjara, Georgia

The research was conducted in the 2022 and 2023 seasons in the agrometerology and plant protection laboratory and citrus greenhouse of Batumi Shota Rustaveli State University, the aim of which was groupe and unit role of temperature and soil moisture (SM) content on aggressive soil pathogen F. solani on lemon, also effects of pathogen density and soil moisture on belowground and aboveground morphological traits. In our study, we could find that the both temperature and soil moisture played a decisive role in influencing the root rot disease scenario. As per the disease susceptibility index (DSI), a combination of high temperature (35°C) and low SM (60%) was found to elicit the highest disease susceptibility in lemon. High pathogen colonization was realized in lemon root tissue at all time-points irrespective of genotype, temperature, and SM. Interestingly, this was in contrast to the DSI where no visible symptoms were recorded in the roots or foliage during the initial time-points. For each time-point, the colonization was slightly higher at 35°C than 25°C, while the same did not vary significantly with respect to SM. Shoot biomass was not affected by either pathogen density or soil moisture. However, the two experimental factors have additive effects on the severity of leaf damage. Leaf damage increased with the density of F. solani in the soil, being significantly higher at 60 CFU/g and 120 CFU/g than in control seedlings. Leaf damage was higher at the two extreme soil moisture levels (15% and 100% WHC) than at the two intermediate levels (40% and 50%). In addition, differential expression studies revealed the involvement of defense-related genes, such as endochitinase and chitinase, in the resistant lemon cultivar Meyer, which contribute to retarding root rot disease progression in lemon. In the early stages of infection, especially with low SM. That can be beneficial for farmers and researchers who involve in Citrus

Determination of irrigation standards for winter wheat through monitoring of groundwater levels

Abstract This article presents field experiments widely used in the irrigation of winter wheat, monitoring the groundwater level. Data indicate that groundwater use in the Republic of Uzbekistan increases by 23-25 km³ per year. There is also the possibility for widespread use of groundwater to irrigate land plots with close groundwater levels and mineralization between 1 and 3 g/L in the Syrdarya region. During the study, an experimental field was divided into 16 small areas and processed four times on each one. Groundwater was artificially raised to depths of 1.0 and 2.0 meters, blocking closed horizontal drainage. According to the results, during the non-growing season, closed horizontal drainage blocked at a height of 0.1 m, groundwater levels were 27.2-29.8 cm. In the version with overlap at 2 meters - 28.9-31.1 cm, and in the control - 31.4-32.5 cm. During the growing season, when the closed horizontal drainage is blocked at a height of up to 1.0 cm, the groundwater level is 286-288 cm. In the variant where groundwater is blocked to a height of 2.0 m, the ground water level is 270-304 cm, allowing the use of ground water to increase the capillary moisture content of soil when watering winter wheat during low water years.

The Dynamic Characteristics and Influencing Factors of Soil Respiration in Different Types of Grasslands in the Barkol Lake Basin

Determining regional and global carbon cycles hinges on investigating the dynamic characteristics and influencing factors of soil respiration in various types of natural grasslands located in arid regions, and these characteristics are important indicators for assessing the structural and functional health of grassland ecosystems. Such investigations also provide theoretical support for carbon sink monitoring, energy conservation, emission reduction and low-carbon development in the western arid zone and are important for obtaining an in-depth understanding of the carbon cycle, as well as for ecosystem management, restoration and the reconstruction of arid areas. In this study, during the growing season (from May to October) of 2022, the LI-8100A automated soil CO2 flux system was used to measure the soil respiration rate (Rs), temperature from 1.5 m above the surface to depths of 5–25 cm (T, T5, T10, T15, T20 and T25) and the soil moisture content (SM) at a depth of 20 cm in four types of grasslands: lowland meadow, alpine meadow, temperate desert steppe and temperate steppe desert. Five replicates were established for each plot, and the responses of Rs to T and SM were fitted to construct the optimal regression model. The results revealed that (1) the daily average soil respiration was highest in the lowland meadow (0.07 to 5.76 μmol·m−2·s−1), followed by the alpine meadow (−0.57 to 0.95 μmol·m−2·s−1), the temperate desert steppe (−0.45 to 3.0 μmol·m−2·s−1) and the temperate steppe desert (−1.29 to 1.61 μmol·m−2·s−1); (2) the soil respiration rates of the four grassland types were significantly correlated with the temperature in the 5–15 cm soil layer, and the best model was an exponential function; the peak values generally appeared between 13:00 and 17:00 (h), with the minimum values at 2:00 or 8:00 (h); the maximum value was observed in July–August, and the minimum value was observed in October; and the soil respiration in the lowland meadow was higher than that in the other three types of grassland during the same period. The average variation intensities of the soil respiration from May to October were as follows: temperate steppe desert (91.78%) &gt; temperate desert steppe (76%) &gt; alpine meadow (58.77%) &gt; lowland meadow (43.93%). (3) The partial correlation analysis revealed that when soil temperature was used as a control, the correlation between SM and soil respiration in the four types of grasslands changed, and the coefficient of determination (R2) increased to varying degrees, explaining up to 80% of the variation in the soil respiration in the lowland meadows. The correlation between soil respiration and the SM normalized to 10 °C explained up to 93.8% of the variation in soil respiration; the two-factor fitting equations revealed that the model with soil temperature and SM was superior to the single-factor model with either soil temperature or SM.

Nonstationary linkage between summer warmth index and NDVI at high latitudes in Eurasia

Abstract The global increase in vegetation photosynthetic activity under the warming climate, commonly referred to as “greening”, has been a hot topic, especially in the high latitudes. However, in this study, it was found that, within the region of 60°–70°N and 110°–150°E, the interannual relationship between summer NDVI (normalized difference vegetation index) and SWI (summer warmth index) changes from being statistically positive in P1 (1982–2010) to statistically negative in P2 (2011–2021). Also, the interannual relationship between summer NDVI and summer soil moisture changes from being negative in P1 to positive in P2. The reason and possible mechanisms were investigated. On the one hand, the atmospheric vapor pressure deficit (VPD) has increased significantly in P2 corresponding to the increasing SWI, and the interannual relationship between the VPD and NDVI transforms into a significantly negative one. This is because, when the atmospheric VPD increases, leaf and canopy photosynthetic rates decline owing to stomatal closure, to protect vegetation from losing too much water. Therefore, the interannual relationship between the NDVI and VPD, and in turn the SWI, transforms into a significantly negative one in P2. On the other hand, it was found that the surface evapotranspiration is energy-limited in P1, but then with the decreasing soil moisture content it becomes soil-moisture-limited in P2. As one of the most important components of surface evapotranspiration, vegetation evapotranspiration is also limited by soil moisture. Therefore, the interannual relationship between soil moisture and NDVI becomes significantly positive in P2.

Effects of Pulsed Electric Fields on the Elimination of Fusarium oxysporum in Greenhouse Soil

In greenhouses, high humidity, low light, and inadequate ventilation conditions, along with continuous and high-density planting, promote the proliferation of soilborne pathogens. Among these pathogens, Fusarium oxysporum Schltdl (F. oxysporum) is a notably challenging one, causing root rot of tomato plants in greenhouse cultivation. To address this issue, this study applied a pulsed electric field (PEF) to target the elimination of F. oxysporum in suspension and soil media. Initially, PEF parameters were systematically explored in suspensions to determine the effective ranges for the elimination of F. oxysporum. The results revealed that the effective ranges for achieving the desired microbial reduction were an electric field strength (EFS) between 5–15 kV·cm−1, a pulse number within the range of 100–500, and a pulse width of 10–20 µs. Subsequently, the impact of soil moisture content, soil bulk density, and soil type on soil dielectric breakdown field strength was analyzed within the range from previous results. Based on these findings, the soil experiments were conducted with parameters designed to prevent dielectric breakdown. Specifically, for sampling soil with a moisture content of 16.2% and a bulk density of 1.31 g·cm−3, the maximum effective application of electric field strength was 9.5 kV·cm−1, accompanied by 1000 pulses and a pulse width of 20 µs. Finally, building on these results, soil samples were sterilized within a parameter range that spanned an electric field strength of 5–9.5 kV·cm−1, a pulse number between 100–500, and a pulse width of 10–20 µs. Response surface methodology (RSM) analysis further identified the optimal parameter combination: an electric field strength of 8.2 kV·cm−1, 306 pulses, and a pulse width of 15 µs, resulting in an average lethal rate of 76.16% for F. oxysporum sterilization in soil. These findings suggest the potential use of PEF against F. oxysporum and other pathogens in greenhouse soils, and provide theoretical foundations for further experiments, thereby contributing to the sustainable advancement of greenhouse agriculture.

Spatial distribution of soil pore structure and response characteristics of physical parameters in the subsidence area induced by shallow-buried extra-thick coal seam mining

The development of ground fissures in the subsidence area induced by shallow-buried extra-thick coal seam mining leads to a decrease in soil water-holding capacity and vegetation withering. The investigation of the spatial distribution characteristics of soil pore structure in mining-induced subsidence areas and the elucidation of the response mechanism between soil physical parameters and soil structure are essential prerequisites for achieving effective ecological environment protection and restoration in mining areas. In this study, three-dimensional visualization reconstruction of soil porosity, pore diameter, roundness rate and pore connectivity at different profile depths in subsidence area caused by ultra-thick coal seam mining was conducted by using the soil CT scanning technology. Additionally, a correlation analysis model was established between physical parameters such as soil moisture content, bulk density, and pore structure parameters. The results indicate that: (1) Compared to the non-subsidence area, the number, size, and proportion of soil pores significantly increase in the tension zone, compression zone, and neutral zone, and the pore network and connectivity are extensively interconnected, and the fissure development in the tension zone is most significant, and the soil pores in the subsidence compression zone are concentrated on one side due to the influence of soil deformation. (2) As the depth of the soil profile increases, the level of soil pore development significantly decreases. The large profile depth (40–100 cm) causes a significant decrease in pore development. (3) There is a significant correlation between soil pore structure parameters and soil physical parameters (P ≤ 0.05), a highly significant correlation between soil pore structure parameters and soil moisture content (P ≤ 0.01), and a highly significant correlation between soil texture and soil moisture content (P ≤ 0.01). This research is of great significance for guiding underground production layout and repairing damaged soil.

Evaluation of Land Surface Management on Moisture Conservation, Yield and Yield Components of Maize (&amp;lt;i&amp;gt;Zea Mays &amp;lt;/i&amp;gt;L.) in East Shewa Zone of Oromia, Ethiopia

Maize is an important food crop in Ethiopia and it is one of the main smallholder food crops in the rift valley of Oromia, although shortage of rainfall and erratic occurrence was caused soil moisture content stressed yields reduced. Suitable soil and water conservation measures that can be easily integrated into the existing farming operations while enhancing in-situ moisture conservation. The study was conducted on land surface management to increase soil moisture content, amend soil nutrients and enhance yield and yield components of maize. The experiment was conducted during the 2021 and 2022 main cropping seasons at Adami Tulu Agricultural Research Center on-station using RCBD that had five tested treatments. Maize variety Melkasa-II was used as a testing crop for its familiar to local communities. The results indicated that soil moisture content was enhanced by 5.8% to 26.4% in maturity and vegetative stages up to 60 cm depths. Soil physico-chemical properties were improved and the highest grain yield was obtained from 5 tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; (SM+FYM) plus NPS fertilizer and 5 tha&amp;lt;sup&amp;gt;-1&amp;lt;/sup&amp;gt; of straw mulch plus inorganic fertilizers treatments that increased by three to four fold of the organic fertilizer applied and control treatments orderly. This result implies that retaining crop straw mulch and application of farmyard manure in the field within profitable cost can be used as soil moisture conservation tool for sustainable improvement of maize production in the study area.

Climate Change and Human Activities Contribute to the Enhancement Recovery of Grassland Productivity in Xinjiang

ABSTRACTGrasslands, as a vital component of arid and semi‐arid terrestrial ecosystems, play a pivotal role in carbon cycling and ecosystem functioning. Climate change and human activities significantly affected grassland productivity. Understanding the main driving factors and their contribution rates is of great significance for the protection and sustainable development of grasslands. However, we still lack a comprehensive understanding of the changes in grassland productivity and their driving factors in Xinjiang. This study investigated the spatiotemporal characteristics and underlying driving factors of grassland actual net primary productivity (AcNPP) in Xinjiang from 2000 to 2022, utilising the Carnegie‐Ames‐Stanford Approach and geospatial detectors. Employing the nonlinear Random Forest technique, we assessed the dual impacts of climate change and human activities on grassland productivity. Our findings revealed that grassland productivity in Xinjiang exhibited fluctuating growth during this period, with an average annual AcNPP growth rate of 0.33 g C m−2 year−1. Comprehensive evaluation revealed that soil type, precipitation, and soil moisture content were the key determinants of the spatial distribution of AcNPP, with higher values in mountainous regions and lower in basins. The study further revealed that climate change, human activities, and their combined effects contributed to the recovery of 60.97% of grasslands in Xinjiang. However, human activities were the primary drivers of grassland degradation, with a contribution rate reaching 67.71%. Further analysis indicated that water conditions, particularly precipitation and soil moisture content, were the main forces driving grassland changes in Xinjiang. Although grazing management strategies, such as rotational stocking and deferred stocking, facilitated grassland recovery in 36.71% of areas impacted by human activities, grazing remains a significant anthropogenic factor contributing to grassland degradation. These findings provide valuable scientific insights for the effective management and conservation of Xinjiang's grassland ecosystems.

Plant Diversity, Productivity, and Soil Nutrient Responses to Different Grassland Degradation Levels in Hulunbuir, China

Grassland degradation could affect the composition, structure, and ecological function of plant communities and threaten the stability of their ecosystems. It is essential to accurately evaluate grassland degradation and elucidate its impacts on the vegetation–soil relationship. In this study, remote sensing data based on vegetation coverage were used to assess the degradation status of Hulunbuir grassland, and five different grassland degradation degrees were classified. Vegetation community composition, diversity, biomass, soil nutrient status, and their relationships in different degraded grasslands were investigated using field survey data. The results showed that grassland degradation significantly affected the species composition of the vegetation community. As degradation intensified, species richness declined, with the proportion of Gramineae and Legume species decreasing and Asteraceae species increasing. Additionally, the proportion of annual species initially increased and then decreased. Degradation also markedly reduced aboveground, belowground, and litter biomass within the communities. Soil moisture, electrical conductivity, organic carbon, total carbon, total potassium, and hydrolyzable nitrogen contents in non-degraded areas were higher than those in severely degraded areas. Conversely, soil total phosphorus content and bulk density gradually increased with degradation. Nitrate nitrogen and ammonium nitrogen levels in severely degraded soils were significantly higher than those in non-degraded soils. Plant diversity in the study area was significantly positively correlated with aboveground biomass and belowground biomass, and it positively correlated with soil nutrient total carbon and available carbon but negatively correlated with soil bulk density. Results of the partial least squares path model showed that grassland degradation had significant negative effects on plant diversity, soil nutrients, and biomass. Soil nutrients were the main factors affecting ecosystem productivity. The direct effect of plant diversity on biomass was not significant, suggesting that soil nutrients may play a more important role than plant diversity in determining biomass during grassland degradation. The results illustrated the relationships among soil nutrients, plant diversity, and biomass in degraded grasslands and emphasized the importance of an integrated approach in the effective management and restoration of degraded grasslands.