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Abstract\nNOVELTY STATEMENTPlants face numerous environmental challenges from biotic and abiotic stressors, with soil salinization emerging as a significant global concern. The coastal regions of Tamil Nadu, face severe environmental challenges due to discharge of saline water from shrimp farms exacerbates this issue, compromising the viability of paddy and other crops in the vicinity. This study explores the phytoremediation potential of Suaeda fruticosa in addressing soil salinity resulting from shrimp farming activities under field conditions over a 120-day period to restore soil health in salt affected soil. This research demonstrates Suaeda fruticosa’s exceptional salt tolerance and bioaccumulation potential in facilitating soil restoration. Significant enhancements were observed in various growth parameters, including 466% increase in plant height, 338% in fresh weight and 387% in dry weight. Biochemical parameters also showed substantial enhancements with total chlorophyll, protein, proline, phenol, and glycinebetaine levels increasing by 655%, 588%, 690%, 153%, and 531%, respectively. Enzymatic activities exhibited notable elevations as well, with catalase, peroxidase, and polyphenol oxidase activities escalating by 258%, 587%, and 121% respectively, indicating robust adaptation to saline environments. Moreover, Suaeda fruticosa exhibited remarkable bioaccumulation capabilities, accumulating 461 kg NaCl ha−1. This led to substantial improvements in soil characteristics, including a reduction in pH from 8.8 to 6.49, electrical conductivity from 5.7 to 1.53 dSm−1, and sodium adsorption ratio from 16.1 to 4.4 mmol L−1. The successive cultivation of Suaeda fruticosa in this study, has proven to be a viable strategy for reclaiming salt-affected lands, thereby alleviating a significant constraint on crop productivity.In this phytoremediation study, Suaeda fruticosa can effectively bioaccumulate considerable amounts of NaCl from the soil, leading to marked improvements in soil quality. This includes reductions in soil pH, electrical conductivity, and sodium adsorption ratio. A salt marsh halophyte, Suaeda fruticosa not only accumulates salt but also adapts to such conditions by synthesizing substantial amounts of organic solutes and enhancing its antioxidant machinery to mitigate toxicity induced by ionic stress. This research underscores a promising and sustainable approach for the reclamation of saline-affected agricultural soils, offering a viable solution to enhance crop productivity in coastal regions impacted by shrimp aquaculture. [ABSTRACT FROM AUTHOR]

Effective management of agricultural water resources in arid regions relies on precise estimation of irrigation-water demand. Most previous studies have adopted pixel-level mapping methods to estimate irrigation-water demand, often leading to inaccuracies when applied in arid areas where land salinization is severe and where poorly growing crops cause the growing area to be smaller than the sown area. To address this issue and improve the accuracy of irrigation-water demand estimation, this study utilizes parcel-aggregated cropping structure mapping. We conducted a case study in the Weigan River Basin, Xinjiang, China. Deep learning techniques, the Richer Convolutional Features model, and the bilayer Long Short-Term Memory model were applied to extract parcel-aggregated cropping structures. By analyzing the cropping patterns, we estimated the irrigation-water demand and calculated the supply using statistical data and the water balance approach. The results indicated that in 2020, the cultivated area in the Weigan River Basin was 5.29 × 105 hectares, distributed over 853,404 parcels with an average size of 6202 m2. Based on the parcel-aggregated cropping structure, the estimated irrigation-water demand ranges from 25.1 × 108 m3 to 30.0 × 108 m3, representing a 5.57% increase compared to the pixel-level estimates. This increase highlights the effectiveness of the parcel-aggregated cropping structure in capturing the actual irrigation-water requirements, particularly in areas with severe soil salinization and patchy crop growth. The supply was calculated at 24.4 × 108 m3 according to the water balance approach, resulting in a minimal water deficit of 0.64 × 108 m3, underscoring the challenges in managing agricultural water resources in arid regions. Overall, the use of parcel-aggregated cropping structure mapping addresses the issue of irrigation-water demand underestimation associated with pixel-level mapping in arid regions. This study provides a methodological framework for efficient agricultural water resource management and sustainable development in arid regions. [ABSTRACT FROM AUTHOR]

Soil salinization has been considered as a major environmental threat to plant growth. Different types of salt in saline soil have different effects on germination and seedling growth. Effect of NaCl on germination and seedling establishment in Suaeda liaotungensis have been reported, but its response to alkali stress remains unclear. Our results showed that brown seeds had higher germination rate, however, black seeds had higher germination recovery percentage under alkali stress. Na2CO3 had stronger inhibitory effect on germination and seedling growth than NaHCO3. As the concentration of alkali stress increased, the ROS level of brown seeds gradually ascended, while that of black seeds decreased first and then ascended. MDA content of dimorphic seeds significantly increased under alkali stress. The trend of SOD, POD and CAT activity between dimorphic seeds was similar under the same type of alkali stress. Alkali stress enhanced proline content of dimorphic seeds, and dimorphic seeds in NaHCO3 solution had higher proline content than Na2CO3 solution. Moreover, radicle and shoot tolerance indexes of seedlings in NaHCO3 solution were significantly higher than that of Na2CO3 solution. Under strong alkali stress, seedlings in NaHCO3 solution had significantly lower ROS level and MDA content as well as higher antioxidant enzyme activity than Na2CO3 solution. This study comprehensively compared the morphological and physiological characteristics in germination and seedlings to better reveal the saline-alkali tolerance mechanisms in S. liaotungensis. [ABSTRACT FROM AUTHOR]

SUMMARY: Alfalfa is one of the most widely cultivated forage crops worldwide. However, soil salinization restricts alfalfa growth and development and affects global productivity. The plant cell wall is the first barrier against various stresses. Therefore, elucidating the alterations in cell wall architecture is crucial for stress adaptation. This study aimed to clarify the impact of myo‐inositol oxygenase 2 (MsMIOX2) on cell wall pectin and hemicellulose biosynthesis under saline–alkali stress and identify the upstream transcription factors that govern MsMIOX2. MsMIOX2 activation induced cell wall pectin and hemicellulose accumulation under saline–alkali stress. The effects of MsMIOX2 in saline–alkali tolerance were investigated by characterizing its overexpression and RNA interference lines. MsMIOX2 overexpression positively regulated the antioxidant system and photosynthesis in alfalfa under saline–alkali stress. MsMIOX2 exhibited myo‐inositol oxygenase activity, which increased polysaccharide contents, facilitated pectin and hemicellulose biosynthesis, and extended the cell wall thickness. However, MsMIOX2 RNA interference decreased cell wall thickness and alleviated alfalfa saline–alkali stress tolerance. In addition, MsbZIP53 was identified as an upstream transcriptional MsMIOX2 regulator by yeast one‐hybrid, electrophoretic mobility shift assay, dual‐luciferase, and beta‐glucuronidase assays. MsbZIP53 overexpression increased MsMIOX2 expression, elevated MIOX activity, reinforced the antioxidant system and photosynthesis, and increased saline–alkali stress tolerance in alfalfa. In conclusion, this study presents a novel perspective for elucidating the molecular mechanisms of saline–alkali stress tolerance in alfalfa and emphasizes the potential use of MsMIOX2 in alfalfa breeding. [ABSTRACT FROM AUTHOR]

Ashes from biomass combustion (BAs) are a valuable source of plant nutrients, making them suitable for fertilizing crops. BAs also contain components that directly affect soil environmental conditions, leading to improved growth and development of plants. Their deacidifying properties allow BAs to serve as a substitute for calcium fertilizers. However, they contain substantial amounts of components that can increase soil salinity, which can have negative effects. The aim of this study was to assess the impact of BAs on changes in pH and salinity of haplicluvisol soil under the cultivation of various plant species. The study also analyzed the effects of BAs on the content of total forms of calcium (Ca), magnesium (Mg), potassium (K), and sodium (Na) in the soil. The BAs used in the experiment were sourced from a combined heat and power plant that combusts forest and agricultural biomass. These BAs are distributed as a product for fertilizing agricultural land. However, their application is not subjected to further monitoring. The results indicated that the application of different doses of BAs significantly affected the pH of the analyzed soil. Compared to control objects, a significant increase in pH was observed, with these changes dependent on the species of the cultivated plant. Additionally, even the smallest doses of BAs caused an increase in the electrolytic conductivity (EC) of soil solutions, which serves as a measure of soil salinity. Despite the increase in the average EC value, the application of BAs did not alter the salinity class. The use of BAs also significantly influenced other analyzed parameters. An increase in the average content of total forms of Ca, Mg, K, and Na in the soil was observed, along with a higher degree of soil saturation with alkaline cations, compared to the control and the soil condition before the experiment. The changes in the analyzed soil parameters were significantly influenced not only by the different doses of BAs but also by the species of the cultivated plant. The greatest fluctuations in the obtained values were observed in soil under winter rape cultivation, while the smallest fluctuations were noted in soil under spring barley and potato cultivation. [ABSTRACT FROM AUTHOR]

The continuous global escalation of soil salinization areas presents severe challenges to the stability and growth of agricultural development across the world. In-depth research on sugar beet (Beta vulgaris L.), an important economic and sugar crop with salt tolerance characteristics, is crucial for to determine its salt-tolerance mechanisms, which has important practical implications for production. This review summarizes the multifaceted effects of salt stress on sugar beet, ranging from individual plant responses to cellular and molecular adaptations. Sugar beet exhibits robust salt-tolerance mechanisms, including osmotic regulation, ion balance management, and the compartmentalization of toxic ions. Omics technologies, including genomics, transcriptomics, proteomics, post-translational modification omics and metabolomics, have played crucial roles in elucidating these mechanisms. Key genes and pathways involved in salt tolerance in sugar beet have been identified, paving the way for targeted breeding strategies and biotechnological advancements. Understanding these mechanisms not only enhances our knowledge of sugar beet's adaptation strategies but also provides insights for improving salt tolerance in other crops. Future studies should focus on analyzing gene expression changes in sugar beet under salt stress to gain insight into the molecular aspects of its salt-tolerance mechanisms. Meanwhile, the effects of different environmental conditions on sugar beet adaptation strategies should also be investigated to improve their growth potential in salinized soils. [ABSTRACT FROM AUTHOR]

The El Haouz and El Kelaa Des Sraghna region is renowned for its agriculture, but is facing problems of salinisation due to its arid climate and unfavourable weather conditions. To remedy this, localised irrigation systems have been introduced to provide water for crops and improve yields. This study examines the impact of these irrigation systems on soil salinity in the region by comparing upstream and downstream areas. Using remote sensing techniques, we identify areas at risk of high salinity and collect soil samples for physical and chemical analysis in the field. These analyses enable us to monitor changes in salinisation and assess the effectiveness of localised irrigation in the areas concerned. Our results reveal two distinct zones in the region: an upstream zone with low salinity, with electrical conductivity ranging from 66 µS/cm to 345 µS/cm, and a downstream zone with higher salinity, with electrical conductivity ranging from 228 µS/cm to 1.075 µS/cm, attributed to the use of localised irrigation for crops. The remote sensing maps anticipated this difference, which was confirmed by the field analyses. [ABSTRACT FROM AUTHOR]

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Soil salinization poses a significant ecological challenge, emerging as a critical constraint to agricultural development in the arid and semi-arid regions of China, especially in southern Xinjiang. In particular, Yuepuhu County, situated in Kashgar, faces a distinctive issue. Impermeable thin clay layers within the vadose zone impede year-round leaching of salts, significantly impacting the growth of cotton. Through a combination of indoor testing, experiments, and statistical analyses, this study elucidated the varying permeability of soil layers at different depths and explored the forms and accumulation characteristics of soil salts in Yuepuhu County. It unveiled patterns of water and salt movement in soils with variable permeability layers, identifying key influencing factors. The research also proposed an irrigation regime suitable for cultivating vadose zone soils in the local context. The findings revealed a progression of increasing soil complexity and decreasing burial depth of clay layers from northwest to southeast, aligned with the direction of groundwater flow. With increasing depth, a noticeable reduction in soil saturated hydraulic conductivity was observed, indicating significant variability in permeability. Predominantly chloride-sulfate type saline soils in Yuepuhu County contained potassium (K+) and sodium (Na+) as the main cations in surface soils. Salinity strongly correlated with calcium (Ca2+) and magnesium (Mg2+). Chloride (Cl−), sulfate (SO42−), K+, Na+, and bicarbonate (HCO3−) reflected the degree of soil salinization in Yuepuhu County. The clay interlayers in variable permeability zones significantly impeded water and salt movement in the vadose zone. Moving from west to east, thicker and shallower clay interlayers hindered downward water movement, increasing the difficulty of salt leaching. Additionally, the irrigation regime influenced water and salt movement in the vadose zone. Under the same soil structure, flood irrigation with a higher water flux resulted in more significant salt leaching, and lower total dissolved solids (TDS) in irrigation water were more favorable for effective salt leaching. Collectively, our findings provided a theoretical foundation for improving and managing local saline soils, as well as guiding the implementation of rational agricultural irrigation practices. [ABSTRACT FROM AUTHOR]

Coal mining in arid and semiarid regions often leads to numerous ecological and environmental problems, such as aquifer depletion, lake shrinkage, vegetation degradation, and surface desertification. The drainage from coal mining activities is a major driving force in the evolution of the groundwater-soil-vegetation system. In order to explore the effect of groundwater level fluctuation on soil properties and the response mechanism of surface vegetation in coal mining areas, this study is based on hydrogeological and ecological vegetation investigations in the Bojianghaizi Basin, and soil and vegetation samples are collected in the areas with different groundwater levels, and soil and vegetation indexes are analyzed with the aid of methods such as numerical statistics, linear regression, and correlation analysis with the aid of the Origin software. The results show that there is a significant negative correlation between groundwater table (GWT) and soil water content (SWC), soil conductivity, soil organic matter (SOM), soil available nitrogen (SAN), and soil available potassium (SAK). Mining activities have led to the destruction of the soil structure, greatly reducing its ability to retain water and fertilizer. The contents of SWC, SOM, and SAN in the mining area are significantly reduced, which are at least 49.73%, 47.56% and 59.90% lower than those around the mining area. On the northern and southern sides of the lake, serious soil salinization exists in the lakeshore zone where the depth to the water table is <0.5 m, and the water required for the growth of vegetation here mainly comes from the groundwater, so there are only a few water-loving and saline-resistant plants; when the depth to the water table is 0.5–7 m, the growth of surface vegetation is influenced by the double impacts of the water table and atmospheric precipitation with a high degree of species richness; when the depth to the water table is >7 m, the surface vegetation is only dependent on the limited atmospheric precipitation for water. When the depth of groundwater is >7 m, the surface vegetation only relies on limited atmospheric precipitation for water, and drought-tolerant plants mainly grow in these areas. This study not only provides a scientific basis for the sustainable development and environmental protection of similar mines in the world, but also has important significance in guiding the ecological management and rational utilization of water resources in coal mine areas. What is more, This study provides valuable insights into sustainable water resource management in arid and semi-arid regions, crucial for mitigating the ecological impacts of coal mining activities. [ABSTRACT FROM AUTHOR]

SUMMARY Soil salinization is becoming a great threat that reduces crop productivity worldwide. In this study, we found that rice allantoate amidohydrolase (OsAAH) expression was significantly upregulated by salt stress, and its overexpression conferred salt tolerance at the seedling stage. Compared to wild type (WT), the contents of ureides (allantoin and allantoate) were significantly increased in Osaah mutants and reduced in OsAAH overexpression lines both before and after salt treatments. Exogenous allantoin significantly promoted salt tolerance in OsAAH overexpression, but not in Osaah mutants. Subcellular localization showed that OsAAH was also localized to the peroxisomes in addition to the previously reported endoplasmic reticulum (ER). The differential expression of peroxisome‐related genes was identified between Osaah mutants and WT. Furthermore, the contents of H2O2 and malondialdehyde (MDA) were significantly accumulated in Osaah mutants and reduced in OsAAH overexpression lines. The activities of antioxidant enzymes were significantly reduced in Osaah mutants and enhanced in OsAAH overexpression under NaCl treatment. The transcription factor OsABI5 could directly bind to OsAAH promoter and activate OsAAH expression. Our findings reveal that OsAAH could be induced by salt stress through the activation of OsABI5 and then confer salt tolerance by enhancing the scavenging capacity of reactive oxygen species (ROS), which contributes to rice breeding in salt tolerance. [ABSTRACT FROM AUTHOR]

RNA-sequencing enables the comprehensive detection of gene expression levels at specific time points and facilitates the identification of stress-related genes through co-expression network analysis. Understanding the molecular mechanisms and identifying key genes associated with salt tolerance is crucial for developing rice varieties that can thrive in saline environments, particularly in regions affected by soil salinization. In this study, we conducted an RNA-sequencing-based time-course transcriptome analysis of 'Jao Khao', a salt-tolerant Thai rice variety, grown under normal or saline (160 mM NaCl) soil conditions. Leaf samples were collected at 0, 3, 6, 12, 24, and 48 h. In total, 36 RNA libraries were sequenced. 'Jao Khao' was found to be highly salt-tolerant, as indicated by the non-significant differences in relative water content, cell membrane stability, leaf greenness, and chlorophyll fluorescence over a 9-day period under saline conditions. Plant growth was slightly retarded during days 3–6 but recovered by day 9. Based on time-series transcriptome data, we conducted differential gene expression and weighted gene co-expression network analyses. Through centrality change from normal to salinity network, 111 key hub genes were identified among 1,950 highly variable genes. Enriched genes were involved in ATP-driven transport, light reactions and response to light, ATP synthesis and carbon fixation, disease resistance and proteinase inhibitor activity. These genes were upregulated early during salt stress and RT-qPCR showed that 'Jao Khao' exhibited an early upregulation trend of two important genes in energy metabolism: RuBisCo (LOC_Os10g21268) and ATP synthase (LOC_Os10g21264). Our findings highlight the importance of managing energy requirements in the initial phase of the plant salt-stress response. Therefore, manipulation of the energy metabolism should be the focus in plant resistance breeding and the genes identified in this work can serve as potentially effective candidates. [ABSTRACT FROM AUTHOR]

Soil salinization limits rice growth and is an important restriction on grain yield. Jacalin-related lectins are involved in multiple stress responses, but their role in salt stress responses and use as molecular markers for salt tolerance remain poorly understood. Salt stress treatments and RT-qPCR analyses of Sea Rice 86 (SR86), 9311, and Nipponbare (Nip) showed that OsJRL45 and OsJRL40 enhanced tolerance of salt stress in SR86. Molecular markers based on sequence differences in SR86 and the salt-sensitive variety, 9311, in the intergenic region between OsJRL45 and OsJRL40 were validated in recombinant inbred lines derived from SR86 and 9311, hybrid populations, and common rice varieties. Yeast two-hybrid and bimolecular fluorescence complementation demonstrated that OsJRL45 and OsJRL40 interacted. Co-transformation of Nip with OsJRL45 and OsJRL40 derived from SR86 had no effect on the mature phenotype in T2 plants; however, salt stress at the three-leaf stage led to significant increases in CAT, POD, SOD, and Pro contents, but reduced MDA content in transgenic plants. Transcriptomic analysis identified 834 differentially expressed genes in transgenic plants under salt stress. GO and KEGG enrichment analyses indicated that metabolic pathways related to antioxidant responses and osmotic balance were crucial for salt-stress tolerance. Thus, molecular markers based on nucleotide differences in OsJRL45 and OsJRL40 provide a novel method for identifying salt-tolerant rice varieties. [ABSTRACT FROM AUTHOR]

Soil salinization is currently one of the main abiotic stresses that restrict plant growth. Plant endophytic bacteria can alleviate abiotic stress. The aim of the current study was to isolate, characterize, and assess the plant growth-promoting and saline and alkaline stress-alleviating traits of Peribacillus simplex M1 (P. simplex M1) isolates from maize. One endophytic bacterial isolate, named P. simplex M1, was selected from the roots of maize grown in saline–alkali soil. The P. simplex M1 genome sequence analysis of the bacteria with a length of 5.8 Mbp includes about 700 genes that promote growth and 16 antioxidant activity genes that alleviate saline and alkaline stress. P. simplex M1 can grow below 400 mM NaHCO3 on the LB culture medium; The isolate displayed multiple plant growth-stimulating features, such as nitrogen fixation, produced indole-3-acetic acid (IAA), and siderophore production. This isolate had a positive effect on the resistance to salt of maize in addition to the growth. P. simplex M1 significantly promoted seed germination by enhancing seed vigor in maize whether under normal growth or NaHCO3 stress conditions. The seeds with NaHCO3 treatment exhibited higher reactive oxygen species (ROS) levels than the maize in P. simplex M1 inoculant on maize. P. simplex M1 can colonize the roots of maize. The P. simplex M1 inoculant plant increased chlorophyll in leaves, stimulated root and leaf growth, increased the number of lateral roots and root dry weight, increased the length and width of the blades, and dry weight of the blades. The application of inoculants can significantly reduce the content of malondialdehyde (MDA) and increase the activity of plant antioxidant enzymes (Catalase (CAT), Superoxide Dismutase (SOD), and Peroxidase (POD)), which may thereby improve maize resistance to saline and alkaline stress. Conclusion: P. simplex M1 isolate belongs to plant growth-promoting bacteria by having high nitrogen concentration, indoleacetic acid (IAA), and siderophore, and reducing the content of ROS through the antioxidant system to alleviate salt alkali stress. This study presents the potential application of P. simplex M1 as a biological inoculant to promote plant growth and mitigate the saline and alkaline effects of maize and other crops. [ABSTRACT FROM AUTHOR]

Salinity is one of the most brutal environmental factors limiting the productivity of crop plants because most of the crop plants are sensitive to salinity caused by high concentrations of salts in the soil, and the area of land affected by it is increasing day by day. High soil salinity causes osmotic stress, nutritional imbalance, and ion toxicity to plants and severely affects crop productivity in farming systems. The salinization of soil is causing a decrease in farmland agriculture as the world’s population rises day by day, endangering the availability of food. There are soils affected by salt all throughout the world, particularly in dry and semi-arid areas. For sustainable crop production, salt-stressed soils need to be corrected and managed in a proper way. Compared to chemical and physical methods, bioremediation is more environmental friendly method for correcting salt affected soils. The use of halophilic bacteria has been found to be an effective approach for plant promotion under salt-stress conditions. They help in enhancing the soil health and the yield of crop in salt-affected soils. This review will focus on the revitalizing the salt affected soils by using halophilic bacteria and their mechanisms in the soil and interaction with the plants. [ABSTRACT FROM AUTHOR]

Background: Soil salinization is a serious environmental hazard, limiting plant growth and production in different agro-ecological zones worldwide. Diethyl aminoethyl hexanoate (DA-6) as an essential plant growth regulator (PGR) exhibits a beneficial role in improving crop growth and stress tolerance. However, the DA-6-regulated effect and mechanism of salt tolerance in plants are still not fully understood. The objective of current study was to disclose salt tolerance induced by DA-6 in relation to changes in water and redox balance, photosynthetic function, ionic homeostasis, and organic metabolites reprogramming in white clover (Trifolium repens). Results: A prolonged duration of salt stress caused water loss, impaired photosynthetic function, and oxidative injury to plants. However, foliar application of DA-6 significantly improved osmotic adjustment (OA), photochemical efficiency, and cell membrane stability under salt stress. In addition, high salinity induced massive accumulation of sodium (Na), but decreased accumulation of potassium (K) in leaves and roots of all plants. DA-6-treated plants demonstrated significantly higher transcript levels of genes involved in uptake and transport of Na and K such as VP1, HKT8, SOS1, NHX2, NHX6, and SKOR in leaves as well as VP1, HKT1, HKT8, H+-ATPase, TPK5, SOS1, NHX2, and SKOR in roots. Metabolomics analysis further illustrated that DA-6 primarily induced the accumulation of glucuronic acid, hexanoic acid, linolenic acid, arachidonic acid, inosose, erythrulose, galactopyranose, talopyranose, urea, 1-monopalmitin, glycerol monostearate, campesterol, stigmasterol, and alanine. Conclusions: The DA-6 significantly up-regulated transcript levels of multiple genes associated with increased Na+ compartmentalization in vacuoles and Na+ sequestration in roots to reduce Na+ transport to photosynthetic organs, thereby maintaining Na+ homeostasis under salt stress. The accumulation of many organic metabolites induced by the DA-6 could be attributed to enhanced cell wall and membrane structural stability and functionality, OA, antioxidant defense, and downstream signal transduction in leaves under salt stress. The present study provides a deep insight about the synergistic role of DA-6 in salt tolerance of white clover. [ABSTRACT FROM AUTHOR]

Soil salinization presents a considerable risk to agricultural sustainability globally. Remote sensing technology facilitates extensive monitoring and assessment of soil salinization, thus providing technical support for its prevention and management. This study utilizes bibliometric methods to examine the attributes of publications, key research areas, and their evolutionary trends within the domain of soil salinization remote sensing evaluation, spanning 1999 to 2023, using data from the Web of Science Core Collection. Visualization is facilitated by CiteSpace software. The results indicate: (1) In terms of research trends, international investigations into remote sensing monitoring of soil salinization show an overall upward trend, with France, the United States and China being the largest contributors to this field of research. The Chinese Academy of Sciences is the institution that has published the most papers, and the journal that has published the most papers is Remote Sensing; (2) In terms of collaborative networks, research institutes and government organizations contribute to a large extent to institutional collaboration. However, most cooperation is currently internal; (3) Keyword analysis demonstrates that over the past 25 years, the research field of soil salinization has evolved from preliminary quantitative monitoring to more in-depth studies using intelligent analysis. The implementation of machine learning and new-generation remote sensing satellites significantly enhances the precision and efficiency of remote sensing monitoring, pointing towards new directions for solving future soil salinization issues. This study reviews the development history of the field of soil salinization remote sensing monitoring, highlights the current state of research, clarifies the focal research areas and evolutionary trends, and offers valuable references for global monitoring of soil salinization. [ABSTRACT FROM AUTHOR]

The taproot of Glycyrrhiza uralensis is globally appreciated for its medicinal and commercial value and is one of the most popular medicinal plants. With the decline of wild G. uralensis resources, cultivated G. uralensis has become a key method to ensure supply. However, soil salinization poses challenges to G. uralensis cultivation and affects the yield and quality of it. In this study, the inhibitory effects of NaCl and Na2SO4 on yield and quality of G. uralensis were comprehensively evaluated in a three-year large-scale pot experiment, and the alleviating effects of supplementation with lanthanum nitrate (La (NO3)3) on G. uralensis were further evaluated under salt stress. The findings indicate that La (NO3)3 significantly strengthened the plant's salt tolerance by enhancing photosynthetic capacity, osmolyte accumulation, antioxidant defenses, and cellular balance of ions, which led to a substantial increase in root biomass and accumulation of major medicinal components. In comparison to the NaCl-stress treatment, the 0.75 M La (NO3)3 + NaCl treatment resulted in a 20% and 34% increase in taproot length and biomass, respectively, alongside a 52% and 43% rise in glycyrrhizic acid and glycyrrhizin content, respectively. Similar improvements were observed with 0.75 M La (NO3)3 + Na2SO4 treatment, which increased root length and biomass by 14% and 26%, respectively, and glycyrrhizic acid and glycyrrhizin content by 40% and 38%, respectively. The combined showed that application of La (NO3)3 not only significantly improved the salt resilience of G. uralensis, but also had a more pronounced alleviation of growth inhibition induced by NaCl compared to Na2SO4 stress except in the gas exchange parameters and root growth. This study provides a scientific basis for high-yield and high-quality cultivation of G. uralensis in saline soils and a new approach for other medicinal plants to improve their salt tolerance. Highlights: 1. Novel Agricultural Application of Lanthanum: Our research delves into the innovative use of the rare earth element lanthanum in agriculture, with a particular focus on its potential to enhance the salt tolerance of medicinal plants. This work offers a fresh perspective on the multifaceted applications of rare earth elements in agricultural production. 2. Enhanced Salt Tolerance in Medicinal Plants. 3. Improved Plant Performance Under Salinity. 4. Strategic Implications for Medicinal Plant Cultivation. [ABSTRACT FROM AUTHOR]

Soil salinization typically exerts a highly negative influence on soil productivity, crop yields, and ecosystem balance. As a typical region afflicted by soil salinization, the soda saline–alkali soils in the Songnen Plain of China demonstrate a clear cracking phenomena. Nevertheless, the overall spectral response to the cracked soil surface has scarcely been studied. This study intends to study the impact of salt parameters on the soil cracking process and enhance the spectral measurement method used for cracked salt-affected soil. To accomplish this goal, a controlled desiccation cracking experiment was carried out on saline soil samples. A gray-level co-occurrence matrix (GLCM) was calculated for the contrast (CON) texture feature to measure the extent of cracking in the dried soil samples. Additionally, spectroscopy measurements were conducted under different surface conditions. Principal component analysis (PCA) was subsequently performed to downscale the spectral data for band integration. Subsequently, the prediction accuracy of back-propagation artificial neural network (BP-ANN) models developed from the principal components of spectral reflectance was compared for different salt parameters. The results reveal that salt content is the dominant factor determining the cracking process in salt-affected soils, and that cracked soil samples had the highest model prediction accuracy for different salt parameters rather than uncracked blocks and 2 mm comparison soil samples. Furthermore, BP-ANN prediction models combining spectral response and CON were further developed, which can significantly enhance the prediction accuracy of different salt parameters with R2 values of 0.93, 0.91, and 0.74 and a ratio of prediction deviation (RPD) of 3.68, 3.26, and 1.72 for soil salinity, electrical conductivity (EC), and pH, respectively. These findings provide valuable insights into the cracking mechanism in salt-affected soils, thereby advancing the field of hyperspectral remote sensing for monitoring soil salinization. Furthermore, this study also aids in enhancing the design of spectral measurements for saline–alkali soils and is also helpful for local soil remediation with supporting data. [ABSTRACT FROM AUTHOR]

Soil salinization and alkalinization are pervasive environmental issues that severely restrict plant growth and crop yield. Utilizing plant growth-promoting rhizobacteria (PGPR) is an effective strategy to enhance plant tolerance to saline–alkaline stress, though the regulatory mechanisms remain unclear. This study employed biochemical and RNA-Seq methods to uncover the critical growth-promoting effects of Trichoderma spp. on Salix linearistipularis under saline–alkaline stress. The results showed that, during saline–alkaline stress, inoculation with Trichoderma sp. M4 and M5 significantly increased the proline and soluble sugar contents in Salix linearistipularis, enhanced the activities of SOD, POD, CAT, and APX, and reduced lipid peroxidation levels, with M4 exhibiting more pronounced effects than M5. RNA-Seq analysis of revealed that 11,051 genes were upregulated after Trichoderma sp. M4 inoculation under stress conditions, with 3532 genes primarily involved in carbon metabolism, amino acid biosynthesis, and oxidative phosphorylation—processes that alleviate saline–alkaline stress. Additionally, 7519 genes were uniquely upregulated by M4 under stress, mainly enriched in secondary metabolite biosynthesis, amino acid metabolism, cyanamide metabolism, and phenylpropanoid biosynthesis. M4 mitigates saline–alkaline stress-induced damage in Salix linearistipularis seedlings by reducing oxidative damage, enhancing organic acid and amino acid metabolism, and activating phenylpropanoid biosynthesis pathways to eliminate harmful ROS. This enhances the seedlings' tolerance to saline–alkaline stress, providing a basis for studying fungi–plant interactions under such conditions. [ABSTRACT FROM AUTHOR]

Soybean is an important grain, oil and feed crop, which plays an important role in ensuring national food security. However, soil salinization hinders and destroys the normal physiological metabolism of soybean, resulting in the abnormal growth or death of soybean. The XTH gene can modify the plant cell wall and participate in the response and adaptation of plants to negative stress. To elucidate the role of the overexpressed GmXTH1 gene under NaCl-induced stress in soybean, we determined the germination rate, the germination potential, the germination index, seedling SOD activity, POD activity, the MDA content and the MDA content during the germination stage of the overexpressed lines of the GmXTH1 gene, the OEAs (OEA1, OEA2 and OEA3), the interference expression line IEA2, the control mutant M18, the CAT content and the chlorophyll content. The relative expression of the GmXTH1 gene in the material OEA1 and the contents of Na+ and K+ in the roots after stress were also determined. The results showed that OEAs exhibited enhanced germination indices, including the germination rate and germination potential, and were less sensitive to stress compared with the mutant M18. In contrast, the inhibitory effect of NaCl was more pronounced in the line with a disturbed expression of GmXTH1 (IEA2). The OEAs exhibited more enzyme activities and a lower MDA content, indicating reduced oxidative stress, and maintained higher chlorophyll levels, suggesting improved photosynthetic capacity. Relative expression analysis showed that the GmXTH1 gene was rapidly up-regulated in response to NaCl, peaking at 4 h after treatment, and subsequently declining. This temporal expression pattern correlated with the enhanced salt tolerance observed in OEA1. Notably, OEA1 accumulated more Na+ and maintained higher K+ levels, indicating effective ionic homeostasis under stress. Collectively, these results suggest that the overexpression of the GmXTH1 gene may positively regulate plant responses to salt stress by modulating the antioxidant defense and ion transport mechanisms. [ABSTRACT FROM AUTHOR]

To mitigate the issues of severe farmland soil salinization, the environmental degradation stemming from the overuse of chemical fertilizers, and suboptimal soil composition, a study was conducted to investigate the influence of different types and ratios of organic fertilizers on the physical and chemical attributes of saline–alkali soil. This study aimed to investigate the relationship between different types and proportions of organic fertilizers, soil moisture, organic fertilizer application rates, organic carbon molecular structure, and the soil environment in saline–alkali soils. Reducing the application of chemical fertilizers and substituting them with organic fertilizers can improve the soil quality of saline–alkali lands. The results indicated that replacing a part of the urea with organic fertilizer in saline–alkali farmland reduced the soil salinity by 11.1 to 22.8% in the 0–60 cm soil layer, decreased the soil pH by 0.11 to 1.52%, and increased the soil redox potential (Eh) values by 2.5 to 4.3% in the 0–20 cm layer of the mild and moderate saline–alkali soils. It also decreased the accumulation of the soil organic matter (OM) during the growing season. Compared to commercial organic fertilizers, natural organic fertilizers increased the accumulation of the soil soluble carbon (DOC) and nitrogen (DON), resulting in less soil salinity accumulation. When commercial organic fertilizer was applied in a 1:1 ratio with inorganic fertilizer, the salt accumulation was minimized. Compared to conventional fertilization, organic fertilizer reduced the accumulation of the NH4+-N (ammonium nitrogen) and NO3−-N (nitrate nitrogen) in the soil by 3.1 to 22.6%. In comparison to conventional chemical fertilizers, the application of organic fertilizer in the mild and moderate saline–alkali soils increased the accumulation of the DOC, DON, microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial quotient during the grain-filling stage. Specifically, it increased the DOC, DON, and DOC/DON by 12.7 to 26.7%, 12 to 59.3%, and 15.2 to 35.5%, respectively. The application of commercial organic fertilizer in the mild saline–alkali soils increased the MBC, MBN, MBC/SOC, and MBN/TN by 37.1, 65.6, 36.7, and 4.7%, respectively. Through analyzing the relative proportions of soil surface organic carbon functional groups during the grain filling period, we observed that, after the application of organic fertilizer, the OM in the mildly salinized soils primarily originated from terrestrial plant litter, whereas, in moderately salinized soils, the OM was mainly derived from microbial sources. [ABSTRACT FROM AUTHOR]

Soil salinization, especially in arid and semi-arid regions, is one of the major abiotic stresses that affect plant growth. To mediate and boost plant tolerance against this abiotic stress, arbuscular mycorrhizal fungi (AMF) symbiosis is commonly thought to be an effective tool. So, the main purpose of this study was to estimate the role of AMF (applied as a consortium of Claroideoglomus etunicatum, Funneliformis mosseae, Rhizophagus fasciculatum, and R. intraradices species) symbiosis in mitigating deleterious salt stress effects on the growth parameters (shoot length (SL), root length (RL), shoot dry weight (SDW), root dry weight (RDW), root surface area (RSA), total root length (TRL), root volume (RV), root diameter (RD), number of nodes and leaves) of Cenchrus ciliaris L. plants through improved accumulations of photosynthetic pigments (chlorophyll a, chlorophyll b, total chlorophyll), proline and phenolic compounds. The results of this experiment revealed that the roots of C. ciliaris plants were colonized by AMF under all the applied salinity levels (0, 75, 150, 225, and 300 mM NaCl). However, the rate of colonization was negatively affected by increasing salinity as depicted by the varied colonization structures (mycelium, vesicles, arbuscules and spores) which were highest under non-saline conditions. This association of AMF induced an increase in the growth parameters of the plant which were reduced by salinity stress. The improved shoot/root indices are likely due to enhanced photosynthetic activities as the AMF-treated plants showed increased accumulation of pigments (chlorophyll a, chlorophyll b and total chlorophyll), under saline as well as non-saline conditions, compared to non-AMF (N-AMF) plants. Furthermore, the AMF-treated plants also exhibited enhanced accumulation of proline and phenolic compounds. These accumulated metabolites act as protective measures under salinity stress, hence explaining the improved photosynthetic and growth parameters of the plants. These results suggest that AMF could be a good tool for the restoration of salt-affected habitats. However, more research is needed to check the true efficacy of different AMF inoculants under field conditions. [ABSTRACT FROM AUTHOR]

We measured dark CO2 fluxes and CH4 emissions from two naturally vegetated ecosystems of the Mezquital Valley irrigated with wastewater from Mexico City. The ecosystems were characterized by high groundwater levels; the vegetation was represented mainly by saltgrass in the first plot and chairmaker's bulrush in the second. A dark chamber technique was used for the study from August 2008 to June 2009. For the two studied plots, mean values (mean ± SE) for dark ecosystem CO2 fluxes (Rtot), soil CO2 emission (Rsoil), and heterotrophic respiration (Rhet) were 26 ± 5, 14 ± 3 and 12 ± 3 mg C m–2 h–1, respectively, The annual cumulative fluxes Rtot, Rsoil and Rhet equal to 234, 127 and 103 g C m–2 y–1, respectively. The contribution of Rsoil to Rtot, and Rhet to Rsoil varied significantly over the study period, with no clear relationship to seasonal dynamics. The observed low CO2 fluxes may be due to soil salinization resulting from wastewater flooding. The fluxes of CH4 were observed in the flooded plot, with peaks up to 370 µg C m–2 h–1. The fluxes of CH4 were significantly higher when plants were present in the measurement chamber than when there were no plants, confirming the important role of plant cover in CH4 transport. Unlike CH4 fluxes, CO2 fluxes show seasonal dynamics, mainly due to their strong dependence on temperature. The observed results may be useful for properly estimating the global C budget and the contribution of saline soils to C fluxes. [ABSTRACT FROM AUTHOR]

Texture features have been consistently overlooked in digital soil mapping, especially in soil salinization mapping. This study aims to clarify how to leverage texture information for monitoring soil salinization through remote sensing techniques. We propose a novel method for estimating soil salinity content (SSC) that combines spectral and texture information from unmanned aerial vehicle (UAV) images. Reflectance, spectral index, and one-dimensional (OD) texture features were extracted from UAV images. Building on the one-dimensional texture features, we constructed two-dimensional (TD) and three-dimensional (THD) texture indices. The technique of Recursive Feature Elimination (RFE) was used for feature selection. Models for soil salinity estimation were built using three distinct methodologies: Random Forest (RF), Partial Least Squares Regression (PLSR), and Convolutional Neural Network (CNN). Spatial distribution maps of soil salinity were then generated for each model. The effectiveness of the proposed method is confirmed through the utilization of 240 surface soil samples gathered from an arid region in northwest China, specifically in Xinjiang, characterized by sparse vegetation. Among all texture indices, TDTeI1 has the highest correlation with SSC (|r| = 0.86). After adding multidimensional texture information, the R2 of the RF model increased from 0.76 to 0.90, with an improvement of 18%. Among the three models, the RF model outperforms PLSR and CNN. The RF model, which combines spectral and texture information (SOTT), achieves an R2 of 0.90, RMSE of 5.13 g kg−1, and RPD of 3.12. Texture information contributes 44.8% to the soil salinity prediction, with the contributions of TD and THD texture indices of 19.3% and 20.2%, respectively. This study confirms the great potential of introducing texture information for monitoring soil salinity in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Soil salinization, a rising issue globally, is a negative effect of the ever-changing climate, which has drawn attention to, and exacerbated problems related to soil degradation and the decline in wetland rice (Oryza sativa L.) production, leading to an unstable national economy. The use of rhizosphere inhabiting microorganisms (plant growth-promoting rhizobacteria, PGPR) is a viable method for boosting agricultural production on saline soils and reduce salt stress in rice crops. The objective of this studywas to support the development of rice under salt stress by using a consortium of bacterial strains. ‘Pokkali’ rice plants inoculated with single Bacillus tequilensis and B. aryabhattai isolates were compared with consortium and non-inoculated plants while salinity was increased and by irrigation with tap water (control), 30 mM (5 dS m-1 ) and 60 mM (10 dS m-1 ) NaCl. The present study exhibited that inoculation of a mixed inoculum at 5 dS m-1 resulted in significantly higher dry weight of the shoots and roots of seedlings (9.29 and 1.24 g, respectively)which was due to the increased SPAD value, proline content (7.55 µmol g-1 FW), and antioxidant enzyme activity in the inoculated plants. The higher accumulation of osmoprotectants such as proline supported Na+ ion reduction and antioxidant enzymes such as ascorbate peroxidase and reduced polyphenol oxidase content protect against higher cellular damage, eventually leading to increase plant growth performance in saline soil. This study demonstrates some positive effects of the locally isolated salt tolerant consortium PGPR strains on the growth of rice plants under salt stress conditions. [ABSTRACT FROM AUTHOR]

Salinization in inland soil is a major impediment to food security and sustainable development goals. For several decades farmers were abandoning their lands, which were deteriorated due to salinization, and forced to take up alternate livelihoods. However, proper scientific and technological interventions came forward in the form of inland saline water (ISW) aquaculture of several euryhaline fish and shellfish species. Among them, ISW-based Penaeus vannamei farming was found to be the most viable and profitable venture for farmers. Although this practice was appropriated with the culture parameters guided for the natural seawater system; over time it become important to determine the optimal stocking density for this novel ISW system and its impact on various physio-metabolic and molecular changes in the cultured shrimp. Given this, the present study was undertaken wherein, post-larvae 8 (PL8) of P. vannamei were experimentally reared in ISW ponds with three different stocking densities viz., n = 30 PL8/m2 (T1); n = 45 PL8/m2 (T2); and n = 60 PL8/m2 (T3), for 75 days followed by evaluation of various parameters related to stress and immune system. The study revealed significant (p < 0.05) increase in the activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in the highest stocked (T3) group. Further, the T3 group demonstrated lower haemato-biochemical indices viz., haemocyte count, haemocyanin concentration, serum protein, and triglyceride levels. However, the serum glucose and malondialdehyde (MDA) as well as stress-related genes viz., heat shock protein 70 (HSP70) and SOD genes showed significant (p < 0.05) upregulation in the T3 group as compared to the T1 group. Thus, the present study delineates the negative impact of crowding density on the overall health status of the cultured shrimp and recommends the optimum stocking density for P. vannamei in ISW ponds to be 30 PL8/m2 to obtain a healthy and disease-free crop. [ABSTRACT FROM AUTHOR]

This study focuses on detecting and mitigating soil salinization in four coastal areas of the Mekong Delta (Vietnam). Salinity patterns in the soils of the Mekong River Delta are not random but linked to land use practices and distance to the sea. We examine two quick yet reliable remote sensing-based techniques to detect the coastal aquaculture area and separate it from the inland freshwater farmland. These techniques can eventually be used to identify locations with an elevated risk of salinization in other coastal regions. Finally, we investigate a salinization mitigation solution based on creating a managed aquifer recharge system along the buffer zone that separates the coastal aquaculture area from the inland freshwater agriculture area. The implementation of an infiltration pond system is technically feasible in the Mekong Delta provided that hydrogeological characteristics, the fresh-saline interface position, and freshwater demands are considered. The transitional zone between freshwater agriculture and brackish water aquaculture in Bac Lieu, Soc Trang, Tra Vinh and Ben Tre provinces is optimal for implementing an aquifer recharge/freshwater barrier scheme. [ABSTRACT FROM AUTHOR]

Water shortage and salinization are the main challenges confronted by irrigated agriculture in semiarid and arid regions. As one of the top-three largest irrigation districts in China, the Hetao Irrigation District faces pressing challenges to reduce irrigation water use and mitigate soil and groundwater salinization. Managing water and salinity requires understanding and analyzing not only the hydrologic and agronomic processes involved but the cropping and irrigation decision-making of farmers. With this aim, we build a hydroeconomic optimization model, which integrates the agrohydrological processes of water and salt balance in the crop root zone and underlying aquifer into economic optimization of water allocation and crop production. The positive mathematical programming method is used to calibrate the model such that it can replicate base-year observations. Model results highlight that a portfolio of interventions is necessary for alleviating soil and groundwater salinization and maintaining agricultural productivity and revenues; it is thus crucial to understand their long-term, cumulative effects for the sake of sustainable irrigated agricultural production. The model can assist decision-making for water and salinity management in the HID and offer useful insights for water and salinity management in irrigated agriculture of other arid regions in the world. [ABSTRACT FROM AUTHOR]

The water and salt movement and crystallization deformation of saline soil in cold and arid regions is a complex hydrothermal–salt–mechanical coupling problem. Based on the law of mass conservation, the law of energy conservation, and the theory of permafrost mechanics, the hydrothermal–salt–mechanical coupling mathematical model of unsaturated sodium sulfate saline soil is established. The model takes into account the latent heat of phase transition, crystallization impedance, consumption of crystallization, ice crystal self-cleaning behavior, and temperature as mechanical parameters. Numerical simulations using COMSOL Multiphysics (version 5.5) software were carried out, and the outcomes were analyzed and compared with unidirectional freezing test data. The findings show that the coupled model accurately simulates heat–mass transfer, crystallization, and salt freeze–thaw deformation in unsaturated saline soil. In the unidirectional freezing process, the temperature, salt freezing deformation, and freezing depth within the saline soil showed a three-stage rule of change, and the migration of water and salt to the freezing front made the water and salt content in the freezing zone increase significantly and form a laminar distribution, and the peak of the water and salt content appeared at the freezing front. The migration of water and salt aids in forming ice and salt crystals that rapidly grow within the soil pores of the freezing zone, leading to salt freeze–thaw deformation. Furthermore, the models and results of this study offer crucial insights into the mechanisms of soil salinization, desertification, and salt freeze–thaw deformation in cold and arid regions. [ABSTRACT FROM AUTHOR]

Wheat (Triticum aestivum L.) is a mega‐staple for millions of the world's populations and its yield potential is impacted by soil salinization. This study investigated genotypic variation in salt tolerance among six wheat genotypes, Gladius, Drysdale, GD0014, GD0120, GD0180, and GD0185. The study also characterized shoot traits, photosynthetic traits, leaf Na and K concentrations, and phloem sucrose. The plants were grown under controlled growth room conditions at 0 mM NaCl (Control) and 100 mM NaCl. The results showed that the salt tolerance index (STISFW, SFW: shoot fresh weight) varied from 0.52 for GD0120 to 0.69 for GD0180. Based on the STISFW, salt tolerance for the wheat genotypes was in the order, GD0180 > Gladius > GD0185 > Drysdale > GD0014 > GD0120. Projected shoot area (PSA) at all growth stages, 14, 20, 27, 34, and 40 DAS were strongly correlated with SFW at 45 DAS. Salt treatment significantly increased phloem sucrose level in the salt intolerant, Drysdale, while having no effect on this parameter in Gladius. Gladius showed greater maintenance of stomatal conductance than Drysdale. The relative ratio of K/Na between treatment and control was strongly correlated with the relative ratio of SFW (r =.85). The correlation between PSA at 14 DAS and SFW at 45 DAS and the correlation between the relative ratio of K/Na between treatment and control with STISFW identify these parameters to be potential traits for screening salt tolerance in wheat. Higher salt tolerance in Gladius would be associated with higher maintenance of stomatal conductance and enhanced phloem sucrose transport. [ABSTRACT FROM AUTHOR]

Soil salinization poses a serious threat to sustainable ecological agricultural development. Most crops are susceptible to salt stress during the growth phase of seed germination and seedling emergence. Seed priming could activate the pre-germination metabolic processes, thereby improving seed germination and seedling growth under abiotic stress conditions. Moreover, multi-walled carbon nanotube (MWCNT), as an important class of carbon nanotubes, has been applied to promote plant growth by enhancing antioxidant defense systems and photosynthetic performance during the seedling stage. In this way, it is worth exploring the combination of pre-germination and post-germination treatments to reduce the damage of salt stress to crops. Therefore, in this study, rice seeds were firstly exposed to UV-B tube in a UV irradiation box for priming treatment (90 min). After emergence, the seedlings were transplanted into pots containing 150 mg L−1 MWCNT and 200 mM NaCl to evaluate the positive effects of nanomaterial on the growth of rice. The results demonstrated that after 28 days of salt stress exposure, the combination of UV-B priming and MWCNT significantly improved the growth performance of rice and minimized the adverse effects of salt stress, as compared with the single UV-B priming or MWCNT treatment, increasing biomass accumulation and the contents of osmoregulation substances, modulating antioxidant enzyme system, improving photosynthetic performance. This study suggested that the integration of seed priming with UV-B and soil application of MWCNT enhanced antioxidant capacity, which might increase photosynthesis and biomass accumulation, thereby improving the salt tolerance of rice. [ABSTRACT FROM AUTHOR]

Continuously rising sea levels pose severe threats to the diversity and stability of coastal ecosystems. However, the responses of endospheric and rhizospheric arbuscular mycorrhizal (AM) fungal communities to accelerated seawater intrusion and changing vegetation types unfortunately remains unknown. Such insights will assist in revealing the structure of AM fungi across different tidal zones, enabling the development of effective measures to conserve biodiversity. Here, we investigated changes in endospheric and rhizospheric AM fungal communities associated with four types of coastal vegetation in Dafeng City, Jiangsu Province, China, in response to sea level variations by analyzing their characteristics and connections to selected environmental factors. It was found that the AM fungal communities of coastal vegetation differed significantly in their compositions, diversity, and stability (the resilience or resistance of a community). Despite the responses of endospheric and rhizospheric AM fungi to soil environmental factors, the soil electrical conductivity, cation exchange content, and inorganic carbon were identified as core elements that influenced the characteristics of AM fungal communities between different coastal vegetation species. Lastly, the major endospheric and rhizospheric species of AM fungi were important predictors that explained much of the variation in the soil environment. Consequently, the dynamics of AM fungal communities were correlated with the plant–soil system under different conditions. Apart from the coastal vegetation species, the characteristics of AM fungal communities can also be driven by high salinity and the inorganic carbon content induced by the intrusion of seawater. [ABSTRACT FROM AUTHOR]

Soil salinization stands as a prominent global environmental challenge, necessitating enhanced assessment methodologies. This study is dedicated to refining soil salinity assessment in the Lake Urmia region of Iran, utilizing multi-year data spanning from 2015 to 2018. To achieve this objective, soil salinity was measured at 915 sampling points during the 2015–2018 timeframe. Simultaneously, remote sensing data were derived from surface reflectance data over the same study period. Four distinct scenarios were considered such as a newly developed spectral index (Scenario I), the newly developed index combined with other salt-based spectral indices from the literature (Scenario II), indirect spectral indices based on vegetation and soil characteristics (Scenario III), and the amalgamation of both direct and indirect spectral indices (Scenario IV). Linear Regression (LR), Support Vector Machine (SVM), and Random Forest (RF) were employed to assess soil salinity. The measured data divided to 75% of the data as the calibration dataset, while the remaining 25% constituted the validation dataset. The findings revealed a correlation between soil salinity and spectral indices from the literature, with a range of -0.53 to 0.51, while the newly developed spectral index exhibited a stronger correlation (r = 0.59). Furthermore, RF yielded superior results when using the newly developed spectral index (Scenario I). Overall, SVM emerged as the most effective model (ME = -9.678, R2 = 0.751, and RPIQ = 1.78) when integrating direct and indirect spectral indices (Scenario IV). This study demonstrates the efficacy of combining machine learning techniques with a blend of newly developed and existing spectral indices from the literature for the monitoring of soil salinity, particularly in arid and semi-arid regions. [ABSTRACT FROM AUTHOR]

Soil salinization has emerged as the major factor negatively impacting soil quality in the coastal mild saline-alkali soil of the Yangtze River estuary. Soil quality is vital to agricultural development and the restoration of saline-alkali soils has become an urgent task. Biochar is often used for saline-alkali soil improvement, but few studies have explored the combined effect of biochar and leaching on it. Herein, two biochar (rice straw biochar (RBC) and humic acid magnetically modified biochar (HMBC)) were applied to the coastal mild saline-alkali soil with different application amounts (1, 3, and 5% (w/w)) plus leaching process. The results showed that HMBC had better effects than RBC in improving soil properties (e.g., dissolved organic matter, cation exchange capacity, available phosphorus, and available potassium). The leaching process led to soil pH value dropping from 8.43 to 7.57 and electrical conductivity (EC) from 622 to 200 μs/cm. Furthermore, after the pot experiment, the concentration of soil soluble salts increased with soil depth. The salt content of the soil without leaching was significantly higher than that of the soil with leaching; after applying HMBC or RBC, the salt content of all soil layers decreased. Combined 5% HMBC and leaching also improved the seed germination rate, fresh weight, dry weight, and plant height, and the height reached 9.13 cm. Although leaching resulted in a slight decrease in chlorophyll content, the chlorophyll content increased with the increased concentration of biochar. Overall, the integrated use of a suitable biochar application amount (5% HMBC) and leaching for coastal mild saline-alkali soil could be an effective strategy to reduce soil salinity, enhance the improvement of soil quality and promote plant productivity. [ABSTRACT FROM AUTHOR]

Soil salinization during wheat cultivation considerably diminishes soil fertility and impedes wheat growth, primarily due to rhizosphere microbial community changes. Our study investigates the application of Bacillus subtilis YJ-15, a strain isolated from the rhizosphere of wheat cultivated in salinized soil, as a soil remediation agent. This strain has demonstrated significant salt tolerance, disease suppression capabilities, and growth-promoting attributes in previous studies. The wheat rhizosphere was examined to assess the impact of Bacillus subtilis YJ-15 on microbial community composition and soil fertility. Fertility of soil in saline soil was significantly increased by inoculating wheat with YJ-15. The microbial community structure within the wheat rhizosphere inoculated with Bacillus subtilis YJ-15 was analyzed through sequencing on the Illumina MiSeq platform. Phyla Proteobacteria and Acidobacteria were identified as the dominant bacteria. Basidiomycota, Mortierellomycota, and Ascomycota dominated the fungal phyla. Among the bacterial genera, Pseudomonas, Arthrobacter, and Bacillus were predominant. The predominant fungal genera included Alternaria, Cephalotrichum, Mortierella, and Chaetomium. A significant increase in Gaiella and Haliangium levels was observed in the YJ group compared to the control group. Additionally, the fungal genera Epicoccum, Sporidiobolus, and Lecythophora have significantly increased in YJ abundance. One of the potential benefits of Bacillus subtilis YJ-15 in the cultivation of wheat on salinized land is its ability to enhance the rhizosphere microbial community structure and improve soil fertility. [ABSTRACT FROM AUTHOR]

Flooding and salinization triggered by storm surges threaten the survival of coastal forests. After a storm surge event, soil salinity can increase by evapotranspiration or decrease by rainfall dilution. Here we used a 1D hydrological model to study the combined effect of evapotranspiration and rainfall on coastal vegetated areas. Our results shed light on tree root uptake and salinity infiltration feedback as a function of soil characteristics. As evaporation increases from 0 to 2.5 mm/day, soil salinity reaches 80 ppt in both sandy and clay loam soils in the first 5 cm of soil depth. Transpiration instead involves the root zone located in the first 40 cm of depth, affecting salinization in a complex way. In sandy loam soils, storm surge events homogeneously salinize the root zone, while in clay loam soils salinization is stratified, partially affecting tree roots. Soil salinity stratification combined with low permeability maintain root uptakes in clay loam soils 4/5‐time higher with respect to sandy loam ones. When cumulative rainfall is larger than potential evapotranspiration ETp (ETp/Rainfall ratios lower than 1), dilution promotes fast recovery to pre‐storm soil salinity conditions, especially in sandy loam soils. Field data collected after two storm surge events support the results obtained. Electrical conductivity (a proxy for salinity) increases when the ratio ETp/Rainfall is around 1.76, while recovery occurs when the ratio is around 0.92. In future climate change scenarios with higher temperatures and storm‐surge frequency, coastal vegetation will be compromised, because of soil salinity values much higher than tolerable thresholds. Key Points: Evapotranspiration and rainfall affect post‐storm surge soil salinity in the root zone of coastal forestsIn clay loam soils, post‐storm surge salinity stratification is beneficial for root uptakeTime to recover to pre‐storm soil salinity values depends on evapotranspiration and rainfall ratios and soil properties [ABSTRACT FROM AUTHOR]

Soil salinization is an essential risk factor for agricultural development and food security, and obtaining regional soil salinity information more reliably remains a priority problem to be solved. To improve the accuracy of soil salinity inversion, this study focuses on the Manas River Basin oasis area, the largest oasis farming area in Xinjiang, as the study area and proposes a new soil salinity inversion model based on stacked integrated learning algorithms. Firstly, we selected four machine learning regression models, namely, random forest (RF), back propagation neural network, support vector regression, and convolutional neural network, for performance evaluation. Based on the model performance, we selected the more effective RF and BPNN as the basic regression models and further constructed a stacking integrated learning model. This stacking integration learning model improved the prediction accuracy by training a secondary model to fuse the prediction results of these two basic models as new features. We compared and analyzed the stacking integrated learning model with four single machine learning regression models. Findings indicated that the stacking integrated learning regression model fitted better and had good stability; on the test set, the stacking integrated learning regression model showed a relative increase of 8.2% in R2, a relative decrease of 14.0% in RMSE, and a relative increase of 6.5% in RPD when compared to the RF model, which was the single most effective machine learning regression model, and the stacking model was able to achieve soil salinity inversion more accurately. The soil salinity in the oasis areas of the Manas River Basin tended to decrease from north to south from 2016 to 2020 from a spatial point of view, and it was reduced in April from a temporal point of view. The percentage of pixels with a high soil salinity content of 2.75–2.80 g kg−1 in the study area had decreased by 19.6% in April 2020 compared to April 2016. The innovatively constructed stacking integrated learning regression model improved the accuracy of soil salinity estimation on the basis of the superior results obtained in the training of the single optimal machine learning regression model. As a consequence, this model can provide technological backup for fast monitoring and inversion of soil salinity as well as prevention and containment of salinization. [ABSTRACT FROM AUTHOR]

Land conversion to agriculture is an important factor affecting soil ecological processes in the desert grasslands of northern China. However, soil fungalcommunity structure and function in response to Land conversion remain unclear. In this study, desert grassland, artificial shrubland, and land conversion were investigated in the western part of the Mu Us Sandland (Yanchi, Ningxia; Dingbian, Shaanxi). We found that land conversion significantly increased soil total carbon, nitrogen, and phosphorus, and available phosphorous and potassium contents. In the early stage of conversion to agricultural (April), soil fungal operational taxonomic units and abundance-based coverage estimator were lower than those of dessert grasslands and shrubland plots and had significant correlations with pH, electric conductivity, and available phosphorus and potassium. The dominant phyla strongly correlated with soil physicochemical properties. Concomitantly, the relative abundance of Glomeromycota was significantly lower, and the complexity of the network in the land conversion plots was lower than that in the shrubland plots. In the late stage of land conversion (September), soil fungal operational taxonomic units and abundance-based coverage estimator were lower in the conversion plots than in the desert grassland plots, with more complex network relationships compared to the desert grassland or shrubland plots. Symbiotrophic groups, a functional group of desert grassland soil fungi, can be used as a predictor of environmental change; in addition, land conversion decreases the relative abundance of arbuscular mycorrhizal functional groups. Our study highlights the response of soil fungal communities and functions to human disturbances in desert grasslands. Considering the potential of land conversion to agriculture to influence soil secondary salinization, there is a need for continued observation of soil ecological health over the time continuum of land conversion to agriculture. [ABSTRACT FROM AUTHOR]

Soil salinization seriously affects soilmicrobial diversity, and crop yield and quality worldwide. Microorganisms play a vital role in the process of crop yield and quality. Traditional Chinese medicine Glycyrrhiza uralensis Fisch. (licorice) can grow tenaciously in the heavily salinized land. However, the relationship between licorice plants and soilmicroorganisms is not clear. A field experiment was carried out to explore the effects of three different degrees of salinized soils on (i) licorice crop performance indicators, (ii) soil physical and chemical properties, and (iii) the changes in soil bacterial community structure and functional diversity in a semi-arid area of northwest China. The results showed that with the aggravation of soil salinization, the licorice yield, soil nutrients, and the bacterial abundance of Gemmatimonadetes and Myxococcota showed a downward trend, while the concentration of glycyrrhizic acid and liquiritin, and the bacterial abundance of Actinobacteria and Firmicutes showed an upward trend. The change of licorice yield mainly depended on the soil physical and chemical properties (e.g., EC and alkaline hydrolysable nitrogen). The change of licorice quality was more closely related to the change of bacterial diversity. The effect of bacterial diversity on liquiritin was greater than that on glycyrrhizic acid. Among them, Gemmatimonadetes were significantly negatively correlated with liquiritin and glycyrrhizic acid. These findings suggest that the increased soil Actinobacteria and Firmicutes or reduced Gemmatimonadetes and Myxococcota may provide a healthy and suitable living condition for the sustainable development of medicinal plant crops in a salinized soil ecosystem. [ABSTRACT FROM AUTHOR]

Monitoring soil salinity with remote sensing is difficult, but knowing the link between saline soil surface spectra, soil water, and salt transport processes might help in modeling for soil salinity monitoring. In this study, we used an indoor soil column experiment, an unmanned aerial vehicle multispectral sensor camera, and a soil moisture sensor to study the water and salt transport process in the soil column under different water addition conditions and investigate the relationship between the soil water and salt transport process and the spectral reflectance of the image on the soil surface. The observation results of the soil column show that the soil water and salt transportation process conforms to the basic transportation law of "salt moves together with water, and when water evaporates, salt is retained in the soil weight". The salt accumulation phenomenon increases the image spectral reflectance of the surface layer of the soil column, while soil temperature has no effect on the reflectance. As the water percolates down, water and salt accumulate at the bottom of the soil column. The salinity index decreases instantly after the addition of brine and then tends to increase slowly. The experimental results indicate that this work can capture the relationship between the water and salt transport process and remote sensing spectra, which can provide theoretical basis and reference for soil water salinity monitoring. [ABSTRACT FROM AUTHOR]

Arbuscular mycorrhizal fungi (AMF) are universally distributed in soils, including saline soils, and can form mycorrhizal symbiosis with the vast majority of higher plants. This symbiosis can reduce soil salinity and influence plant growth and development by improving nutrient uptake, increasing plant antioxidant enzyme activity, and regulating hormone levels. In this study, rhizosphere soil from eight plants in the Songnen saline-alkaline grassland was used to isolate, characterize, and screen the indigenous advantageous AMF. The promoting effect of AMF on alfalfa (Medicago sativa L.) under salt treatment was also investigated. The findings showed that 40 species of AMF in six genera were identified by highthroughput sequencing. Glomus mosseae (G.m) and Glomus etunicatum (G.e) are the dominant species in saline ecosystems of northern China. Alfalfa inoculated with Glomus mosseae and Glomus etunicatum under different salt concentrations could be infested and form a symbiotic system. The mycorrhizal colonization rate and mycorrhizal dependence of G.m inoculation were significantly higher than those of G.e inoculation. With increasing salt concentration, inoculation increased alfalfa plant height, fresh weight, chlorophyll content, proline (Pro), soluble sugar (SS), soluble protein (SP), peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activity while decreasing the malondialdehyde (MDA) content and superoxide anion production rate. The results highlight that inoculation with G.m and G.e effectively alleviated salinity stress, with G.m inoculation having a significant influence on salt resistance in alfalfa. AMF might play a key role in alfalfa growth and survival under harsh salt conditions. [ABSTRACT FROM AUTHOR]

The increasing salinity and alkalinity of soils pose a global challenge, particularly in arid regions such as Tunisia, where about 50% of lands are sensitive to soil salinization. Anthropogenic activities, including the use of treated wastewater (TWW) for irrigation, exacerbate these issues. Haloalkaliphilic bacteria, adapted to TWW conditions and exhibiting plant-growth promotion (PGP) and biocontrol traits, could offer solutions. In this study, 24 haloalkaliphilic bacterial strains were isolated from rhizosphere sample of olive tree irrigated with TWW for more than 20 years. The bacterial identification using 16S rRNA gene sequencing showed that the haloalkaliphilic isolates, capable of thriving in high salinity and alkaline pH, were primarily affiliated to Bacillota (Oceanobacillus and Staphylococcus). Notably, these strains exhibited biofertilization and enzyme production under both normal and saline conditions. Traits such as phosphate solubilization, and the production of exopolysaccharide, siderophore, ammonia, and hydrogen cyanide were observed. The strains also demonstrated enzymatic activities, including protease, amylase, and esterase. Four selected haloalkaliphilic PGPR strains displayed antifungal activity against Alternaria terricola, with three showing tolerances to heavy metals and pesticides. The strain Oceanobacillus picturea M4W.A2 was selected for genome sequencing. Phylogenomic analyses indicated that the extreme environmental conditions probably influenced the development of specific adaptations in M4W.A2 strain, differentiating it from other Oceanobacillus picturae strains. The presence of the key genes associated with plant growth promotion, osmotic and oxidative stress tolerance, antibiotic and heavy metals resistance hinted the functional capabilities might help the strain M4W.A2 to thrive in TWW-irrigated soils. By demonstrating this connection, we aim to improve our understanding of genomic fitness to stressed environments. Moreover, the identification of gene duplication and horizontal gene transfer events through mobile genetic elements allow the comprehension of these adaptation dynamics. This study reveals that haloalkaliphilc bacteria from TWW-irrigated rhizosphere exhibit plant-growth promotion and biocontrol traits, with genomic adaptations enabling their survival in high salinity and alkaline conditions, offering potential solutions for soil salinization issues. [ABSTRACT FROM AUTHOR]

Introduction: Salinity negatively affects maize productivity. However, calcium lignosulfonate (CLS) could improve soil properties and maize productivity. Methods: In this study, we evaluated the effects of CLS application on soil chemical properties, plant physiology and grain quality of maize under salinity stress. Thus, this experiment was conducted using three CLS application rates, CLS0, CLS5, and CLS10, corresponding to 0%, 5%, and 10% of soil mass, for three irrigation water salinity (WS) levels WS0.5, WS2.5, and WS5.5 corresponding to 0.5 and 2.5 and 5.5 dS/m, respectively. Results and discussion: Results show that the WS0.5 × CLS10 combination increased potassium (K 0.167 g/kg), and calcium (Ca, 0.39 g/kg) values while reducing the sodium (Na, 0.23 g/kg) content in soil. However, the treatment WS5.5 × CLS0 decreased K (0.120 g/kg), and Ca (0.15 g/kg) values while increasing Na (0.75 g/kg) content in soil. The root activity was larger in WS0.5 × CLS10 than in WS5.5 × CLS0, as the former combination enlarged K and Ca contents in the root while the latter decreased their values. The leaf glutamine synthetase (953.9 µmol/(g.h)) and nitrate reductase (40.39 µg/(g.h)) were higher in WS0.5 × CLS10 than in WS5.5 × CLS0 at 573.4 µmol/(g.h) and 20.76 µg/(g.h), leading to the improvement in cell progression cycle, as revealed by lower malonaldehyde level (6.57 µmol/g). The K and Ca contents in the leaf (881, 278 mg/plant), stem (1314, 731 mg/plant), and grains (1330, 1117 mg/plant) were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 at (146, 21 mg/plant), (201, 159 mg/plant) and (206, 157 mg/plant), respectively. Therefore, the maize was more resistance to salt stress under the CLS10 level, as a 7.34% decline in yield was noticed when salinity surpassed the threshold value (5.96 dS/m). The protein (13.6 %) and starch (89.2 %) contents were greater in WS0.5 × CLS10 than in WS5.5 × CLS0 (6.1 %) and (67.0 %), respectively. This study reveals that CLS addition can alleviate the adverse impacts of salinity on soil quality and maize productivity. Thus, CLS application could be used as an effective soil amendment when irrigating with saline water for sustainable maize production. [ABSTRACT FROM AUTHOR]

Soil salinization is one of the major factors limiting agricultural production. Utilizing beneficial microorganisms like Piriformospora indica (P. indica) to enhance plant tolerance to abiotic stresses is a highly effective method, but the influence of P. indica on the growth of soybean in natural saline-alkaline soil remains unclear. Therefore, we investigated the effects of non-inoculation, P. indica inoculation, and fertilization on the growth, antioxidant defense, osmotic adjustment, and photosynthetic gas exchange parameters of soybean under two different levels of saline-alkaline stress in non-sterilized natural salinealkaline soil. The study found that: 1) P. indica inoculation significantly promoted soybean growth, increasing plant height, root length, and biomass. Under mildly saline-alkaline stress, the increases were 11.5%, 16.0%, and 14.8%, respectively, compared to non-inoculated treatment. Under higher stress, P. indica inoculation achieved the same level of biomass increase as fertilization, while fertilization only significantly improved stem diameter. 2) Under saline-alkaline stress, P. indica inoculation significantly increased antioxidant enzyme activities and reduced malondialdehyde (MDA) content. Under mildly stress, MDA content was reduced by 47.1% and 43.3% compared to non-inoculated and fertilized treatments, respectively. Under moderate stress, the MDA content in the inoculated group was reduced by 29.9% and 36.6% compared to noninoculated and fertilized treatments, respectively. Fertilization only had a positive effect on peroxidase (POD) activity. 3) P. indica inoculation induced plants to produce more osmotic adjustment substances. Under mildly stress, proline, soluble sugars, and soluble proteins were increased by 345.7%, 104.4%, and 6.9%, respectively, compared to non-inoculated treatment. Under higher stress, the increases were 75.4%, 179.7%, and 12.6%, respectively. Fertilization had no significant positive effect on proline content. 4) With increasing stress, soybean photosynthetic capacity in the P. indica-inoculated treatment was significantly higher than in the non-inoculated treatment, with net photosynthetic rate increased by 14.8% and 37.0% under different stress levels. These results indicate that P. indica can enhance soybean's adaptive ability to saline-alkaline stress by regulating ROS scavenging capacity, osmotic adjustment substance content, and photosynthetic capacity, thereby promoting plant growth. This suggests that P. indica has great potential in improving soybean productivity in natural saline-alkaline soils. [ABSTRACT FROM AUTHOR]

Soil salinization is a major environmental threat to the entire terrestrial ecosystem. Lichens arose from the symbiosis of fungi and algae or cyanobacteria. They have a high tolerance to various extreme environments, including adaptation to saline‐alkali habitats. Thus, lichens are pioneer species on saline‐alkali soil. However, the separate resilience of the two symbiotic partners under saline‐alkali conditions remains insufficiently understood. In this study, two representative symbiotic algae, Diplosphaera chodatii and Trebouxia jamesii, were studied for their physiological response to the saline‐alkali stress by adjusting different concentrations of NaHCO3, together with their respective symbiotic fungi Endocarpon pusillum (terricolous lichen) and Umbilicaria muhlenbergii (saxicolous lichen). The results indicate that cell growth rate and biomass in all four cultures decreased in alkali‐alkaline substrate, while cellular activities and ultrastructure were affected to a distinct extent. Compared with the symbiotic fungi, the algae were found to be more active in coordinating oxidative stress and lipid peroxidation damage under the saline‐alkali stress. The antioxidant system of the alga was especially shown as a key adaptive trait and it provides an important strategy for species survival and persistence in arid saline‐alkali desert. The specific survival ability of the lichen symbiosis relies on the stress resilience advantages of the symbiotic partners in combination. Our study provided new insights into understanding the adaptation of lichen symbiosis to desert saline‐alkali soil, and the potential of lichen symbiotic algae in the future desert ecological restoration. [ABSTRACT FROM AUTHOR]

(1) Soil alkalinization and salinization represent a growing global challenge. Maize (Zea mays L.), with its relatively low tolerance to salt and alkali, is increasingly vulnerable to saline‐alkali stress. Identifying maize genotypes that can withstand salinity and alkalinity is crucial to broaden the base of salt‐alkali‐tolerant maize germplasm. (2) In this study, we screened 65 maize germplasm resources for alkali stress using a 60 mM NaHCO3 solution. We measured fifteen morphological and physiological indices, including seedling height, stem thickness, and leaf area. Various analytical methods—correlation analysis, principal component analysis, subordinate function analysis, cluster analysis, stepwise discriminant analysis, and ridge regression analysis—were used to assess the seedling alkali tolerance of these maize germplasm resources. The physiological indices of six tested maize varieties were analyzed in greater detail. (3) The findings revealed complex correlations among traits, particularly strong negative associations between conductivity and root traits such as length, volume, surface area, diameter, and number of branches. The 15 evaluation indices were reduced to 7 principal components, explaining 77.89% of the variance. By applying affiliation functions and weights, we derived a comprehensive evaluation of maize seedling alkali tolerance. Notably, three germplasms—Liang Yu 99, Bi Xiang 638, and Gan Xin 2818—demonstrated significant comprehensive seedling alkali tolerance. Cluster analysis grouped the 65 maize germplasm resources into four distinct categories (I, II, III, and IV). The results of the cluster analysis were confirmed by multiclass stepwise discriminant analysis, which achieved a correct classification rate of 92.3% for 60 maize genotypes regarding alkalinity tolerance. Using principal component and ridge regression analyses, we formulated a regression equation for alkali tolerance: D‐value = −1.369 + 0.002 * relative root volume + 0.003 * relative number of root forks + 0.006 * relative chlorophyll SPAD + 0.005 * relative stem thickness + 0.005 * relative plant height + 0.001 * relative conductivity + 0.002 * relative dry weight of underground parts. Under sodium bicarbonate stress, morphological indices and germination rates were significantly reduced, germination was inhibited, photosynthetic pigment levels in maize leaves decreased to varying degrees, and the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) significantly increased. Alkali stress markedly enhanced the antioxidant enzyme activities in maize varieties, with alkali‐resistant varieties exhibiting a greater increase in antioxidant enzyme activities than alkali‐sensitive varieties under such stress. (4) By screening for alkali tolerance in maize seedlings, the identified alkali‐tolerant genotypes can be further utilized as suitable donor parents, thereby enhancing the use of alkali‐tolerant germplasm resources and providing theoretical guidance for maize cultivation in saline‐alkaline environments. [ABSTRACT FROM AUTHOR]

The intensification of the global hydrological cycle is anticipated to increase the variability of precipitation patterns. Brackish wetlands respond to changes in precipitation patterns by regulating the absorption and release of CO2 and H2O to maintain the stability of ecosystem functions. However, there is limited understanding of how the inter‐seasonal precipitation distribution (SPD) affects ecosystem CO2 and H2O exchange compared with annual precipitation totals.Here, we conducted four consecutive years of field experiments in a brackish wetland, manipulating the proportion of precipitation across different seasons while maintaining a constant annual precipitation total. We utilized five inter‐SPD proportions (+73%, +56%, control (CK), −56%, −73%) to examine the effects of SPD on ecosystem CO2 and H2O exchange.Our findings revealed that the annual ecosystem CO2 and H2O fluxes showed a trend of decreasing with the decrease in spring precipitation distribution. Among them, the annual net ecosystem CO2 exchange, evapotranspiration, carbon use efficiency and water use efficiency were shown to be more sensitive to decrease in spring precipitation distribution and increase in summer and autumn precipitation distribution. This negative asymmetric response pattern suggests that annual ecosystem CO2 and H2O exchange is primarily governed by seasonal precipitation variability, with spring soil water–salt dynamics identified as the key driver. Therefore, this association can be explained by the fact that drought of the early growth stage exacerbates soil salinization and inhibits vegetation colonization and growth, thereby greatly impairing the annual CO2–H2O exchange capacity of brackish wetlands.Our results emphasized that the spring extreme precipitation‐induced soil water–salt conditions will greatly influence CO2 and H2O exchange in brackish wetlands in the future. These findings are crucial for improving predictions of the carbon sequestration and water‐holding capacity of brackish wetlands. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

In order to explore the effect of fishponds on soil water, salt transport and salinization in cropland wasteland, a study on soil water balance and salt distribution pattern in a cropland–wasteland–fishpond system was carried out in 2022–2023 in a typical study area selected from the Yichang Irrigation Area of the Hetao Irrigation District. A water balance model was established for the cropland–wasteland–fishpond system to analyze the effects of irrigation on soil salinity at the boundaries of the cropland, wasteland, and fishpond. The results showed that the lateral recharge from the cropland to the wasteland during spring irrigation in 2022 was 24 mm, the lateral recharge generated by fishponds to wasteland was 18 mm, and the lateral recharge from fishponds to fishpond boundaries was 34 mm. In the fertility period of 2023, the lateral recharge from cropland to wasteland was 15 mm, the lateral recharge from fishponds to wasteland was 9 mm, and the lateral recharge from fishponds to fishpond boundaries was 21 mm. Due to the low salinity content of fishpond water, it diluted the groundwater of the wasteland, and the soil salinity at the boundary between the wasteland and the fishpond was monitored. The data show that the soil salinity at the boundary of the fishpond was smaller than that of the wasteland, which indicates that the migration of fishpond water to the wasteland will not lead to an increase in the soil salinity of the wasteland, but rather to a decrease in the soil salinity of the wasteland. Fishpond regulation has a significant impact on soil and groundwater, and when the topographic conditions of the Hetao irrigation area allow, the model of cropland–wasteland–fishpond can be appropriately adopted to solve land degradation and increase the economic income of farmers; the results of the study provide a contribution for the improvement of the management of land use and soil salinization in the Hetao irrigation area. [ABSTRACT FROM AUTHOR]

Soil salinization is a major limiting factor for cotton growth in Southern Xinjiang. Studying technologies and mechanisms to improve cotton salt tolerance is of significant importance for the development and utilization of saline–alkaline land. In this study, 'Xinluzhong 40' cotton was used as the material, and 150 mmol·L−1 sodium chloride (NaCl) and 1.2% natural saline–alkaline soil extract were employed to simulate single-salt (SS) and mixed-salt (MS) stresses, respectively. The effects of different exogenous substances (sodium nitrophenolate, 24-epibrassinolide, and γ-aminobutyric acid) on the growth characteristics of cotton under salt stress were investigated. The results show that: (1) Under salt stress, the height and biomass of cotton (50 d old) were reduced. Both SS and MS stresses led to increased superoxide dismutase (SOD) activity, elevated proline (PRO) content (with an increase of 50.01% and no significant difference), and increased malondialdehyde (MDA) content (with increases of 63.14% and 32.42%, respectively). At the same time, catalase (CAT) activity decreased, Na+ and Cl− contents increased, K+ content decreased, and the K+/Na+ ratio was reduced. (2) Application of sodium nitrophenolate (S), 24-epibrassinolide (E), and γ-aminobutyric acid (G) significantly improved SOD activity and PRO content while reducing MDA content (decreased by 29.33%, 25.48%, and 30.47% compared to SS treatment; and 1.68%, 5.21%, and 5.49% compared to MS treatment, respectively). They also increased CAT activity (increased by 75.97%, 103.24%, and 80.79% compared to SS treatment; and 91.06%, 82.43%, and 119.68% compared to MS treatment, respectively) and K+/Na+ ratio (increased by 57.59%, 66.35%, and 70.50% compared to SS treatment; and 38.31%, 42.97%, and 66.66% compared to MS treatment, respectively), reduced Cl− content, and promoted increases in plant height and biomass. The effects of exogenous substances on antioxidant capacity and ion balance under salt stress were significant, particularly under SS stress. (3) Principal component analysis revealed that under SS and MS stresses, principal component 1 mainly reflects cotton's antioxidant capacity, with SOD, CAT, and PRO having high weights; principal component 2 mainly reflects cotton's ion balance and nutrient absorption, with root Na+, stem Na+, leaf Na+, root K+, and root Cl− having high weights. These findings highlight the potential of exogenous substances to improve cotton salt tolerance and provide scientific evidence for cotton cultivation on saline–alkaline land, offering new insights into cultivation techniques from an applied research perspective. [ABSTRACT FROM AUTHOR]