Saline Soils Research Articles

Studies on Genetic Variability and Heritability in Rice Genotypes (Oryza sativa. L.) under Salinity

Rice (Oryza sativa L.) is one of the most important staple food crops in the world because more than half of the world's population depends on rice for their livelihood. By 2050, the world's rice productivity will need to double in order to keep up with population growth. Narrow genetic base in the released variety has made the improvement in plateaus. In order to go more than the yield barrier, the genetic base must be broadened. Heritability and genetic variability were measured in eighty-six rice genotypes in terms of yield and yield contributing traits under saline soils. Significant differences were found between the genotypes for all of the studied traits according to analysis of variance. High PCV and GCV were recorded for the traits viz., mortality percentage (%), total number of grains per panicle, number of un-filled grains per panicle, sterility percentage (%) and seed yield per plant (g). The traits showed a significant degree of genetic advancement together with high heritability were mortality percentage (%), 1000 grain weight (g) and seed yield per plant (g). Genetic advance over mean were high for mortality percentage (%), number of productive tillers/m2, total number of grains per panicle (g), number of un-filled grains per panicle (g), sterility percentage (%), 1000 grain weight (g) and seed yield per plant (g). This study provides information about the variability and heritability measures which may supplement the breeding program to break the yield plateaus.

Effects of Salt Stress on Seed Germination and Embryo Growth of Oxytropis coerulea

Background: Oxytropis coerulea is considered to be an exceptional forage. The salinization of soil is a prevalent ecological issue worldwide. In order to study the effects of saline solution on seed germination and embryo growth of O. coerulea. Methods: An experiment was carried out using the culture dish filter paper method. Three salt stresses, namely, Na2CO3, NaCl and double salt were set, each of which was set to 0%, 0.3%, 0.6% and 0.9% concentration. Result: The results indicated that as the concentration of salt increased, there was a decrease in the germination rate, germination index and embryo growth. The activities of SOD, POD and CAT, as well as soluble protein content, initially increased and then decreased with increasing salt stress. The toxic effects of the three salts ranged from strong to weak as Na2CO3 greater than double salt greater than NaCl. The salt resistance indexes of 0.3% Na2CO3, NaCl and double salt were 53.87, 57.00 and 38.73, respectively and the salt resistance index of 0.6% NaCl was 50.21, indicating a high salt-tolerant degree. It showed certain resistance to 0.3% Na2CO3, 0.6% NaCl and 0.3% double salt. In short, the various soluble mechanisms of O. coerulea in different stages of salt stress and different salt stress levels have different reaction mechanisms, which reflect the salt stress of O. coerulea seeds. O. coerulea seeds can be planted in a suitable concentration of saline-alkali land, which can utilize the feed value and medicinal value of O. coerulea to improve economic benefits and utilize saline soil to improve the ecological environment.

Effects of Long-Term Reed Plantation on Saline Habitat

In recent years, the improvement and utilization of saline-alkaline soil has gradually shifted from engineering measures to biological measures. As a salt-tolerant plant, the reed has been preliminarily proven to have a role in improving saline-alkaline land. In order to explore the long-term effect of planting unharvested reeds on the improvement of saline-alkaline land, a pilot plot was set up in Fuping Pilot Test Base (34° 42'180"E; 109°11'49" N) near Lubo Beach, Fuping, Shaanxi, in 2012 to ascertain the improvement effect of long-term reed cultivation on saline–alkaline land. The objective was to study the long-term changes in soil pH, electrical conductivity, Ca2+, Mg2+, Cl-, SO42-, HCO3-, and CO32- contents, soil particle size and soil fertility. Results showed that (i) reed cultivation could effectively reduce soil salinization in the long term. From 2012 to 2022, the average pH of saline soil decreased from 9.42 to 8.86, and the electrical conductivity decreased from 1.20 μS/cm to 0.70 μS/cm. (ii) Reed cultivation considerably reduced the contents of Ca2+, Mg2+, Cl-, SO42-, HCO3-, and CO32- in the soil in the long term, and the reduction in each index was 5.9, 41.7, 63.5, 90.6, 81.7, 90.6, 77.9and 90.3%, respectively. (iii) Reed cultivation changed the soil structure. The soil texture of the 0–60 cm soil layer changed from silty sandy loam to silty loam from 2018 to 2022. (iv) Long-term reed planting without harvesting effectively improved soil fertility. In 2012, the content of soil organic matter was only 2.74 g/kg, but in 2022, the value reached 12.8 g/kg. Reed planting improved the physical and chemical properties of saline soil. Therefore, biological restoration of reed can be considered in low-lying saline–alkaline areas with high water volumes. Bangladesh J. Bot. 53(3): 665-672, 2024 (September) Special

Mangrove afforestation as an ecological control of invasive Spartina alterniflora affects rhizosphere soil physicochemical properties and bacterial community in a subtropical tidal estuarine wetland

Background The planting of mangroves is extensively used to control the invasive plant Spartina alterniflora in coastal wetlands. Different plant species release diverse sets of small organic compounds that affect rhizosphere conditions and support high levels of microbial activity. The root-associated microbial community is crucial for plant health and soil nutrient cycling, and for maintaining the stability of the wetland ecosystem. Methods High-throughput sequencing was used to assess the structure and function of the soil bacterial communities in mudflat soil and in the rhizosphere soils of S. alterniflora, mangroves, and native plants in the Oujiang estuarine wetland, China. A distance-based redundancy analysis (based on Bray–Curtis metrics) was used to identify key soil factors driving bacterial community structure. Results S. alterniflora invasion and subsequent mangrove afforestation led to the formation of distinct bacterial communities. The main soil factors driving the structure of bacterial communities were electrical conductivity (EC), available potassium (AK), available phosphorus (AP), and organic matter (OM). S. alterniflora obviously increased EC, OM, available nitrogen (AN), and NO3−-N contents, and consequently attracted copiotrophic Bacteroidates to conduct invasion in the coastal areas. Mangroves, especially Kandelia obovata, were suitable pioneer species for restoration and recruited beneficial Desulfobacterota and Bacilli to the rhizosphere. These conditions ultimately increased the contents of AP, available sulfur (AS), and AN in soil. The native plant species Carex scabrifolia and Suaeda glauca affected coastal saline soil primarily by decreasing the EC, rather than by increasing nutrient contents. The predicted functions of bacterial communities in rhizosphere soils were related to active catabolism, whereas those of the bacterial community in mudflat soil were related to synthesis and resistance to environmental factors. Conclusions Ecological restoration using K. obovata has effectively improved a degraded coastal wetland mainly through increasing phosphorus availability and promoting the succession of the microbial community.

Understanding of Plant Salt Tolerance Mechanisms and Application to Molecular Breeding.

Soil salinization is a widespread hindrance that endangers agricultural production and ecological security. High salt concentrations in saline soils are primarily caused by osmotic stress, ionic toxicity and oxidative stress, which have a negative impact on plant growth and development. In order to withstand salt stress, plants have developed a series of complicated physiological and molecular mechanisms, encompassing adaptive changes in the structure and function of various plant organs, as well as the intricate signal transduction networks enabling plants to survive in high-salinity environments. This review summarizes the recent advances in salt perception under different tissues, physiological responses and signaling regulations of plant tolerance to salt stress. We also examine the current knowledge of strategies for breeding salt-tolerant plants, including the applications of omics technologies and transgenic approaches, aiming to provide the basis for the cultivation of salt-tolerant crops through molecular breeding. Finally, future research on the application of wild germplasm resources and muti-omics technologies to discover new tolerant genes as well as investigation of crosstalk among plant hormone signaling pathways to uncover plant salt tolerance mechanisms are also discussed in this review.

Planting Trees on Sandy Saline Soil Increases Soil Carbon and Nitrogen Content by Altering the Composition of the Microbial Community

Planting Trees on Sandy Saline Soil Increases Soil Carbon and Nitrogen Content by Altering the Composition of the Microbial Community

Phosphogypsum with Rice Cultivation Driven Saline-Alkali Soil Remediation Alters the Microbial Community Structure.

The improvement of saline-alkali land plays a key role in ensuring food security and promoting agricultural development. Saline soils modifies the response of the soil microbial community, but research is still limited. The effects of applying phosphogypsum with rice cultivation (PRC) on soil physicochemical properties and bacterial community in soda saline-alkali paddy fields in Songnen Plain, China were studied. The results showed that the PRC significantly improved the physicochemical properties of soil, significantly reduced the salinity, increased the utilization efficiency of carbon, nitrogen, and phosphorus, and significantly increased the activities of urease and phosphatase. The activities of urease and phosphatase were significantly correlated with the contents of total organic carbon and total carbon. A redundancy analysis showed that pH, AP, ESP, HCO3-, and Na+ were dominant factors in determining the bacterial community structure. The results showed that PRC could improve soil quality and enhance the ecosystem functionality of soda saline-alkali paddy fields by increasing nutrient content, stimulating soil enzyme activity, and regulating bacterial community improvement. After many years of PRC, the soda-alkali soil paddy field still develops continuously and healthily, which will provide a new idea for sustainable land use management and agricultural development.

Mitigation of salinity stress on morpho-physiological and yield related parameters of rice using different organic amendments

Salinity is a pernicious abiotic element that hinders crop development. Utilizing organic amendments to remediate salt is crucial for enhancing soil function and promoting crop growth. Based on this, a pot experiment was carried out at the research field of Khulna Agricultural University, Khulna, to examine the physiology, growth, and yield of transplanted aman rice in response to salinity stress using duckweed, and dhaincha biomass supplement. Excess salinity with no organic amendments reduced plant growth and development, relative water content (26%), and membrane stability (28%), index compared to T1 S1 (duckweed), and T2 S1 (dhaincha) at 50 mM salinity. Salinity delayed the emergence of first flowering and the maturity of filled grains. The lowest grain yield was recorded in T0S3 (no treatment + 100 mM salinity). Application of dhaincha and duckweed biomass ameliorates salinity individually at all salinity levels. Rice grown in saline soil with the application of T1 (duckweed biomass) and T2 (Sesbania biomass) had an 87% spikelet fertility while rice grown in soil without T1 and T2 treatment had only 21.82%. The application of T2 and T1 @ 5 t ha-1 increased grain yield by 33.29% and 4.70% compared to control. Furthermore, salinity stress @100 mM NaCl with duckweed decreased grain yield by 0.05% which was minimized to 12% by applying dhaincha green manure (T2) @ 5 t ha1. The finding showed that the ameliorative impact of green manure at 5 tha1 dose (T2) was more effective compared to the duckweed (T1) at the three salinity levels used in the study.

Bacillus subtilis Strain YJ-15, Isolated from the Rhizosphere of Wheat Grown under Saline Conditions, Increases Soil Fertility and Modifies Microbial Community Structure

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.

Residual Effect of Microbial-Inoculated Biochar with Nitrogen on Rice Growth and Salinity Reduction in Paddy Soil.

Increasing soil and water salinity threatens global agriculture, particularly affecting rice. This study investigated the residual effects of microbial biochar and nitrogen fertilizer in mitigating salt stress in paddy soil and regulating the biochemical characteristics of rice plants. Two rice varieties, Shuang Liang You 138 (SLY138), a salt-tolerant, and Jing Liang You 534 (JLY534), a salt-sensitive, were grown under 0.4 ds/m EC (S0) and 6.84 ds/m EC (S1) in a glass house under controlled conditions. Three types of biochar-rice straw biochar (BC), fungal biochar (BF), and bacterial biochar (BB)-were applied alongside two nitrogen (N) fertilizer rates (60 kg ha-1 and 120 kg ha-1) in a previous study. The required salinity levels were maintained in respective pots through the application of saline irrigation water. Results showed that residual effects of microbial biochars (BF and BB) had higher salt mitigation efficiency than sole BC. The combination of BB and N fertilizer (BB + N120) significantly decreased soil pH by 23.45% and Na+ levels by 46.85%, creating a more conducive environment for rice growth by enhancing beneficial microbial abundance and decreasing pathogenic fungi in saline soil. Microbial biochars (BF and BB) positively improved soil properties (physicochemical) and biochemical and physiological properties of plants, ultimately rice growth. SLY138 significantly had a less severe response to salt stress compared to JLY534. The mitigation effects of BB + N120 kg ha-1 were particularly favorable for SLY138. In summary, the combined residual effect of BF and BB with N120 kg ha-1, especially bacterial biochar (BB), played a positive role in alleviating salt stress on rice growth, suggesting its potential utility for enhancing rice yield in paddy fields.

Assessment of the Spatiotemporal Dynamics of Suitable Habitats for Typical Halophytic Vegetation in China Based on Maxent Model and Landscape Ecology Theory

The widespread and complex formation of saline soils in China significantly affects the sustainable development of regional ecosystems. Intense climate changes and regional land use further exacerbate the uncertainties faced by ecosystems in saline areas. Therefore, studying the distribution characteristics of typical halophytic vegetation under the influence of climate change and human activities, and exploring their potential distribution areas, is crucial for maintaining ecological security in saline regions. This study focuses on Tamarix chinensis, Tamarix austromongolica, and Tamarix leptostachya, integrating geographic information systems, remote sensing, species distribution models, and landscape ecological risk (LER) theories and technologies. An optimized MaxEnt model was established using the ENMeval package, incorporating 143, 173, and 213 distribution records and 13 selected environmental variables to simulate the potential suitable habitats of these three Tamarix species. A quantitative assessment of the spatial characteristics and the area of their potential geographical distribution was conducted. Additionally, a landscape ecological risk assessment (LERA) of the highly suitable habitats of these three Tamarix species was performed using land use data from 1980 to 2020, and the results of the LERA were quantified using the Landscape Risk Index (LERI). The results showed that the suitable areas of Tamarix chinensis, Tamarix austromongolica, and Tamarix leptostachya were 9.09 × 105 km2, 6.03 × 105 km2, and 5.20 × 105 km2, respectively, and that the highly suitable habitats for the three species were concentrated in flat areas such as plains and basins. Tamarix austromongolica faced increasing ecological risk in 27.22% of its highly suitable habitat, concentrated in the northern region, followed by Tamarix chinensis in 16.70% of its area with increasing ecological risk, concentrated in the western and northern highly suitable habitats; Tamarix chinensis was the least affected, with an increase in ecological risk in only 1.38% of its area. This study provides valuable insights for the protection of halophytic vegetation, represented by Tamarix, in the context of China’s national land development.

Experimental Study on Water and Salt Migration and the Aggregate Insulating Effect in Coarse-Grained Saline Soil Subgrade under Freeze–Thaw Cycles

Understanding multiphase transformations and the migration of heat, water, vapor, and salt in coarse-grained saline soil under groundwater recharge and environmental freeze—thaw cycles is crucial for ensuring the stability of highway infrastructures. To clarify the water, heat, vapor, and salt migration patterns in coarse-grained saline soil, as well as the salt-insulating effect of the aggregate insulating layer, an experimental study was conducted in a soil column model under pressureless water replenishment with fluorescein-labeled liquid water under freeze—thaw cycles. The results showed that the temperature in the saline soil columns periodically changed and that hysteresis effects occurred during temperature transfer. External water replenishment and the content of liquid water inside the soil exhibited nonlinear changes with environmental temperatures. After multiple freeze—thaw cycles, two water and salt accumulation zones formed within the coarse-grained saline soil subgrade. The migration of liquid water resulted in a water and salt accumulation zone in the nonfrozen zone, whereas the migration of water vapor yielded a water and salt accumulation zone in the frozen zone. To prevent water and salt migration, a 20 cm thick gravel insulating layer could be laid at a distance of 10 cm from the bottom of the roadbed, which could provide a satisfactory salt-insulating effect. The research results provide a theoretical basis and guidance for regulating the stability of subgrades in saline soil areas.

La (NO3)3 substantially fortified Glycyrrhiza uralensis’s resilience against salt stress by interconnected pathways

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.Graphical

Nano Management Techniques for Soil Reclamation

The application of nano-scale management strategies for soil remediation presents a promising avenue for tackling soil salinity issues and bolstering agricultural sustainability. Nano-sized materials like gypsum, biochar, sulphur, and zinc offer novel solutions by capitalizing on their distinct properties to alleviate soil stressors and bolster soil vitality. These nano materials demonstrate heightened reactivity, mobility, and efficacy compared to traditional alternatives, facilitating precise delivery and enduring effects on soil characteristics and crop performance. Through targeted ion displacement, soil structure enhancement, and improved nutrient accessibility, nano management approaches play a pivotal role in rehabilitating saline and sodic soils, thereby fostering agricultural resilience in adverse environmental conditions. Moreover, the integration of nano technologies in farming practices holds considerable promise for advancing precision agriculture, optimizing resource utilization, and mitigating ecological concerns associated with conventional farming methods. As research in this domain advances, ongoing exploration and refinement of nano management techniques are imperative to ensure their effectiveness, safety, and long-term sustainability, thereby contributing to the establishment of robust and productive agricultural systems.

Small ubiquitin-like modifier protease gene TaDSU enhances salt tolerance of wheat.

To identify efficient salt-tolerant genes is beneficial for coping with the penalty of salt stress on crop yield. Reversible conjugation (sumoylation and desumoylation) of Small Ubiquitin-Like Modifier (SUMO) is a crucial kind of protein modifications, but its roles in the response to salt and other abiotic stress are not well addressed. Here, we identify salt-tolerant SUMO protease gene TaDSU for desumoylation from wheat, and analyze its mechanism in salt tolerance and evaluate its role in yield in saline-alkaline fields. TaDSU overexpression enhances salt tolerance of wheat. TaDSU overexpressors have lower Na+ but higher K+ contents and consequently higher K+ : Na+ ratios than the wild-type under salt stress. TaDSU interacts with transcriptional factor MYC2, reduces the sumoylation level of SUMO1-conjugated MYC2, and promotes its transcription activity. MYC2 binds to the promoter of TaDSU and elevates its expression. TaDSU overexpression enhances grain yield of wheat in the saline soil without growth penalty in the normal field. Especially, TaDSU ectopic expression also enhances salt tolerance of Arabidopsis thaliana, showing this SUMO protease allele has the inter-species role in the adaptation to salt stress. Thus, TaDSU is an efficient candidate gene for molecular breeding of salt-tolerant crops.

Influence of composted manures and co-composted biochar on growth performance of saffron and soil nutrients under varying electrical conductivity soil conditions: A two-year field study

The stigmas of saffron (Crocus sativus L.) are known as “red gold” for being the most expensive spice of the world. This medicinal crop grows well in the regions with cold winter Mediterranean climate. However, salinity can be one of the limiting factors for its cultivation in these regions. Composted manures and their co-compost with wood-derived biochar as fertilizers in saline soil can reduce the salinity stress on saffron. In this study, the composted manures from dairy farms (FYM), sheep and goats (SG) and poultry (PM) and their co-compost with wood-derived biochar (FYM-B, SG-B and PM-B) were amended in non-saline (EC1:2 0.25 dS m−1, SOM; 9.9 g kg−1) and soil with natural slight salinity (EC1:2; 1.95 dS m−1, SOM; 30.9 g kg−1) soil for two consecutive years with the total amendment rate of 65 t ha−1 for each fertilizer. The saline soil was transported from an agricultural farm (30 km away from research field); whereas, the non-saline soil was not transported and was not cultivated before. The amendment of fertilizers and sowing of corms were conducted at the same time in the mid of August. The stigma yield in saline control soil was significantly lower than non-saline control in both cropping years. In non-saline soil, all fertilizers reduced stigma yield of first-year crop by 14–60 % (P < 0.05). No differences between treatments for the stigma yield of second year crop in non-saline and of first year crop in saline soil were observed. In saline soil, FYM and PM fertilizers increased stigma yield of second year crop by 44 % and 41 %, respectively (P < 0.05). The two-year cumulative agronomic efficiencies for nitrogen and phosphorus and the nitrogen use efficiency for leaf biomass were lower under fertilizer treatments than control in non-saline and saline soil. In non-saline soil the PM-B; whereas, in saline soil all fertilizers (except SG) increased the phosphorus use efficiency of leaves (P < 0.05). The two-year amendment of composted manures and FYM-B in non-saline soil resulted in high uptake of sodium in leaves (P < 0.05); whereas, such effect was not observed for saline soil. Almost all fertilizers increased ∼2–5 fold the concentration of bioavailable phosphorus and ∼2–3 fold the concentration of potassium in non-saline and saline soil (P < 0.05). The positive influence of fertilizers on stigma yield and PUE of leaves of second year crop was observed only for saline soil. Furthermore, contrary to the results for non-saline soil, these fertilizers did not cause an increased uptake of Na in leaves in saline soil. We attribute this effect to the high concentration of SOM and gradual decline in EC (0.94–1.71 dS m−1) over time in saline soil. The gradual improvement in yield (from negative to neutral in non-saline and from neutral to positive in saline soil) was observed over time. Amendment of fertilizers and sowing of corms at same time may be the reason for their negative influence on stigma yield in low SOM-containing non-saline soil.

Effects of irrigation and nutrients managements with plant intensification on rice under saline soil

The area of salt affected agricultural soils has grown on a global scale. The toxicity of salt and the unfavorable characteristics of the soil are two major causes of the low crop productivity on salt-affected soil. Thus, effective and economical management techniques are required for crop production which may sustainable. The experiments were conducted to identify appropriate irrigation and other management practices for higher yield of Boro rice at two locations (Horinkhola, Satkhira and Batiaghata, Khulna) of saline area during two successive years (2021 and 2022). Six treatments were used, consisting of continuous ponding of irrigation water along with recommended fertilizer (farmers practice, as control), and a range of combination of irrigation water and gypsum fertilizer and foliar spray of Urea, TSP, MOP and Zinc Sulphate. The results revealed that at both locations, the treatments showed significant difference and the highest yield (7.35 t/ha at Horinkhola and 6.75 t/ha Batiaghata) were obtained in treatment T5 [Continuous saturation (0-3cm) + 50% recommended fertilizer except MoP + K2SO4 equivalent to 50% K+ OM + no ridge, high density (15 cm x 10 cm) + Change of standing water 20 days interval + Foliar application of Urea-40 g, TSP-44 g, MOP-26 g and Zinc Sulphate 3g (4 times : 25, 35, 45, 60 DAT)]. Overall, this treatment produced 19% higher yield compared to farmer’s practice, along with maximum BCR (1.57) and net profit (52,004 Tk/ha). This technique can be adopted for higher yield in saline area. Bangladesh J. Nuclear Agric, 38(1): 53-64, 2024

Premelting Theory‐Based Mechanism for Water Freezing in Saline Soil

AbstractThe unfrozen water content constitutes a pivotal parameter in freezing soil, significantly impacting its thermal‐mechanical and deformation behavior. This study delves into the alterations in soil attributes as unfrozen water content varies. It examines the influences of impurities, van der Waals forces, and Coulomb forces on the water film, employing the premelting theory as a foundation. A critical state curve quantifying the ratio of the surface charge density to impurity concentration is parameterized for various soil types. Subsequently, combining the theory of effective solution concentration, we have provided calculation methods for the particle surface parameters of pore solutions as ideal and non‐ideal dilute solutions, respectively. This has determined the key variables in the model. Additionally, through the integration of equivalent particle sizes, packing structure, and water film thickness, a calculation model is devised and verified for determining the unfrozen water content and residual water content within in freezing soil. The findings indicate that fluctuation in the unfrozen water content primarily stem from impurities. In soils with equivalent saline content, impurity levels exhibit proportionality to the equivalent particle sizes. The residual unfrozen water is predominantly present within the absorbed water layer.

ENGINEERING-GEOLOGICAL ZONING OF THE FOUNDATION PROJECT ON SALINE SOILS OF KANLIKUL DISTRICT

The article is devoted to the engineering-geological zoning of the foundation project on the saline soils of the Kanlikul district. The features of the region's geological and hydrogeological conditions, as well as the influence of soil salinity on the stability and durability of building structures, are considered. The methods of engineering-geological zoning used to assess the suitability of soils for construction are described. The article proposes solutions for designing foundations taking into account the specifics of saline soils, as well as measures to reduce the negative impact of salinization on construction sites. The work is aimed at improving design and construction practices in the region's complex geological conditions.

Integration of organic manures and inorganic fertilizers on soil properties at different growth stages and yield of paddy in coastal saline soil of Maharashtra

Integration of organic manures and inorganic fertilizers on soil properties at different growth stages and yield of paddy in coastal saline soil of Maharashtra