Low Salinity Levels Research Articles

Application of Safety-First Approach to Measure Risk Behavior of Wheat Farmers in Reclaimed Lands in Iraq for the Season 2019 (Wasit province as an Applied Model)

This study aimed to investigate the application of safety-first approach to measure the risk behavior of wheat farmers in unreclaim land. A random sample of 105 farms in Wasit province for season 2019 were used. The analysis was divided into three stages. The first stage was to estimate the production function (Cob-Douglas) of wheat using the regression method of the Robust M-Weighted Estimator (R.M.W) to represent the functional relationship between quantity of produced wheat and the independent variables (seed, fertilizers, pesticides, number of mechanical and human).The second stage included an analysis of farmers' behavior towards risk based on safety-first standards. It was found that the number of farmers affording high, medium and natural risks were 46, 24 and 33, respectively, representing 43.8%, 24.76%, 31.34% of the total farmers, respectively. Third stage analyzed the factors affecting the farmers' behavior towards risk, using a multiple logistic regression model. The results indicated that farmers having normal or medium salinity soil, long experience (more than 25 years) and those owning their agricultural lands bear the risks more than their counterparts with high salinity soils, shorter experience and tenants of agricultural lands. Therefore, the study recommends conducting maintenance operations on the main and secondary drainage networks to ensure low salinity levels to obtain high productivity.

Managing salinity for sustainable agricultural production in salt-affected soils of irrigated drylands

CONTEXTDeclining water quantity and quality and poor land, water, and crop management practices are leading to increasing soil salinity, land degradation, desertification, and threatening the overall sustainability of the crop production system in irrigated drylands. Assessments of salinity dynamics and sustainability indicators under alternative agricultural practices are needed to identify the right combination of practices that improve sustainability while minimizing land and environmental degradation. OBJECTIVEThe objective of this study was to assess the potential of conservation agriculture (CA)-based practices, water-saving irrigation, water quality, and nitrogen (N) fertilizer rates for improving the sustainability of rice-wheat (RWS) and cotton-wheat (CWS) systems in salt-affected irrigated drylands. METHODSThe study included mixed-method approaches of two years of field experiments, soil profile and groundwater salinity simulation using Hydrus-1D model, and multi-criteria trade-off analysis for the holistic assessment of alternative innovations in RWS and CWS. The treatments in experiments were composed of a combination of CA-based practices, water-saving irrigation and N rates. Fourteen sustainability indicators computed from experiments and simulation were compared to evaluate the sustainability of those cropping systems and to reveal the potential of those practices for improving sustainability. RESULTS AND CONCLUSIONSCompared to the initial conditions, the soil salinity decreased in both cropping systems, while the reduction rate was much higher in RWS than CWS (by 28%). In RWS, the conventional treatment had the lowest salinity level, while in CWS, CA (permeant bed + residue retention) had the lowest. RWS raised the groundwater table by 25% compared to CWS. The long-term scenario analysis with Hydrus-1D demonstrated that, with increased irrigation water salinity and soil evaporation rates, soil profile salinity increases by 78% in RWS and 66% in CWS. RWS had a higher net profit (+81%) and soil organic carbon (SOC) (-15%), but lower water productivity (WP) (−147%), nitrogen, and energy use efficiency (EUE) (−46%) than CWS. The CA-based practices in CWS improved sustainability indicators with higher yield and net profit (+20%), WP (+26%), SOC (+456%), and EUE (36%) with decreased soil salinity than in the conventional system. SIGNIFICANCEThe study attempts to assess the effectiveness of resource conservation technologies such as choice of crop species and cropping systems, and tillage and water and fertilizer management practices for improving sustainability. This study showed the significance of agronomic, soil, and water management practices for minimizing soil salinity. Further, the findings from this study strongly demonstrated the role of CA in sustainable agricultural production particularly under CWS in salt-affected irrigated dryland.

Methylphosphonate Degradation and Salt-Tolerance Genes of Two Novel Halophilic Marivita Metagenome-Assembled Genomes from Unrestored Solar Salterns.

Aerobic bacteria that degrade methylphosphonates and produce methane as a byproduct have emerged as key players in marine carbon and phosphorus cycles. Here, we present two new draft genome sequences of the genus Marivita that were assembled from metagenomes from hypersaline former industrial salterns and compare them to five other Marivita reference genomes. Phylogenetic analyses suggest that both of these metagenome-assembled genomes (MAGs) represent new species in the genus. Average nucleotide identities to the closest taxon were <85%. The MAGs were assembled with SPAdes, binned with MetaBAT, and curated with scaffold extension and reassembly. Both genomes contained the phnCDEGHIJLMP suite of genes encoding the full C-P lyase pathway of methylphosphonate degradation and were significantly more abundant in two former industrial salterns than in nearby reference and restored wetlands, which have lower salinity levels and lower methane emissions than the salterns. These organisms contain a variety of compatible solute biosynthesis and transporter genes to cope with high salinity levels but harbor only slightly acidic proteomes (mean isoelectric point of 6.48).

Combined effects of salinity and trematode infections on the filtration capacity, growth and condition of mussels

The blue mussel (Mytilus species complex) is an important ecosystem engineer, and salinity can be a major abiotic driver of mussel functioning in coastal ecosystems. However, little is known about the interactive effects of abiotic drivers and trematode infection. This study investigated the combined effects of salinity and Himasthla elongata and Renicola roscovita metacercarial infections on the filtration capacity, growth, and condition of M. edulis from the Baltic Sea. In a laboratory experiment, groups of infected and uninfected mussels were exposed to a wide range of salinities (6-30, in steps of 3) for 1 mo. Shell growth was found to be positively correlated with salinity and optimal at 18-24 at the end of the experiment, imposed by constraints in shell calcification under lower salinities. Mussel shell growth was not affected by H. elongata infection. While salinity had only a minor effect on tissue dry weight, infected mussels had a significantly lower tissue dry weight than uninfected mussels. Most interestingly, the combination of salinity and trematode infections negatively affected the mussels’ condition indices at lower salinity levels (6 and 9), suggesting that trematode infections are more detrimental to mussels when combined with freshening. A significant positive effect of salinity on mussel filtration was found, with an initial optimum at salinity 18 shifting to 18-24 by the end of the experiment. These findings indicate that salinity and parasite infections act as synergistic stressors for mussels, and enhance the understanding of potential future ecosystem shifts under climate change-induced freshening in coastal waters.

Mariculture of Indian white shrimp Penaeus indicus (H. Milne Edwards): Optimization of stocking density in modified extensive shrimp farming (MESF) system

Shrimp culture has become a part and parcel for continuing sustainable livelihood of the farmers in the coastal villages of Bangladesh. This study aimed to optimize stocking density for a disease-free and profitable Indian white shrimp (Penaeus indicus) farming. The experiment was conducted under three treatments each with three replications. Stocking density of 10 individuals m-2 was considered as treatment one (T1), 20 individuals m-2 as treatment two (T2) and 30 individuals m-2 as treatment three (T3) for farming Indian white shrimp. Generally, all the water quality parameters of the experimental ponds except the salinity were found within the optimum condition for Indian white shrimp culture. In modified extensive shrimp farming (MESF) system, T2 showed higher survival rate than any other treatments at a low salinity level. Besides, total production values were revealed very tiny gap between T2 and T3. Though the highest value of production was found in T3 but survival rate was lower than T2. Moreover, values of shrimp’s average body weight (ABW), daily weight gain (DWG), and specific growth rate (SGR) were the highest in T2. During 90 days of culture, the growth of the Indian shrimp was negative allometric (2.86), which value was about to the value (3.00) of isomerism. This study recommends MESF culture system for growing Indian white shrimp for a greater output in brackishwater farms. This investigation also suggests some future research by considering MESF system for other important indigenous shrimp species.

دور بعض المعاملات الكيميائية في إنبات بذور بعض طرز الفليفلة الخاضعة للإجهاد الملحي

نُفذت الدراسة في مخبر مركز البحوث الزراعية في السويداء/ الهيئة العامة للبحوث الزراعية/ سورية في عام 2020. استُخدم في الدراسة سبعة طرز من الفليفلة؛ منها خمسة طرز محلية (الطرازان المحليان 10496 و10743، قرن الغزال، الفليفلة الحلبية والفليفلة الحلوة السميكة) وسلالتان (110 و129). هدف البحث إلى تحديد تأثير معاملة البذور قبل الزراعة في قدرتها على تحمل الإجهاد الملحي. إذ قسمت البذور إلى 4 مجموعات، ونُقعت المجموعة الأولى بالماء المقطر، والمجموعة الثانية بمحلول ملح الطعام النقي 50 ميلي مول، والثالثة بمحلول البولي إيتلين غلايكول 6000 (PEG) بتركيز 16.7 ميلي مول، والرابعة بمحلول السوربيتول 250 ميلي مول. عرضت البذور بعد تجفيفها إلى عدة مستويات ملحية (0، 2، 4، 6، غ لتر-1) فضلا عن استخدام شاهد غير معامل لكل طراز. قيست مؤشرات نسبة وقوة وسرعة الإنبات. نُفذت التجربة وفقاً للتصميم العشوائي التام، وحُللت البيانات باستخدام تحليل التباين ثنائي الاتجاه عند مستوى معنوية 0.01. أظهرت الطرز سلوكاً مختلفاً حسب المعاملة ومستوى الملوحة المستخدمين، إذ أشارت النتائج إلى تفوق معاملتي الـ PEG والسوربيتول في المؤشرات المدروسة لمعظم الطرز خاصة في المستويات الخفيفة من الملوحة، فيما لم تعط معاملتي الملوحة والماء لمعظم الطرز زيادة في قيم المؤشرات المدروسة. اعتماداً على هذه النتائج، يُنصح بمعاملة بذور الفليفلة قبل الزراعة بالسوربيتول أو الـ PEG عندما يكون مستوى الملح قليلا.

Phosphorus Fertilization Enhances Productivity of Forage Corn (Zea mays L.) Irrigated with Saline Water.

Salinity is a major problem affecting crop production in many regions in the world including Morocco. Agricultural practices such as fertilization could be useful to overcome this problem and improve crop productivity. The objective of our study was to evaluate the combined effect of phosphorus fertilization and irrigation water salinity on growth, yield, and stomatal conductance of forage corn (Zea mays L.) cv. “Sy sincerro”. Field experiments were carried out for two years testing four levels of irrigation water salinity (ECw = 0.7; 2, 4, and 6 dS·m−1) and three rates of phosphorus (105, 126, and 150 kg P2O5·ha−1) fertilization conducted in a split-plot design with three replications. The obtained results show that irrigation water salinity had a negative effect on all monitored parameters. For instance, the dry matter yield reduced by an average of 19.3 and 25.1% compared to the control under saline irrigation with an EC value equal to 4 and 6 dS·m−1, respectively. The finding also showed that phosphorus applications tend to increase root weight, root length, stem length, leaf stomatal conductance, grain yield and dry matter yield under salinity conditions. For example, the addition of phosphorus with a rate of 126 and 150 kg P2O5·ha−1 respectively improved dry matter yield by an average of 4 and 9% under low salinity level (ECw = 2 dS·m−1), by 4 and 15% under medium salinity (4 dS·m−1), and by 6 and 8% under a high salinity level (6 dS·m−1). Our finding suggests that supplementary P application could be one of the best practices to reduce the adverse effects of high salinity on growth and development of forage corn.

Salinity Affects Freshwater Invertebrate Traits and Litter Decomposition

We evaluated the effect of seawater intrusion in coastal ecosystems on the freshwater invertebrate community and on leaf litter decomposition under realistic scenarios in six outdoor freshwater mesocosms containing fauna and flora, to which increasing volumes of seawater were added. The resulting salinity values were 0.28 (control, freshwater only), 2.0, 3.3, 5.5, 9.3, and 15.3 mS cm−1. The effect of salinity was assessed for 65 days after seawater intrusion, by computing the deviation of values in each treatment in relation to the control. Our results show that seawater intrusion into freshwaters will affect the invertebrate communities and organic matter decomposition, with salinities of up to 3.3–5.5 mS cm−1 having opposite effects to salinities of more than 9.3 mS cm−1. There was a net negative effect of the two highest salinities on mass loss and richness of the invertebrates associated with the decomposing leaves. Regarding the invertebrate communities of the mesocosms, there was a net negative effect of the intermediate salinity levels on abundance and richness. Invertebrate life cycle traits conferring resilience and resistance tended to increase with low and decrease with high salinity values, while avoidance traits showed an opposite trend, and these responses were more pronounced on the later stage community. These wave-like responses of the invertebrate species traits to increasing salinity suggest that the life-history and physiological adaptations most suitable to cope with osmotic stress will differ between low and high salinity levels.

Salinity and Water Temperature as Predictors of Bottlenose Dolphin (Tursiops truncatus) Encounter Rates in Upper Galveston Bay, Texas

Bottlenose dolphins (Tursiops truncatus) that inhabit urban estuaries like Galveston Bay, Texas, are exposed to cumulative stressors including pollution, fisheries, shipping, freshwater inflows, and construction operations. With continuing development, it is imperative to understand the key environmental variables that make the Galveston Bay estuary suitable habitat for this protected species. The Galveston Bay Dolphin Research Program conducted monthly photo identification surveys of bottlenose dolphins in a previously understudied 186 km2 area in upper Galveston Bay (UGB). To understand occurrence patterns in this region, we calculated monthly encounter rates of dolphins (dolphins/km) for four consecutive years (2016–2019). Using multiple linear regression models, we investigated the relationship between encounter rates, and water temperature and salinity. Monthly encounter rates ranged from 0.00 to 1.23 dolphins/km with an average of 0.34 dolphins/km (SE = 0.05). Over 80% of the variance was explained by the predictor variables water temperature and salinity (R2 = 0.820). Water temperature had a positive linear effect on encounter rates at over 23.37°C (SE = 1.42). Accordingly, higher encounter rates occurred during months with warm temperatures (May–September) compared to cooler months (November–April), indicating a predictable yearly movement pattern. Moreover, salinity was a highly significant predictor variable, with encounter rates dropping linearly with decreases in salinity. Higher numbers of dolphins are found in UGB during summer, but an exodus of dolphins occurs with low salinity levels, regardless of the time of year and water temperature. These findings should be considered during infrastructure projects (i.e., flood gate system) that may alter dolphin habitat and prey availability.

Combined Transcriptome and Proteome Analysis to Elucidate Salt Tolerance Strategies of the Halophyte Panicum antidotale Retz.

Panicum antidotale, a C4 monocot, has the potential to reclaim saline and drylands and to be utilized as fodder and forage. Its adaptability to survive saline stress has been proven with eco-physiological and biochemical studies. However, little is known about its molecular mechanisms of salt tolerance. In this study, an integrated transcriptome and proteome analysis approach, based on RNA sequencing and liquid chromatography tandem mass spectrometry (LC-MS/MS), was used to identify the said mechanisms. Plants were treated with control (0 mM), low (100 mM), and high (300 mM) sodium chloride (NaCl) treatments to distinguish beneficial and toxic pathways influencing plant biomass. The results indicated differential expression of 3,179 (1,126 upregulated/2,053 downregulated) and 2,172 (898 upregulated/1,274 downregulated) genes (DEGs), and 514 (269 upregulated/245 downregulated) and 836 (494 upregulated/392 downregulated) proteins (DEPs) at 100 and 300 mM NaCl, respectively. Among these, most upregulated genes and proteins were involved in salt resistance strategies such as proline biosynthesis, the antioxidant defense system, ion homeostasis, and sugar accumulation at low salinity levels. On the other hand, the expression of several genes and proteins involved in the respiratory process were downregulated, indicating the inability of plants to meet their energy demands at high salinity levels. Moreover, the impairments in photosynthesis were also evident with the reduced expression of genes regulating the structure of photosystems and increased expression of abscisic acid (ABA) mediated pathways which limits stomatal gas exchange. Similarly, the disturbance in fatty acid metabolism and activation of essential ion transport blockers damaged the integrity of the cell membrane, which was also evident with enhanced malondialdehyde (MDA). Overall, the analysis of pathways revealed that the plant optimal performance at low salinity was related to enhanced metabolism, antioxidative defense, cell growth, and signaling pathways, whereas high salinity inhibited biomass accumulation by altered expression of numerous genes involved in carbon metabolism, signaling, transcription, and translation. The data provided the first global analysis of the mechanisms imparting salt stress tolerance of any halophyte at transcriptome and proteome levels.

Salt Stress Affects Plastid Ultrastructure and Photosynthetic Activity but Not the Essential Oil Composition in Spearmint (Mentha spicata L. var. crispa "Moroccan").

High levels of soil salinity affect plant growth, reproduction, water and ion uptake, and plant metabolism in a complex manner. In this work, the effect of salt stress on vegetative growth, photosynthetic activity, and chloroplast ultrastructure of spearmint (Mentha spicata L. var. crispa “Moroccan”) was investigated. After 2 weeks of low concentration treatments (5, 25, and 50 mM NaCl) of freshly cut shoots, we observed that the stem-derived adventitious root formation, which is a major mean for vegetative reproduction among mints, was completely inhibited at 50 mM NaCl concentration. One-week-long, high concentration (150 mM NaCl) salt stress, and isosmotic polyethylene glycol (PEG) 6000 treatments were compared in intact (rooted) plants and freshly cut, i.e., rootless shoots. Our data showed that roots have an important role in mitigating the deleterious effects of both the osmotic (PEG treatment) and specific ionic components of high salinity stress. At 50 mM NaCl or above, the ionic component of salt stress caused strong and irreversible physiological alterations. The effects include a decrease in relative water content, the maximal and actual quantum efficiency of photosystem II, relative chlorophyll content, as well as disorganization of the native chlorophyll-protein complexes as revealed by 77 K fluorescence spectroscopy. In addition, important ultrastructural damage was observed by transmission electron microscopy such as the swelling of the thylakoid lumen at 50 mM NaCl treatment. Interestingly, in almost fully dry leaf regions and leaves, granum structure was relatively well retained, however, their disorganization occurred in leaf chloroplasts of rooted spearmint treated with 150 mM NaCl. This loss of granum regularity was also confirmed in the leaves of these plants using small-angle neutron scattering measurements of intact leaves of 150 mM NaCl-stressed rooted plants. At the same time, solid-phase microextraction of spearmint leaves followed by gas chromatography and mass spectrometry (GC/MS) analyses revealed that the essential oil composition of spearmint was unaffected by the treatments applied in this work. Taken together, the used spearmint cultivar tolerates low salinity levels. However, at 50 mM NaCl concentration and above, the ionic components of the stress strongly inhibit adventitious root formation and thus their clonal propagation, and severely damage the photosynthetic apparatus.

Methanogenesis and Salt Tolerance Genes of a Novel Halophilic Methanosarcinaceae Metagenome-Assembled Genome from a Former Solar Saltern.

Anaerobic archaeal methanogens are key players in the global carbon cycle due to their role in the final stages of organic matter decomposition in anaerobic environments such as wetland sediments. Here we present the first draft metagenome-assembled genome (MAG) sequence of an unclassified Methanosarcinaceae methanogen phylogenetically placed adjacent to the Methanolobus and Methanomethylovorans genera that appears to be a distinct genus and species. The genome is derived from sediments of a hypersaline (97–148 ppt chloride) unrestored industrial saltern that has been observed to be a significant methane source. The source sediment is more saline than previous sources of Methanolobus and Methanomethylovorans. We propose a new genus name, Methanosalis, to house this genome, which we designate with the strain name SBSPR1A. The MAG was binned with CONCOCT and then improved via scaffold extension and reassembly. The genome contains pathways for methylotrophic methanogenesis from trimethylamine and dimethylamine, as well as genes for the synthesis and transport of compatible solutes. Some genes involved in acetoclastic and hydrogenotrophic methanogenesis are present, but those pathways appear incomplete in the genome. The MAG was more abundant in two former industrial salterns than in a nearby reference wetland and a restored wetland, both of which have much lower salinity levels, as well as significantly lower methane emissions than the salterns.

The effect of salinity stress on the amount of proline, chlorophyll and sodium and potassium ions in different rice cultivars in hydroponic environment

Introduction Among the cereals, rice is the most important human food source after wheat and has a major place in human nutrition in terms of production and cultivation. This plant is susceptible to salt stress and its response to salt stress varies with growth stages, concentration and duration of impact. Materials and methods This study was carried out in factorial experiment in a completely randomized design with three replications in the research greenhouse of Sari University of Agricultural Sciences and Natural Resources in 1977-98. The first factor was 71 rice genotypes and the second factor was salinity stress with 4 levels. The germinated seeds were transferred to hydroponic medium to prepare the culture medium from Yoshida nutrient solution (Yoshida et al., 1994). Chlorophyll extraction of rice leaf by Arnon method (1997), Proline amino acid extraction from leaf tissue by Bets et al. (1973) and for determination of sodium and potassium ions from leaf by Hamada and Elnai method (1994) used. The data obtained from these traits were analyzed by SAS and SPSS statistical software and compared by means of Duncan's multiple range test and clustering of genotypes by cluster analysis of tolerant cultivars based on this. Attributes were identified. Results and discussion Results of analysis of variance for different physiological traits under salinity stress showed that genotype, salinity and their interaction effects were statistically significant at the 5% probability level for all measured traits. Comparison of mean salinity levels in all measured traits was significant at 5% probability level. It showed that proline amino acid content and leaf tissue sodium content increased with increasing salinity and zero (normal) level with minimum and salinity level 9 The highest Ds was obtained and the chlorophyll pigment and potassium content of leaf tissue decreased with increasing salinity level and the highest (zero) level and the lowest salinity level was 9 dS / m. Within plant cells, proline acts as an osmotic preserving agent between the cytoplasm and the cell vacuole, and proline protects the plant against free radical damage. In the present experiment, proline content increased significantly with increasing salinity dose. This increase was higher in tolerant cultivars than in susceptible cultivars. An important effect of increasing salinity is leaf senescence and the main factor causing leaf senescence is the decrease in chlorophyll content under salinity stress. In this study, total chlorophyll a, chlorophyll a and chlorophyll b also decreased significantly under salinity stress, which was in line with the results of Bori Boncast et al. (2013) and (Wijita et al., 2018). Higher concentrations of potassium ions in the leaves of tolerant cultivars exposed to salinity can be a adaptive response to high potassium ion storage in stomach cells in salinity stress (Fallah 2015). Aerial is one of the mechanisms of plant tolerance against salinity stress. The results of this study are in line with the results of Hong et al. (2012).Conclusions The results of this study showed that salinity stress significantly decreased chlorophyll pigment and leaf potassium ion content and significantly increased proline amino acid and sodium ion content of leaf. Mean comparison between cultivars under salinity stress showed that Shastak Mohammadi, Nemat, Tarom Ghali, GASMAL, Neda, Roshan, NONABOKRA, FL478, Dilmani and Barley at 9 dS m-1 were the most tolerant cultivars to salinity and salinity stress. Saleh, Rashti Cold, IRBLZFU, IR39595, IR29, Black tip and Dorfak at 9 dSm-1 were the most susceptible cultivars to salinity stress. Acknowledgements Thanks to Sari University of Agriculture and Natural Resources and the Genetics and Plant Breeding Laboratory for providing some of the cost of this research as well as for providing plant specimens.

Ameliorative Effects of Nitrogen Application on Vegetative Growth and Productivity in Genotypes of Ragi (Eleusine coracana Gaertn.) under Saline Conditions

Background: Salinity and low soil nitrogen availability are important growth limiting factors for most crops. The proper use of N fertilizer is not only important for growth but it may also alter the salinity tolerance of plants depending on the level of salinity. Methods: The present study was undertaken to determine the interactive effects of N nutrition and saline irrigations (3, 6, 7.2, 10, 12 and 14 dSm-1) on growth and grain productivity in two varieties of finger millet viz. VL-315 and Local Hills. Different growth and productivity parameters (like plant height, dry weight of shoot, root and leaves, dry weight of panicle/plant, no. of grains, grain yield/plant etc.) adversely affected by saline irrigations, however, nitrogen nutrition minimized at different levels of salinity. Result: The positive response of nitrogen was comparatively higher at lower salinity levels (3-7.2 dSm-1) as well as at control than higher salinity (10-14 dSm-1). The effect of salinity was lower in cv. VL- 315 than Local Hills, but the interactive effects of N nutrition and salinity also enhanced the dry weight of shoot, root, leaves, dry weight of panicles and grains/plant. It is probable that N nutrition had enhanced assimilation of NO3-1-N, through the activity of NRA which further increased total nitrogen and protein content in leaves, hence, enhanced growth, biological and grain yield in both cultivars.

Improvement of the quality in hydroponically grown fresh aromatic herbs by inducing mild salinity stress is species-specific

Abstract Profitable hydroponic production requires high quality fresh water, which is often not available for agricultural use, while desalinisation of salty water is an expensive and unsustainable technology. In the present study, we assessed the effect of mild salinity stress during the soilless cultivation of fresh peppermint and spearmint in the floating system on biomass yield, produce quality and plant secondary metabolite content. Peppermint and spearmint plants were grown for 25 days on a nutrient solution (NS) supplemented with three different NaCl concentrations (0 mM, 10 mM or 20 mM NaCl). The plant height, root length, fresh and dry weight were recorded and composition was determined on fresh tissue. The composition of essential oil was determined upon hydrodistillation and that of polyphenolic compounds by targeted ultra-performance liquid chromatography coupled with mass spectrometer (UPLC-MS/MS). Plant growth was not suspended by the addition of NaCl in the NS, except for the plant height at the highest salinity level. In peppermint, the nutritional composition was not affected by the salinity, whereas it was significantly improved in spearmint as confirmed by the nitrate content decrease and the total antioxidant capacity, total soluble phenol, total carotenoid and essential oil content increases. Simultaneously, no effect of the salinity on essential oil or polyphenolic composition in both plants was induced. In conclusion, peppermint and spearmint production is feasible in the floating system even under mild salinity conditions, without negatively affecting either the crop yield or the plant's essential oil or phenolic composition. Indeed, low salinity levels improved the nutritional composition of spearmint plants.

Bioformulation of Silk-Based Coating to Preserve and Deliver Rhizobium tropici to Phaseolus vulgaris Under Saline Environments.

Seed priming has been for a long time an efficient application method of biofertilizers and biocontrol agents. Due to the quick degradation of the priming agents, this technique has been limited to specific immediate uses. With the increase of awareness of the importance of sustainable use of biofertilizers, seed coating has presented a competitive advantage regarding its ability to adhere easily to the seed, preserve the inoculant, and decompose in the soil. This study compared primed Phaseolus vulgaris seeds with Rhizobium tropici and trehalose with coated seeds using a silk solution mixed with R. tropici and trehalose. We represented the effect of priming and seed coating on seed germination and the development of seedlings by evaluating physiological and morphological parameters under different salinity levels (0, 20, 50, and 75 mM). Results showed that germination and morphological parameters have been significantly enhanced by applying R. tropici and trehalose. Seedlings of coated seeds show higher root density than the freshly primed seeds and the control. The physiological response has been evaluated through the stomatal conductance, the chlorophyll content, and the total phenolic compounds. The stability of these physiological traits indicated the role of trehalose in the protection of the photosystems of the plant under low and medium salinity levels. R. tropici and trehalose helped the plant mitigate the negative impact of salt stress on all traits. These findings represent an essential contribution to our understanding of stress responses in coated and primed seeds. This knowledge is essential to the design of coating materials optimized for stressed environments. However, further progress in this area of research must anticipate the development of coatings adapted to different stresses using micro and macro elements, bacteria, and fungi with a significant focus on biopolymers for sustainable agriculture and soil microbiome preservation.

Efficiency of enhanced oil recovery by original and low salinity waterflooding treatment

The article presents the results of research on the possibility of increasing the recovery factor of oil fields by implementing the waterflooding treatment as one of the most common enhanced oil recovery method. Based on the interpretation of data from the core flow tests, an attempt was made to characterize the displacement process using original reservoir brine and waters with lower salinity level. Additionally, the relation between the type of wettability of the rock and recovery factor was investigated. Original reservoir fluids that were characterized in terms of their basic rheological parameters were used for research purposes. The rock material consisted of 16 samples of Cambrian sandstones. The initial scope of work concerned the petrophysical characteristics of the cores, including the determination of their basic parameters, such as absolute gas permeability, porosity and pore volume. Based on the determined values of permeability, the available samples were grouped which made it possible to perform test sets for pairs with the most similar filtration parameters in the next stages of the research. Further work included the performance of relative permeability analyses and the determination of the value of the mobility factor for the oil – reservoir water system in order to determine the type of wettability of the rock and the potential efficiency of the oil displacement process. The main element of the research was the simulation of the waterflooding process carried out in two parts – the first with the use of the original reservoir water (corresponding to the secondary recovery methods) and the second with the use of low-salinity waters (the third recovery methods) in two variants of the mineralization level. Based on the obtained data of the displaced oil, for each of the displacement medium recovery factor curve were constructed and compared with the determined type of wettability of the rock.

Inconsistent response of bacterial phyla diversity and abundance to soil salinity in a Chinese delta

Soil salinization is an increasingly serious problem and decreases crop yields in the Yellow River Delta (YRD), but its effects on bacterial community and diversity at the phylum level are not well known. We used high-throughput sequencing of soil bacterial 16S rRNA to identify soil bacterial communities and diversity across a gradient of soil salinity (electrical conductivity), namely, S1: low salinity level (1.78 ds/m), S2: medium salinity level (3.16 ds/m), S3: high salinity level (17.26 ds/m), S4: extreme salinity level (34.41 ds/m), and a non-salted site as the control (CK, 0.92 ds/m). Our results indicated the significantly higher values of soil C/N ratio in S2, S3, and S4 compared with that in CK. Significantly lower values of the Shannon and Chao 1 indexes were observed in S4 compared with the CK (p < 0.05). High salinity decreased the relative abundance of Actinobacteria and Acidobacteria, but increased that of Gemmatimonadetes and Bacteroidetes. Additionally, the Shannon diversity of Bacteroidetes increased by 15.5% in S4 compared with that in the CK. Our results indicate that soil salt is a main factor regulating bacterial phyla diversity and community in the extremely saline-alkaline soils of YRD. The high abundance and diversity of Bacteroidetes can be used for saline-alkali land restoration.

The Effect of Ascophyllum nodosum Extract on the Nutraceutical Antioxidant Potential of Vigna radiata Sprout under Salt Stress.

Mung bean (Vigna radiata L.) sprout is a popular fresh vegetable, tasty and high in antioxidants. To increase yield and quality after the occurrence of both abiotic and biotic stresses, the application of seaweed extracts is of great importance. Hence, this study was conducted to determine the effect of Ascophyllum nodosum extract (ANE) in the presence of salt on the antioxidant potential of V. radiata sprouts. Different concentrations of ANE viz. 0.00, 0.01, 0.05, 0.10, and 0.50% and NaCl 0, 25, 50, 75, and 100 mM alone and in combinations were tested for researching the antioxidant potential of V. radiata sprouts at 0, 24, and 36 h of sprouting. The DPPH free-radical-scavenging activity of sprouts of V. radiata was found to increase with time and peaked at 24 h of treatment. The A. nodosum extract (0.01%) could reverse the ill effect of the low level of salinity posed by up to 25 mM NaCl. The increasing salinity deteriorated the antioxidant activity using ABTS method of sprouts down to 20.45% of the control at 100 mM NaCl. The total phenolic content (TPC), total flavonoid content (TFC), and reducing power of V. radiata sprouts was found to increase till 36 h of sprouting. A slight increase in TPC, TFC and reducing power was observed when seeds were treated with low concentrations of ANE. The elevation in TPC, TFC and reducing power upon treatment with low concentrations of ANE was also noticed in sprouts in saline combinations. Alpha amylase inhibition activity was found to reach a (67.16% ± 0.9) maximum at 24 h of sprouting at a 0.01% concentration of ANE. Tyrosinase inhibition and alpha glucosidase inhibition was 88.0% ± 2.11 and 84.92% ± 1.2 at 36 h of sprouting, respectively, at 0.01% concentration of ANE. A. nodosum extract is natural, environmentally friendly, and safe, and could be used as one of the strategies to decline stress at a low level and enhance the antioxidant activities in V. radiata sprouts, thus increasing its potential to be developed as an antioxidant-based functional food.

Salinization depresses soil enzyme activity in metal-polluted soils through increases in metal mobilization and decreases in microbial biomass.

Salinity may increase metal mobilization with a potentially significant consequence for soil enzymatic activity and nutrient cycling. The goal of this study was to investigate changes in soil enzyme activity in response to salinization of a clay loam soil artificially polluted with cadmium (Cd) and lead (Pb) during a 120-day incubation experiment. Soil samples were polluted with Cd (10 mg Cd kg-1), Pb (150 mg Pb kg-1), and a combination of Cd and Pb, then preincubated for aging and eventually salinized with three levels of NaCl solution (control, low and high). NaCl salinity consistently increased the mobilization of Cd (12-22%) and Pb (5-16%) with greater increases at high (17-22% for Cd, 9-16% for Pb) than low (12% for Cd, 5-7% for Pb) salinity levels. While the increased Cd mobilization was greater in co-polluted (22%) than Cd-polluted (17%) soils, the increase of Pb mobilization was lower in co-polluted (9%) than Pb-polluted (16%) soils at high salinity level. The salinity-induced increases in metal mobilization significantly depressed soil microbial respiration (up to 43%), microbial biomass content (up to 63%), and enzymatic activities (up to 87%). The multivariate analysis further supported that the increased soil electrical conductivity, Cd mobilization, and pH after salinization were the most important factors governing microbial activity and biomass in metal-polluted soils. Results showed that changes in microbial biomass and mobile metal pool with increasing salinity had a major effect on enzyme activities, particularly under the combined metals. This study indicated that the secondary salinization of metal-polluted soils would impose an additional stress on enzymatic activities as biochemical indicators of soil quality, and therefore should be avoided for the maintenance of soil microbial and biochemical functions, especially in arid regions. In metal-polluted soils, the observed responses of extracellular and intracellular enzymes to salinity can be used to advance our knowledge of microbial processes when modeling the carbon and nutrient cycling.