Total Salt Research Articles

Kajian Implementasi Informasi “Pilihan Lebih Sehat” Label Kemasan Mi Instan di Indonesia

The habitual and excessive consumption of instant noodles can have adverse effects on health, primarily due to their high salt content. Patterns of excessive salt intake in food consumption are a contributing factor to the prevalence of non-communicable diseases. The Indonesian government has issued labeling regulations regarding the inclusion of information on sugar, salt, fat content and health messages to educate the public in monitoring their daily salt intake independently. This study aims to identify the information provided on instant noodle packaging. The research comprises of inventory and identification of instant noodle packaging labels, as well as the processing of data from these labels. According to the nutrition fact, instant noodle soup has an average salt (sodium) content of 1627.65 mg/100 g and contributes to 109% of the recommended daily salt intake. Salt content in instant noodle soup is higher than in fried instant noodles. Regular instant noodle products with the code ML more frequently include warning about high sugar and salt content. The “healthier choice” instant noodles product has an average sodium level of 697.84 mg/100 g and contributes 47% of the recommended daily salt intake. The total fat, sugar and salt content of the “healthier choice” noodles are 50.63, 13.78, and 36.56% respectively lower than regular fried instant noodles. Awareness of consuming instant noodles with low fat, sugar and salt content is expected to reduce the risk of non-communicable diseases.

Insights into “wheat aroma”: Analysis of volatile components in wheat grains cultivated in saline–alkali soil

The wheat grains that are cultivated in saline–alkali soil exhibit a richer “wheat aroma” compared to their counterparts. This study characterized the composition and content of volatiles in five wheat kernel varieties, harvested from two fields with varying pH levels and total salt content in the soil. The wheat grown in soil with high pH and total salt content had significantly lower levels (p < 0.05) of ethyl 3-methylbutanoate and 1-octen-3-one and significantly higher levels (p < 0.05) of 1-butanol and 1-octen-3-ol. Among all factors, plant site contributed the highest F-value contribution rate (more than 77 %) for these four volatile compounds. Six e-nose sensors responsive to these four compounds exhibited consistent trends. Therefore, the lower of ethyl 3-methylbutanoate and 1-octen-3-one, the higher of 1-butanol and 1-octen-3-ol in wheat, grown on saline–alkali soil, served as characteristic markers for “wheat aroma”.

Investigation of the liquid water content in composite saline soil containing chloride and sulfate ions

Different salt types have different effects on the liquid water content of saline soil, resulting in differences in the physico-mechanical properties and water/salt migration process of saline soil. In order to investigate the phase transition process and the change of the liquid water content in composite saline soil, saline soils with the same total salt content and different ratios of sodium chloride and sodium sulfate were taken as the objects. The results indicated that two phase transitions occur in the saline soil with single salt type, while three phase transitions can be found in the composite saline soil with two salt types. Mirabilite crystallization contributes to the 1st phase transition, mirabilite and ice precipitate together in the 2nd phase transition process, and mirabilite, ice, and hydrohalite precipitate simultaneously in the 3rd phase transition process. The liquid water is reduced in the phase transition process during cooling, and the pore characteristic has been changed significantly. The change of the liquid water content reflects the processes of salt crystallization and ice formation in saline soil, then the amounts of ice and hydrated salt were calculated at different temperatures, and the mechanism of inhibiting the deformation of sulfate saline soil was examined by adding sodium chloride. The results have reference value for those seeking understanding of the deformation in natural composite saline soil, and these findings can provide theoretical basis for the phase transition mechanism of saline soil in cold regions.

Improvement of Saline Soil Properties and Brassica rapa L. Growth Using Biofertilizers

The decline in agricultural productivity because of soil salinization has become a global problem in recent years. Biofertilizers show great potential for soil improvement as a sustainable strategy; however, their effectiveness in improving saline soils and enhancing plant growth under saline stress is poorly understood. We assessed the effectiveness of biofertilizers in improving saline soils and enhancing crop growth under saline stress and investigated the related potential mechanisms. Changes in soil physicochemical properties, plant physiological parameters, and soil microbial communities were analyzed using pot experiments. The results showed that biofertilizer application reduced total soluble salts in the soil by 30.8% and increased Brassica rapa L. biomass by 8.4 times. Biofertilizer application increased soil organic matter, total nitrogen, and available phosphorus by 56.1%, 57.0%, and 290%, respectively. Simultaneously, superoxide dismutase, catalase, chlorophyll a, chlorophyll b, total soluble sugar, and proline levels also increased by 89.5%, 140%, 110%, 190%, and 130%, respectively. Biofertilizers increased the abundance of Bacillus and Planococcus and decreased the abundance of Mortierella and Aspergillus, which could potentially be the underlying reason for the promotion of plant growth. Overall, the results of this study demonstrate the efficacy of biofertilizers in improving saline soils and that the application of biofertilizer could greatly promote agricultural production.

A gravity-induced desalination technology effectively improving the freshwater production efficiency of freeze desalination

Low desalination efficiency and water production efficiency limit the commercial application of freeze desalination (FD) technology. In this study, three freezing temperatures were set to carry out single-stage progressive freezing desalination of brackish water in southern Xinjiang, China. The ice were melted using conventional methods and gravity-induced desalination (GD), and the salt migration law during the icing and melting process was studied. The effect of GD technology on the improvement of the output of frozen desalinated produced water was quantitatively analyzed using scenario simulation. Experimental results showed that salts accumulated towards concentrated water during FD process. The ice total dissolved solids (TDS) increased with decreasing freezing temperature, which was linearly and positively correlated with the raw water TDS. GD efficiency was significantly affected by the salt concentration of ice crystals. In the first stage (the first 450 mL), ice-melt water was salt explosive dissolution, with salt drained mass accounted for more than 85% of the total salt mass. During GD process, exponential decay of ice-melt water TDS (TDSI) was observed with increasing ice-melt water amount. Through the simulation of the two exponential equation scenarios, it was found that Scenario II (mixed water TDSI as the target value) had significantly higher water yield and production rate than Scenario I (TDSI as the target value), with an increase of more than 23%. The algebraic relationship between TDSI of mixed water and the amount of ice-melt water was derived. GD technology can effectively improve the freshwater output efficiency of the FD process, which is manifested by the fact that the ice crystals of the FD process cannot produce freshwater using conventional melting. Scenario II can produce freshwater as high as 69.83% of the total amount of the GD ice-melt water. The GD technology performed increased multiplicatively in WPdv (decrease in water production) and WPRdv (decrease in water production rate) when the TDSI of the mixed water demanded by the user was low. When FD and GD are combined to desalinate salt water, lowering the freezing temperature can significantly increase the freshwater yield, breaking the limitation of freezing temperature for FD. Therefore, an automated, energy-saving freeze desalination-gravity desalination device capable of realizing the collection of the product water according to the users' needs was conceptualized. This study provides new ideas and algorithms for accurately assessing the efficiency of water production in the combined desalination of saltwater by FD and GD.

Diversity and Biotechnological Potential of Cultivable Halophilic and Halotolerant Bacteria from the "Los Negritos" Geothermal Area.

Soil salinization is negatively affecting soils globally, and the spread of this problem is of great concern due to the loss of functions and benefits offered by the soil resource. In the present study, we explored the diversity of halophilic and halotolerant microorganisms in the arable fraction of a sodic-saline soil without agricultural practices and two soils with agricultural practices (one sodic and one saline) near the geothermal area "Los Negritos" in Villamar, Michoacán state. This was achieved through their isolation and molecular identification, as well as the characterization of their potential for the production of metabolites and enzymes of biotechnological interest under saline conditions. Using culture-dependent techniques, 62 halotolerant and moderately halophilic strains belonging to the genera Bacillus, Brachybacterium, Gracilibacillus, Halobacillus, Halomonas, Kocuria, Marinococcus, Nesterenkonia, Oceanobacillus, Planococcus, Priestia, Salibactetium, Salimicrobium, Salinicoccus, Staphylococcus, Terribacillus, and Virgibacillus were isolated. The different strains synthesized hydrolytic enzymes under 15% (w/v) of salts, as well as metabolites with plant-growth-promoting (PGP) characteristics, such as indole acetic acid (IAA), under saline conditions. Furthermore, the production of biopolymers was detected among the strains; members of Bacillus, Halomonas, Staphylococcus, and Salinicoccus showed extracellular polymeric substance (EPS) production, and the strain Halomonas sp. LNSP3E3-1.2 produced polyhydroxybutyrate (PHB) under 10% (w/v) of total salts.

MAPPING THE SALINITY STATUS OF AGRICULTURAL SOILS BETWEEN KIRIKHAN-KUMLU IN THE EASTERN MEDITERRANEAN REGION OF TURKEY WITH GEOGRAPHIC INFORMATION SYSTEMS (GIS)

In this study, it was aimed to determine the salinity status of agricultural soils between Kırıkhan-Kumlu in the Eastern Mediterranean region of Turkey by mapping with Geographic Information Systems (GIS). For this purpose, a total of 60 soil samples were taken from 0–20 and 20–40 cm depths and from 30 different points to represent the agricultural soils of Kırıkhan-Kumlu region in the Eastern Mediterranean region of Turkey. In the soil samples, pH, cation exchange capacity (CEC) and exchangeable cation (ECC) values were determined to determine some soil properties. Total salt, salinity class, sodium adsorption rate (SAR), exchangeable sodium percentage (ESP) and soluble cations (Na, Ca and Mg) were determined to determine the salinity status of the soils. According to the results of the research; as a result of the analysis carried out to determine the salinity status of the soils; pH values were determined between 6.91–7.98; total salt content between 0.02–0.13%; SAR values between 0.023–0.044 me/100 gr; ESP values between 0.35–2.96%; soluble Na content between 0.019–0.034 me/100 gr; soluble Ca content between 0.018–0.245 me/100 gr and soluble Mg content between 0.037–0.113 me/100 gr. In addition, by applying the ESP-SAR regression relationship of the soils, it was revealed that the soils tended to alkalize towards the lower layers. The salinity values obtained as a result of the study were transferred to the Geographic Information Systems (GIS) environment and interpolated by Kriging method and a salinity map of the study area was created. In conclusion, as a result of the research conducted in the soils of the study area in the Eastern Mediterranean region, it was determined that all of the agricultural soils of Kırıkhan-Kumlu region were classified as non-saline and that the soils did not have any problems in terms of salinity.

Syntaxonomy and ecological differentiation of vegetation of the class Festuco-Brometea in Mykhailivska Tsilyna Nature Reserve

The article is devoted to syntaxonomy and synphytoindication of steppe vegetation in Mykhailivska Tsilyna Nature Reserve (Sumy Region). Based on phytosociological materials collected in 2021–2022 and literature data, changes of steppe vegetation in the reserve over the past ten years have been analyzed. The plant communities of the class Festuco-Brometea were identified as two subassociations and two variants in three associations, belonging to one alliance and one order. The article provides characteristics of the syntaxa, their ecological requirements, synphytoindication indexes, and results of DCA-ordination of the obtained indexes of ecological factors. It has been found that the main ecological gradients affecting ecological and territorial differentiation of the syntaxa are the soil humidity, nitrogen content in soil, soil aeration, and total salt regime. During the study, an increasing mesophytization of the steppe vegetation was observed, caused by the absence of mowing on the territories that formerly were under the constant mowing regime.

Examining the socio-ecohydrological status of St. Martin's Island in Bangladesh

One of the most popular tourist destinations is St. Martin's Island, which features a unique state of the socio-ecological environment of Bangladesh. However, tourists, other outsiders, and the island's growing human population significantly influence the overall standard of the socio-ecological environment, which is narrowly described in existing literature. The research aims to assess the state of the socio-ecological environment, particularly the quality of water, soil,flora and fauna, housing, economic activities, cropping pattern, and key degradation of the island. A questionnaire survey was used to assess housing patterns and ownership, drinking water sources, pollutants, vegetation, cropping patterns, and environmental issues. Furthermore, water samples from coastal regions and tube wells were obtained from 138 sampling points examined in the renowned laboratory of leading Bangladesh Council of Scientific and Industrial Research (BCSIR). Measurements were made of five physiochemical parameters such as pH, Total Dissolved Solids (TDS), Electrical Conductivity (EC), arsenic, and chlorine. The profile-based soil and sand samples were assessed based on Organic matter, Total Soluble Salt, pH, and CaCO3. The study found the saltwater along the coast of the island had a range of electrical conductivity from 371 to 7830, TDS from 194 to 8692 ppm, Cl concentration from 0.50 to 2.49 mg/l, arsenic content from 0.00 to 0.49, and pH from 5.50 to 8.09. The findings indicate that semi-brick accounted for 40% of the settlement while brick made up 19.7%, and 37.9% of the settlement was used for residential purposes, and 34.8% of it was made up for commercial purposes (e.g., hotels, resorts, restaurants etc.). Most hotels and residential areas used tube well water, and the study found that pollution from nearby and distant communities was the major cause of the environmental deterioration on island.

Spatial distribution characteristics of soil water-salt gradients in the ecological buffer zone of arid zone lakes and their influencing factors

Soil salinization exerts a severe impact on environmental degradation that threatens the structure and ecological functions of lake wetland. To study the characteristics of soil water-salt in the typical plant communities in the ecological buffer zone of the arid lake wetland, three zones were selected lakeshore as the starting point in Stone House, Bird Island, and Duck Bay management stations of Lake Ebinur wetland, August 2016 and 2017. These zones, including the waterward radiation zone, the water level variation zone, and the landward radiation zone, to investigate the variation patterns of soil water-salt in different zones and soil depths (0–5, 5–10, 10–20, 20–40, 40–60 cm). The results showed that: the soil pH in different plant communities in zones were all alkaline with weak varianbility. Soil moisture and total salt content were moderately variable. According to the Xinjiang saline-alkali classification standards, soils in the three zones were classified as non-salinized soil to mildly salinized soil, heavily salinized soil to saline soil, and non-salinized soil to heavily salinized soil, respectively; soil pH and moisture content in different plant communities of the zones tended to increase along with soil deepens and salt content decreased. The differences in soil pH and moisture between different soil profiles in the same zone were not so significant, but the differences in total salt content were bigger. The soil moisture and total salt content among different zones within the same soil profile remained prominent. The relationship between soil pH, moisture content, and total salt content in waterward radiation zone and water level variation zone was complex, showing an unclear pattern. In the landward radiation zone, soil pH and total salt content were negatively correlated with moisture, while soil pH was positively correlated with total salt content. The study demonstrated that the changes in soil water-salt in Lake Ebinur Wetlands were mainly influenced by structural factors (microtopography, soil characteristics, vegetation, parent material, hydrology), followed by random factors (irrigation, soil improvement, cultivation practices, and human activities).

Co-metabolism of Na+/K+ ion regulated physiological enhancement on selenium-accumulation in Saccharomyces yeasts.

Selenium is an important nutritional supplement that mainly exists naturally in soil as inorganic selenium. Saccharomyces cerevisiae cells are excellent medium for converting inorganic selenium in nature into organic selenium. Under the co-stimulation of sodium selenite (Na2SeO3) and potassium selenite (K2SeO3), the activity of selenophosphate synthetase (SPS) was improved up to about five folds more than conventional Na2SeO3 group with the total selenite salts content of 30 mg/L. Transcriptome analysis first revealed that due to the sharing pathway between sodium ion (Na+) and potassium ion (K+), the K+ largely regulates the metabolisms of amino acid and glutathione under the accumulation of selenite salt. Furthermore, K+ could improve the tolerance performance and selenium-biotransformation yields of Saccharomyces cerevisiae cells under Na2SeO3 salt stimulation. The important role of K+ in regulating the intracellular selenium accumulation especially in terms of amino acid metabolism and glutathione, suggested a new direction for the development of selenium-enrichment supplements with Saccharomyces cerevisiae cell factory. © 2024 Society of Chemical Industry.

Postoperative fluid therapy in enhanced recovery after surgery for pancreaticoduodenectomy.

Optimal intravenous fluid management during the perioperative period for patients undergoing pancreaticoduodenectomy (PD) within the framework of enhanced recovery after surgery (ERAS) is unclear. Studies have indicated that excessive total body salt and water can contribute to the development of oedema, leading to increased morbidity and extended hospital stays. This study aimed to assess the effects of an intravenous therapy regimen during postoperative day (POD) 0 to 2 in PD patients within ERAS. A retrospective interventional cohort study was conducted, and it involved all PD patients before and after implementation of ERAS (2009-2017). In the ERAS group, a targeted maintenance fluid regimen of 20 mL/kg/day with a sodium requirement of 0.5 mmoL/kg/day was administered. Outcome measures included the mmol of sodium and chloride administered, length of stay, and morbidity (postoperative pancreatic fistula, POPF; acute kidney injury, AKI; ileus). The study included 169 patients, with a mean age of 64 ± 11.3 years. Following implementation of the intravenous fluid therapy protocol, there was a significant reduction in chloride and sodium loading. However, in the multivariable analysis, chloride administered (mmoL/kg) did not independently influence the length of stay; or rates of POPF, ileus, or AKI (p > 0.05). The findings suggested that a postoperative intravenous fluid therapy regimen did not significantly impact morbidity. Notably, there was a trend towards reduced length of stay within an increasingly comorbid patient cohort. This targeted fluid regimen appears to be safe for PD patients within the ERAS program. Further prospective research is needed to explore this area.

Evaluation of aflatoxin M1 and nutritional content in Kosovo’s market cheese samples

The ubiquitous presence and potent carcinogenic effects of aflatoxins, a group of mycotoxins, pose a significant threat to global food safety, especially within the dairy sector. This research aimed to evaluate the prevalence and distribution of Aflatoxin M1 in diverse cheese varieties within Kosovo’s markets in 2022 and discern potential correlations with cheese types, processing conditions, and nutritional parameters to enhance understanding and ensure the safety of dairy products. In the latter half of 2022, a total of 93 different types of manufactured cheese samples from 15 different countries were analysed for Aflatoxin M1 toxin content using the enzyme-linked immunosorbent assay technique. The results of the research indicate that several countries have exceeded the concentration of 0.05 ug/kg for Aflatoxin M1, set as the maximum tolerable limit for milk and milk products in many countries. Notable, cheese samples from Albania exhibited substantially (p=0.000) higher levels of Aflatoxin M1 compared to other nations. The results showed that the Aflatoxin M1 concentration did not exhibit statistically significant variations based on the regulated total fat content (p=0.902), carbohydrate content (p=0.741), protein concentration (p=0.298), or salt content (p=0.122) within the cheese. The results demonstrated that Aflatoxin M1 levels were not significantly (p=0.926) affected by cheese consistency. While different starter cultures were associated with varying Aflatoxin M1 concentrations, these differences were not statistically significant (p=0.472). Similarly, ageing time did not exert a significant (p=0.691) impact on AFM1 levels, as concentrations remained relatively consistent across different ageing periods. These findings provide valuable insights into the variations in Aflatoxin M1 levels in cheese samples among different countries. They highlight the importance of regulatory measures and continuous monitoring to ensure food safety and adherence to maximum allowable limits

Effects of Polycyclic Aromatic Hydrocarbons on the Composition of the Soil Bacterial Communities in the Tidal Flat Wetlands of the Yellow River Delta of China.

Polycyclic aromatic hydrocarbons (PAHs) are pervasive organic pollutants in coastal ecosystems, especially in tidal flat wetlands. However, the mechanisms through which PAHs impact the soil bacterial communities of wetlands featuring a simple vegetation structure in the Yellow River Delta (China) remain largely unclear. In this study, we examined soil samples from two sites featuring a single vegetation type (Suaeda salsa) in the Yellow River Delta. Specifically, we investigated the impacts of PAHs on the diversity and composition of soil bacteria communities through high-throughput 16 S rRNA sequencing. PAHs significantly increased the soil organic carbon content but decreased the total phosphorus content (p = 0.02). PAH contamination notably reduced soil bacterial community α diversity (Shannon index) and β diversity. Furthermore, PAHs significantly altered the relative abundance of bacterial phyla, classes, and genera (p < 0.05). Specifically, PAHs increased the relative abundance of the bacterial phyla Acidobacteriota and Gemmatimonadota (p < 0.05), while decreasing the relative abundance of Bacteroidota, Desulfobacterota, and Firmicutes compared to the control wetland (p < 0.05). Moreover, PAHs and certain soil properties [total nitrogen (TN), soil organic carbon (SOC), total phosphorus (TP), and total salt (TS)] were identified as key parameters affecting the community of soil bacteria, with the abundance of specific bacteria being both negatively and positively affected by PAHs, SOC, and TN. In summary, our findings could facilitate the identification of existing environmental problems and offer insights for improving the protection and management of tidal flat wetland ecosystems in the Yellow River Delta of China.

Edible coating from VCO, iota-carrageenan and alginate blends for pindang fish preservation

This study aims to develop an edible coating based on virgin coconut oil (VCO) nanoemulsion, iota-carrageenan and alginate to prolong the shelf life of pindang (mildly salted cooked) fish products. The research involved three stages: material preparation, characterization and determination of factors and responses for experimental design; parameter optimization to achieve optimal conditions; and application and analysis of pre- and post-coating characteristics of pindang fish. The parameter ranges were 0.5–1.5% for alginate concentration, 0.5–1.5% for iota-carrageenan concentration and 0.5–1.0% for VCO nanoemulsion concentration. The result of this study was an optimized food coating solution that was clear and bright white in color. Pindang fish coated with this layer showed improved quality in terms of water content (48.46%), weight loss (0.39%), pH (5.84), total volatile base (47.01%), salt content (2.9%), appearance (7), texture (7) and slime (7). At the same time, the total bacterial count remained unchanged (8 log colony-forming units (CFU)/g), the mold count remained unchanged (5 log CFU/g) and the aroma and taste received a score of 6. Thus, this study successfully produced an optimized edible coating that can enhance the quality and extend the shelf life of pindang fish, making it suitable for broader market distribution.

The two salinity peaks mode of marine salt supply to coastal underground brine during a single tidal cycle

Seawater salt is constantly supplied from the marine environment to coastal underground brine deposits, meaning that brine has the potential for continuous extraction. There is currently a lack of information about the processes that drive the fluxes of seawater salt to underground brine deposits in tidal-driven brine mining areas. We chose the Yangkou salt field on the southern coast of Laizhou Bay, a brine mining area, as our study site. We monitored the spatial and temporal distribution of the underground brine reserve and the changes in water level and salinity in the mining area and adjacent tidal flats using electrical resistivity tomography and hydrogeological measurements. We monitored cross-sections along two survey lines and observed that the underground brine reserve receives a stable supply of seawater salt, and calculated that the rate of influx into the brine body in the mining area near the boundary of the precipitation funnel was 0.226−0.232 t/h. We calculated that a total salt flux of approximately 5.50 t enters the underground brine body every day through a 150 m long shoreline and a 1322.3 m2 window, which is sufficient to sustain the daily extraction of one brine well. During tidal cycles, there are two peaks in the salinity of the water supplied to the underground brine reserve, which means that the brine supply is from at least two high-salinity salt sources in different tidal stages. The first salinity peak occurs during the initial stage of the rising tide after seawater inundates the tidal flat. At this time, seawater, which is a solution and carries a large amount of evaporated salt, is transported into the brine layer through highly permeable areas or biological channels and replenishes the brine in the mining area. The second salinity peak occurs during the early stage of the falling tide. Influenced by hysteresis-driven tidal pumping, high-salinity brine from the lower intertidal zone is rapidly transported into the mining area, thereby increasing the salinity of the underground brine.

Impact of cellulose and lignin on restoration of vegetation and soil chemical properties for saline-alkali soil of songnen plain.

To explore the effects of cellulose and lignin on stimulating vegetation restoration and improving soil chemical properties in saline-alkali soil, a large area test was carried out, and 2 treatments were set up: T (cellulose and lignin+ Planted seeds) and CK (Planted seeds). In this study, the species, quantity, plant height, above-ground biomass, biodiversity of vegetation in the treated plots, the determination of soil chemical nutrient content, and the effect of cellulose and lignin on vegetation restoration in saline-alkali land were investigated. The results showed that: 1) Cellulose and lignin contributed to vegetation growth. Compared with CK treatment, plant height and aboveground biomass of T increased by 158.73% and 240.13%, respectively; 2) Cellulose and lignin improved soil structure, and soil porosity, and decreased soil compaction (21.95%); 3) Compared with CK treatment, T treatment decreased soil pH by 0.5 units, total salt content decreased by 30.95%, exchangeable Na+ decreased by 63.00%, and exchangeable sodium percentage (ESP) decreased by 61.51%. Furthermore, cellulose and lignin effectively improved the physical and chemical properties of saline-alkali soil, promoted the recovery of ecological environment in saline-alkali soil, and improved regional biodiversity, which will provide new methods for soil remediation and improvement in saline-alkali areas.

Characteristics of anion and cation in rhizosphere soil of saline grassland in North China under different nitrogen addition levels

We investigated the effects and mechanisms of nitrogen additions (0, 1, 2, 4, 8, 16, 24, 32 g N·m-2·a-1) on contents of anion and cation in rhizosphere soil, bulk soil, and mixed rhizosphere and bulk soil in the heavily salinized grassland in the agro-pastoral ecotone of North China. The results showed that pH of rhizosphere, mixed and bulk soils decreased significantly with the increases of nitrogen addition levels. Moreover, pH of three soil types under the 32 g N·m-2·a-1 treatment decreased by 1.2, 0.9, and 0.6, respectively, while pH of rhizosphere soil decreased by 0.44 compared with the bulk soil. Na+ content of rhizosphere, mixed and bulk soils significantly decreased, while the NO3- content significantly increased. The proportion of Na+ content in total soluble salt content in rhizosphere soil decreased by 14% and that in bulk soil decreased by 12% after the 32 g N·m-2·a-1 addition. NO3- content increased by 29% in rhizosphere soil and by 26% in bulk soil. There was significant negative correlation between pH and NO3- content, and significant positive correlation between pH and Na+ content. The total soluble salt content of rhizosphere soil under the 32 g N·m-2·a-1 treatment was significantly reduced by 31.5%. Collectedly, nitrogen deposition could reduce soil pH and total soluble salt content of rhizosphere soil and alleviate saline-alkali stress.

Research on Improvement of Light to Moderate Salinization and Alkalinization Farmland in Northeast China

The soil barrier factors currently present in Tuquan County, Northeast China, such as drought, waterlogging, stickiness, salt, alkalinity, and barrenness. This study chose to build a core demonstration area of 50 mu in Xinglongshan Village, Tuquan County. Seven improvement measures were adopted for soil improvement, including straw returning, alkaline amendment, desulfurization gypsum, organic fertilizer, deep tillage and deep loosening, furfural residue, and salt alkali tolerant variety screening. After adopting the above measures, the average soil pH value decreased by 0.4-0.9, the total salt content decreased by more than 10%, and the organic matter increased by more than 0.2 percentage points. The physical and chemical properties of the soil in the experimental area were significantly improved. These measures not only significantly improve the soil fertility of saline alkali farmland and increase the average grain yield by more than 15 percentage points, but also play a role in protecting farmland, thus forming a virtuous cycle.

Влияние фосфогипса и электролита травления стали на химические свойства почв рисовых чеков в условиях Ростовской области

Purpose: to study the effect of various ameliorants and their combinations, as well as leaching on paddy soil characteristics in laboratory conditions for determining the possibility of their further application. Materials and methods. In the course of the research, a soil reclamation survey of paddy fields in Rostov region was carried out. Soil samples analyzes were carried out in an environmental analytical laboratory using generally accepted methods. Soils with different chemistry, degrees of salinity and salinization, and different gypsum content were taken for the laboratory experiment. Based on the results of soil samples study, phosphogypsum, steel pickling electrolyte, and their combinations were used as ameliorants. Results. Leaching without ameliorants contributed to a total salt content decrease. On slightly saline soils of chloride-sulfate chemistry, their number decreased by 54 %, and on moderately saline soils of sulfate salinity by only 5 %. Ameliorants, especially phosphogypsum, increased their amount in non-saline soils by 5 times, and in slightly saline soils – by 2.7 times due to the accumulation of calcium sulfates. Their accumulation was not observed in moderately saline gypsum-containing soils. The steel pickling electrolyte reduced their quantity by 18 %, compared to the control. The soil absorption complex of non-saline and slightly saline soils was optimized, but in gypsum-containing soils it remained virtually unchanged. Conclusions. Laboratory experiments have shown that soils of chloride-sulfate salinity, having magnesium salinity and undersaturation with exchangeable calcium in the soil absorption complex, can be improved by using phosphogypsum and steel pickling electrolyte as an ameliorant, as they are the most accessible to land users. They promote the formation of gypsum, which accelerates the process of replacing exchangeable magnesium and sodium with calcium. Reclamation of highly gypsum-rich soils with a gypsum content of more than 20 % and easily soluble salts of more than 1.0 % using traditional methods is not very successful.