Total Salt Research Articles

Chemical characteristics and reactive transport of soil salt ions in frozen soil during the freeze and thaw period

Current researches on estimating soil salt movement during the freeze and thaw period are mainly based on total salt concentration, while ignoring the phase change of multi-component salts. In this study, the potential transport capability of soil water and salt ions in the frozen layer was investigated based on chemical characteristics and solute convection–diffusion theory. Field experiments were implemented to measure the change of total soil water, soil salt and its ion components. The soil water and salt content in liquid and solid phases were calculated by the FREZCHEM model, and then the movement of liquid soil water and soluble salt were simulated by the HYDRUS-1D model. The potential migration capability of soil water and salt components were then estimated by comparing the distribution profiles obtained by HYDRUS-1D and FREZCHEM. The results show that more than 74.5% of Cl, Na and SO4 were in liquid phase, which were less affected by precipitation-dissolution reaction and owned strong mitigation. The liquid soil water, soluble salt and salt ions in the frozen layer tended to decrease at the beginning of the freeze period and increase significantly at the end. The migration direction and quantity of various salt ions were different due to their concentration gradient and diffusion coefficient, causing the larger potential convection and dispersion quantity of Na+, Cl− and SO42- than those of Ca2+, Mg2+ and HCO3–. This study provides a new perspective for soil salt movement in frozen soil in agricultural areas with shallow groundwater table depth.

Low salt and biogenic amines fermented fish sauce (Mahyaveh) as potential functional food and ingredient

The response surface methodology was used to evaluate the influence of salt content (5–20%), fermentation temperature (25–50 °C), and fermentation time (20–80 days) on the chemical characteristics and histamine level of Iranian fish sauce (Mahyaveh) prepared from Anchovy fish. The results showed that salt had a significant quadratic effect on pH, total nitrogen, salt, and histamine content. The total nitrogen, pH, and histamine of fish sauce decreased with increasing salt concentration. Salt content had a significant linear effect on amino nitrogen. The amount of amino nitrogen decreased with increasing salt. Time had a positive quadratic effect on histamine and total nitrogen levels in fish sauce, whereas it had a positive linear effect on amino nitrogen level. In contrast, temperature showed a significant effect on the total nitrogen, histamine, salt, and pH of fish sauce (p < 0.05). As the temperature increased, total histamine decreased whereas nitrogen concentration increased. The predicted optimal conditions as determined by Response Surface Methodology were salt content of 12.5%, fermentation temperature of 39.15 °C, and fermentation time of 39.79 days. Therefore, high quality Iranian fish sauce can be produced with low salt and histamine content as a potential functional food and ingredient.

Effects of a smartphone app-based diet and physical activity program for men living with HIV who have dyslipidemia: A pilot randomized controlled trial.

People living with HIV are at a high risk for cardiovascular disease owing to antiretroviral therapy use and chronic inflammation. There is limited evidence on the evaluation of serum lipid levels through lifestyle modification. This study aims to evaluate the effect of a smartphone application-based diet and exercise improvement program on men living with HIV and dyslipidemia. This was a randomized controlled trial recruiting Japanese men living with HIV who have dyslipidemia: intervention group (n = 19) and control group (n = 19). The intervention group received a third individual guidance session during the 6-month intervention and was encouraged to record their diet on a smartphone application. An intention-to-treat analysis of the results was conducted. The intervention group showed significantly reduced change in low-density lipoprotein levels compared to the control group (-4.00 ± 20.2 mg/dL vs. 10.11 ± 21.1 mg/dL) (p = .042) from baseline to 6 months post-intervention. No significant differences were found in other serum lipid levels. Abdominal circumference decreased significantly in the intervention group (p = .048) from baseline to 6 months post-intervention. Total energy, protein, carbohydrate, fat, and salt intake, dietary and physical activity behavior change stages and social support, dietary self-efficacy, and loneliness significantly improved in the intervention group (p < .05) from baseline to 6 months post-intervention. A diet and physical activity improvement program using a smartphone application based on Japanese-specific health guidance may reduce low-density lipoprotein cholesterol levels in this population. Further sample expansion and examination of long-term effects are needed.

Coupled modelling of artificial freezing along clay-sand interface under seepage flow conditions

The artificial freezing in the clay-sand stratum under seepage flow conditions involves the hydro-ice-salt-crystalline-thermal-mechanical coupling process. A theoretical model is derived to investigate the influences of water seepage on the freezing process in the clay-sand stratum. The good agreements between the results from the theoretical model and laboratory tests in the literature verified the accuracy of the proposed model. Parametric studies are conducted to investigate the influences of the seepage velocities and temperature gradients on the spatial distributions. It is found that the ice contents, crystalline salt contents and adsorbed salt contents distribution profiles in the clay-sand stratum are nonlinearly distributed with a cliff distribution curve existing on their interface. The crystalline salt contents in the clay layer are higher than those in the sand layer due to the influence of water seepage and heat transfer. The adsorbed salt contents in the frozen area account for 2% of the total salt contents, but those in the unfrozen area account for 8% of the total salt contents. Due to the volume expansion caused by the soil skeleton deformation, thickness of fractional ice, ice frost heave deformation and salt swelling deformation, the soil deformation distribution curves in the clay-sand stratum are in a bilinear shape.

Evaluation of Dispersion for Soil Properties from Faw City- Southern Iraq

Four boreholes were drilled in four different places of the AL- Faw city using a hand auger, disturbed samples were collected at depths of 0.5 and 1.5 meters. The soil of the study area was determined by classification tests to be silty clay, CL-type soil in the Unifined Classification System of Soils. Soil dispersion tests such as the Crumb test, chemical analysis and XRD tests were conducted, and the results of crumb test showed that the soil of the study area was low dispersive from grade 2 except for the fourth site was a non-dispersive soil. The values of Total Salts Dissolved (TDS) in the pore water of the soil, was determined by estimating the total concentration of dissolved cations (Na, K, Ca and Mg) .The ETDA titration technique (for Ca and Mg) and the flame photometer were used to test this pore water (for Na and K), and it showed that the soil of the study area in the four sites within the C zone represented the Intermediate dispersive soil classification chart, and the results from Sodium Absorption Ratio (SAR) values showed that the soil in the area was dispersive.&#x0D; The XRD data showed that the minerals quartz, calcite, dolomite, and clay made up the majority of the soil samples. The principal clay minerals included Smectite (Montmorillonite), Palygorskite and Kaolinite. The results of the Total dissolved salts test showed a variety of the Crumb test for a difference in the soil content of mineral and chemical components. It is necessary to conduct further research on the XRD analysis with detailed interpretation of the minerals present, the importance of clay mineral types like Smectite should be assessed. The study of dispersion processes, the identification and classification of soils from specific tests and the identification of soils are the main objectives of this research.

Exploring the Macroscopic Properties of Humic Substances Using Modeling and Molecular Simulations

Soil organic matter (SOM) is composed of a complex and heterogeneous mixture of organic compounds, which poses a challenge in understanding it on an atomistic level. Based on the progress of molecular dynamics simulations and our efforts to create molecular systems that resemble SOM, in this work, we expanded our knowledge of SOM through the use of humic substances (HSs). Specifically, we studied the standardized samples of HS of the International Humic Substances Society (IHSS). This society provided the elemental and organic composition used as input parameters for our Vienna Soil Organic Matter Modeler 2 (VSOMM2). We modeled and simulated different HS samples from various sources, including soil, peat, leonardite, and blackwater river. In order to compare between different HS, we reduced the organic composition information to two principal components, which are associated principally with the amount of carboxyl and aromatic groups in the HS, denominated as PCacid and PCarom, respectively. We performed a plethora of analyses to characterize the structure and dynamics of the systems, including the total potential energy, density, diffusion, preferential solvation, hydrogen bonds, and salt bridges. In general terms, at the water content value of 0.2, we observed that most properties depend on the carboxyl group protonation state. The Coulombic interactions from this ionic specie and the interaction with cations determine the overall behavior of the studied systems. Furthermore, the type of cations and the pH influence those properties. This study exemplifies the importance of molecular dynamics to explain macroscopic properties from the structure and dynamics of the molecules modeled, such as the interaction network, i.e., hydrogen bonds or salt bridges of molecules presented in the system and their mobility.

Consumption of meat and dairy substitute products amongst vegans, vegetarians and pescatarians.

An increasing number of people adhere to plant-based diets, and the market for plant-based meat and dairy substitute products has been expanding rapidly. To examine total intake of macronutrients and salt in a sample of Norwegian vegans, vegetarians and pescatarians; the consumption frequency of plant-based meat and dairy substitutes and raw ingredients used in these products; and the contribution to total macronutrient and salt intake from these products. A cross-sectional design using single 24-h dietary recall to assess the intake of macronutrients, salt and substitute products that the participants (n = 158 Norway residents [age 18-60 years]: vegans [n = 83]; vegetarians [n = 47]; pescatarians [n = 28]) consumed. The chi-square test with pairwise comparisons and the Kruskal-Wallis test with post hoc test were used to compare differences between diet groups. Macronutrient and salt intake were assessed relative to the Nordic Nutrition Recommendations (NNR). Dietary macronutrient intake fell within NNR recommendations, with a favourable distribution of fatty acids and high levels of dietary fibre. Most of the vegans (90%), vegetarians (68%) and pescatarians (64%) consumed meat or dairy substitutes. The main raw ingredient in the substitute products was soy, followed by oats and peas. Overall, substitute products contributed to 12% of total energy and 16% of total salt intake. The substitute products contributed to higher saturated fatty acid (SFA) intake amongst vegans (27% of total SFA intake) compared with vegetarians (10%) and pescatarians (8%). Moreover, substitute products contributed to higher protein intake in vegans (19%) compared with pescatarians (7%). Most participants consumed meat or dairy substitute products, suggesting that these products are included regularly in Norwegian plant-based diets. Furthermore, substitute products may contribute to dietary fat, SFA and protein intake amongst vegans.

Impact of Salinity and Sodicity on Crop Growth and Physicochemical Properties of Some Aridisol and Vertisol Soils in Sudan: A Review

Comprehensive field and laboratory studies were undertaken toinvestigate the performance of some crops on salt-affected soils in Sudan.To separate salinity and sodicity indicators some laboratory studies wereconducted on soils equilibrated with mixed NaCl-CaCl 2 solutions. Therelative hydraulic conductivity (RHC) or diffusivity increased withincrease in total salt concentration (C) and decrease in exchangeablesodium percentage (ESP). A dispersion index (DI), a swelling index (SI),shrinkage volume and modulus of rupture increased with increase in ESPand decrease in C. The data showed a highly significant linear decrease inRHC with increase in DI or SI. The threshold salt concentrations (THC),which gave 75% of the highest RHC, and ESP relationships, wereobtained for samples from an Aridisol and a Vertisol soils.. The salinityprofile obtained after intermittent leaching with water suggested thepresence of a desalinized zone followed by a salinized one with thehighest salt concentration below the wetting front. The depth of thedesalinized zone increased significantly with increase of the amount ofwater stored (r2 = 0.968) and the length of the wetting front (r2 = 0.974).Soil amendments promoted salt leaching in the following order: Sand&gt;chicken manure&gt; water hyacinth&gt; gypsum&gt; dry sewage&gt; farm yardmanure&gt; control. Cumulative evaporation (E) for the various amendments

Spatial heterogeneity of soil properties of recreational areas of Volgograd

The article presents the developed soil maps and maps of spatial variability of soil properties (pH, total salt and carbonate content, organic carbon, density) in some recreational areas of Volgograd. The anthropogenic soils in the studied recreational areas include various urbostratozems (Urbic Technosols (Transportic)), Ekranic Technosols (Transportic), as well as quasizems (Phaeozems (Tehnic)), among the agrogenic ones – accumulation-carbonate agrozems (Cambisols (Aric, Protocalcic). Natural soils are represented by light and dark humus soils, chestnut soils, solonetz, as well as stratozems and psammozems. According to the data of isolinear mapping, it was found that acid-alkaline properties of soils of green zones vary from slightly alkaline to alkaline depending on the soil horizon and anthropogenic load. The mapping did not reveal salinization of the upper 0–30 cm layer. Values of organic carbon vary greatly (1–10%) and are conditioned by the presence or absence of meliorative artificial layers, as well as by the character of territory use. The content of calcium carbonates in the upper 30 cm is small and varies from 0.7 to 5%. It is established that the physical properties (density) directly depend on the level of anthropogenic load, increasing in footpaths and lawns. Spatial assessment of the properties of urban soils is important for identifying areas with an excess or on the contrary – low content of certain chemical and physical indicators for the planning of landscaping and gardening of urban areas.

Physicochemical properties and risk assessment of perishable waste primary products

Fertilization has become one of the most important ways to recycle perishable waste. In order to reveal the effect of the nutrient of the perishable waste primary products on the market and the possible impact of their application, 136 perishable waste primary products were sampled in nine cities in Zhejiang province, China. The result shows that these products have high nutrient content (average nutrient content was 5.00%). However, the conductivity (7.19 mS/cm) total soluble salt content (12.07%), and grease content (5.99%) were too high. The excessive salt and grease may cause harm to soil and crops, and become the main limiting factors for the fertilizer utilization of perishable waste. Heavy metal content of most of the samples met current commercial organic fertilizer standards, except that lead and chromium content of some samples exceeded the limit standard. Toluene, ethylbenzene, m & p-xylene were generally detected in the samples. These toxic and harmful substances have brought risks to the safe use of perishable waste into fertilizers.

Effects of the Salt-Tolerant Gramineous Forage Echinochloa frumentacea on Biological Improvement and Crop Productivity in Saline–Alkali Land on the Hetao Ningxia Plain in China

Biological improvement is a sustainable approach for saline–alkali land amelioration and utilization. Echinochloa frumentacea (Roxb.) link is a salt-tolerant gramineous forage, which plays an important role in improving saline–alkali land. The Hetao Ningxia Plain is located in the upper–middle reaches of the Yellow River with a large area of saline–alkali soil, where E. frumentacea has potential applications for improving saline–alkali land. Three experiments were conducted on saline–alkali land in Pingluo County, Ningxia, including soil-leaching experiments in pots as well as monoculture or intercropping experiments involving E. frumentacea in fields. The results showed that: (1) E. frumentacea had a strong leaching ability of Na+ and SO42− in saline–alkali soil. (2) The planting of E. frumentacea decreased soil pH and total salt; enhanced the available N, P and K; and increased plant height, stem thickness and yields compared with the control. (3) The diversity of soil bacteria and land use efficiency could be improved by the intercropping of E. frumentacea with legume forages. Overall, E. frumentacea is an important pioneer species of biological improvement for the sustainable utilization of secondary saline–alkali land produced by irrigation around the world.

Simplistic determination of the membrane pore charge density in presence of mixture of electrolytes

Membrane pore charge density (Xd) is an effective but non-measurable parameter for determining the performance of low cut-off ultrafiltration (LCUF) and nanofiltration (NF) membranes. Xd along with the physicochemical properties of the solution determines the membrane zeta potential. These properties include the solution pH, ionic strength as well as the ratio and nature of electrolytes in the solution. Hence, with the prior knowledge of the solution physicochemical properties and the zeta potential, determination of Xd is possible. In this study, the effect of binary mixture of electrolytes, i.e., NaCl/Na2SO4 on the membrane zeta potential was investigated for different solution pH (3–9) as well as the total salt concentration (2–10 g L−1). An empirical correlation between Xd and the other experimentally measurable parameters was developed. Salt rejection experiments were carried out with the above mentioned combinations of pH and total salt concentration along with different weight ratios of NaCl/Na2SO4 namely, 100:0, 90:10, 70:30, 50:50 and 0:100 for six LCUF membranes. For PAN PDA/PEI 12 membrane, at pH 7 and 2 g L−1 of total salt concentration, the rejection of divalent anion (SO42−) was increased from 60% to 75.3%, for monovalent cation (Na+), it was increased from 33% to 41.2% with the concentration of Na2SO4. However, the corresponding rejection of monovalent anion (Cl−) was decreased from 33% to 16.1%. For each of the experimental condition, Xd obtained from the Donnan Steric Pore Model (DSPM) solution was correlated with the zeta potential (ζ) and weight fraction of divalent salt (r) as: Xd=a+br+cζ. The effect of the solution pH and ionic strength is included in the membrane zeta potential. The correlation was successfully tested for the commercial membranes in predictive mode. The empirical correlation proposed in this paper acts as a useful tool to determine Xd for amine based LCUF membranes. This helps to predict the membrane performance for real life desalination treatment without performing a series of rejection experiments.

Physicochemical Properties, Amino Acid Composition and Volatile Components of Fermented Fish (Pla-ra) Accelerated by Starter Cultures

Fermented striped snake-head fish, known as Pla-ra, is a popular traditional food that is eaten throughout Thailand. Lactic acid bacteria (LAB) are found as the dominant microorganisms in many fermented fish products. The primary role of LAB is to ferment the available carbohydrates, and thereby causes a decrease in pH. The combination of low pH and organic acids (mainly lactic acid) are the main preservative factors found in fermented fish products. The purpose of this study was to determine the change in physicochemical properties, amino acid composition, and active volatile compounds of Pla-ra, by adding halophilic bacteria and LAB into the fish fermentation. The results revealed that the pH of the 8 Pla-ra treatments were found between 5.33 - 5.63, and the salt content of all Pla-ra treatments, ranged from 20.60 to 22.28 %. The increase in total acidity and the degree of hydrolysis (DH), is generally accompanied by a decrease in pH. The FMP treatment had the highest total acidity, protein, salt, DH and amino acid contents, but had the lowest pH. The important amino acids in all 8 Pla-ra treatments were glutamic acid, lysine, and leucine. There were 43 volatile compounds detected in Pla-ra, and the 7 prime ones were aldehyde, alcohol, ester, furan, pyrazine, sulfur, and ketone. Micrococcus sp., Bacillus subtilis and Pediococcus halophilus strains, and roasted rice powder were added to the fish fermentation, which greatly enhanced the flavour and volatile compounds in Pla-ra. HIGHLIGHTS Halophilic bacteria and lactic acid bacteria (LAB) added into the striped snake-head fish or Pla-Chon fermentation were greatly enhanced the flavour and volatile compounds in Pla-ra Striped snake-head fish fermentation can be accelerated by the addition of halophilic bacteria and LAB, and roasted rice powder 9 Non-essential amino acids and 9 essential amino acids were detected in Pla-ra Dominant amino acids in all 8 Pla-ra treatments were glutamic acid, lysine, and leucine 43 Volatile compounds were detected in Pla-ra with aldehyde, alcohol, ester, furan, pyrazine, sulfur, and ketone were the 7 prime ones GRAPHICAL ABSTRACT

Iodine Availability through Iodized Salt in Portugal: 2010-2021 Sales Evolution and Distribution.

Salt iodization programs are considered the most cost-effective measures to ensure adequate iodine intake in iodine-deficient populations. Portuguese women of childbearing age and pregnant women were reported to be iodine-deficient, which led the health authorities, in 2013, to issue a recommendation for iodine supplementation during preconception, pregnancy and lactation. In the same year, iodized salt became mandatory in school canteens. Of note, no regulation or specific programs targeting the general population, or the impact of iodized salt availability in retailers, are known. The present study analyzed iodized salt supermarket sales from 2010 to 2021 from a major retailer, identifying the proportion of iodized salt in total salt sales and its distribution in mainland Portugal. Data on iodine content were collected through the nutritional label information. Of a total of 33 salt products identified, 3 were iodized (9%). From 2010 to 2021, the weighted sales of iodized salt presented a growing tendency, reaching the maximum of 10.9% of total sales (coarse plus fine salt) in 2021. Iodized salt reached a maximum of 11.6% of total coarse salt in 2021, a maximum of 2.4% of the total fine salt in 2018. The overall sales of iodized salt and their contribution to iodine intake are extremely low, prompting additional studies to understand the consumer's choice and awareness of the benefits of iodized salt.

Feature and mechanism analysis of dispersive soil disintegration impacted by soil water content, density, and salinity

AbstractDispersive soil has caused innumerable water‐induced erosion failures of earthen structures in arid regions up to now, among which disintegration, as the first response process, is commonly deemed as the primary inducement but with inadequate understanding. In this study, the disintegration characteristics of a compacted dispersive lean clay with sand were investigated by carrying out laboratory disintegration tests under a water immersion regime. Soil mass water content (ω), dry density (ρd) and total soluble salt content (η) were considered. Results suggest that for dispersive soil, (1) the disintegration process exhibited two distinct modes, which was divided by the ω near the optimum water content; (2) higher ρd delayed disintegration monotonously; (3) increasing η first weakened and then enhanced the disintegration, in which pattern the η at the inflection point increased with increasing ρd, showing a density dependence. Evolutions of representative soil morphology were illustrated. More importantly, the underlying influential mechanism of ω and η to disintegration were elaborated emphatically: (1) the initial clay dispersion level, soil consistency change, and conceptual “constraint force” exerted by soil matric suction jointly determine the disintegration modes; (2) increasing η makes the soil pore solution concentration higher and microstructure simpler, competition between the two leads to nonmonotonic change patterns of disintegration completion time (Td) and defined velocity (Vd); the interactive effect of ρd and η manifests that η produces an additional influence on the base of microstructure created by ρd. Finally, the grey relation entropy analysis was introduced to evaluate the contributions of the three test variables to Td and Vd. The obtained results and proposed perspectives are expected to be conducive to a deeper comprehension of the same or relevant behaviours of dispersive soils in the presence of water, so as to provide new insights for the targeted prevention and control of dispersive soil catastrophes.Highlights Disintegration of dispersive soil shows two distinct water content‐dependent modes. Soil salinity has a two phase impact on disintegration of dispersive soil. Dry density and soil salinity interact affecting disintegration. Relationship between soil dispersion and disintegration is elaborated.

Prospective cohort study on potato intake and mortality from cardiovascular diseases: the Japan Collaborative Cohort Study (JACC study).

The association between potato intake and risk of cardiovascular diseases is unknown. This study aimed to examine the association between potatoes intake and mortality from stroke and coronary heart disease among Japanese. The study included 74,750 participants of the Japan Collaborative Cohort Study, aged 40-79, who were initially free of cardiovascular diseases or cancer at baseline (1988-1990) and provided information on their potato intake. Hazard ratios and 95% confidence intervals were estimated by fitting a Cox proportional hazards model according to the frequency of potatoes intake (0, 0.4, 1.5, 3.5 and 7 servings per week) adjusting for geographic location, age, body mass index, drinking status, smoking status, perceived mental stress, education level, walking time, dietary intakes of total energy, meat, fish, vegetables, fruit, dairy products, cakes, and salt. Over a median of 19.2years of follow-up, 4908 deaths from cardiovascular diseases were identified: 1019 from coronary heart diseases and 2153 from strokes (738 ischemic strokes and 495 hemorrhagic strokes). After adjustment for potential confounding factors, the hazard ratio of mortality from cardiovascular diseases for daily potato intake compared with no potato intake was 0.82 (95% confidence interval: 0.70, 0.95) among women, and 1.01 (0.88, 1.16) among men. Among women, the multivariable hazard ratios were 0.67 (0.48, 0.96) for coronary heart disease, 0.83 (0.66-1.05) for total stroke, 0.70 (0.43-1.15) for hemorrhagic stroke, and 0.75 (0.49-1.13) for ischemic stroke. We found an inverse association of potato intake with mortality from total cardiovascular diseases, especially that from coronary heart disease, among Japanese women. To our knowledge, this is the first report to show an inverse association between potato intake and total cardiovascular diseases.

Geotechnical Properties of Soil Slopes of the Great Musaiyab Project, Babylon, Middle of Iraq

The research deals with the study of the geotechnical properties of the soil of the banks of the Great Musaiyab Project in the province of Babylon in central Iraq, as it includes the study of the physical, chemical, engineering, and mineral properties. The results of the physical tests showed that the grain size distribution of silt was higher than that of clay and sand at a rate of 36.91%, that of clay 30.9% and that of sand 31.06%, and the average of the maximum dry density values was 1.9125g/cm3. The average specific weight was 2.69, and the results of chemical tests showed that the percentage of carbonates (17.98%, percentage of gypsum 0.7075%, the percentage of sulfates 0.3282%, percentage of organic substances 2.7435%, and the percentage of total salts soluble 1.7193%. The results of the engineering tests indicated that the direct shear test showed that the cohesion value ranged between 0 and 50 KN/m2, the internal friction angle ranged between 7 and 37, and the unconfined pressure resistance ratio ranged between 3 and 48 KN/m2. While the results of the metal properties indicated using ray diffraction XRD, which showed the mineral content of the soil, as it consisted mainly of calcite, quartz, and feldspar, in addition to clay minerals.

Effect of Deep Straw Return under Saline Conditions on Soil Nutrient and Maize Growth in Saline–Alkali Land

To clarify the effect of tillage methods on saline–alkali land improvement and maize growth in cropland salinized to different degrees, we set up two treatments (shallow rotation (15 cm depth; CK) and deep straw return (35 cm depth; DPR)) in land characterized by three different salinization degrees and analyzed the effects of the two treatments on soil nutrient content, salinity index, chlorophyll fluorescence, growth status, and yield at three salinization levels. The results show that (1) compared with CK, alkaline N, total N, Olsen P, exchangeable K, and organic matter in saline soils were all significantly improved, and total salt and pH values were reduced by 34.01–50.79% and 2.56–7.54%, respectively, under deep straw return conditions, representing the largest values in moderately saline–alkali land. (2) Compared with CK, chlorophyll fluorescence was significantly improved, and maximum photochemical efficiency (Fv/Fm), photochemical quenching (qP), and effective quantum yield of PSII (ΦPSII) were significantly increased by 8.09–15.41%, 9.13–17.93%, and 38.79–70.83% following deep straw return treatment; these increases were the largest ones observed in moderately saline–alkali land. (3) Deep straw return promoted the growth of maize and significantly increased the yield of maize. Plant height, leaf area index, and yield increased the most in moderately saline–alkali land and increased by 6.84–21.79%, 0.59–2.28 units, and 12.78–28.07%, respectively. The yield increased by 33.89 %, which was mainly due to the increase in 1000-grain weight. The results provide a theoretical basis for taking straw return measures to improve soil and increase maize yield in saline–alkali land.

Suitability of the Lower Zab River Sediments for Concrete Works / Southwest of Kirkuk - Northern Iraq

An Engineering study was carried out for five stations in the Lower Zab basin, southwest of Kirkuk, to determine the viability of the Quaternary age sediments for concrete works. The geotechnical evaluation results included that the coarse aggregate's grain size analysis is identical to the gradient class (63.0 mm) according to the [1] classification. As for the gradation of fine aggregate for the sediments of the study area, the results of the granular gradient of the samples after matching them with the limits of AASHTO specification showed that they are identical to the specification with slight differences on some sieves. The elongation and flatness tests showed that the highest percentage of the longitudinal shape is (19.2%) and flat-shaped particles is (28.8%), within permissible limits according to British standard [2], the specific gravity for coarse aggregate was between (2.60 - 2.64) and saturated specific gravity (2.61 - 2.65), and the values of specific weight for fine soil ranged from (2.72 - 2.64) which is suitable for use in concrete works. The results of the laboratory test of the durability tests - The Los Angeles test for the samples showed that the highest percentage for weight loss was (20%), which is suitable for use in the concrete according to the Iraqi standard [3], the results of the laboratory test for stability showed that the percentage of weight loss for coarse aggregate (gravel) by the effect of sodium sulfate solution and for the number of 5 cycles of the samples ranged between (8.3% - 4.1%), which is valid for use in concrete works according to the American specification [4]. The results of the resistance tests - the point load test for stations (S1, S3, S4) within the classification range of very strong - extremely strong, and the two stations (S2, S5) within the class strong - very strong - extremely strong compared to the classification of [5], and they are good for concrete works. It was found from the results of the chemical tests the gypsum content, organic matter content, Total soluble salts, and the sulfate content of the samples of the study area are suitable to for concrete works according to British Standard [6], which is suitable for concrete works, testing the compressive strength of concrete cubes ranged between (24.93 - 18.22 MPa) for age seven days and ranged between (33.02 - 29.76 MPa) for 28 days for reference mixture, Which is (4:2:1 by weight). According to the Iraqi standard specification [7], the compressive strength values of the samples are suitable for regular unreinforced concrete, and in comparison with [8] classification, it was apparent that the concrete produced is of moderate endurance. And suitable for concrete works According to [9].

Reinforced soil salinization with distance along the river: A case study of the Yellow River Basin

Clarifying the relationship between salt-affected soils and their adjacent river systems is critical to address the challenges posed by soil salinization on agricultural production. Among the various biophysical and land management factors linked to soil salinization, few studies have investigated the importance of the distance along the river. Based on the Hetao Irrigation District of the Yellow River Basin, we collected 5314 soil samples and analyzed 17 soil parameters to explore the relationship between salt-affected soils and their distance along the river. Soil salinization was reinforced by the distance along the river, as a trade-off between soil ion accumulation and nutrient regulation. Soil total water-soluble salt content increased by 16.4 mg kg−1 every kilometer, likely due to ions leaching from the soils upstream and partially accumulating in the soils downstream, especially for Cl-, SO42-, and Na+. Greater input and less solubility of Ca2+ based soil amendments, phosphorus fertilizers, and organic materials on the less salt-affected soils upstream may explain the declines in soil Ca2+, available phosphorus, and soil organic matter with distance along the river. With every kilometer along the river, soil exchangeable sodium and cation exchange capacity increased by 8.89 × 10−4 and 1.26 × 10−2 cmol kg−1, respectively, which led to an increase in soil exchangeable sodium percentage by 9.59 × 10−5. The increase in soil exchangeable sodium along the river was mainly due to Na+ accumulation, while soil cation exchange capacity was regulated by soil organic matter and total nitrogen. Soil pH increased by 1.21 × 10−3 per kilometer along the river, associated with the decrease of soil organic matter. Future saline soil amelioration and reutilization initiatives at regional scales may be improved by accounting for the changes in soil physicochemical properties resulting from the distance along the river.