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Nakhon Ratchasima Province faces significant challenges due to saline soil and water, resulting from natural salt rock deposits and salt mining activities. This study investigates the physicochemical properties, salinity distribution, and surface water quality in Non Thai and Phra Thong Kham District. A total of 75 samples were collected, with 48 from Non Thai and 27 from Phra Thong Kham. The analysis focused on properties such as temperature, electrical conductivity (EC), pH, total dissolved solids (TDS), salinity, chloride, sodium, calcium, and magnesium. Water quality was assessed using standards from the Thai Department of Health and the World Health Organization. Additionally, the Sodium Adsorption Ratio (SAR) was employed to evaluate irrigation suitability, and ArcGIS 10.5 was utilized to map salinity and water quality distribution. Results indicated that surface water pH remained relatively neutral and within acceptable limits. However, salinity levels varied from 0.5 to 30 ppt, indicating brackish to saline conditions. In several areas, concentrations of salinity, sodium, and chloride exceeded standard limits. Factors such as proximity to salt mines, water flow direction, lower terrain, and smaller reservoirs were linked to increased salinity, with Phang Thiam Subdistrict in Phra Thong Kham District showing the highest levels. The SAR index further indicated that water quality in Phra Thong Kham was unsuitable for domestic use and irrigation, unlike Non Thai. Further research in other salt mine areas are essential for a deeper understanding of salinity distribution, which is crucial for assessing risks and making informed decisions to protect public health and the environment. [ABSTRACT FROM AUTHOR]

Fluoride and nitrate contamination in groundwater is a global concern due to their toxicity and associated negative health effects. This study incorporated a comprehensive methodology, including hydrogeochemical analysis, drinking and irrigation water quality assessment, source apportionment, and health risk estimation of groundwater fluoride and nitrate in a lithium ore deposit basin in western Serbia. Groundwater major ion hydrogeochemistry was governed by water–rock interactions, with Ca-Mg-HCO3 identified as the predominant groundwater type. The entropy-weighted water quality index (EWQI), sodium adsorption ratio (SAR), and sodium percentage (%Na) revealed that 95% of the samples were of excellent to good quality for both drinking and irrigation. Moreover, the results showed that fluorides were of geogenic origin, whereas nitrates originated from agricultural activities. Although the fluoride and nitrate levels in groundwater were relatively low, averaging 1.0 mg/L and 11.1 mg/L, respectively, the results of the health risk assessment revealed that the ingestion of such groundwater can still lead to non-cancerous diseases. The threshold of one for the hazard index was exceeded in 15% and 35% of the samples for adults and children, respectively. Children were more vulnerable to non-carcinogenic risk, with fluorides being the primary contributing factor. The study outcomes can serve as a reference for other lithium-bearing ore areas and guide the management of regional groundwater resources. [ABSTRACT FROM AUTHOR]

Areas with a dry climate constitute about 15% of the Earth's surface, so groundwater can be considered a safe alternative available for people who are living in these areas. Groundwater has special advantages compared to surface water in terms of spatiotemporal presence, high stability, easy access, and often of high quality and capable of resisting pollution and could be the alternative to solve the problem of water shortage.The current study evaluated Irrigation Water Quality Indices (WQIs) as well as the predicting of GIS maps to evaluate groundwater resources for agricultural uses in Al-Najaf city. 24 samples were taken from the existing wells and examined for the characteristics relating the groundwater quality. Total hardness (TH), Sodium Adsorption Ratio (SAR), Residual Sodium Carbonate (RSC), Soluble Sodium Percentage (SSP), Magnesium Hazard (MH), Permeability Index (PI), and Kelley's Index (KI) were among the irrigation indices that were assessed and evaluated. The results showed that 95.8% of sites fall within the region of extremely high salinity danger /low sodium, and 4.2% of sites fall onto the medium sodium water class, Concerning SSP and RSC all samples are considered of good quality, 95.8% of samples are suitable for irrigation based on Kelly's Ratio index, while only 4.2% regarded unsuitable. The final WQIs values were exported to the ArcMap software to create the final study area's water quality indices maps. Conducting spatial variability of groundwater quality is essential for making reliable groundwater quality interpretations and for making accurate predictions of quality at any particular site, there must be a continuous salinity and contaminants concentrations checking up calculations in case there were a need for groundwater desalination process.

Nakhon Ratchasima Province faces significant challenges due to saline soil and water, resulting from natural salt rock deposits and salt mining activities. This study investigates the physicochemical properties, salinity distribution, and surface water quality in Non Thai and Phra Thong Kham District. A total of 75 samples were collected, with 48 from Non Thai and 27 from Phra Thong Kham. The analysis focused on properties such as temperature, electrical conductivity (EC), pH, total dissolved solids (TDS), salinity, chloride, sodium, calcium, and magnesium. Water quality was assessed using standards from the Thai Department of Health and the World Health Organization. Additionally, the Sodium Adsorption Ratio (SAR) was employed to evaluate irrigation suitability, and ArcGIS 10.5 was utilized to map salinity and water quality distribution. Results indicated that surface water pH remained relatively neutral and within acceptable limits. However, salinity levels varied from 0.5 to 30 ppt, indicating brackish to saline conditions. In several areas, concentrations of salinity, sodium, and chloride exceeded standard limits. Factors such as proximity to salt mines, water flow direction, lower terrain, and smaller reservoirs were linked to increased salinity, with Phang Thiam Subdistrict in Phra Thong Kham District showing the highest levels. The SAR index further indicated that water quality in Phra Thong Kham was unsuitable for domestic use and irrigation, unlike Non Thai. Further research in other salt mine areas are essential for a deeper understanding of salinity distribution, which is crucial for assessing risks and making informed decisions to protect public health and the environment.

This study investigates the feasibility of utilizing drainage water for reclamation of saline and sodic soils in the Dosalagh plain of Khuzestan province, Iran. With significant drainage water generated in the region's irrigation networks, repurposing it for soil reclamation emerges is a low-risk strategy. Leaching, a practical technique for soil desalination, was examined using the double ring method at depths up to 150 cm. Four water qualities (electrical conductivities of 2.12, 7, 25 and 40 dS m−1) and depths (0, 25, 50 and 75 cm) were tested, with intermittent leaching over three cycles. Results indicate a substantial reduction in electrical conductivity (117.7 to 29 dS m−1) and sodium content (1415.9 to 39.83 mEq L−1) at the 0-25 cm depth with drainage water incorporation. The study highlights the beneficial impact on soil quality, emphasizing decreased sodium content, sodium adsorption ratio, and electrical conductivity. Overall, reusing drainage water proves advantageous for soils with high salinity levels, showcasing its potential for sustainable soil management in saline regions. This research underscores the importance of effective drainage water management for soil reclamation and agricultural sustainability in arid regions like Khuzestan province. HIGHLIGHTS Soil electrical conductivity (EC) decreased by increasing the depth of leaching water.; By increasing the depth of water in the leaching process, the amount of soil sodium and chloride decreased.; The combination of saline drainage water and non-saline river water is suitable for irrigation and reducing soil salinity.; The amount of EC reduction was more than exchangeable sodium percentage reduction.;

Water pollution has become a global concern, particularly due to the escalating demand for water. This study focuses on evaluating groundwater quality for irrigation purposes in the Sidi Allal Tazi region, Morocco, utilizing the irrigation water quality index. Indices like total disolved solids, sodium percentage, Kelly’s ratio, and sodium adsorption ratio suggested that 22–66% of the samples were unsuitable for irrigation, whereas primality index, magnesium ratio, and residual sodium carbonate indices classified 91–100% of the wells as appropriate for irrigation in the Sidi Allal region. The values of irrigation water quality index, about, 29% of the wells were categorized as having severe restrictions, 7% as high restrictions, 22.2% as moderate restrictions, and 42.2% as low restrictions for irrigation in study area, it indicating that more than half of the area has wells suitable for irrigation. These results suggest that the majority of wells in the Sidi Allal region is appropriate for irrigation purposes. This research further suggests implementing suitable di-chlorination, sodium reduction, and denitrification methods to enhance the quality of ground-water for irrigation use.

Quaking aspen (Populus tremuloides Michx.) landscapes are valued for their biodiversity, water retention, fire mitigation, aesthetics, and recreation opportunities. Across North America, some aspen populations are experiencing population declines as they face uninhibited ungulate browsing, drought, fire suppression, insects, disease, and inappropriate management. Increased human development and recreational use within aspen landscapes can serve as additive stressors, though there is a dearth of literature examining these elements. At a popular recreational area in Utah, USA, identifying the cause of apparent decline within a larger aspen community is complicated by development upstream and recreation-related activities. We sought to (1) assess the overall condition of the aspen at the site, (2) understand key variables that influence aspen conditions, and (3) elucidate how aspen fitness varies across the site. We collected data from forty-five plots using established aspen sampling methods, including ungulate presence, tree characteristics, soil chemistry, and environmental descriptors. Results suggest that a combination of higher levels of browsing and elevated soil sodium may be causing premature mortality and limiting aspen recruitment in a portion of the study area. These findings will inform future management at this site, as well as similar recreational forest settings experiencing compound stressors. [ABSTRACT FROM AUTHOR]

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Water pollution has become a global concern, particularly due to the escalating demand for water. This study focuses on evaluating groundwater quality for irrigation purposes in the Sidi Allal Tazi region, Morocco, utilizing the irrigation water quality index. Indices like total disolved solids, sodium percentage, Kelly's ratio, and sodium adsorption ratio suggested that 22-66% of the samples were unsuitable for irrigation, whereas primality index, magnesium ratio, and residual sodium carbonate indices classified 91-100% of the wells as appropriate for irrigation in the Sidi Allal region. The values of irrigation water quality index, about, 29% of the wells were categorized as having severe restrictions, 7% as high restrictions, 22.2% as moderate restrictions, and 42.2% as low restrictions for irrigation in study area, it indicating that more than half of the area has wells suitable for irrigation. These results suggest that the majority of wells in the Sidi Allal region is appropriate for irrigation purposes. This research further suggests implementing suitable di-chlorination, sodium reduction, and denitrification methods to enhance the quality of ground-water for irrigation use. [ABSTRACT FROM AUTHOR]

The Setifian high-plains region, Northeast of Algeria, grapples with challenges in water resource management. As the water demand intensifies across a diverse range of sectors, assessing groundwater quality becomes indispensable. This article responds to the critical need for a thorough assessment of groundwater quality in the Wadi Boussellam sub-watershed. Employing a GIS-based method, we evaluate groundwater geochemistry by estimating the Water Quality Index (WQI), offering a comprehensive overview of water consumption. The analysis of groundwater samples reveals distinct facies, including calcic bicarbonate, calcic chloride, calcic sulfate, and magnesium sulfate, contributing to an enhanced understanding of the hydrochemical composition in the Setif region. Hydrochemical indices, specifically the WQI, Sodium Adsorption Ratio (SAR), and Na% are applied to assess groundwater suitability for various applications. The results indicate that most crops are generally suitable for irrigation, though they advise exercising caution with regard to human consumption. This study underscores the significance of regular monitoring to avert groundwater contamination and ensure sustainable use in the Setif region, providing insights that emphasize the ongoing necessity for efforts in water resource management and the preservation of this vital resource's quality. [ABSTRACT FROM AUTHOR]

[Objective] To explore the optimal salt composition and salt concentration of irrigation water suitable for tomato field cultivation in arid and semi-arid areas. [Methods] Three salinity levels (1, 2, and 3 g/L) and five Na∶Ca molar concentration ratio levels (1, 3, 5, 7, and 9) of irrigation water were used in a 3-year field experiment of drip irrigation under tomato film in Yinbei irrigation district of Ningxia, China. [Results] The experiment found that with lower irrigation water salinity (1 g/L), appropriate increases in the Na∶Ca molar ratio of irrigation water were beneficial for the accumulation of tomato plant dry matter and nutrients. Tomato fruit weight, marketable yield, and total yield decreased linearly with the increase of irrigation water Na∶Ca molar ratios. Moreover, with each increase in Na∶Ca molar ratio of irrigation water, the tomato marketable yield decreased by 5 761.7 to 6 036.7 kg/hm2. Irrigation water with “high salinity (2, 3 g/L) and low Na∶Ca molar ratio (1 and 3)” was more profitable for tomato yield increase than irrigation water with “low salinity and high Na∶Ca molar ratio”. The soil sodium adsorption ratio in 0—40 cm and the amount of soil salt accumulation in 0—100 cm increased linearly with the increase of irrigation water Na∶Ca molar ratio. [Conclusion] To alleviate the soil salt accumulation and obtain a relatively high fruit yield during the growth period of field cultivated tomatoes in Yinbei irrigation area of Ningxia, irrigation water with salinity of 2 g/L and Na∶Ca molar concentration ratio of 5 was recommended for mulched drip irrigation, under the control limit of soil matrix potential at -20 kPa.

Increasing soil and underground water salinization with decreasing availability of fresh water has become a potential threat to sustainable crop production in arid and semi-arid areas globally. Introduction and evaluation of salt-tolerant halophytic crops is one of the sustainable ways to preserve productivity in saline ecosystems. This study was aimed to screen quinoa germplasms under high-sodium adsorption ratio (SAR) saline stress. Thirteen quinoa germplasms were evaluated under four levels [best available water (BAW), 8, 16, and 24 dSm−1] of high-SAR saline water irrigation. The evaluation was carried out based on growth, yield, and ionic content parameters along with statistical tools such as multivariate analysis, salt tolerance indices, and correlation. The results showed that the salinity levels of 16 and 24 dSm−1 resulted in increase of chlorophyll content relative to BAW and 8 dSm−1. The germplasm CSQ2 recorded the highest proline content (163.7 mg g−1 FW) at 24 dSm−1. Increasing levels of salinity reduced relative water content in plant leaves, and the germplasm CSQ2 showed minimal reduction of 4% at 24 dSm−1. Na+ and K+ contents in the plants increased with increasing salinity levels, while the K+/Na+ ratio decreased. The grain yield of quinoa germplasms ranged between 3.5 and 14.1 g plant−1. The germplasm EC507740 recorded the highest grain yield (7.0 g plant−1) followed by CSQ1 and CSQ2 at a maximum stress of 24 dSm−1. Principal component analysis (PCA) and correlation elucidated that Na+ content in plants was negatively correlated with all the studied traits except SPAD, proline content, and K+ content. The different salt tolerance indices indicated that the germplasms EC507740, CSQ1, CSQ2, EC507738, and IC411825 were more stable at high-SAR salinity, while PCA showed the germplasms EC507740 and CSQ2 as the most salt-tolerant germplasms. [ABSTRACT FROM AUTHOR]

This study evaluates the suitability of treated wastewater (TWW: secondary effluent and membrane effluent) for crop irrigation and the resultant impact on crop growth and soil physicochemical characteristics. Carrot seeds (Daucus carota subsp. sativus) were grown on loam soil and irrigated with tap water (Tap), secondary effluent (SE), and membrane effluent (ME) until maturity. Bacteriological analyses showed four log counts of E. coli and thermotolerant coliforms for secondary effluent, making it unsafe for the irrigation of carrots. Tap water and membrane effluent fulfilled the microbial limit for water reuse and were suitable for irrigation. The sodium absorption ratio, Kelly index, and magnesium hazard assessments indicated that all three irrigation water streams were suitable for irrigation. The average mass of carrot fruits for Tap, SE, and ME was 2.14 g, 3.96 g, and 3.03 g, respectively. A similar trend was observed for the dry matter composition: Tap had 15.9%, SE had 18.3%, and ME had 16.6%. The soil pH increased from 7.08 to 7.26, 7.39, and 7.33 for tap water-, secondary effluent-, and membrane effluent-irrigated soils, respectively. Nitrate-nitrogen and potassium levels increased in the TWW-irrigated soil, while that of the tap water-irrigated soil decreased. Sodium levels in the TWW-irrigated soil increased significantly but did not induce soil sodicity. The application of the TWW enhanced the growth of the carrot plants and increased the soil nutrient levels. Hence, using TWW in agricultural irrigation could promote food production and also limit the overdependency on freshwater resources. However, TWW should be disinfected by using UV disinfection and ozonation to reduce the risk of microbial contamination. Such disinfection methods may not lead to the formation of toxic byproducts, and therefore secondary pollution to crops is not anticipated. [ABSTRACT FROM AUTHOR]

Sodic soil formation, following irrigation with saline-sodic water has become a major concern due to its negative impact on soil structure, crop growth and yield. However, specifically in orchards, little knowledge exists regarding the reclamation of sodic soils. Our objective was to examine the effects of different amendments on soil reclamation and crop performance of olive grove. The study was conducted in a 14 years old olive grove, grown in a clayey soil, in which irrigation started in 2008 using saline-sodic water resulting in sodium adsorption ratio (SAR) ranging from 22 to 40 (mmolc L−1)0.5. Six treatments were studied: control (no amendments applied), CaCl2, MgCl2 and H2SO4 that were added to the irrigation water, and gypsiferous material (GM) that was added to the soil surface prior to the rainy season and either left spread or tilled into the upper soil layer. Soil samples were analyzed for selected saturated extract properties and for aggregate stability. Additionally, plant parameters including yield, trunk expansion, fruit oil content, and tree nutritional status were measured. The results showed that the lowest SARs were observed in the GM and GM till treatments at 0–30 cm [5.0 and 3.3 (mmolc L−1)0.5, respectively], while CaCl2 and MgCl2 treatments had the lowest SARs at 30–90 cm [16.2 and 17.1 (mmolc L−1)0.5, respectively]. GM and CaCl2 application raised the electrical conductivity (EC) levels to 6.9 and 7.6 dS m−1 respectively. GM addition resulted in the most stable aggregates which was associated with a significant improvement in average tree productivity of 33 kg/tree. Conversely, MgCl2 had the lowest average yield, of 21.3 kg/tree, which was attributed to the high concentration of Mg that led to some nutrient imbalances. In conclusion, the current study showed the efficacy of different amendments based on Ca for remediating sodic soil in drip-irrigated orchards.

Fluoride and nitrate contamination in groundwater is a global concern due to their toxicity and associated negative health effects. This study incorporated a comprehensive methodology, including hydrogeochemical analysis, drinking and irrigation water quality assessment, source apportionment, and health risk estimation of groundwater fluoride and nitrate in a lithium ore deposit basin in western Serbia. Groundwater major ion hydrogeochemistry was governed by water–rock interactions, with Ca-Mg-HCO3 identified as the predominant groundwater type. The entropy-weighted water quality index (EWQI), sodium adsorption ratio (SAR), and sodium percentage (%Na) revealed that 95% of the samples were of excellent to good quality for both drinking and irrigation. Moreover, the results showed that fluorides were of geogenic origin, whereas nitrates originated from agricultural activities. Although the fluoride and nitrate levels in groundwater were relatively low, averaging 1.0 mg/L and 11.1 mg/L, respectively, the results of the health risk assessment revealed that the ingestion of such groundwater can still lead to non-cancerous diseases. The threshold of one for the hazard index was exceeded in 15% and 35% of the samples for adults and children, respectively. Children were more vulnerable to non-carcinogenic risk, with fluorides being the primary contributing factor. The study outcomes can serve as a reference for other lithium-bearing ore areas and guide the management of regional groundwater resources.

Sodium hazard poses a critical threat to agricultural production globally and regionally which has been previously predicted from ground or surface water. Monitoring rainwater quality in this context is ignored but essential for agricultural water management in central Europe. Our study focused to predict sodium adsorption ratio (SAR) from 1985 to 2021 from ten ionic species of rainwater (pH, EC, Cl-, SO4−2, NO3-, NH4+, Na+, K+, Mg2+, Ca2+) employing four machine learning (random forest (RF), gaussian process regression (GU), random subspace (RSS), and artificial neural network-multilayer perceptron (ANN-MLP)) methods at three stations K-puszta (KP), Farkasfa (FAK), and Nyirjes (NYR) of Hungary, central Europe. Exploratory data analysis was performed using the Mann-Kendall test, Pearson correlation, and principal component analysis (PCA). Rainwater composition revealed the highest percentage of SO4−2 ions i.e., 21 to 31%, followed by 10 to 15% of Na+ ions. Mann-Kendall test revealed a significant (p

Good water quality is very vital to the productivity and sustainability of irrigated agriculture. The suitability for irrigation of groundwater samples collected and analyzed during dry and wet seasons from Ajegunle, Akufo and Eruwa farm settlements of southwestern Nigeria were assessed using several irrigation water quality indices (IWQIs). The parameters were analyzed statistically and subjected to correlation. Seasonal spatial distribution maps were generated via GIS. All the water samples from the three farm settlements were found to be mostly soft, fresh, excellent, and suitable for irrigation in both seasons. Meanwhile, soluble sodium percentage (SSP) and Kelley's Ratio (KR) revealed them as unsuitable while other parameters showed different degrees of suitability for different samples from different farm settlements in different seasons. Significant correlations were seen between the selected parameters in both seasons. The distribution maps reveal the spatial distributions of selected parameters within Ajegunle and Akufo farm settlements. Utilizing these findings will enhance systematic groundwater exploitation for irrigation within the settlements. Furthermore, systematic irrigation management practices and crop choices, based on the concentrations and distribution of the parameters viz-a-viz crop requirements should be considered to limit potential dangers that may arise with the use of the water over a long period. HIGHLIGHTS Groundwater samples were soft, fresh and of good nitrates concentrations, pH, and EC.; Irrigation parameters revealed the suitability of the water samples for irrigation.; Seasonal positive and negative significant correlations seen between selected parameters.; Spatial variation maps showed seasonal spatial distributions of selected parameters.; Enhancement of systematic groundwater exploitation for irrigation.;

The Setifian high-plains region, Northeast of Algeria, grapples with challenges in water resource management. As the water demand intensifies across a diverse range of sectors, assessing groundwater quality becomes indispensable. This article responds to the critical need for a thorough assessment of groundwater quality in the Wadi Boussellam sub-watershed. Employing a GIS-based method, we evaluate groundwater geochemistry by estimating the Water Quality Index (WQI), offering a comprehensive overview of water consumption. The analysis of groundwater samples reveals distinct facies, including calcic bicarbonate, calcic chloride, calcic sulfate, and magnesium sulfate, contributing to an enhanced understanding of the hydrochemical composition in the Setif region. Hydrochemical indices, specifically the WQI, Sodium Adsorption Ratio (SAR), and Na% are applied to assess groundwater suitability for various applications. The results indicate that most crops are generally suitable for irrigation, though they advise exercising caution with regard to human consumption. This study underscores the significance of regular monitoring to avert groundwater contamination and ensure sustainable use in the Setif region, providing insights that emphasize the ongoing necessity for efforts in water resource management and the preservation of this vital resource’s quality.

The abundance of natural fossil fuel in the Niger Delta of Nigeria has instituted generation of oilfield produced water (PW) in large volume. This constitutes environmental pollution when discharged outside the permissible limit given by Nigerian Upstream Petroleum Regulatory Commission (NUPRC). PW can be used for soil irrigation if its constituents are remediated after treatment. This research assessed the physicochemical properties of untreated and treated samples of oilfield PW from Awoba, Imo River and Kolo creek oil fields of Niger Delta using electrometric, argentometric, colorimetric, titration, atomic absorption spectroscopy, APHA and HACH standard methods. Oil-treatment facilities effectiveness was investigated by comparing laboratory results for treated-PW with the permissible regulatory values of NUPRC. The pH, salinity hazard, sodium hazard, boron, chloride, TDS, carbonate and nitrate of treated-PW were measured to check the suitability of treated-PW quality for soil irrigation. Measured values were compared with the permissible standard of US EPA. Sodium adsorption ratio (SAR) and electric conductivity (EC) were used to determine the level of sodium and salinity hazards respectively. The results indicated that none of the untreated-PW samples complied with NUPRC permissible limit. Physicochemical properties of treated-PW revealed samples to be close to or within approved NUPRC standards except in few cases. All the measured parameters of treated-PW from Awoba and Imo River oil fields conformed to the US EPA standard value except their ECs and SAR of Imo River oil field which measured 2.46 and 2.93 ds m−1, and 2.57 respectively. However, all other parameters measured for treated-PW from Kolo creek oil field did not conform to the standard except pH and nitrate which measured 7.7 and 4.86 mg/L respectively. In conclusion, oil treatment facilities should be more robust to degrade a wide range of recalcitrant compounds in PW pollutants in order to minimize the impacts of toxic compounds in PW on the environment.

This study evaluates the suitability of treated wastewater (TWW: secondary effluent and membrane effluent) for crop irrigation and the resultant impact on crop growth and soil physicochemical characteristics. Carrot seeds (Daucus carota subsp. sativus) were grown on loam soil and irrigated with tap water (Tap), secondary effluent (SE), and membrane effluent (ME) until maturity. Bacteriological analyses showed four log counts of E. coli and thermotolerant coliforms for secondary effluent, making it unsafe for the irrigation of carrots. Tap water and membrane effluent fulfilled the microbial limit for water reuse and were suitable for irrigation. The sodium absorption ratio, Kelly index, and magnesium hazard assessments indicated that all three irrigation water streams were suitable for irrigation. The average mass of carrot fruits for Tap, SE, and ME was 2.14 g, 3.96 g, and 3.03 g, respectively. A similar trend was observed for the dry matter composition: Tap had 15.9%, SE had 18.3%, and ME had 16.6%. The soil pH increased from 7.08 to 7.26, 7.39, and 7.33 for tap water-, secondary effluent-, and membrane effluent-irrigated soils, respectively. Nitrate-nitrogen and potassium levels increased in the TWW-irrigated soil, while that of the tap water-irrigated soil decreased. Sodium levels in the TWW-irrigated soil increased significantly but did not induce soil sodicity. The application of the TWW enhanced the growth of the carrot plants and increased the soil nutrient levels. Hence, using TWW in agricultural irrigation could promote food production and also limit the overdependency on freshwater resources. However, TWW should be disinfected by using UV disinfection and ozonation to reduce the risk of microbial contamination. Such disinfection methods may not lead to the formation of toxic byproducts, and therefore secondary pollution to crops is not anticipated.

Soil degradation due to salts affects over 100 countries, especially in arid and semi-arid regions where salts migrate to the plant root zone via capillary action when evapotranspiration exceeds rainfall. Soil salinity reduces germination, growth, and root development, impacting crop yields, while excess sodium decreases water movement into the soil. Soil properties, namely, electrical conductivity (ECe), sodium adsorption ratio (SARe), and pH (pHe), affected by sparingly and soluble salts, are typically analyzed using soil saturated paste (SP). However, a simpler and cost-effective alternative is assessing soil salinity using soil:water solutions at ratio 1:5 (SW). This study developed empirical models between EC1:5-ECe, SAR1:5-SARe, and pH1:5-pHe to monitor soil salinity and sodicity in Lajas Valley, Puerto Rico, an agricultural reserve with 1,140 mm of mean annual rainfall and soils classified as saline and/or sodic. The ECe Sampling, Assessment, and Prediction software for Response Surface Sampling Design (ESAP-RSSD) optimized soil sampling with 48 points. Measurements of EC, pH, cations (Ca2+, Mg2+, Na+), and SAR were conducted using SP and 1:5 SW extracts. Simple linear regression models estimated ECe (R2 > 0.93, p < 0.0001) and SARe (R2 > 0.98, p < 0.0001) from 1:5 extracts. The pHe models varied with depth, showing a strong correlation (R2 > 0.62, p < 0.0001) from 0 to 30 cm and weakening (R2 > 0.27, p < 0.0022) from 90 to 120 cm. The simple linear regression models generally perform well for EC and pH variables, with better performance observed at shallower depths. SW proves to be a practical, cost-effective, and efficient method for assessing salt-affected soils in Lajas Valley. By enabling regular soil salinity analysis, the developed estimation models combined with SW extraction could improve soil management practices and agricultural productivity.

Saline water is widely used as an alternative water resource for agriculture to overcome the freshwater shortage in arid and semiarid regions. But long-term using of the saline water for irrigation would negatively affect soil properties and crop production, and the salinity of the irrigation water should be properly managed to reduce the risks. In this study, saline water with five levels of electrical conductivities (ECiw) at 1.3 (CK), 3.4, 7.1, 10.6, and 14.1 dS·m−1 were used to irrigate winter wheat and summer maize with annual double cropping system in the North China Plain (NCP) from 2006 to 2019, to decide the threshold value for long-term using saline water. Crop yields and soil salinity were continuously examined from 2006 to 2019, and soil physicochemical properties were monitored in 2018 and 2019 after 12 years’ saline water irrigation. Results showed that soil salinity in the 0100 cm layer could be maintained at a low level using saline water with ECiw at 3.4 dS·m−1. Soil salt accumulated in winter wheat seasons could be leached from the main root zone in the following summer maize seasons, which were rainy in this region due to the monsoon climate. No significant difference was observed in grain yields for treatment with ECiw at 3.4 dS·m−1 compared to CK treatment. The electrical conductivity of the saturated soil extract (ECe), soil pH, sodium adsorption ratio, and bulk density within the top soil layer of 030 cm increased with the increase in ECiw, whereas the soil organic carbon, porosity, macroaggregates (> 0.25 mm) content, and activities of catalase, urease and alkaline phosphatase decreased, indicating the long-term using saline water irrigation deteriorated soil properties. But the difference in soil properties between the treatment of ECiw at 3.4 dS·m−1 and the CK was not apparent. There were reductions below 5% in relative grain yields and soil quality index (SQI) with ECiw lower than 3.17 and 3.10 dS·m−1 compared with CK treatment, respectively. Comprehensive consideration to maintain a stable crop production and benign soil quality, ECiw of 3.10 dS·m−1 for long-term saline water irrigation was recommended as the safe utilization threshold in the NCP.

This study aimed to assess the water quality parameters in the wastewater treatment plant (WWTP) of Ain Sefra, southwestern Algeria. Various methods were employed to analyze the performance and suitability of the WWTP for irrigation. The results revealed effective removal of nitrates, with levels below the limit set for irrigation water. The dissolved oxygen content showed efficient biological processes and good degradation of organic matter. Phosphate levels were found to be within FAO and Algerian irrigation standards. However, elevated ammonia levels were observed, exceeding typical ranges for irrigation. The suitability of groundwater for irrigation was evaluated by calculating groundwater suitability indices. These indices categorized all samples as either excellent or good based on their Sodium Adsorption Ratio (SAR) and Kelly's ratio. However, the sodium percentage values raised concerns about potential negative effects on the soil. Some samples were deemed unsuitable for irrigation because of high magnesium hazard and potential salinity values. These findings offer valuable insights into the performance and suitability of treated wastewater for irrigation in the Ain Sefra region. They can inform decision makers and stakeholders involved in agriculture and water management. [ABSTRACT FROM AUTHOR]

Groundwater salinity is a crucial factor that can impact soil structure and plant water uptake, potentially posing a threat to agricultural productivity. This study focused on assessing the salinity hazard of groundwater in low-lying coastal zones, specifically in Dar es Salaam. Thirty four boreholes were examined, and six water quality parameters (magnesium, calcium, sodium, potassium, total dissolved solids and electrical conductivity) were analyzed to investigate the feasibility of using groundwater for irrigation. Sodium adsorption ratio indices were calculated and employed to construct the Wilcox diagram, which played a crucial role in determining the groundwater suitability for irrigation. The concentrations obtained from the analysis of water quality parameters were compared to the permissible limits recommended by the Food and Agriculture Organization of the United Nations. Based on the Sodium Adsorption Ratio analysis, 14.7% of the examined samples were assigned to class one (S1), indicating irrigation-worthy water quality with minimal risk of harmful salt accumulation in the soil. On the other hand, 32.4% of the samples were categorized as class two (S2), indicating water suitable for irrigation with a significant risk that can be effectively managed. Additionally, 17.6% of the sampling points were classified as class three (S3), signifying water unsuitable for most crops. Lastly, 35.3% of the samples fell into class four (S4), suggesting water quality generally unsuitable for irrigation purposes. The analysis indicated that 94% of the samples exceeded 2250 µs/cm, classifying them as C4, indicating extremely high salinity levels rendering them unsuitable for irrigation. This study underscores the importance of conducting comprehensive research before utilizing groundwater for irrigation in low-lying coastal zones.

The current study was carried out to evaluate the effect of rice straw biochar amendment and to identify the appropriate dose of biochar application to reduce soil acidity, salinity, toxicity, and sodicity in salt-affected acid soils. The rice straw biochar at 4 different rates of 0%, (control) 1%, 3%, and 5% (w/w) was mixed with 6 salt-affected acid soils: S1 (non-saline), S2 and S3 (low saline), and S4, S5, and S6 (moderate saline). The mixture was continuously shaken in distilled water for 7 days. The biochar application significantly increased soil pH and saturated electrical conductivity (ECe) with an increasing biochar application rate compared with the control. Significant decreases in sodium adsorption ratio (SAR) and exchangeable sodium percentage (ESP) values below the critical level of sodicity were observed above the biochar application rate of 1%. Soluble chloride (Cl ^– ) and soluble and exchangeable sodium (Na ^+ ) were significantly reduced above the biochar application rate of 1%. The biochar application (≥ 1%) led to a significant increase in soluble and exchangeable potassium (K ^+ ) and declines in soluble and exchangeable calcium (Ca ^2+ ) and magnesium (Mg ^2+ ). This study concluded that the biochar application rate of 1% was suitable for reducing soil acidity to a safe level for rice plants. The rice straw biochar application improved soil toxicity and sodicity by reducing soluble Cl ^– and soluble and exchangeable Na ^+ , decreasing SAR and ESP. The biochar application also increased available K ^+ , essential for rice plant growth and development in salt-affected soils.

Deficit irrigation practices carried out in very high-density olive orchards grown in the Alentejo region of southern Portugal can bring important economic benefits in terms of water savings, yields, and oils. They can also result in serious salinization/sodification problems without proper management of soil and water resources. The main objective of this study was to evaluate the long-term (30 years) impact of those irrigation practices on local soil resources using a multicomponent transport modeling approach embedded in the HYDRUS-1D model. Soil salinization and sodification risks were quantified for 160 soil profiles by considering eight different scenarios: current monitored irrigation practices (S1), using waters of variable quality (S2-S6), planting maize as an alternative crop (S7), and using climate change projections for the region (S8). Despite the large observed variability, simulations that considered current irrigation practices (S1) produced average values of the electrical conductivity of the soil solution (EC sw ) at the end of the leaching seasons always below the threshold limit for crops moderately tolerant to soil salinity. In this scenario, the average values of the sodium adsorption ratio (SAR) were also kept within the same magnitude of those determined at the beginning of the simulation period (initial conditions). Irrigations with worse quality waters (S2-S6) led to higher EC sw and SAR values. Although annual rainfall amounts influenced the salinity build-up, the SAR evolution depended mainly on water quality. In maize soil profiles (S7), the simulated EC sw and SAR values were lower than in olive soil profiles, with irrigation practices contributing to salt removal during the seasons. Conversely, the climate change scenario (S8) resulted in slightly higher EC sw and SAR values than those simulated for current conditions, indicating a potentially greater risk of soil degradation in the near future. Although current irrigation practices seem to present relatively low soil salinization/sodification risks, the variability of results and the uncertainty associated with model predictions indicate that close monitoring to prevent further degradation of soil and water resources in the region should be recommended.

Deficit irrigation practices carried out in very high-density olive orchards grown in the Alentejo region of southern Portugal can bring important economic benefits in terms of water savings, yields, and oils. They can also result in serious salinization/sodification problems without proper management of soil and water resources. The main objective of this study was to evaluate the long-term (30 years) impact of those irrigation practices on local soil resources using a multicomponent transport modeling approach embedded in the HYDRUS-1D model. Soil salinization and sodification risks were quantified for 160 soil profiles by considering eight different scenarios: current monitored irrigation practices (S1), using waters of variable quality (S2-S6), planting maize as an alternative crop (S7), and using climate change projections for the region (S8). Despite the large observed variability, simulations that considered current irrigation practices (S1) produced average values of the electrical conductivity of the soil solution (EC sw ) at the end of the leaching seasons always below the threshold limit for crops moderately tolerant to soil salinity. In this scenario, the average values of the sodium adsorption ratio (SAR) were also kept within the same magnitude of those determined at the beginning of the simulation period (initial conditions). Irrigations with worse quality waters (S2-S6) led to higher EC sw and SAR values. Although annual rainfall amounts influenced the salinity build-up, the SAR evolution depended mainly on water quality. In maize soil profiles (S7), the simulated EC sw and SAR values were lower than in olive soil profiles, with irrigation practices contributing to salt removal during the seasons. Conversely, the climate change scenario (S8) resulted in slightly higher EC sw and SAR values than those simulated for current conditions, indicating a potentially greater risk of soil degradation in the near future. Although current irrigation practices seem to present relatively low soil salinization/sodification risks, the variability of results and the uncertainty associated with model predictions indicate that close monitoring to prevent further degradation of soil and water resources in the region should be recommended.

This study identifies the major geochemical processes that regulate groundwater quality in the Hombolo catchment to make it suitable for drinking and irrigation purposes. The major cations and anion concentrations were used to develop the major geochemical processes governing the groundwater quality. The major geochemical processes were evaluated using historical data gathered from 1983 to 2018. The developed geochemical processes indicated the mineral dissolution, ion exchange and evaporation were the dominant that influence groundwater quality in the catchment using mole ratio concept and Gibbs diagram. The suitability of groundwater for irrigation was evaluated using the permeability index (PI), sodium adsorption ratio (SAR), and percentage soluble sodium (PSS) while the suitability of groundwater for drinking was evaluated using the water quality index (WQI). The sodicity indicated to have the average SAR of 5.16 as excellent class, average PSS of 50.89 as permissible to good class and average PI of 74.47 as suitable class level. The groundwater for drinking use indicated the WQI of 104 as poor class level. The groundwater is suitable for irrigation activities but the quality for drinking is deteriorating with time. HIGHLIGHTS The geochemical processes governing groundwater chemistry are explained.; In turn, it raises the community's attention about the groundwater quality problems and pushes them to avoid practices that contribute to the deterioration of groundwater quality near the groundwater resources.; It assists policymakers and management personnel in better utilizing the gathered pieces of information for better groundwater management.;

Water plays a vital role in different physiological functions like maintenance of turgidity, nutrient uptake and metabolic processes in plants. The application of groundwater has been adopted for crop cultivation in many water-scarce areas. However, the quality of groundwater is deteriorating day by day due to urbanization and industrialization. Therefore, a five-year (2015-2020) study was conducted to assess the fitness of groundwater being used for field application in different tehsils of Rawalpindi District. A total of 559 samples were collected in six tehsils of Rawalpindi, analyzed and categorized according to suitability criteria set by FAO (2013). Mean data showed that 70% of the total samples were fit, 9% marginally fit and 21% were found unfit for irrigation purposes. It was also recorded that a maximum (37%) of total unfit samples belonged to Gujar Khan tehsil whereas, the majority of samples of Taxila tehsil were fit compared to other Tehsils of Rawalpindi District. About 14.7% of water samples were recorded unfit due to Electrical Conductivity (EC), 5.9% due to Sodium Adsorption Ratio (SAR), 11.4% due to Residual Sodium Carbonate (RSC), 19.4% due to EC+RSC, 14% due to EC+SAR, 8% due to SAR+RSC, and 11.8% were unfit in terms of EC+RSC+SAR. Depending upon water quality, farmers were advised to use good quality water for crops. Suitable remedial measures for marginally fit/unfit water samples were suggested considering the salinity or sodicity of the samples. [ABSTRACT FROM AUTHOR]

Groundwater is one of the main sources of water for irrigation used worldwide. However, the application of the resource is threatened by the possibility of high saline levels, especially in low-lying coastal regions. Furthermore, the lack of readily accessible materials for successful treatment procedures makes the purification of such water a constant challenge. Based on the fact that natural zeolite is one of the easily accessible and relatively cheap filter materials, this study examined the potential use of high-salinity groundwater filtered by natural zeolite for irrigation. Zeolite-filled filters at two different depths (0.5 m and 1 m) were studied. The samples were collected from the low-lying areas of Dar es Salaam City, Tanzania. The study observed that when the raw groundwater samples were exposed to the 0.5 m column depth, sodium (Na+) had the lowest removal efficiency at 40.2% and calcium (Ca2+) had the highest removal efficiency at 98.9%. On the other hand, magnesium (Mg2+) had the lowest removal efficiency, at about 61.2%, whereas potassium (K+) had up to about 99.7% removal efficiency from the 1 m column depth treatment system. Additionally, from the salinity hazard potential analysis, most of the samples fell within C4 (based on the electrical conductivity), which is a "very high salinity" class, and based on the quality it means the water cannot be directly applied for irrigation purposes. From the 0.5 m column depth, most of the samples fell within C3 (the "high salinity" class), and from the 1 m column depth most of the samples fell within C1 ("low salinity" class). The findings of this study offer some valuable insight into the prospective use of natural zeolite for the filtration of saline groundwater before its application for irrigation. [ABSTRACT FROM AUTHOR]

The research was implemented to monitor the effects of sea level rise on some soil properties associated with salt affected soils in agricultural areas on the Lower Central Plain, Thailand and determine the severity of salt impact during different periods in these areas. To achieve these goals, soil samples from 11 locations were selected for investigation. All soils were deep, poorly drained, mainly fine textured, and low developed. The soil moisture ranged from 20.84-79.04%. Soil electrical conductivity (ECe) varied substantially between locations, depth levels, and periods of soil sampling, ranging from 0.21-4.42 dS/m. The sodium adsorption ratio (SAR) of these soils during the periods of soil sampling was rather higher than 13 in either some or all layers of the soil profiles, ranging from 6.80-41.89. These results suggested that many of the study locations were affected by salts and all sites could be classified as sodic soils with the classification increasing to saline-sodic soils in locations N4 in April, N5 in March, July and August, and P4 in March 2018. Thus, during these occasions, it was possible that the increased salt levels were due to the rising sea level compared to during May and June when there was high precipitation.

The use of saline water resources in agriculture is becoming a common practice in semi-arid and arid regions such as the Mediterranean. In the SmaCuMed project, the desalination of brackish groundwater (TDS = 2.8 g/L) for the irrigation of Argan trees in Essaouira, Morocco, to 2 g/L and 1 g/L (33% and 66% salt removal, respectively) using low-pressure reverse osmosis (LPRO) (p < 6 bar) and membrane capacitive deionization (MCDI) was tested at pilot scale. MCDI showed 40–70% lower specific energy consumption (SEC) and 10–20% higher water recovery; however, the throughput of LPRO (2.9 m3/h) was up to 1.5 times higher than that of MCDI. In addition, both technologies were successfully powered by PV solar energy with total water costs ranging from EUR 0.82 to EUR 1.34 per m3. In addition, the water quality in terms of sodium adsorption ratio was slightly higher with LPRO resulting in higher concentrations of Ca2+ and Mg2+, due to blending with feed water. In order to evaluate both technologies, additional criteria such as investment and specific water costs, operability and brine disposal have to be considered.

Groundwater in the Touggourt region—or as its named, Oued Righ—in southeastern Algeria, is the only source of irrigation. To assess its suitability for agricultural purposes, we collected 72 samples from wells at this region, physical and chemical measurements were carried out for each water sample, and calculations of the sodium adsorption ratio (SAR), permeability index (PI), soluble sodium percent (SSP), residual sodium carbonate (RSC), magnesium hazard ratio (MHR) and Kelley's ratio (KR) were carried out, as these indices are often used to assess the suitability of groundwater for irrigation uses. Based on the irrigation water quality index (IWQI) values, a spatial distribution map for each parameter using the inverse interpolation technique (IDW) was produced by Geographical Information System (GIS). According to the IWQI map, about 35% of the water samples analyzed fall into the Severe Restriction category (SR), making it unsuitable for irrigation under normal circumstance. Again, the remaining 65% of the groundwater has a high restriction (HR) for use. Groundwater in the study area could be used for irrigation in highly permeable soils where salt-tolerant crops are grown. Adequate drainage and continuous monitoring of water quality are recommended. [ABSTRACT FROM AUTHOR]

The processes of sodication and desodication in soil influences agricultural productivity. We explored sodication and desodication processes in montmorillonite and illite with varying ratios of clay contents in 5% and 25 % on sodium adsorption ratios (SAR) of 7, 13, and 20 of equilibrated solution with 10 mmolc L-1. The sodication and desodication processes were observed to vary considerably, depending on the type of clay, clay content, and equilibrated solution. Sodication and desodication processes were different even for the same clay under similar conditions. The differences in clay sodication based on SAR of equilibrated solution were observed, and it was found that sodication progressed comparatively more rapid in illite than in montmorillonite. The desodication processes varied according to the type of clay and clay content. In montmorillonite, desodication progressed comparatively better at low clay content than at high clay content. In contrast, it progressed more rapid at high clay content than at low clay content in illite. However, desodication processes in illite with low clay content had similar tendencies as SAR of an equilibrated solution. As a result, the Gapon equilibrium constant was different for clay sodication and desodication processes even in the same clay mineral and clay content. The clay sodication and desodication processes as well as final exchangeable sodium percentage values were affected not only by SAR of the equilibrated solution but by the type of clay minerals and clay contents as well. [ABSTRACT FROM AUTHOR]

Sodic soil formation, following irrigation with saline-sodic water has become a major concern due to its negative impact on soil structure, crop growth and yield. However, specifically in orchards, little knowledge exists regarding the reclamation of sodic soils. Our objective was to examine the effects of different amendments on soil reclamation and crop performance of olive grove. The study was conducted in a 14 years old olive grove, grown in a clayey soil, in which irrigation started in 2008 using saline-sodic water resulting in sodium adsorption ratio (SAR) ranging from 22 to 40 (mmol c L−1)0.5. Six treatments were studied: control (no amendments applied), CaCl 2 , MgCl 2 and H 2 SO 4 that were added to the irrigation water, and gypsiferous material (GM) that was added to the soil surface prior to the rainy season and either left spread or tilled into the upper soil layer. Soil samples were analyzed for selected saturated extract properties and for aggregate stability. Additionally, plant parameters including yield, trunk expansion, fruit oil content, and tree nutritional status were measured. The results showed that the lowest SARs were observed in the GM and GM till treatments at 0–30 cm [5.0 and 3.3 (mmol c L−1)0.5, respectively], while CaCl 2 and MgCl 2 treatments had the lowest SARs at 30–90 cm [16.2 and 17.1 (mmol c L−1)0.5, respectively]. GM and CaCl 2 application raised the electrical conductivity (EC) levels to 6.9 and 7.6 dS m−1 respectively. GM addition resulted in the most stable aggregates which was associated with a significant improvement in average tree productivity of 33 kg/tree. Conversely, MgCl 2 had the lowest average yield, of 21.3 kg/tree, which was attributed to the high concentration of Mg that led to some nutrient imbalances. In conclusion, the current study showed the efficacy of different amendments based on Ca for remediating sodic soil in drip-irrigated orchards. • Soils irrigated with sodic water require reclamation. • Gypsiferous material addition yielded stable aggregates and improved crop productivity. • Adding CaCl 2 and MgCl 2 effectively decreased SAR to a depth of 90 cm. • Amending with MgCl 2 caused nutrient imbalances. • Addition of sulferic acid was ineffective in sodic soil remediation. [ABSTRACT FROM AUTHOR]

Subsurface pipe drainage technology can effectively improve coastal saline land in Northern China. We explored an okra (Abelmoschus esculentus L.)-assisted subsurface pipe drainage system to improve the water and salt discharge performance and benefits. In this study, the simulation box experiment was conducted to research the response of water and salt discharge performance in subsurface pipe drainage to okra root weight density (RWD). The drain outflow, soil salinity, and sodium adsorption ratio were determined. The results showed that okra RWD affected the vertical distribution of okra roots. Okra with an appropriate RWD (about 116 μg·cm−3) could significantly increase the cumulative drain outflow. Okra with an appropriate RWD (about 136 μg·cm−3) could significantly increase the desalting effect. Moreover, the RWD of okra also influenced the ability of subsurface pipe drainage to inhibit soil alkalization. The above results show that planting okra and installing subsurface pipe drainage to control drainage at the coastal saline land in Northern China can effectively improve the water and salt drainage effect when okra RWD is about 116–136 μg·cm−3. When using subsurface pipe drainage to improve coastal saline soils, planting okra with proper density may be an appropriate choice to improve the effect and benefit. [ABSTRACT FROM AUTHOR]

Continuous use of recycled water (treated wastewater) over a long period of time may lead to the accumulation of salt in the root zone of the soil. This is due to the relatively higher levels of salt contained in the recycled water compared to a town water supply. The increase in salt concentration in the soil can adversely influence the amount of water a plant can uptake from the soil due to the osmotic effect. Despite significant benefits, recycled water may deteriorate soil health in terms of increased salinity and sodicity. Although several studies in the past have highlighted the increase of soil salinity due to recycled water irrigation, the phenomenon depends on the variability of soil characteristics. In this study, the impact of using three different types of irrigation water (with electrical conductivity 0.2, 0.8, and 2.0 dS/m) on the mechanism of salt accumulation in the soil was investigated. To contribute to the addition of the existing knowledge of soil salinisation, soil from two paddocks (i.e., D33 and Yarramundi) in Western Sydney, Australia were analysed, and relationships among parameters associated with salt accumulation were evaluated using the results from continuous column studies. Results show that if the irrigation is conducted with high saline water, there is a possibility for salinisation of soil to occur. To prevent this from occurring, one of the solutions could be to use a normal town water supply for irrigation at some intervals. This will allow for the leaching of excess salt accumulated in the soil to deeper layers. [ABSTRACT FROM AUTHOR]

In order to study the effect of phosphogypsum and humic acids in the kinetic release of salt from salt affected soil, a laboratory experiment was conducted in which columns made from solid polyethylene were 60.0 cm high and 7.1 cm in diameter. The columns were filled with soil so that the depth of the soil was 30 cm inside the column, the experiment included two factors, the first factor was phosphogypsum and was added at levels 0, 5, 10 and 15 tons ha-1 and the second factor humic acids were added at levels 0, 50, 100 and 150 kg ha-1 by mixing them with the first 5 cm of column soil and one repeater per treatment. The continuous leaching method was used by using an electrolytic well water 2.72 dS m-1. Collect the leachate daily and continue the leaching process until the arrival of the electrical conductivity of the filtration of leaching up to 3-5 dS m-1. The electrical conductivity and the concentration of positive dissolved ions (Ca, Mg, Na) were estimated in leachate and the sodium adsorption ratio (SAR) was calculated. The results showed that the best equation for describing release kinetics of the salts and sodium adsorption ratio in soil over time is the diffusion equation. Increasing the level of addition of phosphogypsum and humic acids increased the constant release velocity (K) of salts and the sodium adsorption ratio. The interaction between phosphogypsum and humic acids was also affected by the constant release velocity of salts and the sodium adsorption ratio. The constant release velocity (K) of the salts and the sodium adsorption ratio at any level of addition of phosphogypsum increased with the addition of humic acids. The highest salts release rate was 216.57 in PG3HA3, while the lowest rate was 149.48 in PG0HA0. The highest release rate of sodium adsorption ratio was 206.09 in PG3HA3, while the lowest rate was 117.23 in PG0HA0.

Groundwater is one of the main sources of water for irrigation used worldwide. However, the application of the resource is threatened by the possibility of high saline levels, especially in low-lying coastal regions. Furthermore, the lack of readily accessible materials for successful treatment procedures makes the purification of such water a constant challenge. Based on the fact that natural zeolite is one of the easily accessible and relatively cheap filter materials, this study examined the potential use of high-salinity groundwater filtered by natural zeolite for irrigation. Zeolite-filled filters at two different depths (0.5 m and 1 m) were studied. The samples were collected from the low-lying areas of Dar es Salaam City, Tanzania. The study observed that when the raw groundwater samples were exposed to the 0.5 m column depth, sodium (Na+) had the lowest removal efficiency at 40.2% and calcium (Ca2+) had the highest removal efficiency at 98.9%. On the other hand, magnesium (Mg2+) had the lowest removal efficiency, at about 61.2%, whereas potassium (K+) had up to about 99.7% removal efficiency from the 1 m column depth treatment system. Additionally, from the salinity hazard potential analysis, most of the samples fell within C4 (based on the electrical conductivity), which is a “very high salinity” class, and based on the quality it means the water cannot be directly applied for irrigation purposes. From the 0.5 m column depth, most of the samples fell within C3 (the “high salinity” class), and from the 1 m column depth most of the samples fell within C1 (“low salinity” class). The findings of this study offer some valuable insight into the prospective use of natural zeolite for the filtration of saline groundwater before its application for irrigation.

The research was implemented to monitor the effects of sea level rise on some soil properties associated with salt affected soils in agricultural areas on the Lower Central Plain, Thailand and determine the severity of salt impact during different periods in these areas. To achieve these goals, soil samples from 11 locations were selected for investigation. All soils were deep, poorly drained, mainly fine textured, and low developed. The soil moisture ranged from 20.84-79.04%. Soil electrical conductivity (ECe) varied substantially between locations, depth levels, and periods of soil sampling, ranging from 0.21-4.42 dS/m. The sodium adsorption ratio (SAR) of these soils during the periods of soil sampling was rather higher than 13 in either some or all layers of the soil profiles, ranging from 6.80-41.89. These results suggested that many of the study locations were affected by salts and all sites could be classified as sodic soils with the classification increasing to saline-sodic soils in locations N4 in April, N5 in March, July and August, and P4 in March 2018. Thus, during these occasions, it was possible that the increased salt levels were due to the rising sea level compared to during May and June when there was high precipitation. [ABSTRACT FROM AUTHOR]

This study attempts to find a fuzzy logic system for assessing the quality of water in water treatment plants (WTPs) providing water for irrigation purposes in the Basrah Governorate (South of Iraq). Each month, samples are taken in each of six major WTPs to measure electrical conductivity (EC), and the content of sodium, magnesium and calcium. The calculated value which is the sodium adsorption ratio (SAR) is plotted with EC on the Richard diagram. SAR and EC values are combined together in a fuzzy inference system (FIS) to find out a quality number called the fuzzy irrigation water quality index number (FIWQI) which ranges from zero to one. The higher the value of the index, the better water quality. The Richard diagram, which helps to classify irrigation water, is used to adjust FIS components. Results show that the FIWQI for all WTPs changes depending on location and season. It ranges between 0.114–0.170, 0.120–0.190, 0.114–0.170, 0.114–0.202, 0.118–0.500 and 0.46–0.500 for Al-Bradhaia 1, Al-Jubaila 1, Shatt Al-Arab, Garmmah 1, Al-Rebat, and Old Shauaibah WTPs, respectively. The results indicate that WTPs effluent drawn from the Shatt Al-Arab River has poor water quality for irrigation purposes, except for an Old Shauaibah which receives water from another source called a sweet water canal. FIS results are compared with values obtained from the Richard diagram and 96% degree of compatibility between the two methods is attained. This indicates that FIS is an acceptable method for water quality classification. [ABSTRACT FROM AUTHOR]

Exploration was conducted in the study area of Coimbatore district by collecting 60 samples from the agricultural belt. The groundwater is neutral to alkaline in character with pH varying from 6.70 to 9.02 among the mean of 7.37. Elevated electrical conductivity (EC) was observed in upstream parts of the study area. Water quality for irrigation is determined by several key components like electrical conductivity (EC), total suspended solids (TDS), residual sodium carbonate (RSC), chloro alkali Indices (CA I & CAII), sodium adsorption ratio (SAR), percent sodium (%Na), Kelley’s ratio (KR), magnesium hazard (MH), permeability index (PI) and soluble sodium percent (SSP). In total, six samples were found to be with high salinity hazard. The mean value of SAR was found to be 5.24, maximum sample falls under C2S1 to C4S1 category as per USSL Salinity diagram. As per Piper diagram in the anionic regime, Cl dominates HCO3-, CO3- and SO42- Higher magnesium hazard in the groundwater is owing to the consequence of dyeing and bleaching industries. Magnesium hazard value indicates that 51 samples out of 60 are unsuitable for irrigation. According to the study, it is revealed that groundwater in the study area is contaminated by both natural factors and anthropogenic activities. [ABSTRACT FROM AUTHOR]

Sodium hazard poses a critical threat to agricultural production globally and regionally which has been previously predicted from ground or surface water. Monitoring rainwater quality in this context is ignored but essential for agricultural water management in central Europe. Our study focused to predict sodium adsorption ratio (SAR) from 1985 to 2021 from ten ionic species of rainwater (pH, EC, Cl-, SO 4 −2, NO 3 -, NH 4 +, Na+, K+, Mg2+, Ca2+) employing four machine learning (random forest (RF), gaussian process regression (GU), random subspace (RSS), and artificial neural network-multilayer perceptron (ANN-MLP)) methods at three stations K-puszta (KP), Farkasfa (FAK), and Nyirjes (NYR) of Hungary, central Europe. Exploratory data analysis was performed using the Mann-Kendall test, Pearson correlation, and principal component analysis (PCA). Rainwater composition revealed the highest percentage of SO 4 −2 ions i.e., 21 to 31%, followed by 10 to 15% of Na+ ions. Mann-Kendall test revealed a significant (p < 0.05) increasing trend of Na+ ions and SAR portraying it a serious hazard limiting agricultural production. Machine learning results from 10 model runs of all algorithms for SAR prediction at KP station proved the efficacy of ANN-MLP as superior with RMSE range of 0.02 to 0.05, followed by RF with RMSE of 0.14 to 0.19 in scenario 2 (SC-2) (Na+, Mg2+, Ca2+). Validation of the best-selected algorithm (ANN-MLP) and scenario (SC-2) also predicted the SAR with a low RMSE of 0.08 and 0.05 at both FAK and NYR stations, respectively. Hence, the efficiency of ANN-MLP in forecasting SAR from rainwater proves it to be a meticulous tool for enhancing agricultural water management practices in Central Europe and enhancing resource efficiency and crop production in the future. • Rainwater of central Europe is characterized by high concentrations of sulphate (SO 4 −2), and sodium (Na+) ions. • Sodium adsorption ratio is found to have significant (p < 0.001) negative correlation with all ions except sodium. • Artificial neural network-multilayer perceptron performed superior for predicting SAR among four ML algorithms. • Scenario 2 (Na+, Mg2+, Ca2+) provided more accurate SAR predictions compared to scenario 1. [ABSTRACT FROM AUTHOR]

[Display omitted] The sodium adsorption ratio (SAR) is the most crucial irrigation water quality indicator to diagnose the suitability of agricultural water resources. Due to this reason, accurate forecasting of SAR in the absence of its time series, based on limited input sequences, is recently considered a challenging environmental issue on a monthly scale. This research developed a dual eXplainable multivariate expert framework for the first time to forecast monthly SAR at Zayanderud River, Iran. The framework (i.e., BS-GPR-E.TVF-EMD-VMD) consisting of a Boruta coupled with SHapley Additive exPlanations (Boruta-SHAP) feature selection, an ensemble of time-varying filter-based empirical mode decomposition (TVF-EMD) and variational modal decomposition (VMD), namely (E.TVF-EMD-VMD), and eXplainable Gaussian process regression (GPR). The main novelty of this framework is converting the "black-box" nature of the forecasting model to a dual interpretable "glass box" before and during the learning process. For this purpose, among nine hydrometric and water quality parameters associated with Zayanderud River at two stations (Regulating dam and Zaman Khan) over the period of 1969 to 2016, the significant two-month antecedent information (lags) signals were extracted using the Boruta-SHAP feature selection. Afterwards, the optimal inputs signal lags for each station were decomposed into sub-components to reduce the complexity and non-stationary of original signals using three pre-processing techniques (i.e., E.TVF-EMD-VMD, TVF-EMD, and VMD). The decomposed predictors were employed as inputs into the multilayer perceptron neural network (MLP), Random Forest (RF), Elman recurrent neural network (ERNN), and eXplainable GPR approaches. Statistical validation and infographic tools revealed that the BS-G PR -E.T VF-EMD -V MD regarding the best performance in the Regulating dam (R = 0.9817, RMSE = 0.1431, and NSE = 0.8866) and Zaman Khan (R = 0.9632, RMSE = 0.0610, and NSE = 0.9233) stations, outperformed the other complementary and standalone counterpart frameworks followed by the BS-G PR -T VF-EMD and BS-E RNN -E.T VF-EMD -V MD , respectively. SHAP explainer through the GPR model clearly interpreted the effect of the lagged-time sub-components related to each predictor and represented the impact of each decomposition technique on the input signals through E.TVF-EMD-VMD aiming to forecast SAR in standalone and complementary frameworks. [ABSTRACT FROM AUTHOR]

Abstract Groundwater under Basement Complex areas of southern Kebbi has been characterized in order to determine its suitability for drinking and irrigation use. Water samples were drawn from shallow groundwater (hand-dug shallow wells 40 m). Physical parameters (i.e., temperature, TDS, pH, and EC), were determined in situ, using handheld meters. Discrete water samples were obtained for determination of chemical parameters. Results from several-sample ANOVA (Kruskal–Wallis test) suggested that heterogeneity in water table appeared to exert significant influence on groundwater chemistry which is characterized by a significant difference in pH, EC TH, Na+, Zn2+, Mg2+, PO4 3−, Cl−, HCO3 −, SO4 2−, and NO3 − concentrations. Also, ions including Fe3+, Zn2+, Mg2+, Na+, PO4 3−, and SO4 2− are above World Health Organization (2011) and National Standard for Drinking Water Quality (2007) reference guidelines. Most of the groundwater sources are moderately hard. Groundwater classification based on chloride, EC, and TDS revealed water of excellent quality for all types of uses. However, groundwater classification based on nitrate pollution revealed water of poor quality. Rock mineral is the major mechanism controlling water chemistry, as revealed by the Gibbs model. Most of the water sources have positive Scholler index, indicative of overall base exchange reactions in the underlying aquifers. Such condition was well explained by Piper trilinear diagram, which revealed two types of faces: Ca–Mg–HCO3 and Ca–Mg–SO4–Cl. The HCA categorized wells into three groups according to their hydrogeochemical physiognomies. Despite the significant difference in ions concentration and chemical indices, groundwater composition is more influenced by rock weathering than anthropogenic inputs. Groundwater evaluation for irrigation use indicates a significant difference in SAR level which is related to poor permeability index in shallow groundwater. Higher values of Kelly’s index and magnesium adsorption ratio threatened groundwater suitability for irrigation use in the study area.

Abstract Mahananda River is an important river in India and Bangladesh, as the people of both the countries use the water extensively, without sufficient and reliable information about water qualities and pollution status. The purpose of this study is to evaluate the water quality of the river and to analyse the suitability for drinking, agricultural and industrial uses. This is why this study on the Mahananda River is extremely important for the region. For this study, samples from fourteen sampling stations were collected in pre-monsoon and post-monsoon seasons in 2016 and water quality index (WQI), agriculture and industry-related indices were computed. WQI values designated two sampling stations out of fourteen sampling stations as ‘very bad’ category and another two sampling stations as ‘bad’ category. The pH values of some sampling stations slightly exceeded the upper permissible limit. USSL diagram analysis classified two samples of pre-monsoon season in C2S1 category which indicates a medium salinity and low sodium water. Magnesium hazard values of four sampling stations are above 50% suggesting not suitable for irrigation. However, some indices like sodium per cent, residual sodium carbonate and residual sodium bicarbonate, Kelly’s index, permeability index and potential salinity allow the water for use in irrigation purposes. Langelier Saturation Index and aggressive index values designate the water as moderately aggressive or non-aggressive. Ryznar Stability Index values designate the water as ‘aggressive’ or ‘very aggressive’ indicating unsuitability for industrial uses. Sampling stations S-1, S-2, S-8 and S-14 need special attention.

The influence of water resources allocation patterns on root layers soil desalination and groundwater quality were investigated by monitoring different irrigation area from People’s Victory Canal irrigation district in Huang Huai Hai plain China that had been conducted well canal combined irrigation patterns from 1954. A typical area was chosen belong to the People’s Victory Canal irrigation district from 2013 to 2015. Precipitation of the area, surface water irrigation amount, groundwater consumption amount, salinity content in 0 to 100 cm soil layer and total dissolved solids in groundwater were monitored, the ratio of canal-well water (the ratio of surface water to groundwater irrigation amount, CWWR), soil salinity spatial dynamic, desalinization rate in 0 to 100 cm soil layer and sodium adsorption ratio (SAR) of groundwater were analyzed in the area. CWWR of 1st, 2nd, 3rd branch canals ranged from 0.72 to 1.03, 2.50 to 2.63, and 0.65 to 1.26 in 2013 to 2015, respectively. The soil salinity contents for the top 100 cm horizons in the 2nd branch canal irrigation area decreased slightly by 1.63% to 8.90% compared with the values in the 1st and 3rd branch canal irrigation districts while the water resources allocation patterns were conducted two years later. Compared with the area in the hydrological period in 2013, area of average soil salinity exceeded 0.32 mS/cm for the top 20 cm horizons has decreased notably in 2014 and 2015. Compared with the values in 2014, the average TDS concentration of groundwater increased by 18.66% in the study area in 2015, while the sodium adsorption ratio (SAR) values in the above-mentioned irrigation areas decreased by 23.58%, 36.82%, and 53.37% in the normal period in 2015. The combined well-canal irrigation pattern could represent a useful water allocation method mainly because of the temporal and spatial regulation of water resources and root layer soil desalination; however, possible increases of TDS in the groundwater may cause potential ecosystem degradation risks after long-term water allocation in semi-arid areas. Thus, water allocation should be emphasized to maintain a healthy groundwater environment and sustainable stable yields of grain in combined canal-well irrigation districts

The study was conducted to determine the relationship between the exchangeable sodium percentage ESP and sodium adsorption ratio SAR in the soil solution. Some saline affected soils were selected at the locations Yosifya, Muwayliha, Imam, Eychreesh, Mahaweel, Ejbalah, Abe-Ghragg, Kifil, Elseneya and Eldagharaah. Using thermodynamic criteria to recalculate throught description quantitative concepts rather than analytical.The results indicate that the values of SAR range from 0.96 - 26.80 (cmol Kg-¹)º•5 of the studied sites and this ratio increased when taking into account free ions 3.52 - 32.7 (cmol Kg-¹)º•5. The ESP Calculated laboratory was (2.0 - 9.0 %) and all of these were less than ESP % according to laboratory salinity accounts, and generally show increase in the values of the proportion of ESP with increased SAR according to the approved indicators. The probability of these soils turning into sodic is unlikely to decrease pH and HCO3-¹ values and increase concentrations of calcium and magnesium ions. The statistical results indicated that in order to predict soil ESP based on soil SAR the linear regression model for predicting soil ESP from SAR. ESP=1.95+1.05SAR with R²=0.92 can be recommended. R² = 0.92.

Abstract The grade of irrigation water available to irrigators has a significant impact on crops as well as yields. Therefore, it is a need to better understand irrigation water quality. The present study mainly focuses on the assessment of the suitability of water of forty-four fixed bore wells of Kanchipuram district, Tamil Nadu, India. The groundwater sample datasets of post-monsoon (2005–2013) and pre-monsoon (2006–2013) season were collected for 9 years. Water quality indices, namely sodium adsorption ratio, exchangeable sodium percent (SSP or %Na), residual sodium carbonate (RSC or RA), Kelly’s ratio, permeability index, chloroalkaline indices (CAI1 and CAI2), potential salinity (PS), magnesium hazard, total dissolved solids and total hardness, have been calculated for separate bore wells. The r 1 and r 2 indices show that groundwater of the study area is Na+–SO4 2− and deep meteoric percolation type. Majority of the wells are fall under moderate to unsuitable category of water for irrigation purposes. Further, wells water has also been classified on the base of meteoric genesis index.