Fresh Saline Research Articles

Can molecular oscillation technology be used as an alternative to acid injection to prevent the clogging of emitters in drip irrigation systems?

AbstractIn this study, molecular oscillation technology (Merus ring), developed to prevent calcification, biofilm formation and corrosion in piping in industrial water treatment systems, was compared as an alternative to acid injection to prevent the clogging of emitters by chemicals, and fresh and saline water were compared on the basis of system performance parameters (coefficient of variation, distribution uniformity, Christiansen uniformity, emission uniformity) and economic aspects. The results revealed that both acid injection and the Merus ring in saline and fresh water resulted in significantly higher average emitter flow rates than the control treatment. Both the Merus ring and the acid injection achieved higher performance parameters with fresh water than with saline water. Acid injection was found to be more effective in preventing clogging of the emitters than the Merus ring when saline water was used. Compared with fresh water, saline water increases emitter clogging. The economic analysis revealed that the Merus ring was more economical ($204.3 ha−1) than acid injection with both fresh water ($318.2 ha−1) and saline water ($578.6 ha−1). Therefore, the Merus ring could be a reliable and environmentally friendly alternative to acid injection to prevent the clogging of emitters in drip systems when saline water is used.

Remote Sensing and Assessment of Compound Groundwater Flooding Using an End-to-End Wireless Environmental Sensor Network and Data Model at a Coastal Cultural Heritage Site in Portsmouth, NH.

The effects of climate change in the forms of rising sea levels and increased frequency of storms and storm surges are being noticed across many coastal communities around the United States. These increases are impacting the timing and frequency of tidal and rainfall influenced compound groundwater flooding events. These types of events can be exemplified by the recent and ongoing occurrence of groundwater flooding within building basements at the historic Strawbery Banke Museum (SBM) living history campus in Portsmouth, New Hampshire. Fresh water and saline groundwater intrusion within basements of historic structures can be destructive to foundations, mortar, joists, fasteners, and the overlaying wood structure. Although this is the case, there appears to be a dearth of research that examines the use of wireless streaming sensor networks to monitor and assess groundwater inundation within historic buildings in near-real time. Within the current study, we designed and deployed a three-sensor latitudinal network at the SBM. This network includes the deployment and remote monitoring of water level sensors in the basements of two historic structures 120 and 240 m from the river, as well as one sensor within the river itself. Groundwater salinity levels were also monitored within the basements of the two historic buildings. Assessments and model results from the recorded sensor data provided evidence of both terrestrial rainfall and tidal influences on the flooding at SBM. Understanding the sources of compound flooding within historic buildings can allow site managers to mitigate better and adapt to the effects of current and future flooding events. Data and results of this work are available via the project's interactive webpage and through a public touchscreen kiosk interface developed for and deployed within the SBM Rowland Gallery's "Water Has a Memory" exhibit.

Hydrogeological Resolution Using Composite Geophysical Methods: A Case Study of Inland Salinity in Part of Agra, Uttar Pradesh India

ABSTRACT This manuscript is an attempt at utilizing a combination of varied Geophysical methods (n = 4) – Vertical Electrical Sounding (VES), Electrical Resistivity Tomography (ERT), Time Domain Electromagnetic (TEM), and Borehole logging for finer resolution of potential fresh groundwater and saline groundwater aquifer zones in marginal alluvial plains of Agra district, Uttar Pradesh state. A conceptual model of sub-surface aquifer disposition displaying zones of fresh and saline groundwater zones was prepared using an interpreted and processed multi-parameter dataset. A positive correlation was found between TEM (44.6 m), Well log data (43.0 m), VES data (47.2), and ERT data (45.0 m) demarcating the boundary up to which fresh groundwater potential lies from the ground surface. Conventional methods rely on resistivity values to identify groundwater potential zones, and a rough estimation of salinity can be carried out. Instead of the conventional VES method, the combination of aforesaid methods results in finer resolution and easier demarcation of fresh groundwater zones from those of saline zones. This method can be successfully reproduced to demarcate the extent of saline water ingress in coastal areas and finding freshwater lenses within inland saline aquifers.

Mathematical Modeling for Predicting Growth and Yield of Halophyte Hedysarum scoparium in Arid Regions under Variable Irrigation and Soil Amendment Conditions

Growing degree days (GDDs) and leaf area index (LAI) greatly influence the growth and yield of many crops grown in arid regions. Therefore, variation in LAI due to GDD can provide a theoretical basis for predicting crop growth, water consumption, plant development, and yield in arid agriculture via the development of mathematical growth models. This study described the relationship between plant biomass production and variation in LAI due to GDD in arid regions under different types of irrigation (fresh water and saline water) and soils amended with different substances (manure+sandy soil, compost+sandy soil, clay+sandy soil, and sandy soil). Mathematical models for LAI were established for GDDs. In addition, different water quality irrigation techniques were used as independent variables to calculate the LAI of halophytic plants (Hedysarum scoparium) in arid regions under different soil amendment treatments. Furthermore, mathematical models for plant biomass production were developed by using the LAI and GDDs. For this purpose, Logistic, Gaussian, modified Gaussian, and Cubic polynomial models were used. Modified Gaussian and Cubic polynomial models are the best among all developed models, but Cubic polynomial models are more suitable among all developed models because of their simple quadratic equations that can be solved by using the first derivative. It was observed that with increased salt concentration in the irrigation water, the growth of per plant production decreased. However, soil amendments like manure and compost enhance salt tolerance against salt stress and enable plants to sustain their growth. Furthermore, Hedysarum scoparium attains maximum LAI when its GDD is about 1117.5 °C under both irrigation regimes and in all soil amendment treatments. It was concluded that these predicted mathematical models can provide crucial insights for enhancing production in arid regions by using eco-friendly soil amendments to improve water use efficiency across diverse types of water irrigation.

Evaluating salt tolerance in fodder crops: A field experiment in the dry land

Abstract Freshwater scarcity and a shortage of agricultural land constitute the primary limiting factors affecting crop production in numerous arid and semi-arid regions across the globe. This study involves the introduction of three sorghum cultivars (Kaoliang, Sudan grass, and Sweet grass) from China into the dry land of Pakistan, with irrigation using different water qualities (fresh water and saline water) during the rainy season. Parameters including plant height, stem diameter, leaves per plant, number of tillers per plant, specific leaf area, aboveground biomass, below ground biomass, and yield per acre were measured. All plant species exhibited a reduction of 30–40% in their physiological functions, growth parameters, and yield under saline water irrigation compared to freshwater irrigation. Sweet grass and Sudan grass demonstrated higher yields under saline water irrigation compared to Kaoliang, although the overall yields of all three cultivars remained within an acceptable range, while using saline water irrigation. It was concluded that these three introduced sorghum cultivars are well-suited for cultivation in the arid region during the rainy season, particularly when irrigated with saline water. This study offers an eco-friendly approach to utilizing dry land resources for agricultural production, thereby assisting local communities in sustaining their livelihoods.

Effects of Biochar and Straw Return on Soil Microbial Community Characteristics and Functional Differences in Saline Water Drip Irrigation Cotton Fields

In arid areas, fresh water resources are insufficient, and agricultural water mainly depends on shallow saline groundwater. However, long-term saline irrigation will cause soil salt accumulation and soil environment deterioration, which is not conducive to crop growth. In this study, based on the long-term irrigation of fresh water (0.35 dS·m-1, FW) and saline water (8.04 dS·m-1, SW), biochar (3.7 t·hm-2, BC) and straw (6 t·hm-2, ST) were added to the soil by an equal-carbon design. The aim was to clarify the effects of biochar and straw returning on the physical and chemical properties and microbial community structure of salinized soil. The results showed that saline irrigation significantly increased soil water content, electrical conductivity, available phosphorus, and total carbon content but significantly decreased pH value and available potassium content. The contents of available phosphorus, available potassium, and total carbon in soil were significantly increased by biochar and straw returning, but the conductivity value of soil irrigated with saline water was significantly decreased. The dominant bacteria in each treatment were Proteobacteria, Actinomycetes, Acidobacteria, Chloromycetes, and Blastomonas. Saline water irrigation significantly increased the relative abundance of Blastomonas and Proteobacteria but significantly decreased the relative abundance of Acidobacteria and Actinobacteria. Under the condition of fresh water irrigation, the relative abundance of Chlorocurvula was significantly reduced by the return of biochar. Straw returning significantly increased the relative abundance of Proteobacteria but significantly decreased the relative abundance of Acidobacteria, Actinomyces, Chloromyces, and Blastomonas. Under saline irrigation, the relative abundance of Chlorocurvula and Blastomonas were significantly reduced by biochar return to field. Straw returning significantly increased the relative abundance of Proteobacteria but significantly decreased the relative abundance of Acidobacteria, Actinomyces, Chloromyces, and Blastomonas. LEfSe analysis showed that saline irrigation decreased the potential markers and functional numbers of soil microorganisms.Under saline irrigation, biochar returning increased the number of potential markers and functions of soil microorganisms. Straw returning to field increases the number of potential markers of soil microorganisms. RDA results showed that soil microbial community and functional structure were significantly correlated with EC1:5, SWC, and pH. Saline water irrigation will deteriorate the soil environment, which is not conducive to agricultural production, among which EC1:5, SWC, and pH are important factors driving changes in soil microbial community and functional structure. Using biochar and straw to return to the field can reduce the harm of salt to soil and crops, laying a foundation for improving agricultural productivity.

Effect of salinity and drip fertigation on maize (<i>Zea mays</i>) and water use efficiency

Climatic variability is immensely pressurised on freshwater availability in arid and semi-arid ecosystems, leading to poor quality water for crop production not becoming uncommon, especially in coastal ecosystems. A field experiment was conducted during winter (rabi) season of 2022–23 at the Saline Water Scheme at Agricultural College Farm, Acharya N. G. Ranga Agricultural University, Bapatla, Andhra Pradesh to assess the impact of saline water on maize growth, yield and water use efficiency under drip fertigation. The experiment consisted 8 treatments laid in randomized block design (RBD) with 4 replications. The utilization of the BAW irrigation method, together with the application of a prescribed quantity of fertilizer, resulted in the highest plant height and dry matter accumulation during all phases of crop growth. These outcomes were comparable to those achieved by using a combination of fresh water and saline water with an electrical conductivity of 2 dS/m. The maximum values for the number of kernels per cob (451), cob length (17.2 cm), cob weight (164.4 g), kernel yield (7.38 t/ha), stover yield (9.61 t/ha) and water use efficiency (18.5 kg/ha mm) of maize were observed under the irrigation treatment T4. The parameters exhibited their minimum values when irrigation was conducted using water with a salt level of 4 dS/m and no fertilizers were used. However, there was no statistically significant difference observed in the number of cobs per plant and harvest index of maize when saline water was used in conjunction with drip fertigation. In the context of maize cultivation, employing a cyclic irrigation technique that alternates between salty (EC 2–4 dS/m) and freshwater sources, in conjunction with recommended dose of fertiliser (RDF) has the potential to deliver comparable crop development, productivity, and economic benefits when compared to the use of freshwater sources alone.

Interactive Effects of Emitter Type, Water Salinity, and Deficit Irrigation on Red Cabbage (Brassica Oleracea L) with Evaluating Drip Irrigation System

Field research was carried out at Kirkuk Governorate (Altun Kopri district) near the village of Hasar Al- Kabeer for the agricultural season of 2022 to compare two types of GR and Turbo emitter and two levels of water salinity on yield (0.55 EC dSm-1), (4.40 EC dSm-1), with four levels of deficit irrigation (ETc 120%), (100% full irrigation) (75% ETc), and(0.50% Etc). The results were analyzed with a factorial split-split plot design, and the F-test and Duncan’s test determined the differences between factories and averages. The system was evaluated at the beginning of the experiment in comparison between GR and turbo emitter performance. Results were shown to outperform the GR emitter on the Turbo emitter in four qualities: coefficient of manufactured variety (% CV), uniformity of emitter flow (% Eu), uniformity field emission F.EU%, and absolute uniformity field emission F.Eua% with results of 0.01% 9.45% %,99.09%and 99.87 % The system was also evaluated in the middle of the experiment in comparison between fresh water and saline water in same qualities parameter. The results were shown by the superiority of fresh water over saline water as the results were (0.0379%), (0.0932%), (98.83%), (97.16%),(98.28),(98.93), and(99.85),(99.87)respectively. The most important results showed the superiority of the GR emitter interference treatment with freshwater at water stress level (100% ETc) in the total yield Mg ha-1 and plant height cm for red cabbage were 26.50 Mg ha-1 and 35.00 cm. Turbo emitter with saline water at 50% water stress given the best value (24.20 leaf plant -1).

The Effects of Zinc on Proprioceptive Sensory Function and Nerve Conduction

Zinc (Zn2+) is an essential element that can promote proper organ function, cell growth, and immune response; it can also, however, be present in too great a quantity. Zinc toxicity caused by overexposure may result in both minor and major physiological effects, with chronic exposure at low levels and acute exposure at high levels being harmful or even toxic. This investigation examines the effects of acute exposure to relatively high concentrations of Zn2+ on sensory nerve function and nerve conduction. A proprioceptive nerve in marine crab (Callinectes sapidus) limbs was used as a model to assess the effects of Zn2+ on stretch-activated channels (SACs) and evoked nerve conduction. Exposure to Zn2+ slowed nerve condition rapidly; however, several minutes were required before the SACs in sensory endings were affected. A depression in conduction speed and an increase followed by a decrease in amplitude were observed for the evoked compound action potential, while the frequency of nerve activity upon joint movement and stretching of the chordotonal organ significantly decreased. These altered responses could be partially reversed via extensive flushing with fresh saline to remove the zinc. This indicates that subtle, long-term exposure to Zn2+ may alter an organism’s SAC function for channels related to proprioception and nerve conduction.

Kinetic model of PFAS removal by semi-batch foam fractionation and validation by experimental data for K-PFOS

Adsorptive bubble separation techniques such as foam fractionation have recently been applied for the extraction of per- and polyfluoroalkyl substances (PFAS) from waters at both laboratory and operational scales. However, few authors have developed mathematical models of their removal of PFAS. This study presents a theoretical framework for the kinetics of PFAS removal from fresh and monovalent saline waters by a semi-batch foam fractionation process, by the mechanisms of adsorption, entrainment and volatilization, as a function of pertinent parameters including PFAS air-water adsorption, bubble radius, electrolyte concentration and ionic strength, PFAS volatility, and flow and geometric parameters. The freshwater model is validated for the removal of potassium perfluorooctane sulfonate (K-PFOS) using published experimental data (Meng, P. et al., Chemosphere, 2018, 203, 263–270). The proposed models provide quantitative tools for process design and the optimization of individual PFAS removal by semi-batch adsorptive bubble separation techniques such as foam fractionation.

Geochemistry of lacustrine carbonate rocks in southwestern Qaidam: Implications of silicate weathering and carbon burial triggered by the uplift of the Tibetan Plateau

Lacustrine carbonates are known to be one of the responses of the hydrosphere to aridification in terrestrial ecosystems. >8000 km2 of carbonate-rich deposits, up to 3000 m in thickness, developed in the western part of the Cenozoic Qaidam Basin. The detailed depositional mechanisms of these regional long-scale carbonates and the uplift linkage of the Tibetan Plateau are yet to be explored. Thus, in this study, the fine-grained analysis of carbonate-rich cores from the Pliocene Upper Youshashan Formation of the Qaidam Basin was performed using major, trace element, isotope, and lipid biomarker chemistry and statistical and correlation analyses. As per the results, it was found that carbonate minerals had an average content of 37.2%, consisted mainly of Fe-dolomite (Fe-dol) and calcite, and presented contents that were significantly and positively correlated with the carbonate oxygen isotope value. As the highly crystalline silicate debris flowing from the Altyn Tagh mountains accumulated in the lake basin, it formed high-content clay minerals and silicate, which coexisted through strong silicate weathering and released N, S, K, Na, and trace elements, providing the material basis for the carbonate richness and eutrophication of the fresh–saline lake ecosystem. Chemical weathering, aquatic organism burgeoning, and lake alkalinization coupled and promoted each other, which resulted in the widespread precipitation of carbonate rocks in the study area. Geochemical data suggest that carbonate minerals precipitated in sub-oxidized waters, while the organic matter was buried in reducing conditions during the early diagenetic stage. Further studies showed that sulfate-reducing bacteria mediated the mechanism of lacustrine dolomite genesis. After the freshwater silicate debris flow entered the lake, the sulfate-reducing bacteria consumed terrestrial organic matter to produce dolomite in a slightly salty water environment. In contrast, Fe-dolomite is produced by sulfate-reducing bacteria consuming the mixed organic matter from aquatic and early terrestrial sources in saline water. Although the uplift of the Tibetan Plateau has led to the aridification of the Eurasian continent, It has been proven to cause considerable burial of organic and inorganic carbon.

Plant Growth Promoting Rhizobacteria and Silica Nanoparticles Stimulate Sugar Beet Resilience to Irrigation with Saline Water in Salt-Affected Soils.

Combined stressors (high soil salinity and saline water irrigation) severely reduce plant growth and sugar beet yield. Seed inoculation with plant growth-promoting rhizobacteria (PGPR) and/or foliar spraying with silica nanoparticles (Si-NP) is deemed one of the most promising new strategies that have the potential to inhibit abiotic stress. Herein, sugar beet (Beta vulgaris) plants were treated with two PGPR (Pseudomonas koreensis MG209738 and Bacillus coagulans NCAIM B.01123) and/or Si-NP, during two successive seasons 2019/2020 and 2020/2021 to examine the vital role of PGPR, Si-NP, and their combination in improving growth characteristics, and production in sugar beet plants exposed to two watering treatments (fresh water and saline water) in salt-affected soil. The results revealed that combined stressors (high soil salinity and saline water irrigation) increased ion imbalance (K+/Na+ ratio; from 1.54 ± 0.11 to 1.00 ± 0.15) and declined the relative water content (RWC; from 86.76 ± 4.70 to 74.30 ± 3.20%), relative membrane stability index (RMSI), stomatal conductance (gs), and chlorophyll content, which negatively affected on the crop productivity. Nevertheless, the application of combined PGPR and Si-NP decreased oxidative stress indicators (hydrogen peroxide and lipid peroxidation) and sodium ions while increasing activities of superoxide dismutase (SOD; up to 1.9-folds), catalase (CAT; up to 1.4-folds), and peroxidase (POX; up to 2.5-folds) enzymes, and potassium ions resulting in physiological processes, root yield, and sugar yield compared to non-treated controls under combined stressors (high soil salinity and saline water irrigation). It is worth mentioning that the singular application of PGPR improved root length, diameter, and yield greater than Si-NP alone and it was comparable to the combined treatment (PGPR+Si-NP). It was concluded that the combined application of PGPR and Si-NP has valuable impacts on the growth and yield of sugar beet growing under combined stressors of high soil salinity and saline water irrigation.

Impacts of Coastal Shrimp Ponds on Saltwater Intrusion and Submarine Groundwater Discharge

AbstractShrimp aquaculture has expanded rapidly in coastal zones worldwide over the past few decades. Saline water stored in shrimp farm ponds can infiltrate into the underlying aquifer causing groundwater salinization and increased submarine groundwater discharge (SGD) to coastal water. However, little research has assessed salinization resulting from these shrimp ponds. To understand the impacts of shrimp farm irrigation on groundwater salinization and SGD, we numerically simulated a series of aquaculture management scenarios in a two‐dimensional conceptual coastal aquifer using a coupled surface‐subsurface approach. We characterized sensitivities to pond water salinity, pond water depth, and farm width. Salinization was assessed by three indicators (salinized area, infiltrated salt mass, and recovery rate), and three SGD indicators were evaluated (fresh SGD, saline SGD, and saltwater circulation rate). Our results show that pond water depth is the primary control on the mass of saltwater infiltration while farm width is the primary control for recovery rate. Pond water salinity and depth affect both fresh and saline SGD. We show that aquaculture is a previously unrecognized mechanism of salinization affecting coastal aquifer vulnerability and SGD. A regional graphical information system analysis shows transformation into aquacultural ponds could introduce considerable SGD variability spatially and temporally. These findings will enable coastal managers to better evaluate groundwater vulnerability in regions with expanding onshore aquaculture and demonstrates the impact of aquaculture on coastal groundwater resources and the need for further study to understand the impact of aquaculture across Asia and the globe.

Особенности развития личинок и молоди пиленгаса Liza haematocheilus (Temminck & Schlegel, 1845) = Mugil soiuy (Basilewsky, 1855) в искусственных условиях

Soiuy mullet of the family Mugilidae is a valuable commercial fish species introduced into the Azov-Black Sea basin. It is adapted to live both in fresh and oceanic saline waters; it fattens in shallow waters of bays and lagoons that warm up and cool down quickly and strongly and is one of the promising objects for artificial breeding. There are presented the research results on cultivating larvae and juveniles of soiuy mullet in 2017-2020 in the conditions of artificial reproduction at the experimental base of “Kerch” department of Russian Research Institute of Fish Industry and Oceanography (AzNIIRH) – Research Base Zavetnoe. The biological norms of larvae rearing to the end of metamorphosis were outlined. The larvae aged 4-12 days were fed only with zooplanktonic organisms. 10-12-day-old juveniles were fed with inert feed. There are given the data on development of eggs and juveniles of soiuy mullet in artificial conditions, main size and weight parameters, daily diets and amount of artificial feed used in its rearing from 
 5 to 120 days old. Using live feed in combination with artificial feed up to 30 days old is recommended. There are presented quantitative indicators on the expenditure of live and artificial feed and feed coefficients in soiuy mullet larvae farming until the completion of metamorphosis and yearlings. It has also been found that dietary intake of larvae considerably increases with growth, therefore it is expedient to work on using a wider range of artificial feed at earlier stages of rearing - in 10-15-day-old soiuy mullet larvae.

Green nanosilica enhanced the salt-tolerance defenses and yield of Williams banana: A field trial for using saline water in low fertile arid soil

Nanotechnology offers great opportunities for sustainable management of degraded soils and using of saline water. The use of green nanoagrochemicals (e.g., nanofertilizers) derived from plant biowastes is highly concerning from an agro-environmental point of view. The impacts of nanoagrochemicals on salt tolerance mechanisms of Williams banana (Musa spp.) plants under field conditions, particularly in soils with low fertility under salinity stress and low organic matter content, have not yet been verified. Therefore, in this study, a two-year field trial was conducted to investigate the impacts of green nanosilica (GNS) application on the enhancing the salt tolerance of Williams banana plants in arid sandy soil. Banana plants were irrigated with fresh Nile River water (EC = 0.53 dS m−1) or saline groundwater (EC = 4.12 dS m−1) and sprayed with GNS at doses of 0 mg L−1 (control), 150 mg L−1 (GNS1), and 300 mg L−1 (GNS2) in spring, summer, and autumn. Spraying the saline water-irrigated plants with GNS1 and GNS2 significantly increased the total fruit yield by 30% and 45% in the first year and by 21% and 38% in the second year and reduced the concentrations of Na+ in leaves by 32% and 36%, respectively, compared with the control. Moreover, the foliar application of GNS1 and GNS2 improved the total sugar content in the banana fruits under salinity stress by 42% and 50%, respectively. We assume that GNS application induced an increase in nutrient uptake and that antioxidant and osmoregulation compounds (e.g., proline and soluble carbohydrates) enhanced banana plant tolerance to salinity stress. Although the use of GNS reduced the negative effects of saline irrigation water, banana plants that were irrigated with Nile River water remained significantly better than the saline ground water. In conclusion, the foliar application of GNS improved the productivity and quality of Williams banana fruit in sandy poor soils and enhanced their tolerance to salinity stress, which provides opportunities to expand banana cultivation using saline water in low fertile sandy arid soils. These findings might be an aid for sustainable management of degraded sandy arid soils and reusing of saline water.

Effects of Cotton Stalk Returning on Soil Enzyme Activity and Bacterial Community Structure Diversity in Cotton Field with Long-term Saline Water Irrigation

Long-term saline water irrigation will increase soil salinity, adversely affect soil physical and chemical properties, and change the diversity of soil bacteria. Straw returning can improve the soil microenvironment and subsequently affect soil enzyme activity and bacterial community structure diversity. This experiment used two types of irrigation water salinity:fresh water (FW, 0.35 dS·m-1) and saline water (SW, 8.04 dS·m-1). Under each irrigation water salinity, the amount of cotton straw applied was 0 and 6000 kg·hm-2 (represented by FWST and SWST, respectively). The results showed that:compared with those under fresh water irrigation, saline water irrigation significantly increased the soil salt, bulk density, total carbon, and available phosphorus but significantly decreased available potassium content. Under saline water irrigation, straw returning significantly increased the soil total carbon, total nitrogen, available potassium, and available phosphorus but reduced soil bulk density. Compared with those under fresh water irrigation, soil sucrase, alkaline phosphatase, and catalase activities under saline water irrigation decreased by 57.24%, 35.15%, and 3.91%, respectively, whereas urease activity increased by 26.73%. However, straw returning significantly increased sucrase, alkaline phosphatase, and catalase activities but decreased urease activity. Saline water irrigation decreased the relative abundance of Acidobacteriota, Actinobacteriota, Bacteroidota, Verrucomicrobiota, and Firmicutes and increased the abundance of Gemmatimonadota and Myxococcota. Under saline water irrigation, straw returning significantly increased the relative abundance of Actinobacteriota, Bacteroidetes, Firmicutes, Crenarchaeota, Sphingomonas, Dongia, and Steroidobacter. NMDS results also showed that saline water irrigation and straw returning changed the bacterial community structure. In conclusion, straw returning can improve soil nutrient content, reduce soil bulk density and salinity, and then change soil enzyme activity and bacterial community structure diversity. The change in soil bacterial community composition was mainly affected by soil salinity and bulk density. Therefore, straw returning can improve soil fertility and help maintain the health of soil ecosystem. This study revealed a relationship between soil enzyme activities and bacterial communities, which provides a theoretical basis and mechanism for applying cotton stalk to regulate the soil enzyme and micro-ecological environment.

Saline Water Impact on Water Use Efficiency of Bitter Melon (Momordica charantia L) Using Drip Irrigation

Water shortage is a real problem in many parts of the world and finding alternative solutions such as the application of saline water in cropping systems is highly appreciated. Research on drip irrigation and soil salinity is still inadequate, and their effect on crop yield and water use efficiency (WUE) is a huge challenge for small farmers. The present study was conducted in Malir, a semiarid region in the Sindh province of Pakistan. The purpose was to estimate the effects of two different qualities of irrigation water including fresh quality water (IT1 0.56 dS m−1) and saline groundwater (IT2 2.89 dS m−1) on WUE using drip irrigation technology in 2018–19. The experimental design was complete randomized block design (RCBD) with two treatments of irrigation: (1) freshwater (IT1) with 0.56 dS m−1 electrical conductivity and (2) saline water (IT2) with 2.89 dS m−1 electrical conductivity. The average biomass and crop yield under IT1 were 10.2 t.ha−1 and 7.4 t.ha−1, respectively, and were found higher than those under IT2 (7.3 t−1 and 4.2 t.ha−1, respectively). Hence, both the treatments remained equally effective in season 1 as compared to season 2 ( p ≤ 0.05 ). The WUE of bitter melon under IT1 was 1.60 and 1.56 kg.m−3 in seasons 1 and 2, respectively, and was higher than those under IT2 which were observed 1.21 and 1.07 kg.m−3 in seasons 1 and 2, respectively.

Growth-stage-sensitivity of four HYV rice cultivars to irrigation water salinity

Application of fresh water at the salinity-sensitive growth stage(s) and saline water of tolerable salinity level at the less sensitive stage(s) may be an effective irrigation technique for rice (Oryza sativa L.) cultivation in fresh water-scarce salt-affected areas. However, implementation of this technique requires adequate prior information on the sensitivity of growth stages of the rice cultivars to salinity of irrigation water. The objective of this study was therefore to identify the sensitivity of growth stages of Binadhan-8, Binadhan-10, BRRI dhan28 and BRRI dhan47 to salt stress by irrigating the crops with fresh water (control), and saline water of 6, 9 and 12 dS m1 at establishment, tillering, panicle formation, flowering, maturity and all growth stages of the crops. The experiment was laid out in a split-split pot arrangement following a completely randomized design (CRD) with three replications. The establishment and flowering stages of the rice cultivars were found to be the most sensitive to salt stress. Therefore, irrigation at these growth stages with fresh water and at the other growth stages with saline water would be an appropriate strategy for cultivation of the tested rice cultivars in fresh water-scarce saline areas like the coastal saline region of Bangladesh.

Sensitivity of ponies to sodium in the drinking water.

Horses lose high amounts of Na through excessive sweating. These fluid losses can often not be replaced completely by voluntary water intake, requiring saline solutions as rehydration therapy to regain electrolyte balance. The experiment aimed to evaluate the sensitivity and tolerance of Shetland ponies towards different Na concentrations in their drinking water and contained three phases: (1) control: only fresh water provided; (2) pairwise-preference test: choice between fresh water and saline solution with stepwise increasing sodium chloride (NaCl) concentration (0.25%, 0.5%, 0.75%, 1.0%, 1.25%, or 1.5%); and (3) free-choice test: six simultaneously provided buckets containing NaCl concentrations of 0%, 0.25%, 0.5%, 0.75%, 1.0%, or 1.25%. During the pairwise test, the ponies did not distinguish between fresh and 0.25% NaCl-water but demonstrated clear preference for 0.5%, whereas >0.75% NaCl was avoided/rejected. During the free-choice test, a pronounced preference of fresh over saline water was exhibited. The Na intake via salt lick was not reduced as response to higher Na intakes via water. The ponies exhibited a remarkable sensory discrimination capacity to detect different NaCl concentrations in their drinking water. The acceptance of solutions with low NaCl levels (0.25/0.5%) without adverse effects demonstrates potential as rehydration solution for voluntary intake.

Datasets for the Determination of Evaporative Flux from Distilled Water and Saturated Brine Using Bench-Scale Atmospheric Simulators

Evaporation from fresh water and saline water is critical for the estimation of water budget in the Canadian Prairies. Predictive models using empirical field-based data are subject to significant errors and uncertainty. Therefore, highly controlled test conditions and accurately measured experimental data are required to understand the relationship between atmospheric variables at water surfaces. This paper provides a comprehensive dataset generated for the determination of evaporative flux from distilled water and saturated brine using the bench-scale atmospheric simulator (BAS) and the subsequently improved design (BAS2). Analyses of the weather scenarios from atmospheric parameters and evaporative flux from the experimental data are provided.