Effects Of Irrigation Water Salinity Research Articles

Application of Silica Nanoparticles Improved the Growth, Yield, and Grain Quality of Two Salt-Tolerant Rice Varieties under Saline Irrigation.

Salt stress significantly reduces rice yield and quality and is a global challenge, especially in arid and semi-arid regions with limited freshwater resources. The present study was therefore conducted to examine the potential of silica nanoparticles (SiO2 NPs) in mitigating the adverse effects of saline irrigation water in salt-tolerant rice. Two salt-tolerant rice varieties, i.e., Y liangyou 957 (YLY957) and Jingliangyou 534 (JLY534), were irrigated with 0.6% salt solution to simulate high-salt stress and two SiO2 NPs were applied, i.e., control (CK) and SiO2 NPs (15 kg hm-2). The results demonstrated that the application of SiO2 NPs increased, by 33.3% and 23.3%, the yield of YLY957 and JLY534, respectively, compared with CK, which was primarily attributed to an increase in the number of grains per panicle and the grain-filling rate. Furthermore, the application of SiO2 NPs resulted in a notable enhancement in the chlorophyll content, leaf area index, and dry matter accumulation, accompanied by a pronounced stimulation of root system growth and development. Additionally, the SiO2 NPs also improved the antioxidant enzyme activities, i.e., superoxide dismutase, peroxidase, and catalase activity and reduced the malondialdehyde content. The SiO2 NPs treatment effectively improved the processing quality, appearance quality, and taste quality of the rice. Furthermore, the SiO2 NPs resulted in improvements to the rapid viscosity analyzer (RVA) pasting profile, including an increase in peak viscosity and breakdown values and a reduction in setback viscosity. The application of SiO2 NPs also resulted in a reduction in crystallinity and pasting temperature owing to a reduction in the proportion of B2 + B3 amylopectin chains. Overall, the application of silica nanoparticles improved the quality of rice yield under high-salt stress.

Effect of Irrigation Water Salinity, Sowing Techniques and Mulching on Physio-Biochemical Traits of Fodder Sorghum

Effect of Irrigation Water Salinity, Sowing Techniques and Mulching on Physio-Biochemical Traits of Fodder Sorghum

Effect of Tomato Grafting onto Novel and Commercial Rootstocks on Improved Salinity Tolerance and Enhanced Growth, Physiology, and Yield in Soilless Culture

Grafting high-yielding tomato varieties onto stress-tolerant rootstocks can mitigate the adverse effects of saline water irrigation on plant tomato productivity in arid regions like Saudi Arabia. This study investigates the efficacy of grafting tomatoes onto both novel and commercial rootstocks to enhance salinity tolerance and its impact on growth, physiological parameters, and yield in a soilless culture system. The experiment involved two water quality levels, 2 (S1) and 4 (S2) dS m−1, two growth media types, volcanic rock (M1) and sand (M2), and six grafting treatments: Tone Guitar F1 non-grafted (G1) (commercial scion), grafted onto itself (G2), Tone Guitar F1* Maxifort F1 (G3) (commercial rootstock), and grafting the scion onto three novel rootstocks, X-218 (G4), X-238 (G5), and Alawamiya365 (G6). Growth, physiology, photosynthetic pigments, and yield improved with lower salinity (2 dS m−1) in volcanic rock and with the grafting treatments (G2–G6) compared to the non-grafted treatment (G1). The best results were achieved with the S1M1G5 treatment, where yield increased by 53% compared to the lowest yield in non-grafted plants grown in sand under higher salinity (S2M2G1). All studied traits were adversely affected under high salinity (S2) in sandy media, with the G1 treatment resulting in the lowest values for these traits.

Effect of some Natural Compounds on Reducing the Effect of Saline Water Irrigation on Marjoram Plants

Effect of some Natural Compounds on Reducing the Effect of Saline Water Irrigation on Marjoram Plants

Different Effects of Irrigation Water Salinity and Leaching Fractions on Pepper (Capsicum annuum L.) Cultivation in Soilless Culture

Different Effects of Irrigation Water Salinity and Leaching Fractions on Pepper (Capsicum annuum L.) Cultivation in Soilless Culture

Investigating foliar application of bulk and nanoparticles titanium dioxide on fennel productivity to mitigate the negative effects of saline irrigation water

BackgroundFennel essential oils are fragrance compounds used in food and pharmaceutical sectors. One of the major impediments to expansion of fennel farming in Egypt's reclamation areas is saline water. Titanium dioxide (TiO2) or TiO2 nano particles (TiO2NP) can be utilized to boost the yield of aromatic plants cultivated under saline irrigation water. Saline water, particularly which contains sodium chloride can harm fennel plant; consequently, it was predicted that fennel production would fail in Egypt's reclaimed area, where the primary source of irrigation is groundwater consisting sodium chloride. This study sought to help fennel respond to sodium chloride by applying Ti forms to their leaves in order to reduce the detrimental effects of sodium chloride on them for expanding their production in the newly reclamation areas as a natural source of essential oil. Ti forms were applied as foliar application at 0, 0.1, 0.2 TiO2, 0.1 TiO2NP, and 0.2 TiO2NP, mM under irrigation with fresh water (0.4 dS m−1), or saline water (51.3 mM or 4.7 dS m−1).ResultsPlants exposed to 0.1 mM TiO2NP under fresh water resulted in the maximum values of morphological characters, estragole, oxygenated monoterpenes and photosynthetic pigments; while those subjected to 0.1 mM TiO2NP under saline water gave the greatest values of essential oil, proline, antioxidant enzymes and phenols. The greatest amounts of soluble sugars were recorded with 0.2 mM TiO2NP irrigated with saline water. Plants subjected to 0 mM TiO2 under saline water produced the greatest values of flavonoids, hydrogen peroxide and malondialdehyde.ConclusionTo mitigate the negative effects of salty irrigation water on fennel plant production, TiO2NP application is suggested as a potential strategy.

Yield and Bio-Chemical Parameters of Onion (Allium Cepa L.) and Consequences of Saline Irrigation Water on It

At Department of Agricultural Chemistry and Soil Science a pot experiment was conducted during the rabi, season of 2017-18. Department of Agricultural Chemistry and Soil Science situated at College of Agriculture, Junagadh Agricultural University, Junagadh, Gujarat. The objective of the study is to assess the consequences of saline irrigation water on yield of Onion (Allium Cepa L.) varieties. The study also possess the growth and nutrients composition of Onion (Allium Cepa L.) varieties and effect of saline irrigation water on it. Four levels of salinity are contained viz., < 2.0, 4.0, 6.0 and 8.0 dS m-1. GJWO-3, GJRO-11, Talaj red, Pilli patti and PWF-131 these five varieties comprised in factorial completely randomized design with three replications. It found that the yield of chlorophyll a (5.77 mg/gf.wt), chlorophyll-b (4.22 mg/gf.wt), and total chlorophyll were significantly influenced by different levels of salinity, whereas; yield of fresh straw (37.03 g/pot), bulb (37.49 g/pot), RWC, proline (0.96 µmole/gf.wt), were significantly influenced among different varieties of onion tested.

Effects of Biochar and Municipal Solid Waste Compost on Soil Physical Quality and Productivity Index Under Sorghum Cultivation Irrigated with Saline Water

ABSTRACT Amending soil with different materials is gaining acceptance as an effective and inexpensive technique for reclamation of salt-affected soils. The main idea of this study was to investigate the effects of biochar, compost of municipal solid waste and different water salinities level on soil physical quality (SDexter) and soil productivity index (SPI). The treatments were as followed: Control: Soil without biochar or compost and irrigated with tap water, S1: Soil without biochar or compost and irrigated with saline water (EC = 4.5 dS m−1), S2: Soil without biochar or compost and irrigated with saline water (EC = 9 dS m−1), B: Soil amended with 1.5%w/w biochar and irrigated with tap water, B+S1: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 4.5 dS m−1), B+S2: Soil amended with 1.5%w/w biochar and irrigated with saline water (EC = 9 dS m−1), C: Soil amended with 1.5%w/w compost and irrigated with tap water, C+S1: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 4.5 dS m−1), C+S2: Soil amended with 1.5%w/w compost and irrigated with saline water (EC = 9 dS m−1). Soil water characteristic curve (SWCC), Field capacity (FC), Plant wilting point (PWP), Plant available water (PAW), Dexter’s index of soil physical quality (SDexter) and SPI were examined in a greenhouse experiment. The SPI was calculated by integrating the effects of six soil quality indices: plant available water, organic matter (OM), Electrical conductivity (EC), pH, Bulk density (BD) and Root weighting factor (RF) for all treatments were calculated. The results showed that the B treatment had a slightly higher effect on SWCC. The applied B and C treatments caused insignificant increase in PAW relative to the control. In addition, application of biochar or compost to soil significantly increased the SDexter. The application of C treatment had insignificantly higher value of SDexter compared to other treatments. Compared with the control, SPI was significantly higher for the B and C treatments. Overall, the application of biochar/compost minimized the destructive effects of saline irrigation water and improved the quality of the salt-affected fine-textured soil.

Effect of irrigation water salinity on morphological and physiological characteristics of celery

The objective of this study was to investigate the effects of salinity levels of irrigation water on the morphological and physiological characteristics of celery (Apium graveolens L.) during early seedling development. Celery seedlings of Balena cultivar were grown with saline irrigation water consisting of different NaCl levels (0, 50, 100, 150, 200, 250, and 300 mM). The results showed that increasing salt stress inhibited plant growth by destroying physiological parameters. Each increase in NaCl resulted in a decrease in the length, diameter, number, and fresh and dry weight of leaves. Dry matter, chlorophyll content, leaf temperature, and turgor loss improved when NaCl levels were increased; however, salinity caused a reduction in leaf relative water content. Leaf fresh and dry weights were lower under salt stress, even at 50 mM NaCl. Leaf temperature was higher in plants grown under salinity and reached the maximum level at 100 mM NaCl. The stomata on the abaxial side of the leaves were smaller but more numerous under salinity than in the control plants. It was concluded that celery’s plant growth was significantly influenced by salinity and that it could endure salinity lower than 100 mM NaCl.

Integrated effect of saline water irrigation and phosphorus fertilization practices on wheat (Triticum aestivum) growth, productivity, nutrient content and soil proprieties under dryland farming

Wheat (Triticum aestivum) is the most common and oldest crop in Morocco and MENA region countries, cultivated both for human and animal nutrition. In Morocco, the irrigated perimeter of Tadla is the major wheat growing area affected by soil and groundwater salinity problematic. Previous studies have shown that phosphorus (P) fertilization can mitigate the negative effects of salinity on different crops. Thus, field experiments from the combination of four levels of irrigation water salinity and three P-fertilization rates were conducted during two successive growing seasons (between 2019 and 2021) at the National Institute of Agronomic Research (INRA), Tadla, Morocco. Our main objective was evaluating the potential of P-fertilization to improve wheat growth, productivity and quality under saline water irrigation practices. The crop simulation model APSIM, was also tested to assess its performance in simulating wheat growth, productivity, phosphorus and nitrogen nutrient dynamics in soil-plant system under saline conditions. Results showed that appropriate P-fertilization under saline conditions contributed to minimize the effect of salinity and improved wheat growth and production. Also, it was found that increasing P-fertilization improved nutrient uptake, and consequently the plant nutrient content. A good agreement between the measured and APSIM model simulated growth and yield state variables, as well as the plant and soil-N content. However, a model uncertainty and relevant limitations in simulating plant- and soil-P content output were identified and discussed. Overall, our finding suggests that appropriate P-application minimizes the adverse effects of high soil salinity and can be adopted as a coping strategy in wheat cultivation under saline water irrigation practices.

The Effects of Irrigation Water Salinity on the Synthesis of Photosynthetic Pigments, Gas Exchange, and Photochemical Efficiency of Sour Passion Fruit Genotypes.

The objective of this study was to evaluate the synthesis of photosynthetic pigments, gas exchange, and photochemical efficiency of sour passion fruit genotypes irrigated with saline water under the conditions of the semi-arid region of Paraíba state, Brazil. The experiment was conducted at the experimental farm in São Domingos, PB. A randomized block design was adopted, in a 5 × 3 factorial scheme, with five levels of electrical conductivity of irrigation water-ECw (0.3, 1.1, 1.9, 2.7, and 3.5 dS m-1)-and three genotypes of sour passion fruit (Gigante Amarelo-'BRS GA1'; Sol do Cerrado-'BRS SC1'; and Catarina-'SCS 437'. The increase in the electrical conductivity of irrigation water negatively affected most of the physiological characteristics of the sour passion fruit at 154 days after transplanting. Significant differences were observed between sour passion fruit genotypes when its tolerance was subjected to the salinity of irrigation water. There was an increase in the percentage of damage to the cell membrane with the increase in the electrical conductivity of irrigation water, with maximum values of 70.63, 60.86, and 80.35% for the genotypes 'BRS GA1', 'BRS SC1', and SCS 437', respectively, when irrigated with water of 3.5 dS m-1. The genotype 'BRS Sol do Cerrado' showed an increase in the synthesis of photosynthetic pigments when irrigated with water of 3.5 dS m-1, with maximum values estimated at 1439.23 μg mL-1 (Chl a); 290.96 μg mL-1 (Chl b); 1730.19 μg mL-1 (Chl t); and 365.84 μg mL-1 (carotenoids). An increase in photosynthetic efficiency parameters (F0, Fm, and Fv) of the genotype 'BRS Gigante Amarelo' was observed when cultivated with water with high electrical conductivity (3.5 dS m-1).

Acceptable Salinity Level for Saline Water Irrigation of Tall Wheatgrass in Edaphoclimatic Scenarios of the Coastal Saline–Alkaline Land around Bohai Sea

Saline water irrigation contributes significantly to forage yield. However, the acceptable salinity levels for saline water irrigation of tall wheatgrass remains unclear. In this study, field supplemental irrigations of transplanted-tall wheatgrass with saline drainage waters having salinities of electrical conductivity (ECw) = 2.45, 4.36, 4.42, and 5.42 dS m−1 were conducted to evaluate the effects of saline water irrigation on forage yield and soil salinization. In addition, the effects of plastic film mulching, fertilization, and saline water irrigation on sward establishment of seed-propagated tall wheatgrass were determined. Finally, a pot experiment was carried out to confirm the above field results. The results showed that two irrigations with ECw = 2.45 and 4.36 dS m−1 saline waters produced the highest dry matter yield, followed by one irrigation with ECw = 4.42 or 5.42 dS m−1. After rainfall leaching, the soil EC1:5 was reduced by 41.7–79.3% for the saline water irrigation treatments. In combination with saline water irrigation, plastic film mulching promoted sward establishment and enhanced the plant height and dry matter yield of seed-propagated tall wheatgrass, while fertilization played a marginal role. However, two irrigations with ECw = 7.13 and 4.36 dS m−1 saline waters resulted in rates of 3.2% and 16.0% of dead plants under the mulching and no mulching conditions, respectively. Furthermore, a pot experiment demonstrated that irrigation with ECw = 5.79 dS m−1 saline water led to the lowest reduction in forage yield and the highest crude protein content in leaves. However, the plants irrigated with ECw ≥ 6.31 dS m−1 saline water enhanced soil salinity and reduced the plant height, leaf size, and gas exchange rate. Conclusively, one irrigation with ECw ≤ 5.42 dS m−1 and SAR ≤ 36.31 saline water at the end of April or early May could be acceptable for tall wheatgrass production and minimize the soil salinization risk in the coastal saline–alkaline land around the Bohai Sea.

The Effect of Irrigation Water Salinity, Organic Matter, and Zinc Nano-Fertilizer on the Productivity of Sunflower (Helianthus annuus L.)

In accordance with the randomized full block design, In the Al-Mahaweel district, Al-Imam hand, and Al-Birawi region, a field experiment was conducted in a soil with a texture of silty clay loam categorized as the primary typic torrifluvent group (RCBD), Examining the effects of irrigation water quality, organic matter, the amount of zinc nano-fertilizer sprayed on the plant, and the interaction of the research components on sunflower crop production using a split plot experiment with three replications, Three separate factors were used in the experiment: irrigation with four various amounts of organic fertilizer (zero), 20 tons/ha of cow and sheep dung, and three different concentrations of zinc nanofertilizer (0, 1.5, and 3 g). Organic matter significantly improved the yield characteristics of sunflowers, such as disc diameter, number of seeds per disc, weight of 500 seeds, and overall yield, as compared to spraying with nano-Zinc. The three elements’ interplay significantly affected sunflower productivity. On March 5, 2022, the seeds were sown using cork dishes and a midwife-led method. The seeds were luleo varieties from a French breeder. The midwives were transferred to the permanent location after 30 days. The findings showed that increasing the salt content of the irrigation water significantly decreased the values of disc diameter, number of seeds per disc, weight of 500 seeds, and overall yield of sunflower plants.

Comparative Study of the Impact of Saline Water Irrigation on Tomato Yield, Quality and Growth in Andhra Pradesh, India

Tomato (Lycopersicon esculentum Mill.) belonging to the family Solanaceae, is one of the most important, popular, nutritious, and palatable vegetables grown in Andhra Pradesh. It plays a vital role in providing a remarkable quantity of vitamin-A and vitamin-C in human diet. Tomato is cultivated all over Andhra Pradesh due to its adaptability to wide range of soil and climate. Saline water resources are abundant in the most areas of India. Most of these resources still have not been effectively utilized. The present investigation was conducted on the effects of saline water irrigation on tomato yield, quality and growth at the Research Farm, Department of Agricultural Engineering, Aditya Engineering College, Surampalem, East Godavari district, Andhra Pradesh. Saline water differing in Electrical Conductivity (EC) 6ds/m and 4ds/m was supplied to the plant after the seedlings. The objective of this work is to compare the effect of tomato crop under drip irrigation by three different treatments. First treatment is of fresh water under drip irrigation. Second treatment is of Nacl+water with an EC of 6ds/m under controlled irrigation in the ratio 2.5:7.5. Third treatment is of Nacl+water with an EC of 4ds/m under controlled irrigation in the ratio 1.5:8.5 of the tomato variety Pusa F1 hybrid is used for the experiment. Growth of crop includes plant height, number of fruits, number of leaves, fruit length, fruit diameter and fruit weight. The healthy growth that is 69.4cm plant height, 26 leaves per plant, 34 fruits per plant, 7.8 cm fruit length, 5.4 cm diameter of fruit and 89.4 g of average fruit weight and maximum score (4.86 out of 5) in organoleptic test were obtained in (T-1) i. e. drip irrigation. Although salinized tomato fruits were smaller than non-salinized control fruits, they have increased soluble solids, high sugar content, which all are highly requested qualities by the processing tomato industry. Current research concludes that the fresh water irrigation T-1 recorded the high-water use efficiency and saline water irrigation treatments (T2&T3) having less water use efficiency may be due to the plants suffering with more soil moisture stress due to osmotic pressure build up by the saline water irrigation.

An Incubation Experiment on Screening of Black Gram Varieties for Tolerance to Saline Irrigation Water

Water is a second most important resource in agriculture followed by land. The water availability for irrigation is often scarce, is one of the most critical input for agriculture production in most areas. Productivity in these areas can be enhanced by better management of rainwater and /or development of groundwater. So the present investigation was carried out to study the effect of saline water irrigation on the growth of blackgram. The various treatment included in the study were three ruling varieties of blackgram as factor V viz., V1- VBN 6, V2- VBN 4 and V3- VBN 3 and four salinity levels as factor S viz., S1-EC-3 dS m-1 and Sodium Absorption Ratio (SAR) - 4; S2-EC- 3 dS m-1 and SAR-6; S3-EC-3 dS m-1 and SAR-8; S4-EC-6 dS m-1 and SAR-6. The experiment was laid out in a Factorial Completely Randomized Design (FCRD) with three replications. The results of the study concluded that the soil application of saline water (EC-3 dS m-1 and SAR-4) irrigation to saline tolerant blackgram variety VBN 3 (S1V3) was identified as best treatment combination to realize the maximum germination of blackgram under saline water irrigation.

Effect of Application Different Combinations of Phosphogypsum and Humic Acids Mixed With Saline Irrigation Water on Broccoli Yield and NPK Concentration

Long-term irrigation with saline water causes detrimental effects on the soil-crop system. The study aimed to determine the best combination of Phosphogypsum and humic acid can mitigate the negative effects of saline water irrigation on broccoli growth. Therefore, two-factorial field experiment was conducted according to a randomized complete block design with three replications during autumn season of 2021 in Fallujah district /Anbar governorate in sandy loam soil. The first factor included three levels of saline water irrigation, namely 2.5, 5.0 and 7.0 dS.m-1. while the second factor involved three levels of humic acids i.e., 0.0, 0.25 and 0.50 g/l mixed with three levels of phosphogypsum that is 0.0, 0.25 and 0.50 g/l. Fruits weight, height, yield, plant nitrogen content, plant phosphorus, and plant potassium content were measured. The results showed that the combinations under study ( humic acids and phosphogypsum) had a crucial role in reducing the negative effects of irrigation salinity. Moreover, the macronutrients availability increased with increasing humic acids concentration in irrigation water. The observed results show a significant increase in the weight of broccoli fruit and yield at T8 by giving 325 g. plant-1and 8.66 t.h-1 respectively under effect of the combination under study. Also, the studied combinations led to increase the N,P,and K concentration in plant tissues. Where the highest observed averages of nitrogen and potassium were 3.96% and 2.56% at T8 treatment. While The highest concentration of phosphorus was observed at treatment T9 reached 0.47%.

CHERRY TOMATO CULTIVATION UNDER DIFFERENT LEVELS OF IRRIGATION WATER SALINITY AND ROOT MANAGEMENT SYSTEM

The use of saline water is a challenge of modern agriculture since the use of this type water reduces crop quality and yield. From this perspective, this study aimed to analyze the performance of cherry tomato under different levels of irrigation water salinity and partial root-zone irrigation. The experiment was conducted in a plant nursery at the Engineering and Agricultural Sciences Campus of the Federal University of Alagoas, in Rio Largo, Alagoas, Brazil. The experimental design was completely randomized, in a 4 x 2 factorial arrangement corresponding to four levels of irrigation water salinity (0.5 (control), 1.5, 2.5, and 3.5 dS m-¹) and two root management systems (with and without root system division), with five replications. The plants were evaluated for growth, dry mass accumulation, and yield. The irrigation water salinity of 3.5 dS m-1 intensely reduces the plant height, number of fruits, and shoot dry mass of cherry tomato. The shoot fresh mass of cherry tomato was reduced by with root system division. However, this treatment increased the plant height and the number of fruits per plant. Root system division in cherry tomato plants mitigates the deleterious effects of irrigation water salinity up to the electrical conductivity of 1.5 dS m-1, especially on the fruit mass per plant.

Effect of Irrigation Water Salinity on Soil Characteristics and Microbial Communities in Cotton Fields in Southern Xinjiang, China

Irrigation with saline water is a possible solution to alleviate freshwater shortages. The long-term use of saline water for irrigation requires consideration of the influence of salt on the environmental conditions of the soil. The objective of this field study was to determine the effects of three continuous years of saline water irrigation on physiochemical properties and microbial communities in drip-irrigated cotton fields. The three total dissolved solid (TDS) levels of irrigation water treatments were (i) 1 g L−1 (fresh water, FWI), (ii) 3 g L−1 (brackish water, BWI), and (iii) 7 g L−1 (salt water, SWI). After three years, the electrical conductivity (EC), sodium adsorption ratio (SAR), and contents of K+, Na+, Mg2+, Cl−, and SO42− in the SWI treatment were significantly higher than those in the FWI and BWI treatments, but there were no significant differences in EC and K+ between the FWI and BWI treatments. BWI treatment significantly increased microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), urease, and sucrase contents. The diversity and abundance of bacteria and fungi were not affected by saline water irrigation, but the microbial community structure was altered. Saline water irrigation resulted in an elevation in the bacterial abundance of the phylum Chloroflexi and a decline in Proteobacteria and Actinobacteria. For fungi, the abundance of the phylum Ascomycota in the BWI treatment was greater than that in the FWI and SWI treatments. Linear discriminant analysis effect size (NMDS) results indicated clear variation in the microbiota profiles between the FWI, BWI, and SWI treatments for bacteria. Regarding the fungal microbiota profiles, the BWI and SWI treatments had similar microbiota profiles but were different from the FWI treatment. The number of bacterial biomarkers gradually increased with increasing total dissolved solids of irrigation water, while the number of fungal biomarkers gradually decreased. Additionally, cotton yield was significantly and positively correlated with the observed species of fungi, while it was significantly and negatively correlated with EC. Redundancy analysis (RDA) showed that bacterial community structure was regulated by SAR and fungal community structure was regulated by soil salinity and bulk density (BD). Future research will need to look into how the structure of the microbial community and the associated functional microorganisms are gradually changing with increased irrigation frequency under saline irrigation, as well as explore and screen for advantageous functional microorganisms.

Purslane (Portulaca oleracea L.) salt tolerance assessment

ABSTRACT The present study was aimed to evaluate the effect of irrigation water salinity on some agronomic and physiological attributes of purslane (Portulaca oleracea L.) and its tolerance to salinity stress. The treatments included seven levels of electrical conductivity of irrigation water (0.6 (control), 3, 6, 9, 12, 15, and 18 dSm−1) arranged in the form of a completely randomized design with three replications. The results showed that salinity stress successively decreased agronomic attributes such as root, shoot, and stem dry weight, plant height and leaf area. Physiological attributes such as relative water content as well as ion leakage differently responded to salinity stress. Relative water content response to salinity followed a quadratic regression model with the maximum of 81% at electrical conductivity of 6.87 dSm−1 and the minimum of 65% at highest salinity level of 18 dSm−1. Following an exponential regression model, ion leakage remained relatively the same till irrigation water salinity of 15 dSm−1 and reached to the maximum of 78% at highest irrigation water salinity of 18 dSm−1. In addition, shoot potassium content of purslane under non saline conditions equaled to 11% that was around 10 times more than the typical of potassium sufficient concentration for adequate growth. Moreover, with increasing salinity stress, shoot potassium content decreased to 7% at highest salinity level of 18 dSm−1 of irrigation water. However, with increasing irrigation water salinity, sodium shoot content of purslane was increased from 1.9% at the lowest salinity stress to 6.7% at the highest salinity stress. Based on the linear and nonlinear models, 10% of purslane biomass reduction occurred at soil electrical conductivity of around 10 dSm−1. In addition, 25 and 50% yield reduction observed at 16 and 25 dSm−1 of electrical conductivity of soil saturated paste. Therefore, purslane can be considered as a very salt tolerant plant, halophyte, and can successfully grow in soils with electrical conductivities not suitable for most crops.

Impacts of Saline Water Irrigation on Soil Respiration from Cotton Fields in the North China Plain

Saline water irrigation has been widely used for crop production where agriculture is short of freshwater. However, information about the response of soil respiration to saline water irrigation is limited. To identify the effect of saline water irrigation on soil respiration, the experiment based on long-term saline water irrigation cotton fields (since 2006) was conducted in the Heilonggang area in 2021. Five salinity levels in irrigation water were tested (3.4 [S1], 7.1 [S2], 10.6 [S3], 14.1 [S4], and 17.7 dS m−1 [S5]), and deep ground water (1.3 dS m−1) was used as the control (CK). After 15 years of saline water irrigation, we monitored soil physicochemical properties and soil respiration. In addition, we developed a structural equation model of the relationship between them. The results demonstrated that saline water irrigation significantly reduced soil water-stable aggregate content and porosity by 4.42–45.33% and 6.52–14.10%, respectively, and attenuated soil cellulase, α-glucosidase, and alkaline phosphatase activity. Soil respiration under saline water irrigation was significantly reduced by 5.28–33.08%. Moreover, saline water irrigation with salinity below 10.6 dS m−1 had no significant effect on cotton yield. Moreover, soil salinity (62%), water-stable aggregate content (46%), and soil porosity (25%) had significant effects on soil respiration, and soil porosity had a significant positive effect on soil alkaline phosphatase activity according to the structural equation model. Overall, saline irrigation with salinity below 10.6 dS m−1 can alleviate water shortages and reduce soil carbon emissions without affecting cotton yield in the study area.