Irrigation Water Salinity Research Articles

Using Bacillus megaterium as a bio-fertilizer alleviates salt stress, improves phosphorus nutrition, and increases cauliflower yield

The traditional crop production system involves the use of large amounts of chemical fertilizers, which negatively impacts the ecological environment by increasing soil degradation and salinity, threatening sustainable agricultural production. Therefore, there is an urgent need for agricultural practices that increase plant productivity and reduce negative impacts on the environment. Phosphate-solubilizing microorganisms can enhance nutrient availability and plant uptake. This study investigated the effect of Bacillus megaterium as a bio-fertilizer (inoculated and non-inoculated) combined with phosphorus fertilizer (40, 60, and 80 kg. ha−1) on the growth and yield of cauliflower grown under saline conditions, saline soil (9.68 dS.m−1) and saline irrigation water (7.12 dS.m−1). Salt-stressed cauliflower inoculated with Bacillus and fertilized with 60 or 80 kg. ha−1 P2O5 showed improved growth and higher yield compared to other treatments, without significant differences between them. However, Bacillus-treated plants fertilized with 60 P2O5 showed increases in superoxide dismutase (SOD) by 29.3%, catalase (CAT) by 13.9, chlorophyll by 10.4%, N by 7.8%, and P by 8.6%, while Na decreased by 7.8%, resulting in significant increases in cauliflower yield (head weight by 9.3%, and total yield by 8.3%) compared with the control treatment (recommended P fertilizer, 80 kg P2O5. ha−1). The results indicated that the inoculation of salt-stressed plants with Bacillus megaterium is a promising and feasible approach to reduce phosphorus fertilizer use by up to 25% and enhance membrane stability (MSI), relative water content (RWC), nutrient availability, and growth performance, thus mitigating the adverse effects of salt stress exacerbated by climate change.

Responses of Tomato Crop and Water Productivity to Deficit Irrigation Strategies and Salinity Stress in Greenhouse

Saudi Arabia faces water scarcity and inadequate sustainable sources, particularly in agriculture, necessitating efficient irrigation water management to improve productivity amidst rising demand. The study investigated the impact of irrigation levels and water salinity on tomato plants in greenhouses, covering four irrigation levels (100%, 80%, 60%, and 40% of ETc) and three water sources (FW (0.9 dS·m−1), SW (3.6 dS·m−1) and MW (2.25 dS·m−1)). Salinity impacts crop yield, physiological responses, and fruit quality. The photosynthesis, stomatal conductance, transpiration, and chlorophyll content decrease with MW and SW, negatively affecting morphological characteristics. For MW, it was recommended to apply 60% deficit irrigation with a yield of 98 kg·ha−1, and water productivity (WP) improved to 21.93 kg·m−3 compared to 13.65 kg·m−3 at full irrigation (FI). In SW, 80% irrigation was suggested, as there was no significant difference in yield compared to FI. For FW, 60% deficit irrigation produced the best water conservation (104.58 kg·ha−1 yield and 23.19 kg·m−3 WP), while FI produced the highest yield per unit area (123.48 kg·ha−1 yield and 16.51 kg·m−3 WP). Nonetheless, greater water and salinity stress was associated with increased fruit quality measures such as total acidity, vitamin C, and soluble solids. The results show that implementing deficit irrigation with salinity strategies in greenhouse tomatoes could improve crop adaptability, yield, and water productivity in the face of water scarcity and salinity variability.

Morfofisiologia e trocas gasosas da romãzeira sob estresse salino e aplicação foliar de nitrogênio

ABSTRACT Salinity is one of the abiotic stresses that affect gas exchange and growth of pomegranate. In this context, the application of nitrogen fertilizer through the leaves can minimize these effects. Thus, the objective of present study was to evaluate the effect of foliar nitrogen fertilization on pomegranate seedlings irrigated with brackish water. The design used was randomized blocks, in an incomplete factorial scheme (Central Composite Design) with five electrical conductivities of irrigation water - ECw (0.50, 1.15, 2.75, 4.35, and 5.00 dS m-1) and five doses of foliar nitrogen fertilization - FNF (0, 0.33, 1.15, 1.97, and 2.30 g L-1), with four replicates and two plants per experimental plot. Plant height, number of leaves, stem diameter, and gas exchange (stomatal conductance, net photosynthesis, intercellular CO2 concentration, transpiration rate, instantaneous carboxylation efficiency, instantaneous water use efficiency, and intrinsic water use efficiency) were evaluated at 60 days after the beginning of irrigation with saline water. Salinity of irrigation water negatively affects the gas exchange of pomegranate seedlings. Foliar nitrogen fertilization up to 1.31 g L-1 improves plant height and number of leaves in pomegranate seedlings under salt stress. Foliar nitrogen fertilization up to 1.59 g L-1 increases the net photosynthesis of pomegranate seedlings.

Effect of sufficient and deficit irrigation with different salt inputs on the yield of cucumber

Soil salinisation is considered one of the major environmental hazards threatening agricultural productivity and can be accentuated by climate change as well as the use of low-quality water in irrigation. This is the case in our study area which is affected by secondary salinisation due to the use of saline irrigation water for horticultural production. Deficit irrigation technique is implemented especially in arid and semiarid regions due to its potential to optimise water productivity while maintaining or increasing crop yield. The main objective of this study was to compare the effect of irrigation with sufficient (SD) and deficit (DD) doses. This research was carried out in Karcag in 2020. Cucumber was grown on a meadow chernozem soil and was irrigated with SD and DD of two irrigation water qualities. Soil moisture was monitored and crop yields were recorded. Despite the differences in quality and quantity of water, the application of less water by DD maintained the same yield as SD. We found a non-significant difference between the average soil moisture contents under the treatments (15.5 v/v% for SD and 13.5 v/v% for DD). Deficit irrigation can be an efficient technique due to its potential for improving water use efficiency, maintaining sufficient soil moisture content favourable for proper crop development and yield.

Agronomic Analysis of the Replacement of Conventional Agricultural Water Supply by Desalinated Seawater as an Adaptive Strategy to Water Scarcity in South-Eastern Spain

Climate change is affecting water resources in south-eastern Spain, and this mainly affects irrigated agriculture. In this context, seawater desalination is an adaptive strategy that has provided increasing water allotments to agriculture for the last decade, to replace decreasing conventional resources. Farmers are concerned about the agronomic effects of this substitution and its economic consequences. This study focuses on the potential agronomic impacts of the progressive replacement of the irrigation water from the Tagus–Segura transfer (TST) with desalinated seawater (DSW) on the main crops of south-eastern Spain. To that end, five main agronomic concerns were selected and analyzed under three water supply scenarios using increasing rates of DSW (0, 50, and 100%). The results indicated that, in addition to other economic or environmental considerations, sufficiently relevant agronomic aspects exist that need to be considered when replacing the TST supply with DSW. This study evidences the risks of phytotoxicity and soil alkalinization, due to the increase in boron concentration and the imbalance between monovalent and divalent cations in the DSW, respectively, and also a slight increase in the cost of fertilizers. In addition, the irrigation water salinity effect on production and total irrigation requirements was negligible, as both water sources present sufficiently low salinity. The detrimental effects were mitigated under a partial replacement scenario, so the blended use of DSW with conventional resources seems the most recommendable option for its agricultural management, rather than irrigating with DSW alone.

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).

Life‐history parameters of the western flower thrips, Frankliniella occidentalis, are affected by host plant salinity stress

AbstractSalinization, as one of the foremost abiotic stresses, is an intensifying problem in many agroecosystems. Climatic changes, along with altering land use and also salinity of irrigation water all lead to enhanced soil salinity in agricultural lands. Changes in plant characteristics, as a result of raising soil salinity, may impose bottom‐up impact on plant‐feeding insects. We assessed the bottom‐up impact of salinity stress on demographic traits of the western flower thrips (WFT), Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), on cherry tomato, Solanum lycopersicum L. var. cerasiforme (Solanaceae) plants under greenhouse conditions (27 ± 2 °C, 65 ± 5% r.h., and L16:D8 photoperiod). Our results indicated that salinity stress interfered with the immature development period, adult longevity, and sex ratio of WFT. Salinity stress biased the sex ratio in favor of males. Significant concentration‐dependent differences were observed in the intrinsic (r) and finite (λ) increase rates and the net reproduction rate (R0) of WFT at different salinity levels. Salinity adversely influenced WFT development; nonetheless, population projection forecasted an ascending WFT population growth under moderate salinity stress of 100 mM (2.8 dS m−1 of NaCl), whereas severe salinity stress of 150 mM (4.7 dS m−1 of NaCl) resulted in remarkable fitness costs in WFT. This study demonstrates that WFT has the potential to become problematic in regions with moderate salinity. Therefore, it might exacerbate the detrimental impact of salinity on tomato production. The current survey provides information on the abundance of WFT on saline‐stressed tomato plants, thereby contributing to developing environmentally friendly measures to manage this notorious species in ecosystems under salinity stress.

Physiological, biochemical, and yield attributes of fennel, anise, and ajwain in response to saline irrigation water

Physiological, biochemical, and yield attributes of fennel, anise, and ajwain in response to saline irrigation water

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.

Effect of Irrigation Water Salinity Levels on Growth Indicators of Wheat (Triticum aestivum L.)

Effect of Irrigation Water Salinity Levels on Growth Indicators of Wheat (Triticum aestivum L.)

Early seedling features and mineral content of maize seeds grown under salinity stress

High seedling performance is crucial for the growth and development of plants, as it directly affects the potential for crop yield. Therefore, robust early seedling characteristics can lead to higher yields and better crop productivity. This work evaluated the early seedling characteristics of maize seeds grown under four irrigation water salinities (0.30, 1.5, 3.5, and 7 dS m-1). For this purpose, maize plants were grown to maturity in pots under rain shelter conditions, and then maize seeds were harvested. Subsequently, the maize seeds germinated to determine the early seedling characteristics, the leaf's Na+, Ca+2, K+ content, and the K+/ Na+, Ca+2/ Na+. The results showed that irrigation of maize crops at 7.0 dS m-1 reduced seedling fresh weight, root fresh weight, and SPAD parameters by 46.9%, 78.1%, and 38.7%, respectively, compared to 0.30 dS m-1. Irrigation of maize plants with 8.0 dS m-1 significantly hampered the reusability of maize seeds and decreased seedling height (7.81 cm), root dry weight (0.13 g), and root length (5.5 cm). Moreover, the highest ratios of K+/Na+ (12.58) and Ca+2/Na+ (3.46) ratios and the lowest leaf Na+ content (0.24%) of maize seedlings were found in 0.30 dS m-1 treatment. Based on the results, it could be suggested that the reusability of maize seeds, which irrigation maize crops with ≥ 3.5 dS m-1 saline water, is not recommended for sustainable maize production due to low seedling growth performance. Finally, the current study has the potential to provide important insights into identifying robust and healthy maize seeds grown in high-salinity environments.

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.

Improvement of (Eruca sativa Mill) yield, oil, chemical constituents and antioxidant activity utilizing a by-product of yeast production (CMS) with zinc and boron under salinity stress conditions

The impact of low-quality irrigation water on plant development has garnered significant attention from researchers. In light of this, two field experiments were conducted to evaluate the performance, yield, oil production and composition, as well as active constituents of Rocket (Eruca sativa Mill) cultivated in calcareous soil under saline water irrigation. Foliar sprays containing condensed molasses soluble (CMS), zinc (Zn), and boron (B) alone or in combination were used for irrigation. The data obtained from measuring various parameters of Rocket following foliar spraying with CMS, Zn, B or their combinations demonstrated that most treatments resulted in a significant increase in these parameters. The highest values for most measurements were observed when foliar application included all three components (CMS ​+ ​Zn ​+ ​B), resulting in a seed yield of 184.6 ​g/m2 and an oil content of 675.3 ​kg/ha. Compared to the control group, the macronutrient content of N, P, K, Mg, and Ca increased by 34.4%, 56%, 42%, 45%, and 39% respectively in the seeds treated with these components. Furthermore, carbohydrates, proteins, phenolics flavonoids, and antioxidants showed increases of 24%, 34%, 21%, 43%, and 28% respectively compared to the control group. Gas-liquid chromatography analysis identified ten components present in the seed oil characterized by higher unsaturated fatty acids ranging from 81.28% to 92.28% and lower saturated fatty acids ranging from 6.72% to 8.21%. Therefore, foliar spray application including CMS, zinc, and boron can help alleviate salinity effects on Rocket plants grown under saline water irrigation conditions while improving growth, yield, oil production, and nutritional content such as total carbohydrates, proteins, and macronutrients levels.

Potassium-phosphorus fertilization to reduce salt stress in West Indian cherry

West Indian cherry stands out in the Brazilian fruit scenario due to the nutritional quality of its fruits, making it a promising crop in the generation of employment and income. However, the occurrence of water sources with high concentrations of salts is a limiting factor for the expansion of crop area. In this context, the objective was to evaluate the production and post-harvest quality of West Indian cherry cv. BRS 366 Jaburu under prolonged saline stress and potassium-phosphorus fertilization combinations in the second year of cultivation. The experiment was carried out in 250 L lysimeters in a greenhouse in the municipality of Campina Grande-PB, Brazil. Treatments were distributed in randomized blocks in a 5 × 4 factorial scheme, with five levels of electrical conductivity of irrigation water - ECw (0.6, 1.4, 2.2, 3.0, and 3.8 dS m−1) and four combinations of potassium-phosphorus fertilization (100/100, 85/85, 60/60, and 45/45% of K2O/P2O5 recommendation for the second year of cultivation) with three replicates. Irrigation water salinity of up to 3.8 dS m−1 does not compromise the post-harvest quality of West Indian cherry. The increase in water salinity reduces mean fruit weight and water consumption of plants, while waters with electrical conductivities of 3.0 and 2.0 dS m−1 promote the maximum values of total soluble solids and ascorbic acid in the fruits, respectively. The supply of 45/45% K2O/P2O5 of the fertilization recommendation provides the higher content of ascorbic acid in West Indian cherry fruits and, when associated with ECw of 1.4 dS m−1, promotes the higher production of the crop.

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.

Biofertilizer application improved cotton growth, nitrogen use efficiency, and yield in saline water drip-irrigated cotton fields in Xinjiang, China

Saline water irrigation presents a potential solution for addressing freshwater shortages. However, this practice can result in salinity stress for cotton plants. Hence, it is imperative to explore measures that can alleviate salinity stress when implementing saline water irrigation. The aim of this study was to determine the effects of biofertilizer (F2) application on cotton growth, nitrogen use efficiency, yield, and fiber quality under different water: 0.48–1 g L−1 (W1, freshwater), 3 g L−1 (W2, brackish), and 7 g L−1 (W3, salt water) irrigation, compared to the use of chemical fertilizer (F1) alone. A two-year field experiment was conducted in 2021 and 2022 in film-mulched drip-irrigated cotton fields. The results showed that biofertilizers significantly enhance photosynthesis and N utilization efficiency under both W1 and W2 irrigation, compared to treatments where chemical fertilizers were applied alone. At the same time, the cotton total biomass, and cotton fiber elongation were significantly increased, and the cotton seed yield was significantly increased by 6.15–10.56 % (W1) and 6.49–11.81 % (W2) in two years. The application of biofertilizers indirectly increases cotton yield by enhancing cotton biomass and improving N utilization. In conclusion, the application of biofertilizer can effectively alleviate the salinity stress on plants in both W1 and W2 irrigation situations. Future research on saline water irrigation should take into account the long-term effects of using biofertilizers in saline irrigation situations.

Photochemical efficiency and growth of sugar apple under irrigation with saline water and foliar nitrogen

Salt stress has compromised the worldwide expansion of fruit farming by causing damage to light energy regulation and crop growth, which can be mitigated by applying foliar nitrogen (N). From this perspective, this study aimed to evaluate the chlorophyll contents, fluorescence, and the growth of sugar apple seedlings under irrigation with saline water and foliar N fertilisation. The experiment was conducted in a plant nursery and following a randomized block design referring to five electrical conductivity levels of irrigation water (0.5, 1.15, 2.75, 4.35, and 5.0 dS m-1) and five foliar N levels (0.0, 0.33, 1.15, 1.97, and 2.3 g L-1), with four replications and two plants per plot, totaling nine combinations generated by the Box central composite design. Irrigation water salinity reduces the growth of sugar apple seedlings irrigated with conductivity levels over 1.7 dS m-1 at 90 days after emergence. Foliar N fertilisation increased the photochemical efficiency and growth of sugar apple seedlings. The foliar application of 1.93 g L-1 mitigate the deleterious effects of water salinity on the photochemical efficiency and growth of sugar apple seedlings.

Contribution of Arbuscular Mycorrhizal Fungi (AMF) in Improving the Growth and Yield Performances of Flax (Linum usitatissimum L.) to Salinity Stress

Throughout the world, salinity is a major environmental issue that limits agricultural productivity, particularly in arid and semi-arid regions. In addition, climate change is the most important reason for the salinization of agricultural soils in the world, so it is now essential to find solutions to increase salinity tolerance in plants. This study investigated the potential of arbuscular mycorrhizal fungi (AMF) inoculation to enhance the growth and yield performances of flax under different salinity levels by conducting a pot experiment. The experiment was laid out in a two-factor completely randomized design including AMF inoculation (AMF+: with inoculation; AMF−: without inoculation) and irrigation water salinity (0, 50, 100, and 150 mM NaCl). According to the results, it is evident that salt stress caused negative physiological effects, including limited growth, reduced photosynthesis, and decreased nitrogen (N) and phosphorus (P) content in the shoots and roots of flax plants. Moreover, mycorrhizal association improved the salt tolerance of the plants by increasing chlorophyll content, and enhancing N and P shoot and root contents and consequently yield parameters, such as seed and stem fiber yield, particularly at moderate salt concentrations (50 and 100 mM NaCl). In particular, under 100 mM, AMF increased the total chlorophyll content, N shoot and root content, P shoot and root content, and seed and stem fiber yield by 30.4%, 36.1%, 31.0%, 38.9%, 45.4%, 35.2%, and 26.9%, respectively. As a result of using AMF, flax plants grown under salt stress exhibited tolerance, suggesting that AMF could be applied in saline environments to maintain ecological stability.