جستجوی مقالات مرتبط با کلیدواژه « تنش شوری » در نشریات گروه « آب و خاک »

Using simulation models is a key strategy in agricultural water management and an effective way to predict the impact of irrigation management and water quality on crop yield. This study aimed to evaluate the performance of the SWAP and AquaCrop models in simulating the growth and biomass production of three maize varieties under the conditions of using saline water for irrigation with a drip irrigation system at the research farm of Tehran University of Agriculture and Natural Resources Campus. In order to calibrate and validate the models, field data obtained from a factorial experiment with two factors of maize variety (SC704, 400, and 260) and irrigation water salinity (0.7, 3, and 5 dS/m) were used. In the validation stage of the AquaCrop model, the R2, RMSE, and NRMSE statistics for the canopy cover (CC) showed a high level of agreement between the measured and simulated data, with values of 0.953, 5.69, and 8% respectively. For the SWAP model, the calculated statistics for the leaf area index (LAI) were 0.477, 1.610, and 54.2%, respectively. Despite the poor performance of the SWAP model in estimating LAI, both the SWAP and AquaCrop models effectively simulated the biomass of maize cultivars under different treatments. In the calibration and validation stage, RMSE and NRMSE of both models were less than 0.5 ton/ha, with 3% (calibration) and 1 ton/ha, 7% (validation), respectively. In general, both models can be used in various studies for different maize cultivars under irrigation water and soil salinity conditions.

In the south of Iran, due to being located in the arid and semi-arid regions, the agricultural sector faces soil salinity resulting from the capillary rise of salt from the shallow saline water table to the soil surface and reducing crop yield. The objective of this research was to investigate the effect of surface drip irrigation (DI) and subsurface irrigation (SDI) methods on soil profile moisture and salinity distribution, maize (SC 703) yield, and irrigation water use efficiency in the presence of shallow saline water table (60 and 100 cm), during summer and spring seasons of 2021. A factorial experiment was conducted based on randomized complete block design with three replications in drained lysimeters filled with loamy soil (specific gravity 1.45 g cm-3) in field conditions. The results showed that the accumulation of salt above the dripper in subsurface irrigation method at both SDI100 and SDI60 treatments, was significantly more than the surface irrigation method (p<0.01). The results also revealed that summer maize yield was more than spring maize yield. Furthermore, in the summer season, irrigation in the root development zone in the SDI100 and SDI60 treatments caused an increase in the maize yield by 25 and 61%, respectively, and Water Productivity Index (WP) by 25 and 58%, respectively, in comparison to DI100 and DI60. Evaporation in SDI60 and SDI100 treatments was 26-30% and 43-51% lower than DI60 and DI100 treatments, respectively. The results of this research showed that SDI is more effective than DI in controlling soil profile salinity and plant yield.

Soil salinity, especially in arid and semi-arid regions, is one of the factors that limit the growth of plants. Excessive accumulation of sodium and chloride ions leads to reduced growth and imbalance of nutrients. The use of exogenous polyamines, including putrescine, spermidine and spermine, is considered as an effective method not only in determining their role in response to salinity, but also as a way to increase plant resistance to salinity. Camelina is an oilseed product of the Brassica family, which contains other bioactive compounds such as flavonoids and phenolic products and as a new source of essential fatty acids, especially omega-3 fatty acids. This study was conducted with the aim of evaluating the effect of different levels of sodium chloride and foliar spraying of spermine, spermidine and putrescine on seed yield and the concentration of leaf and root nutrients in Camelina plant. The experiment was carried out in March 2022 as factorial design based on a completely random design (CRD) in the form of pot culture with 12 treatments and 3 replications. The salinity stress treatment was with Urmia lake water at three levels (0, 15, 30 ds/m). Foliar treatment at 4 levels 1- Foliar spraying with spermine (2 mM), 2- Foliar spraying with spermidine (2 mM), 3- Foliar spraying with putrescine (2 mM) and control (no foliar spraying). The application time of foliar spraying was done every 3 days (totally in 6 stages) after establishing three seedlings in the pot and reaching the four-leaf stage. At the end of the Camelina plant growth season, to calculate the seed yield, the seeds in the capsules of three plants in each pot were separated and weighed. Statistical analysis of data was done using SAS software (version 9.1) and MATATC, and comparison of means was also done by Tukey's test at the five percent level. Excel program was also used to draw graphs. The results of this research showed that the salt stress was 30 and 15 ds/m compared to the treatment without salt decreased leaf potassium (52 and 17%), root potassium (44 and 37%), leaf magnesium (50 and 28%), root magnesium (56 and 24%), leaf zinc (58 and 47%), root zinc (39 and 29%), leaf iron (10 and 2%), root iron (57 and 23%) and seed yield (52 and 10%), but it increased the amount of leaf sodium (89 and 82%), root sodium (39 and 11%), leaf calcium (14 and 6%) and root calcium (76 and 28%), respectively. Also, salinity stress caused a decrease in the ratio of potassium to sodium absorption, but increased the ratio of calcium to the sum of sodium and potassium in the roots and leaves due to the increase in the amount of sodium and the decrease in potassium. At all salinity levels, foliar spraying with polyamines increased leaf and root potassium, leaf and root magnesium, leaf and root zinc, leaf and root iron, by reducing the amount of sodium in leaves and roots. Also, foliar spraying with spermine, spermidine and putrescine compared to no foliar spraying, increased the seed yield by 32, 8 and 21%, respectively. The results of this research showed that foliar spraying with spermine, spermidine and putrescine by improving the absorption of macro and micro elements in roots and leaves, increasing the ratio of potassium to sodium and the ratio of calcium to total sodium and potassium in roots and leaves could moderate the effects of salinity stress and improve the seed yield of camellia under salinity stress conditions and it prevented excessive reduction in seed yield.

Salinity is a serious problem and one of the main factors in reducing agricultural productivity worldwide. The use of microorganisms to improve plant growth in low quality soil is a potential solution to address this problem. The salinity resistant microbiome improves the health of the salinity affected soils, maintains ecological functions and enhances plant growth. Salt tolerant plant growth promoting rhizobacteria (ST-PGPR) are able to adjust the salinity stress adverse conditions for their symbiotic plants through several mechanisms. This study aimed to isolation, identification and investigation the characteristics of salt tolerant-plant growth promoting rhizobacteria from the rhizosphere of halophyte plants.

Salinity tolerant plant growth promoting bacteria were isolated from the rhizosphere of native halophyte plants collected from the north of Iran. Bacterial isolates were selected according to their ability to growth in 2 M sodium chloride and traits of the motility, inorganic phosphate solubilization ability in PKV-Agar medium using phosphate solubilization index calculation, and siderophore production capacity in CAS-agar medium by calculating of its production index. Then, the top 10 isolates were selected and the ability of nitrogen fixation in Burk's medium, potassium dissolution in Aleksandrov's medium by using potassium solubilization index, as well as, the production of intrinsic IAA and the tryptophan-dependent IAA were investigated. Finally, molecular identification of selected bacterial isolates was performed based on 16S rDNA gene sequencing.

Four genera of Bacillus, Klebsiella, Proteus and Halomonas were identified after 16S rDNA gene sequencing. All isolates were motile. The most of isolates belonged to the genus Bacillus. Species belonging to Klebsiella and Halomonas genera had the highest salt tolerance. Klebsiella genus showed phosphorus and potassium solubilizing ability more than other isolates. The highest amount of siderophore production was observed in the isolate belonging to Proteus genus. All isolates were able to fix nitrogen. Among the studied isolates, Bacillus isolates had the highest rate of intrinsic IAA, and the tryptophan-dependent IAA production in B. licheniformis was higher than other isolates.

Isolation of wide range of salt-tolerant bacteria with favorable characteristics from the rhizosphere of halophyte plants indicates the microbial richness potential of this area, which provides the possibility of finding useful microorganisms that promote plant growth and reduce the adverse effects of stress in plants. Keywords: Plant growth promoting bacteria, Salinity stress, Halophyte plants, Indole acetic acid

Salinity is the main problem of the fields under irrigation in many regions of the world which has been caused the farmers encountered with some questions such as determining of the optimum depth of irrigation water by using of saline water, reuse of drained water from the agricultural fields and yield reduction that resulting in reduction revenue by using of saline water. Water shortage and unsuitable quality of irrigation water are two main factors which has restricted the crop production in many regions of Iran. Among environmental stresses, salinity stress is the main factor of crop reduction. Many physiological processes of plants such as germination, seedling growth, flowering and fruit ripening are decrease by increasing in salt concentration in soil and irrigation water. Deficit irrigation and soil or irrigation water salinity decrease the matric and osmotic potential in soil water content respectively, which are resulting in reduction of water absorption by plant roots. Camelina (Camelina sativa L. Crantz) is a plant with oil seed from Brassicaceae family that interest to its planting has increased in recent years. The causes of that are high tolerance of this plant to unfavorable environmental conditions and usage possible of it for many purposes. Appropriate usage of yield- salinity- water crop production functions can be improved agricultural water consumption management in regions with scarce of water resources. Crop production functions such as linear form, Cobb-Douglas, quadratic and transcendental function models were used to simulate relative grain yield of camelina. As the area study in this research namely Kashmar plain, has been forbidden for withdraw of groundwater and many agricultural deep wells in this area have high salinity water, in order to optimum management water consumption in agriculture, determining of the best water-salinity-yield production function for crops such as oil seed plants (canola, seasame and camelina) are essential. For the first time, camelina was planted in Kashmar natural resource and agricultural research center as pilot plan in 2021. As the compounded effects of salinity and water stress on camelina grain yield has been not investigated in this area, the objective of this research was to obtain the optimum crop production function as affected by drought stress and irrigation with saline water. A greenhouse experiment was conducted as a factorial in the form of a completely randomized design with three replications. The experiment treatments were four levels of salinity including drinking water S1=0.7, S2=4, S3=8 and S4= 12 dS m-1 and three levels of irrigation water including W1 (100% provided crop water requirement), W2=0.75W1 and W3=0.5W1 applied in a loamy sand soil texture with bulk density of 1.41 gr cm-3. Linear, Cobb-Douglas, quadratic and transcendental function models were used to simulate relative grain yield of camelina. In order to determine of optimum crop water production function, statistical analysis was done on obtained data and by determining of related statistics the role of each input was characterized quantitatively. For assessing of validation, the obtained functions, the statistics including maximum error (ME), root mean square error (RMSE), determining coefficient (R2), efficiency function (EF) and coefficient of residual mass (CRM) were used. The results showed that quadratic function model was the most appropriate model for estimating of grain yield of camelina under pot planting conditions in greenhouse. Marginal product (MP) and marginal rate of technical substitution (MRTS) indices of grain yield related to quality and quantity of irrigation water showed that with increase a centimeter of irrigation water depth (hypothesized salinity is constant), camelina grain yield increased 56.8 kg ha-1. Also, MP related to irrigation water salinity indicated that with increase a unit of salinity (hypothesized irrigation water depth is constant) camelina grain yield decreased 38.7 kg ha-1. According to findings of this research it could be said that 70 mm depth of irrigation water and EC less than 4 dS m-1 is suitable for achievement to optimum grain yield of camelina under pot planting conditions in greenhouse. It is noteworthy that further consumption of water by plant (almost 300 mm) and longer of growth period duration of plant in field compared to pot planting conditions in greenhouse caused to production function coefficients recommended in this study would not be applicable in field conditions and it is necessary that supplemental studies would be conducted for determining of optimum yield- salinity- water production functions of camelina under field conditions.

From the economic and medicinal point of view, Aloe vera is a herbaceous and perennial plant that has attracted the attention of many farmers Iran. Climatic conditions throughout the year and the quantity and quality of irrigation water affect Aloe vera yield. For this reason, the research was conducted with the aim of investigating the effect of aforementioned factors on the Aloe vera yield and yield components. To achieve this goal, a strip-block design was carried with two factors, include: amount of irrigation water at three levels (I1: 50, I2: 75 and I3: 100% of irrigation water requirement) and irrigation water salinity at two levels (S1: 5 and S2: 10 dS.m-1) with three replications, in a research farm in Omidiye with longitude 30°37° and latitude 49°49°. The first harvest was done in the fall of 2019 and the second harvest in the spring of 2020. The results showed that in the first harvest, irrigation had a significant effects on leaf width, leaf fresh weight (P-value≤0.05), gel weight, the ratio of gel weight to leaf weight, the number of leaves and the water use efficiency (P- value≤0.01). Salinity had a significant effects on leaf thickness (P-value≤0.05), leaf width, leaf fresh weight, gel weight, the ratio of gel weight to leaf weight and water use efficiency (P-value≤ 0.01). In the second harvest, irrigation had a significant effects on the ratio of gel weight to leaf weight, number of leaves and water use efficiency and salinity had a significant effects on leaf width, leaf thickness, leaf fresh weight, gel weight , the ratio of gel weight to leaf weight and water use efficiency . In both the first and second harvests, the interaction effect of irrigation water and salinity only showed a significant effect on the water use efficiency (P-value ≤ 0.05).

In the situation where Iran is severely suffering from the lack of freshwater resources and the water resources crisis is a serious issue, paying attention to non-conventional water sources is an unavoidable necessity, in which case environmental tensions will occur. Especially salinity becomes important. To investigate the effects of salinity stress in German chamomile with the use of different culture media, factorial research was carried out in the form of a completely randomized design with three replications. In this experiment, two factors of salinity stress (Sa) (0, 50, 100, and 150 mM) and different percentages of culture medium (perlite 100%, cocopit 25%+perlite 75%, cocopit 50%+perlite 50%, cocopit 75%+perlite 25%, and cocopit 100) %) was investigated. The investigated morphological and physiological traits included fresh and dry weight of root and shoot, stem diameter, amount of chlorophyll a and b and total chlorophyll. The results showed that all investigated traits were subjected to salinity stress and showed a significantly decrease compared to the control. The culture medium containing 75% cocopeat and 25% perlite increased the fresh weight of roots by 22.11% compared to the culture medium containing 25% cocopeat and 75% perlite. Also, the control treatment had a 96.08% increase in root fresh weight compared to salt stress with a concentration of 150 mM. Regarding the amount of total chlorophyll, the results showed that Co50Pe50+Sa0, and Co75Pe25+Sa0 treatments were the most (3.93 and 4.01 mg per gram of fresh tissue, respectively) and Co0Pe100+Sa150, Co25Pe75+Sa150, Co50Pe50+Sa150 treatments. Co100Pe0+Sa150 had the lowest (respectively 2.01, 2.02, 2.06, and 2.19 mg per gram of fresh tissue). In general, it can be said that the German chamomile plant in the culture medium containing 75% cocopeat + 25% perlite can withstand severe salt stress and have acceptable growth.

Drought and salinity stress are the most important limiting factors for plant growth. Selenium has been introduced as one of the useful elements against the destructive effects of stress. To the investigation of influence salinity and drought stress on water productivity and some characteristics of Mentha piperita L in the presence of selenium, an experiment on the split in time was performed in the Torbat-e Jam region, Iran in 2020, including two levels of cut (cut1 and cut2), three levels of irrigation (including full irrigation (100% of water requirement) = I1, I2=75% I1 and I3= 50% I1), three levels of Salinity (0, 50 and 100 mmol NaCl) and selenium factor in 2 levels (0 and 5 mg/l Na2SeO4). The result showed that fresh and dry weight, plant height, the number of leaves per plant, and the number of nodes decrease under salinity and drought stress. Generally fresh and dry weight, plant height, number of leaves per plant, number of nodes, Essential Oil percentage, and water productivity in the first cut was more than in the second cut. Also, foliar spraying of selenium (5 mgr/lit Na2SeO4) increased the above characteristics and also increased plant resistance against salinity and drought stress. The result showed with increasing salinity and drought stress respectively water productivity increased and decreased. the result showed that the percentage of essential oil increased by applying mild stresses in the form of deficit irrigation and then by applying intense stress, the percentage of essential oil decreased. Also result showed that the use of saline water in the conditions of drought stress caused intensification of reduction in fresh and dry weight, number of nodes and percentage of essential oil.

Considering the state of water resources in Iran, using unconventional water for irrigation is inevitable. Investigating the regional plants response to salinity is essential. an experiment was conducted on the research farm of the Agriculture Faculty, Lorestan University. Mini lysimeters (pots) with a diameter of 25 and a height of 30 cm were used. In this research, irrigation schedule was based on weighing method. The research was carried out using five quality treatments of irrigation water including S0: Water of the region (control treatment), S1: EC= 2 dS/m, S2: EC=4 dS/m, S3: EC=6 dS/m and S4: EC=8 dS/m. NaCl was used to make saline water. The growth period of Satureja hortensis was 100 days. The amount of accumulated potential and reference evapotranspiration were obtained 758.68 and 884.26 mm. The results showed that the effect of salinity stress on morphological characteristics such as plant height, stem diameter, as well as dry leaf weight and flowering branch, root and stem in Satureja hortensis was significant at the probability level of one percent. The morphological characteristics decreased as salinity stress increased. The yield of Satureja hortensis in S0, S1, S2, S3 and S4 treatments was 1732, 1598, 1412, 1328 and 1230 kg / ha, respectively. The essential oil content increased significantly as salinity stress increased. These values during different experimental treatments were obtained 1.08%, 1.2%, 1.5%, 1.58% and 1.8%, respectively.

The objective of this study was to investigate the effects of combined stresses of irrigation salinity and nitrogen fertilizer on the yield and yield components of millet plant. The field experiment was conducted as a split plot experiment in a randomized complete block design with three replications at the research farm, Faculty of Agriculture, Ilam University during growing season in 2022. Treatments included four levels of irrigation salinity including 0.63, 3, 5, and 8 dS/m (S1, S2, S3 and S4) as main plots and three nitrogen fertilizer levels including; 100, 75 and 50 % of fertilizer requirement (N1, N2 and N3) as subplots. The results showed that the effect of salinity stress was significant on leaf/stem ratio and panicle length at P<5% and for the rest of the yield components at P<1%. Also, the effect of different nitrogen treatments was significant on all components yield of millet, except leaf/stem ratio, panicle length and plant height. The interaction effect of salinity and nitrogen stress was significant on thousand seed weight, biomass weight, yield and harvest index at the at P<1% and had no significant on leaf/stem ratio, panicle length and plant height. The highest millet yield was 3.76 tons per hectare in S1N1 treatment and the lowest yield was 2.53 tons per hectare in S4N1 treatment.

Water scarcity particularly in arid and semi-arid areas has been threatening food security for millions of people. Considering that Iran is located in an arid and semi-arid zone and crop production is not possible without irrigation management. In areas where crops are irrigated management and proper planning are necessary for optimal use of water. Due to the quantitative and qualitative decline of groundwater resources, it is essential to optimize water use in agriculture. One of the methods to optimize water use in agriculture, especially in arid regions, is to use yield-water-salinity functions. Also, Selenium has been introduced as one of the useful elements against the destructive effects of salinity and water stresses. Peppermint with the scientific name Mentha piperita L is one of the medicinal and aromatic plants whose essential oil has many medicinal, food, cosmetic and health uses. Given that salinity stress and drought stresses are serious issues and problems in arid regions, in such conditions, it is very important to predict crop performance under drought and salinity conditions.Therefore, this study was performed for the prediction of Mentha piperita L yield and the determination of optimal production function under salinity and water stress conditions in a research greenhouse in the Torbat-e Jam region.One of the other innovations of this research is the investigation of the effect of selenium on these production functions and also on water productivity, with the assumption of increasing plant tolerance against salinity and drought stress.An experiment of the split in time was performed in a completely randomized block design with three replications including two levels of cut (cut1 and cut2), Salinity factor in 3 levels (0, 50, and 100 mmol NaCl, three levels of irrigation (including full irrigation (100% of water requirement) = I1, I2=75% I1 and I3= 50% I1), and selenium factor in 2 levels (0 and 5 mg/lit Na2SeO4).To properly establish the plants, the plants were irrigated every other day for two weeks after the transfer of the rhizomes, then as soon as the emergence of new leaves, the pots were treated with sodium selenate (Na2SeO4) in the form of foliar spraying with concentrations of 0 and 5 mg/l, foliar spraying was done three times every other day, and 24 hours after the last foliar spraying, plants under other treatments (salinity and drought stress) were placed. Salinity treatments were added to the pots from the lowest amount and higher concentrations were added gradually over several days. To determine water requirement was used Class A evaporation pan and water treatments were applied based on it. To calculate the water requirement, plant coefficients of peppermint were determined for the initial, development, and middle growth stages, respectively, 0.69, 1.03, and 1.27. 30 days after the application of salinity stress and drought stress, the first cut was done, for a more detailed investigation, the second cut was done 45 days after the first cut.Yield data of Mentha piperita L (yield of two cuts gathered for better estimation together), once in the presence of selenium and once in the absence of selenium were fitted to different production functions including simple linear, Cobb-Douglas, quadratic, and transient models and the optimum one was determined after sensitivity analysis. The results showed that the coefficient of determination (R2) for estimation of the yield in the presence of selenium by quadratic, transcendental, simple linear, and Cobb-Douglas functions were 0.986, 0.981, 0.946, and 0.897, respectively. In the absence of selenium these coefficient were 0.998, 0.995, 0,959 and 0/871, respectively. According to the results of this research, the quadratic production function is recommended as the optimal production function for the yield of Mentha piperita L in the presence and absence of selenium in the Torbat-e Jam region. Therefore, to optimize the agricultural water consumption for the peppermint plant, it is suggested to use the quadratic production function in this region. Also, the results of the statistical parameters show a higher accuracy of the fitted function in the absence of selenium than in the presence of selenium.Also, the results showed water productivity in the presence of selenium was 17.81% higher than its value in the absence of selenium. It can be concluded that Selenium increases water productivity.

Biochar as an efficient strategy for the improvement of soil properties and organic waste management may reduce the potential effects of abiotic stresses and increase soil fertility. However, the effects of this organic amendment on soil microbial indicators under combined salinity and pollution have not been studied yet. Therefore, the objective of this study was to evaluate the influence of sugarcane bagasse biochar on some soil bioindicators in a Cd-polluted soil under saline and non-saline conditions. A factorial experiment was carried out with two factors, including NaCl salinity (control, 20 and 40 mM NaCl) and sugarcane bagasse biochar (soils unamended with biochar, amended with uncharred bagasse, 400 oC biochar, and 600 oC) at 1% (w/w) using a completely randomized design. Results showed that salinity increased the mobility of Cd (12-17%), and subsequently augmented its toxicity to soil microorganisms as indicated by significant decreases in the <a href="javascript:void(0)">abundance and activities of the soil microbial community. Conversely, sugarcane bagasse biochar application reduced the concentration of soil available Cd (14-18%), increased the contents of soil organic carbon (89-127%), and dissolved organic carbon (4-70%), and consequently alleviated the effect of both abiotic stresses on soil microbial community and enzyme activity. In conclusion, this experiment demonstrated that the application of sugarcane bagasse biochar could reduce the salinity-induced increases in available Cd and mitigate the interaction between salinity and Cd pollution on the measured soil bioindicators.

Salinity is one of the most important abiotic stresses that has many negative effects on plant growth. To investigate the effect of salinity water irrigation stress on morphological and physiological characteristics of sorghum, an experiment was conducted in a randomized complete block design with 3 replications in soil columns located in the Agricultural and Natural Resources Research Center of Mazandaran Province. The number of experimental columns was 15 and the duration of the experiment was 56 days. Salinity treatments included well water (control) (S1=0.995 dSm-1), Mix seawater and well water in proportions 1/4 (S2=4.680 dSm-1), 2/4 (S3=8.130 dSm-1), 3/4 (S4=13.710 dSm-1) and seawater (S5=15.910 dSm-1). In this study, dry and wet weight of shoots, seeds and roots, diameter and height of main stem, leaf area index, leaf area, harvest index, biological yield and resistance indices of sorghum were measured. The results of analysis of variance showed that the effect of salinity on all measured traits was significant. Increasing the salinity level of irrigation water from control (S1) to treatment (S5) caused a significant decrease at the rate of 1 to 70% in all measured traits except harvest index and root to stem ratio. Also the results of this study showed that the best salinity level to achieve maximum yield in sorghum (Equivalent to 13/218 g) is salinity level (S1). Regarding resistance indices, S1 treatment had higher k/Na and Ca/Na ratios than other treatments, which were 6.67 and 1.4, respectively. Also, the results of comparing the mean of traits between different treatments showed that there were no significant differences between S3 and S4 treatments in traits such as grain yield, straw yield, plant height, leaf area, harvest index, dry weight of root and resistance indices that Up to 3: 1 ratio, seawater to well water can be used to grow sorghum. Also, the relative yield of sorghum to salinity did not decrease by about 3.65 dS /m, which was considered as the tolerance threshold of this plant. But after increasing the salinity of soil saturated extract, plant yield decreased and at salinity of about 15 dS /m was halved. The slope of the sorghum yield reduction line at this stage was calculated to be 3% dS / m.

In this study, salinity tolerance of five sorghum varieties (Speedfeed, Kimia, Payam, Sepideh, and Pegah) was studied using five irrigation water salinity levels (non-saline water, 4, 8, 12 and 16 dS/m) in the greenhouse. The statistical design was a factorial randomized complete block design with 25 treatments and four replications. The studied traits included plant height, leaf area, dry weight of roots and shoots, ratio of dry weight of roots to shoots, leaf chlorophyll index, concentration of sodium, chlorine and potassium in leaves and roots. The effect of variety and the effect of salinity stress on the mean of all measured traits were significant (P <0.01). At salinities of 4, 8, 12, and 16 dS/m, shoot dry weight was lower than the control (5.72 g/plant) by16.2%, 35.1%, 55.7%, and 69.4%, weight of dried roots lost 26.6%, 53%, 72% and 82%, compared to the control (5 g/plant), and the leaf area of the plants decreased by 29.4%, 58.3%, 75.5%, and 86.3% compared to the control, respectively. There was a negative correlation between chlorine and leaf sodium concentrations with shoot dry weight. Fisher stress sensitivity coefficient was used to evaluate the salinity sensitivity of cultivars based on shoot dry weight. Based on this coefficient, Speedfeed variety had the lowest salinity sensitivity coefficient (0.73) and Pegah cultivar had the highest (1.21). Regression was determined between different salinity levels with shoot dry weight for each cultivar. Accordingly, Speedfed, Kimia, Payam, Sepideh, and Pegah cultivars suffered a 50% reduction in shoot dry weight in salinities of 13.89, 12.95, 9.73, 9.62 and 9.50 dS/m. Based on the results, Speedfeed variety had a higher salinity tolerance than other cultivars and is recommended for cultivation in saline soil and water conditions.

This research was conducted on lentil at Imam Khomeini international university in 2021. The treatments were included of rainfed (D) and five salinity levels of irrigation water with EC of 0.5 (S0), 2 (S1), 4 (S2), 6 (S3) and 8 (S4) dS.m-1. The experiment was performed in a randomized complete block design with three replications. In treatments of D, S0, S1, S2, S3 and S4, some parameters were measured; the biomass yields equal to 2094.66, 3621.9, 3525.6, 2771.6, 1965.62 and 1120.6 kg.h-1, the grain yield equal to 399.25, 957.53, 932.07, 639.25, 279.33 and 46.82 kg.ha-1 and the straw yield equal to 1695.41, 2664.37, 2593.53, 2132.35, 1686.29 and 1073.78 kg.ha-1,  respectively. The results showed that the use of water up to S2 salinity level was recommended for lentil cultivation. But higher salinity levels were reduced the yield relative to rainfed conditions. At the water salinity threshold of 5.5, 5.3 and 5.6 dS.m-1, the amounts of biomass, grain and straw were equal to rainfed conditions. Due to salinity stress, the relative yield (compared to rainfed) of biomass, grain and straw were decreased with a slope of 0.166, 0.325 and 0.129, respectively. As a result, the grain yield was more sensitive than the straw yield in terms of water salinity. The reason was the effect of salinity stress on plants pollination and lack of grain filling. The amount of water use efficiency (for production of lentil dry biomass) was calculated in treatments of D, S0, S1, S2, S3 and S4 which were equal to 3.55, 1.32, 1.3, 1.23, 1.11 and 0.97 kg.m-3, respectively. In general, the results showed the application feasibility of saline water (in the range of crop tolerance) for irrigation to increase the lentil yield (compared to rainfed conditions). In these conditions, the saline water resources of the region can be exploited.

Water is the source of life and one of the important resources for the sustainable development of countries. Population growth and consequently the need for more agricultural commodities and food products and on the other hand, the limitation of water resources, have led human beings to the optimal use of available water resources and the use of low-quality water (Dehghan et al. 2015). To make more efficient use of limited water resources in the agricultural sector, new strategies such as the use of unconventional and saline water in irrigation operations should be considered (Mardani Nejad et al. 2017). Knowing how plants respond to different degrees of salinity of irrigation water, which is used in different stages of vegetative and reproductive growth, is necessary for proper and optimal management of the use of unconventional water resources in agriculture. Beans are one of the most important crops in terms of high protein content and use in the diet. This plant is one of the annual legumes and is sensitive to water salinity, which is cultivated for seed production (Salehi, 2015b). Bean is one of the plants sensitive to salinity and tolerates salinity up to 2 dS/m, but its yield reduction starts from 0.8 dS/m (Kamel et al. 2016).This experiment was carried out to compare the effects of saline water application in vegetative and reproductive growth stage for irrigation of Derakhshan red bean cultivar, which is suitable for Shahrekord climatic conditions. Experiments of this pot study in open space, were performed in factorial form in a completely randomized design, with three replications in pots with a diameter of 40 and a height of 70 cm in the research farm of Shahrekord University with UTM coordinates (Zone = 39), X = 482573 m and Y = 3579364 m and altitude of 2070 m above sea level. The first factor of the experiment was the use of saline water at the mentioned three levels for irrigation in the vegetative growth stage and the second factor was the use of the same salinity levels for irrigation of reproductive growth stage. The data collected included yield, yield components and water productivity.The results of analysis of variance showed that salinity stress in the vegetative and reproductive growth stage of bean plant significantly reduces yield, yield components, water uptake, water productivity and biological productivity index (α <0.01). Harvest index was not affected by salinity stress at vegetative growth stage, while the effect of salinity stress at reproductive growth stage on harvest index was significant (α <0.01). The highest value of water productivity was achieved in the control treatment with a rate of 0.67 kg/m3; the lowest value of 0.39 kg/m3 was observed in the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of salinity level, the mean effects of salinity in vegetative growth stage led to the productivity of 0.64 kg/m3 and in reproductive growth stage led to the productivity of 0.59 kg/m3. The results also showed that the highest yield (3349 kg/ha) was related to the control treatment and the lowest yield with rate of 1779 kg/ha was related to the treatment of applying 2 dS/m saline water in two stages of vegetative and reproductive growth. Regardless of the salinity level, the mean effects of salinity led to the production of 3067 and 2892 kg / ha grain yield in the vegetative and reproductive growth stage, respectively. The highest amount of water uptake was observed in the control treatment with the rate of 10 mm/day and the lowest amount of 9 mm/day without significant difference in the treatment with a salinity of 2 dS/m in the whole growth period and the treatment of 2 dS/m in the vegetative growth period And 1.5 dS/m was observed during reproductive growth.The results of this experiment, like the results of Ben Usher et al., 2006, showed that increasing salinity during the vegetative growth period of the plant reduces the storage content of plant organs, which affects the yield and its components at the end of the period. On the other hand, the application of salinity stress during reproductive growth period has a direct negative effect on yield and its indicators. These effects will be exacerbated when salinity stress is applied simultaneously during the vegetative and reproductive growth stages. The effects of salinity stress on grain yield and water productivity were more significant in the reproductive growth stage. The result is that in conditions of limited water quality, in order to achieve higher yield and optimal use of water, water with suitable quality should be used in the reproductive growth stage, and saline water could be used in the vegetative growth stage.

Due to the severe shortage of fresh water in arid and semi-arid regions, farmers are forced to use deficit-irrigation techniques along with salt water. In order to minimize salinity and water stresses impacts on the yield and yield components of spinach plant, separately and mutually, a pot experiment was performed from November 2, 2018 to January 18, 2019. The experiment was performed as factorial in the form of a completely randomized design with four replications including three irrigation levels (consisting complete irrigation 100% water requirement =W1, W2=75% W1, and W3=50% W1) and three salinity factors (drinking water S1=0.75, S2=4, S3=8 dS/m) in Kashmar's arid climate. The results showed that separate salinity and deficit irrigation stress had a significant effect on the plant traits including the wet weight of aerial part, leaf surface, plant height, stem height, root length, the dry weight of aerial part and the dry weight of the root, but the mutual effect of salinity and deficit irrigation on the mentioned traits was not significant. As salinity and deficit irrigation increased, the morphological properties of the plant decreased; for example, the maximum wet weight of the plant's aerial part was 147.15 grams in the plant related to W1S1 treatment and its minimum was 38.36 grams in the plant related to W3S3 treatment. The results of comparing the average of plant growth traits showed that there was no significant difference between the treatment of 100% water requirement with salinities of 0.75 and 4 dS/m, but in the salinity treatment control (0.75 dS/m) there was a significant difference between various levels of deficit irrigation. In regard to the above results, it can be said that spinach plant is more sensitive to water stress than salinity stress and applying water stress to the plant during the growing season should be avoided

The possibility of modification the saline lands by planting the salt-resistant crops, prevents the production of wastewater and drainage costs. In this study, the possibility of modifying saline soils by planting barley at different irrigation levels and soil salinity, was investigated. Salinity treatments included 6(S1), 9.5(S2) and 13(S3) (dS.m-1) and irrigation treatments included the amount of 100(I1), 75(I2) and 50(I3) percent based on the barley water requirement. This research was done as a factorial experiment in a completely randomized design with three replications. Due to increasing soil salinity (from S1 to S3) at irrigation levels of I1, I2 and I3, the amount of evapotranspiration was reduced to 25.5, 30.6 and 36 percent, respectively. The amount of reduced soil salinity in S1, S2 and S3 treatments were equal to 4.34, 6.88 and 9.42 (in I1 treatment), 3.76, 4.92 and 6.08 (in I2 treatment) and 3.64, 3.58 and 3.52 dS.m-1 (in I3 treatment), respectively. Low irrigation reduced the soil modification efficiency. Also, increasing the soil salinity in low irrigation treatments had a high effect on this work. Due to drought stress, the amount of soil modification efficiency decreased to 16% (in S1 treatment), 48% (in S2 treatment) and 62.6% (in S3 treatment). However, at full irrigation level, increasing the soil salinity (up to S3 treatment) did not had effect on the soil modification efficiency. Regression functions were used to estimate the final soil salinity, by the initial soil salinity and irrigation level. The exponential model had the best fit between the two variables of EC_f/EC_i and I_i/I_1 . The overall result showed that achieving to the highest soil modification efficiency and optimal modeling, required to the full irrigation of the crop.

The aim of this study was to evaluate the effects of salinity of irrigation water in interaction with different levels of irrigation water and nitrogen requirements on growth characteristics and water use efficiency of spinach. A combination of five salinity levels (1, 4, 7, 9 and 11 dS/m) with three levels of water requirement including (75, 100 and 125% of irrigation water requirement) and four levels of nitrogen from the source of urea with a purity of 46% (0, 100, 150 and 200 mg/kg soil) under controlled greenhouse conditions in three repetitions were considered as the studied factors. The results showed that salinity in combination with water stress and nitrogen deficiency caused a significant reduction in plant growth. Yield in treatments 75 and 125% of water requirement was 22.7 and 10.8% less than 100% of water requirement, respectively. Salinity in the treatment of 75 and 100% water requirement had a significant effect on leaf area index; such that the treatment of 75% of water requirement with the salinity level 11 ds/m decreased the leaf area index 46% tward control treatment. By increasing the application of fertilizer at the optimal level of 150 mg N/kg soil, plant growth and yield for all salinity levels showed a significant increase. Water use efficiency increased in W1, W2 and W3 treatments at salinity levels 4, 7 and 4-7 ds/m, then decreased significantly with increasing salinity for all treatments of water requirement and nitrogen levels. Also, 125% treatment caused a further reduction in water use efficiency compared to 75% and 100% water requirement treatments for all salinity levels. Finally, the best treatment in terms of water use efficiency was observed in the treatment of 75% of water requirement at moderate salinity levels (4- 7 dS/m).

Salinity is one of the major constraints prevailing in the environment that affects not only plant growth but also agriculture productivity and soil fertility. Salinity stress causes nutritional and hormonal imbalance, ion toxicity, oxidative and osmotic stress and increase susceptibility of plant to diseases. In this regard, research has shown that salicylic acid causes resistance in plants to environmental stresses, including salinity. Nitrogen also has a direct effect on plant yield due to its significant role in plant establishment and photosynthetic and physiological abilities.

In order to investigate the effects of salicylic acid and nitrogen fertilizer application rates at different salinity levels on growth of wheat cv. Morvarid, an experiment was conducted as a split plot factorial based on a randomized complete block design with four replications in the fields of Mazraeh-E-Nemooneh located in Anbarolum, Aq Qala city, Golestan province. The main factor included three soil salinity levels (3-4 below wheat tolerance threshold (control), 9-11and 13-15 dS/m) and sub factors included two levels of salicylic acid (0 and 1.5 mM) and three levels of nitrogen fertilizer (urea) included 30% N less than soil test recommendation, N based on soil test recommendation and 30% N more than soil test recommendation, respectively. Salicylic acid was foliar applied twice at 2 weeks intervals in the tillering stage. Nitrogen treatments were applied in three stages- before planting and twice as top dressing at the tillering and stem elongation stages. Plant dry weight and height, grain yield, number of spike, number of grains per spike, thousand seed weight and spike length were measured.

The results showed that the effect of different levels of salinity on yield and its components were significant. With increasing the salinity, yield and yield components decreased (p≤0.01). However, yield and yield components increased as N fertilizer consumption increased (p≤0.01). So that the highest grain yield was in the +30% of soil test recommendation treatment (N3), which was significantly different from the other levels. Application of calicylic acid increased all parameters of yield and its components except for number of grains per spike and spike length (p≤0.01). The interactive effect of salinity and nitrogen showed that application of N fertilizer more than the soil test recommendation level up to moderate salinity level (9-11 dS/m) was increased yield and yield components but at high salinity level (13-15 dS/m) reduced these traits. Also, nitrogen application with salicylic acid improved these traits under low and moderate saline conditions, but could not have a significant effect on them at high salinity level.

Therefore, the application of salicylic acid and nitrogen fertilizer management to some extent alleviated the adverse effects of salinity up to moderate salinity levels and improved plant growth and yield by increasing plant tolerance to salinity. At high salinity condition, it is better to reduce the use of nitrogen fertilizer.