جستجوی مقالات مرتبط با کلیدواژه "آب های شور" در نشریات گروه "آب و خاک"

With the development of localized irrigation in arid and semi-arid areas, the soil is more susceptible to salinization. The salt accumulation in the soil can reduce crop yields, destruction of plants and even resulting the soil uncultivable. In this research, flood leaching and trickle leaching methods (tape) were investigated in a pistachio orchard. Comparing with the flood method, the results showed that, the amount of leaching water used in the trickle method was reduced by 62.7% for the first leaching leading to a total reduction of 26.7%. In the flood leaching method, the entire surface of the farm is leached, while in the 6-row method water to be directly use in saline accumulation areas, which saves leaching water. Also, in the trickle and flood methods the uniformity coefficient of salinity distribution increased by 7% and 3% respectively. In the trickle method, the salt mass balance added due to irrigation can be removed with only one washing step, while in the flood method, the mass of leached salt is less than the mass of added salt. For orchards leaching with localized irrigation, it is recommended to apply more leaching water to salts accumulation areas and for improving the salts management effectiveness low-leaching rates applied alternately is recommended.

To evaluate the effect of calcium nitrate on some growth characteristics of selected pomegranate (Punica granatum) genotypes, a factorial experiment was carried out based on randomized complete block design (BCRD) with 3 replications at Chahafzal Station of the National Salinity Research Center of Iran, in 2019-2020. Two factors were studied: genotypes at 6 levels (Post-Siyah Ardakan, Rabab Neyriz, Chah Afzal, Narak Lasjerd Semnad ,Vahshi Babolsar, and Malas Yazdi) and calcium nitrate at 3 levels (0 (control), 50 and 100 kg/ha), using irrigation water salinity of 9±0.5 dS/m.  The results showed that type of genotype and levels of calcium nitrate affected morphological and physiological characteristics and concentration of nutrient elements in leaves. The highest and lowest necrotic leaves (12% and 2%), leaf surface ratio (1845 and 879 mm2/g dry weight), relative water content (80.83% and 52.40%), total chlorophyll (11.4 and 6.45 mg/g fresh weight), potassium content (0.378% and 0.322%) and lowest and highest sodium content (1.88% and 2.75%), relative ions leakage (14.85% and 30.02%) and sodium to potassium ratio (0.118 and 0.197) was observed in Chah Afzal with 100 kg/ha of calcium nitrate and Rebab Niriz without calcium nitrate application, respectively. Overall, Chah-Afzal was recognized as the most tolerant genotypes to saline condition. This genotype showed more suitable growth than the other genotypes by maintaining its growth characteristics and increasing potassium uptake compared to sodium. Also, the results showed that application of 100 kg/ha of calcium nitrate at the beginning of the growing season significantly improved the growth characteristics and reduced the harmful effects of sodium in all studied genotypes.

Lack of fresh water resources has led to production of salt tolerant species. This study was conducted in 2019-2020 to investigate the effect of irrigation water salinity on forage yield, plant height, and shoot ash content of Salicornia bigelovii and native Salicornia ecotypes including Bushehr (S. sinus persica), Central Plateau, Gorgan and Urmia of S. persica under irrigation with Persian Gulf (60 dS m-1) and groundwater (20 dS m-1), in Bushehr and Yazd conditions, respectively. Results showed that there were significant differences between the species and ecotypes in terms of fresh and dry weight of forage in both conditions. The highest fresh and dry weight of forage were related to Bushehr ecotype in both conditions, but the lowest of these traits were in S. bigelovii in Yazd and in Gorgan and Urmia ecotypes in Bushehr conditions. The amount of fresh forage for Bushehr ecotype were about 9333 and 22940 g m-2 in Bushehr and Yazd, respectively. In general, plant height under seawater irrigation conditions varied from 23.0 cm to 35.5 cm in Bushehr condition, and 56.5-78.0 cm in Yazd condition under saline groundwater. Regardless of species and ecotypes, the average shoot ash content in Bushehr and Yazd conditions were, respectively, 53.83% and 47.76%. Based on the results of the study, Bushehr ecotype could be considered as superior for planting and forage production in the southern coastal strip. In Yazd condition, due to better water quality, all species and ecotypes produced high fodder yield. However, due to high water requirement of Salicornia, its production in arid areas, especially in the central regions of the country, is not recommended.

There are several methods for desalination which could be divided into two classes of membrane and thermal processes. Other methods are also existed, of which, bioremediation (including phytoremediation), is the most important method. Halophytes are recognized as plants associated with the capability of tolerating those amounts of salt concentrations that could not be tolerated by other plants. Current investigation utilizes Atriplex Lentiformis plant as the purifier and solution of 15000 μS/Cm as the saline water. Three levels of plant density (0, 12, 24 plants) and four retention times (7, 14, 21 and 28 days) were considered in this study. This experiment was carried out without and with the presence of zeolite. Different parameters including; electrical conductivity (EC), concentration of calcium, magnesium, sodium, and chloride ions were measured before and after the treatment and the average reduction percentages of the proposed factors were measured. It was found that the zeolite treatments with 0, 12 and 24 plants reduced the EC 4.1, 13.4and 15.9%, respectively. Also, the concentrations of calcium, magnesium, sodium, and chloride ions were reduced 35.9, 25, 18, and 16.9%, respectively.

To assess the role of non-conventional water in arid regions, an Operational toolbox was designed comprising an integrated allocation model and a decision support module. The Water Evaluation And Planning System (WEAP) was used to define and calibrate the existing conditions. Possible scenarios for water supply (including conventional and non-conventional water) and consumptions (including drinking, agriculture and industry) where examined under current and potential future scenarios. A multiple attribute decision-making tool was utilised to rank various scenarios. The toolbox was used in an arid catchment of Iran, where indiscriminate use of conventional water resources, has posed a dominating water shortage.The results of the various scenarios showed that there is no scope to increase in agriculture allocation while the industrial allocation may be increased provided the non-conventional water is utilised to a certain extent. The results obtained from the toolbox has indicated that water transfer from other catchments is not an attractive option compared to the use of non-conventional water The results imply the effective role of recycling for the industrial water allocation, and desalination for the drinking water supply management.

Salt accumulation in the soil profile is a challenge for irrigated agriculture and the study of salt concentration and its variation in the soil profile under different irrigation systems and management is needed. In this study, Sodium, magnesium, calcium and SAR concentration were studied under three irrigation regimes; farmer management (I1), Irrigation requirement (I2) and I2 plus leaching requirement (I3) in Safaeyeh in Kerman during two cultivation years (1391-1392). According to the results sodium, magnesium, and SAR deceased after irrigation but calcium did not affect by irrigation time. In development growth period, the highest values of SAR, sodium and magnesium were found to be corresponded to 75, 50 and 75 cm soil depth, respectively. The highest values of sodium and magnesium in I3 treatment were 123.4 and 43.6 meq/lit which were corresponded to the soil depth of 75cm. The highest value of calcium in I3 treatment was correspond to the soil depth of 25cm which was 52meq/lit. The highest value of SAR (12.4) was belong to the soil depth of 75 cm which indicates calcium has moved upward and toward the emitter. The interaction effect of irrigation regimes, soil depth, and recording time (before and after irrigation) showed that the highest concentrations of sodium, magnesium and SAR were 131.8, 74.4 and 54.3 meq/lit respectively, which were belong to I3 and 75 cm soil depth before irrigation. The highest amount of SAR was 12.8 which were belonging to I3 treatment, too. Calcium variations in the soil under I2 and I3 irrigation regimes shows the important of irrigation management for salinity control. The results showed that I2 have better performance than the other irrigation regimes due to less salt accumulation and SAR values in the root zone.

Scion-rootstock combination and level of salinity affect on the biochemical characteristics of almond cultivars. To evaluate the effect of salinity stress on the biochemical reactions of almond cultivars and genotypes, a factorial experiment was carried out based on completely randomized design (CRD). Treatments included two factors: Factor A: genotypes in four levels (‘Shokofeh’,‘Sahand’ cultivars, and ‘13-40’ genotype budded on GF677 rootstock, and GF677 (without budding)), and Factor B: irrigation water salinity in five levels (0.5, 2.5, 4.9, 7.3 and 9.8 dS/m) .Total phenolic, antioxidant capacity, soluble carbohydrate, non-soluble carbohydrate, proline, total soluble proteins, hydrogen peroxide, malondialdehyde, other aldehydes, enzymes activity of catalase, ghayacol peroxidase and ascorbat peroxidase were measured at the end of the experiment. Results showed that, in all genotypes, with increasing salinity level (up to 9.8 dS/m) the content of hydrogen peroxide, malondialdehyde and other aldehydes was increased. Also, the content of total phenolics, antioxidant capacity, soluble carbohydrate, proline, total soluble proteins, enzymes activity of catalase, ghayacol peroxidase and ascorbat peroxidase were higher at the lower salinity levels (2.5 and 4.9 ds/m), but their contents were reduced in higher salinity levels. Overall, the highest content of soluble proteins, enzymes activity of catalase, ghayacol peroxidase and ascorbat peroxidase were recorded at salinity level of 7.3 dS/m, and the highest content of total phenolics, antioxidant capacity, soluble carbohydrate and prolin at salinity level 9.8 dS/m were observed in ‘Shokofeh’ cultivar. Also, at salinity levels of 7.3 and 9.8 dS/m, the lowest content of hydrogen peroxide, malondialdehyde, other aldehydes, and total non-soluble carbohydrate were observed in ‘Shokofeh’ cultivar. Finally, ’Shokofeh’ and ’Sahand’ budded on GF677 rootstock were recognized as the most tolerant and sensitive cultivars to salinity, respectively.

Irrigation with saline waters and solute transport to soil surface by capillary can accumulate solutes. Current study have been carried out to simulate the water flow and solute transport in soil by Hydrus model in order to determine the suitable depth of dripper in the grape garden that was located in Amirabad village in Birjand city in 2015.Samples were taken from the 0, 30, 60 and 90 cm of soil during the 3 irrigation interval and then the amount of soil sample moisture have been determined in the laboratory then the amount of moisture have been entered in Hydrus- 1D model. The amount of soil hydraulic parameters have been determined by inverse solution. Outputs of Hydrus- 1D have been entered in Hydrus- 3D model and the model have been executed. Results indicated that the amounts of Root Mean Square Weighted Error (RMSE), Mean Weighted Absolute Error (MAE) were 9 and 6 percent, respectively. According to the moisture and salinity profiles obtained from Hydrus-3D model, it was suggested to place dripper in depth of 32 cm. In order to check the accuracy of suggested depth Some Scenarios have been considered in Hydrus-2D model. In this scenarios, the dripper have been placed in the depths of 15, 20 and 25 cm. According to the obtained concentration profiles at the end of the simulation period for the mentioned depths, when the dripper have been placed in the depth of 25 cm, the amount of solute accumulation reaches to zero at the soil surface that confirms the results obtained by Hydrus- 3D so it is better to place dripper in the depth of 25-32 cm.

Production and growth of plants in many parts of the world due to degradation and water scarcity have been limited and particularly, in recent decades, agriculture is faced with stress. In the most parts of Iran, especially in the Khorasan Razavi province, drought is a fact and water is very important. Due to melon cultivation in this province, and the conditions of quality and quantity of water resources and water used to produce the melon product in this province, any research done on the use of saline and brackish waters is statistically significant. To study the effects of different water salinity and water management on some of the agronomic traits of late summer melon with drip irrigation, an experiment with 7 treatments and 3 repetitions was conducted in a randomized complete block design, in Torogh station, Mashhad. The irrigation treatments were: 1- fresh water from planting to harvesting, 2- water (3 dS/m) from planting to harvesting, 3- water (6 dS/m) from planting to harvesting, 4- water (6 dS/m) from 20 days after plantation to harvesting, 5-water (6 dS/m) from 40 days after plantation to harvesting, 6-water (3 dS/m) from 20 days after plantation to harvesting, 7-water (6 dS/m) from 40 days after plantation to harvesting. Row spacing and plant spacing were 3 m and 60 cm, respectively and the pipe type had 6 liters per hour per unit of meters in the drip irrigation system. Finally, the amount of salinity water, number of male and female flowers, number of seed germination, dry leave's weight, leaf area, chlorophyll (with SPAD) etc. were measured and all data were analyzed by using MSTAT-C software and all averages of data, were compared by using the Duncan test. Results and Discussion The results of analysis of data showed the following: Number of seeds germination: Salinity in water irrigation had no significant effects on the number of seed germination. However, there was the most number of seed germinations in the fresh water treatments. However, with increased water salinity, the time of seed germination reduced. The maximum delay in germination of seeds was in the treatment that was irrigated with fresh water from the beginning of cultivation. Number of flowers: First, the male flowers appeared and after 5 to 7 days, the appearance of female flowers began. The effect of irrigation treatments on female flower appearance was significant. With increased water salinity, the number of male flowers decreased. There was the lowest male flower in the treatment that was irrigated with saline water from the beginning, but there was no significant difference among the other treatments. Root, steam and leaves: The effect of saline irrigation water on dried leaves’ weight and dry root weight was significant at 1% and 5% levels, respectively. Fresh treatment and salinity treatment have the least and the most root dries weight, respectively (irrigated from the beginning with fresh or saline water). Two treatments that were irrigated with fresh and brackish water from thebeginning of cultivation have the highest leaf growth. The same trend was true for steams. In general, in all treatments, after applying different quality water to the end of the growing season, the trend of plant growth was similar to the others. Chlorophyll: One of the most common measurements made by plant scientists is the determination of Chlorophyll concentration. The SPAD index was used for comparison of chlorophylls. With an increase of the salt in irrigation water, the SPAD index was also increased. The maximum and minimum SPAD was in the treatments that were irrigated with saline water (treatment A) and fresh water (treatment C) from the beginning of cultivation, respectively. Yield: With increasing the salinity of water, the total yield decreased. Salinity in irrigation water had a significant effect (at the 5% level) on total yield. The mean yield of brackish and salinity irrigation water treatments were 17.5% and 26% less than the fresh water irrigation treatment, respectively.These differences were significant. However, there was no significant difference between the yield of cases using brackish or salt water. The results showed the following: Salinity in irrigation water had no significant effect on the number of seed germinations. However, there was the most number of seed germinations in the fresh water treatments, but by raising the salinity of water, the time of seed germination was reduced. With increasing the salinity of water, the number of male flowers decreased. There was the lowest male flower in the treatment that were irrigated with salt water from the beginning, but there was no significant difference between the other treatments. The effect of salinity water on leaf dry weight and dry root was significant at 1% and 5% levels, respectively. Fresh and salinity treatments have the least and the most root dry weight, respectively (irrigated from the beginning with fresh or salt water). Two treatments that were irrigated with fresh and brackish water from the beginning of cultivation have the highest leaf growth. The same trend was true for steams. Two treatments that were irrigated with fresh and brackish water from the beginning of cultivation have the highest leaves areas. And they had significant difference with other irrigation treatments. With an increase in the salt in irrigation water, the SPAD index also increased. The mean yield of brackish and salinity water irrigation treatments were 17.5% and 26% less than that of fresh water irrigation treatment, respectively.These differences were significant. But there was no significant difference between the yield of brackish and salt water.

In areas with high water table, due to evaporation from the soil surface, occurs accumulation of salts in the soil surface. Also the capillary rise of saline groundwater close to the surface, not only make evaporation from the soil surface and the loss of moisture but it entail soil salinization. Usually to prevent salinization of land, are used various methods to drain that these methods are envisage very the limitations of technical, economic and environmental existence. If you can prevent Another way of the capillary rise, can be expected to reduce the intensity of land salinization. So, the objective of this research was to evaluation the effect of the different levels of the superabsorbent polymer on reducing capillary rise from saline groundwater. This greenhouse experimentwas carried out in four levels of superabsorbent polymer 0 (control), 100, 150, and 200 g added to a fine-textured soil in the cylindrical with diameter and height 30 cm and 3 replicates. The results showed positive effects of superabsorbent polymer on reducing capillary rise. Between different levels of superabsorbent polymer, application of 200 g of polymer is make to reduce of the capillary rise of saline groundwater and reduce the accumulation of salts in the surface layer of the soil, than in the control (treatment without polymer).

The applications of organic and inorganic amendments in saline soils may alleviate salinity effects on soil microbial activity and biochemical characteristics. In order to investigate the effects of different levels of saline irrigation waters, and organic and inorganic amendments on soil respiration, and acid and alkaline phosphatase activities in the rhizosphere soil during vegetative growth of soybean a factorial experiment consisting of five salinity levels (i.e. S1= 0.8 S2= 1.6 S3= 3.2 S4= 4.8 and S5= 6.4 dS/m from the sea water source) and five amendment treatments including T1 (control without amendments), T2 (20 ton gypsum ha-1), T3 (20 ton manure ha-1),T4 (10 ton gypsum +10 ton manure ha-1), T5 (15 ton gypsum +15 ton manure ha-1) arranged as randomized blocks design with three replications was conducted using pots under greenhouse conditions. The results showed that with increasing salinity level, soil respiration and enzyme activities of acid and alkaline phosphatases decreased significantly, however, the reductions were not similar and comparable among amendment treatments. Soil respiration and enzyme activities in treatments receiving higher amount of the combined organic and inorganic amendments were greater than other amendment treatments. Increasing the salinity levels in treatment without amendments application caused the reduction of soil enzymes activities and respiration. Whereas, application of manure and gypsum together, as organic and inorganic amendment increased the soil enzymes activities and respiration. Results indicated that the maximum soil respiration occurred in T5 treatments and the greatest soil enzyme activities occurred in T3 treatments relative to the other treatments.

Great sturgeon is one of the most economically important species. However, in recent years overfishing, illegal fishing, etc., have resulted in severe declines in the stocks of this species. For conservation, stock of this species, determination of gonadal situation and its gonadal growth exchanges is very important. This paper is a histological approach to gonadal staging in 74 Huso huso in the 4 – and - 5 - year old classes. The fishes were reared in brackish water concert tanks under controlled conditions. A small section of the gonads of each fish was removed by biopsy. The gonadal tissue was fixed in buoin solution. They were dehydrated in different diluted solutions of alcohol and chloroform until they were clear. Then they were embedded in paraffin and sectioned at 7 µm and stained by hematoxylin and eosin method. Of the four-year old fish, %56 and %44 were males and females, respectively. %6 of males were at stage I %11 stage I-II %61 stage II %13 stage II-III %11 stage III-IV and %8 were at stage IV-V. %3 of the females were at unknown stage %3 stage I %11 stage I-II %60 stage II %14 stage II-III and 9% stage III. Of the 5 year old fish, %12.5 of males were at stage II % 25 stages II-III %50 stages III and %12.5 were at stage IV. %62.5 of females were at stage II and %37.5 were at stage II-III. Results of this study Compared with those obtained from fishes of the same age class studied in natural habitats as well as the results obtained for the farmed sturgeons from freshwater medium indicate that there is no similarly in the stage of gonadal development in different conditions. Longest stage in tow sexes was stage II that is longer in females, and passing of stage II in males is faster. Males showed more sexual maturity than females. Gonadic growth in culture medium is faster than wild condition, and it is faster in brackish water than fresh water. So, we can state that brackish water is a suitable medium for gonadic growth of Great sturgeon.