مجله آبیاری و زهکشی ایران
سال چهاردهم شماره 1 (فروردین واردیبهشت 1399)

Deficit irrigation is one of the ways to increase water productivity in irrigated lands. This study was conducted as a split plot experiment in a randomized complete block design with three replications on flat tomato cultivar at the Research Farm of Ferdowsi University of Mashhad, Iran, during the 2018 cropping season. Treatments included three irrigation methods including; usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying as main plots and three levels of deficit irrigation (50, 75 and 100% of field capacity) as subplots. Results show that the highest and lowest concentration photosynthetic pigments observed in the alternative partial root-zone drying and the fixed partial root-zone drying respectively. Maximum plant height (68.8 cm) was observed in fixed partial root-zone drying. Results show that, the maximum leaf area index (2.15), stem dry weight (76.5 g.plant-1), leaf dry weight (72.6 g.plant-1) and fruit yield (4.50 kg.m-2) was found in 100% field capacity. According to the results of the present study, the best result observed in usual irrigation, fixed partial root-zone drying and alternative partial root-zone drying respectively. Fruit yield in fixed partial root-zone drying was more than the alternative partial root-zone drying method.

Evening Primrose is one of the medicinal plants that have a high potential for Gamma linolenic acid production, which is essential as an intermediary in human body metabolism and Prostaglandins synthesis. In order to determine the effect of Salinity Stress and irrigation levels on morphologic and physiological characteristics of Evening Primrose, a pot experiment was conducted as a factorial based on completely randomized design with four replications in spring of 2018 at the Meteorological Station of Faculty of Agriculture, Ferdowsi University of Mashhad. The experimental factors consisted of irrigation treatments in 4 levels (100, 85, 70 and 55% Field Capacity) and salinity treatments at 3 levels (1.23, 4 and 8 ds/m). According on the results of this study, Evening Primrose plant could tolerate salinity and deficit irrigation stress before flowering at all levels. However, at flowering stage, it could not withstand the salinity levels at 4 and 8 ds/m and disappeared. Plant height, stem diameter and number of lateral branches in the interaction of stresses were less than Control treatment, while leaf length and width increased compared to control treatment. Simple irrigation effect was significant on electrolyte leakage in 0.01 level, chlorophyll b and Carotenoid in 0.05 level. deficit irrigation increased all physiological parameters compared to control treatment.

The objective of this research was to investigate the distribution and accumulation of salts under drip irrigation irrigated with saline water. To do so, two pistachio orchards in two regions in the Sarvestan plain (Fars Province) were selected. In most cases, soil sampling started 20 cm away from the tree and continued every 30 cm within the wetted area of the dripper perpendicular to the tree row with the last sample 60 cm out of the wetted area. Soil sampling was done to the depth of 150 cm with samples collected from every 30 cm. Soil sampling was done on both sides of the tree. Accordingly, 60 samples were collected for every tree in order to determine salinity condition around the tree accurately. Salinity of soil saturated extract and moisture content of all soil samples were measured according to the standard methods in the laboratory. Results showed that in one of the studied regions (7 dSm-1) accumulation of salinity has occurred minly under the the trees' trunk due to large distance between laterals and row of trees. In the other studied region (10 dSm-1) due to high flow rates of drippers, exceptionally high leaching of salts has occurred in part of the root zone. However, due to inappropriate agricultural practices, accumulation of salinity has occurred between the tree rows and also in the manure pits near the trees. Results also indicated that comparing average root zone salinity of soil saturated extract with salt tolerance of pistachio (measured under no water stress) can not show the the actual reduction in yield due to salt stress imposed on the crop. In the studied regions irrigation with high leaching fraction, reduces salinity of soil saturated extract to such an extent that its comparison with pistachio salt tolerance does not show that crop is exposed to high salinity stress. However, considering long irrigation interval in these regions, plant is exposed to water stress in some periods between irrigations evevts and therefore, soil water osmotic pressure could be increased to such an extent that reduces soil water potential up to the permanent wilting point limit and causes sever drop in crop yield. Therefore, appropriate irrigation scheduling under saline conditions is needed in these and other similar regions in order to reduce the adverse effects of salinity on growth and yield of the crop.

Drought in Iran is a climatic fact, and due to the growing demand for various parts of the water, the problem of water scarcity will become more acute in the coming years. Due to lack of water and for proper use of water resources, the importance of research on wheat irrigation by drip irrigation technique, has been increased in recent years. This study was carried out to investigate the effect of distance between drip lateral and amount of irrigation water on wheat water productivity in drip irrigation (tape) in two farms located in Mashhad (MHD) and Torbat-e-Heydariyeh(Rokh) (RKH) with Loam and clay loam soil texture respectively, were in the 96-95 crop year. The statistics design was complete blocks (factorial) and consisted of three lateral spacing (D1: spacing of 50 cm, D2: spacing of 75cm and D3: spacing of 100cm). The amount of irrigation water was also in three treatments (W1: 100%, W2: 75% and W3:50% of irrigation water requirement). The results showed that irrigation water treatment had significant effect on grain yield in both areas of the project and the highest yield was obtained from W1 treatment by 7537 and 5342 kg/ha in Mashhad and Torbat-e-Heydariyeh, respectively. Irrigation Lateral spacing also had significant effect on grain yield in both region and the highest yield was obtained from D1 treatment (7267 and 5920 kg/ha in Mashhad and Torbat-Heydariyeh, respectively). Interaction of irrigation water and Irrigation Lateral spacing (W-D) on water productivity in Mashhad region was insignificant but significant in Torbat-e-Heydariyeh region. The interaction showed that the best water productivity (1.72 and 1.52 kg/m3 in Mashhad and Torbat-e-Heydariyeh, respectively) was obtained in W3D1 treatment. Although W1D1 treatment (50 cm lateral spacing and 100% irrigation water) had the highest yield (8167 and 6104 kg/ha, respectively), they were in the c group in terms of productivity with W2D2 and W3D3 treatments.

In this study, contaminant transport from surface pollutant source to groundwater source through a hydraulic system consisting of three layers of soil is considered by using laboratory models and a numerical model. Three soil layers included two fine-grained layers and one coarse-grained layer between them. Arrangement from top to bottom consisted of a contamination tank containing sodium chloride solution as a source of contaminant, a clay layer with a physical barrier, a sand layer with a hydraulic barrier and a bottom placed clay layer as natural land and ultimately a fresh water tank as the groundwater source, receiving contamination. To study the performance of the hydraulic barrier, the physical and hydraulic properties of the used materials were calibrated in the CTRAN / W model. Then the calibrated model was validated using observational data with the extra conducted testes. Finally, hydraulic barrier performance at different hydraulic gradients and pressures was evaluated by numerical model. The results showed that the performance of hydraulic barrier is in the best condition when there is no gradient in the upper clay layer. Comparison revealed the hydraulic barrier efficiency is almost seventy percent better than the regular compacted liners without a hydraulic barrier. The studies also showed that the transmission of contamination to the receiving reservoir under positive gradient (downstream flow in the clay layer) was more in comparison to the negative gradient (upstream flow in the clay layer).

Climate change is a challenging topic for irrigation researchers as it has affected crop water demand. In the present study, the effects of climate change on minimum temperature, maximum temperature, precipitation, and the water demand of 12 crops including wheat, alfalfa, potato, barley, garlic, cucumber, watermelon, pumpkin, sugar beet, rapeseed, grain maize, and bean were investigated and also a trend analysis was carried out up to the year 2050. The impacts of implementing and not implementing the irrigation efficiency enhancement, the cropping pattern changes and the development of the early-maturing cultivars as the adaptation strategies in combination with climate change scenarios were investigated between the water years 1399–1428 (2020–2050). The results showed that without implementing the adaptation strategies, the net irrigation water requirement would increase by 3.98% to 8.38% compared with the recorded data. Growth in the irrigation efficiency up to the potential efficiency would cause a 19.23% reduction in the gross irrigation requirement on the average. By implementing the cropping pattern changes strategy through stopping the cultivation of some water-intensive crops such as alfalfa and developing the cultivation of rapeseed, net irrigation water requirement would decrease by 10.9%. By replacing late-maturing potatoes by the early and medium-maturing cultivars and developing of early-maturing grain maze cultivation, net irrigation requirement decreased by 8.86%. Furthermore, the results revealed that implementing all the above-mentioned adaption strategies would reduce the gross irrigation requirement by 34.0%. Hence, the three above-mentioned strategies can be used as the measures that executive managers and farmers choose to implement in order to adapt to climate change.

The present study investigates the physics of the flow and the role of coherent structures of flow in the scouring process, around a vertical dike, located in a straight channel, at the beginning of scouring process (flat bed). Therefore large eddy simulation (LES) method is applied for a flow with a relatively low Reynolds number (Re=18000). The inflow is thoroughly turbulent and full of realistic turbulent fluctuations. After visualizing the flow, it was found that the intensity of the primary horseshoe vortex (HV) is largest at vertical sections around the tip of the dike. In this region, the core of the horseshoe vortex fluctuated between two modes. In one of them (zero-flow mode) the horseshoe vortex gets closer to the dike and the beneath flow jet gets weaker. In the other one (back-flow mode), the jet flow near the bed, takes the horseshoe vortex farther apart from the dike. As a result, in the distribution of turbulent kinetic energy and pressure fluctuations, two peaks are observed. The largest amounts of bed shear stress are present in the acceleration zone of flow near the tip of the dike, upstream of detached shear layer (DSL). The tail of the horseshoe vortex occasionally interacts with the vortex tubes shed in DSL and the tip of the dike. Furtherrmore some of the vortices shed in DSL may sometimes interact with each other or with the vortices present in the recirculation region behind the dike. This leads to amplification of bed shear stress along their path.

Soil infiltration models play an important role in the design and evaluation of surface irrigation systems. The purpose of this study was to evaluate, compare and calibrate water infiltration models in some areas of western Iran including Davood Rashid and Honam in Lorestan province and Kalat in Ilam province. Influence models including Kostiakov model, Modified Kostiakov model, Novel, Horton, SCS and Philip’s models were investigated. To evaluate the accuracy of the models, the calibration indices including RMSE, MAE, MR, PE and R2 were used. Model calibration was performed using Solver Excel software. Evaluation indices showed that Novel infiltration model with mean values of RMSE, MAE, MR, PE and R2 had 0.0221, 0.0178, 0.999, 0.13 and 0.9785 respectively. It performs better than the other five models in the whole study area. On the opposite side of the SCS model with mean values of RMSE, MAE, MR, PE and R2 were 0.07, 0.0575, 1.07, 7.86 and 0.8021, respectively. It was the most inappropriate performance. Whereas the analysis of variance of the models showed no significant difference between the calculated and measured values. In the regional study of these models, the Novell model was also chosen as the most suitable model for all three regions of Davoodershad, Honam and Kalat. Evaluation of model performance in different tissues indicates less sensitivity of modified Horton, Novel, Kostiakov and modified Kostiakov models to soil texture changes and better SCS model performance in heavy tissues and better model performance Philip was in lighter-textured textures. Therefore, Novell model can be used to estimate infiltration under different soil texture conditions as well as under similar conditions in the study area.

Drought stress and its impact on cover crops is one of the most important studies in plant research. So, the use of modern techniques to provide greater resistance to environmental stresses is necessary. In this study, investigated the effect of zeolite on some morphological and physiological traits of Festuca arundinacea grass under drought stress. A factorial experiment based on completely randomized design with 2 treatments and 3 replications was conducted in horticultural science greenhouses of Ferdowsi University of Mashhad in spring and summer of 2018. Treatments included 3 levels of drought stress based on field capacity (FC): (100% (control), 50% and 25%) and 3 levels of zeolite mixed with loam: (0, 10% and 20% w / w). According to the results, irrigation levels of 50% and 25% resulted in reduced vegetative traits, decreased relative water content and increased ion leakage, proline and total carbohydrate content in the plant. The interaction effects of zeolite and drought stress showed that treatment with 20% zeolite had the highest leaf area (31640 cm 2), total dry weight (78.21 g) and carotenoids (2.16 mg/g fresh weight) and the lowest ion leakage in non-stress conditions. application of zeolites especially at 20% level resulted in increased growth traits such as fresh and dry weight of roots and shoots, leaf area, height and carotenoids. The results showed that zeolite improves plant growth traits and can reduce the damaging effects of drought stress on grass.

One of the new structures of water level regulation in irrigation canals is the Lopac gate which has several advantages such as overflow and non-accumulation of sediments. The elliptical-lopac gate (ELG) is a new type of lopac gate that introduces a higher discharge coefficient than the rectangular lopac gate (RLG) as well as the easier passage of floating objects in the flow. In the present study, the effect of sudden transition on the discharge coefficient value of ELG in submerged flow conditions has been evaluated in the laboratory. The results showed that the sudden transition in the ELG reduces the discharge coefficient 14 to 73% compared to the channel width conditions. Also, the discharge coefficient has a direct relationship with the Froude number and opening angle of the ELG and the inverse relationship with the rate of channel narrowing due to the transition and submergence of the ELG. Finally, the empirical equations were presented to estimate the discharge coefficient of ELG with sudden transition under submerged flow conditions with a maximum error of 5% and 15%.

The aim of this study was to evaluate the remote sensing algorithm (SEBAL) for estimating actual evapotranspiration in Vardij area in Tehran province. For this purpose Landsat 8 satellite images on June 10th, July 12th, August 13th and September 14th, 2018 and July 15th, 2019 were used. The reference evapotranspiration value (alfalfa plant) was calculated using evapotranspiration obtained from the SEBAL algorithm for the three points where alfalfa was previously cultivated. Using the meteorological station data, reference evapotranspiration was estimated by the experimental methods of FAO Penman- Monteith, Penman -Wright, Hargreaves Samani and Blani Cridel. The values obtained from SEBAL algorithm were compared with the mentioned methods and it was observed that in the study area the Hargreaves Samani method (MAE = 0.472 and RMSE = 0.62) was closer to the remote sensing method. Next in rating is the FAO Penman Monteith method (MAE = 1 and RMSE = 1.26). Finally, the evapotranspiration obtained from SEBAL algorithm was compared with the value obtained from portable lysimeter and the results showed good correlation, so that absolute difference value was 0.81 (mm/day), and it can be concluded that the remote sensing method is suitable for estimating evapotranspiration in the study area.

This research was carried out to investigate changes in bean water stress index and its relationship with soil moisture under different regimes of drip irrigation at Lorestan University College of Agriculture.For this purpose, three varieties of Pinto bean Contains sadri (S), COS16 (C) and Kusha (K) in main plots and irrigation regimes in four levels including T120 (120% crop water requirement), T100 (100% crop water requirement) T80 (80% crop water requirement) and T60 (60% crop water requirement) were subplots.The results showed that in all three cultivars of the beans, the highest values of CWSI during the season were related to severe tension (T60) which was equal to 0.3 and in contrast to (T120), the lowest values of water stress index and Equal to 0.14. The correlation coefficient between of soil moisture content and CWSI was found to be 0.91 which was significant at 1% probability level, and Therefore a relation was used to estimate the soil moisture content using the crop water stress index. Finally, using the proposed relationship and the allowable drainage coefficient, the threshold value of CWSI was 0.21.

Non-commercial and peaceful application of valid and advanced international technologies compatible with human and environmental health, for the complete and scientific treatment of toxic contaminants imposed on clean water resources, for optimal use of the ultimate blessings of the absolute Creator (GOD) of the world, and the elimination of human self-made problems has a particular importance. For this purpose, in the present study, a descriptive and cross-sectional study was performed on the Hamadan wastewater treatment plant operating with an activated sludge treatment system from December to February 2018-2019. In the evaluation of the treatment plant, five quality parameters of inlet and outlet wastewater were measured twice a day and in total six times per month. Then, while analyzing the results by SPSS software, graphs of these parameters were plotted with Excel software. The results showed a relative decrease of 96.27%, 20.20%, 96.11%, 94.23% and 7.16% of TSS, COD, BOD, NTU and pH parameters, respectively. As a result, the treated wastewater, due to its very low acidic properties, can be used in the electric power industry. Also, despite the permissible short-term use of contaminated wastewater in agriculture and the environment, further international validation of their application is essential for the sensitivity of the risk to the increasingly catastrophic and irreparable carcinogenicity of incomplete wastewater treatment.

Evapotranspiration is one of the most important factors in the hydrology cycle and is one of the determinants of energy equations at ground level and water balance. Most of the ground-based methods use point measurements to estimate evapotranspiration. Remote sensing has the ability to estimate the amount of evapotranspiration and examine its spatial distribution. In this study, Landsat8 and Sentinel2 satellite images combined to estimate the actual daily evapotranspiration of sugarcane in the Mirza Kouchak khan Agro industrial Company, Khuzestan province, using the SEBAL model at six dates.Validation of SEBAL model performance was performed in two modes: using integrated images and using Landsat 8 images with lysimeter data. The results indicated that the SEBAL model with Landsat 8 satellite images with (R2=0.88), and the SEBAL model with Landsat 8 and Sentinel2 satellite images with (R2=0.90), Overall, it was well correlated with the lysimeter method and estimated similar and appropriate results.

Low participation and poor temporal and local distribution of rainfall in Iran and the importance of food security and sustainable agriculture make the need for proper and scientific use of water resources inevitable. In this study, optimal utilization of water resources of Ajbashir Qaleh Chay Dam in agricultural sector was investigated using extended Interval two - stage stochastic programming (ITSP) and extended ITSP with fuzzy variables. The data were collected from Regional Water Company and Agriculture Jihad Organization of East Azarbaijan in 2015-16, and in some cases, completed by a questionnaire. The model were written in the GAMS package. Results of extended ITSP showed that if the optimization method is used, the final allocation of water is zero, at low flow level for wheat and grape, at normal flow level for wheat, barley and grapes, and at high current levels for wheat and potato. The results of extended ITSP with fuzzy variables shows that the final water allocation at low flow level for wheat and grapes, at the normal flow level for wheat, barley and potato and at high current levels for wheat , barley and onion is zero. For the rest of the products, the optimal water allocation target is provided based on this optimized model. Comparing the total system profits of the two models shows that in the fuzzy model, the profit and system certainty increases simultaneously. Therefore, due to the lack of water resources in the agricultural sector and uncertainty, the officials of agriculture in Ajbashir by providing an optimal model while increasing farmers' profitability, reduce the unsustainability of water resources.

Flood routing is a technique to determine downstream flood hydrographs that is important. The Muskingum-Cunge method is one of the flood routing methods. In the present study, the accuracy of the Muskingum-Cunge method is investigated using the river reach located between the Mollasani hydrometric station in the upstream, and the Ahwaz hydrometric station in the downstream of the Karun River. The results indicated that using three different values for the parameters of the Muskingum-Cunge method instead of using a constant value as well as the monoclinal wave equations in calculation of the kinematic wave velocity, the accuracy of the Muskingum-Cunge method in estimation of the outflow hydrograph increased. In the present study, the inflow hydrograph was classified into the start, peak, and end of the flood sections, and different values for the parameters of the Muskingum-Cunge method were calculated for each of the three sections. In addition, using the Particle Swarm Optimization (PSO) algorithm, the time step (Δt) of the three sections was also optimized, which in turn improved the calculation accuracy of the Muskingum-Cunge method in estimation of the outflow hydrograph. The Mean Relative Error (MRE) and Relative Error in estimation of the peak discharge (DPO) by using the conventional Muskingum-Cunge method with constant parameters and a time step of 1 hour was calculated as 6.15 and 7.63 percent, respectively. However, using the proposed method in the present study, the corresponding error values of 1.69 and 4.9 percent were obtained, respectively.

Wheat is the main source of food production in Iran. Khuzestan and Fars provinces are the two main poles of production in Iran. Determination of wheat yield components is of particular importance in the planning of planting and production of this crop. In this study, wheat yield in different growth stages was estimated using canopy cover as well as wheat biomass using satellite imagery. NDVI and LWCI indices from Landsat 8 satellite images were used to determine canopy cover and biomass at four fields in Darab and Zarangan in Fars and Dezful and Omidiyeh in Khuzestan during two crop years. Canopy cover was determined by field imaging and application of ENVI software; and biomass was measured during growing season by field sampling to compare with estimated values obtained by remote sensing. A linear relationship was found between canopy cover and NDVI with a R2=0.88. The coefficients of determination of this relationship in Dezful, Omidieh, Darab and Zarghan were 0.96, 0.93, 0.95 and 0.89, respectively. Biomass was determined using remote sensing indices and average biomass of each region, during the growing season. Model efficiency values based on EF index for biomass estimation in Dezful, Omidiyeh, Darab and Zarqan were 81, 71, 82 and 80 percent, respectively. Plotting NDVI values over time during the growing season also provided a method for estimating the appropriate wheat planting date. This study presented a low-cost and less-time consuming method for passing difficult field measurements that can be used to estimate canopy cover, biomass, and wheat planting date in the study areas.

Accurate estimation of hydraulic jump characteristics such as energy dissipation amount has significant impact on optimum design of hydraulic structures. In this study, hydraulic jump relative energy dissipation was investigated in different sections channels (containing rectangular, sudden expanding, and trapezoidal sections) with different rough elements and with different arrangement using Gaussian Process Regression (GPR). In this regard, the parameters which had most correlation with energy dissipation were determined using factorial analysis. Then, different models were developed and using experimental data the impact of channel type and rough elements on energy dissipation was investigated. The obtained results of models analyzing showed the high efficiency of applied method in estimation of energy dissipation. It was observed that developed model in expanding channel with central block led to more accurate results in comparison with two others channels. For this channel, the model with input parameters of F1 and (y2-y1)/y1 was selected as superior model and the best result for test series was obtained the values of R=0.995, NSE =0.987 and RMSE=0.021. Also, it was observed that the channel rough elements characteristics had impact on predicting the relative energy dissipation and between two rough elements with strain and staggered arrangement, the obtained results for strain state were more accurate. According to the results of both factorial and omitted sensitivity analysis it was indicated that Froude number is the most significant parameter in estimation of relative energy dissipation.

The nitrogen cycle in the soil is an important part of the nitrogen cycle in the world and is largely influenced by climate change. The developed model was calibrated and evaluated by system dynamics method in order to simulate nitrogen behavior in soil in Amirkabir sugarcane Agro-Industry. Data from complete irrigation and fertilization treatments (depth of irrigation was 120 mm and 4 split equal to 450 kg.ha-1) were used to calibrate the model. Also, treatments of 150, 250 and 350 kg.ha-1 were used to evaluate the model. In order to goals of this study, the output of three models of BNU-ESM, CESM-CAM and EC-EARTH was applied with two scenarios RCP2.6 and RCP8.5. The results showed that climate change would increase nitrate losses, mineralization and ammonium sublimation. The amount of nitrate losses in the EC-EARTH2.6 climatic pattern showed an increase of 5% for future period (2016-2035) compared to the base period (1971-2000). Mineralization in the base period was equal to 93.5 kg.ha-1, which is less than the values obtained with less variation models. This phenomenon also reduces the process of denitrification from 29.65 to 20.1 kg.ha-1. The change from the RCP2.6 to RCP8.5 scenario has led to an increase in nitrate losses, mineralization and ammonium volatilization, which indicates the effect of increasing the concentration of carbon dioxide gas on these processes.

In this study, dry matter yield and water productivity of five clones of potato under irrigation conditions at 100, 90, 80, 70, 60 and 50% water requirement levels were evaluated by AquaCrop model. Field experiments were conducted in split plot design based on randomized complete block design with two years at Ekbatan station of Agricultural and Natural Resources Research Center of Hamedan province. After sensitivity analysis, the results of the first year experiments were used for calibration and the results of the second year experiments were used for model validation. The results showed that this model had an average error of 10.95 and 47.34% in simulating yield and water productivity of potato, respectively. Therefore, this model was less accurate in estimating water productivity than the appropriate estimation of potato yield. Under water shortage conditions, Clone 397008-2 had the highest yield and water productivity at 80% of water requirement with 16.39 ton ha-1 and 3.41 kg m-3, respectively. Therefore, it is recommended that this clone and irrigation use 80% of the water requirement by the farmers in the region to achieve 20% water saving and maximize potato yield and water productivity.

In order to study the effect of two factors of irrigation deficit (drought stress) and superabsorbent polymer ‎application on morphological characteristics, plant yield and yield components of green bean, two experiments ‎were conducted in a completely randomized design with factorial arrangement in greenhouse conditions in ‎Educational- Research Greenhouse, Faculty of Agricultural, Mashhad Branch, Islamic Azad University, ‎Mashhad, Iran during in cropping season 2017-2018. In both experiments: experimental factors were included, ‎superabsorbent polymer in 4 levels (0, 3, 5 and 7 g per kg of soil) and irrigation deficit in 4 levels (20, 40, 60 and ‎‎80 % decrease of soil water weight based on Field Capacity). In the first experiment 3 and in the second ‎experiment, 6 replications were considered. The results of analysis of variance showed that in the first ‎experiment, effect of irrigation deficit, superabsorbent polymer and interaction between two factors had ‎significant effect on the plant height, number of leaf, fresh and dry weight of plant, leaf area, number of pod ‎per plant and fresh pod weight. In the second experiment, effect of irrigation deficit and superabsorbent ‎polymer on number pod per plant, number of grain per pod, grain yield per plant and biomass were significant. ‎But, in the second experiment, interaction between to factors had only significant effect on number of pod per ‎plant, grain weight per plant and biomass. In both experiments, means comparison under the influence of ‎irrigation deficit and superabsorbent polymer showed that with decreasing of 40% moisture from field capacity, ‎all traits were decreased. In general, the results of this study showed that application of superabsorbent polymer ‎caused of decreases the negative effects of drought stress.‎

Using the simulated models can help the users to approach the attitude of applying different managements. Therefore, identifying and evaluating the models in this case is non-negligible. The Daisy model is one of the most comprehensive models for simulating of the water-soil-plant-atmosphere system whose performance was evaluated in this study. Based on the data of three irrigation treatments: Full irrigation (FI) and deficit irrigation (DI) at 75% and 55% level during two years, the conditions were defined in the model and the crop submodel was made for the sunflower. The yield parameters were measured and compared with simulated values based on R2, NRMSE and efficiency coefficients (EF). The model was validated based on the results of full irrigation treatments and the model performance was also evaluated based on irrigation treatments. The results showed that Daisy has a very acceptable performance by the mean of NRMSE for the leaf area index(LAI), height(H) and dry matter(DM) and water content estimated 0.059, 0.036, 0.031 and 0.064 and the mean EF were equal to 85.67, 33.82, 91.5 and 67 percent. the rang of R2 was 0.799-0.999. The significance of the difference between simulated and observed values was compared by T-test for the paired samples in SPSS. The total results showed that the model could simulate the full irrigation better than the deficit irrigation. In general, Daisy could be used as an applied model to simulate the conditions of irrigation projects under different management.

In recent years, pressured irrigation methods such as trickle irrigation systems have been developed to optimize use of limited water resources in the country. Therefore, this research was carried out with the aim of investigating the technical and economic effects of trickle irrigation in some fields of Hamedan province during 2017 to 2018. For this purpose, 14 cucumber and tomato fields were randomly selected and studied. The amount of irrigation water was calculated by installing flow meters or by measuring the water source discharge, the irrigation time per turn and the number of irrigation. To study soil salinity changes, soil samples were taken at the beginning and at the end of the growing season and Soil salinity was determined. The average amount of water consumed and water productivity in cucumber and tomato were 7948, 10255 m3ha-1, and 8.7 and 7.2 kgm-3 respectively. The results showed that despite the use of trickle irrigation system in some fields, although water productivity increased but irrigation water volume was a lot due to improper implementation and poor management of the irrigation system. Comparison of water requirement with consumed irrigation water in some cucumber fields indicated deficit irrigation in these fields. The results also showed that soil salinity increased more under the irrigation strips than between the irrigation strips at the end of the irrigation season compared to the beginning of the irrigation season. The average was 0.50 dS. m-1. Economic analysis of the results showed that using of drip irrigation system in tomato and cucumber products has high economic returns in all studied fields, So that the profit cost ratio for cucumber and tomato fields was 26.9 and 7.8 respectively

The water, food and energy nexus is an important approach in a comprehensive assessment of water resource management policies. The main objective of the current research is providing a method for decision makers to analysis and quantitative assessment of water–food–energy nexus at the irrigation network level. Through the proposed method, indicators considering the water and energy consumption, water productivity, and energy productivity were suggested. Based on these indicators a water–food–energy nexus index (WFENI) was proposed. This research was conducted on irrigation networks located in the Zayandehrood basin in Isfahan province. The Water Evaluation and Planning (WEAP) Model has been used to simulate the allocation of resources and basin utilization conditions. Different scenarios were analyzed to existing water resources, energy consumption, and crop patterns. Considering the normalized water productivity index solely, the best scenario is a 20% reduction in water release from zayandehrood dam, with a maximum value of 0.54 for the Nekouabad irrigation network. Based on the normalized energy productivity index, the best scenario is the blockage of illegal wells with a maximum value of 0.49 for the Northern Mahyar irrigation network. While, taking into account the combined index, the prioritization of scenarios in different networks has changed. The results of this research indicated that although each of the Productivity Index alone reflects the effects of each policies in different networks, but based on only one indicator, it is not possible to decide on the effectiveness of the policies. It can be stated that the simultaneous consideration of water, food and energy is essential in analyzing the operation of irrigation networks and in selecting best policies

In this study, three-dimensional flow around the labyrinth side weir was simulated by using a variety of Subgrid-Scale (SGS) models in LES method and four turbulence models based on RANS method with different computational grid size in ANSYS Fluent software. The simulation and experimental results were compared. The predicted flow discharge and water surface profile were validated using experimental data and the proper Subgrid-Scale (SGS) model in LES method was selected for hydrodynamic and parametric studies and were compared with the proper turbulence models based on RANS. All numerical values are very close to experimental values. Although the predicted water surface profile by turbulence models based on RANS method (K-ε-Standard model) was better than of LES Method, but the results of the hydraulic analysis showed that all Subgrid-Scale (SGS) models in the LES metod can be predicted the complex flow patterns and behaviors in more detail than turbulence models based on RANS method. As the result of flow discharge and water surface profile and also high relatively confidence in the ability of large Eddy Simulation method, the velocity, shear stress distribution and secondary flow channels with labyrinth side weir were investigated

This research was carried out to determine the optimal water-yield function for cotton plant and to evaluate the cotton production indices in a factorial based on a completely randomized block design with three replications for one year in Sarayan area. The research factors included four levels of I1, I2, I3 and I4 irrigation depths of 50, 75, 100 and 125% of the plant water requirement as the main factor and two cotton cultivars (V1Varamin and V2Khordad) as a sub factor. The best production function was selected from four production functions (linear, CubbDuglass, Quadratic, and Transcendental) for two cotton cultivars. For both cotton varieties of Varamin and Khordad, the second-order function was selected as the optimal production function. The average final production index for irrigation water in Varamin was 37/80 kg / ha for irrigation water depth per centimeter and 36.71 for cotton in Khordad. The final production value of irrigation water (VMPi) for cotton in the Varamin variety was equal to 2268185 Rials and for cotton in Khordad 2202727 Rials. Comparison of these figures indicates that Varamin cotton is more resistant to water shortage and more economical in terms of cultivating it in Sarayan area.

In order to evaluate the effect of different irrigation management, a split-split plot design was carried out in a randomized complete block design in Shahrekord Agricultural and Natural Resources Research Center in the growing season of 2018. This experiment consists of two methods of irrigation (surface and subsurface drip irrigation) in the main plots and four irrigation levels (Full irrigation, FI; deficit irrigation, RDI-80; Regulated deficit irrigation, RDI-65; and Partial Root-zone Drying (PRD-75) in subplots, in three replications for potato (Bourren cultivar). The results showed that the effect of different irrigation management on tuber yield, number of tubers per plant, percentage of tubers size, dry matter percentage, normal harvest index, percentage of starch, percentage of soluble sugars, percentage of nitrate and water productivity were significant (P≤0.01). Surface drip irrigation, as compared to irrigation of subsurface drip, increased the yield and water productivity by 7%. For surface irrigation, by increasing the amount of irrigation water from 65% to 100%, the average of starch and nitrate increased 18.8% and 33.6%, respectively and the soluble sugars decreased by 13.8%. With Compared to different irrigation treatments in two irrigation systems, average of maximum yield and normal harvest index for complete irrigation were obtained 50.3 t/ha and 0.48, respectively. In surface irrigation and 〖RDI〗_80 treatment the highest water productivity was achived 12 kg/m^2 which is recommended as a water saving solution.

Drip irrigation benefits enhanced the worldwide use of this irrigation system. drip irrigation reduces significantly the wetted soil surface that lead to reduction of evaporative losses. claimed that wetting pattern is a major parameter in optimizing lateral placement and emitter spacing as well as in selecting emitter’s discharge. In other word, to achieve proper drip irrigation design, dimensions of the wetted zone (depth and width) should be accurately determined. Therefore, present study was conducted under clay loam soil to investigate the accuracy of numerical (HYDRUS-2D) and empirical (multivariate nonlinear regression) models in estimating wetting pattern for surface drip irrigation. The predicted values of soil moisture, wetted depth and width were compared with those obtained from laboratory experiments. Experimentations included determination of soil moisture, depths and widths of wetted zone after 1, 2, 3, 4, 5, and 6 hour of water application with three different discharge rates (2, 4 and 8 L/h). Statistical parameters revealed that there was no significant difference between models results and observed values. So that The normalized root mean squared error (NRMSE) varied from 5.8 to 8.2% and 7 to 7.7% for numerical and empirical models, respectively. The results also showed that The proposed empirical model predicts the wetting pattern with acceptable accuracy.

Since the agriculture field is the main water consumer, using techniques in order to increasing water use efficiency is necessary. Due to the limited freshwater, farmers have to use unconventional water, such as Wastewater, Fishery Wastewater and Saline water. In this study, Four Quality of water is evaluated on yield and yield components of Quinoa (CV. Titicaca). the research was done based in completely randomized design including 3 replications as pot planting in Ferdowsi University of Mashhad in Greenhouse conditions, during 2017-2018. In this study, four irrigation regimes existed of (fresh water, Wastewater, Fishery wastewater and saline water). The results showed that effect of different quality of water on shoot fresh and dry weight, stem diameter SPAD index and leaf area was significant at 1 percent level (P<0.01), but plant height and branches number was significant at 5 percent level (P<0.05). in this study, all of this parameter decreased significantly with irrigation by saline water. in this study, increased all of this parameter with irrigation by wastewater and fishery wastewater.

Water desalination using the RO system is expanding. Due to large volume of brine in the treatment system, its recycling for irrigation can be an effective step in sustainable development of environment. In this study, treatment of RO brine was performed in three phases; with graphene oxide solution, with graphene oxide sludge, with graphene oxide solution and then graphene oxide sludge. The results showed percentage decrease of electrical conductivity of brine with graphene oxide solution was equal to %48.84 (decrease from 12000µs/cm to 6139µs/cm), with graphene oxide sludge equal to %10 (decrease from 12000µs/cm to 10800µs/cm), with graphene oxide solution and then graphene oxide sludge %51.9 (decrease from 12000µs/cm to 5772µs/cm). pH of treated brine with graphene oxide was constant with little change or no change. The results were in accordance with water quality guideline and standard of Iran country for irrigation. The advantages of this method of treatment were ease and speed of work in a short time up to maximum 10 minutes. Graphene oxide sludge was thicker and less, compared with sludge in most conventional water treatment processes. Due to the carbon structure of the resulting sludge, it can be dried and then it can be disposed in environment. Based on the results, it seems the new treatment method of brine with graphene oxide can be used for RO systems as an environmental-friendly method.