mohammad albaji

In Iran, where there are 40 million acres of desert land, faces many challenges in combating desertification, the most significant of which is wind erosion. Afforestation is the easiest solution to deal with this phenomenon. Given the quantitative and qualitative limitations of water resources, selecting the appropriate irrigation method for rangeland plants is of great importance.In order to determine the most appropriate irrigation method for various rangeland plants, this study was conducted for two years (2019-2021) at Shahid Chamran University of Ahvaz. The experiment was conducted in a factorial design within a randomized complete blocks design with three replications.The main levels included four types of rangeland plants (Prosopis cineraria (T1), Conocarpus (T2), Albezia lebbek (T3), and Ziziphus (T4)), and the sub-levels included four types of irrigation (surface (I1), waterboxx (I2), pitcher (I3) ) and Bubbler (I4)).The results of the analysis of variance showed that the types of rangeland plants had a significant difference at the 1%  level in terms of measured indices (plant height, stem diameter, stem dry and wet weight, dry and fresh leaf weight, leaf area index, and water consumption volume, and water productivity). There was also a significant difference between irrigation methods at the 5% level  for all indices except stem diameter and leaf area index. Among the plant species, mesquite had the highest coverage (including height and dry and fresh weight), and the lowest amount of water consumption (averaging 996 liters per plant over two years), and the highest water productivity (9.72 kg/m3). Among the irrigation methods, the bubbler irrigation method had better coverage than other methods. In contrast, the waterbox irrigation method was superior in terms of water consumption and water productivity, saving 87% of water compared to surface irrigation and  increasing water productivity by 298%. Therefore, the waterboxx irrigation method can replace other irrigation methods in afforestation and desertification projects

The Crop Water Stress Index (CWSI) is a practical method for monitoring plant water status, detecting the onset of moisture stress, predicting crop yield, and irrigation schedule for variouscrops. The CWSI values range from zero to one, where zero indicatesthat the plant is not uunderwater stress and has the most ideal conditions for transpiration, while a value of one signifies maximum water stress and complete cessation of transpiration. The present research was conducted to calculate the CWSI,determine the moisture stress threshold for safflower and identify optimal irrigation management practices by analyzing the relationship between the CWSI and various deficit irrigation managements  approaches.The research was carried out over two agricultural seasons, 2020-2021 and 2021-2022at Khuzestan University of Agriculture and Natural Resources. The experiment used a randomized complete blocks design with a conventional irrigation treatment (CI) and four deficit irrigation treatments including (RDI80, RDI60: deficit irrigation adjusted by supplying 80% and 60% of soil moisture deficit, respectively) and (PRD80, PRD60: deficit irrigation in the form of partial root zone drying methods with 80% and 60% of soil moisture deficit, respectively) and with four repetitions. Results showed that the CI treatment had the lowest value of 0.17 and the RDI60 treatment had the highest CWSI at0.67. Irrigation planning was done with the aim of achieving the maximum efficiency of water productivity, and based on this, the relationship between the permissible limit of the temperature difference of the Canopy cover of the plant and the air for the months of March ((Tc-Ta)a = 1.618 - 0.215 VPD), April ((Tc-Ta)a = 2.46-0.220 VPD) and May ((Tc-Ta)a = 4.636-0.164 VPD) were obtained. The moisture stress threshold for safflower was obtained from the regression relationship between the CWSI and the temperature difference of the Canopy cover of the plant and the temperature of the surrounding air (Tc-Ta) equal to 0.61, which was introduced for the study area and with the research conditions

Tomato (Solanum lycopersicon) is one of the most consumed vegetables in the world due to their abundance of vitamins, lycopene, iron, calcium, manganese, magnesium, and potassium. Khuzestan, with a production of over 21,000 tons of tomatoes in 90 hectares of greenhouses, ranks fourth in the country after the provinces of Bushehr, Isfahan, East Azerbaijan, and Sistan and Baluchestan (the total area under tomato greenhouse cultivation in Iran is over 2400 hectares). Due to the trend of drought in Iran, providing the required water for this level of cultivation will be one of the main challenges and concerns of farmers in the future. Therefore, the necessity of attention to water supply for this level of tomato greenhouses, considering the dry and semi-dry nature of the country, seems to be crucial. One of the biggest recent challenges in Iran is the limitation of water resources, which has reduced access to water for both human and agricultural uses due to low levels of rainfall, poor distribution, high evaporation and transpiration rates, and the phenomenon of drought. To overcome the water shortage, the use of aquaculture wastewater or its combination with agricultural water can be a solution due to lower water and chemical fertilizer consumption, as well as prevention of the release of nutrient-rich water sources into rivers. This can be one of the helpful management strategies in solving the water shortage problem in dry and semi-dry regions for agricultural production.

To investigate the effect of using fish pond wastewater on the morphological and growth characteristics of three greenhouse tomato cultivars, a factorial experiment was conducted in a completely randomized block design with three replications in the greenhouse of Shahid Chamran University of Ahvaz during the autumn and winter of 2021-2022. Tomato seedlings were first produced under LED light in a room and transferred to 9-liter pots with a row spacing of 90 cm and a plant spacing of 30 cm at the 3-4 leaf stage. The planting media used in this experiment was sand which was washed several times with purified water before use. The treatments in this experiment consisted of three types of nutrient solutions (Resh nutrient solution, fish pond water, and modified fish pond water) and three promising greenhouse tomato cultivars (V4, AZ4 and AZ5). In order to modify the fish pond water, 50 liters of tap water were mixed with 50 liters of fish pond water. The fractional amounts of elements in the growth nutrient solution were adjusted to standard concentrations of elements in the hydroponic culture using common fertilizers. During the growth period and at the end of the experiment, the growth, morphological, and growth characteristics of the tomato plants were measured and examined until the fifth cluster harvest.

The results of this experiment showed that the Resh nutrient solution and modified fish pond water had the highest plant height, leaf number, and stem diameter compared to fish pond water alone. The results of the interaction between nutrient solution and tomato cultivars indicated that the longest distance from the planting medium to the first inflorescence was observed in the AZ5 cultivar with fish pond water, and the shortest distance was observed in the V4 cultivar with modified fish pond water. It seems that the increased uptake of nutrients such as nitrogen, potassium, and phosphorus in the growth nutrient solution and modified fish pond water treatments led to an increase in plant height, leaf area, stem diameter, and node number, while the insufficient availability of these nutrients in fish pond water treatment resulted in a decrease in growth indices. Based on the results, it was found that fish pond water had the longest days to the formation of the third fruit cluster (82 days), and modified fish pond water and Resh nutrient solution had the shortest days to the formation of the third fruit cluster (74 days). Furthermore, the Resh nutrient solution and modified fish pond water had the highest total fruit weight (480.84 and 456.00 g, respectively) and fruit diameter (6.25 and 5.99 cm, respectively) in the second cluster. Fish pond water had the lowest total fruit weight (247.89g) and fruit diameter (5.33 cm) in the second cluster. The results showed that the V4 cultivar had the highest total fruit weight in the second cluster with a mean of 425 g. The AZ4 and AZ5 cultivars had the lowest total fruit weight with 380 and 375 g, respectively. According to the comparison of means, the modified fish pond water and Resh nutrient solution treatments had the highest total fruit weight (477.93 and 456.49 g, respectively), fruit volume (107.47 and 98.15 cubic cm3, respectively), fruit length (5.66 and 5.11 cm, respectively), and fruit diameter (6.38 and 6.19 cm, respectively) in the third cluster. Fish pond water had the lowest total fruit weight (257.18 g), fruit volume (78.24 cm3), fruit length (4.84 cm), and fruit diameter (5.69 cm) in the third cluster. Previous studies have shown that increasing the concentration of nutrients in fish pond water, including magnesium, calcium, potassium, and even nitrogen, leads to increased fruit production and yield in mature plants under the influence of fish pond water salts. Therefore, the use of fish pond water and the modification of its nutrients with conventional fertilizers not only reduce the consumption of fertilizers and water in the agricultural sector, but can also play an effective role in reducing environmental risks and improving the level of sustainable agriculture.

The results of this experiment showed that modifying fish pond water probably improves the growth and yield indices of tomato fruit, possibly due to the adequate supply of required nutrients to the plant, similar to the standard Resh nutrient solution. The results showed that using modified fish pond water not only did not reduce the yield but also could increase the crop yield compared to fish pond water treatment. Additionally, the V4 cultivar had a more desirable performance in terms of yield and growth indices compared to other cultivars studied. Therefore, based on the results of this study, the promising V4 line is recommended for greenhouse cultivation using modified fish pond water.

Crop modeling is a widely used method for simulating the crop yield under different irrigation managements. Due that, in the study, a water-driven crop model, AquaCrop, was used to simulate and determine the optimal irrigation quantity and interval in Dehkhoda Sugarcane Cultivation and Industry Group (DH) farms. The data were collected from DH farms during 2019-2021. The total area under study was 230 hectares. The evaluation results showed that the AquaCrop model had an acceptable error for simulating yield (RMSE<5.6 ton ha-1) and water productivity (RMSE<2.2 kg m-3). In addition, the results of favorable efficiency (d>0.99), excellent accuracy (NRMSE<0.1) and high determination of coefficient (R2>0.94) showed that the simulation results of AquaCrop can be trusted. For this reason, 21 irrigation scenarios were simulated using the AquaCrop model in order to obtain the most appropriate irrigation amount and interval. Based on the results, close-end furrow irrigation with interval of seven days and the amount of 33000 m3 ha-1 was determined as a suitable option in terms of yield (132 ton ha-1) and water productivity (4 kg m-3). However, this scenario is for normal water conditions and if water stress conditions are created; a maximum of nine days for irrigation interval and at least 21000 m3 ha-1 is a better option for implementation in DH farms.

Currently, about 90 percent of the population of developing countries live in arid and semi-arid areas. Therefore, it is necessary and inevitable to identify the key and effective factors on the growth of agricultural products . The purpose of this research is to evaluate the accuracy and efficiency of the latest version of the AquaCrop model for simulating seed yield, biomass and water productivity efficiency of safflower in the form of a randomized complete block design with one control treatment (Conventional irrigation) and four deficit -irrigation treatments, including (RDI80, RDI60: reduced irrigation adjusted by supplying 80 and 60% of soil moisture deficiency) and (PRD80, PRD60: fixed partial root-zone drying irrigation with supply of 80 and 60% of soil moisture deficiency) and with four repetitions in Khuzestan University of Agriculture and Natural Resources was conducted. In order to evaluate the reliability of the model, some statistical indicator including the average normalized root mean Square error (NRMSE), the Coefficient of Residual Moss (CRM), Coefficient of Determination (CD), maximum error percentage (ME), Wilmot index (d) and the modeling efficiency (EF) was used. The statistical index (NRMSE) was obtained for seed yield (4.14), biological yield (10.16) and water productivity efficiency (4.9) and showed that the accuracy of the model in simulation is excellent. The results of the model validation show the accuracy and efficiency of the model in simulating seed yield, biomass and water productivity efficiency, and therefore, this model can be used to manage safflower irrigation in different states of deficit irrigation.

The crop water stress index based on canopy–air temperature differences (CWSIdT) is an appropriate index for monitoring the water status of croplands but is rarely used to evaluate the water status of forest ecosystems. However, CWSIdT is rarely used in forest ecosystems. Investigating the possibility of using the crop water stress index (CWSI) for planning the irrigation of four species of pasture trees, Prosopis cineraria (T1), Conocarpus (T2), Albezia lebbek (T3) and Ziziphus (T4), under four methods of surface irrigation, bubbler, pitcher, and waterboxx system, was selected. This research was conducted in the year 2021 in the experimental farm of the Faculty of Water and Environmental Engineering of Shahid Chamran University of Ahvaz and lasted for 9 months. The experiment was conducted as a factorial in the form of a randomized complete block design with 3 replications. The crown temperature, actual evaporation and transpiration and meteorological factors of the field were continuously and simultaneously measured during the period from the beginning of April to the end of December. Infrared thermometers was used to measure crown temperature and vapor pressure deficiency values for different irrigation treatments. The results showed that under well-watered conditions, canopy-air temperature difference and canopy surface transpiration rate are both controlled by the net radiation received by the canopy surface The highest and lowest calculated CWSI values were related to waterboxx and Pitcher irrigation with values of 1.01 and 0.81, respectively, which were related to Ziziphus and Konocarpus trees. Statistical analysis showed that the effect of irrigation method on plant water stress index values in spring and autumn seasons was significant at the level of 5% and the average values of plant water stress index increased with water consumption reductions of 87 and 59% in waterbox and pitcher irrigation systems, respectively. However, there was no significant difference observed in the summer season. Also, the effect of tree type on the CWSIdT index during the period was important at a 1% level. In addition, the difference in vegetation and air temperature were used as a determining factor to determine irrigation time, which can be used to estimate pasture tree water stress.

Estimating crop evapotranspiration (ETc) in arid and semi-arid areas can be difficult due to the dynamic nature of this process across both time and space. In addition, obtaining on-site measurements for this variable can be very time-consuming and costly. This study aimed to develop a framework that accurately estimates the sugarcane crop evapotranspiration on a spatio-temporal scale. This was achieved using four machine learning (ML) algorithms (MLR, CART, SVR, and GBRT) combined with remote sensing (RS) data and meteorological variables. Also, to reduce the dependence on several meteorological parameters in conventional ETc equations, the performance of eight different experimental temperature-based methods and four modified Hargreaves & Samani equations was evaluated compared to the standard FAO-Penman-Monteith method. For this purpose, weather data were collected from Hakim Farabi Sugarcane Agro-Industrial meteorological station for three years (2018-2021). Nine combinations of input variables (RS data and meteorological variables) were designed based on the IGR method and then evaluated by the ML algorithms. The results showed that the highest accuracy of ML algorithms based on R2, RMSE, and MAE statistics was obtained in CART (0.99, 0.41, and 0.18) and GBRT algorithms (0.99, 0.65, and 0.26), respectively. Regarding temperature-based methods, Ivanov’s equation had the best performance with an R2 of 0.91, while Baier and Robertson’s equation had the weakest performance with an R2 of 0.78 when estimating ETc. Overall, the combination of RS and ML algorithms effectively produced more precise and reliable ETc values on both temporal and spatial scales.

Due to the increasing growth of population and changes in lifestyle, the pressure on water and soil resources has increased, thus, proper management of these resources has vital importance. This research was conducted with the aim of evaluating and comparing the effects of furrow, surface, and subsurface drip irrigation on water productivity, yield, and yield components of spinach in arid and semi-arid climatic conditions of Ahvaz. For this purpose, an experiment in the form of randomized complete blocks with three treatments of irrigation methods including furrow irrigation (FI), surface drip irrigation (SDI) and subsurface drip irrigation (SSDI) was done in three replications in the research farm of the Faculty of Water and Environmental Engineering, Shahid Chamran University, Ahvaz, in 2021. According to the results, the amount of irrigation water used in the FI treatment was 1066 m3/ha and in the SDI and SSDI it was 787 m3/ha, which showed a decrease of 26.17%. In FI, SDI, and SSDI, the average yield of spinach plant (total fresh weight of leaves and stems) was equal to 23.56, 30.17 and 19.28 g and irrigation water productivity was 0.353, 0.613 and 0.392 kg/m3, respectively. In both yield and irrigation water productivity, the SDI treatment had a significant advantage at 5% level compared to the other two treatments. The effects of irrigation treatment on the characteristics of root length, stem length, total length, number of leaves, number of fresh leaves, leaf chlorophyll content and harvest index were not significant. Generally, considering water productivity as criterion, surface drip irrigation is more suitable than furrow irrigation for spinach cultivation.

In recent years, the use of SWAT model has been used as a common tool for simulating flow rate, sediment production and evaluating different scenarios to reduce sediment production and runoff. The current research also aims to evaluate the changes in runoff and sediment under the influence of irrigation water reduction, using the SWAT model in the irrigation and drainage network of Dez River.

Recalibration and validation of the model for simulating runoff (Shoshtar, Arab Asad, Shavor Bridge, Harmeleh and Bamdej stations) and sedimentation (Shoshtar, Shavor Bridge, Harmaleh and Bamdezh stations) using statistical data from 1995 to 2012 and 2013 It was done until 2017. The simulation results were also evaluated using R2 and NSE coefficients. Then the scenarios of 10, 20 and 30% reduction of irrigation water were introduced to the model to evaluate their effect on runoff and sedimentation of the study area.

The results of model evaluation using R2 and NSE coefficients indicate the appropriate performance of the model in simulating the mentioned parameters. The results of the evaluation of scenarios of 10, 20 and 30 percent reduction of irrigation water show that applying the 10 percent scenario had the least impact on the amount of sedimentation. On the other hand, applying the scenario of 30% reduction of irrigation water will increase the runoff (30-60%) due to the reduction of the collection of runoffs for irrigation purposes and consequently the increase of the amount of sediment (20-50%) in the irrigation and drainage network of Dez River. The obtained results indicate that the increase in the amount of runoff in the basin, especially in the rainy season, has caused an increase in erosion and consequently an increase in sediment in the basin. Therefore, it can be stated that the time of applying the scenario and the characteristics of the soil in the area are the most effective components on the amount of runoff and sediment in the basin.

According to the results obtained, according to the effect of runoff on erosion and the amount of sediment in a watershed, it is necessary to use methods to control and reduce runoff, such as watershed operations, structures to contain and store runoff, and use modern irrigation methods to prevent soil erosion. Because traditional irrigation methods, in addition to water losses, cause a decrease in soil fertility and an increase in sediment in the drains of agricultural lands. In lands that are irrigated by traditional methods, sometimes the amount of water used is more than the infiltration capacity of the soil. This causes erosion of the surface layer of the soil by the runoff from water accumulation. Therefore, agricultural management approaches in basins prone to soil erosion should be focused on modern irrigation methods with minimum runoff and drainage output.

Aloe vera L. is one of the medicinal and perennial plants, which is cultivated in arid and semi-arid regions. Although this plant is relatively resistant to lack of irrigation, but in the conditions of commercial cultivation, it is necessary to pay attention to the supply of irrigation water during the growing season. Due to that, the present study was conducted in order to investigate the effect of the amount of irrigation water (I1: 50, I2: 75 and I3: 100% of water requirement) and Trava 2020 superabsorbent (A1: zero, A2: 5 and A3: 10 grams per kilogram soil) on the yield and yield components of Aloe vera. These treatments were applied in three replications and the crop was harvested in two times include: autumn 2020 and spring 20201. The experiment was carried out in a research farm in Omidiye city with longitude 30°37’ and latitude 49°49’. Leaf length, leaf width, leaf weight, number of leaves and number of offset in the second harvest were 26.8%, 25.1%, 25.5%, 27.0%, 24.1% and 17.5% more than the first harvest. Increasing the consumption of superabsorbent caused an increase in leaf length. The difference between the leaf length in two treatments A3 and A2 was about 3.4% and between two treatments A3 and A1 was about 6.9%. With the increase of superabsorbent consumption, the leaf width increased so that its value reached from 79 mm in A1 treatment to 83 mm in A3 treatment.

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).

Spatiotemporal estimation and monitoring of soil moisture based on remote sensing observations (optical and thermal) is challenging due to its physical nature in high vegetation conditions, necessitating improving and increasing the accuracy of soil moisture estimation in these areas. Therefore, this research aimed to develop a new approach to estimating surface soil moisture in agricultural fields with dense vegetation using machine learning algorithms by incorporating optical and thermal remote sensing data and soil physical properties. For this objective, 16 Landsat-8 satellite images and more than 430 control locations were used during the sugarcane crop’s growth period in 2018-2019 at the Hakim Farabi Sugarcane Agro-Industrial company in the Khuzestan province of Iran. A set of 10 scenarios of various unique combinations of the available input variables were developed and then evaluated by five machine learning algorithms, including multiple linear regression (MLR), decision tree-based algorithms (CART and M5P), and ensemble learning-based algorithms (gradient-boosted regression trees (GBRT) and random forest regression (RFR)). According to the results, the highest correlation between input variables and surface soil moisture was observed in Soil Wetness Index (SWI) and Normalized Soil Moisture Index (NSMI) with R values of 0.79 and 0.69, respectively. Also, the highest accuracy of machine learning algorithms based on R2, RMSE, and MAE results was obtained in GBRT (0.99, 0.011, and 0.006) and RFR (0.99, 0.014, and 0.007), respectively. In general, the findings of this research show the importance of using variables based on Landsat-8 remote sensing data in combination with ensemble learning algorithms that can be independent of any ground measurements.

Hydraulic conductivity is one of the most important physical properties of soil, and knowing it plays a vital role in investigating the transport of solutes and pollutants in porous environments such as soil. This study aims to obtain saturated hydraulic conductivity pedotransfer functions (PTFs) using soil properties and satellite images. In this regard, the hydraulic conductivity of soil saturation was performed using the Inversed augerhole method in a part of the southwestern lands of Khuzestan province at 50 points. Then, at these points, surface samples of the soil were taken and soil properties such as soil texture, electrical conductivity, soil organic carbon, and saturated moisture were determined in the laboratory. In the next step, the indices of Sentinel-2 satellite images were calculated in three categories of soil, vegetation, and moisture indices and 11 PTFs, (PTF1-PTF11) for saturated hydraulic conductivity were obtained in four stages by combining soil properties and these indices. Finally, the spatial distribution of saturated soil hydraulic conductivity was obtained using the random forest model. The results of the modeling of PTFs of saturated hydraulic conductivity showed that among the 11 models with which PTFs of hydraulic conductivity were performed, the combination of three vegetation indices with soil-found early properties was the most effective for estimating the saturated hydraulic conductivity (PTF7). The values of R2, RMSE and MAE for this case were equal to 0.83, 0.40 and 0.166 respectively. Finally, the spatial distribution of saturated hydraulic conductivity using the Random Forest model showed that this model performs the spatial distribution of saturated soil hydraulic conductivity of soil well. Based on the obtained results, it can be found that the combination of soil properties with the indices obtained from the Sentinel-2 satellite images, creates PTFs of saturated hydraulic conductivity of the soil with very high accuracy.

Safflower (Carthamus tinctorius L.) is a multipurpose crop that is widely grown in arid and semi-arid regions of the world, mainly to produce high-quality edible oil rich in unsaturated fatty acids. The objective of this study is to investigate the effects of regulated deficit irrigation (RDI) and partial root zone drying (PRD) methods on yield, yield components and water productivity efficiency of safflower. This study was conducted in the Experimental Research Station located in Agricultural and Natural Resources Sciences University of Khuzestan during the 2020 to 2021 and 2021 to 2022 growing seasons. The experiment was designed as a completely randomized block with one control treatment (Conventional irrigation) and 4 deficit irrigation treatments and in four replications. The results showed that the different irrigation methods had a significant and decreasing effect on plant height, number of seeds per plant, thousand seed weight, seed yield, biological yield and oil yield traits. Comparing RDI80 and PRD80 treatments, the highest seed yield (3.4 tons/ha) and oil yield (845.7 kg/ha) and the highest value of water productivity index was obtained from RDI80 treatment. Also, comparing RDI60 and PRD60 treatments, the highest seed yield (2.2 tons/ha) and oil yield (584 kg/ha) was obtained from PRD60 treatment. Therefore, according to the obtained results, it is recommended to use the RDI80 regulated deficit irrigation method to reduce 20% and the PRD60 partial root zone drying method to save 40% of water requirement for safflower cultivation in hot and dry areas with limited water resources.

This study examined the feasibility of using zeolite clinoptilolite to filter nitrate, phosphate pollutants and salt from the agricultural drainage water. To that end, significant pollutant absorption parameters, such as adsorbent particle size, pollutant concentration, salinity, temperature, retention time, pH, and adsorbent concentration were optimized in the batch condition. Having optimized the parameters, the researchers conducted adsorption experiments on an experimental model, similar to the subsurface drainage systems applied in farms. Adsorption experiments were carried out at the optimized parameter levels on four models, namely a reference model (D0), a model with adsorbents around the drains (D1), a model with adsorbents around the plant roots (D2), and a model with adsorbents on the soil surface (D3). These models were fed with untreated drainage water from the farms in the south of Khuzestan during the fertilization season. The results showed 63 percent nitrate removal efficiency, 39 percent phosphate removal efficiency and 79 percent salt removal efficiency by using 30 g.L-1 of 1000 µm adsorbent particles for a pH of 5, initial pollutant concentration of 80 mg.L-1 nitrate and 10 mg.L-1 phosphate in 12 dS/m salinity during a 90-minute retention time period at 50 °C ambient temperature. These parameter levels led to nitrate, phosphate, and salt removal efficiencies of 59.72 percent, 29.28 percent, and 77.47 percent respectively, in the model with clinoptilolite adsorbents around the drains (D1).

The  amount  of water  and  fertilizers  used in  the  production  of vegetables,  specifically  tomatoes,  is  high. This experiment was carried out to investigative of effects of yield, nutrient solution efficiency,Vegetative growth, and stomatal gas exchanges of two greenhouse tomato cultivars (V4-22, Amira) in open and closed hydroponic systems, as split-plot design based on completely randomized block design with three 3 replications at Shahid Chamran University of Ahvaz. The results showed that the effect of the hydroponic system had a significant effect on the efficiency rate of nutrient solution usage, fruit length, fruit firmness, leaf area, plant height, stomatal conductance and leaf temperature (P≤%5). The highest fruit length, fruit firmness, leaf area, plant height, stomatal conductance, and leaf temperature were measured in the open hydroponic system. The water productivity per performance in closed hydroponic system was greater than (approximately 55%) open hydroponic system. The highest and lowest water productivity biomass were obtained in the closed system and open system (48.91 and 34.42 kg/m3), respectively. The highest and lowest crop yields were measured in V4-22 and Amira cultivar (3874.29 and 3648.70 g per plant), respectively. Based on the results, the open hydroponic system has increased the characteristics such as plant height, leaf area, number of leaves and stomatal conductance, but the performance of the product in these two hydroponic systems is not different and also the closed hydroponic system reduces nutrient solution consumption up to 96% and fertilizer consumption up to 97%.

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.

Multi-criteria decision making (MCDM) and Geographic Information System (GIS) for accurate decision making about the evaluation parameters used in natural sciences. This selection is influenced by different factors such as production and irrigation system expenses, water availability and quality, soil characteristics, climate conditions, labor skills, and cultural acceptability. The present study was conducted over an area of approximately 11081 ha in the Izeh plain Khuzestan province, south west Iran during 2015-2016. Results of the comparison (for each factors pair) were described in term of integer values from 1 (equal value) to 9 (extreme different) where higher number means the chosen factor is considered more important in greater degree than other factor being compared with. Analytic Hierarchy Process (AHP) is one of Multi Criteria decision making method that was originally developed by Prof. Thomas L. Saaty. In short, it is a method to derive ratio scales from paired comparisons.. The AHP was used for optimization.Spatial analysis to identify susceptible regions for pressurized irrigation systems starts with representing each selected physical sub-criterion by a thematic layer in which each point takes a value (1 to 9) which the samples have been gathered in a laboratory or a qualification according to that criterion. In order to layer all the criteria, data are gathered from satellite images and official sources at different available forms (digital and hard copy maps, tables and charts). Then, they are analyzed and treated using GIS and geostatistical tools. Each layer is obtained in raster data model. Spatial data on water characteristics, topography and climate (temperature map) are obtained from “water and power authority’’ of Khuzestan district, which is the Iranian official source of agricultural spatial database. Data are already available in digital format with 1/150,000 scale.

Major advantage of AHP is to formalize and renders systematic what is largely a subjective decision process and as a result facilitates ‘accurate’ judgments, that weights of criteria are also provided to decision maker, and that sensitivity analysis is easy to conduct by using computer. The weights of each criterion were computed by using the geometric mean to obtain the weight values. After that the weights should be aggregated and each weight divides on aggregated weights in order to normalize the weights. The normalized weights determine the priority of criteria. The sum of all normalized weights in each Table is equal to unity. The AHP methodology says that prioritizing and weighting the criterions should be done firstly. According to fundamental Saaty 's scale for the comparative judgments and by performing pair - wise comparisons of criteria with respect to the object, here the comparison and calculation of criteria in 1st , 2nd and 3rd levels in general for Localize irrigation system as an example. Most large drip irrigation systems employ some type of filter to prevent clogging of the small emitter flow path by small waterborne particles. New technologies are now being offered that minimize clogging. Considering conditions of water used for irrigation in the study region, suspended materials (W sm) and biological materials (W bm) were seen in the water according to laboratory experiments. Filters were employed in the farm and the water is available in the farm by pumping it from wells, but filters need to be changed after a while so possibility of clogging in the drippers still exists, therefore, these two alternatives have higher weight than available water. The amount of Sodium concentration (W na) was low and has less importance than other criteria except available water. Localized irrigation systems designed for no leaching fraction. High electrical conductivity (EC) and salts applied with the irrigation water may build up in the root zone but EC of the study region is almost low. Alkaline water (refers to pH) could make sediments in the drippers

In this study surface irrigation system found to be the best systems for this region. The comparisons expose that the results from the proposed model are in good agreements with results from the field investigations. An additional benefit of the model is that the decision-maker can perform a more exhaustive conceptual comparison of the different decision components. Causing that an extensive set of factors involved in selecting an irrigation system has been included in the proposed model, it can be claimed to be a comprehensive and practical model that can be used in selecting the irrigation methods for various agricultural sites, thereby improving soil and water resources exploitation and productivity.

Deficit irrigation is the strategy used to produce a crop with maximum income and profits. This method has attracted attentions due to the intensification of the water crisis and population growth. Basinger and Hellman (2006) suggested that deficit irrigation increases the water use efficiency by 72%, but it has little effect on reducing the amount of the product. Negaz et al. (2013) experimented the efficiency of optimum water use of lettuce, in different irrigation regimes (30, 60 and 100% of plant water requirement), in Tunisia. The results showed that the highest water use efficiency was related to 30% water requirement and the lowest was 100% water requirement with 34.3 and 14 kg/m3, respectively. Haghighi (2008) compared the PRD (Partial root zone drying) irrigation method and conventional irrigation on greenhouse tomato growth and concluded that PRD treatment increased the water use efficiency of the plant and increased the total soluble solids. While, no significant difference was observed between the two treatments in the number of fruit, color and fresh and dry weight of root. On the contrary, PRD reduced the dry weight of the shoot and the weight of the fruit. Also, the rate of handling and distribution of red fruit was higher in PRD treatment. This study were investigated the effect of regulated deficit irrigation (RDI) and PRD on tomato, under hydroponic culture conditions. The treatments of experiment consisted of five treatments: RDI irrigation at 85 and 70% of plant water requirement and PRD irrigation at 85 and 70% of the plant water requirement, and control treatment. The experiments were carried out in a completely randomized design with four replications. The water requirement of the plant was determined by the evaporation rate from class A evaporation pan (located in the greenhouse) and multiplying it at the plant shadow level. To feed the plants, Resh nutrient solution (2005), which contains macro and micro nutrients for plant growth, was used. For preparing of solution, urban drinking water was used with EC=1.8 mS/cm. The leaf area was measured every two weeks by a ruler. After applying the treatments, the greenhouse tomato product was manually harvested in 5 times. The number of harvested fruits only consisted of fruits that were fully grown and ready to be harvested. According, every 2 weeks, the fruits were counted, harvested and weighted. After the end of the growth period, the fresh and dry weight of root, fresh and dry weight of leaf, leaf water content, leaf area, fresh and dry weight of stem and biomass and dry weight of plant were measured. Also, leaf area index (LAI), special leaf area (SLA), leaf area ratio (LAR), harvest index, water use efficiency and efficiency of biomass water use were calculated. The results showed that different methods and levels of deficit irrigation had significant effects on fresh and dry weight of root, fresh and dry weight of stem, plant dry weight, fruit weight and water use efficiency. But, the levels of applied water did not significantly affect fresh and dry weight of leaf, leaf water content, leaf area, leaf area index, special leaf area, leaf area ratio, biomass weight and harvest index. The results showed that the plant with irrigation application of 85% of plant water requirement showed different results in fruit weight index and water use efficiency, in comparison with the control treatment. Deficit irrigation of PRD treatment in the weight of fruit increased by 3.5% and water use efficiency increased to 22 percent, compared with control treatment (2572.5 g and 16.07 kg/m3, respectively). But, RDI treatment in fruit weight decreases by 20% and reduces water use efficiency by 5.5% compared with control treatment (1997.8 g and 12.48 kg/m3, respectively).With reducing applied water to 70% of plant water requirement, the behavior of the plant was different, and RDI treatment showed a lower reduction for the fruit weight index and water use efficiency than PRD treatment. Accordingly, the RDI treatment in fruit weight decreased by 35% and water use efficiency decreased by 7% (1614.2 g and 12.24 Kg/m3, respectively). While, PRD reduced 52% in fruit weight and decreased 31% of water use efficiency (1189.5 g and 9.02 Kg/m3, respectively). Eventually, PRD treatment with 85% of plant water requirement was selected as the best method for hydroponic culture of tomato in greenhouse.

The limitations of water resources and recent droughts have dictated to use modern crop production systems for reducing water application and increasing water productivity. This research was carried out in the integrated greenhouse of agricultural faculty of Shahid Chamran University of Ahvaz in 2016. This study has investigated the effects of regulated deficit irrigation (RDI) and partial root zone drying (PRD) on tomato under hydroponic culture conditions. This experiment was conducted in a completely randomized design with four replicates and five treatments, consisted of RDI at 85 and 70% of plant water requirement, PRD irrigation at 85 and 70% of the plant water requirement, and control. The results showed that the different methods and levels of deficit irrigation did not have a significant effect on calcium, magnesium, sodium, potassium, pH, TSS, organic matter and fruit diameter, while they have significant effect on the number of fruits, fruit weight, fruit height, and water productivity. The highest fruit weights per plant and water productivity were observed in PRD85 treatment and the least fruit weight per plant and water productivity were observed in PRD70 treatment. Also, deficit irrigation through PRD85 was selected as the best treatment for hydroponic cultivation of tomato.

Maize cultivation is considered as one of the main crops in the Khuzestan province. Mostly, in planning water requirement is calculated as a point, while irrigation is preformed locally. Therefore, this data must be converted from the spot to the region. In this research, in order to determination irrigation scheduling in Khuzestan province were planted spring Maize in lysimeter at the Faculty of Water Sciences Engineering of Shahid Chamran University of Ahvaz. The aim of this cultivation were compared between the current methods of determination of water requirement and lysimeteric method and determine the appropriate equation. The results showed that the Blaney-Criddle equation is the best method to estimation evapotranspiration in case study area. After determining the appropriate equation of water requirement, mention equation and meteorological data were used for zoning Maize water requirement with geostatistical methods.The zoning was performed using ARC GIS 10.3. First, the data were normalized. Then, according to the lowest RMSE were selected the best semi variogram and zoning model. The results show that simple kriging with circular semi circular model in all months is considered optimal model. RMSE value of this model was calculated, the amount of it was 0.08, 0.17, 0.46 and 0.48 for March, April, May and June. The result of water requirement zoning showed that this parameter in south is more than north of Khuzestan province. Also, the amount of water requirement in last months is more than first months. During the study period (from March to June), water requirement was 1.98, 5.52, 11.78 and 11.97 (mm/day) monthly. Small amounts of RMSE was indicated the optimum of water requirement zoning.

In order to evaluate using effluent (as sequential irrigation), a study was conducted at research farm at Shahid Chamran University of Ahvaz (located at latitude 31˚ 18’, longitude 48˚ 39’ and elevation 18m) during 2014-2015. Regarding to this purpose, a farm (with long 30m and width 24m) was selected and divided into 3 parts (A, B and C). Corn, soybean and sunflower were cultivated in parts A, B and C, respectively and effluent was used for irrigation of next parts. In part B, a split-plot design as randomized complete blocks with two treatments: irrigation type (Karun River and effluent) and urea fertilizer (100%, 75% and 50% application) was applied. Experiment design in part C was similar to part B except at 75% urea fertilizer. ANOVA results for soybean revealed that interaction between irrigation type and urea levels had significant effects on growth yield and biological water productivity (P

The aim of this study was to examine the possibility of reuse of wastewater of Shahrekordʼs sewage treatment plant for agriculture and determine the restrictions of use of wastewater in drip irrigation system in terms of influence on emitter clogging potential.
For this purpose, some of physical, chemical and biological parameters of wastewater quality of Shahrekordʼs sewage treatment plant, in April-September 2015, were measured on a monthly basis and then compared with the Iranian Environmental Protection Organization standards, World Health Organization standards (WHO), World Food and agricultural organization (FAO) and the standard of water quality classification according to the emitter clogging potential.
According to the results of water quality, the average amount of fecal and total coliforms in wastewater during the study, were 6416.8 and 16966.7 (MPN/100ml), respectively; that was outside of the recommended permissible range by the Iranian environmental protection organization standards for wastewater use in agriculture, so more chlorination is necessary, before wastewater discharge. In addition, based on the average value of microbiological parameters, fecal coliform and the number of intestinal nematodes (0 N/100ml) and according to World Health Organization standards, the use of wastewater for irrigation of plants that can be eaten raw, is not possible. Also according to FAO standard, wastewater application in terms of average amount of bicarbonate concentration in this period (4.64 me/L), had low to moderate limitation for crops. restriction Degree on use of wastewater in drip irrigation system in terms of average amount of total coliform count, level of pH (7.65) and water hardness (251.1 mg/L), was Moderate, and in the terms of average value of concentration of dissolved solids (405.5 mg/L), the concentration of suspended solids (35.2 mg/L), electrical conductivity (0.66 dS/m), iron (0.024 mg/L) and manganese (0.013 mg/L), was low. In addition, according to the negative value of langelier saturation index during the study period (-1.03), the possibility of sediment in the water, there weren’t.
According to the low potential of emitter clogging duo to physical and chemical agents, biological agents, considered as the main cause of emitter clogging when wastewater of Shahr-e kordʼs sewage treatment plant, use in drip irrigation systems. Thus, drip irrigation systems can be used in program of reuse of wastewater of sewage treatment plant in Shahr-e kord for irrigation of cereal and industrial crops resistant to high concentrations of bicarbonate and with consideration the use of managements such use of appropriate filter, acidification, flushing of laterals and especially chlorination of the irrigation system.

Water productivity is one of the indexes which is widely used in the issues related to crop productivity and water, and is defined as the ratio of the amount of crop yield to the amount of water consumed by the crop. The water consumed by the crop may be supplied by rain, Irrigation or even irrigation plus precipitation. In fact water productivity is an indicator of the amount of production for each unit of consumed water. In this study, the amount of annual water productivity was indicated according to the available information and six years data-set, and then the mean value was reported for network’s crop water productivity. In this practice, ten networks namely, Avan, Dez, Shavoor, Maroon, Fajr & Jaizan, Gotvand, Karkhe, Ramshir and Shadegan were studied. Water productivity of the networks was estimated according t o the crop yield and the volume of consumed water. The highest rates belonged to Avan, Gotvand and Shadegan, being 1.03, 0.98 and 0.85 Kg.m-3 while Ramshir with an average water productivity of about 0.44 Kg. m-3 had the least value. An analyze over the relationship between crop yield and irrigation shows that, wheat crop yield will increase until the time that the crop’s water requirement is supplied, but it does not change or even decreases when the amount of applied water goes beyond the crop’s water requirement, thus as a result, the water productivity decreases.

In order to evaluate the effect of different crop management methods and irrigation with saline water on evapotranspiration and water use efficiency of Maize, the factorial experiment with randomized complete block design was conducted. This project was carried out in the Agricultural farm of Shahid Chamran University of Ahvaz from March to June 2015. Different crop managements include without crop residues, use of crop residues on soil surface as mulch and mix of crop residues with surface soil layer to 30 cm depth and water irrigation salinity include water salinity of Karoun river (2dS/m), 4.5 and 7 dS/m. The results of variance analysis showed that the effect of salinity, crop management and their interaction effect on evapotranspiration, yield and water use efficiency was significant. Minimum values of ET (387.5mm) and WUE (0.68 kg/m3) were obtained at the salinity level of 7 dS/m. The management of residues use as mulch had the most effect on ET decrease (9%) and yield increase (10%) and So, the maximum WUE (1.10 kg/m3) was obtained at it too. The greatest impact of residues applications mulch and mixing with soil surface layer in increasing of yield (19% and 9% respectively) and WUE (27.6% and 10.6%, respectively) compared to non-use of residues was observed at the salinity level of 4.5 dS/m. Therefore, the use of crop residues particularly as mulch can be recommended as an effective way to reduce the damage of irrigation with saline water.