حیدرعلی کشکولی

To monitor and compare the changes of salts in the soil profile around the roots of the corn plant, the plant yield, and the productivity of corn water, an Experimental was conducted in a completely randomized block of three repetitions in two crop years 2017-2018 and 2018-2019 at Ahvaz Agricultural Research Station. Experimental treatments included two subsurface drip irrigation systems with a working depth of 30 cm from the soil surface and tape irrigation and two irrigation intervals of 2 and 4 days. The results of monitoring soil solutes obtained from sampling depths (0-25, 25-50, and 75-50 cm) showed that soil salinity in the second year in both systems as a result of improving the quality of irrigation water from 3.61 dS/m to 2.01 dS/m, it was reduced by two times. The results of soil salinity monitoring showed the highest ratio of salinity reduction with a 2-day irrigation interval in both irrigation systems. The most leaching was done at the irrigation depth of 25-50 cm in the subsurface drip irrigation system and at the depth of 0-25 cm in the tape system. The highest yield of corn dry fodder was 9.13 and 7.13 tons per hectare, respectively, and the best water efficiency based on dry corn fodder at the rate of 13.74 kg/m was obtained in the strip drip irrigation system (tape) with a two-day irrigation interval and in the second crop year. Also, the results of the soil salinity measurement showed that the implementation and exploitation of the drip irrigation system can be the basis for improving the quality of the soil as the most important non-renewable resource of agriculture.

In order to investigate the effect of drought stress on yield and yield components of four bread wheat cultivars, an experiment was conducted in the form of split plots based on randomized complete blocks in three replications at Sanandaj Grizzah Agricultural Research Station. In this experiment, irrigation cessation as the main treatment at four levels, including cessation of irrigation in the spike stage, cessation of irrigation in the flowering stage, cessation of irrigation in the milking stage and normal irrigation, and bread wheat cultivars as a sub-treatment in four levels, including Sions were Gascogen, Zarrin and Alvand. The results of this study showed that irrigation cut-off treatment led to a significant reduction in traits such as spike length, 1000-seed weight and grain yield, but traits such as number of seeds per spike, number of spikelets per spike and number of seeds per spike were not significant. The results also showed that Alvand and Zarrin cultivars were the most resistant cultivars to different levels of stress, respectively. In addition, normal irrigation had the best results in increasing the yield and yield components of bread wheat cultivars.

Drip irrigation delivers moisture to the soil surrounding the plant root, leaving the uncultivated ridges mostly dry. The dynamics of dryness and moisture can help adjust the soil salinity and redistribute moisture and salinity (Li et al., 2013; Wang et al., 2011). Further, the distribution of soil salinity in arid regions is affected by a multitude of factors, including the water table (Ming et al., 2016), groundwater salinity, (Abliz et al., 2016), irrigation system (Lie et al.,2013;Zhang et al.,2017), and soil texture (Hu et al., 2011; Zhang et al., 2014). Given the complexity of investigating moisture and salinity distribution in the soil and their uptake by plant roots, the subject has been addressed by several studies around the world. The present study attempts to investigate and evaluate the effects of different irrigation regimes (two-, three-, and four-day) using a tape drip irrigation system on the diffusion and distribution of salinity and moisture around the root of summer maize over two crop years (2018–19) in the South Khuzestan region, where a heavy soil texture is predominant.

Located between the 29°57’ N and 33°0’ N relative to the equator, and between 47°40’ E and 50°33’ E relative to the prime meridian, Khuzestan Province occupies 64,057 square kilometers in Southwest Iran. The present study was carried out in a research farm at the Center for Agriculture and Natural Resources Research and Training, Ahwaz, Khuzestan Province, in summers 2018 and 2019. With clay and silty clay soil textures, shallow and saline groundwater (1.5 m depth), and its particular climate, this research farm can be representative of the farmlands of Central and Southern Khuzestan. The required volume of water during each irrigation by the drip tape irrigation system under different irrigation regimes (two-, three-, and four-day) was calculated for different plant development stages and treatments, thus enabling control over the different irrigation hours in different regimes. the farm soil was sampled at four stages, namely before planting, upon germination, during the middle development stage, and after planting), for physical and chemical characterization and monitoring salt levels from three depths (0–25, 25–50, and 50–75 cm) at a 20 cm distance from the tape by manual excavation using an auger (10 cm in diameter and 20 cm in length). Soil salinity and other quality criteria were measured in the lab. Further, the SMC was measured by the weight percent method, which involves weighing and drying the samples.

The present study addressed moisture and salinity distribution in the soil profile around the plant root under different irrigation regimes. The moisture distribution results showed that all irrigation regimes (two-, three-, and four-day) could maintain the moisture around the FC, slowing down the vertical flow and minimizing penetration into depths. The soil salinity results showed that, considering the soil salinity conditions at the start of the growing season, using the drip tape irrigation first reduced and then increased salinity in the first year of cropping. In contrast, in the second growing season, soil salinity at the end of the growing season using two-, three-, and four-day irrigation regimes was cut to a fourth and a third of its initial level. This shift in the behavior was, however, due to the differences in the quality of irrigation water. This outcome shows the susceptibility of using the drip tape irrigation system in soils that are prone to sodicization and salinity, which requires preparing the conditions to ensure the sustainable function of the irrigation system. The final set of samples showed that, under all irrigation regimes, the emitter output effectively reduced soil salinity, and that this reduction is more effective with frequent irrigations, washing the salts further away from the source. Further, the 0–25 cm deep layer was found to have the least salinity among the studied layers. All irrigation regimes (two-, three-, and four-day) were successful in controlling salinity in the root zone, but the two-day treatment, with a shallower irrigation depth and shorter irrigation intervals, offered the best leaching. The results of performance analysis in two years showed that the year did not have a significant effect on grain and dry matter yield. The results also showed that irrigation regimes did not have a significant effect on dry matter yield but significant on grain yield at 5%.

The present study was conducted to evaluate the efficiency of the HYDRUS model in simulating soil water movement and redistribution of moisture around the roots of maize in homogeneous and heavy soils. This study was carried out in the Agricultural Research Center of Khuzestan Province under drip strip irrigation with three irrigation regimes of 2, 3 and 4 days with three replications during two cropping years. In order to monitor the moisture around the roots, dig a soil profile to a depth of 75 cm perpendicular to the drip irrigation strip. Observed and simulated moisture values were compared byR2,EF, MAE and RMSE statistics. The results showed that the average moisture distribution in each irrigation regime is in the range of crop capacity. RMSE values for different diets ranged from 1.29 to 2.40% and MAE values for different diets ranged from 1 to 2%. Moisture simulations were classified as excellent based on MAE and RMSE values.Also, the results of the coefficient of explanation are between 60 to 90% and the efficiency of the model is between 40 to 90%. Based on the results, the lowest efficiency of the model was in the simulation 24 hours after irrigation and the best simulation was 72 hours after irrigation. The results show the high capability of the model in simulating soil volumetric moisture.

In the new drainage conditions in the center and southwest of Khuzestan Province, by reducing the depth of drainage installation and controlled drainage, studying the dynamics of the mixing zone, understanding the specifications of this region, and its effect on the flow rate of drainage water and salinity is important. In this study, seven groups of piezometers, each consisting of 8 piezometers placed at different soil depths (0.8 to 5m) and at different distances from the drainage water collector were studied in two research farms, namely, field R9-11 Dabal Khazaei agro-industry (with an average drainage depth of 2 m and distances of 65 m) and field R8-7 in Salman Farsi agro-industry (with an average depth of 1.4 meters and 42 meters distances).Water level in piezometers, water salinity in different soil layers, and drainage water flow rate and salinity were monitored daily in three periods of heavy irrigation of sugarcane (March to October of 2013, 2014 and 2017). Results indicated that by starting a heavy irrigation, hydraulic head increased and hydraulic head variance between bottom layer (4 and 5 m) relative to the surface layers, established vertical flow and saline inflow upwards. Reducing the installation depth of drains up to 60 cm from in R9-11 compared to farm R8-7 and moving away from the collector up to 400 m in each farm, reduced the installation depth of drains up to 40 cm, and increased the hydraulic load by an average of 8-12 cm. The thickness of the mixing area was up to one meter and the reduction of the average salinity line in the mixing area was 8%. It was found that in addition to irrigation water salinity, drainage water salinity was affected by groundwater salinity and the difference in drainage depth, position of the impermeable layer, and the presence of sand lenses. By decreasing drainage depth, the drainage water discharge decreased sharply, such that the averag drainage water from each lateral in farm R9-11 was 10 mm/day, and in farm R8-7 it was 3.3 mm/day. The results showed that with increasing the thickness of the salt and fresh water mixing zone due to the optimal reduction of drainage depth, the volume of water consumed in each irrigation cycle decreased due to plant use of this zone, which can be an effective factor in conserving soil and water resources.

Water deficit is known as the most important limiting factor in agricultural products, especially in the arid and semi-arid regions. Agriculture has been negatively influenced by low obtainable water and because of climate change, making water stress conditions for economic crucial plants. As Iran's major region is consisting of the arid and semi-arid areas with limited water resources, in case of the minimum plant water use is not maintained, the plant would experience drought stress and the products would suffer irreparable losses. One way for optimal use of the water resources and their preservation is the use of superabsorbent polymers which not only provide conditions for improved products quality but also results in increased water consumption efficiency in the arid and semi-arid areas. Superabsorbent polymers could absorb and retain water up to several times of their weight. Due to the drying up of the environment, the water retained in the superabsorbent will gradually discharge, and thus the soil would remain moist for a long time, without needing further irrigation. This property is the great importance to confront water shortage and reduce the harmful effects of drought stress in plantations. Superabsorbent polymers cause water retention in the soil and reduce the number of irrigation frequency up to 50%.

In this study, the effect of water stress and different levels of superabsorbent on cucumber crop (variety of super dominus hybrid) in a farm with sandy soil, in Seymareh region, Ilam province, Iran was evaluated. This experimental farm was conducted at 33° 09′ N and 47° 24′ E, and with an elevation of 982 m. Seymareh region has a Mediterranean summer and winter. The average annual precipitation is about 350 mm and the average temperature is about -2° C in the winter and about 45° Celsius degrees in the summer. The hydrophilic polymer: Super-AB-A-300 used in this study. This polymer is a granular type and produced by Rahab Resin Co. with product license holding of Iran Polymer and Petrochemical Institute. This hydrophilic polymer is a terpolymer of acrylamide, acrylic acid, and acrylate potassium. The experimental design was according to a split-plot method in a randomized complete block design that was done with 12 treatments and 3 replications. In this study, 3 different depths of irrigation were considered as the main treatment including I1, I2, I3 as 100, 80 and 60 percent of water requirement of plant respectively and different levels of superabsorbent were used as secondary treatment including S0, S1, S2 and S3, equal to 0 (control), 15, 30 and 45 g m-2 respectively. The size of each plot was 4 * 1.2 m2 including 6 lines. The Superabsorbent for each line in each plot was distributed in a depth of 30 cm from the soil surface. The cucumber variety of this plan was planted manually in April as spring planting and in August as summer planting. The space between planting rows was 20 cm, and between each plant in each line was 40 cm, so a total density of planting was 60 plants per each plot. Three grains were planted at each point which after germination, they were thinned out to one plant. From the 3 to 4 leaf stage (after the complete establishment of the seedling) the deficit irrigation treatment was applied. For planning and determining the irrigation interval, by adopting the no water stress treatment as the criterion, the soil moisture index and the soil matric potential were incorporated. The percentage of soil moisture content was measured through sampling to the depth of plant root in the days before irrigation and when the weighted mean of the volumetric soil moisture reached the allowable depletion for the cucumber plant, the next irrigation was performed; therefore, the irrigation interval was determined; concerning the treatment with no water stress (control) and simultaneously all the treatment plans with equal irrigation intervals and with different water depths were irrigated.

According to the results, the independent effect of irrigation and superabsorbent treatments at 1 percent level on cucumber crop yield was significant. The maximum and the minimum of cucumber fruit weight and crop yields were 72.86 and 56.90 g, and 3.7 and 1.97 kg m-2 related to the complete irrigation (I1) and severe drought stress (I3) respectively. Results showed that in the drought conditions, superabsorbent application increased cucumber fruit weight and crop yield compared to control treatment. Also, the independent effect of irrigation and superabsorbent treatments at 1 percent level on water use efficiency of cucumber crop was significant. The maximum and the minimum of water use efficiency were 8.11 and 6.15 kg m-3 related to the complete irrigation (I1) and severe drought stress (I3) respectively. In addition, a quadratic function was introduced as the optimum water-yield production function of cucumber crop (variety of super dominus hybrid) in the presence of superabsorbent, in sandy soil. Finally, the results showed that superabsorbent could prevent the significant reduction of cucumber crop yield in sandy soil and under drought stress conditions.

The flow fields over a trapezoidal labyrinth weir (two-cycle) and a piano key weir were simulated using Flow3D, studying the impact of each model on the flow field in the weirs and the coefficient of discharge in comparison with the available experimental data. Moreover, the models were investigated experimentally in a 12.5 m long, 0.3 m wide, and 0.4 m high rectangular flume under clear-water conditions. The results showed good agreement between the data from the numerical and experimental models. The piano key weirs had a higher coefficient of discharged compared with labyrinth weirs. The coefficient of discharge was observed to increase by 26 percent as the height of the PKW was increased by 50 percent (from 5 to 7.5 cm). This increase was 24 percent for labyrinth weirs.

In this study, the effect of water stress and different levels of superabsorbent on cucumber yield (variety of super dominus hybrid) in a farm with sandy soil was evaluated in Seimare region, Elam province, Iran. Experimental design was performed according to split plot method in a randomized complete block design. Three different levels of irrigation were considered as the main treatment including 100 (I1), 80 (I2) and 60 (I3) percent of crop water requirement and four levels of superabsorbent were used as secondary treatment including zero (S0), 15 (S1), 30 (S2) and 45 gm-2 (S3). According to the results, the effect of irrigation and superabsorbent treatments was significant on cucumber yield at 1 percent level. The average maximum and minimum crop yield were 3.7 and 1.97 kgm-2 which were corresponded to the full irrigation (I1) and severe drought stress (I3) treatments. In addition, the effect of irrigation and superabsorbent treatments was significant on water productivity of cucumber crop at 1 percent level. The maximum and minimum water productivity were 8.11 and 6.15 kgm-3 which were corresponded to the full irrigation (I1) and severe drought stress (I3) treatments. Also, a quadratic function was introduced as the optimum water-yield production function for cucumber crop (variety of super dominus hybrid) in the sandy soil amended with superabsorbent. Finally, it was concluded that the superabsorbent could prevent from the significant reduction of cucumber yield in sandy soil and under drought stress conditions.

The vortex tube is a structure with a slot along its longitudinal axis on top, which is installed across the width of the channel bed. This tube functions based on the gravitational force of sediment particles and swirling rotational force in the tube. It can transfer particles falling from its top slot to a specific side of the tube (Moazen and Shafai, 2003). Studies have shown the mechanism of this structure in separating the bed load. The current study used barriers with different shapes (square, triangle, and arched), heights and angles at the vortex tube upstream to increase the sediment trapping efficiency. These tests were conducted by changing the Froude number of the channel (flow hydraulic conditions). The results are provided below.

Saturated hydraulic conductivity is a vital soil propriety in controlling infiltration and runoff, drainage, extracting pesticides, and herbicides from soil profile and transfer them to ground water. The auger-hole method is the most famous and the most common method to measure the hydraulic conductivity (K) that have been used normally for years. Using this method is possible where the water table is high and in a one-meter range from the soil surface. In the measurement of saturated hydraulic conductivity some problems occur when the water table of the soil is very deep. In arid and semi-arid areas especially in summer, the water table is so low making it impossible to use ideal methods.To determine the hydraulic conductivity rates of soils above the water table, different methods are used. These methods have always been faced with weakness in theoretical bases or practical problems as well as being time consuming and costly. One of these methods is the shallow well pump-in test which is the most adaptable method used for this purpose. However, a new method has been developed to measure the hydraulic conductivity above water table which is called the Guelph Permeameter method. As the Guelph method was introduced by Reynolds and Elricks (1985), great changes have been made in this field, and due to the strong theoretical bases, being less time-consuming and cheaper to perform, Guelph method attracted lots of attention. The aim of this research was to calibrate the Guelph Permeameter for the measurement of saturated hydraulic conductivity using the Shallow Well Pump-in Test (SWPT) method at an experimental farm in Shahid Chamran University of Ahvaz. This research examines the calibration of Guelph Permeameter method by using shallow depth pumping test method for a loam soil in this region.

The purpose of this research was to evaluate the production quality of synthetic envelopes produced in Khuzestan factories and their performance in north and south Khuzestan soils, using laboratory methods. For quality control of the manufactured synthetic envelopes, first KOMO Standard tests were conducted followed by laboratory tests using upflow permeameter designed by Vlotman for these soils. Measured parameters in these tests were, discharge, Gradient Ratio and soil particle movement from the synthetic envelopes for soils of Dehkhoda and Ramshir projects. All Three types of pp450 synthetic envelopes A, B, and C manufactured in Khuzestan passed KOMO Standard test evaluations in this investigation. As to permeameter test results and Gradient Ratio tests (GR) envelope C for Ramshir soils and A for Dehkhoda soils were found suitable. It is therefore recommended to use these synthetic envelopes produced in Khuzestan soils with caution. These envelopes are more suitable where water table is to be lowered slowly to prevent rapid soil moisture depletion.

This investigation was performed to evaluate the suitability of threeSynthetic Envelopes PP450 manufactured by three local workshops in Khouzestan for drainage purposes in three projects, namely, Dehkhoda, Hendijan, and Ramshir projects (respectively, in the north, south, and in the middle of the Khouzestan province). Experiments were performed in the laboratory using an upward flow permeameter. Recommended criteria for the evaluation of the envelopes were steady discharge with time, gradient ratio (GR) for the determination of soil particle movement and envelope clogging potential, and hydraulic conductivity of soil envelope. According to the results for all the three criteria, type 1 envelope (with tiny pores) was considered suitable for Dehkhoda project soils while for Ramshir project soils, based on the same 3 criteria, envelope 3(with macro pores) was the most suitable followed by envelope 1, while envelope 2 (with medium-sized pores) had a lower technical performance for this soil. For Hendijan project soils, envelopes 3 and 2 were partially suitable because hydraulic conductivity of soil envelope was very low. Summing up, envelope 1 and 3 are recommended for Ramshir project and envelope 1 for Dehkhoda project soils .For Hendijan project soils, envelope 3 needs further testing before making recommendation .

Irrigated lands of Khuzestan are lands with shallow and saline groundwater, in which water losses of deep percolation during irrigation cause that irrigation water, because of the density difference, floats to the top of saline aquifer creating a fresh and saline water mixing zone. In new drainage issues such as reducing the depth of drain insertion aimed to an optimum use of water, dynamic studies on this region and evaluation of factors affecting its features are necessary. In the present study, two farms of sugarcane in south Khuzestan with two different drainage depths were selected. During the study, for each farm, installing pisometers at various depths and different distances from drain collector, the water level inside the pisometers and groundwater salinity were measured. Results indicated that by starting a heavy irrigation, hydraulic load is increased and hydraulic load variance between bottom layer (4 and 5 m) to the surface one ( 1 and 1.3 m) creates a vertical flow of saline water. As well, by reducing the drain insertion depth and increasing the distance from drain collector, in addition of the increase of hydraulic load to 10-15 cm, mixing zone`s thickness increases to 1 m and the mean salinity line in this region reduces to 5-10 percent. But, as well, this region`s features depend on the depth of impermeable layer and existence of sand lenses, as with low depth of impermeable layer and existence of sand lenses, because of the hydraulic load`s lack of increase, mixing zone`s thickness, is reduced and the salinity is highly increased.

An appropriate method to determine the hydraulic conductivity above water table is Guelph Permeameter. Using this method, experiments can be carried out by one person in a short period. Several investigators have commented on the systematic difference between the hydraulic conductivity obtained by Guelph Permeameter and Shallow Well Pumping Test (SWPT) methods. Therefore, the purpose of this research was to find a relationship between these two methods. In this study, to determine soil saturated hydraulic conductivity with Guelph Permeameter, Guelph Permeameter test was carried out in 5 agricultural regions of Khuzestan province and calibration of Guelph data was carried out with SWPT. In each region, Guelph Permeameter tests were conducted in 40 holes with 60 cm depth, under two (5 and 10 cm) constant heads in each hole. Five holes with 1m depth were dug to carry out the SWPT in all regions mentioned above. In each region, the number of holes with negative results and the ones with significant results for Kfs and in Guelph Permeameter were identified. Using Laplace single head analysis with zero capillary, single head analysis of Richards with α* = 12 and single head regression based on Richards analysis were used to remove non-logical results of Guelph Permeameter device. It was observed that the geometric mean of regression based on Richards and double head analysis were equal. Coefficients related to this analysis were determined using least squares, and mean of α* = 12 became equal to the primary hypothesis at a significance level of 95 %. In addition, because the standard deviation of α* in Guelph tests was high, it was better to consider it constant. It is concluded that in regions with average soil texture, hydraulic conductivity value obtained in shallow well pumping method was 4-5 times more than the hydraulic conductivity measured by Guelph method, while in regions with heavy soil texture, value of the hydraulic conductivity measured by shallow well pumping method was 2-3.5 times more than the hydraulic conductivity determined by Guelph method.

Determination of unsaturated soil hydraulic parameters are important for assessment and understanding of many processes. These processes include as: runoff and rainfall infiltration, salt, contaminations and nutrition elements transmission in soil and solution absorption by plant root. Recently, disc permeameter has been recognized as one of most current tool for measurement of unsaturated soil surface hydraulic parameters. In this research, for study of relation between unsaturated soil hydraulic conductivity and sorptivity curve,the field experiments were performed at six iterations to interval of 1 meter each other on three zons (first zone with silty loam texture, second and third zone with loam texture). At all iterations, steady infiltration rates were measuremented on soil surface in consective five suctions, 15, 10, 6, 3 and 0 cm recpectively. Then, sorptivity factors in each suction were estimated by methods of differentiation (unsteady analysis) and steady analysis. The results of this study indicated that, sorptivity curve (s(h)) similar as unsaturated hydraulic conductivity curve (k(h)) is followed an exponential function. Sorptivity factor had inverse relation with suction, so that sorptivity value increased with suction reduction. Also, the results of this study showed that unsteady analysis method estimate sorptivity value at all suctions more than steady analysis method and the differences are significant in suctions of 3 and 0 cm. The study results indicated soil sorptivity factor inverse relationship with α parameter and α parameter inverse relationship with soil structure resistance degree. Also, it is observed that sorptivity factor sensitivity to soil structure is more than hydraulic conductivity.

A new approach in drainage design call for the control of shallow water table at vicinity of the crop rootzone for the purpose of proper soil and water conservation. The objective of this study was to evaluate the effect of reducing drainage depth on salinity and water rate of drains. For this purpose، R 9-11 farm with average drainage depth of 2 and distance of 60 meters and a R 8-7 farm with depth of 1. 4 and distance of 40 meters of sugarcane in south Khuzestan were selected. During the study، constructing six pisometers groups in two farms with different distances from drain collector، the daily water table level and outlet drain flow rate and the salinity of groundwater، and outlet drain in each irrigation were measured respectively. Results indicated that by increasing the irrigation water، the difference of hydraulic load between the bottom layers to the top ones in both farms، leads the vertical flow upwards. In addition، by reducing the drain insertion depth، the groundwater rate of salinity reduces، but these changes of salinity depend on the impermeable layer depth. In addition، by reducing that drain salinity was affected by irrigation water and groundwater salinity and the difference of drain insertion depths، location of impermeable layer and sand lenses affect this salinity. In addition، by reducing the drain insertion depth، outlet drain flow rate was intensively reduced such that in R 9-11 and R 8-7 farms، outlet drain reached to 3. 86 and 0. 74 L/s، respectively.

The objectives of this research were to synthesize magnetite nanoparticles (Fe3O4) and determining its efficiency in Cadmium removal from aqueous solutions. Consequently, magnetite nanoparticles were synthesized and the effect of pH, contact time, Cadmium concentration and nanoparticles amount on cadmium removal efficiency were investigated in batch system. Scanning Electron Microscope (SEM), XRD and FTIR were used to characterization of the synthesized magnetite nanoparticles. SEM results showed that the diameter of the particles is 40-60 nm. Results also showed that the optimum pH value for adsorption was 6. The adsorption capacity increased and the adsorption efficiency decreased with increasing concentration of Cadmium ions and reducing the amount of adsorbent. The magnetite nanoparticles have advantages such as high removal efficiency and short reaction time and can be used as a method to remove Cadmium from aqueous solutions.

Among the heavy metals cadmium is of considerable environmental and health significance because of its increasing mobilization and human toxicity. The objectives of this research were to synthesize SDS modified magnetite nanoparticles (Fe3O4) and to determine its efficiency in cadmium removal from aqueous solutions. Modified magnetite nanoparticles were synthesized and the effects of pH and contact time on cadmium removal efficiency were investigated in batch system. Then kinetics and isotherm models coefficients were determined in the optimum pH and equilibrium time conditions. Scanning Electron Microscopy (SEM)، X-ray diffraction (XRD) and Fourier transform infra red (FTIR) were used to characterize the modified magnetite nanoparticles synthesized. The SEM results showed that the diameter of the particles is 40-60 nm. It was found that the optimum pH value for maximum adsorption of 10 mg/L cadmium by 0. 1 g adsorbent in 12 hr was 6. Kinetic study showed that the equilibrium time was 30 min. The adsorption kinetics fitted well using the Ho pseudo second-order kinetic model; however، the adsorption isotherm could be described by the Freundlich model. The maximum adsorption capacity of modified magnetite nanoparticles for Cd2+ was found to be 9. 604 mg/g. The results of this study indicated that the modified magnetite nanoparticles can be employed as an efficient adsorbent for the removal of cadmium from contaminated water sources

Two issues of the drainage systems which are less studied in the literature are drainage in layered soils and bi-level derange systems. Hence، it is necessary to do more research in these topics. Therefore the present study was carried out under above conditions in the Imam Khomeini Farming and Industrial Lands، located in the north of the Khuzestan province، Iran. In this area based on primary studies، lateral spacing was estimated about 70 m and they were installed at the depth of 2. 1m. But after two years of establish these drainage systems، it was observed that due to existence a soil layer with a very low infiltration rate (less than 10 time in compare with its above and below layers) at the depth of 110 to 160 cm، drainage systems in 500ha of these fields had low performance. Then، in order to overcome with this problem، the implementation of bi-level drainage system was proposed. Hence، a new drain line was installed at the depth of 1. 2m between the old drain lines. After establishment of these new drains one field was selected to evaluation the performance of this new system. In the selected field three rows of observation wells were installed (in total 20 observation wells). After equipment of these observation wells، water table fluctuation، inflow and outflow water values from the field were measured in 3 irrigation periods. Then the results of field observations were compared with the obtained results from analytical solution in the literature. Results show with establish new drain lines the problem of these fields are solved and the water table profile will drop-off to the below of root zone in less than 36hr. Also it was concluded that the rate of water table decline by moving from the end of field to the open collector of field will be increased and the discharge of deep drains are more than low-deep rains. Results show that analytical solution is not able to predict the water table profile with well accuracy and predicted values by this equation only in a small area of water table profile were consistent with the observed values in the field. The main reason of this difference was the specific situation of layers of the soil.

Sugarcane is cultivated in extensive area in Khuzestan and is irrigated by hydro-flume or syphon. In a field experiment during 2005-6 at Amir Kabire Agro-Industry, of every other furrow irrigation methods was used on sugarcane to study water Volume, application efficiency and water use efficiency of sugarcane. The experiment was conducted in a Completely Randomized Design with three irrigation level treatments, conventional method (conventional, variable every other furrow (alternative-furrow) and invariable every other (fixed furrow)). This experiment was carried out on. Cp69-1062 sugarcane Varity. The results showed that total consumed water was 29848, 21281 and 20657 m3/ha for conventional, fixed-furrow and alternate-furrow irrigation for conventional, fixed-furrow and alternate-furrow methods, respectively. The total amount of water used was reduced by 30.8% and 28.7%, respectively, in the alternate and fixed-furrow irrigation treatments compared to the conventional irrigation method. The results showed that Water application efficiency in were different levels. The water application efficiency were 41-50 percent (average %45) for conventional method and by irrigation fixed furrow were 74-83 percent (average %78) and by irrigation alternative-furrow were 77-87 percent (average %81) for 1-4 irrigations. water-use efficiency was 0.41, 0.58 and 0.7 kg/m3 (kg sugar production per m3 water used) for conventional, fixed-furrow and alternate-furrow methods, respectively.

This research was carried out to study the effect of water and salinity stresses on yield and yield components of maize (KSC-260) during different growth stages in farming years 2009-2010. The research consists of three levels of irrigation water (100, 75 and 50 % treatments I1 to I3) and three levels of salinity irrigation water (salinity of water river (S1), S1+ 1.5 and S1+3 dS/m treatments S1 to S3) during three growth stages as vegetative (Experiment 1), flowering (Experiment 2) and after flowering (Experiment 3). The experiments were arranged according to a randomized complete block design with split plot layout. The results of this study showed that the interaction of water and salinity stresses had not any significant effect on factors (number of seeds per ear, 100-grains weight, grain yield, biological yield and harvest index) during all experiments. I3 and S3 treatments showed respectively 20, 23, 27.5 and 20.5, 26.4, 13.2 % reduction with respect to I1 and S1 treatments in experiment 1, experiment 2 and experiment 3, respectively. Flowering stage was the most sensitive growth stage to water and salinity stresses.

In this investigation groundwater modeling is attempted monitoring water table fluctuations of Jiroft basin using PMWIN computer model. Parameters like hydraulic conductivity, specific yield and groundwater abstraction and recharge were estimated by matching of the data from 41 observation wells for the period 1381-1386 to those predicted by the model using automatic calibration procedure with PEST. Verification of the model for a 6 month period in 1387 showed that the predicted water levels had a good match with the observed water levels with a root mean square error of 0.865. The verified model was used for the prediction of groundwater table behavior for the next 4 years.

Sugarcane has been cultivated in an extensive area in Khuzestan and irrigated by hydro-flume or siphon and furrow. In a field experiment during 2005-6 at Amir Kabir Agro-Industry, Khuzestan, the effect of every other-furrow irrigation method was studied on sugarcane in regard to irrigation water volume, water use efficiency and quality and quantity of sugarcane. The experiment was conducted in a completely randomized design with three irrigation treatments, including conventional method (blank), variable every other furrow(alternative furrow) and fixed every other furrow. This experiment was conducted by cv. Cp69-1062 sugarcane. The results showed that water use efficiency rates were 0.41, 0.58 and 0.7 kg/m3 for conventional, fixing furrow and alternative, respectively. However, water use efficiency rates were not significantly different in treatments. It had minimum amount of water use efficiency in every other furrow treatments. Maximum water use efficiency, quality and quantity of sugarcane were obtained every other irrigation. Maximum irrigation water was used in conventional treatment and resulted in minimum irrigation, quality sugarcane and water use efficiency. It produced 14.5 ton/ha sugar for 20604 m3/ha application of irrigation. Sugarcane quality and quantity characteristics in variable treatments, except for length number per hectare, were not significant.