Showing 26 results for Abedi koupai
J. Abedi Koupai, S. S. Eslamian, M. Khaleghi,
Volume 16, Issue 62 (Winte - 2013 2013)
Abstract
Crisis of quality and quantity of water resources is one of the most important problems in arid and semi-arid areas such as Iran. Wastewater treatment and reuse as a potential source of water can not only compensate for the water scarcity but also can prevent the hazardous pollutants from entering the groundwater and surface water resources. There are various methods to improve water quality, among which method of filtration is an effective and efficient method to remove elements. The most important issue for filter system is the selection of adsorbent materials. In this work, the tire chips were used as adsorbent. Column adsorption tests in a pilot system were conducted in two distinct steps using two types of water, including salt water and industrial effluents. Each test was conducted as a factorial experiment with three factors based on a completely randomized design with three replications. Three factors were studied including particle size (2-5 mm and 3-5 cm), filter thickness (10, 30 and 50 cm) and sorbent contact time with solution. The results showed that adsorption rate increased by increasing the thickness of the filter and sorbent contact time with solution. The best performance of reducing the salinity was observed in the treatment with 50 centimeter thickness and 24 contact hours. The salinity of this treatment was reduced by 20.3 percent (in the test with salt water) and 11.2 percent (in the test with industrial effluents). This filter reduced the heavy metals of lead, zinc and manganese up to 99, 72.1 and 41.4 percent, respectively. Also, the performance of millimeter and centimeter particles did not show a significant difference. Generally, the tire chips showed a proper performance to improve the water quality especially for industrial wastewater.
L. Divband, S. Boroomand Nasab, M. Behzad, J. Abedi Koupai,
Volume 17, Issue 65 (fall 2013)
Abstract
Heavy metals in water resources are one of the most important environmental problems in most of countries. Up to now, various methods for removing these metals including using low price materials have been used. In this study, two new absorbents (zizyphus spinachristi leaf and its fly ash) were studied for adsorption of cadmium from aqueous solutions using batch experiments. The effect of contact time, pH, and amount of adsorbent on adsorption efficiency was evaluated and the best kinetic and isotherm model was determined. Results showed that optimal absorption of pH was 5 and 6 for zizyphus spinachristi leaf and its fly ash, respectively. The equilibrium time was 45 min for zizyphus spinachristi leaf and 30 min for ash. Adsorption efficiency was increased by increasing the adsorbent dose. By comparing the parameters of isotherm models, it was observed that the cadmium adsorption capacity of fly ash (4.27 mg/gr) was higher than that of zizyphus spinachristi (3.91 mg/gr).
A. Ahmadnejad, J. Abedi Koupai, F. Mousavi,
Volume 17, Issue 66 (winter 2014)
Abstract
Sesame (Sesamum indicum L.) is one of the most important oilseed crops in the world. Drought stress is one of the environmental factors limiting sesame production. The effects of water deficiency can be reduced by inoculation of plant roots with mycorrhiza fungi. In this experiment, the objective was to determine the effects of different levels of water application (60, 80 and 100% of soil moisture depletion) using surface drip irrigation method and inoculation of plants with mycorrhiza on WUEag of sesame. The experiment was arranged using a factorial design based on randomized complete block design with three replications. The field experiment was conducted at the Agricultural Research Farm of Isfahan University of Technology in 2011. Results showed that the effect of irrigation regime on WUEag of seed yield was not significant. However, the effect of mycorrhiza on WUEag of seed yield was significant. The highest WUEag (0.74 kg/m3) was related to irrigation regime of 80% and mycorrhiza. The effect of irrigation regime and mycorrhiza on WUEag of oil yield were significant. The highest WUEag (0.43 kg/m3) was related to irrigation regime of 100% and mycorrhiza inoculation.
J. Abedi Koupai, J. Khajeali, R. Soleimani, R. Mollaei,
Volume 18, Issue 67 (Spring 2014)
Abstract
As increasing of disaster such as drought and pest invasion in recent decades, it is essential to find out practical
approaches in optimizing water use and water management for reduce the adverse effects of this disaster in agriculture.
In order to study the effects of water stress and pest stress on corn yield, an experiment was conducted in the research
farm of Isfahan University of Technology. In sprayed and non sprayed of the field, a factorial design, based on the
completely randomized block, was carried out with three treatments of irrigation regimes including intensive stress
(50% water requirement), moderate stress (75% water requirement) and no water stress in four stages of corn growth
from seed germination until tasseling, from tasseling until milky, from milky until harvest and the whole period of corn
growth, in four replications for one year (2005). The results showed that applying water stress on corn reduced seed
yield between 6-62% and also decreased other agronomic characters except protein percentage. Water stress in non
sprayed condition, reduced significantly more physiological characteristics of corn compared to the sprayed condition.
Intensive water stress and pests stresses increasd 3 and 13% of percentage protein, respectively. In sprayed condition
applying moderate stress in first stages of corn until the first of third stage is suggested in drought condition.
J. Abedi Koupai, M. Salehi-Sirzar, S. S. Eslamian, J. Khajeali, Y. Hosseini,
Volume 18, Issue 68 (summer 2014)
Abstract
In order to investigate the effect of pest and water stresses on different growing stages of cowpea (Vigna sinensis) and pest occurrence, an experiment was conducted in Khazaneh Research station of Isfahan University of Technology. The experiment was carried out in a factorial complete randomized block design, in two different farms, with and without insecticide application. The treatments included severe water stress (50% water requirement), moderate water stress (75% water requirement) in four stages of cowpea growth, the first stage (from seed germination until flower in, second stage (from flowering until pod-filling), third stage (from pod-filling until harvesting) and the whole period of cowpea growth, in three replications. There was a control treatment in each farm with no stress in the whole period of cowpea growth, in three replications. The results showed that water stress had no significant effect on percentage of protein and mineral material. Result also showed that water stress had a significant effect (P≤ 0.01) on population of insects. Water stress significantly (P≤ 0.01) reduced the population of nymphs and adults of Empoasca decipiens Paoli and leaf minor damages, but water stress increased population of Thrips tabaci Lind. Considering the duration of first stage of growth (63 days), it is concluded that this stage had less sensitivity to water stress than the other stages. In regions, where farmers encounter water shortage for cowpea planting, the best performance can be obtained when moderate water stress (75% water requirement) is applied at the first stage of growth.
J. Abedi Koupai, S. S. Eslamian, S. Y. Hasheminejad, R. Mirmohammad-Sadeghi,
Volume 18, Issue 69 (fall 2014)
Abstract
Phytoremediation models are important to understand the processes governing phytoremediation and the management of contaminated soils. Little effort has been made for evaluating the potential of the phytoremediation of metals based on the mathematical models. Therefore, the purpose of this study was modeling the phytoremediation of the nickel-contaminated soils. For this purpose, a model was recommended for estimating the rate of the phytoremediation of nickel from the soil by means of relative transpiration reduction and concentration of nickel in the plant functions. To evaluate the model, soil was contaminated with different levels of nickel by nickel nitrate. Then, the pots were filled with contaminated soil and Basil (ocimum tenuiflirum L.) seeds were planted. To avoid the dry tension, the pots were weighed and irrigated to the point of field capacity (FC) at short time intervals (48 hours). The plants were harvested in four times. At each harvesting stage, the relative transpiration values and nickel concentration in the soil and plant samples were measured. The performance of the model was evaluated by statistical methods such as Maximum Error, Root Mean Square Error, Coefficient of Determination, Efficiency of Model and Coefficient of Residual Mass. Results demonstrated that in the case of nickel contamination in soil, changes in the relative transpiration of Basil can be measured by the two proposed models and the linear model (R2=0.94) has a better performance compared to the nonlinear one (R2=0.84). Also the model obtained from the combination of linear function and nickel's concentration in soil has a relatively good (R=0.7) fit with the measured values of the remediation rate of nickel in soil.
J. Abedi Koupai, M. Golabchian,
Volume 19, Issue 72 (summer 2015)
Abstract
Nowadays, due to the high potential of advanced simulation models for groundwater, these models are comprehensively applied in the management and exploitation of groundwater resources. The aim of this study was to investigate and simulate the groundwater resources in Kouhpayeh-Segzi watershed and in particular estimate the hydrodynamic coefficients of unconfined aquifer. After preparation of input layers, efficient parameters in modeling, boundary conditions and aquifer gridding were determined. Then, based on the available data, the model was run and calibrated in a steady state for the water year 2002 and in a transient state for water years between 2002 and 2004. The simulation outputs were confidently verified for the water year 2005. The results indicated that the hydraulic conductivities and storage coefficients were ranged on sub-basin from 15.26 to 19.87 m/day and 0.0107 to 0.0186, respectively. From aquifer's hydrograph for a period from 1995 to 2012, water level dropped about 25 cm. This may be due to two irrigation networks (green area). This leads to rising water level. By ignoring these recharge areas, water level declined up to 80 cm per year. With sensitivity analysis in transient state to evaluate the efficacy of each parameter, the accuracy of the results of calibration model was confirmed. In addition, the hydraulic head values computed by MODFLOW were in good agreement with those that were collected from all piezometers.
J. Abedi Koupai, S. Soltanian, M. Gheysari,
Volume 19, Issue 72 (summer 2015)
Abstract
Lack of knowledge on soil geotechnical properties can cause many problems in the construction and maintenance of irrigation and drainage networks. In general, all of unconventional soils such as gypsiferous soils can cause some problems to irrigation canals. Some studies have been conducted on a variety of problematic soils, but still there is a need for more research activities and field studies. This research was conducted to study the impact of adding perlite and pumice (5%, 10% and 15%) and micro silica (1%, 5% and 10%) on some mechanical properties of soil including shear stress, bearing capacity and Atterberg limits. Statistical analysis was done to compare their averages (P<0.01). Results showed that micro silica had the most effect on shear, bearing and condensation parameters and Atterberg limits of gypsiferous soil, and it improved these parameters of soil. Pumice improved shear, bearing and condensation properties of gypsiferous soil. Perlite reduced the shear, bearing and condensation properties of gypsiferous soil.
J. Abedi Koupai, K. Norouzian, N. Abbasi,
Volume 19, Issue 73 (fall 2015)
Abstract
To improve the engineering properties of fine-grained soils, the use of various additives has always been considered important. In this study, the effect of hydrated lime on compressive strength of clay soils was studied in both optimum moisture and saturated modes. For this purpose, by adding varying amounts of hydrated lime (0, 1, 3and 5%) to the clay, several samples were prepared and tested by the standard proctor and Harvard miniature compaction apparatus. Then the samples were tested for unconfined compressive strength in optimum moisture and saturated modes after different curing days (7, 14, 28 and 90 days). The results showed that by increasing the amount of hydrated lime, the maximum dry unit weight was reduced and the optimum moisture was increased. Increasing the hydrated lime also increased the compressive strength of the soil in both dry and saturated modes and this resistance increase was significantly influenced by cured days and the amounts of hydrated lime. The results showed that the rate of 5% hydrated lime was the maximum compressive strength, but with regard to softening factor, the amount of 3% hydrated lime was determined as the optimum value.
M. Goodarzi, J. Abedi Koupai, M. Heidarpour, H. R. Safavi,
Volume 19, Issue 73 (fall 2015)
Abstract
Due to the time and space changes of hydrological events in the arid and semi-arid regions, recharge measurement in these areas is very difficult. Hence, groundwater recharge is a complicated phenomenon for which there is not a fixed method to determine. The aim of this research was to develop a method for estimation of groundwater recharge based on a hybrid method. In this study, a hybrid method for calculating recharge was presented by combining empirical methods with a mathematical model, MODFLOW, and AHP analysis. The results showed that the most important parameters affecting groundwater recharge are soil properties, unsaturated thickness, land cover, land slope, irrigation and precipitation, from which the soil properties and precipitation are most important. The results showed that the overall impact of small changes in precipitation and temperature significantly affect the groundwater recharge, and heavy soils are much more sensitive to these changes than light soils. By changing 10% precipitation, the recharge rate is changed between 16% and 77% and by changing 1ºC temperature, the recharge rate is changed between 6% and 42%. Also, results showed that precipitation and evapotranspiration changes in four months including December, January, February and March had significant effects on annual recharge rate. Using the results of this research, the vulnerable areas of the plain, appropriate places and time for artificial recharge could be identified. Overall, the results of this study can be useful in various aspects of groundwater management.
R. Mollaei, J. Abedi Koupai, S. S. Eslamian,
Volume 20, Issue 75 (Spring 2016)
Abstract
Water scarcity forced farmers to use wastewater as water source, without considering its effects on environment and resultant contamination of soils and plants especially with heavy metals. The objectives of this study are to evaluate the application effects of zeolite as soil amendments on the uptake of Cd by spinach (Spinach Oleares L.) irrigated with wastewater (containing 10 ppm Cd). Different levels amounts of zeoilte (0, 1% and 5% w/w) were added to the soil and the experiment was conducted as a completely randomized design in a green house with 3 replications. The results indicated that, the addition of zeolite 1% (w/w) in soil treated with wastewater reduced cadmium concentration in plant, and consequently the percentage of extractable Cd using DTPA was decreased. However, application of zeolite 5% (w/w) increased the soil salinity, and as a result increased Cd concentration in the plant but this increase was not statistically significant, comparing with control. Spinach biomass did not differ significantly under irrigation with wastewater, but the Cd available in wastewater caused a decrease in Spinach biomass yield.
M. M. Matinzadeh, J. Abedi Koupai, H. Nozari, A. Sadeghi Lari, M. Shayannejad,
Volume 20, Issue 76 (Summer 2016)
Abstract
In this research, a comprehensive simulation model for water cycle and the nitrogen dynamics modeling including all the important processes involved in nitrogen transformations such as fertilizer dissolution, nitrification, denitrification, ammonium volatilization, mineralization, immobilization as well as all the important nitrogen transportation processes including nitrogen uptake by the plant, soil particles adsorption, upward flux, surface runoff losses and drain losses, was used for fertilizer management modeling in a sugarcane farmland in Imam Khomeini Agro-Industrial Company using a system dynamics approach. For evaluating the model the data collected from Imam Agro-Industrial Company equipped with a tile drainage system with shallow ground water and located in Khuzestan province, Iran, were used. The statistical analysis of the observed and simulated data showed that the RMSE for determining the accuracy of simulation of the nitrate and ammonium concentration in drainage water is 1.73 mg/L and 0.48 mg/L, respectively. The results indicated that there is good agreement between the observed and the simulated data. Nine scenarios of fertilization at different levels of urea fertilizer were modeled including one scenario of 400 kg/ha, two spilit scenarios of 350 kg/ha, two spilit scenarios of 325 kg/ha, two spilit scenarios of 300 kg/ha, one scenario of 280 kg/ha and one scenario of 210 kg/ha. Results of the modeling showed that the scenario of 210 kg/ha has the highest nitrogen use efficiency (52.3%) and the lowest nitrogen losses consisted of denitrification, ammonium volatilization and drainage losses (17.82, 7.16 and 92.59 kg/ha, respectively). The results revealed that increasing the consumption of urea fertilizer greater than 210 kg/ha increased the overall nitrogen losses and reduced the nitrogen use efficiency. Meanwhile, this model can be used for managing the fertilizer and controlling the nitrate and ammonium concentrations in the drainage water to prevent the environmental pollution. Also, the system dynamics approach was found as an effective technique for simulating the complex water-soil-plant-drainage system.
M. M. Matinzadeh, J. Abedi Koupai, A. Sadeghi-Lari, H. Nozari, M. Shayannejad,
Volume 23, Issue 3 (Fall 2019)
Abstract
Selection of drainage equation with acceptable accuracy has always been a challenge for designers to design subsurface drainage systems. In this research, seven steady state drainage equations were used for predicting daily and cumulative drainage rate on a farmland of sugarcane in Imam agro-industrial Company. These drainage equation included Hooghoudt, Ernst, Kirkham and Dagan that have been developed in the past and Mishra and Singh, Henine and Yousfi et al that recently developed. The statistical indices consist of P-value, RMSE, R2 and Percentage Error of estimating cumulative drainage rate were calculated for Hooghoudt equation 0.9501, 1.49 (mm/day), 0.80 and -0.19%, respectively. For Ernst equation 0.0001, 2.46 (mm/day), 0.34 and 16.98%, respectively. The result of performance of drainage equations revealed that Hooghoudt and Ernst equation were as the equations with the highest and lowest accuracy in predicting drainage rate, respectively. Also from the newly developed equations, the Yousfi et al equation was found with relatively well accuracy to predict the drainage rate. This equation was placed in second rank after Hooghoudt equation and other equations showed poor performance. Thus, with selection of the appropriate drainage rate, the Hooghoudt equation is suggested for designing of drain spacing in medium to heavy textured soils such as sugarcane agro-industrial.
J. Abedi Koupai, B. Babaiee,
Volume 23, Issue 4 (Special Issue of Flood and Soil Erosion, Winter 2019)
Abstract
Simulation of the hydraulic behaviour of the river basin boundaries is important for river engineering projects, prediction of flood damages in different conditions and economic feasibility studies, flood control, and other social programs related to the system of the river. In this study, river bed and flood zoning map in the range of over 155 km from the Zayandehrud dam to Nekouabad Diversion Dam were addressed by using the software's ArcGIS, HEC-RAS and HEC-GeoRAS extension. For this purpose, a digital elevation map in 1: 250,000 scale was provided and cross-sectional area was divided in 1085. Manning roughness coefficient was determined by Cowan. Finally, data entered into the software HEC-RAS and was analysed. After determining the area of flood in the return periods of 2, 5, 10, 25, 50, 100 and 200 years in all cross sections, the results were entered into the ArcGIS environment and flood zoning maps were obtained. The results showed that of the 200-year flood lands, 96% of the land flood was related to the return period of 25 years.
M. Javaheri Tehrani, S. F. Mousavi, J. Abedi Koupai, H. Karami,
Volume 24, Issue 2 (Summer 2020)
Abstract
In the last few decades, the use of porous concrete to cover the sidewalks and pavements as an interface to collect the urban runoff has been increased. This system is economically more efficient than other runoff-pollution reduction methods. To design a runoff control system and reduce its pollution, it is necessary to determine the hydraulic and dynamic properties of the porous concrete (with and without additives). In this research, the effects of cement type (2 and 5), water to cement ratio (0.35, 0.45 and 0.55), fine grains percent (0, 10 and 20%), the type of additive (pumice, industrial pumice, perlite and zeolite), and the added additive percent (5, 10, 15 and 20%) on the physical properties of the porous concrete (porosity, hydraulic conductivity and compressive strength), each with three replications, were investigated using robust design. Qualitek-4 software was also used to discuss the results. The results showed that to obtain the highest porosity in the mixing scheme of the porous concrete, no fine grains, cement type 2 and 15% industrial pumice should be used, and water to cement ratio should be 0.35. Also, the water to cement ratio of 0.55, 0% fine grains, type 2 cement and 15% industrial pumice resulted in the highest value of hydraulic conductivity in the porous concrete. Finally, the water to cement ratio of 0.55, 20% fine grains, type 2 cement and 5% zeolite led to the maximum compressive strength. In general, it was not possible to reach a logical conclusion in this research with the least costs without employing the robust design.
M.m. Matinzadeh, J. Abedi Koupai, M. Shayannejad, A. Sadeghi-Lari , H. Nozari,
Volume 25, Issue 4 (Winiter 2022)
Abstract
Using water and fertilizer management at the farm level can be increased water use efficiency and reduce the volume of drainage water, fertilizer losses, and other pollutants in farmland with deep underground drains such as Khuzestan agro-industrial Companies. In the present study, a comprehensive simulation model for the water cycle and the nitrogen dynamics modeling was used for water and fertilizer management modeling on farmland of sugarcane in Imam Agro-Industrial Company using a system dynamics approach. To reduce irrigation water consumption and nitrogen fertilizer losses, five different scenarios were considered including four scenarios of water management consist of 5, 10, 15, and 20 percent reduction in the amount of irrigation water (I1, I2, I3, and I4) compared to the current situation of irrigation in Imam agro-industrial Company (I0), and one scenario of integrated water and fertilizer management (20% reduction in the amount of irrigation water and urea fertilizer 210 Kg/ha, I4F). The results of modeling showed that the scenario of I4F caused to reduce 31, 70, 71, 70, and 85 percent of the cumulative volume of drainage water, cumulative nitrate and ammonium losses, total losses of cumulative nitrate, and ammonium by tile-drain and cumulative losses of denitrification process, respectively. Thus, the implementation of this scenario, not only saves water and fertilizer consumption but also reduces environmental pollution effectively. So the scenario of I4F (amount of irrigation water for six months 2656 mm and urea fertilizer 210 Kg/ha) is recommended for sugarcane in the Imam agro-industrial Company.
N. Pourabdollah, J. Abedi Koupai, M. Heidarpour, M. Akbari,
Volume 25, Issue 4 (Winiter 2022)
Abstract
In this study accuracy of the ANFIS and ANFIS-PSO models to estimate hydraulic jump characteristics including sequence depth ratio, the jump length, the roller length ratio, and relative energy loss was evaluated in stilling basin versus laboratory results. The mentioned characteristics were measured in the stilling basin with a rectangular cross-section with four different adverse slopes, four diameters of bed roughness, four heights of positive step, three Froude numbers, and four discharges. The average statistical parameters of NRMSE, CRM, and R2 for estimating hydraulic jump characteristics with the ANFIS model were 0.059, -0.001, and 0.989, respectively. While, the mean values of these parameters for the ANFIS-PSO model were 0.185, 0.002, and 0.957, respectively. The results indicated that these models were capable of estimating hydraulic jump parameters with high accuracy. However, the ANFIS model was moderately more accurate than the ANFIS-PSO model to estimate the sequence depth ratio, the jump length, the roller length ratio, and relative energy loss.
J. Abedi Koupai, A.r. Vahabi,
Volume 27, Issue 2 (Summer 2023)
Abstract
Awareness of water resources status is essential for the proper management of resources and planning for the future due to the occurrence of climate change in most parts of the world and its impact on different parts of the water cycle. Hence, many studies have been carried out in different regions to analyze the effects of climate change on the hydrological process in the coming periods. The present study examined the effects of climate change on surface runoff using the Atmosphere-Ocean General Circulation Model (AOGCM) in Khomeini Shahr City. The maximum and minimum temperatures and precipitation of the upcoming period (2020-2049) were simulated using a weighted average of three models for each of the minimum and maximum temperatures and precipitation parameters based on the scenario A2 and B1 (pessimistic and optimistic states, respectively) of the AOGCM-AR4 models. The LARS-WG model was also used to measure the downscaling. The HEC-HMS was used to predict runoff. The effects of climate change in the coming period (2020-2049) compared with the observation period (1971-2000), in the A2 scenario, the minimum and maximum temperatures would increase by 1.1 and 1.6 Degrees Celsius, respectively, and the precipitation would decrease 17.8 percent. In the B1 scenario, the minimum and maximum temperatures would increase by 1.1 and 1.4 degrees Celsius, respectively, and the precipitation would decrease by 13 percent. The results of runoff were different in the six scenarios in the way the most runoff reduction is related to the scenario of fixed land use and scenario A2 (22.2% reduction), and the most increase is related to the scenario of 45% urban growth and scenario B1 (5.8% increase). So, according to increase urban texture in the future and consequently enhance the volume of runoff, this volume of runoff can be used to feed groundwater, irrigate gardens, and green space in the city.
J. Abedi Koupai, A. Chehreraz, F. Dadvand,
Volume 27, Issue 4 (Winter 2023)
Abstract
The scarcity of freshwater resources increases the importance of seawater and brackish water desalination processes. However, a large amount of specific energy requirements, and high operational costs, present a big challenge in adopting desalination technologies. Due to high expenses of energy, desalination of saline waters by low-cost methods is important. The objective of this research was to investigate the ability of two adsorbents (zeolite and graphene oxide) to remove salinity ions from aqueous solutions in Caspian Sea water and water of the well of the Dark zone in Isfahan. At first, some graphene oxide was made according to Homer's method. Then, the characteristics of graphene oxide were known by Fourier transform infrared spectroscopy and using an electron microscope. After that, the ability of adsorbents to remove salinity agent cations and anions was evaluated. To investigate a fixed-bed zeolite column with graphene oxide (GO) layer was used to remove Na+, K+, Ca2+, Mg2+, and Cl– from 50 cc of saline water. Also, Hexadecyl trimethylamine (HDTMA) was used to modify natural zeolites. The results showed that among the adsorbents for the water of the well in the Dark zone, 30 mg graphene oxide with 13 gr zeolite had the highest adsorption rate (23.84 percent of salinity reduction), and for Caspian Sea water, 13 gr zeolite modified by surfactants had the highest adsorption rate (23.43 percent of salinity reduction). Also, the removal of cations and anion followed the sequence: K+ >Ca2+ >Mg2+ >Cl– >Na+.
M. Baki, J. Abedi Koupai,
Volume 28, Issue 1 (Spring 2024)
Abstract
The improvement of water consumption efficiency is very significant, especially in arid and semi-arid regions. In this research, the effects of three hydrogel rates (0, 10, and 50 Mg ha-1) and three irrigation regimes (50%, 70%, and 100% of water requirement) on growth, yield, and oil production of Thymus daenensis were studied in a lysimetric experiment. The process of hydrogel synthesis was performed with sodium alginate as the main bone of the polymer and acrylic acid and acrylamide as monomers with the rapeseed meal biochar was made at 300 ºC. The results showed that the essential oil content produced by the plant was impressed by the hydrogel application. The essential oil content increased with an increase in water deficit, but the essential oil yield decreased in the lysimeters with water deficit compared to the ones without water stress. Besides, the application of 50 Mg ha-1 hydrogel caused a 17% increase in the dry matter and a 12% increase in the plant's height. According to the results of this experiment, the application of hydrogel caused the improvement in most characteristics of the Thymus daenensis in water stress conditions.
