Research Paper
Mohsen Dehghani; Masoud Tadayonnejad; Mohammad Feizy
Abstract
In order to study the effect of irrigation frequency and water quality on yield and yield components of wheat, a study was conducted in Rodasht Agricultural Research Station, for 3 years. The experiment was laid in a randomized complete block design with three replications. Irrigation water quality ...
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In order to study the effect of irrigation frequency and water quality on yield and yield components of wheat, a study was conducted in Rodasht Agricultural Research Station, for 3 years. The experiment was laid in a randomized complete block design with three replications. Irrigation water quality treatments had electrical conductivities (EC) of 4, 8, and12 dSm-1 and were assigned to the main plot. Treatments of irrigation frequency were based on the percentage of management allowable depletion (30%, 50%, and 70%) and were allocated to the sub-plots. Statistical analysis results showed that the effect of irrigation water quality and irrigation frequency on the yield, water use, water use efficiency, weight of 1000 grains, and protein content was significant at the one percent level. The highest yield was produced by 30% management allowable depletion and 4 dSm-1irrigation water EC and reached 14593 kg.ha-1, while the lowest yield belonged to 70% management allowable depletion and 12 dSm-1 irrigation water EC yielding only 7347 kg.ha-1. The highest percentage of protein was related to the same treatment. The highest water use efficiency of 0.99 kg.m-3 belonged to 70% management allowable depletion and 4 dSm-1 irrigation water EC.
Research Paper
Hamed Hasanzadeh; Abdolhossin Mohammadi; Ebrahim Zakerifard; Maryam Mohammadi
Abstract
In order to evaluate the effect of different irrigation regimes on yield and yield components of 4 onion cultivars in a warm and humid climate, an experiment was performed as split plot design in RCBD with 4 replications. Main plots consisted of 4 irrigation regimes (irrigation after I1=35±3, ...
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In order to evaluate the effect of different irrigation regimes on yield and yield components of 4 onion cultivars in a warm and humid climate, an experiment was performed as split plot design in RCBD with 4 replications. Main plots consisted of 4 irrigation regimes (irrigation after I1=35±3, I2=50±3, I3=65±3 and I4=80±3, mm evaporation from class A pan) and sub-plots consisted of 4 onion cultivars (‘White Grano’, ‘Admiral’, ‘Primavera’ and ‘Mineroa’). Seeds were sown in nursery and, after 2 months, transplants were planted in the field at 10×30 cm spacing. After bulb growth stopped and onion neck dried up, leaf number, plant height, bulb length, number of layers, dry matter, yield, and water use efficiency (WUE) were measured. Results showed that there was no significant difference between irrigation treatments in bulb length, layers number and dry mater. However, yield decreased by irrigation intervals up to 65 mm evaporation from class A pan, but it increased significantly in irrigation interval of 80 mm evaporation. Vegetative growth increased by reduction of irrigation interval. The highest WUE was observed in ‘Withe Grano’ and ‘Primavera’ cultivars in 80 mm evaporation treatment (5.528 and 5.381 kg/m3) and the least was in ‘Primavera’ cultivar in 35 mm evaporation treatment (1.858 kg/m3). WUE increased by reduction of irrigation in all cultivars. For ‘White Grano’, ‘Admiral’ and ‘Primavera’ cultivars recommended irrigation intervals is 19 days in January, 20 days in February , 15 days in March, and 12 days in April, based on 80 mm evaporation treatment. In the case of ‘Mineroa’ cultivar, considering no significant difference between the highest irrigation treatments with 65 mm evaporation treatment, it is recommended that irrigation intervals be 15 days in January, 17 days in February , 12 days in March, and 10 days in April. Under the condition of this study, White Grano cultivar, followed by Admiral, performed higher than the other cultivars, especially with respect to WUE and yield. Therefore, they are recommended for planting in the region.
Shahram Karimi; Rasoul Asadi; Mohammadeza Mohammadrezakhani
Abstract
In order to investigate the effect of deficit irrigation and position patterns tube to increase water use efficiency of cotton, a field experiment was carried out during 2009 and 2010 growing season at experimental farm of Orzoueyeh Agriculture and Natural Resources Research Center in Kerman province. ...
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In order to investigate the effect of deficit irrigation and position patterns tube to increase water use efficiency of cotton, a field experiment was carried out during 2009 and 2010 growing season at experimental farm of Orzoueyeh Agriculture and Natural Resources Research Center in Kerman province. The treatments were laid out in strip split plot a Randomized Complete Block Design with three replications. The treatments were comprised of three levels of irrigation including 100, 80, 60 percent of crop water requirement in main plot and sub plot consisted of two irrigation systems (surface drip irrigation system (S1), subsurface drip irrigation system (S2)) and two tape position patterns (conventional (L1) and alternative (L2)). The results showed that In comparison with 100 percent of crop water requirement, 80 percent of water requirement caused parsimony of water usage equal 1300 m3 ha-1, and yield, WUE, number of bolls per plant and bolls weight increased 8.5%, 4%, 10% and 2.5% respectively. Also I3 compared with I1 savin about 3400 m3 ha-1 of irrigation water, and increase WUE was 8% but yield loss, number of bolls per plant and bolls weight decreased 18%, 25% and 18% respectively. Considering the results obtained in this study in the light of water saving as the main object in deficit irrigation and water use efficiency (WUE) for cotton cultivation in Orzoueyeh, the 80% of crop water requirement on subsurface drip irrigation is preferred.
Research Paper
Hedyeh Pouryazdankhah; Mohammadreza Khaledian
Abstract
In most cases, to predict soil moisture status before installing irrigation system, some simulations are performed by mathematical models to achieve a correct design and supply plant water requirement. Furthermore, nowadays, to increase water use efficiency, no-tillage system is being considered by many ...
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In most cases, to predict soil moisture status before installing irrigation system, some simulations are performed by mathematical models to achieve a correct design and supply plant water requirement. Furthermore, nowadays, to increase water use efficiency, no-tillage system is being considered by many experts, because of its high water saving potential. In this study, the performance of HYDRUS-2D has been assessed for both systems i.e. conventional and no-tillage systems. Hence, a field under corn crop and irrigated with tape drip irrigation was considered for each system, in south of France in a Mediterranean climate. Soil moisture at different depths was measured by a neutron probe before and after irrigation in the experimental fields and was compared with simulated moisture according to two statistical indices, i.e. RMSE and EF. In the conventional tillage system, considering the temporal variability of soil hydraulic properties before irrigations, the model could not satisfactorily simulate the whole 29-day study period; because ploughing caused increase in pores of the soil and, consequently, increased soil hydraulic conductivity (Ks). After the first irrigation, Ks was reduced because of the compaction of the first layer, which resulted in some discrepancies in model simulations, where accounting temporal variability of soil hydraulic properties improved the simulations of model. But, in no-tillage system, by accounting soil hydraulic properties before irrigations as input, the model could simulate the whole study period, because in this system, structure of the soil and, consequently, soil Ks changed negligibly and, therefore, the model could simulate more realistic results.
Research Paper
Mohammadreza Mahboobi; Hossinali Nkhaey; Ahmad Rezvanfar; Hamid Movahed Mohammadi
Abstract
Optimizing the management of water resources and improving irrigation efficiency is not possible without the beneficiaries' education. Also, identifying the educational needs of the beneficiaries is the first step in designing the educational programs that are to be executed for optimizing management ...
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Optimizing the management of water resources and improving irrigation efficiency is not possible without the beneficiaries' education. Also, identifying the educational needs of the beneficiaries is the first step in designing the educational programs that are to be executed for optimizing management of water resources and improving irrigation efficiency. This study investigated the educational needs of beneficiaries of classical pressurized irrigation systems (CPIS) in Golestan province. The geographical region of study covered Gorgan, Gonbad, Kalaleh, Minoodasht, Ali Abad, Kordkuy, Aqqala, Bandar Turkmen, and Bandar Gaz in Golestan province. The study included 84 CPIS beneficiaries who were chosen randomly. Research tool was a questionnaire, and to determine the validity of questionnaire, 5 faculty members of research institutions and centers and several officials involved in irrigation projects and agricultural extension were consulted. The results showed that the most important educational needs of the beneficiaries included pump maintenance, shifting and replacement of irrigation laterals during operation of the system, connecting pumping system to the regulating valve, restoring the pump discharge pressure and flow rate, distributing of soluble fertilizers through the system, removing the notches in the main and secondary pipes and care and maintenance of pump. Also, there was a significant correlation between age, educational level and experience, irrigated acreage of the beneficiaries before installing the system, water extraction rates and educational needs of beneficiaries of CPIS. This study calls attention to preparation of educational courses on classical irrigation systems with emphasis on educational needs of the operators and beneficiaries.
Research Paper
Mansour Ghanian; Masoud Baradaran; Erfanali Mirzaee; Khadijeh Soleymani; Sardar Pasha
Abstract
Due to the importance of water as a basic element of life and its role as a base for development and sustainability of primordial human civilization in different parts of the world, effective management of water is necessary. World experiences and evidence show that governments alone cannot manage water ...
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Due to the importance of water as a basic element of life and its role as a base for development and sustainability of primordial human civilization in different parts of the world, effective management of water is necessary. World experiences and evidence show that governments alone cannot manage water resources successfully. All of the efforts to find the suitable way for this purpose have concluded that optimum management for water systems will be achieved with adoption of an approach that ensures involvement and participation of all stakeholders. The purpose of this study was to investigate views of water users toward participatory management of agricultural water resources and identifying the effective factors affecting it. The collected data of the questionnaire was analyzed with SPSS (quantitative part) and was added to the findings from water users' workshops and reported. Findings showed that water users believed that their participation in evaluation and investigation of social issues in an area and clarification of the tasks expected from them are the most important items in irrigation management plans. Also, the results of factor analysis of farmers' views revealed that technical, legal, and context factors have affected the success of water resource management plans.
Majid Raoof
Abstract
Many forces applied to soil surface during cultivation season cause soil compaction, which affects many soil physical and hydraulic parameters. Under field condition, different forces affect the soil and cause changes in its characteristics. The aim of this study was to determine the effect of soil compaction ...
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Many forces applied to soil surface during cultivation season cause soil compaction, which affects many soil physical and hydraulic parameters. Under field condition, different forces affect the soil and cause changes in its characteristics. The aim of this study was to determine the effect of soil compaction on soil physical and hydraulic properties. Four treatments including T0 (no tractor pass), T1 (one pass), T2 (three passes) and T3 (five passes), were selected. Treatments were irrigated regularly as local farmers’ schedule. After three months, soil samples were taken for determination of some soil properties such as particle and bulk density, shape of cumulative infiltration curve, soil moisture retention curve, and saturated and unsaturated hydraulic conductivity. Water infiltration rate was measured in each treatment using a double ring infiltrometer. Residual water content at a given water pressure head was obtained in laboratory. Inverse solution was used to estimate soil water retention and unsaturated hydraulic conductivity functions parameters by Hydrus 3D code. Results indicated that by increase in the number of tractor passes over the soil surface, bulk density of T1, T2 and T3 treatments increased by, respectively, 17.41%, 26.87% and 35.65% compared to T0. Total porosity of T1, T2 and T3 treatments decreased 16.55%, 25.36%, and 33.04 % and saturated hydraulic conductivity of the same treatments also decreased 38.09%, 59.05%, and 61.43 % compared to T0, respectively. Particle density was constant. Residual moisture, saturated , saturated,and van Genuchten increased, while and decreased due to increase of soil compaction. Soil compaction effect on, , , and parameters was significant, but the effect was insignificant on parameter. Significant probability of these five parameters is different.
Masoud Bakhshayeshi; Morteza Shekarchizadeh
Abstract
Drought stress is one of the most important environmental factors that affect growth, development, and production of plants. To identify drought resistant genotypes and screening the quantitative indices of drought resistance, 23 bread wheat genotypes were tested in a randomized complete block design ...
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Drought stress is one of the most important environmental factors that affect growth, development, and production of plants. To identify drought resistant genotypes and screening the quantitative indices of drought resistance, 23 bread wheat genotypes were tested in a randomized complete block design with three replications. The study was conducted under irrigated and rainfed conditions in the research station of Dryland Agricultural Research Institute (DARI), in Maragheh. Based on the potential (Yp) and stress (Ys) yield, quantitative criteria of drought resistance including mean productivity (MP), tolerance index (TOL), geometric mean productivity (GMP), harmonic mean (HM), stress susceptibility index (SSI), and stress tolerance index (STI) were calculated. The results of mean comparison showed that the highest potential and stress yield were related to the genotypes number 12 and 16, respectively. The highest stress tolerance index (STI), tolerance index (TOL), geometric mean productivity (GMP) and harmonic mean (HM) were related to the genotypes number 16, 17, and 6. The results of correlation analysis between indices, mean potential and stress yield indicated that the most suitable criteria for screening the genotypes under irrigated and rainfed conditions was stress tolerance index (STI). Factor analysis based on principal component analysis method indicated that two important factors accounted for about 99.84% (drought tolerance 73.28% and sensitivity to drought 26.56%) of the total variation among traits in drought and non-drought stress conditions.
Hajar Taheri; Mehdi Ghobadinia; Hasan Tabatabaei; Habib Beygi; Hossein Kazemian
Abstract
Water shortage in agriculture leads to use of marginal water resources such as wastewater. Use of Zeolite as a soil improvement material is necessary for application of wastewater for irrigation. In this research, the effect of application method, amount, and size of the zeolite on the changes of the ...
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Water shortage in agriculture leads to use of marginal water resources such as wastewater. Use of Zeolite as a soil improvement material is necessary for application of wastewater for irrigation. In this research, the effect of application method, amount, and size of the zeolite on the changes of the electrical conductivity, pH, BOD5, sodium, and total calcium and magnesium of wastewater was studied while passing soil columns. To do this, two application methods (mixed and layered), two particle size range of zeolite (between 125 and 63 microns and smaller than 63 microns), two zeolite rates (2% and 4%), and four irrigations (first, fourth, ninth, and thirteenth) were studied in PVC columns of 10.5 cm inner diameter and 60 cm height. The experiments consisted of 9 treatments and 3 replications. The soil samples were irrigated 13 times with wastewater in a weekly interval. In irrigation cycles numbers one, four, nine, and thirteen, the mentioned factors were measured in the input and output of wastewater samples. Results showed that calcium and magnesium absorption rate increased by average of 75.7% and 142% in mixed and layered treatments, respectively, in comparison to the control. Removal efficiency for BOD5 was increased by average of 43.1% and 87% in mixed and layered treatments, respectively, in comparison to the control. Application of zeolite also increased sodium, pH, and electrical conductivity of soil columns.
Research Paper
Nasrdin Parsafar; Safar Maroofi
Abstract
In this study, raw and treated wastewater from the Serkan Wastewater Treatment Plant was reused for potato irrigation under lysimetric conditions. The lysimeters were irrigated systematically each week during a period of five months before sowing operations. Experiment was run within greenhouse during ...
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In this study, raw and treated wastewater from the Serkan Wastewater Treatment Plant was reused for potato irrigation under lysimetric conditions. The lysimeters were irrigated systematically each week during a period of five months before sowing operations. Experiment was run within greenhouse during a period of four months. The experiment was factorial with a completely randomized design in three replicates and two variables: irrigation and soil depth. Irrigation treatments included: raw wastewater (T1), treated wastewater (T2), a combination of 50% raw wastewater and 50% fresh water (T3), a combination of 50% treated wastewater and 50% fresh water (T4), and fresh water (T5) as the control. The soil cores depths studied were 0-10 and 10-20 cm. After harvesting the crop, soil samples of each lysimeter was sampled in order to analyze for cadmium (Cd), nickel (Ni), and lead (Pb) concentration in 0-10 cm and 10-20 cm depths. The results showed that the effects of irrigation treatments were significant on accumulation of Cd, Pb, and Ni in the soil depths. However, the interaction effects were insignificant on accumulation of the heavy metals. According to the results, the maximum and minimum accumulation of Cd, Pb, and Ni in the soil was obtained in T1 and T5, respectively. Overall, based on the accumulation of heavy metals in the soil, the irrigation treatments were ranked as follows: T1> T3> T2> T4> T5. Also, results showed that Cd, Pb, and Ni concentration decreased with soil depth. Based on the accumulation in the soil, the studied heavy metals were ranked as follows: Pb> Ni> Cd.
Research Paper
Sara Mardaninejad; Hamid zare; Hasan Tabatabaei; Abdorahman Mohammadkhani
Abstract
Water stress and the limitation of plants water requirement have different effects on the underground organs growth indices. In this research, the effects of water stress on the growth of long green pepper root were studied in comparison with the regular method of irrigation in the greenhouse conditions. ...
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Water stress and the limitation of plants water requirement have different effects on the underground organs growth indices. In this research, the effects of water stress on the growth of long green pepper root were studied in comparison with the regular method of irrigation in the greenhouse conditions. Irrigation treatments included 4 levels, viz. 40%, 60%, 80%, and 100 percent of the crop water requirement (CWR). At the end of the growing season, the root sampling was done and some of the root indices such as fresh and dry weight, root surface area and volume, length and root length density, and surface area to fresh weight ratio were measured for each treatment and compared with those of the control (100 percent CWR). Duncan's multiple range test showed that, with increasing irrigation water, the weight, volume, surface and root length increased. Therefore, all the studied indices in the 40 % CWR treatment were the lowest in comparison with the control treatment. Besides, in the 80 % CWR, decrease in fresh and dry weight of root was, respectively, 4.7 % and 31 %; in the 60 %CWR, fresh and dry weight decreased 10.5% and 47.7 %, respectively; and in the 40 % CWR treatment, fresh and dry weight of root decreased 25.7 % and 62.5 %, respectively, in comparison to the control treatment. Also, root surface and volume in the 80 %CWR decreased by 9% and 19.8 percent; in the 60% CWR treatment by 16.1% and33.8%; and in the 40 % CWR treatment by 25.8% and 47.3%, respectively, in comparison to the control treatment. The results showed that the root average growth in the control, 80%, 60%, and 40% CWR treatments reached the depth of 50, 48, 43, and 39 cm at the rate of 0.35, 0.33, 0.3, and 0.27 cm/day, respectively. The results of the three stress treatments showed that the reduction ratio of root traits in the 80% CWR was more appropriate compared with the other treatments. These results show savings in water consumption, which is important in terms of economic. Also, in all of the treatments, the amount of root length density decreased with soil depth penetration. In other word, most of the roots density was observed in the surface layer of soil.
Ali Dehghani; Mohammadreza Zare; Amirhossin Tohidi; Mojtaba Nikzad
Abstract
Considering the severe water crisis prevailing in the country, and especially in Kerman province, the objective of the present research was valuation of groundwater in Bahraman region of Rafsanjan. Data of the study was collected by 70 questionnaires in 2011. In order to compute the economic value of ...
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Considering the severe water crisis prevailing in the country, and especially in Kerman province, the objective of the present research was valuation of groundwater in Bahraman region of Rafsanjan. Data of the study was collected by 70 questionnaires in 2011. In order to compute the economic value of water, mathematical programming and shadow price for input of water were used. Moreover, to survey the water’s price at different levels of efficiency by Dalinous method, pistachio orchards were categorized into three groups: small, medium, and large. Then, by using comprehensive data analysis, technical efficiency was calculated for the aforementioned three groups. Results showed that the small orchards were more efficient than the other groups. Therefore, shadow price of water for small, medium, and large groups were estimated at 440, 417 and 315 Toman, respectively, which showed that water was limited in the pistachio orchards. The results also showed that small orchards had higher efficiency and real price of water was high. This indicted that by increase in technical efficiency, the shadow price increases. Thus, proper policies should be adopted to convert traditional pistachio production system to an industrial modern system, thereby preventing the loss of excess water and providing for optimum use of this valuable input. Therefore, government’s support for facilitating installation of drip irrigation systems, provision of extension services, and training farmers to become familiar with the benefits of these systems, which consequently increases the incentive for farmers to apply these systems, is recommended.
Research Paper
Mina Shakiba; Abdolmajid Liaghat; Farhad Mirzaei
Abstract
Effluent disposal and its harmful impacts on environment are an important challenge in drainage projects and environmental problems in Iran. Therefore, by analyzing the flow net and determining the flow paths, efforts must be made to reduce the amount of effluent and improve its quality. This study aimed ...
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Effluent disposal and its harmful impacts on environment are an important challenge in drainage projects and environmental problems in Iran. Therefore, by analyzing the flow net and determining the flow paths, efforts must be made to reduce the amount of effluent and improve its quality. This study aimed to observe the mixing depth as an effective parameter affecting the salinity of effluent. In this experiment, a plaxiglass model was used to investigate the effect of water table head on mixing depth. Mixing depth is the farthermost flow line below the drainage pipe installation depth. At first, KMnO4 and NaCl were added to groundwater supply to increase the salinity of groundwater to 20 dS/m. Then, by using different input discharge and water table head, the variety of mixing depths was determined with photography. Results showed that with increase in the amount of irrigation water, the water table head and mixing depth increased and caused high salinity of the effluent. For instance, by increasing water table head from 8 cm to 23 cm, salinity of the drainage water raised about 80 percent. Finally, the mixing depth was determined as a function of outflow discharge, hydraulic conductivity, depth of impervious layer, and head in the middle of the drainage water. In the next step, the model was validated using observed experimental field data collected from sugar beet development projects in Amirkabir unit located in Khuzestan, Iran. The comparison was done between the salinity that was simulated by the model and the measured value. The results showed the effect of mixing depth on salinity of effluent.
Research Paper
Peyman Afrasiab; Mohammadmehdi Chari; Hossein Hashemzadeh
Abstract
Polyacrylamide (PAM) is a soil additive that increases the absorption of water and nutrients in the soil and provides an appropriate plant growth medium by reducing water losses and the cost of irrigation. In this study, the effect of different amounts of PAM was evaluated in controlling runoff, erosion ...
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Polyacrylamide (PAM) is a soil additive that increases the absorption of water and nutrients in the soil and provides an appropriate plant growth medium by reducing water losses and the cost of irrigation. In this study, the effect of different amounts of PAM was evaluated in controlling runoff, erosion and infiltration on sloping land following two sequential irrigation events. PAM (0, 3, 6, and 9 gr/kg) was applied to a clay loam soil under rainfall simulator in the laboratory. This study was performed on three slopes: 2.5%, 5%, and 10%. The results showed that runoff and soil erosion were reduced when PAM application rate was increased and the reduction in runoff and soil erosion in the second irrigation was much more than the first irrigation. On 5% slope, the maximum reduction in runoff in the second irrigation corresponding to 6 and 9 gr/kg PAM application was 74%. The maximum reduction in soil erosion was 63.8% and 84.3% in the first and second irrigation events, respectively, and belonged to 9 gr/kg PAM treatment. The final soil infiltration rate was increased by increasing PAM application rate in the two irrigation events.