majid arabfard; ali shahnazari; Mirkhaleg Ziatabar Ahmadi
Abstract
Introduction: The use of commonly known irrigation methods (especially surface irrigation or even irrigation under pressure) is limited due to the specific physical characteristics of keeping moisture and lowering the water holding capacity. In sandy beaches or desert plains (called sandstones) with ...
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Introduction: The use of commonly known irrigation methods (especially surface irrigation or even irrigation under pressure) is limited due to the specific physical characteristics of keeping moisture and lowering the water holding capacity. In sandy beaches or desert plains (called sandstones) with mentioned physical characteristics. lack of nutrients necessary for plant growth restrict the commonly known irrigation application. Gravity Drip Irrigation (GDI) is a new method that avoids the use of extra energy (pumping station). The total amount of pressure head required by the GDI for fields with a maximum area of 100 hectares is between 1 and 3 meters height. The main purpose of GDI is to reduce the required pressure by the drippers. The utilization of drip tape irrigation as one of the GDI methods has been considered in Iran in recent years. Several studies have been carried out in this regard, each of which pursues specific goals. The GDI benefits includes: reducing water consumption per unit area while increasing the moisture content of the plant root zone, increasing water use productivity, the possibility of irrigation in uneven terrain, reducing weed, pests and diseases damage, ease of distribution of fertilizer, requires lower pressure which consequences to lower cost and energy in the production process. Pot irrigation method is one of the most effective methods for irrigating in these conditions with rough terrain, coarse texture and light soils with high water penetration and saline water which surface irrigation methods normally cannot be used. The application of methods that can provide optimal irrigation conditions for such soils with their specific characteristics, such as delay in water infiltration and low outflow, can lead to improved physical conditions and optimal management of these soils.
Materials and Methods: This research was carried out in the first four months of 2016 in a sandy field located in a part of the agricultural land of Jihad-e-Tavan Co. in Kashan city. In this research, according to the custom of the region, the local watermelon of Sunbek district in Aran and Bidgol city, were chosen as a study plant. A factorial design in a completely randomized block including three main treatments of localized irrigation and three irrigation treatments (total of nine treatments) with three replications, as well as furrow irrigation treatment as control were applied. In each row, 12 plants were planted with a distance of one meter on a row and three meters between rows, on an area of 1080 (36×30) square meters.
Results and Discussion: The role of pulsed irrigation cycle in providing favorable growth conditions and consequently increasing yield can be achieved by comparing the performance of localized treatments and control treatment. The Duncan's test results for number of fruits and yield comparison using selected irrigation methods showed that there was no significant difference in the number of watermelons and their weight at the probability level of 1% and 5%. For different irrigation methods, there was a significant difference between yield and number of watermelons at same probability level. By the end of the 110 days after planting, the yield in furrow irrigation, pot irrigation, drip tape and GDI were 11426, 1224, 7527 and 11457 kg/ha, respectively. The improvement percentage of yield in comparison with the control treatment, were 85%, 1034% and 1626% in pot irrigation, drip tape and GDI, respectively. This research results revealed that the ratio of water used to yield in furrow treatments, pot, drip tape and GDI were 1.18, 5.55, 0.9 and 0.09 m3/kg. Also, considering the amount of water used for each treatment, 49.7 and 23.4 percent decrement in applied water in drip tape and GDI and 371.2 percent increment in applied water in pot irrigation observed per kilograms of watermelon produced compared to the conventional irrigation method (furrow irrigation). Highest water productivity index achieved in GDI among the four methods studied, as much as 1.7 kg of watermelon produced per cubic meter of water.
Conclusion: In this study, the efficiency of more than 80% achieved in furrow irrigation in sandy soil. Improvement in irrigation efficiency in these soils can be achieved by managing parameters involved like furrow length, time and irrigation discharge. The results showed that with the amount of water consumed equal to 6790 cm3/ha in each of the gravity localized irrigation methods and 13452 cm3/ha in the control treatment, the watermelon yield in pot irrigation, gravity drip, drip tape and furrow irrigation methods were 1224, 11457, 7527 and 11426 kg/ha, respectively, and the water productivity index was equal to 0.2, 1.7, 1.1 and 0.8 kg/ha.m3, respectively. In comparison with the one-day irrigation interval, using pulses irrigation in localized irrigation, irrigation efficiency increased from 87% to 98%. In general, by using localized irrigation in comparison with furrow irrigation in sandy soils, in addition to increasing water productivity, high yield could be achieved in plants like watermelon.
M. Arabfard; A. Shahnazari; Mirkhaleg Ziatabar Ahmadi
Abstract
Introduction: Practical problems such as rushing roots toward pot, difficulty of manually filling with water and deficit irrigation due to permeation from regular pots prevents the development of pot irrigation. With regard to increasing irrigation efficiency importance and preventing water loss to fix ...
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Introduction: Practical problems such as rushing roots toward pot, difficulty of manually filling with water and deficit irrigation due to permeation from regular pots prevents the development of pot irrigation. With regard to increasing irrigation efficiency importance and preventing water loss to fix the problems of this irrigation method.Changing physical structure of pot could solve many problems and issues which this irrigation technique is facing. Comparison of the two major characteristics of localized irrigation hydraulic characteristics (coefficient of variation and distribution uniformity) and also using gravity pressure can achieve a solution for water and energy shortage problems. So far, with knowledge of the role of water pressure at gravitational pressures in hydraulicproperties of these methods, some effective features in these methods application is specified.
Material and Methods: This study was carried out in randomized complete block at water engineering department of Sari Agriculture Science and Natural Resources university laboratory from September to December 2015. In this study, in the form of randomized complete block, hydraulic specifications of three treatments of pot irrigation, gravity drip irrigation and porous pipe irrigation investigated under water pressure of 0.5, 1.5 and 3 m. In each of the water column pressure, output water volume from 10 samples of each irrigation method treatments calculated from 7 replicates during one hour in about two months. Porous pipes which used in this study were imported 16mm sample pipes from Anahita Company. GDI gravitational emitter model, porous pipe and containers made of cellulose clay pots in the form of cylinder shape with diameter of 15 cm were used. Thus, within one hour of irrigation, water volume withdrawn from tested samples under constant pressure of irrigation were collected by suitable containers and measured by graded container and flow rate of each samples were calculated. Christensen distribution uniformity coefficient was calculated with Christensen distribution uniformity coefficient formula. Based on USA agronomical engineers, a pointed emitters with variation coefficient less than 0.05 is good, with cv of 0.05-0.10 is medium and with cv of 0.10-0.15 is weak. After calculating evaluation parameters, the results were analyzed with SPSS statistical software and Tukey test at 1 %and 5 % level of probability.
Results and Discussion: The results of statistical analysis of randomized complete block design and mean comparison of different level of treatments effects with Duncan test (irrigation method treatment and water pressure treatment) at 5 %level of probability showed that maximum distribution uniformity achieved in gravitational drip irrigation among samples. With increasing pressure, coefficient of variation was less affected and at lower pressures, coefficient of variation among tested samples were more evident. In addition, it is indicated that increasing pressure have maximum effect on flow rate and distribution uniformity increment while with increasing pressure, minimum changes observed in coefficient of variation. Therefore, among possible gravitational pressures in each project, maximum pressure should be selected for design and implementation. Result showed that in porous pipes and in pressures of 50, 150 and 300 cm, average flow rate were 0.31, 1.4 and 4.2 liter per hour in meter, average coefficient of variation were 0.88, 0.61 and 0.83 and average distribution uniformity were 2.2, 6.2 and 1.6 percent, respectively. In the main-treatment and in each pressure sub-treatment, samples flow rate changes at different replicates is so high that coefficient of variation was more than conventional coefficient (more than 0.6) and thus classified in unacceptable emitters. In this treatment, distribution uniformity was so low that using this irrigation method at gravitational pressures range cannot be recommended. Based on statistical analysis results, it is indicated that increasing pressure in gravitational drip irrigation have maximum effect and in pot irrigation, have minimum effect on flow rate changes, and in addition, maximum distribution uniformity among samples was in gravitational drip irrigation while in porous pipe irrigation besides high coefficient of variation, minimum distribution uniformity among samples were observed.
Conclusion: Due to the high influence of pressure changes in gravitational pressures on hydraulic characteristics of mentioned three irrigation method, among investigated gravitational pressures in this study, pressure of 3m as appropriate pressure at gravitational pressures and among localized irrigation methods, gravitational drip irrigation were recommended. It is recommended to paying attention to the development of gravitational drip irrigation application in large-scale garden and agriculture projects with positive approach.
Mojtaba Cheraghizade; Ali Shahnazari; Mirkhaleg Ziatabar Ahmadi
Abstract
Introduction: According to the Statistical Center of Iran, the country's population between 1957 and 2017, has increased approximately from 19 people to 80 million. With population growth, the water demand is increased and water resources are threatened cumulatively. Agriculture is recognized as the ...
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Introduction: According to the Statistical Center of Iran, the country's population between 1957 and 2017, has increased approximately from 19 people to 80 million. With population growth, the water demand is increased and water resources are threatened cumulatively. Agriculture is recognized as the main water consumer in the country. Due to the arid and semi-arid climate of the country, it is essential to use water reduction strategies such as deficit irrigation (DI) and partial root zone drying (PRD) deficit irrigation in agriculture. In case of water shortages, DI is an optimal solution for production, which is usually accompanied by a reduction in product per unit area. The base of PRD is keeping dry the half of root while irrigating the other half. The plant root in the wet area absorbs enough water. The other part of the root in dry soil, with a reaction to dryness and sending symptoms to the stomata, affects their opening size and reduces water losses. Sunflower is one of the four major oil producing plants in the world. The high volume of this product's import causes the country's strong dependence on oil import and the currency's outflow from the country. Although all living and non-living stresses are considered to be major factors in reducing production, water deficit stress is one of the main factors limiting the production of sunflower; Therefore, studying the reaction of this plant to different drought stress conditions and providing a solution to reduce the negative effects of dryness would be essential.
Materials and Methods: The present study was conducted on sunflower plant (Hysun 25) in a research farm of Sari Agricultural Sciences and Natural Resources University (SANRU) in 27 plots (5 × 5 square meters). Each plot consisted of 6 rows of planting at a distance of 75 cm from each other and 5 meters long. Sunflower seeds were planted at a depth of 4 cm from the soil and at a distance of 20 cm from each other. The experiment was conducted by using split-plot design, with three main factor (irrigation interval) and three sub-factor (irrigation water amount) in randomized complete block design in three replication. The irrigation intervals were irrigation after 20, 35 and 50 mm evaporation from class-A evaporation pan (F-20, F-35 and F-50 respectively). The sub-factor was irrigation water in levels of 100%, 75% and 55% of water demand (FI, PRD-75 and PRD-55 respectively). Controlling the volume of water delivered to each treatment was carried out using a volumetric flow meter. The application of irrigation treatments was carried out six weeks after planting. The irrigation for FI was conducted regularly at both sides of the root and for PRD it alternatively changed at the right and left sides of the root. The studied traits were irrigation water use efficiency (IWUE, kg/m3), height (H, cm), the flower diameter (D, cm), the seeds number per flower (SN), the 1000 seeds weight (W, gr) and the chlorophyll index (SPAD). Statistical analysis of data conducted by SAS software using Duncan test (1% level). Diagrams extracted by Microsoft Excel software.
Results and Discussion: Evaluation of irrigation interval factor based on the experiment two years data, indicated that the best results for plant growth parameters was for F-20. Also, the best results for sunflower plant growth parameters was for FI. According to the significant difference between FI and PRD-55 at most of the growth parameters, it’s suggested to conduct PRD-75 for PRD. For the irrigation interval factor, there was significant difference for most of the plant growth parameters between F-20 and F-50. Therefore, considering this case as well as the problem of increasing the operating cost by reducing the irrigation interval, F-35 is recommended for irrigation interval. It’s concluded that there was significant difference between all of the irrigation interval treatments by analyzing the IWUE trait. The highest amounts was for F-50 and the lowest was for F-20. Despite the increase in the value of IWUE in PRD-75 in comparison with other treatments for each two years of the experiment, this difference was not significant. According to the non-significant difference between F-35 and F-50 for IWUE at the second year of the experiment and this trait relative increase at PRD-75 in comparison with two other treatments, it’s suggested to conduct PRD-75 with F-35 to have higher IWUE.
Conclusion: Simultaneous analysis of sunflower’s IWUE and its growth parameters showed that it could be possible to save in irrigation water use and increase the IWUE with the lowest decrease in the sunflower plant growth parameters by applying PRD-75 and F-35.
Nader Naderi; Ramin Fazl Oula; Mirkhaleg Ziatabar Ahmadi; Ali Shahnazari; Saeed Khavari Khorasani
Abstract
Introduction: Water shortage is the most important factor affecting crop production in the world. The deficit irrigation is a way to reduce water consumption in farming. The Partial Root- zone Drying (PRD) irrigation is a new improvement in deficit irrigation in which the half of the root zone is irrigated ...
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Introduction: Water shortage is the most important factor affecting crop production in the world. The deficit irrigation is a way to reduce water consumption in farming. The Partial Root- zone Drying (PRD) irrigation is a new improvement in deficit irrigation in which the half of the root zone is irrigated alternatively in scheduled irrigation events. In the fixed partial root zone drying (FPRD) the irrigation is fixed to one side of the root zone in the growing season. Maize is a drought sensitive crop. In maize, secondary traits related to drought resistance are considered in producing tolerate cultivars.
Materials and Methods: An experiment was conducted in order to investigate the effects of regulated deficit irrigation, variable partial root zone drying (PRD) and fixed partial root zone drying (FPRD) on the yield, physiological and photosynthetic parameters of forage maize (KSC 704) during the growing seasons of 2014 in Mashhad region. A factorial experiment based on randomized complete block design with four replications was carried out. The treatments included the full irrigation (FI) and the deficit irrigations (regulated deficit irrigation (DI) and the replacements of 80 % (DI80) and 60 % (DI60) of total water requirement, fixed PRD (FPRD) at 100% (FPRD100), 80% (FPRD80) and 60%(FPRD60) of water requirement, and variable PRD at 100% (PRD100), 80% (PRD80) and 60% (PRD60) of water requirement). Drip irrigation tapes were placed between plant rows. In the full irrigation and regulated deficit irrigation treatments, the plants were irrigated from two sides for every irrigation. In the PRD, one of two neighboring tapes was alternatively used for irrigation. In FPRD, a drip tape was used for two plant rows and irrigation was fixed to one side of the root. The irrigation interval was 3 days for all treatments. Dry and fresh forage yield, leaf area index (LAI), stomatal conductance, leaf relative water content (RWC) and chlorophyll content were measured.
Results and Discussions: All the measured traits were affected by the deficit irrigation. The highest fresh forage yield (72099 kg/ha) was produced by the full irrigation treatment. The statistical comparison showed that there was no significant difference between regulated deficit irrigation and PRD method for the fresh forage yield. But the FPRD treatment reduced the fresh forage yield. There was no significant difference between the fresh forage yield of FI and PRD80 treatments. The dry forage yield was affected by the different irrigation methods, irrigation levels and the interaction effects of the treatments (p
M. Sheidaeian; Mirkhaleg Ziatabar Ahmadi; R. Fazloula
Abstract
In this study, impact of climate change on net irrigation requirement (In) and yield of Rice Crop using HadCM3 climate projection model, one of the AOGCM models, in Tajan Plain area is evaluated. Changes in temperature and precipitation were simulated run under the IPCC scenario A2 for 2011-2040, 2041-2070 ...
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In this study, impact of climate change on net irrigation requirement (In) and yield of Rice Crop using HadCM3 climate projection model, one of the AOGCM models, in Tajan Plain area is evaluated. Changes in temperature and precipitation were simulated run under the IPCC scenario A2 for 2011-2040, 2041-2070 and 2071-2100 periods. This work was done by using statistical and proportional downscaling techniques. For estimating Net Irrigation Requirement, Potential evapotranspiration (ETo) and effective rainfall (Pe) were calculated using Penman Monteith equation and USDA method With Cropwat Model, respectively. Impact of water deficit on crop yield was estimated using the linear crop-water production function developed by FAO. The results of downscaling by using SDSM model and proportional method indicate that the decrease in rainfall and increase in the temperature are in future periods. CROPWAT model results indicate that the effect of climate change with increased Potential evapotranspiration and decreased effective Rainfall and increased water consumption of the plant, can be increased, the net irrigation requirement of rice plants in the basin duration years future to come by the year 2100. As a result of climate change and rising temperatures and reduced rainfall, the yield reduction percent to low levels to rise in the coming years. So it can be conclude that the effect of climate change closer to the year 2100 when effective rainfall is less could provide water consumption and net irrigation requirement of rice in the area.
A. Shahnazari; A. Ziatabar Ahmadi; Mirkhaleg Ziatabar Ahmadi; Gh. Aghajani
Abstract
The downward flow to the drain pipe, has a greater influence on the movement of soil particles toward drain envelope as compared with the horizontaland radialflow. In this study, by installing of a singular subsurface drainage systemconsisting of threedrain pipeswith drain spacing of 20 m and drain depth ...
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The downward flow to the drain pipe, has a greater influence on the movement of soil particles toward drain envelope as compared with the horizontaland radialflow. In this study, by installing of a singular subsurface drainage systemconsisting of threedrain pipeswith drain spacing of 20 m and drain depth of 1.5 m, in one hectare field of Sari Agricultural Sciences and Natural ResourcesUniversity, the effects of the elimination of downward flow to the drain pipe was investigated on the water table level and drainage flow. Prevention of direct entry of the vertical flow into drain pipe was performed by placing a layer ofplastic coveron the sand envelope of themiddle drain pipe. Water table level fluctuations were measured in holes which were dug in each drain trench and at 0.5, 1.5, 5 and 10 m spacing apart from each drain at intervals of 5, 15, 25, 35, 45, and 55 meters from collector ditch. Water table depth and drain discharge were measured from April 21 to December 21, 2011. The average drainage discharge fromno plastic drain (drain A) was more than corresponding value for plastic covered drain pipe (drain B) about 12 % and there was a significant difference (p=0.05) between drainage water volume of drains A and B. The average depth of water table levels within the trench of drain A was 9.1 cm more than the corresponding water table depth of drain B. Also, the average depths ofwater table in the 0.5, 1.5, and 5 m spacing apart drain A were approximately 5.2, 2.9, and 0.05 m higher than of thosevalues of drain B. Sediment load of drain A was 74% more than that of drain B,indicating the considerable role of the inflow to drain from its upper part on the consequent sediment transport into drain pipes.
A. Shahnazari; Mirkhaleg Ziatabar Ahmadi
Abstract
One of the important components of suitable operation of subsurface drainage systems is its envelope. Several researchers have evaluated the efficiency of dry land drainage, but the operation of these materials in subsurface drainage systems of paddy fields has not been investigated. In this research, ...
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One of the important components of suitable operation of subsurface drainage systems is its envelope. Several researchers have evaluated the efficiency of dry land drainage, but the operation of these materials in subsurface drainage systems of paddy fields has not been investigated. In this research, the effects of two mineral and artificial envelopes on flow rates of drainage system in paddy fields of Sari Agricultural Sciences and Natural Resources university lands have been investigated. For this purpose, a drainage system consisting of 4 drain lines at 0.65 m depth and 15 m spacing was installed. For two drain lines, mineral envelopes and for other two drains artificial envelopes were used. During one canola growing season, the drain discharges were measured daily. There was significant difference (p=1%) between the mean discharge of drains so that the average drain discharge of drain with artificial envelope was 88 percent higher than the corresponding value of drain with mineral envelope. Based on the drainage water depth-rainfall relationship, the average of daily discharges of drains with artificial and mineral envelopes was equivalent to 2.5 and 1.8 mm rainfall, respectively. Also, comparison of the total costs of the two drainage systems showed that the drainage system with artificial envelope was 30% less expensive than drainage system with mineral envelope.
A. Shahnazari; Mirkhaleg Ziatabar Ahmadi; ghassem aghajani mazandarani
Abstract
Rice is the most important agricultural product in the world after wheat, and Iran has a special place in producing almost two million tones of rice per year. Considering the drought crisis and high consumption of water in paddy fields, it is useful to present strategies in order to increase irrigation ...
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Rice is the most important agricultural product in the world after wheat, and Iran has a special place in producing almost two million tones of rice per year. Considering the drought crisis and high consumption of water in paddy fields, it is useful to present strategies in order to increase irrigation efficiencies. In this respect, many paddy fields in Northern Province of Iran are Land Leveled. The effect of these fields on the Water Balance Parameters, water use efficiency and water productivity has been used in this study. This research has been carried out in Qaemshahr City, Mazandaran Province, comparing two traditional and leveled paddy fields measuring 1.9 and 5.67 hectares, respectively for early-ripening local Tarom species. The water discharge rates of input and output, with 3-inch Parshall Flumes were measured. Three lysimeters were tried in order to determine evapotranspiration and deep percolation. The results demonstrate that in traditional and leveled paddy fields, water use efficiencies turned to be 62.9 and 73%, water productivity of 0.476 and 0.575 kilogram per square meter, evapotranspiration of 468.2 and 477.5 mm, and deep percolation of 196.3 and 147.8 mm, respectively. Also, 25% reduction of deep percolation parameter was observed in land leveled condition which was due to hard pan creation and can be known as the most important factor of 10% increase in irrigation efficiency.
A.R. Jahangir; M. Raeini; M. Ziatabar Ahmadi
Abstract
Abstract
Flood is one of the destructive natural phenomena and being able to forecast it is of great importance. Simulation of rainfall-runoff and flood is difficult due to influence of several factors. So far, different methods have been suggested for their analysis. The aim of this study was to compare ...
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Abstract
Flood is one of the destructive natural phenomena and being able to forecast it is of great importance. Simulation of rainfall-runoff and flood is difficult due to influence of several factors. So far, different methods have been suggested for their analysis. The aim of this study was to compare the efficiency of artificial neural networks (ANNs) in simulating rainfall-runoff process with HEC-HMS model. For this purpose, the Kardeh watershed which is located in northeast part of Great Khorasan province was chosen and based on several precipitation hyetographs and their runoff hydrographs (total of 450 data from 30 selected phenomena) the study was performed. Back-Propagation (BP) algorithm ANN was learnt to the data using sigmoid activation function. The criterion for selecting the network parameters in learning stage was producing the least RMSE in ANN outputs. Based on the SCS method and curve number (CN) the HMS model was performed. To evaluate the ANN performance, the simulated and observed data of total discharge and volume of runoff, peak discharges and peak times were compared. The results showed that based on Delta learning rule the multi layers Perceptron (MLP) network with 29 neurons, simulated the rainfall-runoff process with a high accuracy only in the middle (hidden) layer. The correlation coefficients of the total discharge and volume of runoff were found to be highly significant (r=0.98 and 0.99, respectively). The ANN model could significantly simulate the peak discharge and peak time values (r =0.98 and 0.83, respectively). By analyzing the HMS model performance, the correlation coefficients of the observed and simulated discharges and volumes of runoff were found to be 0.82 and 0.98, respectively. Also, the correlation coefficients of simulated peak discharges and peak times with this model were 0.97 and 0.70, respectively. By performing the T-test analysis at 99% confidence level no significant differences between observed and predicted data was observed. It can be concluded that although no significant differences was found between the two methods, however, the results of evaluated parameters showed that ANN predictions were more precise in comparison with those of HMS model.
Key words: Simulation, hydrologic model, Rainfall-runoff, artificial neural network, HEC-HMS model, Kardeh watershed.
