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.
,fatmeh hashami; Ali Shahnazari; mahmood raeini; ali ghadami firouzabadi; Ebrahim Amiri
Abstract
The research as reported in related to simulation by WOFOST, predominately focused on traditional methods of deficit irrigation such as terms of percentage in full irrigation conditions or as evaluation of growth and development in certain days after irrigation. Also it should be noted that not only ...
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The research as reported in related to simulation by WOFOST, predominately focused on traditional methods of deficit irrigation such as terms of percentage in full irrigation conditions or as evaluation of growth and development in certain days after irrigation. Also it should be noted that not only these researches was based on a year plants, but also there isn’t any research of sunflower. So, in this research the ability of the last version of WOFOST in simulating of sunflower in DI and PRD in %75 and %55 levels is carried out in contrast to FI in two continued year so that crop coefficient of sunflower could be calculated and by this, the productivity of yield in Sari agricultural and natural resources research field could be achieved. The results of calibrations showed that crop coefficient which depends on weather, coordinates of region and physiologic and phonologic of plant is fixed among the simulation and irrigation coefficient are depend on irrigation treatment and their response in development of growth stages. Also the results showed that by decreasing the volume of water which given to plant, AMAXTB and KDIFTB decreased and adversely EFFTB is increase. Simulated seed yield and total biomass had normalized root mean square error (nRMSE) index less than 10%, coefficient of residual mass (CRM) index near zero, modeling efficiency (EF) about 0.98, correlation coefficient (R) about 0.96 and totally comparing the simulation and observation parameters showed that in the most statistical test done in the present study, the result in acceptable range which represented that WOFOST could be able to simulate the responses od sunflower in DI and PRD treatments by calibrated coefficient.
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
S.F. Hashemi; A. Shahnazari
Abstract
Introduction: Water allocation management should be performed in a way that the various practical irrigation parts and drainage networks remain stable. Thus, irrigation management transfer and participatory irrigation management have been proposed in more than 57 countries. Such issue along with institutional ...
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Introduction: Water allocation management should be performed in a way that the various practical irrigation parts and drainage networks remain stable. Thus, irrigation management transfer and participatory irrigation management have been proposed in more than 57 countries. Such issue along with institutional mechanisms for participation severely emphasizes a new adjustable organization to transfer the investment from public resources to non-governmental sources and thus granting and handling the burden on public WUAs. In this study, the reliability of irrigation indicator was used to evaluate general irrigation planning performance of 20 WUAs along areas at Alborz Integrated Water and Land Management Project in Mazandaran province.
Materials and Methods: The overall project area encompassed the watersheds of the BabolRiver, Talar and Saih River of the Mazandaran Province, Iran. The Alborz Irrigation and Drainage network is located in the lower catchment between the Babol and Siah Rivers (western and eastern boundaries respectively) and with the Caspian Sea to the north in. The site located between 36ْ 15َ N and 36ْ 46َ N latitude and 52ْ 35َ E and 53ْ E longitude and covers 90520 ha. In downstream of Alborz reservoir, two diversion dam, Raiskola and Ganjafroz is located and two irrigation channels depends on these dam are constructed.
Organizing the WUAs is also important in other respects, so that the sources and utilization areas will be limited to 2,000 hectares to 6,000 hectares from 10000 hectares to 30000 hectares, respectively, which increases the simulation accuracy in a small-scale model. WUAs are classified based on the following principles:
• Adaptation of hydrological and water boundaries,
• Land use and cropping pattern
• Main and secondary irrigation and drainage channels location,
• Ensuring the financial stability and independence,
• Considering the cultural needs, local farmers’ roles and social studies in the region.
In order to evaluate the water allocation, the reliability index must also be defined which stands as the oldest and most practical criterion for water resource systems analysis serving as the indicator which identifies and analyzes the system status for failure or non-failure condition. In some studies, to determine the reliability index, the entire month in which the system was successful in providing the required water divided by the entire system operation duration. Accordingly, the system can be considered as reliable if the deficiency in not more than 20% in simulation, that is, the probability of 80% can be used to provide the water supply level over four years out of five years. The application of the given method will be used in evaluating the demand balance simulation.
Results and Discussion: The results of estimating the reliability index showed that the water users association with the highest priority in terms of location priority have approximately a reliability index of 70%, representing considerable shortages and deficiency making inevitable use of other resources (BMC1, HATKI1, B3-1-1, TMC1 and RaiskolaWUAs) among which Raiskola had the highest priority relative to other WUAs, with about 91 percent, and was successful in providing the required water. WUAs with lower location priority adjacent to Siahrood River have been successful in approximately 75 percent of their water supply. The WUAs with the lowest priority (HATKI3, TMC3 and BMC3) had the lowest reliability index of about 50% meaning they were successful in meeting the water supply for only 50%. The C24-1 WUAs was 100 percent successful in its water supply which could be also noticeable among other WUAs. In order to assess the success of the system to meet the demand of WUAs, the Alborz network functionality was investigated. The major water utilization from river channels and the release of Alborz Dam were analyzed based on the statistical normal distribution function governing the However, the volume can be varied between160 to 480 million cubic meters. The possibility of 80% supply level (supplying four out of five years) for standing as an example of a guaranteed supply of an irrigation project is about 198 million cubic meters. The probability of 20% of the water supply (a complete supply of a year out of five years) is about 347 million cubic meters. This means that the system is only able to provide an estimate of one year out of five years. The overview of which reveals a considerable value (347 million cubic meters), while from the total surface water flowing in the Alborz network (585 million cubic meters), requirements of Alborz dam supply, environmental needs and output to the sea must be considered. Regarding the 50% probability, the supply value is equal to 277 million cubic meters. Based on the given points and also the conducted analyses, the Alborz network water resources balance results can be estimated. Considering the water resources allocation management among WUAs in Alborz Dam irrigation systems, it was found that among 20 selected WUAss in the area, 5 WUAs of BMC2, B3-2, HATKI3, C25-3 and C25-4 were not able to supply all their needs despite using all resources available in the project.
Conclusion: With aim of minimizing the deficiencies and spatial priorities each one of WUAs were evaluated. Result showed that demand of 460 MCM of WUAs, 277.02 MCM is supplied from surface water. It could be concluded that average reliability is 70 percent and probability of 20 and 80 percent of reliability are 347 and 198 MCM that should be taken into account as total level allocation and first level allocation, respectively. It also could be used to estimate water balance in drought and wet periods, as the application of different management scenarios in withdrawals of AB- bandans and aquifer of Alborz scheme. The results of estimating the reliability index showed that the WUAs with the highest priority in terms of location priority have approximately a reliability index of 60%, representing considerable shortages and deficiency.
A. Shahnazari; M. Rezaiyan
Abstract
Introduction: Deficit irrigation (DI) is a suitable solution to gain acceptable and economic performance by using minimum amount of water. The partial root zone drying (PRD) method introduced in Australia for the first time and its goal was controlling the vine’s excessive growth. This goal gained ...
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Introduction: Deficit irrigation (DI) is a suitable solution to gain acceptable and economic performance by using minimum amount of water. The partial root zone drying (PRD) method introduced in Australia for the first time and its goal was controlling the vine’s excessive growth. This goal gained by alternative drying the rootzone. Basically the theory of PRD method, is expanding the plant’s roots by applying alternative stress on different sides of the roots. So the plants with PRD irrigation method can have different root system in comparison with other irrigation methods. At this method the plant’s condition would be OK by uptaking water from wet side, and the roots at the dry side can release abscisic acid hormone which decrease the stomatal conductance and consequently the water use efficiency would be increase.There had been studies on the effect of water tension on strawberry. The previous studies on strawberry indicated that the water stress can increase the plant’s brix concentration and some of plant acids.The awareness of the impact of water deficit stress on strawberry plant quantity and quality is essential for irrigation and product management, and at the current study, effect of different deficit irrigation methods on quantitative and qualitative traits of strawberry have been evaluated. The focus at the current study was on the qualitative traits.
Materials and Methods: The present study was conducted in one of strawberry farms of Babolsar city in 2012 to evaluate the effects of deficit irrigation and partial root zone drying on quantitative and qualitative traits of strawberry plants. Three Irrigation treatments were studied: Full Irrigation (FI), Regulated Deficit Irrigation (RDI75%) at 75% level of plants water requirementand Partial Root zone Drying (PRD75%) at 75% level of plants water requirement. The study was conducted in a randomized complete block design with three replications. Irrigation was continued until the soil moisture reached to field capacity. The field capacity point’s moisture was measured by using pressure plate equipment. By having the soil moisture curve and measuring the soil suction with tensiometer, the soil moisture situation determined. According to the point that the strawberry’s root is about 25 centimeters (cm), the tensiometers were installed at 2 depths next to the plant. The 1st depth was 8 cm and the 2nd one was 23 cm. The distance between tensiometers and the plant were 4 cm. 2 stochastic replication at the field were considered for the tensiometers positions. In order to deliver precise amount of water to irrigation treatments, the volume counters had been used. The water was applying by using drip tapes. The flow from the emitters on the drip tapes was 2.9 liters per hour. The harvest time was from May 5th to June 20th. To measure the performance, each shrub’s strawberries were weighted separately.Depth of irrigation water during the whole irrigation season for full and deficit irrigation treatments were 341 and 256 mm, respectively. Evaluating the effect of treatments was conducted by measuring the quantitative and qualitative traits of fruits at harvesting time.For analyzing the data, the SAS software and to plot the graphs, the Excel software were used. The SNK test (5% level) was used to comprise the treatments’ traits.
Results and Discussion: Quantitative traits consisted of fresh weight, dry weight, leaf area, leaf area index and yield in FI was higher significantly than deficit irrigation treatments. In comparison with the qualitative traits consisted of titratable acid, acidity and flavor of the fruit there was no significant difference between treatments. The leaf area index (LAI) at RDI and PRD were lower than the FI. Its reason could be the growth’ reducing as a result of abscisic acid (ABA) hormone’s release in the roots which can control the growth. The amount of total sugar (brix) and anthocyanin in RDI were significantly higher than the other two treatments.
Conclusion: The comparison between irrigation treatments indicated that the best quantitative results were at FI treatment. By considering the quantitative and qualitative traits, PRD had the nearest results to FI. At the water stress conditions, applying PRD method at 75% level would be a good management technic to have better performance and increasing the fruit quality. In Mazandaran Province condition, using this method would be a good way to minimize the quantitative losses and increasing the quality of fruits at stress condition.
A. Ghadami Firouzabadi; mahmood raeini; A. Shahnazari
Abstract
Water is the most important factor in agricultural products, water shortage and low irrigation efficiencies in Iran necessitates research in deficit irrigation. This Study to estimate the production function, calculate the depth and optimal index and effect of deficit irrigation on yield was done in ...
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Water is the most important factor in agricultural products, water shortage and low irrigation efficiencies in Iran necessitates research in deficit irrigation. This Study to estimate the production function, calculate the depth and optimal index and effect of deficit irrigation on yield was done in Agriculture and Natural Resources Research Center of Hamadan. Test was performed in Split Plot Design based on Randomized Complete Block in three replications with two factors, containing 1: water deficit irrigation treatment namely, 50, 60, 70, 80, 90 and 100% of basically potato irrigation requirement. 2: Two clones accompanied with Sante Cultivar. The results indicated the effect of different treatment on yield and water use efficiency was significant at the 1% level. Also with increasing water depth until maximum depth, gross income was increased. Also results showed that the net benefit was the same for the equivalent depth under earth limitation and the maximum water depth by 414761192, 84952553 and 91034463 rails for santeh, 397001-13 and 397008-2 clones. The maximum saved water relative complete irrigation belongs to irrigation equal depth under water limitation. It can be concluded that with the savings of water under deficit irrigation practices, the planting area would increase by 21, 27 and 14% for santeh, 397001-13 and 397008-2 clone. The maximum earning return (Rails per m3 of water) under water limitation will be 6080, 12096 and 14185 rails for santeh, 397001-13 and 397008-2 clones. According to 397008-2 clone relative to other cultivars has the highest earning return, so cultivar of this clone than other varieties is recommended.
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.
