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Hossein Parvizi; Amir Parnian; Hadis Hatami; Mohammad Hasan Rahimian
Abstract
The effects of pressure changes and type of emitter on the performance of pistachio orchard’s drip irrigation systems were studied in 21 orchards, under irrigation by saline water. Based on the results, water distribution uniformity in different parts of the orchards (EU) and the average flow of ...
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The effects of pressure changes and type of emitter on the performance of pistachio orchard’s drip irrigation systems were studied in 21 orchards, under irrigation by saline water. Based on the results, water distribution uniformity in different parts of the orchards (EU) and the average flow of emitters ranged from 71% to 95% and 5.5 to 28.8 l hr-1, respectively. Furthermore, the lowest and highest operating pressure of the emitter were 0.1 and 1.8 bar in different pistachio orchards, respectively. The highest (21%) and lowest (3%) values of coefficient of variation (CV) were obtained from the evaluation of orchards number 13 and 4, respectively. Moreover, the minimum (0.6 %) and maximum (26.2 %) deviation values of the measured average flow from the nominal flow were also observed in orchards No. 3 and 18, respectively. The values of CV in orchards No. 3, 4, 10, 11. 12, 19, and 20 were lower than 10% and were excellent. Orchards No. 2, 13, 14, and 15 with values of about 20% showed good and very good CV, and all of the remaining orchards had very good values of CVs between 10% and 20 %. The results showed that the emitters had a low CV and high EU in the orchards with proper supply and distribution of operation pressure (0.5 to 4 bar) without considering their types and brands. However, the two 8 liters per hour emitters including the Eurodrip and Europlast (King model) for soils with low infiltration rate, and the 26.2 liters/hour Eurodrip emitter for supplying high flow rates with an operating pressure of 0.5 to 1 bar can be recommended. Results indicated that, in most orchards, it is vital to modify the irrigation planning (time and frequency). It seems that if the operating pressure is supplied and distributed properly, emitter clogging and, consequently, EU would not be much affected by water salinity.
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Hossein Beyrami; Mohammad Hassan Rahimian; Farhad Dehghany
Abstract
Water and soil resources of the country are limited, and the optimal use of water resources in agriculture requires estimation of the exact amount of water consumption by different plants in different conditions. This study was conducted to investigate evapotranspiration, crop coefficient, and water ...
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Water and soil resources of the country are limited, and the optimal use of water resources in agriculture requires estimation of the exact amount of water consumption by different plants in different conditions. This study was conducted to investigate evapotranspiration, crop coefficient, and water requirements of salicornia under lysimetric conditions in a factorial experiment with completely randomized design. The experimental treatments were two species of salicornia (Salicornia bigelovii and Salicornia persica) and two levels of irrigation water salinities (8 and 25 dS.m-1) in three replications. The actual evapotranspiration (ETa), reference evapotranspiration (ET0), and crop coefficients (Kc) of salicornia species were determined at three main salicornia growth stages. The results showed that increase in irrigation water salinity from 8 to 25 dS.m-1caused significant changes in yield (biomass and seed yield) of the two salicornia species at the 1-percent probability level. Moreover, the amount of irrigation water consumption in different treatments and replications varied from 28 to 33 thousand cubic meters per hectare. For the salinity level of 8 dS.m-1, the Kc values at the beginning, middle, and end of growing season of bigelovii specie were obtained as 1.18, 1.55, and 1.42, respectively, while for the salinity level of 25 dS.m-1, these values were 1.06, 1.37, and 1.26, respectively. For persica specie, the Kc values of the beginning, middle, and end of the growing season were 1.37, 1.58, and 1.10 (for salinity level of 8 dS.m-1) and 1.15, 1.38 and 1.27 (for salinity level of 25 dS.m-1), respectively. In addition, water use efficiencies of salicornia varied from 0.21 to 0.38 kg.m-3 at different treatments and species.
Rostam Yazdani-Biouki; Mohammad Hsan Rahimian; Gholamhasan Rnjbar; MohammadHadi Rad; Hossein Beyrami; Heidar Meftahizadeh
Abstract
In order to investigate the effect of salinity stress on applied water, yield and water use efficiency of Damask rose, an experiment was conducted based on completely randomized design with three replications and four levels of water salinity including 2.8, 5, 8 and 11 dS.m-1 at Research Greenhouse of ...
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In order to investigate the effect of salinity stress on applied water, yield and water use efficiency of Damask rose, an experiment was conducted based on completely randomized design with three replications and four levels of water salinity including 2.8, 5, 8 and 11 dS.m-1 at Research Greenhouse of National Salinity Research Center, during 10 Oct 2018 to 30 Sep 2019. In this study, volume of applied water and drainage water, evapotranspiration, flower yield, essential oil yield, and water use efficiency (based on flower yield) were determined. The results showed that the average of applied water, evapotranspiration and drainage water in each irrigation were 14.3, 8.4 and 5.9 L per plant for all treatments, respectively. Also, sum of applied water, evapotranspiration and drainage water volume during the experiment were equal to 616, 363 and 253 L per plant, respectively. The sum of irrigation water volume was 619, 625, 610 and 610 L per plant in 2.8, 5, 8 and 11 dS.m-1 treatments, respectively. Flower yield in 2.8, 5 and 8 dS.m-1 treatments were 60.3, 55.8 and 57.1 g/plant and had no significant difference, such that plants treated with 5 and 8 dS.m-1 had a decrease of 7.46% and 5.25% compared to the 2.8 dS.m-1 treatment, respectively. However, treatment of 11 dS.m-1 had the lowest flower yield (22.66 g/plant) with a decrease of 62.42% compared to the treatment 2.8 dS.m-1. The results showed that the highest water use efficiency of Damask rose was obtained in treatments 2.8, 5, and 8 dS.m-1 (0.09, 0.08 and 0.09 kg/m3) and the lowest (0.03 kg/m3) was in salinity of 11 dS.m-1. Salinity stress levels of 8 and 11 dS/m caused the highest percentage of essential oil (0.025% and 0.027%, respectively) and salinity of 2.8 and 5 dS/m caused the lowest percentage of essential oil (0.022% and 0.021%, respectively).
Mohammad Hossein Banakar; Alimohammad Cheraghi; Mehdi Karimi; Mohammadhasan Rahimian
Abstract
Due to shortage of fresh water resources and increase in the salinity of soil and water resources, use of halophytes has a great importance for forage production and human food security. To compare the effect of different irrigation methods (furrow, bubbler, and drip) on some halophyte forage species, ...
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Due to shortage of fresh water resources and increase in the salinity of soil and water resources, use of halophytes has a great importance for forage production and human food security. To compare the effect of different irrigation methods (furrow, bubbler, and drip) on some halophyte forage species, a research was conducted in Sadooq Salinity Research Farm of NSRC in Yazd, Iran, for three years. The experimental design was arranged in complete randomized block design in the form of split plot with three replications, Main plots were different irrigation methods (furrow, bubbler, drip) and halophyte species (A. canescens, A. halimus, A. lentiformis, A. nummularia, and K. indica) were laid out as sub main plots. All plots were irrigated with saline water of 14 dSm-1. During the growing season, all plants were cut every 3-4 months and yield and yield component as well as water use efficiency were measured. Results indicated that A. canescens, followed by A. halimus, with yield of 7.48 and 3.28 ton/ha dry forage, respectively, had the highest forage yield with significant differences (p< 0.05) with each other and with other treatments. Results showed that, under furrow irrigation method, A. canesence and K. indica had the maximum and minimum water use efficiency, respectively. The same trend was also observed for bubbler and drip irrigation methods, as A. canesence had the maximum of water use efficiency under these methods. Based on the results, the highest water use efficiency (2.26 kg/m3) was observed for A. canesence irrigated with bubbler method, and the lowest (0.07 kg/m3) was for K. indica under drip irrigation method. Consequently, based on the results of this experiment and considering the economical and operational aspects of irrigation methods, A. canesence, with dry yield of 7.73 and 8.81 ton/ha under furrow and bubbler irrigation methods, respectively, could be introduced as the best halophyte species for forage production under saline conditions. The results will be more helpful if the experiment is carried out again with determination of water requirement for each plant based on evapotranspiration or soil moisture fluctuations.
mahdi fallah; Mohammad Shayannejad; Mohammad Hassan Rahimian
Abstract
Pistachio is the most important export product of Iranian agricultural sector. This product is very important because of valuation, job creation, value added as well as tolerance to salinity and drought. The purpose of this study was to investigate and analyze the evapotranspiration of pistachio (ETc ...
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Pistachio is the most important export product of Iranian agricultural sector. This product is very important because of valuation, job creation, value added as well as tolerance to salinity and drought. The purpose of this study was to investigate and analyze the evapotranspiration of pistachio (ETc and ETa), gross water requirement (IWR), and depth or volume of water used in pistachios (AW) in several selected gardens in Bahadoran region of Yazd province. The study area is one of the pistachio growing centers in Yazd province. The results show that the total annual irrigation water depth in the selected orchards varies from 823 to 1600 mm (equal to 0.27 to 0.57 L/s/ha). However, due to the salinity of irrigation water and to overcome the problems of accumulation of salts in the soil, the hydromodule necessary to supply the water needed for pistachios varies from 0.6 to more than 1 L/s/ha. According to the critical condition of the water resources in the plain, it is virtually impossible to provide it. Also, by using Surface Energy Balance Algorithm, the actual evapotranspiration of pistachios during the growing season was 556 mm for the whole study area and 672 mm for the selected orchards. Regarding the comparisons between pistachio water demand, actual evapotranspiration, and volume of water used in the selected orchards, a managed deficit irrigation strategy can be recommended for the study area. Optimization of traditional irrigation systems, changes in water utilization system with the aim of reducing irrigation interval, considering the spatial variations of pistachio water requirement in the region, off-season leaching, and implementation of proper management at the orchard level are among the solutions that can be useful in overcoming the salinity and water shortage problems and prevent product loss.
M Dastoorani; S. Poormohammadi; Mohammad Hassan Rahimian
Abstract
Reliable estimation of actual evapotranspiration of the plants plays an important role on planning and optimization of water use especially in dry land environments, where water scarcity is an important problem. In this study, Surface Energy Balance Algorithm for Land (SEBAL) was used for estimation ...
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Reliable estimation of actual evapotranspiration of the plants plays an important role on planning and optimization of water use especially in dry land environments, where water scarcity is an important problem. In this study, Surface Energy Balance Algorithm for Land (SEBAL) was used for estimation of actual evapotranspiration (ETa) in Ardakan pistachio orchards, Yazd province, Iran. For this purpose, a time series of satellite images including 13 cloud free MODIS data were employed to generate actual ET map of pistachio orchards. Results of this study indicated that seasonal ETa for pistachio trees was about 1150 mm, which was significantly less than the applied irrigation depth, Results of this study emphasize the necessity of a proper irrigation scheduling, irrigation interval, and depth in Ardakan pistachio orchards. Consequently, water productivity will improve and considerable amounts of water will be saved as the result of these improvements.
Mohammad Hassan Rahimian; s pourmohamadi
Abstract
Use of Surface Energy Balance Algorithm for Land (SEBAL) and satellite imagery is a relatively new procedure for estimation of actual ET at different scales e.g. farm, catchments and basin levels. This method is based on computation of latent heat flux as the residual of energy budget equation (LE=Rn-G-H) ...
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Use of Surface Energy Balance Algorithm for Land (SEBAL) and satellite imagery is a relatively new procedure for estimation of actual ET at different scales e.g. farm, catchments and basin levels. This method is based on computation of latent heat flux as the residual of energy budget equation (LE=Rn-G-H) and is now used widely around the world, including Iran, for computation of evapotranspiration under standard and non-standard conditions. Azadegan plain is one of the plains that is now faced with waterlogging and salinity problems due to its special topographic, climatic, and hydrologic situations and also due to improper management of its water and soil resources. The main objective of this study was to use the SEBAL to calculate actual ET (ETa) of winter wheat in 2007-2008 cropping season. For this purpose, a seasonal time series of 19 MODIS satellite images and also ancillary climatic data were acquired and used. Finally, time series of daily ETa maps and also a seasonal ETa map were generated and analyzed. Since the crops of the region are under salinity stress, the calculated ETa is an explanatory of crop water requirement under non-standard conditions. The results could help in advising a proper water management plan and also strategies for control and management of salinity and water logging in the region.