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Moazzam Hassanpour Asil; Jamalali Olfati; Mohammadreza Khaledian; Zahra-Sadat Nabavi Mohajer
Abstract
The purpose of the present study was to determine the effect of fertigation with different levels of nutrient solutions and different irrigation regimes on water productivity (ratio of yield to water containing nutrients) in greenhouse lily cultivation. The experiment was conducted in two years at the ...
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The purpose of the present study was to determine the effect of fertigation with different levels of nutrient solutions and different irrigation regimes on water productivity (ratio of yield to water containing nutrients) in greenhouse lily cultivation. The experiment was conducted in two years at the University of Guilan. In the first year, the best treatment was determined among four different concentrations of nutrient solution according to Coic solution including S1, S2, S3, and S4. The results of mean comparison showed that S1 treatment (treatment with the highest concentration of nutrients) had a positive effect on most vegetative, reproductive, and postharvest characteristics of lily. In the second year, with appropriate nutrient solution and three different levels including S11, S12, and S13, different irrigation regimes according to field capacity percent (%FC) were considered. Four different irrigation regimes including 70%, 80%, 90%, and 100% FC were applied. The results of the second experiment showed that application of deficit irrigation treatments including 90%, 80%, and 70% of FC increased water productivity without any significant effects on the vegetative and reproductive characteristics. The results also showed that irrigation treatments had significant effects on traits such as vase life, which was increased by decreasing water consumption and increasing nutrient concentration. Regarding the vegetative characteristics of lily plants, the data showed that traits such as fresh and dry weights of roots, leaves, and flowers were positively affected by decreasing irrigation levels and increasing concentration of nutrient solution, while plant height and both number and weight of daughter bulbs were not affected by these treatments. The highest water productivity (nutrients solutions) was obtained in the S3 and 80% FC, being 21.57 kg/m3.
Farshad Khashaei; Javad Behmanesh; Vahid Rezaverdinejad; Nasrin Azad
Abstract
Use of subsurface drip irrigation (SDI) in row plants is increasing due to higher water and fertilizer efficiency. In order to investigate the effect of SDI levels and nitrogen fertilizer splitting on yield, yield components and water productivity of corn, a field study was conducted in 2018 as split ...
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Use of subsurface drip irrigation (SDI) in row plants is increasing due to higher water and fertilizer efficiency. In order to investigate the effect of SDI levels and nitrogen fertilizer splitting on yield, yield components and water productivity of corn, a field study was conducted in 2018 as split plot experiment based on a completely randomized block design with three replications at the research farm of Urmia University. The main plots of this experiment including three irrigation levels: 100%, 75% and 50% of net irrigation requirement and subplots included three nitrogen fertilizer split applications as: weekly, every other week and three times during growing season as urea fertilizer. Based on the results, the effect of irrigation levels treatment and number of fertilizer splitting on yield, yield components and water productivity were significant at 1% level. However, the effect of fertilizer splitting on water productivity was not significant. Interaction effects of the two variable treatments on plant height and leaf area index were significant at 1% level but did not significantly affect grain yield, biomass and water productivity. The highest grain yield and corn biomass were obtained with 22.39 and 39.85 ton/ha for complete irrigation, respectively. Also, the grain yield and biomass in the three- split treatments were highest with 18.47 and 32.56 ton/ha, respectively. The highest water productivity was obtained by irrigation application of 75% of net water requirement. It seems that in regions with water scarcity, applying deficit irrigation equal to 75% of the corn irrigation requirement, can be a good solution for saving water and achieving high water productivity. Also, fertilizer injection with higher amounts and less frequency especially at the sensitive growth stages, can be a more effective solution than using lower amounts with more frequent fertilizer application.
M S; M.B N; SH K; N N
Abstract
For the proper use of water resources in agriculture, it is necessary to provide appropriate irrigation system to supply crop water requirement. In the present research, using a hierarchical analysis, different types of irrigation systems were evaluated and prioritized on 1150 hectares of agricultural ...
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For the proper use of water resources in agriculture, it is necessary to provide appropriate irrigation system to supply crop water requirement. In the present research, using a hierarchical analysis, different types of irrigation systems were evaluated and prioritized on 1150 hectares of agricultural land of Etka Organization located in Dorud, Iran. Hierarchical analysis process is one of the multi-criteria decision making techniques that can be used in different sciences. This method can enter effective qualitative and quantitative factors systematically into the decision-making model. At the first step of this research, the structure of the decision problem was designed and then different options were compared based on the criteria in decision making. Finally, the irrigation methods were prioritized. The results showed that in the case of furrow, sprinkler, and drip irrigation systems, sprinkler systems had priority over the other methods. At the end of the study, zoning of sprinkler system in the study area was designed and shown in maps.
m k
Abstract
Evapotranspiration is one of the most important components in the optimization of water use in agriculture and water resources management. In recent years, artificial intelligence methods and wavelet based hybrid model have been used for forecasting of hydrological parameters. In the present study, applications ...
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Evapotranspiration is one of the most important components in the optimization of water use in agriculture and water resources management. In recent years, artificial intelligence methods and wavelet based hybrid model have been used for forecasting of hydrological parameters. In the present study, applications of the adaptive network-based fuzzy inference system (ANFIS) and Wavelet-ANFIS models to forecast weekly reference evapotranspiration at the synoptic stations of Tabriz, Ahvaz, Bandar Abbas, and Ramsar were investigated. For this purpose, a 20-year statistical period (1990-2009) was considered: 15 years (1990-2004) for training and the final five years (2005-2009) for testing the various models. Various combinations of input data (various lag times) and different kinds of mother wavelets were evaluated. Results showed that, compared to the ANFIS model, the hybrid model Wavelet-ANFIS had greater ability and accuracy in forecasting weekly evapotranspiration at all of the four synoptic stations. Moreover, the use of yearly lag times in the ANFIS model increased its accuracy. However, in the Wavelet-ANFIS, yearly lags not only did not increase the accuracy of the Wavelet-ANFIS model, but also reduced its accuracy in some cases. Investigation of various kinds of mother wavelets also indicated that the Meyer wavelet was the most suitable mother wavelet for forecasting weekly reference evapotranspiration. Results of this study can also be used for irrigation scheduling in the studied regions.
bakhtiar karimi; parva mohammadi
Abstract
One of the most important parameters in designing, managing, and operating surface and subsurface drip irrigation systems is the advance velocity of the wetting (moisture) front in soil, which enormously affects the performance of these systems. Emitter discharge, soil type (soil texture and structure) ...
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One of the most important parameters in designing, managing, and operating surface and subsurface drip irrigation systems is the advance velocity of the wetting (moisture) front in soil, which enormously affects the performance of these systems. Emitter discharge, soil type (soil texture and structure) and initial moisture content are the main factors affecting advance velocity under drip irrigation. Experiments were carried out in a transparent plexiglass tank (0.5 m*1.22 m*3 m) using three different soil textures (light, heavy, and medium). The drippers were installed at 4 different soil depths (surface, 15 cm, 30 cm, and 45 cm). The emitter outflows were considered 2.4, 4, and 6 L/hr. A simulation model was developed using artificial neural network (ANN) for predicting advance velocity of the wetting front (horizontal, downward, and upward direction) under point sources in surface and subsurface drip irrigation. The variables affecting wetting pattern included emitter discharge, emitter installation depth, application time, saturated hydraulic conductivity, soil bulk density, initial soil moisture content, and the proportions of sand, silt and clay in the soil. The results of the comparisons between the simulated and measured values showed that the ANN model was capable of predicting the advance velocity of the wetting front in different directions with high accuracy. The values of Root Mean Square Error (RMSE) varied from 0.09 to 0.35, from 0.02 to 0.17, and from 0.08 to 0.25 cm/min for horizontal, downward and upward velocity, respectively. Also, the values of Mean Absolute Error (MAE) varied from 0.06 to 0.27, from 0.02 to 0.07, and from 0.05 to 0.12 cm/min for horizontal, downward, and upward velocity, respectively. Using these models in designing and operating surface and subsurface drip irrigation systems could improve system performance.
Mohammad Karimi; Masoud Ghodsi
Abstract
Effects of different irrigation levels on yield, water consumption, water use efficiency, and agronomic characteristics of cotton-wheat crop rotation were examined in the temperate zone of Khorasan Razavi. The study was conducted in Gonabad Research Station, using split-split plots based on randomized ...
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Effects of different irrigation levels on yield, water consumption, water use efficiency, and agronomic characteristics of cotton-wheat crop rotation were examined in the temperate zone of Khorasan Razavi. The study was conducted in Gonabad Research Station, using split-split plots based on randomized complete block design with three replications, in 2015-2016. Three tillage methods (no-till, conventional tillage, and reduced tillage) were in the main plots, three residue managements (without residue, 30% of the residues and 60% residue) in sub plots, and three levels of irrigation water (50%, 75% and 100 percent of the water required according to the National Water Document) were in sub-sub plots. Parsi wheat cultivar was used for cultivation. The results showed that the highest (non-significant) grain yield of wheat was obtained from no-tillage and without residue treatment. It was determined that no tillage and direct cultivation resulted in increased wheat grain yield and could be recommended economically, since it would reduce production costs. However, keeping or removing plant residues did not have a significant effect on yield, although the positive effects of plant residues on the improvement of soil properties and, consequently, on the yield of crops in the medium to long term are evident. The highest wheat yield (6249 kg/ha) was obtained from no-tillage with 30% residue and 100% of the water requirement. The highest water use efficiency of wheat (1.57 kg/m3) was obtained in no-tillage, without residue and 50% of the water requirement. The highest yield of wheat was recorded in the full irrigation (100%) treatment and was significantly different from other irrigation treatments (75%). By applying 50% of the water requirement, wheat yield decreased by 36.3% and by applying 75% of the water requirement wheat yield dropped by 31.5%. As a result, it is possible to save water consumed by wheat under a conservation agriculture system because water productivity increased in comparison with the conventional agricultural system.
J B; N A; M M; S B
Abstract
Comparison of Linear and Nonlinear (Bilinear) Time Series Models in Reference Crop Evapotranspiration Prediction in Urmia Synoptic StationReference crop evapotranspiration (ETo) prediction is one of the important elements in optimizing agricultural water consumption. In this regard, one of the prediction ...
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Comparison of Linear and Nonlinear (Bilinear) Time Series Models in Reference Crop Evapotranspiration Prediction in Urmia Synoptic StationReference crop evapotranspiration (ETo) prediction is one of the important elements in optimizing agricultural water consumption. In this regard, one of the prediction approaches is to use the stochastic time series methods. In this research, AR (p) and ARMA(p,q) linear models and Bilinear nonlinear model were compared in predicting the monthly values of ETo in Urmia synoptic station. To conduct the present research, the monthly values of ETo from 1971 to 2010 were calculated and data between 1971-2005 and 2006-2010 were used for models calibration and validation, respectively. In the next step, the suitable linear model was selected and the results of this model and Bilinear nonlinear model were compared with the values of FAO Penman-Monteith method. The results showed that the AR(11) time series model had better results than the other linear models. The comparison of the results of AR(11) model and BL(11,0,1,1) model with the monthly values of the ETo using FAO Penman-Monteith method showed that the value of root mean square error (RMSE) and relative error (VE) in AR(11) model were 1.85 mm and 3.8 %, respectively, and in BL(11,0,1,1) model, they were 1.76 mm and 3.6 %, respectively. Therefore, Bilinear nonlinear model had more capability in modeling and predicting of the monthly values of ETo values in comparing with linear models. In the next step, the monthly values of ETo for five future years were predicted by using the Bilinear nonlinear model.
m m; a m; a v
Abstract
In the present study, hydraulic properties of low pressure drip irrigation systems in lateral pipes were evaluated by mathematical model with the aid of experimental data resulting from testing of tubes available in Iran. In this regard, emitters discharge were measured in different initial heads from ...
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In the present study, hydraulic properties of low pressure drip irrigation systems in lateral pipes were evaluated by mathematical model with the aid of experimental data resulting from testing of tubes available in Iran. In this regard, emitters discharge were measured in different initial heads from 0.45 to 1.8 m for laterals with outside diameter of 32 mm with different lengths of 89, 60, 30, and 16 meters and also for laterals with the length of 16 meters and external diameters of 32, 25, 20, and 16 mm. the obtained discharge-head relation was q=1.955h0.8421 with R2 of 0.93. On the basis of the ratio of lateral diameter to its length, two relations were proposed for estimating local loss as a function of Reynolds number with R2 of 0.95 and 0.75. Furthermore, experimental results showed that Colebrook-White relation could be used as a good estimation for friction losses. The model was calibrated and evaluated using experimental data and relations which were obtained from experimental results. The model was used for evaluating the effect of different heads, lateral diameters, and length on emitter discharges, which was not possible to evaluate experimentally. The results revealed that the proper length interval in which the uniformity is more than 80% was 40 to 75 meters for laterals with the external diameter of 16 mm under different heads (from 0.45 to 1.8 meters). This length interval for laterals with external diameters of 20, 25, and 32 mm was 50 to 100 m, 70 to 150 m, and 80 to 180 m, respectively. Finally, a relation was developed for designing low pressure drip irrigation system.
h a; h b; Hossain ebrahimi
Abstract
Salinity is considered as one of the main problems affecting the growth and yield of many plants. Salinity tolerance varies with the amount of nitrogen uptake. The aim of the study was modeling the response of tomato (Solanum lycopersicum) under simultaneous salinity and nitrogen deficiency stresses. ...
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Salinity is considered as one of the main problems affecting the growth and yield of many plants. Salinity tolerance varies with the amount of nitrogen uptake. The aim of the study was modeling the response of tomato (Solanum lycopersicum) under simultaneous salinity and nitrogen deficiency stresses. The indoor pot experiment was conducted in Damavand region, Iran, in 2015. The experiment was carried out on tomato plant in a factorial randomized complete block design with 3 replications. The treatments consisted of six levels of salinity (1, 2, 4, 6, 8 and 10 dS/m) and three levels of nitrogen including zero, 50 and 100 percent of the N-fertilizer needs. The maximum dry matter yield (25.8 gr) was obtained in the treatment with salinity of 1 dS/m and fertilizer consumption of 100%, while the minimum dry matter yield (5.8 gr) belonged to the treatment with salinity of 10 dS/m and no fertilizer application. Modified Liebig-Sprengel (LS) and Mitscherlich-Baule (MB) models were used to evaluate tomato response to nutrients. Comparison of statistics showed that for modeling tomato plants response to simultaneous salinity and nitrogen stresses, modified MB model (d=0.95) fitted better to the measured data compared to modified LS model (d=0.88). Therefore, modified MB model was recommended to estimate relative yield of tomato. Also, results showed that, at a fixed salinity level, by increasing amount of nitrogen application, the yield of dry matter was increased, while yield of dry matter decreased with increasing salinity. Threshold of yield decline in saline conditions is not fixed and depends on the amount of nitrogen in the soil. Decline of relative yield with increase in salinity wasn’t significant in zero-nitrogen treatment, which showed the influence of nitrogen deficiency relative to salinity. Therefore, threshold of tomato yield decline could be increased by nitrogen fertilizer management.
a yadollahi; n teymouri; v abdousi; s sarikhani
Abstract
Considering the arid and semi-arid conditions in Iran, with average rainfall of less than 247mm, development of rainfed orchards has an important role in sustainable development of agriculture. To establish rainfed orchards in Iran in spite of deficiency in water resources, it is necessary to select ...
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Considering the arid and semi-arid conditions in Iran, with average rainfall of less than 247mm, development of rainfed orchards has an important role in sustainable development of agriculture. To establish rainfed orchards in Iran in spite of deficiency in water resources, it is necessary to select suitable plant species and methods of establishing new orchards. Therefore, this study was conducted to evaluate some almond cultivars (Shahrood 7, 10, and 12) and integration of microcatchments and Stockosorb Superabsorbent for establishing rainfed orchards during 2008-2010. The use of Superabsorbent with microcatchment increased relative moisture content of soil in both years. But, in the first year, there was no significant difference between microcatchment treatments with and without Superabsorbent, while both of them showed significant difference with the treatment of Superabsorbent without microcatchment. In the second year, the highest relative moisture content of soil was in microcatchment treatment with Superabsorbent, because of higher seasonal rainfall that caused more vegetative growth in the young almond trees in that treatment compared to the other treatments. Among the almond cultivars studied, Shahrood 7 and 12 seemed more resistant and adaptable to dry conditions than Shahrood 10 cultivar, because of their better vegetative characteristics.
Samira mesry; Shoja Ghorbani; Hossin Shirani; Abolghasem Kamkar; hamidreza motaghian
Abstract
Soil water is an important factor in the growth of the plant. There are different methods for soil moisture estimation. It is time-consuming to obtain volumetric soil moisture in a laboratory. This study was performed to evaluate estimate of soil moisture by different in situ methods including the electrical ...
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Soil water is an important factor in the growth of the plant. There are different methods for soil moisture estimation. It is time-consuming to obtain volumetric soil moisture in a laboratory. This study was performed to evaluate estimate of soil moisture by different in situ methods including the electrical resistance of Werner electrode arrangement and ground penetration radar (GPR) from 700 MHz antenna, and two humidity sensors, namely, thetaml2 and sm300. These were used in 72 soil samples with different textures (loam, sandy clay loam and silty loam, silty clay, silty clay loam, clay loam) in parts of Shahrekord Watershed.The results showed that the coefficient of correlation between soil moisture and electrical resistance was 0.85. Also, the correlation coefficient between the values obtained from subsurface radar method, sm300 sensor and thetaml2 with the results obtained from laboratory measurements were 0.86, 0.94, 0.86, with CRM index values of -0.52, -0.75 and –1.22. By comparing the results of electrical resistivity, moisture from the GPR and the sm300 and thetaml2 sensors with volumetric moisture, the Root Mean Squared Error (RMSE) values were 8.41, 4, 5.3 and 8.6; and RRMSE were 10, 31, 29, and 26, respectively. Duncan test of moisture content showed that the difference between the sensors and the laboratory moisture content was significant at 5% level (p<0.05). According to the value of RRMSE All sensors had a good estimate of soil moisture. In conclusion, electrical resistivity and GPR method, due to higher sampling density, could be used as a rapid, cost effective, and non-destructive technique to estimate profile of soil water content at scales of field to sub-watershed.
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Zahra Ghafarimoghadam; ebrahim moradi; mahmoud hashemi tabar; Ali Sardar Shahraki
Abstract
The purpose of this study was to gain a better understanding of the future of water in the agricultural sector of the Sistan region. In this study, to determine the final drivers, we relied on Future Studies techniques and, by using the Expert Panel method, 23 drivers were identified and seven main drivers ...
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The purpose of this study was to gain a better understanding of the future of water in the agricultural sector of the Sistan region. In this study, to determine the final drivers, we relied on Future Studies techniques and, by using the Expert Panel method, 23 drivers were identified and seven main drivers affecting the Sistan water crisis were used to write the scenarios by Delphi method. These factors included drought, dependence on external water resources, the lack of sufficient attention to water resources management, careless cultivation of crops with high water requirement, inappropriate irrigation methods, technological weakness of agriculture, and free water charges in the agriculture sector. Also, 86% of the Sistan region will be exposed to a severe water crisis in the future according to the hazard zonation map. Furthermore, probable conditions for each of these factors were presented, and using that, 3 scenarios with high acclimatization include the first, second, and third scenarios for the water crisis in Sistan, which were designed using the Wizard Scenario software. In these scenarios, three situations including: possible state (if the drivers remain in the current state), optimistic state (improvement of the condition), and pessimistic state (weakening of the condition) were designed for each of the factors. Cultivation of crops with high water requirement were in a pessimistic state, free water and drought in a possible state, and the other drivers in an optimistic state. In these scenarios, optimistic conditions were superior to others and formed most of the assumptions. It is expected that these scenarios would improve water and agricultural conditions in the Sistan Plain.
moazam khaleghi; Ali Shahnazari; farzad hasanpour; F K
Abstract
The scarcity of freshwater and increasing water demand for irrigation has led to the application of new irrigation methods and also use of saline water resources. For this purpose, a field study was conducted in two crop seasons (2014 and 2015) for evaluating the effect of quantity and quality ...
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The scarcity of freshwater and increasing water demand for irrigation has led to the application of new irrigation methods and also use of saline water resources. For this purpose, a field study was conducted in two crop seasons (2014 and 2015) for evaluating the effect of quantity and quality of irrigation water on morphological attributes and quality of sunflower in the experimental farm of Sari Agricultural Sciences and Natural Resources University. Treatments were arranged as factorial based on randomized complete block design with three replications. treatments included full irrigation with fresh water (FI), full irrigation with saline water (SI), full irrigation with alternative use of saline water and fresh water (FSI), partial root zone drying irrigation with fresh water (PRD1), partial root zone drying irrigation with saline water (PRD2) and partial root zone drying irrigation with alternative use of saline and fresh water (PRD3). Saline water with an electrical conductivity of 5.4 dS/m was obtained from 20 percent mixing of Caspian seawater with fresh water. The results showed that, in most morphological characteristics, significant difference was not found between the treatments of PRD1, PRD3 and FSI compared with FI. The highest oil content (56%) was obtained from PRD2 and PRD3. SI treatment had the lowest oil content. The maximum oil yield was found in treatments FI and PRD1 with amounts of 1831 and 1783.5 kg per ha, respectively. The lowest level of oil and protein yield was found in PRD2 and SI treatments in both years. It could be concluded that in the water crisis condition and the need to use less water or saline water instead of fresh water, PRD3 and FSI methods are recommendable as the optimal management.
M Y; S B; Z I; H S
Abstract
Accurate estimation of evapotranspiration plays an important role inquantification of the water balance at regional scale for better planningand managing water resources. Evapotranspiration can be obtained fromeither estimation of potential ET using data of meteorological stations or,directly, from field ...
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Accurate estimation of evapotranspiration plays an important role inquantification of the water balance at regional scale for better planningand managing water resources. Evapotranspiration can be obtained fromeither estimation of potential ET using data of meteorological stations or,directly, from field measurements. ET is subject to rapid changes in timeand space, attributable to the wide spatial variability of precipitation,hydraulic characteristics of soils, and vegetation types and densities.Therefore, it is nearly impossible to determine its spatial and temporaldistributions over large areas only from lysimeter and precise measuringinstruments. Thus, researchers have used remote sensing data to estimateareal actual ET. In this study, actual evapotranspiration variations ofNeyshabour plain was investigated by algorithm of energy balance of theearth since 2000 to 2013 by using MODIS images and meteorologicaldata. Also, the determined evapotranspiration was compared and evaluatedwith Penman-Monteith and Hargreaves-Samani models. Low amount ofcoefficients of the error between Penman-Monteith model and SEBALalgorithm showed the accuracy of SEBAL model in the estimation ofevapotranspiration and its parameters. The results derived fromcomparison of evapotranspiration and NDVI vegetation index indicated agood correlation between vegetation and evapotranspiration (R2=0.908).Also, the variations of NDVI index, land surface temperature, andevapotranspiration in the studied fields showed that evapotranspirationincreased by lower land surface temperature and higher densities ofvegetation.
y h; m gholami; v soltani
Abstract
When irrigating with saline water, salt distribution pattern within the root zone is affected by leaching fraction and crop water uptake pattern, in addition to the chemical interactions of soil solution. In order to evaluate leaching requirement and sensitivity of alfalfa to salinity, a lysimetric study ...
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When irrigating with saline water, salt distribution pattern within the root zone is affected by leaching fraction and crop water uptake pattern, in addition to the chemical interactions of soil solution. In order to evaluate leaching requirement and sensitivity of alfalfa to salinity, a lysimetric study (cylindrical lysimeters with internal diameters of 40cm and height of 180 cm) was conducted in completely randomized design with 3 levels of irrigation water salinity (3, 7 and 13 dS/m) and 3 levels of leaching fractions (12%, 25%, and 50 %) as a factorial experiment with 4 replications. After packing, soil columns were leached until drainage water salinity reached 3 dS/m and, then, were sown with alfalfa (Yazdi cultivar). To prepare different irrigation water salinity, natural saline water from Sadouq Salinity Research Field with salinity level of 14 dS/m was blended with tap water in different ratios. The amount of applied water was based on crop water consumption in addition to leaching fraction which was carefully weighed. The collected drain water was weighed again after 48 hr in which drain water quality was measured too. The least required irrigation cycles to reach steady state conditions was 12 cycles which increased with increasing salinity level and decreasing leaching fraction. Generally, results showed that implementation of a defined leaching fraction can reduce soil salinity more than WatSuit predictions. Therefore, soil salinity control at a desired level can be obtained with less leaching fraction level. This is especially important for optimum water utilization under saline conditions when irrigation is linked to application of more salts.
f g; s f; a t
Abstract
The trend of saline water utilization in agricultural production is increasing. In order to evaluate the effect of source and rate of nitrogen on physiological characteristics of purslane (Portulaca oleracea L.) irrigated by saline water, a factorial experiment was conducted in a completely randomized ...
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The trend of saline water utilization in agricultural production is increasing. In order to evaluate the effect of source and rate of nitrogen on physiological characteristics of purslane (Portulaca oleracea L.) irrigated by saline water, a factorial experiment was conducted in a completely randomized design with three replications in the greenhouse conditions. Treatments included five levels of saline water (distilled water as the control, natural saline water with EC of 2.2 dS/m, three levels of saline water prepared by addition of NaCl (2.2, 4.4, and 6.6 dS/m) and four levels of fertilizer (control, 40, 80, and 120 g/kg soil) in the form of poultry manure and chemical fertilizer. The results showed that an increase in salinity increased chlorophyll a and chlorophyll b and then decreased them at 6.6 dS/m. An increase in salinity levels increased the amount of sodium and decreased the amount of potassium. The maximum amount of chlorophyll a and chlorophyll b were observed with 4.4 dS/m treatment. The interaction of salinity level × nitrogen source × nitrogen rate was not significant for any of the measured parameters. Results of poultry manure were better than those of chemical fertilizer, because chlorophyll content, soluble sugar, proline, sodium, and potassium in purslane plant were higher. Thus, the plants fertilized with poultry manure or those irrigated with natural saline water experienced salinity stress, but their higher uptake of potassium alleviated the stress effects and made it tolerable for the plant.
yaser hossini; Javad Ramezani Moghaddam; Mohammad Reza Nikpour; Attieh Abdoli
Abstract
Various mathematical models are available for predicting the response of plants to combined water and salinity stress and their share in water uptake. The reduction functions are classified as additive, multiplicative, and conceptual models. In this study, 6 macroscopic reduction functions, namely, Van ...
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Various mathematical models are available for predicting the response of plants to combined water and salinity stress and their share in water uptake. The reduction functions are classified as additive, multiplicative, and conceptual models. In this study, 6 macroscopic reduction functions, namely, Van Genuchten (additive and multiplicative), Dirksen et al., Van Dam et al, Homaee and Skaggs were evaluated in a greenhouse experiment on cherry tomato, var. cherry tomato cluster. This experiment was performed based on a completely randomized design with 3 replicates and 2 levels of salinity (4 and 7 dSm-1). Water stress levels were imposed as matric potential decline during the study at 3 levels of available water depletion (40%, 50%, and 65%). The result of the study indicated that the crop response to water stress and salinity stress was incremental at 4 and 7 dSm-1 salinity levels. Among the multiplicative models, reduction functions of Dirksen model had better fit than others at 4 dSm-1 salinity level (RMSE=0.15 and ME=0.14).However, at 7 dSm-1, Van Dam (RMSE=0.017, ME=0.09) and Skaggs (RMSE=0.018, ME=0.14) had better fit to the measured data.
halime piri; Abolfazl Bameri
Abstract
In this research, the effect of different levels of irrigation water, nitrogen fertilizer, and cow manure on garlic was investigated. The experiments were carried out in a split-spilt plot design, with four levels of irrigation water depths (40%, 60%, 80% and 100% of the plant water requirement) in the ...
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In this research, the effect of different levels of irrigation water, nitrogen fertilizer, and cow manure on garlic was investigated. The experiments were carried out in a split-spilt plot design, with four levels of irrigation water depths (40%, 60%, 80% and 100% of the plant water requirement) in the main plots, three levels of nitrogen (50, 75 and 100% nitrogen) in the sub- plots, and three levels of manure (25, 32.5 and 50 ton/ha cow manure) in the sub-plots. Nitrogen was applied in two stages and cow manure in one stage before planting. At the end of the experiment, parameters such as plant height, weight, and number of garlic, yield, and irrigation water productivities were measured. The results showed that the effects of irrigation water, nitrogen fertilizer, and manure were significant (p< 1% and <5%) on all parameters. The highest yield was obtained from 100% fertilizer application and 100% water requirement, but no significant effect was observed between treatments of 100 and 80% of water requirement. The highest amount of irrigation water utilization was obtained at irrigation level of 60% and fertilizer level of 100% (1.48 kg/m3/ha). In this regard, there was no significant difference between treatments of 60% and 80% of water requirements. The amount of allicin was reduced by reducing irrigation water and reducing fertilizer use. Increasing nitrogen fertilizer up to 75% of fertilizer requirement, amounting to 150 kg/ha, resulted in increase of allicin, but higher amounts resulted in decrease of allicin content. Therefore, due to shortage of water in the region, irrigation of this crop can be done with 80% of the plant's water requirement, without a significant effect on the yield.
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).
H GHAMARNIA; Milad farmanifard; SH SASANI
Abstract
Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants ...
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Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants water requirement. Therefore, a two-year experiment was conducted in 2009-2011 to find the effect of shallow groundwater tables, at 60, 80, and 110 cm depth, on water requirement, water use efficiency (WUE) and yield of three wheat cultivars, namely, W33g, Cross Alborz, and Bahar. Experiments were performed at RaziUniversity lysimeter research station No1 as a randomized complete block factorial experiment with three replications. In these experiments, 45 tubular poly ethylene lysimeters with 1.20m height and 0.30m diameter were fixed in the ground with 1m distance from each other. The highest utilization of groundwater was found for the water table depth of 60 cm and the lowest was found for the 110 cm depth. The 2-year average contribution to different cultivars by groundwater in depths of 60, 80, and 110 cm was 63%, 55% and 45%, respectively. The results for Cross Alborz cultivar showed no significant difference (P<0.01) in WUE between the three water table depth treatments. Overall, the optimum WUE and yield was found at water table depth of 80 cm.
Abstract
Pistachios are salt tolerant crops, but the degree of salt tolerance of pistachio cultivars grown in northern parts of Yazd province, Iran, is not adequately known. In order to evaluate the effect of saline water on the growth and chemical composition of pistachio seedlings, a glasshouse experiment was ...
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Pistachios are salt tolerant crops, but the degree of salt tolerance of pistachio cultivars grown in northern parts of Yazd province, Iran, is not adequately known. In order to evaluate the effect of saline water on the growth and chemical composition of pistachio seedlings, a glasshouse experiment was conducted on five cultivars of pistachio namely, Hajabdolahi, Hajagha-Ali, Jalilaghaii, Parandi, and Lorgi. The experimental design was complete randomized block with three replications in the form of factorial experiment. Treatments included five pistachio cultivars and four levels of salinity (0.5, 5, 10, 15 dS/m). Seedlings were harvested after six months and growth and chemical parameters were measured for roots and shoots (stem and leaves). Increase in irrigation water salinity resulted in increasing Na concentration, shoot length, and K/Na ratio. Results also showed that in comparison to the other cultivars, Parandi could produce more biomass yield under higher level of salinity. Due to high K/Na ratio, Parandi cultivar could be considered as a salt tolerant rootstock under saline conditions.
N A; A R
Abstract
In order to investigate the effect of salinity on morphological, physiological and biochemical characteristics of Lisianthus, a pot experiment was conducted hydroponically in sand. Two Lisianthus varieties (‘Champagne’ and ‘Pure White’) and four NaCl concentrations (0, 20, 40, ...
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In order to investigate the effect of salinity on morphological, physiological and biochemical characteristics of Lisianthus, a pot experiment was conducted hydroponically in sand. Two Lisianthus varieties (‘Champagne’ and ‘Pure White’) and four NaCl concentrations (0, 20, 40, 60 mM) were combined factorially based on a complete randomized design with four replications. The result showed that as salinity increased plant height and fresh and dry weights decreased. Also, chlorophyll a content, photosynthesis rate, and relative water content of plants treated with 60 mM NaCl were, respectively, 31%, 62%, and 20%, lower than the controls. In addition, root length increased with increasing salinity, so that in plants treated with 60 mM NaCl root length was 43% larger than the controls. Further, electrolyte leakage and Malondialdehyde (MDA) content increased with increasing salinity. Results revealed that dry weight, plant height, and photosynthesis rate in ‘Pure White’ were, respectively, 47%, 27%, and 31% higher than in ‘Champagne’. Moreover, under salinity stress, ‘Pure White’ could maintain better morphological and physiological characteristics, i.e. plant height, dry weight, relative water content and cell wall stability compared with ‘Champagne’.
sh z; d h
Abstract
Development projects, along with their positive impacts, have some direct and indirect impacts on natural and social environment that are potentially negative. There may be some undesired consequences if provisions are not foreseen for mitigating the negative impacts and reinforcing the positive ones. ...
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Development projects, along with their positive impacts, have some direct and indirect impacts on natural and social environment that are potentially negative. There may be some undesired consequences if provisions are not foreseen for mitigating the negative impacts and reinforcing the positive ones. Environmental, social, and economic impacts assessment of irrigation and drainage network projects in Korbal plain based on its beneficiaries’ view point was the main objective of this study. Research method was descriptive; non-experimental toward variables controlling; applied toward its object and the data was collected by survey technique. The statistical population of this study included all of the beneficiaries who were farming the modern irrigation and drainage network in Korbal plain, in Fars province. Totally, 280 beneficiaries were selected as sample groups. A questionnaire was used for data collection and its validity was approved by a panel of specialists and its reliability was examined by conducting a pilot study. Cronbach’s alpha coefficient was about 0.79. Findings revealed that most of the beneficiaries believed that the project had relatively desirable environmental, social, and economic impacts. Among four groups of personal, economic, social, and situational determinants, two groups of personal and social determinants had more effect on beneficiaries’ impact assessment. Besides, regression analysis revealed that four groups of attitudinal variables had the highest effect on beneficiaries’ assessment toward the three types of impacts. Some recommendations are presented at the end of the article in order to improve implementation and benefits of such projects.
Elham Saberi; fateme rezaei; a kh
Abstract
Detailed estimation of evapotranspiration is required for water balance studies, water utilities, design and management of irrigation conveyance systems and water resources management, and other purposes. In this study, crop coefficients and water requirements of Ajwain, which is one of the most important ...
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Detailed estimation of evapotranspiration is required for water balance studies, water utilities, design and management of irrigation conveyance systems and water resources management, and other purposes. In this study, crop coefficients and water requirements of Ajwain, which is one of the most important medicinal herbs, were determined during a growing season in College of Agriculture, University of Birjand, by using lysimeters. For this purpose, three weighing lysimeters were used and water requirement of Ajwain was calculated by water balance method. To calculate the reference evapotranspiration, common grass sown in green spaces was used with a height of 12 cm as the reference plant. Finally, at the end of the growing season, values of Ajwain crop coefficients during different growth stages including early stage, crop development, midseason, and late season were obtained as, respectively, 0.78, 1.06, 1.13 and 0.96. Also, the total evapotranspiration of the plant in lysimeter was 492 mm.
masoomeh amerian; alireza Zebarjadi; javaneh alsadat mehrabi
Abstract
Drought is one of the major constraints on agricultural productivity worldwide. Selenium plays an important role in plants tolerance to environmental stresses by increasing the levels of antioxidant enzymes and compounds. In order to investigate the effect of selenium on some growth and physiological ...
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Drought is one of the major constraints on agricultural productivity worldwide. Selenium plays an important role in plants tolerance to environmental stresses by increasing the levels of antioxidant enzymes and compounds. In order to investigate the effect of selenium on some growth and physiological characteristics of the Dragons head (Lallemantia iberica), a factorial experiment was conducted in a completely randomized design with three replications in greenhouse conditions. Treatments included different levels of drought stress (100%, 75%, 50% and 25% field capacity) and different concentrations of selenium (0, 5 and 10 mg.L-1 sodium selenate). Foliar application of sodium selenate was performed in two stages. According to the results, drought stress had a negative effect on fresh and dry weight leaf and yield. But, under drought stress conditions, foliar selenium caused a significant increase in plant height (32.2 cm), proline (0.92 mg/g DW), and total phenol (0.82 mg/g DW) content. Increase in selenium concentration increased Dragons head physiological properties: relative leaf water content (65.10 %), total soluble sugar (2.55 mg/g DW), soluble protein (0.289 mg/g DW), and antioxidant activity (0.21 %). Concentration of 10 mg.L-1 sodium selenate had a positive effect on plant fresh weight and biological yield of Dragons head, which was probably associated with the antioxidant role of selenium. Under drought stress, selenium increased the amount of proline and total phenol, which increased these adaptation osmolytes and had an important role in the drought tolerance of Dragons head.