Research Paper
Karim Noori; Heshmat Omidi; Hasanali Naghdibadi; Hossin Torabi
Abstract
Water and soil salinity limit crop production in arid and semi arid areas. Evaluation of salt tolerance of medicinal plants is important, particularly, for their cultivation in saline areas. To evaluate the effect of salinity of water and soil on chamomile plants yield, a greenhouse experiment was conducted ...
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Water and soil salinity limit crop production in arid and semi arid areas. Evaluation of salt tolerance of medicinal plants is important, particularly, for their cultivation in saline areas. To evaluate the effect of salinity of water and soil on chamomile plants yield, a greenhouse experiment was conducted using completely randomized design with five levels of water salinity including control, 3.5, 6.5, 9.5 and 12.5 dS.m-1 in three replications. The study was conducted in the Research Greenhouse of Biology Department of Shahed University, Tehran. In this study, parameters including morphological attributes, proline and protein content, plant content of Na, K, Ca, and Cl, percentage of essential oil and Chamazulene were evaluated. The results showed that, with increasing salinity, growth parameters of chamomile plants decreased significantly. A change in the amount of secondary metabolites was significant as compared with the control, in which salinity decreased essential oil (35.23%) and increased chamazulene percent (26.31).Compared with the control plant, amount of NA+ in stem (54.34%) and root (60%) and also Cl- in stem (68.42%) and root (76.19%), of chamomile plants increased with increasing salinity levels, thereby decreasing the absorption of Ka and Ca elements by chamomile. The results showed that cultivation of medicinal plants like chamomile, which are relatively tolerant to salinity, helps in reclamation and improvement of saline soils and can lead to high crop yield with a relatively good quality.
Research Paper
Toktam Fakoori; Hojat Emami; Bizhan Ghahremani
Abstract
Water infiltration into soil plays an important role in water cycle, but its measurement is expensive, time consuming, and difficult, and it has spatial and temporal variations. Therefore, estimating the infiltration rate using emprical and physical models and/or indirect estimation of infiltration with ...
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Water infiltration into soil plays an important role in water cycle, but its measurement is expensive, time consuming, and difficult, and it has spatial and temporal variations. Therefore, estimating the infiltration rate using emprical and physical models and/or indirect estimation of infiltration with more convenient soil properties is essential. The aim of this research was to estimate the cummulative infiltration rate of water into soil by using particle size distribution (PSD) data and water retention shape parameter. Cummulative infiltration rate was measured in agricultural, horticultural, and pasture land uses in Neyshabour town of Khorasan Razavi province (Iran). Infiltration measurement was performed by single cylinder (Beerkan's method) at 5 points with 3 replications for each land use. The measured results were compared to those fitted with Philip two terms, Lassabatere et al., and Minasny and McBratney equations. It was revealed that using PSD data for estimating water retention shape parameter and, then, assessing the cumulative infiltration rate in the three land-uses significantly increased determination coefficient (R2) in relation to Philip model. The root mean square error (RMSE) obtained from fitting Lassabatere et al. model decreased significantly in comparison to Philip model in pasture and horticultural land uses. In reverse, use of Minasny and McBratney method decreased R2 in relation to Philip model in the three land uses. In agricultural land use, the highest and lowest RMSE were obtained from fitting data on Philip and Minasny and McBratney models, respectively. Mean error (ME) obtained from Philip model was positive in the three land uses, reflecting the overestimation of this model. Also, except in the pasture, in other land uses, the ME values obtained from fitting the studied models for estimating cumulative infiltration rate were positive. According to the results of this research, use of PSD for estimating water retention shape parameter and, then, assessing cumulative infiltration rate by Lassabatere et al. model is recommended.
Shahram Karimi; Rasoul Asadi
Abstract
Using mathematical models for irrigation management have great impacts on increasing irrigation efficiency and crop yield. Therefore, in order to evaluate the SWAP model performance in estimating corn production under water stress, a field experiment was conducted on grain maize in Urzuieh plain of Kerman ...
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Using mathematical models for irrigation management have great impacts on increasing irrigation efficiency and crop yield. Therefore, in order to evaluate the SWAP model performance in estimating corn production under water stress, a field experiment was conducted on grain maize in Urzuieh plain of Kerman province in Iran, during 2009 and 2010. The experimental design was split plot in randomized block with four replications. Water was used at four levels (100%, 80%, 60% of maize water requirement and a control treatment consisting of the amount of water used by the local farmers) as the main factor and the three varieties of maize (single cross 704, 700,404) were as the sub factor. The results showed perfect compliance of yield and leaf area index (LAI) between values simulated by the model and measured values in the field. In the two study years, R2 between the measured yield and values simulated by the model were 0.99 and 0.998, respectively, while the corresponding R2 for LAI were 0.86 and 0.87. Considering the salinity of irrigation water (EC = 4 dS/m), the volume of water for maximum relative yield (77%) was found to be 11000 cubic meter per hectare. Moreover, evaluation of water salinity levels, indicated 7 present yield reduction per 2 dS/m increase in water salinity. Therefore, calibrated SWAP model can be used as an instrumental tool for calculating all parameters of plant at field scale, with time and cost saving.
Research Paper
Alireza Alipour; Mohammadhasan Vakilpour; Rasoul Afshartabar; Mojtaba Nikzad
Abstract
Occurrence of frequent droughts along with the current global energy crisis calls for attention to efficient use of water resources and improvement of water productivity level. Also, when other production inputs are used, the relationship and interaction between those inputs and water play important ...
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Occurrence of frequent droughts along with the current global energy crisis calls for attention to efficient use of water resources and improvement of water productivity level. Also, when other production inputs are used, the relationship and interaction between those inputs and water play important roles and should be considered in research. In this study, water use efficiency is investigated from an economic perspective. Hence, in order to assess wheat technical efficiency and water use efficiency, data envelopment analysis was used. To this end, information of 150 wheat beneficiaries in Zarghan, Fars province, was used in 2010-2011 crop season. The results showed that the mean water use efficiency in the region was very low and about 32 percent. Also, according to the results of T-test used to compare the water use efficiency among input-efficient and input-inefficient group, it was revealed that the mean water use efficiency in efficient producers was significantly more than inefficient farmers. Finally, policy recommendations for increasing water use efficiency in producing wheat in the region and improving technical efficiency is presented.
Research Paper
Zakaria Ghaderi; Ardeshir Hezarkhani
Abstract
Hydrochemical quality of groundwater in Chahardoli Basin in Qorveh, located in the west of Iran, was investigated in this study. Sixty six groundwater samples were taken in an area of 340 square kilometers and analyzed for the concentration of major ions, electrical conductivity (EC) and pH. Spatial ...
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Hydrochemical quality of groundwater in Chahardoli Basin in Qorveh, located in the west of Iran, was investigated in this study. Sixty six groundwater samples were taken in an area of 340 square kilometers and analyzed for the concentration of major ions, electrical conductivity (EC) and pH. Spatial distribution maps of cation and anion concentrations and electrical conductivity (EC) of water has shown that the concentrations of ions in the central parts of the basin are higher than in other parts. Due to high concentrations of ions, all of the water samples were not categorized in suitable ranges for drinking use. Groundwater is used for agriculture in this region, therefore, various methods were used for assessing the suitability of groundwater for irrigation. USSL diagram showed that 59 wells had acceptable quality for agricultural purposes. The dominant type of groundwater in the area was that is a common type of fresh water in Iran
Research Paper
Maryam Roostai; Teymour Sohrabi; Alireza Mesah; Mohammadsadegh Ahadi
Abstract
A variety of factors contributing to food insecurity should be evaluated precisely. Among these factors, climate change has the major influence. This study evaluates risk analysis of maize biomass under climate change in the period of 2010-2039, in a maize field in Pakdasht (east of Tehran, Iran) using ...
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A variety of factors contributing to food insecurity should be evaluated precisely. Among these factors, climate change has the major influence. This study evaluates risk analysis of maize biomass under climate change in the period of 2010-2039, in a maize field in Pakdasht (east of Tehran, Iran) using AOGCM uncertainties. Climate Change scenarios were derived from 9 climate experiments (9 AOGCMs under A2 emission scenario) for two time periods (1971-2000 and 2010-2039). Beta probability density function (pdf) was fitted to these scenarios and 2000 samples of temperature and rainfall of climate change scenarios were produced. Also, their cumulative distribution functions (cdf) were depicted and changes of temperature and rainfall at 25%, 50%, and 75% risk levels were extracted. LARS-WG model was used for statistical downscaling of data and AquaCrop model was employed in simulation of maize biomass for future period (2010-2039).Descending trend was detected from biomass simulation in future period. At 50 % risk level, decreasing biomass was 1.21 ton per hectare in full irrigation treatment and 1.42 ton per hectare in deficit irrigation treatment. Risk analysis results showed that difference between 25% and 75% risk’s biomass amount in full and deficit irrigation were 0.7 and 0.5 ton per hectare, respectively.
Research Paper
Mehri Safari
Abstract
Increase in the world population has increased demand for water. Sewage has been used in different countries in agriculture and landscape irrigation. Its high nutrient load increases crop yields and reduces the need for costly fertilizer inputs. But, concentration of heavy metals in agricultural products ...
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Increase in the world population has increased demand for water. Sewage has been used in different countries in agriculture and landscape irrigation. Its high nutrient load increases crop yields and reduces the need for costly fertilizer inputs. But, concentration of heavy metals in agricultural products irrigated by sewage is a cause of serious concern due to potential health problems of contaminated products. In this research, a pistachio orchard in the lands of Shahid Bahonar University in Kerman, Iran, was irrigated with treated sewage and different parameters and data were collected. Results showed that heavy metals such as Cd, Pb, Cu, and Zn were absorbed by pistachio roots and transported to other organs, tissues, and fruits. The amount of Pb, Cu, Cd, and Zn in pistachio fruits irrigated with sewage was higher than ATSDR standards, which means that this practice may cause health problems for consumers and could put the environment at risk. One possible solution for sewage usage can be mixing it with irrigation water in different ratios, as was done in this research.
Research Paper
Zeynab Yeganeh; Javad Behmanesh; Hossin Rezaee
Abstract
In all trickle irrigation systems, creating pressure is necessary to provide the crop water requirement. Pressure loss in the system affects the final cost, application efficiency, distribution uniformity, and work condition of the system. This research was conducted to evaluate the trickle irrigation ...
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In all trickle irrigation systems, creating pressure is necessary to provide the crop water requirement. Pressure loss in the system affects the final cost, application efficiency, distribution uniformity, and work condition of the system. This research was conducted to evaluate the trickle irrigation systems in seven orchards in Marand, northwest of Iran. Since changing surface irrigation systems to pressurized irrigation systems is rapidly expanding in the studied region, the investigation of changed systems efficiency has an important role in water and soil manager's decisions working at regional agricultural office i.e. Jahad-e-Keshavarzi office in Marand. In the present research, for systems evaluation, Meriam-Keller and random methods were selected. The random method was selected to decrease the time and cost of the evaluation. In order to evaluate these systems, the quantitative values of water distribution uniformity, application efficiency of low quarter, actual application of low quarter, and factors affecting these parameters were calculated. The results showed that, for trickle irrigation systems, the average distribution uniformity and potential and actual application of low quarter were 95%, 80%, and 92%, respectively. Considering the obtained results, it was clear that the high efficiency and water distribution uniformity, low manufacturing variation coefficient of emitters, low discharge variation in compensating emitters, and no clogging of outlets were due to correct functioning of the system filtration, proper design and implementation, and high quality of the equipment. According to the results, variations of elevation affect the discharge and pressure variation. The results showed that hydraulic design of the systems was acceptable. The results were similar in the selected methods. The results of water quality analyses showed the possibility of calcium carbonate and sulfate deposition in the systems with time. Values of pH, hardness, and dissolved salts were not beyond standard limits and had no hazardous effects. The concentrations of Fe and Mg were less than that causing clogging.
Research Paper
Hormoz Asadi; Alireza Tavakoli; Shahram Ashrafi
Abstract
Limited irrigation in rainfed cultivation must be investigated from economic aspects to determine the best agronomic management practices. The purposes of this study were to determine cost and benefits of rainfed wheat production under traditional and advanced managements (AM), determine the price of ...
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Limited irrigation in rainfed cultivation must be investigated from economic aspects to determine the best agronomic management practices. The purposes of this study were to determine cost and benefits of rainfed wheat production under traditional and advanced managements (AM), determine the price of irrigation water with proper discount rate, and economics of substitution of treatments under different managements. Experimental treatments included two levels of agronomic managements (traditional and advanced management) with different levels of supplemental irrigation (rainfed, single irrigation (SI) at planting time, and SI at spring time). Field experiments were carried out in some typical farmers’ fields and the requiered data was collected. In this study, in order to select the best irrigation treatments, agronomic managements, and the price of irrigation water at Merek Catchment, in Kermanshah province, in the upper Karkheh river basin, Partial Budgeting (PB) technique and Engineering Economy Methods (uniform series formulas)were used during 2005-07. Results showed that the mean of production cost under traditional and advanced management was estimated at 1107.5 and 1567.5 thousand Rials per hectare, respectively. Compared to other treatments, AM-SI spring treatment was more economical. The mean of the net benefit of this treatment was estimated at 5664 thosands Rials/ha, which was more than the other treatments. Present value of uniform annual cost for capital costs was estimated at 24723.3 thousand Rials with discount rate of 7%. Based on the current costs and volume of water used i.e. 199584 m3, the price of irrigation water was estimated at 123.9 Rials/m3.
Research Paper
Samaneh Gholami; Ebrahim Amiri; Ali Abedzad gohari
Abstract
In order to study the effects of irrigation interval and nitrogen rates on yield and water use efficiency (WUE) of maize (Zea mays L) using KSC704 maize hybrid, an experiment was conducted in agricultural research farm of Lahidjan, Guilan, north of Iran, using split plot in randomized complete block ...
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In order to study the effects of irrigation interval and nitrogen rates on yield and water use efficiency (WUE) of maize (Zea mays L) using KSC704 maize hybrid, an experiment was conducted in agricultural research farm of Lahidjan, Guilan, north of Iran, using split plot in randomized complete block design with three replications, during 2010. The main plots were three irrigation regimes including rainfed and irrigation intervals of 6 and 12 days. The sub-plots were five nitrogen rates consisting of 0, 60, 120, 180, and 240 kg N/ha. The results indicated that the effects of irrigation, nitrogen, and their interaction on grain yield, biomass, biomass WUE, and seed yield WUE were significant at α=1%. The highest biomass WUE and grain yield WUE were 6.82 and 2.92 kg/m3, obtained from application of, respectively, 180 and 240 kg N/ha-1 under rainfed conditions. Higher rates of nitrogen and application of irrigation led to increase in seed yield and biomass, but, differences between irrigation intervals of 6 and 12 days and N180 and N240 fertilizers treatments were not significant. The lowest grain yield and biomass were observed in rainfed condition with no N application. Stomata conductivities were significantly higher in the 6-day irrigation interval. The lowest relative water content belonged to rainfed treatment.
Research Paper
Hossin Babazadeh; Mehdi Sarai tabrizi
Abstract
Uneven temporal and spatial distribution of precipitation and lack of management in the supply and demand of water resources in the country, particularly in very dry areas such as Hormozgan province, has caused agriculture sector to face serious problems. In this regard, virtual water trade in the country ...
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Uneven temporal and spatial distribution of precipitation and lack of management in the supply and demand of water resources in the country, particularly in very dry areas such as Hormozgan province, has caused agriculture sector to face serious problems. In this regard, virtual water trade in the country can solve the main parts of the problems in water distribution at a lower cost. The results of this research showed that the total annual import and export of virtual water in Hormozgan province were, respectively, 1284.3 and 1131.1 million cubic meters (MCM). The share of the field crops, horticultural crops, and livestock sector from the imported virtual water is 61.44%, 9.97%, and 28.59%, while their contribution to the exported virtual water is 35.32%, 59.18% and 5.5%, respectively. Equivalent volume of virtual water trade balance in this province was found to be 142.5 MCM. Also, indexes of water stress, water use intensity, water dependency and water self-sufficiency to virtual water import of Hormozgan province were 63%, 58%, 9.6%, and 90.4%, respectively. One of the most important causes of virtual water export in Hormozgan province is production of products like dates, vegetables, and summer crops that use a lot of water. The important source of the virtual water imports into the province is the import of rice and wheat. Also, the results of this study show that Hormozgan province has a relatively low potential in using green water, such that only about 7.8% of field and horticultural crops are produced by green water. Therefore, it is recommended that crop pattern of Hormozgan province be shifted toward more use of green water (like in cereals and fruits) and planting summer crops such as corn and potato, which use a lot of water, be avoided.
Research Paper
Azam Borzooi; Mohammad Kafi; Mirahmad Mousavi; Ali Khorasani
Abstract
To determine the effect of different levels of nitrogen and salinity on yield and nitrogen use efficiency of two wheat cultivars, a field experiment was conducted at Salinity Research Station of Agricultural College, Ferdowsi University of Mashhad, in 2007-08 and 2008-09 growing seasons. A split plot ...
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To determine the effect of different levels of nitrogen and salinity on yield and nitrogen use efficiency of two wheat cultivars, a field experiment was conducted at Salinity Research Station of Agricultural College, Ferdowsi University of Mashhad, in 2007-08 and 2008-09 growing seasons. A split plot layout within a randomized complete block design with three replications was used. Three levels of salt stress (1.3, 5, and10 dS/m) were assigned to the main plots and a combination of three levels of ammonium sulfate (50, 100, 150 kg N/ha) and 2 wheat genotypes, namely, Bam (resistant) and Toos (susceptible to salt stress) were allocated to subplots. In the second year, micro plots (1 by 1.5 m) were established within the main experiment to monitor uptake of 15 N-labeled fertilizers. Results indicated that the percentage of N derived from labeled fertilizer was significantly (P≤ 0.05) higher in 150 kg ha-1 at salinity level of 10 dS/m than the other N levels. The highest and lowest FNU were observed in 50 and 150 kg N.ha-1, respectively. Chlorophyll content, grain yield, and potassium concentration in the aboveground plant decreased significantly with increasing salinity treatment. There were also significant differences in grain yield, chlorophyll content, and potassium concentration between the various rates of N fertilizer. The Na concentration decreased significantly with the increase in nitrogen application up to 150 kg N.ha-1 and also increased significantly with the increase in salinity treatments up to 10 dS/m. The results showed that an increase in fertilizer-nitrogen absorption by plant had occurred when application of nitrogen fertilizer exceeded wheat requirements. It seems that this condition increases the tolerance against the ill effects of salt stress in wheat.