Irrigation
M. Goodarzi; F. Abbasi; A. Hedayatipour
Abstract
IntroductionThe lack of water resources and increase in water demand are among the effective factors in the imbalance of the water resources in each region, and it is necessary to manage the proper use of available water resources in all activities. Water in the agricultural sector is one of the main ...
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IntroductionThe lack of water resources and increase in water demand are among the effective factors in the imbalance of the water resources in each region, and it is necessary to manage the proper use of available water resources in all activities. Water in the agricultural sector is one of the main factors of production, which should be conveyed by irrigation systems to the field level and made available for the plant roots. The necessity of macro-planning in water management and consumption imposes a comprehensive study of the amount of water consumed in the agricultural sector. Hence, this study was conducted with the objective of directly measuring and field-assessing the applied water, water productivity, and water footprint associated with the primary crops cultivated in Markazi Province, all managed by local farmers.MethodologyFor this purpose, 141 farms were selected in the major production areas of the main agricultural and horticultural crops of Markazi province with the coordination of the Agricultural Jihad centers. Then, the volume of water applied was measured without interfering in the irrigation scheduling of the users. To do so, first, the flow rate of the water source (canal, well, aqueduct or spring) was measured with a suitable device (flume and meter) in each of the selected farms. Then, by carefully monitoring the irrigation schedule of the farm, including the time of each irrigation, the number of irrigation throughout the year, as well as measuring the area under crop cultivation, the amount of water used by the crop was measured for each of the selected farms during the season. Also, based on the measured data, the amounts of blue, green and gray water footprints were determined for each of the examined crops. For this purpose, the blue, green and gray water footprints of different crops were calculated using the framework provided by Hoekstra and Chapagain (2008), and Hoekstra et al., (2011).Results and DiscussionThe irrigation intervals in the studied fields varied between 3 and 15 days with an average of 8 days and the average irrigation depth varied between 26.2 and 99 mm with an average of 67.8 mm in different crops. The results showed that the average volume of applied water for the studied crops in Markazi province was 10782 cubic meters per hectare. Also, the minimum and maximum amount of applied water for the evaluated crops was as follows: barley 3783 and 7232, alfalfa 10382 and 19797, beans 8280 and 17840, watermelon 5333 and 7174, walnuts 4420 and 29600, almonds 3850 and 13932, peaches 6872 and 17727, cherries 7050 and 14645, pomegranates 7156 and 20790, and grapes 5937 and 18168 cubic meters per hectare. Furthermore, the average value of irrigation water efficiency index and water footprint was as follows: barley 0.46 and 1642, alfalfa 0.92 and 700, bean 2924 and 0.24, watermelon 9.37 and 117, walnut 0.1 and 6706, almonds 0.16 and 6857, peach 2.48 and 242, cherries 0.73 and 875, pomegranates 1.33 and 636, and grapes 11.2 and 322. Based on the obtained results, the average total water footprint index was equal to 2102 cubic meters per ton. On average, the almond with a water footprint of 6857 cubic meters per ton had the highest share in allocating the water footprint in the crop production of the province. Whereas, the lowest water footprint related to the watermelon with a water footprint of 117 cubic meters per ton. he average values of the irrigation application efficiency index, irrigation water productivity, and water footprint for the examined farms were 72.5%, 1.79 kg/m3, and 2,102 m3/ton, respectively. In summary, the results indicate that the combined volume of irrigation water and beneficial rainfall in the irrigated fields within Markazi Province surpasses the actual water demand of the crops. This underscores the substantial impact of irrigation management on water utilization in the region.ConclusionOn average, the total volume of irrigation water and effective rainfall in irrigated fields and gardens in Markazi Province is more than the actual water requirement of the plant. In general, the results showed that irrigation management has a great impact on the amount of water use in the region. Based on the obtained results, considering that most of the farms and gardens receive water in an intermittent manner, in principle, no special attention is paid to the need for water and even effective rainfall, and the amount of water availability has the greatest impact on water consumption. Therefore, in order to reduce water consumption and improve water efficiency, it is suggested to manage the delivery of water to farmers during the season and according to their crop water needs. Also, the results of the water footprint can be used to improve water resource policies at the province level, land use studies, cropping pattern modification, and environmental sector policies.
Irrigation
H. Ojaghlou; F. Ojaghlou; Mohammad Mahdi Jafari; Farhad Misaghi; Bijan Nazari; Esmaeil Karami Dehkordi
Abstract
Introduction
Over the last years, long-term average rainfall has experienced a meaningful decrease (from 250 to 206 mm per year) leading to continuous drought in Iran. In addition, population growth and increasing demand for food put more pressure on the limited available water resources. Thus, the ...
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Introduction
Over the last years, long-term average rainfall has experienced a meaningful decrease (from 250 to 206 mm per year) leading to continuous drought in Iran. In addition, population growth and increasing demand for food put more pressure on the limited available water resources. Thus, the quantitative and qualitative improvement of agricultural products become a necessity. There is 640,000 hectares of alfalfa cultivated land, standing for 5.4% of the total cultivated area. One of the most basic obstacles in these farms is the unsuitable model of water consumption management. Previous studies were conducted with the aim of evaluating the mutual effects of different treatments in controlled plots. Nonetheless, there is a need for large-scale investigations to monitor and improve water productivity in agricultural systems. In this research, the focus was on irrigation management and optimizing irrigation timing as a potential solution to enhance water productivity, considering the fixed irrigation cycles and traditional use of available water resources. The study began by assessing the current water productivity in 11 alfalfa farms located across four regions in Zanjan province, ensuring a suitable spatial distribution. Subsequently, the impact of irrigation management, particularly the adjustment of irrigation timing, was evaluated to determine its effectiveness in improving water productivity in these farms.
Materials and Methods
Eleven alfalfa farms, covering a total area of 28 hectares, were initially selected in the agricultural lands of Zanjan province. The majority of these farms were equipped with sprinkler irrigation systems. From these 11 farms, two specific farms were chosen to implement the proposed methods aimed at improving water productivity. These selected farms served as experimental sites where the irrigation management techniques were applied and evaluated. Improvement solutions were mainly focused on irrigation management. Each farm was divided into two parts; one part with real conditions (farmers' management) and the second one with controlled conditions. In the controlled treatments, irrigation management was implemented through optimization of irrigation time. A nutritional program was also prepared according to the soil quality of the fields and applied in the controlled treatments. In each farm, basic information such as area, physical and chemical properties of soil and water quality were determined. Irrigation information (such as inflow discharge and irrigation schedule) was measured and determined at least three times during the cropping season. Soil moisture were measured before and after irrigation in order to calculate the water application efficiency. The amount of harvested product and production costs were obtained at the end of the cropping season through measurements and interviews with farmers. In this research, the indicators including the volume of irrigation water, the water use efficiency, and the physical and economic efficiency of water have been calculated to analyze the water productivity.
Results and Discussion
The volume of irrigation water in alfalfa farms was measured as 14250 m3/ha on average (with the lowest and highest consumption values of 9849 and 20576 m3/ha, respectively). The average of irrigation water in farms with surface irrigation systems equals to 17,806 and in farms equipped with sprinkle irrigation systems is about 13,460 m3/ha. While the net water requirement of alfalfa in study area was 7160 to 7290 m3/ha. The minimum and maximum values of water application efficiency were 38.3 and 82%, respectively, with average of 64%. The average of application efficiency in surface and sprinkle irrigation systems were obtained 50 and 67%, respectively. The measured alfalfa yield ranged from a minimum of 6.5 ton/ha to a maximum of 14.1 ton/ha, with an average yield of 10.4 ton/ha. After implementing the revised irrigation program in the controlled plots, the harvested water decreased by an average of 49.5%. It was observed that the irrigation schedule in most farms followed a traditional and estimated pattern, with the depth of irrigation water in the middle of the growing season exceeding the net irrigation requirement. The water use efficiency (WUE) values varied between 0.42 and 1.28 kg/m3, with a minimum value of 0.42 kg/m3 and a maximum value of 1.28 kg/m3. The average WUE was calculated as 0.79 kg/m3. Analyzing the correlation between water consumption and the water use efficiency index revealed a decreasing trend. As the volume of irrigation water increased, the water use efficiency index experienced a decline. Specifically, an increase of 1000 m3 in irrigation water resulted in a decrease of 0.04 kg/m3 in the water use efficiency index. The implementation of the corrected irrigation program and appropriate to the water demand led to an increase of the mentioned index by 72%.
Conclusion
The lack of proper irrigation programs that consider climatic conditions and the actual needs of the alfalfa plant was identified as a key factor contributing to high water consumption in the farms. Additionally, the inefficient selection and design of the irrigation system led to lower irrigation efficiency than expected. Despite the majority of farms being equipped with sprinkle irrigation systems, the harvested water did not decrease significantly due to inadequate water management practices. These factors ultimately resulted in a decline in both physical and economic productivity indicators in the alfalfa farms. However, the results of the study highlighted that implementing corrected irrigation management, particularly through modifications to the irrigation timing, can lead to a significant decrease in volume of irrigation water and an improvement in both physical and economic productivity.
Irrigation
A. Asadi; H.R. Khazaie; J. Nabati
Abstract
IntroductionDue to climate change, one of the limiting factors of crop production is environmental stress which, by disrupting the natural metabolism of the plant, limit plant growth and finally reduce crop production. Drought stress causes the greatest reduction in crop productivity compared to ...
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IntroductionDue to climate change, one of the limiting factors of crop production is environmental stress which, by disrupting the natural metabolism of the plant, limit plant growth and finally reduce crop production. Drought stress causes the greatest reduction in crop productivity compared to other environmental stresses. Therefore, the use of methods to reduce water consumption in agriculture is more important due to the lack of freshwater resources. Increasing water use efficiency and maintaining plant yield by reducing water consumption has a particular importance for crop production and should be paid special attention. Drought stress reduces photosynthesis, stomatal conductance, biomass, growth and consequently plant yield. The effects of drought stress on the yield of plants such as potatoes (Solanum tuberosum L.), wheat (Triticum aestivum L.), rice (Oryza sativa L.) etc., which play an important role in the nutrition and food of the world, has a great importance. Achieving the desired soil moisture range is one of the most important approaches to increase water use efficiency and not significantly reduce yield. For this goal, a factorial experiment was conducted in a completely randomized design with five replications in the research greenhouse of Ferdowsi University of Mashhad.Materials and MethodsFactors studied in this experiment included three levels of irrigation 1- full irrigation (100% of field capacity), 2- medium drought stress (70% of field capacity), 3- partial root-zone drying (70% of field capacity), time of induction of water stress (two weeks after planting and 50% at flowering time) and two levels of phosphate (CaH4[Po4]2 H2O) fertilizer (based on soil analysis (25 mg.kg-1) and adding 25% more than recommended (31 mg.kg-1)) at the beginning of the period phosphate was mixed with soil inside the pot in greenhouse condition. Fontane potato cultivar was used in this study. In irrigation treatments, one part of the pots was stressed two weeks after planting and the second part of the pots were fully irrigated until the beginning of flowering and irrigation treatments were applied at 50% flowering stage. From the prepared samples, membrane stability index, osmotic potential, and relative water content were measured in the laboratory and at the end of experiment, plant height, tuber weight, biomass and plant water use efficiency were measured. Minitab 18 software was used to analyze the data.Results and DiscussionThe results showed that with increasing phosphate fertilizer from 25 mg.kg-1 to 31 mg.kg-1, plant biomass increased significantly and in all treatments biomass increased between 2 to 28% . Partial root-zone drying treatment showed a 17.4% increase in biomass. In the medium drought stress treatment, the total growth period and phosphorus level of 31 mg.kg-1, the lowest water use efficiency was observed, and there was no significant difference in the medium drought stress treatment of the total growth period and the phosphorus level of 25 mg.kg-1. Partial root-zone drying treatment of roots from flowering time and 31 mg.kg-1 P, with full irrigation treatment 25 mg.kg-1 P have the same water use efficiency, but the performance of this treatment compared to full irrigation treatment was reduced by 28%. Water use efficiency in partial root-zone drying (intermittent irrigation) has increased compared to traditional irrigation, which indicates a more optimum use of water in the medium drought stress method. Full irrigation treatment had the highest tuber weight per plant and partial root-zone drying during the growing season treatment had the lowest tuber weight per plant (65%) compared to full irrigation. The partial root-zone drying treatment after flowering, ranked second after full irrigation treatment, for tuber weight per plant and more tuber weight per plant compared to other drought treatments. Using 31 mg.kg-1 phosphate, tuber weight per plant in full irrigation treatment reached 332 g.plant-1 which increased by 13% and was significantly different from all treatments. With increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, in the partial root-zone drying treatment from flowering time, tuber weight per plant increased by 28% to 207 g.plant-1. Tuber weight per plant in other drought treatments decreased with increasing phosphate level from 25 mg.kg-1 to 31 mg.kg-1, although this decrease was not statistically significant. ConclusionCompared to deficit irrigated methods, partial root-zone drying from the beginning of growth and full irrigation has the ability to use available nitrogen at the end of the growing season and has more greenery than other drought treatments. This effect probably explains the filling of the gland tubers at the end of the growing season and thus the keeping of yieldyield production. The best methods for saving water consumption and maintaining the yield, the partial root-zone drying methods is better than the medium drought stress method.
Irrigation
M.R. Emdad; A. Tafteh; N.A. Ebrahimipak
Abstract
Introduction
Quinoa (Chenopodium quinoa) is native plant in Bolivia, Chile and Peru, which is widely adapted to different climatic conditions and can grow in all soils. This plant has shown adequate adaptation to arid and semi-arid areas conditions and is planted from areas with low elevation ...
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Introduction
Quinoa (Chenopodium quinoa) is native plant in Bolivia, Chile and Peru, which is widely adapted to different climatic conditions and can grow in all soils. This plant has shown adequate adaptation to arid and semi-arid areas conditions and is planted from areas with low elevation (sea level) to areas with an altitude of 4000 meters above sea level. Quinoa is often cultivated in areas with limited water resources, and it is rare to find quinoa cultivation under full irrigation conditions. Some studies have shown that quinoa yields slightly better under full irrigation (without water restriction) than quinoa under deficit irrigation. Crop growth models are very important tools in the study of agricultural systems and they can be used to simulate the yield of crop in different conditions. Given that the study of performance limiting factors requires numerous and costly research and experiments in different areas, so finding a way to reduce the number, time and cost of these experiments is worthwhile. Aquacrop model is one of the applied models that are used to simulate yield variations in different water and soil management.
Materials and Methods
This investigation was carried out in two growing seasons of 2019 and 2020 to determine the efficiency of Aquacrop model for simulating Quinoa grain yield and biomass under imposing three stress treatments of 30, 50 and 70% of water consumption in development and mid-growth stages. Plant spacing was 40 cm between rows and 7 cm between plants within rows. Seeds of quinoa (Titicaca cultivar) were cultivated in the first decade of August 2019 and in the third decade of July 2020. The experiment was a randomized complete block design with three replications. Three deficit irrigation treatments including 30, 50 and 70% of available water were considered in two growth stages (development and mid-growth) in 18 experimental plots (3 × 4 m). Soil moisture in rooting depth (about 40 cm) was measured by TDR and after the soil moisture of the treatments reached the desired values, plots were irrigated until the soil moisture reached the field capacity. The results of grain and biomass yield in the first year were used to calibrate the Aquacrop model and the results of the second year were used to validate the model. Root mean square error (RMSE), normalized root mean square error (NRMSE), Willmott index (D), model efficiency (EF) and mean error deviation (MBE) were used to compare the simulated and observed values.
Results and Discussion
The results of the first and second year were used to calibrate and validate the model, respectively. The results of the first year showed that irrigation with 50 and 70% of available water in the development stage reduced quinoa grain yield by 17 and 33%, respectively, compared to the control treatment. The application of these two deficit irrigation treatments in the middle stage reduced the yield by about 12 and 28%, respectively. The results of comparing the statistical indices of grain yield, biomass and water use efficiency showed that the NRMSE for grain, biomass and water use efficiency were 9, 8 and 14% in the first year and 9, 6 and 9% in the second years. Furthermore, the EF for these traits were 0.81, 0.77 and 0.64 in the first year and 0.68, 0.71 and 0.62, in the second year, respectively.
Conclusion
The results of calibration and validation of the model showed the accuracy and efficiency of the Aquacrop model in simulating grain yield, biomass and water use efficiency of quinoa. This model can be used to provide the most appropriate scenario and irrigation management for different levels of deficit irrigation managements.
Irrigation
A. Aliverdi; S. Karami; H. Hamami
Abstract
Introduction: Since rainfall occurs often in the fall and winter, water is an important limiting factor to subsequent growing crops especially those in hot seasons like soybean. Therefore, there is a growing focus on increasing water use efficiency in crops in recent years. Recently, an irrigation technique ...
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Introduction: Since rainfall occurs often in the fall and winter, water is an important limiting factor to subsequent growing crops especially those in hot seasons like soybean. Therefore, there is a growing focus on increasing water use efficiency in crops in recent years. Recently, an irrigation technique so-called magnetized water has been introduced to increase water use efficiency. The researchers have reported that the physical and chemical properties of water including electrical conductivity, volatility, pH, solubility, surface tension, and viscosity can be affected by its passage through the magnetic field. Subsequently, these changes lead to alterations in soil electrical conductivity, soil nutrient mobility, soil water holding capacity, water passage through the soil profile and soil pH. Increased water use efficiency in soybean (11%) and many leguminous crops have been demonstrated through their irrigation with magnetized water. However, those studies have provided no information about the status of bacterial nodulation on legume root in such an irrigation method. Therefore, the main purpose of this study was to investigate the effect of irrigation with magnetized water on five soybean varieties on their symbiosis with specific bacteria (Bradyrhizobium japonicum). Materials and Methods: The experiment was conducted in the open air at the Bu Ali Sina University of Hamedan in 2018. A completely randomized design with two factors (soybean cultivar and irrigation water type) and eight replications was applied. The soybean cultivar had five levels (Amir, Zan, Saba, Kosar, and Hobbit) and irrigation water type had two levels (untreated and magnetically treated water). An equal volume of water (1 liter) was added to each pot every two days. Before adding water to pots for the irrigation with magnetized water, we passed it through a magnetic tube with a 35 cm long, 1-inch radius and a 0.68 T magnetic field intensity. On August 26, the plants of the half of replications were harvested to measure shoot dry weight, root dry weight, number of nodules, nodule dry weight, shoot nitrogen content and root nitrogen content. On September 10, the plants of the other half of replications were harvested to measure individual seed yield and its components (number of pods per plant, number of seeds per pod and 100-seed weight). By dividing the seed yield obtained from each pot to the total volume of water added to each pot during the growing season, water use efficiency can be calculated. Results and Discussion: The soybean seedlings irrigated with magnetized water were green 1 to 2 days earlier than those irrigated with untreated water. The number of seeds per pod was not affected by soybean cultivar, irrigation water type, and their interaction. In other traits, the simple effects of soybean cultivar and irrigation water type and their interaction were significant at the 5% level of probability. The cultivars of Amir and Saba irrigated with magnetized water led to a higher shoot dry weight to root ratio, indicating the allocation of more resources to the shoot than to the root. The number of nodules formed on the root of all soybean cultivars (Amir (33.7%), Zan (55.3%), Saba (40.1%), Kosar (62.7%) and Hobbit (51.6%)) increased when they were irrigated with magnetized water. However, only in Zan (0.70%) and Kosar (45.1%), irrigation with magnetized water significantly increased the dry weight of nodules. The individual seed yield in all soybean cultivars (Amir (34.8%), Zan (35.1%), Saba (43.4%), Kosar (26.8%) and Hobbit (21.3%)) was significantly increased by irrigation with magnetized water, indicating an improved water use efficiency in soybean irrigated with magnetized water. Based on previous research, the most suitable soil pH range for bacterial growth and activity was found to be between 6.5 and 7.0. On the other hand, other researchers have shown that irrigation with magnetized water reduces the soil pH by approximately 0.5 units. Hence, in our experiment, irrigation with magnetized water probably caused the initial soil pH which was 7.6 to be closer to the optimal range for bacterial activity. Also, according to previous study, bacterial activity is also dependent on soil dry conditions. On the other hand, other researchers have shown that irrigation with magnetized water increases soil water storage capacity due to reduced water vaporization. Therefore, in our experiment, irrigation with magnetized water probably provided good moisture conditions for bacterial activity. Conclusion: The results showed that the irrigation of soybean with magnetized water improved its symbiosis with its specific rhizobium. Improved symbiosis increased plant seed yield and water use efficiency. Therefore, improved symbiosis by irrigating soybean with magnetized water can reduce the reliance on nitrogen fertilizer application in this plant. It can also improve the status of soil fertility for other crops in crop rotation.
M.H. Rad; M.H. Asareh; M.R. Vazifeshenas; A.R. Kavand; M. Soltani Gerdeframarzi
Abstract
Introduction: Although jujube (Ziziphus jujuba Mill.) is known as a medicinal plant and is less important than other fruit trees, it has received more attention in recent years due to its significance in traditional Iranian medicine. There is no study on the actual water need for jujube trees and the ...
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Introduction: Although jujube (Ziziphus jujuba Mill.) is known as a medicinal plant and is less important than other fruit trees, it has received more attention in recent years due to its significance in traditional Iranian medicine. There is no study on the actual water need for jujube trees and the impact of irrigation on yield and water use efficiency in the country. However, some studies emphasized on the need of regular watering and irrigation to improve the quality and quantity of jujube fruit. Given the importance of jujube in China, extensive researches have been conducted on water requirements, plant strategies to save water, impact of drought stress on plant morpho-physiological behaviors, impact of appropriate water distribution on soil quantity and quality of plant development, root distribution patterns and its impact on the amount of water consumed. In all cases, it has been emphasized that the mechanisms of water consumption in jujube differ by climate, genotype, irrigation method and management. In order to improve the quantity and quality of jujube fruit, it is necessary to balance the soil moisture condition and keep the plant away from stress. However, dehydration in jujube is a serious issue that should be addressed with the aim of saving water and improving fruit quality. In this study, the actual water requirement of the plant, the effect of different levels of deficit irrigation on evapotranspiration (ET) and crop coefficient (Kc) rate, yield and water use efficiency (WUE) in jujube trees were investigated. The moisture stress was applied through all stages of plant growth by deficit irrigation. Materials and Methods: In this study, the lysimeter experiment site of Yazd (Shahid Sadoghi Desertification Research Station) with 20 weighing drainage lysimeters (170 cm in height and 121 cm in diameter) was used. To measure evaporation from the soil surface, one lysimeter without plant was used. Note that the moisture content in this lysimeter was always maintained at the field capacity. For the measurement of reference ET (ET0), one lysimeter was used and it compared with ET0 calculated by Penman-Monteith-FAO. After preparing the lysimeters and providing the conditions for planting seedlings, we planted one tree per lysimeter. Trees collected from the villages of Alqoor, Flarg and Gyuk (South Khorasan Province). The suckers were two-years-old with the same size and shape. Trees were irrigated with 50 liters water on a weekly basis for six months. At the beginning of autumn of 2018, treatments including complete irrigation (field capacity), 30% and 60% of deficit irrigation were conducted in a completely randomized design with six replications. Soil moisture measurement during the experiment was performed by TDR. Soil moisture was recorded at 4 depths (0-30, 30-60, 60-90 and 90-120 cm) and their mean was considered as an index of soil moisture status to compensate the irrigation fraction. During the experiment and at the end, indices such as different stages of plant growth, ET, ET0, Kc, yield and WUE were determined. The data were analyzed by analysis of variance (ANOVA) using the statistical package SPSS ver. 16.0, and the mean values were also compared using LSD multiple range test (α = 0.05). Results and Discussion: The results showed that the jujube trees began their vegetative growth from late March (leaves appear) until the end of November (leaves fall) over 2017-2018 agronomic year in Yazd. During this time, which lasted about 235 days, four major and important stages were evident. The steps cited were in FAO's recommendation for deciduous fruit trees (in Issue 122 of the Iranian Irrigation and Drainage National Committee). The results of these studies showed that the length of different growth periods of jujube trees (including early stage, plant development stage, mid stage and end stage) was different with another deciduous fruit trees. ET values in three irrigation regimes showed that the highest ET was observed in July and the lowest in March. Annual ET in control, 30% and 60% of deficit irrigation treatments were 828.06, 514.04 and 386.04 mm, respectively, with 0.45, 0.28 and 0.21, annual Kc, respectively. The results of ET and Kc computed at different growth stages showed that the reproductive growth development period (flowering, fruit set beginning of fruit growth) had the highest ET. In control treatment, the lowest ET (60.81 mm) and Kc (0.27) were observed in early growth period with less than 10% of crown cover. The highest ET (316.22 mm) and Kc (0.60) were found in growth development period with full crown cover. Analysis of variance showed that there was a significant difference (P <0.0001) between the different irrigation treatments in terms of dry matter yield. There was a significant difference for WUE (P <0.001) between different irrigation treatments. Each of different irrigation regimes had a significant difference in yield. The highest yield for each tree was found for the control treatment with 229.36 g and the lowest yield with 57.90 g was observed for 60% deficit irrigation regime. There was no significant difference between control and 30% deficit irrigation treatment in WUE. The value of WUE decreased with increasing the drought stress. In 60% deficit irrigation treatment, WUE was 0.366 g fruit dry weight per liter denoting the significant difference between this irrigation treatment and the others. Conclusion: The results of this study showed that jujube trees were susceptible to drought stress in all four stages of growth, especially the period of growth coinciding with flowering, fruit set and early fruit growth. Hence, jujube trees yield and WUE seem to decrease under drought.
J. Nikbakht; V. Eshghi; T. Barzegar; A.R. Vaezi
Abstract
Introduction: In arid and semi-arid regions such as Iran, water shortage and soil absorbable nutrients deficiency are limiting factors of plants growth. Nutrient deficiencies are compensated by chemical fertilizers. The main issue in fertilizer consumption is to use the optimal amount of fertilizer that ...
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Introduction: In arid and semi-arid regions such as Iran, water shortage and soil absorbable nutrients deficiency are limiting factors of plants growth. Nutrient deficiencies are compensated by chemical fertilizers. The main issue in fertilizer consumption is to use the optimal amount of fertilizer that increases water and fertilizer use efficiency. One of the newest and most effective approach for efficient use of water in agriculture is to magnetize the irrigation water. For producing magnetized water, it is crossed through a permanent magnetic field. By crossing water through a magnetic field, its physical and chemical properties improve. The aim of current research was, investigating the effect of urea fertigation by magnetized water on yield, water and fertilizer use efficiency in cucumber cv. Kish F1.
Materials and Methods: This study was performed as split plot experiment based on completely randomized block design with three replications from June to November 2018 on cucumber cultivate Kish F1 at the Research Farm of Agricultural Faculty, University of Zanjan, Iran. The treatments consisted nitrogen fertilizer levels at 5 levels from urea source (0%, 25%, 50%, 75% and 100% crop fertilizer requirement) and irrigation water (magnetized and no magnetized water). The treatment of 0% urea fertilizer and no magnetized water were considered as control. For crops irrigation, tape-drip irrigation system was used and for magnetizing of water, an electromagnetic field with 0.1 tesla was used. The crop water requirements were calculated by FAO-Penman-Monteith Approach on a daily basis using on-time weather parameters data of Zanjan Station. The irrigation frequency was 3 days. During the growth period, fertilization was done as fertigation approach on four times (15%, 30%, 30% and 25% of total crop urea fertilizer requirement). The first fertilization was applied 45 days after planting and the rests was carried out as 10-day periods after first fertilization.
Results and Discussion: The effect of urea fertilizer levels were significant at 0.1% level on yield, water use efficiency, number of fruits and leaf area, at 1% on chlorophyll index and at 5% on fertilizer use efficiency. Magnetized water was significant at 0.1% level on the all evaluated traits, except chlorophyll index. Treatment interaction effects were significant on water use efficiency, urea fertilizer use efficiency and number of fruits at 1% and no significant effect on the rest of traits. Compared with control, the highest and lowest increase in mean chlorophyll index were in 75% and 0.0% urea fertilizer level and magnetized water (21.1% and 0.4% respectively). At any urea fertilizer level, mean leaf area in magnetized water treatment was greater than no magnetized water treatment. Maximum and minimum difference between magnetized and not magnetized water treatments were in 25% and 0.0% urea fertilizer level (155.8 and 143.6 cm2, respectively). Based on treatments interaction, maximum mean of fruits number, achieved in 75% urea fertilizer level-magnetized water (32.8 number). It was 47.7% more than control. Maximum mean of cucumber yields with 50.3 t/ha, were in 75% urea fertilizer level-magnetized water that it increased 17.9, 2 and 3.8 t/ha compared with control, 100% urea fertilizer level-magnetized and no magnetized water, respectively. Results showed that application of magnetized water to irrigate plants, increased water use efficiency. Maximum water use efficiency achieved in 25% urea fertilizer level and magnetized water as much as 17.7 kg/m3. The trend of variations in mean water use efficiency showed, in no magnetized water, by reducing the application amount of urea fertilizer, averages of water use efficiency decreased but in magnetized water treatment, the trend of variations were incremental from 100% to 75% urea fertilizer level. On results, at each level of urea fertilizer treatment, using magnetized water for plant irrigating, increased mean of fertilizer use efficiency compared no magnetized water treatment. Maximum difference between means of urea fertilizer use efficiency at magnetized and no magnetized water was achieved in 25% urea fertilizer level as 74.3 Kg/Kg (367%). The results also showed, the trend of variations in mean urea fertilizer use efficiency at no magnetized water were decreasing from 100% to 25% urea fertilizer level but at magnetized water, the trend was increasing.
Conclusion: based on results of the current research, the optimum urea fertilizer level in Zanjan Region for cucumber is 75% urea fertilizer requirement, which by applying magnetized water to irrigate cucumber plants, mean of yield increases. In this case, in addition to save 25% of urea fertilizer amount, it is also prevented environmental problems.
T. Raeisinejad; N. Yazdanpanah
Abstract
Introduction: Water has been known as an important limiting factor for plant growth and agricultural yields in arid and semi-arid regions. It is a significant input to agricultural production and also an essential requirement for domestic, industrial and municipal activities. Increasing population and ...
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Introduction: Water has been known as an important limiting factor for plant growth and agricultural yields in arid and semi-arid regions. It is a significant input to agricultural production and also an essential requirement for domestic, industrial and municipal activities. Increasing population and standards of living are contributing to a steep rise in demand for fresh water. By using proper irrigation management practices in farmlands, it is possible to utilize water, soil and fertilizer to produce high yield and quality products. Drip irrigation is considered as one of the most efficient irrigation methods. One of its major advantages is the ability to apply water to the soil as often as desired and in smaller quantity than the other irrigation methods. Two systems of drip irrigation including surface and subsurface drip irrigation methods have been widely used in arid and semiarid regions to reduce the water deficiency impact. Subsurface drip irrigation has been used for many years because of its effectiveness in reducing soil surface evaporation. It has been widely used in horticultural crops under both greenhouse and outdoor field conditions. However, the surface drip irrigation system can be used easier than the subsurface drip irrigation system. In addition, deficit irrigation is one of the strategies for efficient use of water and increasing water use efficiency in agricultural district. Deficit irrigation is a suitable solution to gain acceptable and economic performance by using minimum amount of water. The aim of this study was to evaluate the yield and yield components of sunflower affected by different levels of soil matric potential in combination with two contrasting drip irrigation method i.e. surface and subsurface. In addition, water use efficiency as an important criterion of yield was used to achieve the best and more suitable irrigation method under water scarcity conditions.
Materials and Methods: In order to investigate the irrigation management of sunflower, a field experiment was carried out during 2016 growing season at an experimental farm in Jiroft city. The treatments were laid out in split strip plots based on randomized complete block design with three replications. The treatments were comprised of three soil matric potentials of 40, 55, and 70 centibar for initiation of irrigation in the main plot and sub plots consisted of two drip irrigation systems (surface and subsurface). In the surface systems, drip lines were placed on the soil surface at a distance of 15 cm from the plant and in the subsurface systems, drip lines were placed at a depth of 30 cm. The irrigation time was determined based on the readings of metal tensiometers. These tensiometers were installed in three depths of 15, 30 and 50 cm of soil and at a distance of 20 cm from the plant. In this regard, in both irrigation systems, the mounted tensiometer at a depth of 15 cm of soil was used in the early growth and development, and mounted Tensiometers at depths of 30 and 50 cm soil were used in the middle and final stages of growth. In order to carry out irrigation at the potential point of view, the tensiometers were fully controlled and when the calibrated tensiometer screen showed the desired potential point, irrigation was carried out and the irrigation process continued until the soil moisture reached the crop capacity level. Yield, yield components such as number of seeds per head, along with water use efficiency were measured. Data were statistically analyzed using SAS Statistical software. Treatment means were compared using LSD test.
Results and Discussion: The results showed that the water usage parsimony of 153.6 mm (21.5 percent) between the 40 and 55 c-bar tensions caused that the yield, number of seeds per head and height of plant decreased by 12.5%, 12.8% and 11%, respectively, but water use efficiency increased 10.3%. Compared with 55 c-bar tention, 70 c-bar also decreased the yield, number of seeds per head and height of plant by 33.4%, 22.9% and 22.5%, respectively but increased water use efficiency by 4.7%. Moreover, the yield in subsurface drip irrigation increased by 499 kg/ha compared with surface irrigation. In addition, parsimony of water usage was 10% and water use efficiency increased by 21.5%. Number of seeds per head and the height of plant increased by 8.2% and 8.7%, respectively in subsurface drip irrigation.
Conclusion: According to the results of this study conducted on sunflower in Jirot area, it was concluded that the application of soil matric potential of 55 centibar in subsurface drip irrigation system is the best approach to increase water use efficiency during periods of drought.
Habib Abedi Babaheydari; Rohallah Fatahi Nafchi; Davood Namdar
Abstract
Introduction: The existence of 35 to 45 million hectares of desert areas in Iran and many restrictions such as lack of precipitation, have caused many challenges for the development of these areas. On the other hand, improper utilization of existing resources has resulted in desertification as a natural ...
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Introduction: The existence of 35 to 45 million hectares of desert areas in Iran and many restrictions such as lack of precipitation, have caused many challenges for the development of these areas. On the other hand, improper utilization of existing resources has resulted in desertification as a natural phenomenon, which is increasing annually. The activities that have been tracked down desertification decades ago have only managed to control a very small corner (about 9.1 million hectares) of these areas. Desertification is the consequence of two challenges of climate change and freshwater scarcity. In Iran, 43.7 million hectares are desert ecosystems in the wilderness of the country, of which about 20 million hectares of desert ecosystems are affected by wind erosion. Meanwhile, 4.6 million hectares in 183 districts in 82 counties and 18 provinces of the country are considered critical wind erosion centers. In general, natural and human factors are among the main origins of desertification. In arid and semi-arid areas due to lack of precipitation, water is the most important limiting factor for plant deployment. Due to the quantitative and qualitative limitations of water resources, the survival of plants in desert areas, mainly depends on the choosing appropriate irrigation method. The purpose of this study was to compare Water Box method, which is a particular form of irrigation, with surface and drip irrigations for planting hawthorn plant, which is often used for desertification projects in semi-arid areas such as Iran.
Materials and Methods: Experiments were carried out in the research field at Shahrekord University in the coordinate 32.3526° N, 50.8261° E and 2105 meters above sea level. The study area is 7 km far from the Shahrekord synoptic meteorological station. Shahrekord climate is categorized as Dcas climate by Copenhagen division method, which is characterized by moderate cold weather conditions with warm summers. In surface and drip irrigation methods, five irrigation regimes with zero, 25, 50, 75 and 90 percent of water requirements each with three replications were applied. In the Water box method, due to the self-regulation of the system and the no possibility of deficit irrigation, experiments with 15 similar replications were performed. Plant parameters such as stem diameter, height, seedling survival percentage and water content in each treatment were measured by one-month interval and compared to each other at the end of the study.
Results: The results of this study showed that the Water Box system, while significantly reducing the amount of consumed water (92% than drip irrigation) and high survival rate of seedlings (in this research 100%), is a useful method for establishing some hawthorn seedlings for combat and control of the desertification phenomenon. The highest growth was observed in irrigation treatments with 25 percent low irrigation with 60 cm height growth. Also, the lowest growth is due to irrigation with 90 percent low irrigation. In order to compare the mean annual growth rate of treatments, data were analyzed in SPSS software using the Duncan test at a significant level of 5 percent. The highest water use efficiency was related to water Box irrigation with 2.5 cc/l, which was obtained with a relatively large distance from other treatments, while, as mentioned in the previous sections, the water consumption of this treatment 92 percent low irrigation than full drip irrigation. The lowest water use efficiency was related to irrigation with 75% irrigation, which was 0.15 m3 l-1. In total drip irrigation treatment, water use efficiency was estimated to be 0.16 cm/liter, which shows that although the growth of this treatment was in good condition, it has poor results regarding water use efficiency.
Discussion: Due to the resistance of hawthorn to drought, only three of the cultivated seedlings were dried. The percentage of viability in the Water Box method was 100 percent. However, the difference in the percentage of vitality according to Duncan's method was not significant at 5 percent level. The results of seedling survival percentage were consistent with Naseri et al.(2005). They did not observe the significant difference between irrigation treatments in terms of viability. Due to the lack of research on irrigation with the Water box system, it is recommended that other researches be carried out on the use of this system for irrigation of other (productive) species. The location of the installation and tiling of wicks is one of the things that need to be addressed in the future research.
Fatemeh Fattahi-Naghani; Mahdi Ghobadinia; abdolrahman mohammadkhani; Mohamad reza Nori Emamzadeie
Abstract
Introduction: Change and decrease in atmospheric precipitation in recent years as well as increase in population and further demand for agriculture in the arid and semi-arid regions (such as Naghan) has led to a significant decrease in surface and groundwater resources. Therefore, achieving optimal utilization ...
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Introduction: Change and decrease in atmospheric precipitation in recent years as well as increase in population and further demand for agriculture in the arid and semi-arid regions (such as Naghan) has led to a significant decrease in surface and groundwater resources. Therefore, achieving optimal utilization of water in agriculture, new irrigation systems has been considered to gain the most crop yield with less amount of water consumption. Also cultivated area can be expanded by these systems, containing lands with irregular topography, due to the high water distribution uniformity. Besides developing irrigation system, irrigation management is an important tool for increasing crop productivity. Researchers have shown that applying deficit irrigation (DI) under drip system, has led to improve the quality of grape yield, decrease water consumption and increase water efficiency. The aim of this study is to investigate the effect of irrigation system and water stress on water consumption, yield and physiological indices of grapes.
Materials and Methods: The study field was located in Naghan, Chaharmahal & Bakhtiari Province, Iran. Experiences were done during summer 2016, in a completely randomized block design, with four replications in a grapevine garden The treatments included: CTRL, Furrow irrigation as common method in the area (control), surface irrigation with 100% water requirement (SI100), surface irrigation with 60% water requirement(SI60), drip irrigation with 100% water requirement(DI100) and drip irrigation with 60% water requirement (DI100).At the beginning of the experiences, 20 vine trees were selected with average of 60 years old. The field was divided into blocks, and the treatments were applied, randomly. Then the blocks were set up for the surface and drip irrigation. As the next step, required water was collected in a reservoir to obtain constant and reliable amount of water. In the control treatment, irrigation schedule of the gardeners (custom of the region) were considered in which irrigation event was at the beginning of the season. Also, drip and surface irrigation treatments were according to the soil water deficit. At the end of the experiment, water use efficiency, product performance, RWC, number of cubes per cluster, the weight of the cube in the cluster, cluster length, the number of main branches of the cluster and also qualitative properties such as soluble solids (Brix), total acid and pH of grape juice were measured.
Results and Discussion: According to the results of qualitative traits, the amount of applied water significantly affected the grapes pH in the level of 5%. The lowest grapes pH was due to the control treatment and the highest to the surface irrigation 60%. Also, measuring total soluble solids (TSS) in grape indicated significant difference in 1% level which revealed that deficit and drip irrigation increased sugar in grapes and therefore quality of the crop. The results of quantitative traits showed the number of cubes in treatments had a significant difference at a probability level of 1%. Number of cubes in surface irrigation treatment 100% (SI100) had the highest value, while the quality of the crop was lower. The treatments differed significantly in weight of 100 cubes and the drip irrigation treatment 100% (DI100) did not have a significant difference with control treatment, while deficit irrigation resulted in reducing the crop weight. Relative water content of leaves (RWC) had the highest amount in the control treatment, while low water stress reduced this index. Wet and dry yields were highest in the control treatments (CTRL); while, the lowest amount was due to the low irrigation treatments of DI60 and SI60 with 19% and 34% reduction, respectively for the wet and dry yield. Drip irrigation with 100% water requirement (DI00) was not significantly different from the control treatment in most of the quality parameters, cluster and yield characteristics but had less water consumption and higher water use efficiency.
Conclusions: Regarding the conditions of the region and the reduction of water resources, an accurate and efficient plan for irrigation is needed. So, the common method of irrigating in the region was assessed, as well as new methods of applying drip system and deficit irrigation. The results of this study indicate that drip irrigation system with 100% water requirement has no significant difference with the conventional irrigation method in the region, on quality and quantity of the gape yield. However, applying the drip system reduced the water consumption by 40%, and increased efficiency. Hence, drip irrigation system is suggested to be replaced by the traditional system.
Elham Madadi; Seyfollah Fallah
Abstract
Introduction: Drought stress is one of the most important limiting factors for plant growth in the arid and semi-arid regions. This stress affecting crop production such as maize (Zea mays L.). Maize can play an important role in providing forage for silage animals, especially in the winter season in ...
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Introduction: Drought stress is one of the most important limiting factors for plant growth in the arid and semi-arid regions. This stress affecting crop production such as maize (Zea mays L.). Maize can play an important role in providing forage for silage animals, especially in the winter season in most parts of Iran due to high production capability . The application of plant growth regulators such as jasmonic acid and humic acid is one of the fastest ways to increase crop tolerance to environmental stresses viz. drought stress. The role of these acids is to prevent aging and falling of leaves, hormonal effects and improve nutrient uptake, which leads to increase of root and shoot biomass. Due to the expansion of industrial livestock, maize silage supply is essential. On the other hand, maize pollination and grain filling occur in the summer season and it overlaps with the peak of water limitation. Thus, in this experiment, the effect of jasmonic acid and humic acid on morpho-physiological characteristics and water use efficiency of forage maize under drought stress were studied.
Materials and Methods: In order to investigate the effects of jasmonic acid and humic acid to mitigate the impact of drought stress during pollination of forage maize (KSC 704), an experiment was conducted in research farm of the Shahrekord University, in 2016. The experiment was performed as a split plot in a randomized complete block design with three replicates. The treatments consisted of different levels of drought stress (no drought stress (field capacity), moderate drought stress (0.75 field capacity) and severe stress (0.50 field capacity)) as main plots and plant growth regulators (without hormone, jasmonic acid and humic acid) as sub plots. In no hormone condition, distilled water was used. Foliar application was done 10 mM jasmonic acid and humic acid content of 1500 grams per hectare before maize flowering. The volume of water consumed for each irrigation was measured by contour system. In this experiment leaf relative water content (RWC), proline, chlorophyll content, carotenoids, leaf area index (LAI), leaf weight, stem weight, ear weight, forage yield and water use efficiency (WUE) were measured. The analysis of data was performed using SAS software. Mean comparisons of study characteristics were done by LSD test at the 5% probability level.
Results and Discussion: The results showed that the relative water content, proline, chlorophyll, carotenoids, leaf area index, shoot weight, ear weight, forage yield and water use efficiency were affected by drought stress conditions. Although drought stress was reduced forage yield and related traits, the use of jasmonic acid compared to the control and humic acid under mild stress was significantly increased relative water content (61.1 and 39.3 %, respectively), leaf weight (60.4 and 41.8%, respectively), stem (14.8 and 25.12%, respectively), ear weight (13 and 23.8%, respectively), proline content (16 and 32.1 %, respectively), forage yield (24.4 and 24.2%, respectively). Under severe stress conditions, jasmonic acid significantly increased relative water content of leaf, weight of leaf, weight of stem and leaf area index. Under severe drought stress, jasmonic acid and humic acid had no significant difference. It was observed that under non-stress conditions, jasmonic acid wasn’t effective on water use efficiency and humic acid showed a negative effect. Under moderate drought stress, jasmonic acid was effective with increase 21.15 %, in moderating drought stress for maize and under severe stress jasmonic acid and humic acid had no significant effect.
Conclusion: According to the results, the occurrence of drought stress during pollination has a significant effect on maize yield. So that the severe drought stress (50% soil moisture depletion) leads to decrease in yield of maize forage due to decrease weight of leaf and ear. Although the most positive results of the use of growth regulators on maize yield were obtained under non-stress (full irrigation), the effect of moderate drought stress was mainly observed on forage production on jasmonic acid. The positive effect of foliar application of jasmonic acid in reducing the damage of drought stress and increasing of water use efficiency under moderate drought stress indicated that the use of this hormone could be useful in increasing production and quality of maize silage.
Mohammad Reza Emdad; arash tafteh; saeed ghalebi
Abstract
Introduction: Simulation models have been used for decades to analyse crop responses to environmental stresses. AquaCrop is a crop water productivity model developed by the Land and Water Division of FAO. It simulates yield response to water of herbaceous crops, and is particularly suited to address ...
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Introduction: Simulation models have been used for decades to analyse crop responses to environmental stresses. AquaCrop is a crop water productivity model developed by the Land and Water Division of FAO. It simulates yield response to water of herbaceous crops, and is particularly suited to address conditions where water is a key limiting factor in crop production. It is designed to balance simplicity, accuracy and robustness, and is particularly suited to address conditions where water is a key limiting factor in crop production. AquaCrop is a companion tool for a wide range of users and applications including yield prediction. Aquacrop has high accuracy and performance for yield prediction than other models regarding to irrigation and fertilizer management base foundation. Using Aquacrop model for crop yield simulation in different soil and water managements has high accuracy and its use requires calibration and validation. The use of models saves time and cost and, if calibrated and validated, acceptable results are expected.
Material and Methods: This research was carried out in order to calibrate and validate the Aquacrop model for simulating wheat grain yield in the three selected pilots in Hamidiyeh province of Khuzestan province in two years of cultivation.In this regard, three different plots with a total area of about 10 hectares were selected in Hamidyeh region. Sampling, measuring and determining the parameters of soil, water, plant, irrigation management (information required for the Aquacrop model) and the existing conditions of the area were carried out.The climatic data required in Aquacrop model was collected from synoptic meteorological weather station of Ahvaz. Irrigation water quality with mean water salinity of 1.9 dS/m has a good quality for irrigation. In the first year, 5 irrigation events (with a total volume of 9500 cubic meters per hectare) are available to the wheat plant at different stages. In this regard, based on meteorological data and field and vegetation data that was taken from the field level in the first year, the Aquacrop model calibration and performance variations were carried out at different times of irrigation using a simulation model. In order to validate the results simulated by the model, the best scenario provided by the model in the second year was implemented at selected farm level and its results were compared with the simulation results by the model.
Results and Discussion: Aquacrop model calibrated for the first year and then compared for different scenarios of irrigation timing (3-6 irrigation event).The amount of grain yield and total in 4 irrigation intervals are not different with the corresponding values in 5 irrigation intervals. Irrigation rotations were considered in accordance with routine irrigation rotations of the region during planting, tillering, stemming, flowering and seed filling (5 turns) for 4 steps of irrigation step and for 3 irrigation stages, the tiller and stem elongation was deleted. The model showed that, using four irrigation timing is the most appropriate irrigation scenario. Using the results of the model with considering 4 irrigation times, wheat was planted in the second year for model validation. In the second year, the average of measured and simulated wheat grain yield was 3.8 and 4.4 t/h (with 14% error).Average values of total yield and simulated wheat seeds in 4 and 5 irrigation intervals were not different, while the amount of water consumed in 4 irrigation intervals decreased by 20% compared to 5 irrigation intervals. On the other hand, water use efficiency increased by up to 21% in 4 irrigation intervals compared to 5 irrigation intervals. Also, according to the simulation, it was observed that increasing the irrigation interval at the arrival stage, while not significantly increasing the grain yield and the total, did not increase the water use efficiency in order to increase the water consumption (one irrigation interval) Reduced. Considering 3 irrigation timing, the grain yield decreased by 15%. Due to the reduced yield in three irrigation intervals than the more irrigation intervals, this scenario is not recommended for performance reasons. So, according to the simulation, at least 4 irrigation intervals (during planting, stemming, flowering and seed filling) are recommended to maintain proper production level in existing conditions. Comparison of statistical indices between measured and simulation values of wheat grain yield in both years showed that the coefficient of correlation, normalized root mean square error (RMSE) and agreement index were 0.9, 0.14, and 0.89 respectively, which indicates the proper performance of the model for simulating yield of wheat for two consecutive years. The average grain yield of simulated wheat has been estimated at 3.8 ton / ha, which estimates 14% of grain yield less than actual experimental conditions compared to its measured value, indicating the accuracy and efficiency of this model in simulating wheat yield in the present situation. With considering 4 irrigation events, the water use efficiency of wheat grain yield increased by 0.7 kg/m3, which confirms the ability and accuracy of the Aquacrop model for simulating grain yield of wheat and also improving water use efficiency.
Conclusions: The results of this study showed that the simulation of wheat yield in the first year (2.6 t/ha) has a close proximity to the measured values of yield (3 t/ha). Also, validation of the model with changing conditions in the second year showed that the simulated yield of wheat (4.4 t/ha) also had a good agreement with its measured value (3.8 t/ha), which indicates the high accuracy of this model in simulating wheat grain yields every two years. Therefore, this model has the efficiency and accuracy in simulating wheat yield in research conditions.
Javad ramezani moghadam; yaser hosseini; Mohammad Reza Nikpour; atieh abdoli
Abstract
Introduction: The largest share of water consumption in Iran is related to the agricultural sector. Therefore, in order to save water resources, priority is given to reducing irrigation water consumption. On the other hand, reducing of water quality and salinization are the main problems which are commonly ...
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Introduction: The largest share of water consumption in Iran is related to the agricultural sector. Therefore, in order to save water resources, priority is given to reducing irrigation water consumption. On the other hand, reducing of water quality and salinization are the main problems which are commonly found in the areas with limited water resources. One of the most important effects of salinity is the reduction of yield and its inhibitory effects on plant growth and metabolism. Also, increasing salinity can reduce potassium, calcium and magnesium ions. One of the significant points regarding the effects of salinity stress is a significant decrease in the hydraulic conductivity of the roots, which leads to a decrease in the water use efficiency index. According to the food and agriculture organization (FAO), more than 40 percent of Iran's irrigated lands are affected by salinity stress, which is generally found in dry and semi-arid areas. Therefore, studying the combined effect of stress caused by salinity and water stress can be used to provide management solutions for irrigation and crop production.
Materials and Methods: This study was conducted in greenhouse laboratory at University of Mohaghegh Ardabili, Ardabil, Iran during August to November 2016. In this research, the effects of saline water on cherry tomato yield under water stress conditions were investigated. The applied treatments included irrigation with saline water (in two levels: S1=4ds/m and S2=7ds/m) and water stress (in three levels, irrigation at 40, 50 and 65% field capacity, respectively, I1, I2,I3). The experimental design used in this research was a completely randomized block design with four replications. On the other hand, in order to compare the plant yield under water stress and salinity conditions with non-stress conditions, control treatment with salinity characteristics less than 1ds/m and irrigation without water stress were used in three replications. In this experiment, cherry tomatoes were cultivated in the pots with diameter and height of 26 and 27 centimeters, respectively. The moisture meter (Model: PMS-714) was also used to measure soil moisture and determine the irrigation time. The most important parameters included cherry tomato yield, total evapotranspiration and water use efficiency index. It should be mentioned that analyses of the results were done by MSTATC software (Version: 2.10).
Results and Discussion: The results of this study showed that the interaction between two factors of water and salinity stress on the parameters was not significant, but the effects of salinity stress on yield, total evapotranspiration and water use efficiency (in two levels: 2% and 5%) are significant. Also, the greatest effect of salinity stress on cherry tomato yield was observed, so that by increasing the amount of irrigation water salinity from 4 to 7 ds/m, the yield was decreased by 27%. Also, the performance in salinity treatments of S1 and S2 decreased by 27.2% and 46.7%, respectively, compared to the controled treatment. Probably the reason for the yield reduction caused by decreasing in plant evapotranspiration and plant growth and metabolism. In addition, water use efficiency index in treatments of S1 and S2 decreased by 3.4% and 22.3%, respectively, compared to the controlled treatment. As it can be seen, the differences in water use efficiency between the control and S1 treatments were not significant. In this study, the average values of Ky (plant response coefficient to salinity and water stresses) were achieved 1.39, which was higher than the value that was reported by FAO for tomato plant under water stress conditions (equal to 1.05). This can be due to the significant effect of saline irrigation water on the yield of the tomato plants. Finally, based on the results of this research, it can be said that although salinity decreased yield significantly at 1% confidence level, in the coming years, with severe water resource constraints and increased costs for its preparation, this yield loss can be economical and feasible.
Conclusions: In this research, the effect of saline water on cherry tomato yield under water stress conditions was investigated. According to the results of this study, with increasing salinity of irrigation water from 4 to 7 ds /m, total evapotranspiration decreased by 10%. On the other hand, due to salinity stress, tomato yield was decreased to 27% in the most salinity levels of irrigation water compared to control treatment; one of the main reasons of which could be the reduction of total evapotranspiration in the growing season. In the end, the important point to note is that although, based on the results of this study, utilization of irrigation saline water decreased the yield, total evapotranspiration and water use efficiency by 27%, 8.9% and 19.2%, respectively compared to the control treatment, but in the near future, by increasing the water production costs and the quantitative reduction of water resources, even use of saline water is economically feasible and justifiable.
shekoofe najafabadi; mohammad reza Nori Emamzadeie; Mehdi Ghobadinia; Abdolrazagh Danesh shahraki
Abstract
Introduction: Water scarcity is the most important limiting factor in the production of crops in arid and semi-arid regions. Thus, actions for increasing the efficiency and productivity of farm water is inevitable. A large proportion of the water, used in irrigation, evaporates, so an effective solution ...
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Introduction: Water scarcity is the most important limiting factor in the production of crops in arid and semi-arid regions. Thus, actions for increasing the efficiency and productivity of farm water is inevitable. A large proportion of the water, used in irrigation, evaporates, so an effective solution for conserving water is to control the evaporation on arable lands. Nowadays using mulch or plastic mulch is common and it makes efficient use of water in furrow irrigation possible by conserving and storing soil moisture. Mulch does not let dry air contact topsoil and it also prevents topsoil from solar irradiance and reduces evaporation and maintain soil moisture. Recent research in order to economize on water use and irrigation efficiency and water use efficiency has led. Thus, regarding the problem of water scarcity, the objective of this research is to investigate the effects of evaporation suppressing monolayers on the efficiency of water consumption and growth indices of seed corn single cross SC 704 in an arid and semi-arid region.
Materials and Methods: This research was conducted in Shahrekord University during 2015. The experimental design was randomized complete block design with 6 treatments and 3 replications. The treatments include control treatment (uncovering) and transparent plastic wrap, black plastic, cotton gunny and white and blue pp woven fabric. Planting and growing operations were conducted due to agronomic principles. Changes in soil moisture within the root-zone during the season were measured by using thetaprobe and all operations by measuring the amount of irrigation water used in all experimental plots of each treatment were applied separately using flow measurement and the amount and time of each irrigation was determined and applied based on MAD=50 by supplying required water.
Results and Discussion: The measurement results showed that variance analysis of relative water content (RWC) and water efficiency under the impact of different coverings had a significance difference with p-value of 0.01. Also the amount of the dry matter and harvest index of corn showed significance with p-value of 0.05. Results showed that mulch at all stages of measuring the impact of increasing the leaf relative water content it could originate from growing trend of air temperature during the period. Under these treatments the plants are expected to experience more desirable conditions regarding maintaining and distributing of soil moisture in comparison with other treatments and the indicator. The highest amount of dry matter calculated is for the blue pp woven fabric treatment that shows the ideal growth conditions and appropriate performance of the plant under the impact of this covering and the lowest amount is for the cotton gunny treatment. Leaf area index (LAI) is one of the important growth indices. In flowering (anthesis) stage, the maximum amount of LAI is 5.08 for the blue pp woven fabric treatment. The minimum amount of LAI is 2.5 for the cotton gunny treatment and it is because of There macroporous coating that weed growth has been hindering plant growth. On the basis of the hundred seed weight, the heaviest weight is 18.18 for the white plastic treatment and the lowest weight is 13.46 for the indicator treatment. The highest amount of harvesting index (HI) is 53.97 for the transparent plastic treatment and the lowest amount is 41.12 for the black plastic treatment.The corresponding amount is an increase of 32 percent compared to control treatment. The reason of reduction of HI is the reduction of seed performance than biological performance in water scarcity. One of the indices for evaluating irrigation management is water efficiency. The highest amount of water efficiency is 2.6 and 2.7 kg/m3for the blue pp woven fabric and white pp woven fabric covering and it reduces water wastage in form of evaporation and causes water conservation. And it protects the top soil from solar irradiance.
Conclusion: This research was conducted at Shahrekord University to investigate the effects of various coverings on water efficiency and corn seed performance. Using covering causes temperature growth in the soil under the covering and it also causes further and fast plant growth. It reduces evaporation from topsoil. As a result, it causes soil moisture to be invariable and because of lack of light under the coverings, photosynthesis is impossible, thus, weeds could not grow. Blue pp woven fabric of mulch to mulch increased 42% dry matter was cotton sack. Mulches effect of the corn harvest index showed a clear plastic mulch to increase 32 percent harvest index compared to the control. Mulches blue pp woven fabric, white pp woven fabric, cotton gunny, black plastic and transparent plastic, respectively, increases of 92, 85, 28, 14 and 78 percent of water use efficiency were compared to control.Therefore, plants under the impact of blue pp woven fabric and white pp woven fabric coverings access more water and nutrients than the indicator treatment, so water efficiency increases. Using coverings has conserved moisture more in the top layers of soil by reducing evaporation form topsoil.
Zeyneb Fathi Tilko; Parviz Fathi; Farzad Hosseinpanahi
Abstract
Introduction: water scarcity is one of the primary problems in arid and semi-arid regions such as Iran. In these regions, increasing water productivity in agriculture sector is inevitable. Water productivity can be increased using the drip irrigation method and application of irrigation strategies such ...
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Introduction: water scarcity is one of the primary problems in arid and semi-arid regions such as Iran. In these regions, increasing water productivity in agriculture sector is inevitable. Water productivity can be increased using the drip irrigation method and application of irrigation strategies such as deficit irrigation. Potato is the major crop in Dehgolan plain. Researches have shown that the potato crops very sensitive to water stress. Sprinkler and furrow irrigation systems are common methods for irrigation of potato crop in Dehgolan plain. In this plain, the main supply for irrigation water is groundwater resources. Due to the falling water table in this plain, high sensitivity of the potato crop to water stress and low efficiency of current irrigation systems in the plain, the use of modern methods such as drip-tape irrigation system is inevitable. Drip tape irrigation is one of the efficient methods to increase water productivity of agricultural crops. In this method, determining the optimal drip tape placement in the soil and irrigation water depth are the important factors for obtaining maximum yield and irrigation water productivity of potato crop. The purpose of this study was to investigate the effect of drip tape placement depth and irrigation level on water productivity of the potato crop (Agria cultivar) in Dehgolan plain of Kurdistan province.
Materials and Methods: A field experiment was conducted to evaluate the effect of drip tape placement depth and irrigation water level on water productivity of the potato crop (Agria cultivar) in Dehgolan plain of Kurdistan province in spring season of 2014. The results of water quality analysis showed that the irrigation water has not any limitation to plant growth. The soil texture of the field was silty clay. The experiment was arranged in split plot design based on randomized complete blocks Design with three replications. The main plots and subplots included the irrigation water levels (60, 80, 100 and 120 percent of the potato water requirement) and drip tape placement depth (0, 5, 10 and 15 centimeters), respectively. At the end of the growing season, tuber yield of potato was measured. Measured data were analyzed using statistical software, R.Also, mean comparisons were done using Duncan's test.
Results Discussion: The results showed that the effect of irrigation water and drip tape placement on yield and water productivity was significant (P= 0.01%). The maximum yield and water productivity of this crop were related to 120 and 60 percent of crop water requirement, respectively. The results also showed that drip tape placement depth equal 15 cm was the depth when using drip tape irrigation system in Dehgolan plain. Economic analysis of different treatments showed that irrigation water depth equal 120 percent of the potato water requirement has higher Benefit–cost ratio than other treatments, but the water produced related to it is minimized. Since the Dehgolan plain faced with an intense water deficit and groundwater level of this plain has lost, so maximizing the amount of water produced in Dehgolan plain is inevitable. The results showed that the applied irrigation water depth equal 60 percent of potato water requirement and installation of irrigation tape at a depth of 15 cm can be achieved highest irrigation water use efficiency of potato in Dehgolan plain.
The result of this research indicated that tuber yield and water productivity of the potato crop under subsurface drip irrigation systems is higher than surface drip irrigation. The ability of subsurface drip irrigation in the improving of tuber yield could be attributed to the less water lost from the soil surface through evaporation. Subsurface drip irrigation allows maintenance of optimum soil moisture content in the root zone, which improved the water productivity.
Conclusion: The results show that the maximum tuber yield of potato was related to 120 percent of the potato water requirement. But the maximum irrigation water use efficiency was related to treatment water equal 60 percent of water requirement and drips tape placement depth equal 15 cm. As a result, recommended to increase the irrigation water use efficiency in Dehgolan plain, deficit irrigation strategies applied. The results also showed that the yield and water productivity of the potato crop in subsurface drip irrigation method is more than surface drip irrigation method. In this way the growth of weed and water loss through evaporation was very low and therefore the plant uses the greater amount of irrigation water.
A Rezaei Estakhroeih; S. Khoshghadam; M. Ebrahimi Serizi; A. Badiehneshin
Abstract
Water shortage is the most important factors on crop production in the world. Several methods of deficit irrigation are solutions for reduction of irrigation water. To understand the effects of conventional deficit irrigation and partial root zone drying treatments on yield, yield components and water ...
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Water shortage is the most important factors on crop production in the world. Several methods of deficit irrigation are solutions for reduction of irrigation water. To understand the effects of conventional deficit irrigation and partial root zone drying treatments on yield, yield components and water use efficiency of sunflower (Farrokh cultivar), one study was carried out. The research was conducted on Shahid Bahonar University of Kerman in the spring of 2011. A factorial experiment in a randomized complete block design with one control (full irrigation) and 18 deficit irrigation treatments in three replications was considered. Deficit irrigation treatments were: conventional deficit irrigation (irrigation with %80, %60 and %40 ETP) and partial root zone drying (irrigation with %80, %60 and %40 ETP). Every deficit irrigation treatment was conducted in three growth stage of sunflower (all periods of growth, vegetative growth stage and reproductive growth stage).The results showed that the conventional deficit irrigation treatments (irrigation with 80% ETP) in vegetative growth had the highest plant height, leaf area, leaf area index and head diameter. Also, the maximum biological yield equal to49054, maximum grain yield is equal to 9934/3 and maximum oil yield is equal to 2441/2 kg per hectare in the conventional deficit irrigation treatments (irrigation with 80% ETP) in vegetative growth occurred.The highest water use efficiency for grain yield is equal to 1/46,forbiological yield equal to7/21 and for dry forage yield is equal 5/7 kilograms per cubic meter of water. According to results,conventional deficit irrigation (irrigation with %80, %60 and %40 ETP) is recommended on based.
M. Gheysari; M.M. Majidi; seyed majid mirlatifi; M.J. Zareian; S. Amiri; S.M. Banifatemeh
Abstract
The response of root to water stress is one of the most important parameters for researchers. Study of growth and distribution of root under different irrigation managements helpsresearchersto a better understanding of soil water content, and the availability of water and nutrition in water stress condition. ...
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The response of root to water stress is one of the most important parameters for researchers. Study of growth and distribution of root under different irrigation managements helpsresearchersto a better understanding of soil water content, and the availability of water and nutrition in water stress condition. To investigate the effects of four levels of irrigation under two different deficit irrigation managements on the root length of maize, a study was conducted in 2009. Irrigation managements included fixed irrigation interval-variable irrigation depth (M1) and variable irrigation interval-fixed irrigation depth (M2). Maize plants were planted in 120 large 110-liter containers in a strip-plot design in a randomized complete block with three replications. Root data sampling was done after root washing in five growth stages. The results showed that the effect of irrigation levels on root length was significant (P
M. Khorramian
Abstract
Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation ...
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Introduction: North of the Khouzestan is one of the most important citrus production center. Usually border irrigation is used to irrigate citrus in this area. This system has generally low application efficiency. Several investigations in other arid region have demonstrated in addition to improved irrigation efficiency with low-volume pressurized irrigation systems, citrus trees have adapted with these new irrigation systems. However limited information exists on the performance of mature orchards converted from border surface irrigation to pressurized irrigation systems. Therefore, the current research was conducted to evaluate the feasibility of converting surface irrigation to pressurized irrigation systems on mature citrus trees in climate conditions of North Khouzestan.
Materials and Methods: This study was conducted during three years at Safiabad Agricultural Research Center to evaluate the yield of citrus trees and the quality of fruits for two Marss and Valencia varieties which grow 7 years previously with surface irrigation and converted to pressurized irrigation systems. The treatments consisted of six irrigation methods including Overhead sprinkle irrigation (OHSI), Under tree sprinkle irrigation(UTSI), Trickle irrigation(TI)(six 8 L/h Netafim emitters), Microjet irrigation (MI)(two 180 microjet were located under canopy near of the trunk at opposite sides of trunk),Bubbler irrigation(BI)(a single located under the canopy of each tree)andSurface irrigation(SI) method.Soil texture was clay loam well drained without salinity(ECe=0.69ds m-1), with 1.25 percent organic carbon. The experimental design was completely randomized design. The trees were irrigated during spring and summer seasons. For calculating irrigation water depth in TI, MI and BI systems, daily evaporation from a class A evaporation pan of the Safiabad weather station (nearby the experimental field) was collected, and evapotranspiration of the citrus trees was calculated applying a pan coefficient of 0.8. During the growth season, soil moisture content was measured before irrigation in root zone depth using weighing method at two points of the beginning and the end of the garden to obtain an average showing changes of the field moisture content. Applied water were measured with flow meter for OHSI, UTSI,TI, MI and BI methods and WSC flume for SI treatment. In middle January after fruit ripening, fruit yield was determined by harvesting all the fruits from six trees located in the center of each plot. Weight of fruits from every tree was recorded. Then, 3kilogram fruits per tree were randomly separated and peel thickness, diameter, weight, juice solid percent, total dissolved solids(TSS) and Citric acid were measured.
Results Discussion: The annual precipitation was 385,345, and 336 mm for 2004, 2005, and 2006 years, respectively. The mean temperature of June, July and August (the warmest months) for 2004, 2005, and 2006 was 45.6, 45.2 and 45.8°C. Higher temperature in third year caused to increase heat stress, so fruit yield decreased. Irrigation water consumption in OHSI and UTSI were among 15000 to 17000 m3ha-1. Continues contact of irrigation water contacting with leaves in OHSI causes the accumulation of salts on the leaf surface and leaf drop in harvest season. Consumed water in BI, MI and TI compared with SI method reduced by as much as 48.6%, 57.2%, and 58.4%, respectively. Because soil wetted area in BI, MI and TI methods were low and about 30 to 50 percent of soil area.
There were significant differences in citrus yield, water use efficiency (WUE) and quality in 1% and 5%, so that comparison of means in Mars variety showed that the yield of trees in TI and SI methods were significantly higher than UTSI method. On the other hand, fruit yield was similar in OHSI, MI, TI and SI methods. Valencia variety fruit yield was similar for in BI, MI, TI and SI methods in all 3 years, and significantly more than OHSI and UTSI although BI, MI, TI used only 48% to 58% of irrigation water compared with SI method. WUE under BI, MI and TI methods was enhanced by 2 to 3 times more than SI,OHSI and UTSI methods because consumed water decreased in BI, MI and TI about 50%. Fruit size and fruit weight of Marss variety in the OHSI and fruit size and fruit weight of Valencia variety in the OHSI, MI and SI were better than other systems and had a significant difference in 1% probability.
Conclusion: Overall results of this study indicated that it is possible to convert SI to BI, MI and TI methods in northern khouzestan orchards without decreasing in fruit yield and quality of citrus trees. Salt accumulation on leaf surface in OHSI method was caused to drop leaves in harvest season.
ali asghar ghaemi; B. Zamani
Abstract
Introduction: Barley is very important to feed humans, livestock, medical, industrial uses, especially in fermentation industries. In Iran, barley crop cultivation was nearly 1.4 million hectares withits production of 1.3 million tons in 2003 (2). Barelyis the oldest crops to environmental stresses such ...
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Introduction: Barley is very important to feed humans, livestock, medical, industrial uses, especially in fermentation industries. In Iran, barley crop cultivation was nearly 1.4 million hectares withits production of 1.3 million tons in 2003 (2). Barelyis the oldest crops to environmental stresses such as drought and salinity resistance (3).The different barely growth stages with extreme water requirement can benoted in germination stage, stem elongation, heading the production stage, the stage of flowering and seed production. Typically, for spring and autumn barely respectively 3 and 4 to 5 times irrigation is done during the growing season. The barley water requirement over its life is between 4 and 7 thousand cubic meters and 518 liters of water is needed to produce one kilogram of dry matter. Due to limited water resources and low rainfall in Iran, efficient use of water is absolutely essential and the maximum water utilization must be achieved by applying a minimum amount of water in agriculture. One of the ways to increase productivity in agricultural water is deficit irrigation.Deficit irrigation is an optimization strategy for water use efficiency in irrigation.The purpose of this study was to evaluate the simultaneous effect of fertilizer treatments (150, 225 and 75 kg/ ha) and water at three different levels (100%, 75% and 50% of crop water requirement) at different growth stages on leaf area index, weight fresh and dried herb and plant nitrogen concentration and the effect of irrigation and nitrogen fertilizer on yield, yield components and productivity of water use.
Materials and Method: This research was conducted in Shiraz University in fall 2012 to study the effect of interaction of deficit irrigation and nitrogen fertilizer on yield, yield component and water use efficiency and nitrogen concentration in different stages of barley (Bahman species) growth. This experiment were evaluated using a randomized complete block design with s plit-plot layout with three deficit irrigation treatments ( consisted of irrigation with 100% ,75% and 50% of crop water consumption use) and three nitrogen fertilizer treatments (included 75 kg/ha, 150 kg/ha and 225 kg/ha) with three replication. A total of 27 experimental plots were carried out. In each plot, 11-row barley with 30 cm spacing apart and 5 cm depth were planted by hand. Barley seeding rates on the basis of 200 kg per hectare were planted in each experimental plots in the first half of November.Nitrogen requirement was applied in three stages of the growth: 30% before cultivation, 40% in shooting stage and 30% in barleyclusterstage.Irrigation treatments included 100% = W1, in this treatment 100% treatment crop water requirement was estimated by neutron meter (this was the control treatment which received muchwater as neededand no water stress in all growth stages),75% = W2: in this treatment 75% of the crop water requirement was applied, and 50% = W3: the 50% of the crop water requirement plant was applied. During differentgrowth stages plant required data were collected and the parametersinclude: grain yield, biological yield, straw yield, number of grains per spike, spike per unit area, grain protein, harvest index, 1000 grain weight, number of unfilled and filled grain per spike and efficiency of water use were determined . Tests to determine the percentage of leaf nitrogen and protein was measured by kjeldahldevice(6405UV / VIS). The software SAS (version.9.1) was used to analyze data and graphs were drawn in Excel.
Results and Discussion: results showed that the highest yield,yield component was obtained on 100% irrigation and 225 kg/ha fertilizer treatments. Also it was observed that at the certain level of irrigation treatment by increasing the amount of nitrogen fertilizer the amount of this parameters will be increased.Result also showed that at the certain level of nitrogen fertilizer by decreasing water, the maximum plant response to the nitrogen fertilizer consumption will be decreased gradually in most cases, 225 kg/ha nitrogen fertilizer treatment caused most of crop yield parametersbut the differences of crop yield at this treatment with 150kg/ha nitrogen fertilizer treatment wasnot significant. Water use efficiency for 50% deficit irrigation treatment was 0.77 and for 100% irrigation treatment was 0.55. Regarding the results obtained from this study andexisting water crisis problem in Iran, it can be noted that the irrigation ofbarley should not be exceeded more than the 100% of crop water consumption use but using 75% of water requirement is suggestive. Also using 150kg/ha nitrogen fertilizer treatment is more suitable for the area.
Conclusion: This study was conducted in order to determinethe yield performance of barley (Bahmanspecies)inBadjgah (Fars Provience)using three different irrigation treatments of 100, 75 and 50 percent of crop water requirement (based on the total available water plant) and three nitrogen treatments include 225, 150 and 75 kg/ ha in the spring and autumn cultivation. In terms of deficit irrigation, during the growing season crop will interface with different intensities and durations of water stress. This tension changes in response to nitrogen fertilizer by plant that creates unpredictable and in some cases is not always the same.Statistical analysis showed that there are significant differencesbetweenthe different treatments of irrigation, nitrogen fertilizer and their interaction.Applying 75% of barley water requirement is suggestive. Also using 150kg/ha nitrogen fertilizer treatment is more suitable for the study area.
S.S. Nurbakhsh; M. Ghobadinia; A. Danesh-Shahraki; mohammad reza Nori Emamzadeie; R. Fatahi
Abstract
Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling ...
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Introduction: Nowadays, due to lack of water resources and increasing demand for water, agricultural water planning issues need further consideration. With proper planning and determination of irrigation depth and time, the effects of stress and yield loss on the plants are reduced. Irrigation scheduling is one of the most important factors in crop’s quality and quantity. The main objective of irrigation scheduling is to control crop’s water conditions in order to achieve its optimum yield level. So irrigation timing is the vital factor on which crop water stress and eventually yield's level are dependent upon. Moreover, irrigation timing is used in irrigation scheduling. The aim of this study was to evaluate the effect of irrigation time on water consumption, water use efficiency and yield of beans.
Materials and Methods: In order to observe the effect of the amount and the time of the irrigation on water consumption, yields rate and water use efficiency, the current research was carried out at the University of Shahrekord during the summer of 2012. The experiment was done as a completely randomized design with 4 repetitions consisting of irrigation time and the amount of irrigation in 4 and 2 levels (at 6, 8, 14 and 18) and (deficit irrigation, full irrigation), respectively. Beans seeds were planted in 32 similar vases with a diameter of 45 cm and height of 60 cm, in each experiment. Treatments were begun after 37 days from planting. Treatments were irrigated when the average moisture in the root zone was equal to the lower border of readily available water of full irrigation. At the end of the experiments, plants were completely harvested. Then the plant’s height, number of branches, numbers of pods per plant, pod and seed weight were measured.
Results and Discussion: Results showed that irrigating at different times during the day influenced water use efficiency, water consumption, seeds yield and number of pods in the bush. The water consumption was affected by irrigation time. Among full irrigation treatments, irrigation at 2 p.m. and 6 a.m. had the highest and lowest water consumption, respectively. The total amount of water used in irrigation at 8 a.m., 2:00 p.m. and 6 p.m. compared to 6:00 a.m. was increased by1.6, 9.5 and 4.1 percent, respectively. The results showed that irrigation at 2:00 p.m., caused a significant reduction in yield. Moreover, water use efficiency in 6 a.m. treatments had increased 18.5 percent more than that of the 2:00 p.m. irrigation treatment. The time of irrigation did not have a meaningful effect on bush height, the number of minor branches, the pod's length. The effect of the amount of irrigation water was meaningful on bush height, number of minor branches, seeds yield, the number of pods in the bush, pods length and seed weight. Seed yield at 8:00 a.m., 2:00 p.m. and 6:00 p.m. treatments has shown 0.29, 17.1 and 7.6 percent decrease in comparison with 6:00 a.m. irrigation treatment, respectively. Moreover, 100-seed weights were significantly affected by the irrigation time. The maximum and minimum weights of 100-seed weights were obtained at 6:00 a.m. and 6:00 p.m. irrigation, respectively. Analysis of variance showed that the number of pods per plant was affected by irrigation time. The maximum number of pods per plant was 101 which belong to the 6:00 a.m. treatment. In this experiment in the case of irrigation at 2:00 p.m., the number of pods per plant was significantly decreased in full and deficit irrigation. The results showed that although the irrigation frequency was the same, irrigation at maximum evapo-transpiration caused the plant to be under stress and the yield was reduced. In other word, it can be said that time of irrigation had no meaningful effect on the appearance and shape of the plant while it was effective in terms of the yield. Overall assessments showed that maximum of the measured features were obtained in the case of 6:00 a.m. treatment.
Conclusion: The results showed that irrigation at different times of the day and the applied water stress, reduced water use efficiency. These caused traits such as plant height; number of branches; number of pods per plant; pod and seed weight to be affected by the irrigation depth. Based on the results of this experiment it can be stated that, when there is no limit of water supply, it is recommended to irrigate in the early morning, before the steep slope of the temperature rise. However, in the situations with water shortage problems, is better to manage the water and the product.
Keywords: Bean, Deficit irrigation, Irrigation time, Water use efficiency
hojjat ghorbani vaghei; Hosseinali Bahrami; R. Mazhari; A. Heshmatpour
Abstract
Introduction: Maintaining soil moisture content at about field capacity and reducing water loss in near root zone plays a key role for developing soil and water management programs. Clay pot or porous pipe is a traditional sub-irrigation method and is ideal for many farms in the world’s dry land with ...
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Introduction: Maintaining soil moisture content at about field capacity and reducing water loss in near root zone plays a key role for developing soil and water management programs. Clay pot or porous pipe is a traditional sub-irrigation method and is ideal for many farms in the world’s dry land with small and medium sized farms and gardens and is still used limitedly in dry lands of India, Iran, Pakistan, the Middle East, and Latin-America. Clay capsule is one of porous pipes in sub irrigation that is able to release water in near root zone with self- regulative capacity. Watering occurs only in amounts that the plants actually need (this amount is equal to field capacity) and released water in near root zone without electricity or use of an automatic dispenser.
Materials and Methods: A study was carried out in 2013 on the experimental field of agriculture faculty of Tarbiat Modares University, to study the effect of two irrigation types on qualitative and quantitative characters in grape production (Vitis vinifera L.). In order to provide the water requirement of grape plant were used porous clay capsules for sub irrigation with height and diameter of 12 cm and 3.5 cm and dripper with Neta film type for drip irrigation, respectively. Porous clay capsules provided from soil science group at Tarbiat Modares University. In this research, the volume of water delivered to grape plants during entire growth period in two different irrigation methods was measured separately with water-meters installed at all laterals. The water consumption, yield production and water use efficiency were evaluated and compared in two drip and porous clay irrigation systems at veraison phonological stages. In the veraison stages, cluster weight, cluster length, solid solution and pH content were measured in grape fruits. Leaf chlorophyll content and leaf water content were also measured in two irrigation systems.
Results and Discussion: The results of fruit quality characteristics showed that cluster weight, cluster length, solid solution and pH content has not significant different at 5% level in two system irrigation. Also, the foliar analysis showed that chlorophyll content and relative humidity of leaf has not been affected in two irrigation systems. Meanwhile, irrigation types were significantly effect on water consumption and water use efficiency. The average water consumption and yield production with buried clay capsules and drip irrigation methods on grapevine plant were 4050 and 6668 M3.ha-1 and 14.2 and 14.8 Ton.ha-1 respectively. The reducing water consumption with buried clay capsules irrigation method in related to drip irrigation was 39% on grapevine plants. Meanwhile, the average yield production with buried clay capsules and drip irrigation methods on grapevine plant was 14.2 and 14.8 Ton.ha-1 respectively. Also, the statistics analysis show that the yield and component yield have not significant different at 5% level in the surface and subsurface irrigation. According to the water consumption and yield production, using buried porous clay capsules created a better water use efficiency than drip irrigation method. In other words, Iran has been localized at arid and semi arid and have huge water consumption in agriculture, and therefore it is necessary to optimize water consumption especially in agriculture using new technology. According to the results of this research, using buried porous clay capsules is recommended in order to optimize water consumption for grape plants in different place in arid and semi-arid regions of Iran.
Conclusion: The purpose of an efficient irrigation system is to apply the water in such a way that the largest fraction thereof is available for beneficial use by the plant. According to the experimental results reported here, it could be concluded that the reducing water consumption with buried clay capsules irrigation method in related to drip irrigation was 39% on grapevine plants. Meanwhile, the average yield production with buried clay capsules and drip irrigation methods on grapevine plant was 14.2 and 14.8 Ton.ha-1 respectively. Also, the statistics analysis show that the yield and component yield have not significant different at 5% level in the surface and subsurface irrigation. The final result, it could be concluded that the porous clay capsules have a good ability to providing water requirement of grape plant. The grape irrigation in huge area of Iran is doing with a traditional method and the authors of this work believe that porous clay capsules have a high water saving potential and good capability for irrigation of various types of crops.
Keywords: Grape plant, Porous pipe, Soil moisture, Water use efficiency, Yield
Sh. Ashrafi; Hossin Sadrghaen; J. Baghani
Abstract
In order to evaluate the effects of different levels of irrigation, crop densities and cropping patterns on corn (KSC700 variety) water use efficiency using subsurface drip irrigation system, three field experiments were carried out in 2005 and 2006 in Karaj. Experimental design was split plot design ...
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In order to evaluate the effects of different levels of irrigation, crop densities and cropping patterns on corn (KSC700 variety) water use efficiency using subsurface drip irrigation system, three field experiments were carried out in 2005 and 2006 in Karaj. Experimental design was split plot design based on randomized complete blocks with three replications. In the first experimental Field, main plots were Three irrigation levels: 50%, 75% and 100% ET and sub plots were three plant densities: 65000, 75000 and 85000 plant per hectare and sub-sub plots were two planting patterns: one and two row plants per bed. Results showed that increasing the levels of irrigation from 50% to 100% of the plant water requirement, has a significant effect on yield and yield components. Results obtained from two years experiment showed that irrigation levels of 50% and 100% ET had the minimum and maximum yield values of 3.65, 12.28 and 3.58, 12.89 ton per hectare in years of 2005 and 2006 respectfully. Calculation on water use efficiency showed that treatments located to 75% and 100% ET groups have maximum water use efficiency compared to 50% ET treatments. This means that corn is a plant which is highly sensitive to deficit irrigation. It is recommended in area where there is no limitation in water resources, application of 100% ET for maintaining crop water requirement is suggested. In area where water resources is limited, it is suggested to maintain only 75% of crop water requirement by using subsurface drip irrigation method for corn production.
H. Afshar; Hossin Sadrghaen
Abstract
In areas with limited water resources, one of the main goals of irrigation is to maximize the water per unit volume. In corn planting two major options for increasing of water productivity are plant density and growing pattern. In order to achieve the above goal in Corn” Karaj 700”, an study was ...
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In areas with limited water resources, one of the main goals of irrigation is to maximize the water per unit volume. In corn planting two major options for increasing of water productivity are plant density and growing pattern. In order to achieve the above goal in Corn” Karaj 700”, an study was conducted in strip split plots in frame of complete randomized block design with 3 replications in Khorasan Agricultural and Natural Resources Research Center for 3 years. Irrigation treatments were subsurface drip irrigation with 3 levels (50, 75 and 100 percent of full water requirement) in the vertical plots and plant density with 3 levels (65,75 and 85 thousands plants per hectare) in horizontal plots. In addition sub plots were including one and two rows planting pattern on 75 cm furrows. The results showed that irrigation water affected only on corn yield. The maximum yield in all three years was achieved by 100 percent of full water requirement treatment and the minimum yield was observed in 50 percent of full water requirement. The effect of subsurface drip irrigation on water consumption was not significant in the first year but it was significant in the last two years. The most water consumption was achieved by 100 percent of full water requirement treatment. Besides 3 levels of plant density and 2 planting types were not affected on water consumption. Plant height was affected by water quantity in 3 years furthermore this trait was affected by planting type in the second and third year. The maximum and the minimum of plant height were in 100 percent of full water requirement and 50 percent of of full water requirement respectively. The weight of 300 grains in different treatments was affected by planting type in the second year and in the third year this trait was affected by irrigation levels.
H. Afshar; Hossin Sadrghaen; hamid reza mehrabadi
Abstract
To decree evapotranspiration from soil surface and improving irrigation efficiency and reduce water usage in cotton cultivation , plastic mulch was applied in furrow irrigation. This study was performed as a split plot experiment in capability randomized complete block design, in 3 replications. The ...
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To decree evapotranspiration from soil surface and improving irrigation efficiency and reduce water usage in cotton cultivation , plastic mulch was applied in furrow irrigation. This study was performed as a split plot experiment in capability randomized complete block design, in 3 replications. The experiment was located in Khorasan Razavi –Kashmar- Kashmar agricultural research station and was applied in 2 years, 2004-2005. The treatments were consist of irrigation period at three levels ; 6, 9 and 12 days as main plot and plastic mulch at three levels I-black plastic mulch, II- white plastic mulch and III- control (without plastic mulch)as a subplot on furrow irrigation. Each treatment was irrigated up to field capacity. The results showed that application of plastic mulch used better water usage and black plastic mulch was more effective. Meanwhile The results showed that the use of plastic mulch had significant effect on reducing of weed growth, plant height increasing, yield and water use efficiency in respect with control.
S.H. Sadreghaen
Abstract
This study was conducted to determine the best micro irrigation system for pepper cultivation during two years. The goal of this study was water saving and reduction the disease progress (Phytophthora capsici) in the field condition. Experimental design was split plot based on randomized complete blocks ...
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This study was conducted to determine the best micro irrigation system for pepper cultivation during two years. The goal of this study was water saving and reduction the disease progress (Phytophthora capsici) in the field condition. Experimental design was split plot based on randomized complete blocks design with four replications. Three different drip irrigation methods; drip irrigation with in-line emitter tubes, drip irrigation (tape), and drip irrigation with porous pipes as main plot and three different amount of water (50, 75 & 100% water requirement) were as sub-plot. The result showed that the drip irrigation had the highest effect on disease control. The drip irrigation (tape) with 100% and 75% water requirement treatments had the lowest progress of Phytophthora capsici.In the first year the effect of irrigation method on yield and progress of Phytophthora capsici was significant. The effect of irrigation levels on the characteristics of plant except yield was no significant (α < 0.01), but the effect of irrigation methods on water use efficiency was significant (α < 0.05). The drip irrigation (tape) with 100% and 75% water requirement treatment had the highest water use efficiency. In the second year the effect of irrigation levels and irrigation methods on yield was significant (α < 0.05), but the effects of combination of irrigation levels and methods on yield was not significant. The drip irrigation (tape) with 100% water requirement treatment had the highest yield. The result in two years showed that the pepper is a sensitive plant to water deficit. The drip irrigation (tape) and 100% water requirement treatment had the highest yield (7214 Kg) and water use efficiency (1.311 Kg/m3). The result also showed that the porous pipes had no good efficiency. According to the results, the best option for pepper is drip irrigation (tape) with using 100% water requirement.
