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parvin zolfaghary; Abutaleb Hezarjaribi; Mohamad Esmail Asadi; Ebrahim Amiri
Abstract
Rice is one of the important food products that is generally transplanted. The rice “dry seeding method (DSM)” is a new approach that has provided an opportunity to increase water productivity. In this research, changing the cultivation method from transplanting to DSM and using pressurized ...
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Rice is one of the important food products that is generally transplanted. The rice “dry seeding method (DSM)” is a new approach that has provided an opportunity to increase water productivity. In this research, changing the cultivation method from transplanting to DSM and using pressurized irrigation instead of flooding method was studied in 5 rice fields in Golestan Province. The field with flood irrigation method was considered as the control treatment. Other fields were cultivated in dry soil and irrigated by drip and sprinkler methods. The results showed that, in all parameters related to grain yield and yield components, the field with flood irrigation method had higher values. Economic study at the different growth stages with different irrigation methods showed that by changing the planting method and removing the puddling in rice field, 4000 to 7000 cubic meters of water can be saved. Comparison between different irrigation methods showed that the sprinkler irrigation had a higher average yield (4998 kg/ha) than drip irrigation) 4426 kg/ha(. With 30% yield reduction, this method saved 61% in water use, which is a significant amount. The highest and lowest physical (0.53 and 0.3 kg/m3) and economical productivity rates (141,791 and 82,704 Rials/m3) were related to sprinkler irrigation and flood irrigation, respectively, which show very low water productivity in the rice fields of the province. This shows the need to increase water productivity under the current climatic conditions of the country.
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Faranak Baradaran-Hazaveh; Hossein Babazadeh; Ebrahim Amiri; Hossain ebrahimi
Abstract
Pulses have a special position, after wheat and rice, in the Iranian people diet. The growth of these plants is very fast and water stress has an important effect on their yield. The objective of this study was to evaluate the DSSAT Model in simulating the growth and yield of cowpea under different levels ...
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Pulses have a special position, after wheat and rice, in the Iranian people diet. The growth of these plants is very fast and water stress has an important effect on their yield. The objective of this study was to evaluate the DSSAT Model in simulating the growth and yield of cowpea under different levels of irrigation water. An experiment was conducted as a randomized complete block design (RCBD) with three replications in Kiashahr City, Iran, in the crop seasons of 2017 and 2018. The main treatments included irrigation with management of 40%, 60%, 80%, 100%, and 120% of plant water requirement and the three sub-treatments included irrigation at vegetative or reproductive stages, and full irrigation. In this experiment, the DSSAT simulation model was used to evaluate water efficiency and water balance components. Evaluation of simulated and measured values of grain yield was performed using the parameters of coefficient of determination, t-test, root mean square error (RMSE) and root mean square normalized error (nRMSE). The results showed that the difference between the predicted grain yield and the observed values was acceptable (RMSE=92 and nRMSE = 12.62%). Total biomass was also well simulated (RMSE=130 and nRMSE = 5.91%). Using the measured grain yield and water balance components simulated from the DSSAT model, the water productivity based on evapotranspiration (WPET) was about 33% lower than that based on transpiration (WPT). According to the results, irrigation with 100% water requirement at both vegetative and reproductive stages resulted in the highest transpiration (383mm), and was selected as the optimum irrigation management during the growing season.
Pooya Aalaee Bazkiaei; Behnam Kamkar; Ebrahim Amiri; Hossin Kazemi; Mojtaba Rezaei
Abstract
This study was carried out to investigate the effects of irrigation intervals and different planting dates on the yield and yield components of rice. A split-plot design based on randomized complete block design was used with three replications, at Rice Research Institute of Iran (Rasht) in 2016 and ...
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This study was carried out to investigate the effects of irrigation intervals and different planting dates on the yield and yield components of rice. A split-plot design based on randomized complete block design was used with three replications, at Rice Research Institute of Iran (Rasht) in 2016 and 2017. The main factor was irrigation at four levels (full flooding, 5, 10 and 15 days irrigation intervals) and the secondary factor was planting date at three levels (April 21, May 11, and May 31). The results of analysis of variance showed that irrigation and planting date had a significant effect on the yield of rice at 1% probability level. The highest amount of biological yield was obtained in full flooding and 5-day irrigation interval, with an average of 10960 and 10238 kg/ha, respectively, and in May 11 and April 21 planting dates with an average of 10553 and 10397 kg/ha, respectively. The highest 100-grain weight was obtained in May 11 and May 31 planting dates, the maximum number of panicle per plant was observed in full flooding treatment, and in May 11 planting date and the highest number of filled grains was observed in full flooding treatment. The maximum number of hollow grains was observed in 15 and 10-day irrigation intervals and May 31 planting date. The results showed that the full flooding irrigation with a yield of 4271 kg/ha had the highest grain yield. The 10 and 15 days irrigation intervals had less grain yield than flood treatment and 5-day irrigation interval treatments. In two years of the experiment, the planting date of May 11 had the highest grain yield with an average of 3820 kg/ha. In this experiment, the May 11 planting date had the most favorable environmental conditions for growth and had a good yield-stability.
Alireza Nouralinejad; Ebrahim Amiri; Hossein Babazadeh; Hosein Sedghi
Abstract
This research was conducted to determine the production function of common bean and cowpea and evaluation of water use efficiency in Astaneh Ashrafiyeh, in 2016 and 2017. The present study was conducted as split plot in a randomized complete block design with 3 replications. Main treatments consisted ...
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This research was conducted to determine the production function of common bean and cowpea and evaluation of water use efficiency in Astaneh Ashrafiyeh, in 2016 and 2017. The present study was conducted as split plot in a randomized complete block design with 3 replications. Main treatments consisted of irrigation of 40%, 60%, 80%, and 100% of water requirement of the plant, and nitrogen treatments in sub plots consisting of no fertilizer, 30, 60, and 90 kg N ha-1 and two bean varieties (ordinary beans and cowpea). The results showed that the effects of irrigation and nitrogen fertilizer on seed yield and other agronomic traits were significant (P< 5%), in 2016 and 2017. Two-year average seed yield in 100% water requirement and 60 kg N ha-1 treatments in common bean and cowpea cultivars were 3446 and 3646 kg ha-1, respectively. The highest water productivity in 2016 and 2017 was obtained for the interaction of cultivar and irrigation on seed yield, and was 0.48 and 0.47 kg m-3, respectively. Water use productivity of the interaction between nitrogen fertilizer and bean cultivars in 2016 and 2017 in 100% water requirement treatment and 30 and 60 kg N/ha was between 0.42 and 0.46 kg m-3. The results of the estimation of production function indicated that the seed yield increased with nitrogen fertilizer application up to 30 kg ha-1, but with gradual increase in nitrogen fertilizer, the yield decreased. Based on the present study, 100% water requirement for seed yield can be recommended for both bean cultivars, however, the amount of fertilizer should be 60 kg N/ha for common bean and 30 kg N/ha for Cowpea.
Ali Abdzad Gohari; ebrahim amiri
Abstract
The inputs of water and fertilizer are important in agricultural production, with a shortage of each one reducing the yield of the product. The role and importance of each of the factors of water and fertilizer separately can be effective in increasing yield. The purpose of this study was to evaluate ...
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The inputs of water and fertilizer are important in agricultural production, with a shortage of each one reducing the yield of the product. The role and importance of each of the factors of water and fertilizer separately can be effective in increasing yield. The purpose of this study was to evaluate the effect of irrigation and nitrogen fertilizer on production function and water productivity in peanut plant in Guil cultivar. The experiment was conducted as a split plot based on randomized complete block design with 3 replications, in 2009 in Astaneh Ashrafiyeh. The main treatments included: without irrigation (control) and irrigation with intervals of 6, 12, and 18 days, while the sub treatments were nitrogen fertilizer rates of 0, 30, 60, and 90 kg ha-1. A quadratic equation was used to estimate the water-fertilizer production function. The results of production function estimation indicated that seed yield increased with nitrogen fertilizer up to 60 kg ha-1. But, with a gradual increase in nitrogen fertilizer, yield was reduced. Increasing nitrogen fertilizer from 60 kg ha-1 in different amounts of water consumed had no effect on yield increase. Water productivity and the water utilization rate in the irrigation interval of 6 days, with consumption of 328 mm, was the highest. In the irrigation interval of 6 days and consumption of 60 kg N-fertilizer ha-1, the maximum amount of water productivity was 0.96 kg m-3.
Hassan Ebrahimi rad; hossin babazadeh; ebrahim amiri; hossin sedghi
Abstract
It is necessary to optimize productivity and usage of available water resources due to shortage of these resources and low irrigation efficiency in rice fields. In order to study the effect of different irrigation managements and planting densities on rice, cv. Hashemi, an experiment was conducted in ...
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It is necessary to optimize productivity and usage of available water resources due to shortage of these resources and low irrigation efficiency in rice fields. In order to study the effect of different irrigation managements and planting densities on rice, cv. Hashemi, an experiment was conducted in a randomized complete block design (RCBD) with three replications at Koshal-Lahijan, in north of Iran, during cropping seasons of 2014 and 2015. There were 5 levels of irrigation treatments in this research including: I1 = Submerged irrigation, I2 = Saturation, I3 = Irrigation with 8 days interval before anthesis, I4 = Irrigation with 8 days interval after anthesis, I5= Irrigation with 8 days interval throughout the growing season). Also, there were 3 levels of planting density including, D1=15×15, D2=20×20, and D3=25×25 cm. Combined variance analysis showed that the effect of water stress and plant density on measured traits were significantly different (p<0.01). I1 had the highest yield in all treatments during the growth season, which was equal to 4151kg. Yields of I2, I3, I4, and I5 were equal to 4054, 3949, 3244, and 2787, respectively. Water productivity values of I3 and I5 were equal to 1.90 and 1.45 kg.m-3, which were the maximum and minimum (irrigation + rain) water productivity based on biomass. The results also showed that irrigation with 8 days interval before anthesis decreased water use by 16%, but it caused only 4% yield reduction. Analyzing different crop densities showed that yield components increased in high density (D1), while yield per unit area and water productivity decreased when plant densities decreased (D3). So, (D2) is the optimum spacing and is recommended.
z s; m d; mehdi panahi; E A
Abstract
Effects of six irrigation treatments on vegetative characteristics, yield, and sugar content of sugar beet and water use efficiency were investigated. The experiment was conducted at Aleshtar in Lorestan province during growing seasons of 2014 and 2015, using a randomized complete block design. Irrigation ...
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Effects of six irrigation treatments on vegetative characteristics, yield, and sugar content of sugar beet and water use efficiency were investigated. The experiment was conducted at Aleshtar in Lorestan province during growing seasons of 2014 and 2015, using a randomized complete block design. Irrigation treatments consisted of full irrigation (T1) as the control, T1 +cutting off the last irrigation (T2), 10% higher than the control (T3), 10% less than the control (T4), 20% (T5) and 30% less than the control (T6). The results of combined analysis of variance showed that the effects of different irrigation treatments on leaf area index, tuber dry weight, root yield, biomass, sugar content, sugar yield and water use efficiency on the basis of sugar yield was significant at 1% level. However, their effects on leaf dry weight and water use efficiency on the root yield basis was significant at 5% level. Although there were no significant differences between T2, T3, and T4 treatments in terms of crop vegetative characteristics, root yield, biomass and sugar yield, they increased these characteristics significantly compared to T5 and T6 treatments. Also, the highest water use efficiency on the basis of both root and sugar yield was obtained in T2 and T4 treatments. Therefore, to conserve water in sugar beet production in Lorestan province, decreasing the amount of water up to 10 % at each irrigation during the growing season or cutting off the last irrigation is recommended.
Z SAADATI; NADER PIRMORADIAN; E AMIRI; M REZARI
Abstract
In order to increase water productivity, a good understanding of crop response to water stress and tools which simplify the complex crop response to various environmental factors, especially to water, are needed.Simulation models that clarify the effects of water on crop yield are useful tools for improving ...
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In order to increase water productivity, a good understanding of crop response to water stress and tools which simplify the complex crop response to various environmental factors, especially to water, are needed.Simulation models that clarify the effects of water on crop yield are useful tools for improving farm level water management and optimizing water productivity. In this study, the WOFOST model was used to simulate two local rice varieties yield response under five irrigation treatments consisting of continuous flooding and irrigation at 0, 3, 6 and 9 days after disappearance of water from the soil surface. The experiment was conducted at Rasht region during two growing seasons of 2003 and 2004. The model was calibrated using the first year data and was validated using the second year data set. According to the results, the relative root mean square errors of grain yield simulation were 12.57% and 5.01% for Binam and Hasani cultivars in 2003, respectively. These values were 7.94% and 13.71% in 2004, respectively. The values of the observed and simulated water productivity based on precipitation and consumed water were close together. The results showed that the WOFOST model could simulate the effect of water on rice yield and water productivity in a humid region. Therefore, this model can be used to explore optimum management options to improve rice water productivity.