,fatmeh hashami; Ali Shahnazari; mahmood raeini; ali ghadami firouzabadi; Ebrahim Amiri
Abstract
The research as reported in related to simulation by WOFOST, predominately focused on traditional methods of deficit irrigation such as terms of percentage in full irrigation conditions or as evaluation of growth and development in certain days after irrigation. Also it should be noted that not only ...
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The research as reported in related to simulation by WOFOST, predominately focused on traditional methods of deficit irrigation such as terms of percentage in full irrigation conditions or as evaluation of growth and development in certain days after irrigation. Also it should be noted that not only these researches was based on a year plants, but also there isn’t any research of sunflower. So, in this research the ability of the last version of WOFOST in simulating of sunflower in DI and PRD in %75 and %55 levels is carried out in contrast to FI in two continued year so that crop coefficient of sunflower could be calculated and by this, the productivity of yield in Sari agricultural and natural resources research field could be achieved. The results of calibrations showed that crop coefficient which depends on weather, coordinates of region and physiologic and phonologic of plant is fixed among the simulation and irrigation coefficient are depend on irrigation treatment and their response in development of growth stages. Also the results showed that by decreasing the volume of water which given to plant, AMAXTB and KDIFTB decreased and adversely EFFTB is increase. Simulated seed yield and total biomass had normalized root mean square error (nRMSE) index less than 10%, coefficient of residual mass (CRM) index near zero, modeling efficiency (EF) about 0.98, correlation coefficient (R) about 0.96 and totally comparing the simulation and observation parameters showed that in the most statistical test done in the present study, the result in acceptable range which represented that WOFOST could be able to simulate the responses od sunflower in DI and PRD treatments by calibrated coefficient.
kourosh majdsalimi; b. salavatian; e. amiri
Abstract
Introduction: Designing and management of sprinkler irrigation systems depend on the situation and location of its implementation and often rely on professional and long-term tests (9). Having a good irrigation system depends on knowledge of the relationship between soil, water, plants, irrigation scheduling, ...
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Introduction: Designing and management of sprinkler irrigation systems depend on the situation and location of its implementation and often rely on professional and long-term tests (9). Having a good irrigation system depends on knowledge of the relationship between soil, water, plants, irrigation scheduling, the required amount of irrigation water to the water-holding capacity of soil, climate and plant growth (6).The less use of sprinkler irrigation systems and less performed research projects in the Guilan province, lack of correct design parameters due to shortage of the required parameters for local and regional planning, has led to reliance on charts and tables. Therefore, planning water resources cannot be performed well and with accurate details. According to many researchers (8), the technical evaluation should be a regular and short-term process to review the problems and possible performance of irrigation systems. Merriam and Keller (10) defined the assessment of an irrigation system analysis, based on field measurements in real terms during the normal work of the system. Therefore, to develop these systems over the next few years, it is essential to evaluate the use of irrigation systems and review the performance of existing problems and utilizing the results to improve it. The aim of this study was to assess the current status of implemented irrigation systems in the tea plantations of Guilan and evaluate their performance.
Materials and Methods: In this study, six classic sprinkler irrigation systems in tea fields of Guilan province were evaluated during two years. Sprinkler irrigation systems of semi-portable, solid-set and solid-set (hand-move sprinkler) were selected randomly. To evaluate this irrigation systems, Christiansen’s uniformity coefficient (CU), distribution uniformity (DU), potential application efficiency of low-quarter (PELQ) and application efficiency of low-quarter (AELQ) in the form of trial blocks were estimated by measuring pressure fluctuations which were applied to the entire system. Using irrigated area and irrigation water depth, adequacy of irrigation curve, deep percolation losses and spray losses were determined on the basis of existing relationships.
Results and Discussion: Average values of CU, DU, PELQ and AELQ for 6 tea fields were 65, 52, 44 and 44 percent, respectively. Application efficiency in all irrigation systems, Christiansen’s uniformity coefficient and distribution uniformity were lower than recommended values in the references. Merriam and Keller (11) reported the allowable range for potential application efficiency of low-quarter between 65 to 85 percent. With respect to irrigation less than the actual water requirement of the plant in tea fields, AELQ was equal with PELQ. Untechnical design and implementation of irrigation systems, particularly poor operating pressure and economic problems were detected as the main reasons for the low PELQ. Simultaneous use of sprinklers with different specifications and models, old irrigation systems, water leakage from valves and other equipment, practically change the pressure and flow rate, which were the main reasons for the decrease in uniformity of water distribution and application efficiency of low-quarter. According to Cobban (4) uniformity coefficient of sprinkler irrigation systems were reported between 31 to 55 percent in Tanzania tea fields and in other reports were between 58 to 72 percent (7), which was due to poor design, long spacing of sprinklers and high speed wind. Christiansen’s uniformity coefficient and distribution uniformity of low-quarter in ED, WB & EP systems were lower than recommended values by Merriam and Keller (%81≥CU≥87% & %67≥DU≥80%)(10). In spite of the little losses in deep percolation, irrigation adequacy of these systems was relatively low and unacceptable. In such circumstances, only about 20 to 38% of irrigated area in WA and CK systems, respectively received the required water or more, according to lack of soil moisture (required irrigation depth). The main reason was low uniformity of water distribution in irrigation systems which was described previously. Evaluated spray losses in irrigation systems was variable between 4.8 to 13 percent. The losses obtained in irrigation systems in tea fields in comparison with the values 2.6 to 42.4 which were obtained in other regions of the country were less by (1, 3, 5 and 12) due to low wind speed and high relative humidity (2) as the main reasons.
Conclusion: Average values of CU, DU, PELQ and AELQ for 6 tea fields were 65, 52, 44 and 44 percent, respectively that were lower than recommended values in the references. The results showed that old irrigation systems in tea fields are not in good functional status due to untechnical design and implementation, operation, exploitation and inappropriate maintenance (due to economic problems and lack of farmer’s knowledge on irrigation). To improve the performance and efficiency of irrigation systems in the tea fields, detailed information are recommended, to design and implement with detailed information accomplished by regional companies. Moreover, the use of solid-set (hand-move sprinkler) sprinkler irrigation instead of semi-portable with manual handling (aluminum pipes), operation of irrigation groups and promoting farmers' knowledge about the principles of proper the scheduling and management, operation and maintenance of irrigation systems are very effective to improve the performance indices.
A. Abdzad Gohari; E. Amiri; K. Majd Salimi
Abstract
Abstract
In order to investigate the effect of irrigation and nitrogen fertilizer, on yield peanut plant, with furrow method of irrigation and water use efficiency (WUE) in management to create a proper and better production, split plot experiment was over taken as in complete randomize blocks with ...
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Abstract
In order to investigate the effect of irrigation and nitrogen fertilizer, on yield peanut plant, with furrow method of irrigation and water use efficiency (WUE) in management to create a proper and better production, split plot experiment was over taken as in complete randomize blocks with three replications and main plot with 6, 12 and 18 day interval irrigation and no irrigation and subplot of nitrogen Fertilizer with amount 0, 30, 60 and 90 (kgN/ha) in the year 2009 in Astaneh Ashrafiyeh in Guilan province. The results of this investigation showed that in irrigation management, the maximum yield for the seed are in 6 day interval irrigation with total water use 328 mm has the highest pod yield 4093 and seed yield 2345 (kg/ha) Among the amounts of nitrogen also, the fertilizer amount of 60 (kgN/ha) with pot yield of 3376 (kg/ha) and the seed yield of 1796 (kg/ha) were the highest. The WUE for peanut as for pod and seed yield under irrigation, with 6 day interval irrigation for seed, pod and biomass have 0.71, 1.24 and 2.88 (kg/m3) of other irrigation management more, the amount of nitrogen 60 (kgN/ha), for seed, pod and biomass have 0.62, 1.21 and 2.58 (kg/m3) of other management higher than. Also the 6 day irrigation and without irrigation, the amount of 96 and 76 percent, have the highest and the least amount of RWC. Also the management irrigation and nitrogen fertilizer was effect on total biomass, weight of 100 seeds and harvest Index.
Keywords: Peanut, Irrigation, Nitrogen fertilizer, Water use efficiency, Yield
E. Amiri; M. Rezaei; M. Bannayan Awal
Abstract
Abstract
To evaluated ORYZA2000 model in Iran, this study was carried out during 2004 till 2007 at Rice Research Institute of Iran, Rasht. The experiment was conducted as split plot in complete randomized block design and three replicates. Three irrigation levels were the main plots and four levels ...
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Abstract
To evaluated ORYZA2000 model in Iran, this study was carried out during 2004 till 2007 at Rice Research Institute of Iran, Rasht. The experiment was conducted as split plot in complete randomized block design and three replicates. Three irrigation levels were the main plots and four levels of N application were allocated sup-plots model. Simulated and measured values leaf area index (LAI) and biomass of leaves, panicles, total aboveground biomass and crop N dynamics, was evaluated by adjusted coefficient of correlation; t-test of means; and absolute and normalized root mean square errors (RMSE). Results show that, with normalized root mean square errors (RMSEn) of 5–51%, ORYZA2000 satisfactorily simulated crop biomass and N uptake that strongly varied between irrigation and nitrogen fertilizer. Yield was simulated with an RMSE of 155–464 kg ha-1 and a normalized RMSE of 3–11%. Simulated LAI generally exceeded measured at low rates of nitrogen application. Results show that, ORYZA2000 could be used successfully to support N and irrigation management under the limited conditions.
Keywords: Rice, Model, Evaluation, Nitrogen, Irrigation
M. Rezaei; M. K. Motamed; A. Yousefi; E. Amiri
Abstract
Abstract
In order to study the effects of different irrigation management on water productivity of local, improved and hybrid rice varieties an experiment was carried out on a split plot design with 3 replications. The varieties were splited on 5 irrigation methods (i.e. full irrigation, AWD, 5, 8 and ...
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Abstract
In order to study the effects of different irrigation management on water productivity of local, improved and hybrid rice varieties an experiment was carried out on a split plot design with 3 replications. The varieties were splited on 5 irrigation methods (i.e. full irrigation, AWD, 5, 8 and 11 day irrigation interval) at Rice Research Institute of Iran, Rasht during cropping season of 2006. The results showed that interval irrigation reduced water use. Full irrigation with 593 mm had the highest water use and 11 day interval with 406 mm the lowest. Yield in hybrid, improved and local varieties were 6147, 5147 and 3987 kg/ha respectively. Results showed that yield loss in the varieties due to water stress (full irrigation, 5, 8 and 11 day interval irrigation) in hybrid were 9,19,23 and 44 percent, in improved were 14, 19, 23 and 29 percent and in local variety were 5,4,10 and 17 percent respectively. Local variety was the most resistant and hybrid was the most susceptible variety.
Keywords: Intermittent Irrigation, yield, water productivity, rice
