A. Sheini-Dashtgol; Saeid Boroomand Nasab; AbdAli Naseri
Abstract
Introduction: Sugarcane fields of the southwest of Iran have heavy soil texture, high temperatures, hot and dry wind flow at spring and summer seasons. The electrical conductivity of irrigation water was considered about 1.1 dS.m-1, in basic designs of this irrigation method. In addition to sugarcane ...
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Introduction: Sugarcane fields of the southwest of Iran have heavy soil texture, high temperatures, hot and dry wind flow at spring and summer seasons. The electrical conductivity of irrigation water was considered about 1.1 dS.m-1, in basic designs of this irrigation method. In addition to sugarcane production, sugar is a fundamental good in the economic section of Iran. It has multiple use in food, medical and chemical industry, production of by-products such as feedstuffs, yeast and alcohol, wood and paper. Sugarcane requires lots of water during the growing period and sensitive to water stress and is not compatible with long duration of flooding. If groundwater rises and covers the root zone, crop yield decreases due to root rot. Significant benefits are identified in terms of increased yield, improved crop quality, reduction in applied water, and reduced agronomic costs for weed control, fertilization, and tillage. Improved water management is crucial for a sustainable future, and SDI will be one tool that is available to improve water productivity. The main advantages of SDI are related to water savings because water is applied directly to the crop’s root zone, which prevents losses due to direct evaporation from the soil and deep drainage, and, if properly managed, SDI allows for the maintenance of appropriate levels of soil moisture. Due to the water crisis in Iran, this study aimed to reduce the volume of consumed water and water productivity for sugarcane and sugar yield by managing water consumption using drip irrigation for the first time in the cultivation of sugarcane. Material and Methods: According to recent droughts and severe water crises in Iran, subsurface drip irrigation was implemented in sugarcane for the first time. It seems that water consumed in subsurface drip irrigation is less than other methods. Therefore, its effect was investigated by 15, 20, and 30 cm depths and 75 cm space of subsurface emitters and comparison with control, on water productivity and sugarcane yield. An experiment based on randomized complete block design was carried out at the Sugarcane Research and Training Institute of Khuzestan in the South-West of Iran. After harvesting the plant field (start Ratoon), soil samples were collected at 0-30, 30-60, and 60-90 cm depths. In order to measure the bulk density of soil, samples were collected from the undistributed samples with sampler cylinders, and the texture was determined by the hydrometer method. To assess soil moisture percentage, pressure plate was used for determining content in field capacity (FC) and permanent wilting point (PWP) (the results were 25.1% and 12.9%, respectively). Emitters were pressure controlled emitter type, anti-siphon and the pressure at the pump station was 4.3 bar, and emitters with a flow 2.2 liter-1 and the depth of emitters pipes were 15, 20, and 30 cm from the surface soil. Depending on irrigation frequencies and irrigation water acidity, acid was injected into the irrigation water to prevent clogging of the emitters. After a specified time, it was discharged from the network. Regarding the presence of algae in irrigation water, chlorine gas was used in acid filtration before irrigation in field capacity. Finally, the average quantity and quality functions and Water Productivity in subsurface drip irrigation were compared with compression irrigation. For data fitting and curves, EXCEL software was used, and SAS statistical software was used for statistical analysis. Also, to investigate the salinity distribution in drip irrigation, the mean soil samples were used during the sampling period. The figures were drawn using 8 Surfer software in two dimensions. In drawing the shapes, Craig’s introspection was used. Results and Discussion: High evaporation, air temperature, and relatively low quality of irrigation water are the most important limiting factors for sugarcane irrigation in Khuzestan. It seems that according to the research records, the irrigation of subsurface drops with proper management is successful. Therefore, for this purpose, the effect of planting depth of 15, 20, and 30 and a distance of 75 cm drops and to compare with the regular irrigation of sugarcane lands as control (control), on water productivity and sugarcane yield complete random blocks was applied. The results of the analysis of variance of quantitative traits showed significant effects of the planting depth of droplets, in terms of yield at the level of one percent and in terms of stem height traits, number of stems per hectare, and water efficiency per sugarcane and produced sugar, at the level of five percent. According to the results of qualitative traits, the effect of treatment of droplet implant depth in all traits was non-significant. At a depth of 20 cm, the highest efficiency of water production for sugarcane and sugar production were 1.6 and 0.73 kg / m3, respectively. The lowest water productivity for sugarcane and sugar produced in the control treatment was 4.2 and 0.51 kg / m3, respectively. As a result, water productivity in the treatment of selected index (planting depth of 20 cm) per sugarcane and produced sugar has resulted in an increase of more than 30% in water productivity compared to the usual irrigation of fields (control). The results of salinity distribution around the droplets also showed that under the conditions of irrigation of subsurface droplets with salt water, the lowest salinity values were always seen as a range around the droplets. With increasing distance from the droplets, the salinity increased. More salts The drops are concentrated in the streams on both sides of the drops, The highest salinity occurred at the bottom of the furrow, and the lowest salinity was found on the ridge, where the drip pipe was planted and on either side of which there were two rows of reeds. Conclusion: Subsurface drip irrigation is one of the most optimal irrigation methods that are almost unknown to sugarcane in the executive, research, and academic sectors, and has been implemented for the first time in sugarcane cultivation in Iran. Given the recent droughts and the crisis and water scarcity, and the importance of environmental issues, it will be invaluable to investigate further and apply them. In general, in this study, using a flow rate of 2.2 lit/hr and a space of 75 cm and an installation depth of 20 cm droplets, the highest quantitative and qualitative functions and the highest water productivity per sugar cane. And the sugar produced. Also, regardless of any deepening treatment, the drip irrigation system, compared to the conventional irrigation system, reduced water consumption by about 20% and water yield by 26% per sugarcane and sugar produced. According to the results and considering the uniformity of moisture distribution, soil surface salinity, lack of runoff, protection of the discharge pipe, removal of surface evaporation and sugarcane root development, depth of 20 cm, application of the discharge pipe with a distance of 75 cm drops on the hose with a flow rate of 2.2 lit/hr are recommended. Also, although the distribution of moisture onions is provided up to a distance of 80 cm, a shorter distance between the droplets, such as 60 cm with the above flow, needs further investigation.
Iman Nikravesh; Saeid Boroomand Nasab; AbdAli Naseri; Amir Soltani Mohamadi
Abstract
Introduction: Organic matter is considered as the main element for soil fertility by improving the condition of agglomeration, porosity and soil permeability. One of the most useful ways to use plant debris is to turn it into Biochar and Hydrochar. Biochar is a kind of coal produced from plant biomass ...
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Introduction: Organic matter is considered as the main element for soil fertility by improving the condition of agglomeration, porosity and soil permeability. One of the most useful ways to use plant debris is to turn it into Biochar and Hydrochar. Biochar is a kind of coal produced from plant biomass and agricultural waste that is burned in the presence of low oxygen content or its absence. The hydrothermal process involves heating the biomass or other materials in a pressurized in the presence of water at a temperature between 180 and 250 C, and the result of this reaction is coal (Hydrochar) and soluble organic matter. Biochar and Hydrochar have several advantages such as climate change mitigation through carbon sequestration, soil cation exchange capacity (CEC) increasing, soil fertility, plant growth and root development, improved soil structure and stability, increased soil moisture storage capacity and soil pH adjustment. Coarse soils have large pores and they have low ability to absorb the water and nutrient. The aim of this research was to determine the optimum temperature of wheat straw Biochar and Hydrochar production, and to investigate the effect of these materials on bulk density, total porosity and moisture curve of Sandy Loam soil.
Materials and Methods: In order to produce biochar, at first the wheat straw was washed and dried in the oven. Then it was grinded and was made at different temperatures (200 to 600 ̊ C) inside a furnace for four hours. Similar to biochar, for producing hydrochar, after washing and drying the wheat straw it was grinded into particles ranges from 0.5 to 1 mm. Then it was placed in a stainless steel autoclave with deionized water. The autoclave was heated at different temperatures between 140-230 ̊ C for four hours. The optimum temperature for producing of biochar and hydro-char was determined by using stable organic matter yield index (SOMYI), and it was used in this study. The pH and EC of the biochar and hydro-char samples were measured by combining 1 g of a sample with 20 mL DI water. The cationic and anionic exchange capacity were determined by replacing sodium nitrate with hydrochloric and potassium chloride (Chintala et al., 2013). Surface area was obtained using methylene blue method. A CHNSO Elemental Analyzer (Vario ELIII- elementar- made in Germany) was used to determine the content of C, N, H, S and O in the samples. Potassium and sodium content were measured by flame photometer and calcium and magnesium were measured by titration with EDTA. Biohchar and hydrochar treatments were applied at three levels of 2, 5 and 10 mg / kg soil in three replications in 21 lysimeter. The bulk density, total porosity and moisture curve of soil were measured after four-month irrigation period.
Results and Discussion: According to the calculated value of stable organic matter yield index (SOMYI) at various temperatures in this study, the maximum thermal constancy of wheat straw biochar was 16.20 at temperature of 300 ̊ C and for hydro-char was obtained as 6.13 at the temperature of 200 ̊ C. So, the temperatures of 300 and 200 ̊C were determined as the optimum temperature of sustainable carbon biochar and hydro-char production and were used to continue the experiments of this study. The results showed that addition of HW2, HW5, HW10, BW2, BW5 and BW10 to soil compared to control treatment significantly decreased the bulk density of the soil, 8.97, 11.77, 15.17, 7.9, 10 and 13.10 percent respectively. Also, results showed that addition of HW2, HW5, HW10, BW2, BW5 and BW10 to the soil as compared to control treatment increased soil porosity by 8.8, 11.48, 15.77, 6.48, 9 and 22.13 percent, respectively. The reason for reducing the soil bulk density and increasing the total porosity of soil can be due to the mixing of the soil with materials with a lower bulk density and the effect of increasing the organic matter of the soil due to the use of Biochar and Hydrochar. Based on statistical analysis, wheat straw Biochar and Hydrochar had a significant effect (P
mostafa yaghoobzadeh; Saeid Boroomand Nasab; Zahra Izadpanah; Hesam Seyyed Kaboli
Abstract
Introduction: Accurate estimation of evapotranspiration plays an important role in quantification of water balance at awatershed, plain and regional scale. Moreover, it is important in terms ofmanaging water resources such as water allocation, irrigation management, and evaluating the effects of changing ...
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Introduction: Accurate estimation of evapotranspiration plays an important role in quantification of water balance at awatershed, plain and regional scale. Moreover, it is important in terms ofmanaging water resources such as water allocation, irrigation management, and evaluating the effects of changing land use on water yields. Different methods are available for ET estimation including Bowen ratio energy balance systems, eddy correlation systems, weighing lysimeters.Water balance techniques offer powerful alternatives for measuring ET and other surface energy fluxes. In spite of the elegance, high accuracy and theoretical attractions of these techniques for measuring ET, their practical use over large areas might be limited. They can be very expensive for practical applications at regional scales under heterogeneous terrains composed of different agro-ecosystems. To overcome aforementioned limitations by use of satellite measurements are appropriate approach. The feasibility of using remotely sensed crop parameters in combination of agro-hydrological models has been investigated in recent studies. The aim of the present study was to determine evapotranspiration by two methods, remote sensing and soil, water, atmosphere, and plant (SWAP) model for wheat fields located in Neishabour plain. The output of SWAP has been validated by means of soil water content measurements. Furthermore, the actual evapotranspiration estimated by SWAP has been considered as the “reference” in the comparison between SEBAL energy balance models.
Materials and Methods: Surface Energy Balance Algorithm for Land (SEBAL) was used to estimate actual ET fluxes from Modis satellite images. SEBAL is a one-layer energy balance model that estimates latent heat flux and other energy balance components without information on soil, crop, and management practices. The near surface energy balance equation can be approximated as: Rn = G + H + λET
Where Rn: net radiation (Wm2); G: soil heat flux (Wm2); H: sensible heat flux (Wm2); and λET: latent heat flux (Wm2). Simulations were carried out by SWAP model for two different sites in Faroub and Soleimani fields. The SWAP is a physically based one-dimensional model which simulates vertical transport of water flow, solute transport, heat flow and crop growth at the field scale level. The period of simulation covered the whole wheat growing season (from 1st of December2008 to 30th of July2009. 16 MODIS images was used to determine evapotranspiration during wheat growing season. Inverse modeling of evapotranspiration (ET) fluxes was followed to calibrate the soil hydraulic. While SWAP model has the advantage of producing the right amount of irrigation and evapotranspiration at high temporal resolution, SEBAL can estimate crop variables like leaf area index, NDVI index, net radiation, Soil heat flux, Sensible heat flux and evapotranspiration athigh spatial resolution.
Results and Discussion: Actual and potential evapotranspiration were estimated for SWAP Model during the whole wheat growing season around669.5 and 1259.6 mm for Farub field and 583.7 and 1331.2 mm for Soleimani field, respectively. In contrast with NDVI and net radiation,spatial distribution of SEBAL parameters indicated that soil heat flux, sensible heat flux, and surface temperature of land have the same behavior. At the planting date, evapotranspiration was low and about 1 mm/day, but at the peak of plant growth, it was about 9 mm/day. Moreover, evapotranspiration declined at late growing season to about 3 mm/ day. SWAP model has been calibrated and validated with meteorological data and the data of field measurements of soil moisture. The amount of RMSE of 0.635 and 0.674 (mm/day) and MAE of 0.15 and 0.53 (mm/day) and also coefficient of determination (R2) of 0.915 and 0.964 obtained from comparison of SEBAL algorithm with SWAP model for Farub and Soleimani fields showed that no significant differences was seen between results of two models.
Conclusion: The present study supports the use of SEBAL as the most promising algorithm that requires minimum input data of ground based variables. Results of comparison of SEBAL and SWAP model showed that SEBAL can be a viable tool for generating evapotranspiration maps to assess and quantify spatiotemporal distribution of ET at large scales. Also, it feels that SEBAL and SWAP models can be applied in a wide variety of irrigation conditions without the need for extensive field surveys. This helps significantly in identifying performance indicators and water accounting procedures in irrigated agriculture, and to obtain their likely ranges.
bijan haghighati; saeed Broomand Nasab; AbdAli Naseri
Abstract
Introduction: Potato is one of the main products of agriculture in feeding the world's population and agricultural economy. The production of potato in the world occupies the forth place after wheat, rice and corn. In Iran, annual production of more than 5.5 million tons potato, has made this crop the ...
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Introduction: Potato is one of the main products of agriculture in feeding the world's population and agricultural economy. The production of potato in the world occupies the forth place after wheat, rice and corn. In Iran, annual production of more than 5.5 million tons potato, has made this crop the most important food after wheat. On the other hand, in arid and semi-arid regions, water is the most important limiting factor for production of agricultural crops such as potato. Considering the water use efficiency is one of the most effective ways to deal with the water crisis and increasing the quality and quantity of agricultural productions. Production increasing per unit of water consumed (increasing water productivity) by improving the selection of plant varieties, irrigation management and use of new irrigation methods may be feasible.
Material and Methods: The research was performed in the Chahartakhteh research station (32° 18' N. and 50° 55' E.) with 2090 m height above sea level and semi-humid climate with moderate summers and cold winters. Average annual rainfall is about 320 mm mostly during winter. The soil moisture and temperature regimes are Typic Xeric and Mesic, respectively. Soil texture is silty clay.
In order to determine the best method of deficit irrigation for optimizing water use efficiency and yield of two potato cultivars, an experiment was performed in Agricultural and Natural Resources Research Center of Chaharmahal va Bakhtiari farm in 2013. The experiment was based on randomized completely blocks with split - split plot design in three replications. The furrow and tape drip irrigation methods were as the main plots, two potato cultivars as sub plot units and four deficit irrigation managements as the secondary sub plot units including CI(100%), RDI80(80%), RDI65(65%) of available water depletion (AWD) and partial root-zone drying (PRD) during full growth period.
Almera and Burren cultivars are two new cultivars of high yield and quality of early growth period of approximately 90-80 days, high compatibility with Chaharmahal va Bakhtiari climate and more regions of Iran.
Results and Discussion: Analysis of variance (ANOVA) of studied factors showed that the deficit irrigation management on tuber yield (ton/ha), tuber yield per plant, the amount of starch, soluble sugar, proline, chlorophyll, water use efficiency, and water productivity were significant (P≤0.01). Effects of cultivar on tuber total yield, tuber yield per plant, soluble sugar, water use efficiency, and water productivity were significant (P≤0.01). The interaction between cultivar and deficit irrigation management was only significant (P≤0.05) on tuber yield (ton/ha), proline, water use efficiency and water productivity.
The results showed that Burren cultivar in comparison with Almera was better in tuber yield (19%), water productivity (20%), water use efficiency (19%), and resistance of draught in all deficit irrigation treatments. Maximum tuber yield (59.02 ton/ha) was obtained in Burren cultivar under complete irrigation. Minimum tuber yield (23.1 ton/ha) was obtained in Almera cultivar under deficit irrigation management RDI65 (65% of available water depletion). The maximum water use efficiency (16.79 Kg/m3) and water productivity (14.78 Kg/m3) were obtained under tape irrigation and partial root-zone drying (PRD) treatment. The minimum water use efficiency (7.46 Kg/m3) and water productivity (4.81 Kg/m3) were obtained under furrow irrigation and deficit irrigation management RDI65.
Effect of cultivar was not significant on amount of irrigation water during the growing season. The amount of irrigation water for two cultivars was the same and 4711 m3.ha-1. The amount of irrigation water in the different deficit irrigation managements showed that the highest water use was in CI (5615 m3 ha-1) and lowest water use was in deficit irrigation management RDI65 (4065 m3 ha-1) treatments.
Deficit irrigation management RDI80 ،PRD and RDI65 in comparison with CI led to reduction of irrigation water amount 16, 21 and 28% of irrigation water amount.
Conclusion: Due to the results of this study, the high consumption of water in agriculture, for optimal use of available water resources, the methods with high water use efficiency and productivity, such as tape irrigation, the PRD irrigation management and the use of drought resistant cultivars is recommended. According to the limitation of water resources, for optimizing water use, the best suggestion for reducing water use on potato, is using Burren cultivar with suitable quality and high yield potential, and deficit irrigation management (PRD).
M. Delghandi; S. Broomandnasab; B. Andarzian; A.R. Massah-Bovani
Abstract
Introduction In recent years human activities induced increases in atmospheric carbon dioxide (CO2). Increases in [CO2] caused global warming and Climate change. Climate change is anticipated to cause negative and adverse impacts on agricultural systems throughout the world. Higher temperatures are expected ...
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Introduction In recent years human activities induced increases in atmospheric carbon dioxide (CO2). Increases in [CO2] caused global warming and Climate change. Climate change is anticipated to cause negative and adverse impacts on agricultural systems throughout the world. Higher temperatures are expected to lead to a host of problems. On the other hand, increasing of [CO2] anticipated causing positive impacts on crop yield. Considering the socio-economic importance of agriculture for food security, it is essential to undertake assessments of how future climate change could affect crop yields, so as to provide necessary information to implement appropriate adaptation strategies. In this perspective, the aim of this study was to assess potential climate change impacts and on production for one of the most important varieties of wheat (chamran) in Khouzestan plain and provide directions for possible adaptation strategies.
Materials and Methods: For this study, The Ahvaz region located in the Khuzestan province of Iran was selected.
Ahvaz has a desert climate with long, very hot summers and mild, short winters. At first, thirteen GCM models and two greenhouse gases emission (GHG) scenarios (A2 and B1) was selected for determination of climate change scenarios. ∆P and ∆T parameters at monthly scale were calculated for each GCM model under each GHG emissions scenario by following equation:
Where ∆P, ∆T are long term (thirty years) precipitation and temperature differences between baseline and future period, respectively. average future GCM temperature (2015-2044) for each month, , average baseline period GCM temperature (1971-2000) for each month, , average future GCM precipitation for each month, , average baseline period GCM temperature (1971-2000) for each month and i is index of month. Using calculated ∆Ps for each month via AOGCM models and Beta distribution, Cumulative probability distribution function (CDF) determined for generated ∆Ps. ∆P was derived for risk level 0.10 from CDF. Using the measured precipitation for the 30 years baseline period (1971-2000) and LARS-WG model, daily precipitation time series under risk level 0.10 were generated for future periods (2015-2045 and 2070-2100). Mentioned process in above was performed for temperature. Afterwards, wheat growth was simulated during future and baseline periods using DSSAT, CERES-Wheat model. DSSAT, CERES4.5 is a model based on the crop growth module in which crop growth and development are controlled by phenological development processes. The DSSAT model contains the soil water, soil dynamic, soil temperature, soil nitrogen and carbon, individual plant growth module and crop management module (including planting, harvesting, irrigation, fertilizer and residue modules). This model is not only used to simulate the crop yield, but also to explore the effects of climate change on agricultural productivity and irrigated water. For model validation, field data from different years of observations were used in this study. Experimental data for the simulation were collected at the experimental farm of the Khuzestan Agriculture and Natural Resources Research Center (KANRC), located at Ahwaz in south western Iran.
Results and Discussion: Results showed that wheat growth season was shortened under climate change, especially during 2070-2100 periods. Daily evapotranspiration increased and cumulative evapotranspiration decreased due to increasing daily temperatures and shortening of growth season, respectively. Comparing the wheat yield under climate change with base period based on the considered risk value (0.10) showed that wheat yield in 2015-2045 and 2070-2100 was decreased about 4 and 15 percent, respectively. Four adaptation strategies were assessed (shifting in the planting date, changing the amount of nitrogenous fertilizer, irrigation regime and breeding strategies) in response to climate change. Results indicated that Nov, 21 and Dec, 11 are the best planting dates for 2015-2045 and 2070-2100, respectively. The late season varieties with heat-tolerant characteristic had higher yield in comparison with short and normal season varieties. It indicated that breeding strategy was an appropriate adaptation under climate change. It was also found that the amount of nitrogen application will be reduced by 20 percent in future periods. The increase and decease of one irrigation application (40mm) to irrigation regime of base period resulted in maximum yield for 2015-2045 and 2070-2100, respectively. But, reduction of two irrigation application (80mm) resulted in maximum water productivity (WPI).
Conclusions In the present study, four adaptation strategies of wheat (shifting in the planting date, changing the amount of nitrogenous fertilizer, irrigation regime and breeding strategies) under climate change in Ahvaz region were investigated. Result showed that Nov, 21 and Dec, 11 were the best planting dates for 2015-2045 and 2070-2100, respectively. The late season varieties with heat-tolerant characteristic had higher yield in comparison with short and normal season varieties. It indicated that breeding strategy was an appropriate adaptation strategy under climate change. It was also found that the amount of nitrogen application will be reduced by 20 percent in future periods. The increase and decease of one irrigation application (40mm) to irrigation regime of base period resulted in maximum yield for 2015-2045 and 2070-2100, respectively.
M. Ghahremannejad; Saeid Boroomand Nasab; AbdAli Naseri; A. Sheini Dashtegol
Abstract
Introduction: Infiltration is the most important physical properties of agricultural soils. Infiltration families are general relationships that attempt to categorize the infiltration behavior of soils. Walker et al. (2006) discussed the assumptions and procedures used to develop the original NRCS families. ...
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Introduction: Infiltration is the most important physical properties of agricultural soils. Infiltration families are general relationships that attempt to categorize the infiltration behavior of soils. Walker et al. (2006) discussed the assumptions and procedures used to develop the original NRCS families. Those families categorize infiltration behavior according to their steady-intake rate and were developed largely from border irrigation data. As such, those families have been more widely adopted in border/basin irrigation analyses than in furrow studies. In 2004, NRCS decided to revise the families, largely with the goal of enhancing their applicability to furrow irrigation (Walker et al., 2006). In contrast with the original families, Walker et al. (2006) categorized infiltration based on the average rate during the first 6 h of opportunity time. The new families were developed from furrow infiltration measurements, and then adapted to border conditions. Those infiltration measurements were obtained under inflow rate, slope, cross section, and roughness conditions. Recognizing that these flow conditions affect flow depth and that flow depth affects infiltration in furrows, Walker et al. (2006) proposed procedures for adapting the parameters to new hydraulic conditions. Procedures are also provided for adapting the parameters to events late in the irrigation season. Another important aspect of the new families is the use of the Extended Kostiakov equation, which represents steady-state infiltration better than the Kostiakov formula employed by the original NRCS families. The procedures used to adapt the furrow infiltration parameters to different hydraulic conditions are empirical. From the available data, Walker et al. (2006) developed relationships for the reference parameter values (Kref, aref, and f0ref) and reference hydraulic conditions (discharge Qref and wetted perimeter1 WPref) as a function of Fn, the family value.
In this study the currency of revised SCS method to estimate infiltration parameters of furrow irrigation systems in Amirkabir sugar cane fields was evaluated. For this purpose, infiltration parameters and the cumulative 6 hours infiltration (z) for furrow irrigation systems of this region was estimated with revised SCS method and, then compared with field measurement of z. Then, general functions were developed to adjust the parameters to later flow irrigation conditions.
Materials and Methods: This research was carried out from January 2010 to December 2011. As one of the research fields of Sugarcane Research Center in Amir Kabir Sugarcane Planting and by Products Company of Khuzestan. The field work was conducted on one set of furrow irrigation. This set had three furrows1.8 m wide and 140 m long. The middle furrow of each set was used to take measurements, while the side furrows were used as buffering area. The intake family numbers in revised SCS method (Fn) based on the average infiltration rate during the first 6 h of irrigation. To determine the Fn, double ring experiment were performed before irrigation. Then revised SCS parameters and original SCS parameters were determined. By measuring inflow, outflow, and calculating surface water storage, the volume of infiltrated water was determined. The advance and recession times were recorded at 14 points at 10 m intervals along each furrow. Seven irrigation events were examined. Fiberglass flumes (WSC) type II was used at the beginning and the end of each furrow in the first set where inflow/outflow measurements were to be taken. Experiments were carried out in order to determine the final infiltration rate (f0) with the assumption of uniform soil infiltration characteristics. First, inflow and outflow of the furrow were measured at the beginning and the end of two Fiberglass WSC flumes. Then, when the flow reached a constant level, f0 was measured.
Results and Discussion: For evaluation of the results, four statistical indices: average prediction error of model (Er), distribution into 45° line (λ), determination coefficient (R2) and average relative error of model (Ea) were used. According to the results, revised SCS method overestimated infiltration value and it had an excessive error. Due to the high error of this technique, empirical formulas for reference parameters to this irrigation conditions was determined. The values of a, K, and F0 parameters were measured in field and correlated with the NRCS Family Number, Fn. Then, general functions were developed to adjust the parameters to later flow irrigation conditions. Review the accuracy of the presented functions showed that these functions with values of λ, R2 and Ea respectively 0.95, 0.91 and %4.5, has the best prediction of infiltration. The coefficient of irrigation condition factor (ICF) for the desired area was determined that the average numeric value equal to 0.82. According to the results of Walker et al. (2006), a typical later continuous intake can be estimated by ICF of 0.80. The average value of the 6 h intake rate (Fn) for the desired area is 0.46 and the average value of basic infiltration rate (f0) is 0.48 which is larger than Fn. This is consistent with the results of Walker et al. (2006).
Conclusion: Results of this study showed that the original SCS method has underestimated cumulative infiltration and revised SCS method with furrow irrigation equations has the overestimated cumulative infiltration. General functions were developed to adjust the parameters to later flow irrigation conditions. Review the accuracy of the presented functions showed that these functions have the best prediction of infiltration. The coefficient of irrigation condition factor (ICF) was also determined, (ICF= 0.82).
R. Lalehzari; Saeid Boroomand Nasab; Hadi Moazed; A. Haghighi
Abstract
Introduction: Groundwater is the largest resource of water supplement and shortages of surface water supplies in drought conditions that requires an increase in groundwater discharge. Groundwater flow dependson the subsurface properties such as hydraulic gradient (water table gradient or head loss in ...
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Introduction: Groundwater is the largest resource of water supplement and shortages of surface water supplies in drought conditions that requires an increase in groundwater discharge. Groundwater flow dependson the subsurface properties such as hydraulic gradient (water table gradient or head loss in artesian condition) and hydrodynamic coefficients. The flow treatment is analyzed with an accurate estimation of effective parameters in groundwater equation. This function is obtained using the continuous equation. Inlet and outlet flows of a cell are equal to storage amounts in the continuous equation. Analytical solution of this equation is complex, so numerical methods are developed including finite element and finite difference methods. For example, Feflow is a groundwater modeling tool that makesuse of finite element method (Reynolds and Marimuthu, 2007). Modflow as a finite difference three-dimensional model simulated underground flow under steady and unsteady conditions in anisotropic and non-homogeneous porous media. Modflow is designed to simulate aquifer systems in which saturated-flow conditions exist, Darcy’s Law applies, the density of groundwater is constant, and the principal directions of horizontal hydraulic conductivity or transmissivity do not vary within the system. In Modflow, an aquifer system is replaced by a discretized domain consisting of an array of nodes and the associated finite difference blocks. Groundwater modeling and water table prediction by this model have the acceptable results, because many different informations of water resource system are applied. Many people and organizations have contributed to the development of an effective groundwater monitoring system, as well as experimental and modeling studies (Lalehzari et al., 2013). The objective of this paper is investigation of hydraulic and physical conditions. So, a numerical model has to be developed by PMWIN software for Bagh-i Malek aquifer to calculate hydrodynamic coefficients and predict water table in the future.
Materials and Methods: Bagh-i Malek aquifer located in Khuzestan province is mainly recharged by inflow at the boundaries, precipitation, local rivers and return flows from domestic, industrial and agricultural sectors. The discharge from the aquifer is through water extraction from wells, springs, and qanats as well as groundwater outflow and evapotranspiration. In this study, conceptual model of Bagh-i Malek aquifer on the framework of finite difference numerical approach has been used in simulating groundwater flow treatment. Water table data of 8 piezometers was collected for the 10 year duration from 2002 to 2012. The study years are divided into 40 seasonal stress periods with daily time step. Hydraulic conductivity, specific yield and recharge were calibrated in these periods. Verification was made between the simulated and measured hydraulic heads in the next calibration year. To simulate the groundwater table elevation in this study area, the PMWIN model is used. Bagh-i Malek aquifer is considered as a single layered aquifer, and therefore only the horizontal hydraulic conductivity is estimated. Modflow was used to simulate both steady state and transient flow systems. In steady conditions it is assumed that the total of time simulation is a time period and it does not change inlet data in the modeling duration. In unsteady conditions,the duration of study is divided into some stress periods that data is changed in every period.
Results and Discussion: Estimation of hydraulic conductivity is the first step of calibration process at steady state conditions. The correct assignment of hydraulic conductivity has a main effect on other parameters accuracy. Hydraulic conductivity mapping indicated that the maximum values are in the Eastern North (6-7 m/day) of the aquifer. The twice calibrated parameter is specific yield in unsteady conditions. Specific yield mapping indicated that the values vary from 0.03 to 0.08 and are maximum in the Southern regions of the plain similar to hydraulic conductivity. The results confirm that the flow model has the tolerable simulation accuracy by variances of 3.1 and 3.84 in calibration and verification processes, respectively. The sensitivity of the flow model to decreasing the hydraulic conductivity is more than increasing it. 50 percentage declined into the hydraulic conductivity causes the increase of the variance from 3.1 of initial value to 44.
Conclusions: Mapping of calibrated hydraulic conductivity showed that the Eastern North of aquifer has the higher transmissivity and discharge capability in comparison to Southern parts. At last, the result show that the Bagh-i Malek aquifer model is sensitive to recharge, hydraulic conductivity and specific yield, respectively.
M. Tabei; Saeid Boroomand Nasab; A. Soltani Mohamadi; A. H. Nasrollahi
Abstract
Introduction: The to be limited available water amount from one side and to be increased needs of world population from the other side have caused increase of cultivation for products. For this reason, employing new irrigation ways and using new water resources like using the uncommon water (salty water, ...
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Introduction: The to be limited available water amount from one side and to be increased needs of world population from the other side have caused increase of cultivation for products. For this reason, employing new irrigation ways and using new water resources like using the uncommon water (salty water, water drainage) are two main strategies for regulating water shortage conditions. On the other side, accumulation of salts on the soil surface in dry regions having low rainfall and much evaporation, i.e. an avoidable case. As doing experiment for determining moisture distribution form demands needs a lot of time and conducting desert experiments are costly, stimulator models are suitable alternatives in answering the problem concerning moving and saltiness distribution.
Materials and Methods: In this research, simulation of soil saltiness under drip irrigation was done by the SWAP model and potency of the above model was done in comparison with evaluated relevant results. SWAP model was performed based on measured data in a corn field equipped with drip irrigation system in the farming year 1391-92 in the number one research field in the engineering faculty of water science, ShahidChamran university of Ahvaz and hydraulic parameters of soil obtained from RETC . Statistical model in the form of a random full base plan with four attendants for irrigating water saltiness including salinity S1 (Karoon River water with salinity 3 ds/m as a control treatment), S2 (S1 +0/5), S3 (S1 +1) and S4 (S1 +1/5) dS/m, in 3 repetition and in 3 intervals of 10 cm emitter, 20 cm emitters on the stack, at a depth of 0-90 cm (instead of each 30 cm) from soil surface and intervals of 30, 60 and 90 days after modeling cultiviation was done. The cultivation way was done handheld in plots including four rows of 3 m in distance of 75 cm rows and with denseness of 80 bushes in a hectar. Drip irrigation system was of type strip with space of 20 cm pores.
Results and Discussion: The results of this section of work have shown in the form of chart drawing and calculating identity indices or recognition (R2), maximum error (ME), normalized root mean second error (NRMSE) and coefficient of residual mass (CRM) in the distances on the stack, 10 and 20 cm dropper. The amount of R2, ME, NRMSE and CRM in 10 cm dripper were calculated to be 0/81, 0/46, 11/77 and 0/018 mg/cm3, in 20 cmdripper 0/78, 0/48, 16/44 and 0/1172 mg/cm3 and on the stack 0/75, 2/8, 18/19 and 0/07 mg/cm3. The highest recognition factor was a distance of 10 cm dripper (81 percent) and then reduces to keep distance from dripper recognition factor . This subject is the highest potency close to the dripper. This can happen for less saltiness in the spaces close to the dripper according to drip irrigation features. The high ME amount shows the less attendance computing of the model, it comes to it’s maximum on the stack, however (2/8 mg/cm3), the distances near to the dripper the obtained ME amount shows the good care in estimating soil saltiness. Also, based on being positive CRM parameter amount was seen. It is less in the amount observed in anticipating of saltiness in the anticipated amount. By considering NRMSE factor, higher amount of anticipating is based on observations.
Conclusion: Generally, the results obtained from stimulating of SWAP show that this model can stimulate saltiness distribution in soil under drip irrigation with salty water. This model can be used as useful tools for evaluation of saltiness distribution around the dripper.
Reza Lalehzari; F. Ansari Samani; Saeid Boroomand Nasab
Abstract
Evaluation procedures have been developed for effective design and management of irrigation systems. Furrow irrigation is one of the main types of applying water in agriculture. In the present study, a new procedure for field evaluation of water distribution in furrow irrigation is proposed. For this ...
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Evaluation procedures have been developed for effective design and management of irrigation systems. Furrow irrigation is one of the main types of applying water in agriculture. In the present study, a new procedure for field evaluation of water distribution in furrow irrigation is proposed. For this purpose, application efficiency (Ea), water requirement efficiency (Er), deep percolation (DP) and tail water ratio (TWR) have been introduced based on the average of the non-dimensional infiltrated depth values in the four data groups. The relationships between coefficient of uniformity, CU and distribution uniformity, DU have been described by opportunity time values of each quarter and using the linear equation instead of infiltration function. The proposed method was compared to other procedures by 9 scenarios of field data with different discharges and lengths. The results show that the evaluation indicators of furrow irrigation depend on the hydraulic characteristics of the soil and the opportunity time. Also, there was no observed any significant difference on the suggested indexes values and classical performance indicators.
Mahdi Delghandi; Saeid Boroomand Nasab
Abstract
Field experiments for quantifying optimal breeding strategies are time-consuming and expensive. Crop simulation models can provide an alternative, less time-consuming and inexpensive means of determining the optimum breeding strategies. These models consider the complex interactions between weather, ...
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Field experiments for quantifying optimal breeding strategies are time-consuming and expensive. Crop simulation models can provide an alternative, less time-consuming and inexpensive means of determining the optimum breeding strategies. These models consider the complex interactions between weather, soil properties and management factors. CERES-Wheat is one of best models which can simulate the growth and development of wheat. Therefore, in present paper DSSAT 4.5-CERES-Wheat was evaluated for predicting growth, phenology stages and yield of wheat (cultivar of Chamran) for Ahwaz region. For this purpose, one Experimental research was designed at the experimental farm of the Khuzestan Agriculture And Natural Resources Research Center (KANRC), located at Ahwaz in 2010-2011 growth season. Using results of this research and two another research, CERES-Wheat model was evaluated. Results of evaluation showed that most and less NRMSE were abtained for simulation of maximum Leaf Area Index (6%) and phenology stages (2%), respectively. Therefore, it can conclude that CERES-Wheat is a powerful model in order to simulation of growth, phenology stages and yield of wheat.
I. Nikravesh; Hadi Moazed; S. Broomandnasab; AbdAli Naseri
Abstract
Many of irrigated agriculture problems are resulting from chemical and physical composition of irrigation water. The irrigation water quality is effective on soil moisture characteristic curve by effect on soil structure, pore size distribution and continuity of them. The aim of this study was to evaluate ...
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Many of irrigated agriculture problems are resulting from chemical and physical composition of irrigation water. The irrigation water quality is effective on soil moisture characteristic curve by effect on soil structure, pore size distribution and continuity of them. The aim of this study was to evaluate the effect of different water salinity in the presence of constant turbidity on the soil moisture curve. The salinity treatments at five levels (1, 2, 4, 6 and 8 dS/m) with constant turbidity (200 NTU) were applied. These treatments were investigated at three depths of soil (0 to 15, 15 to 30 and 30 to 45 cm) with a silt-loam texture with three replications in a randomized complete block design. Soil water retention curve was determined by using pressure plate method. The results were statistically analyzed with MSTATC software. The results showed that the water percent of the soil of S2, S3, S4, S5 treatments of irrigation water quality increased to values 13.65, 20.20, 23 and 30 percent compared to S1 treatment. Comparison of water percent of soil at various depths showed that the depth of the second and third compared to the first decreased to 1.40 and 2 percent.
Saeid Boroomand Nasab; Mohammad javad khangani
Abstract
Deficit irrigation is an optimization strategy for water use efficiency in irrigation. This research was conducted to evaluation effect of deficit irrigation (DI) and partial root zone drying (PRD) on yield, yield components and water use efficiency of corn. Research was conducted on Shahid Bahonar University ...
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Deficit irrigation is an optimization strategy for water use efficiency in irrigation. This research was conducted to evaluation effect of deficit irrigation (DI) and partial root zone drying (PRD) on yield, yield components and water use efficiency of corn. Research was conducted on Shahid Bahonar University of Kerman in the spring of 2010 using a completely randomized block design with one control, 18 deficit irrigation treatment and three blocks. Deficit irrigation treatments were included: mild water stress (irrigation with درصد75 ETP), high water stress (irrigation with %50 ETP), fixed every other furrow irrigation and three partial root zone drying (Change the wet furrows in every irrigation, Change the wet furrows in every other irrigation and change the wet furrows in every second irrigations). Every treatment was applied at three growth stages of corn (all periods of growth, vegetative growth stage and reproductive growth stage). The highest biological yield obtained 32431 and the lowest was 17654 kg per hectare. The highest grain yield was 12115 kg per hectare and the lowest was 7163. Water use efficiency (km grain yield per cubic meter of water) for the control treatment was equal to 1.16 and for partial root zone drying with change the wet furrows in every irrigation (14 days) in all periods of growth treatment was equal to 2.13. Results showed that partial root zone drying with one interval irrigation (14-day) was the best choice to apply deficit irrigation on corn.
E. Zangene Usefabadi; M. Behzad; S. Boroomand Nasab
Abstract
In this study, the level of cations and anions of saline soil leaching was investigated in laboratory conditions by using of magnetic water. silty loam Soil was poured in 50 cm height and 10 cm diameter pipes while the end of each pipe was closed with a filter paper and a plastic net. leaching was conducted ...
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In this study, the level of cations and anions of saline soil leaching was investigated in laboratory conditions by using of magnetic water. silty loam Soil was poured in 50 cm height and 10 cm diameter pipes while the end of each pipe was closed with a filter paper and a plastic net. leaching was conducted alternatively after passing water through the magnetic field with different intensities. The drained water was collected from the end of soil columns and analyzed chemically in the laboratory. The final results showed that the amount of the leaching of sodium, potassium, chlorine and sulfate in the magnetic treatment was significantly more than control treatment (α
M. Delghandi; M. Behzad; S. Broomandnasab
Abstract
چکیده
قطره چکان مهمترین قسمت آبیاری قطره ای محسوب می گردد برای طراحی و ساخت قطره چکان های با کارایی بالا، لازم است اطلاعات کاملی از چگونگی مکانیسم جریان درون مجاری آن ...
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چکیده
قطره چکان مهمترین قسمت آبیاری قطره ای محسوب می گردد برای طراحی و ساخت قطره چکان های با کارایی بالا، لازم است اطلاعات کاملی از چگونگی مکانیسم جریان درون مجاری آن ها داشته باشیم، به دلیل ریز و پیچیده بودن هندسه مجاری مارپیچ قطره چکان ها، استفاده از دینامیک سیالات محاسباتی (CFD) برای مطالعه خصوصیات هیدرولیکی جریان درون مجاری آن ها، بسیار مناسب میباشد. در این مطالعه با استفاده از دینامیک سیالات محاسباتی، رفتار جریان داخل قطره چکان ها برای بدست آوردن نحوه توزیع سرعت و فشار به منظور طراحی نرم افزاری قطره چکان ها شبیه سازی شد و رابطه بین فشار و میزان دبی، تحت شش فشار مختلف به دست آمد. بدین منظور سه نمونه از دو نوع قطره چکان تیپ پلاک دار انتخاب، و تخریب شدند. اندازه مجاری با عکس برداری، توسط میکروسکوپ الکترونی (SEM) تعیین شد. سپس جریان درون قطره چکان ها توسط CFD شبیه سازی گردید. و ضرایب معادله دبی- فشار مشخص و توزیع سرعت و فشار داخل مجاری نمایش داده شد. صحت سنجی نتایج حاصله از مدل، براساس ضوابط ارائه شده در استاندارد ISO9261 در آزمایشگاه صورت گرفت. نتایج نشان دادند که داده های به دست آمده از شبیه سازی مطابقت بسیار خوبی با داده های آزمایشگاهی دارد و دینامیک سیالات محاسباتی میتواند ابزار بسیار مناسبی برای کمک به طراحی قطره چکان های با مجاری مارپیچ باشد و با کاهش تعداد قالب های آزمایشی، هزینه تولید قطره چکان ها کاهش مییابد.
واژه های کلیدی: قطره چکان، دینامیک سیالات محاسباتی (CFD)، رابطه دبی – فشار