Research Paper
n s; h p; r a; y m
Abstract
In order to evaluate the possibility and compare different irrigation methods in ricecultivation, an experiment was conducted in factorial based randomized complete blockdesign at Rice Research Institute of Iran, Mazandaran (Amol), during 2011. Treatments weredifferent irrigation regimes including alternate ...
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In order to evaluate the possibility and compare different irrigation methods in ricecultivation, an experiment was conducted in factorial based randomized complete blockdesign at Rice Research Institute of Iran, Mazandaran (Amol), during 2011. Treatments weredifferent irrigation regimes including alternate wet and drying (AWD), semi-dry cultivation(SDC), combining shallow water depth with wetting and drying (SWD) and traditionalirrigation (TI); and two different cultivars, namely, Tarom and Fajr, as local and improvedcultivars, respectively. Results of ANOVA indicated that different cultivars and irrigationmethods were significantly different in terms of irrigation and total water productivity. SDCwith 4042.5 m3ha-1 (nearly 54 percent water saving), irrigation water productivity of WPI=1.68 kg m-3, and total water productivity of WPI+R=1.38 kg m-3 showed better performance ascompared to the other irrigation regimes, especially compared to the traditional management(TI). In conclusion, regarding the better performance in water productivity, advancedirrigation methods (SDC, AWD and SWD, respectively) could be recommended for furtherinvestigations.
Research Paper
m kh; s b; r a
Abstract
The objective of this study was to evaluate the effect of different levels of irrigation and nitrogen fertilizer on nitrate movement, yield, and water use efficiency (WP) of corn in no-till planting method. The research was conducted in two years as a randomized complete block design arranged in a split ...
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The objective of this study was to evaluate the effect of different levels of irrigation and nitrogen fertilizer on nitrate movement, yield, and water use efficiency (WP) of corn in no-till planting method. The research was conducted in two years as a randomized complete block design arranged in a split block treatment design with three replicates in the Safiabad Agricultural Research Center. Irrigation treatments amounts of 50%, 75%, and 100 % of crop water requirement (I1, I2, and I3) were allocated to the main plots, and three levels of nitrogen i.e. 150, 225, and 300 kg ha-1 (N150, N225, and N300) were in the sub plots. The average corn yield of 5 t ha-1 showed that summer corn no-till planting in wheat residue without any tillage practice was applicable in Khuzestan climate conditions. Irrigation treatments had a significant effect on corn yield (p<0.01), such that the maximum yield (5.5 t/ha) was obtained from I3 with 1037 mm applied water, and minimum yield (4.2 t/ha) was from I1 with 786 mm of water. Nitrogen had significant effect on yield (p<0.05) and protein percent (p<0.01), such that the N300 treatment had the maximum yield of 5.4 t/ha with a protein percent of 10.1%. In all treatments, fertilizer was leached within 0-30 cm soil layer, while nitrate concentration in deeper layers was 30-50% of the surface layer. However, in deeper layers, nitrate concentration variation in the same fertilizer treatment was not much.
Research Paper
m.h r; m gh
Abstract
In order to optimize use of water resources with selection of suitable wheat genotype(s) and irrigation schedule, in this experiment, the effect of elimination of irrigation at terminal growth and development stages of five wheat genotypes was investigated in two successive growing seasons (2002-03 and ...
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In order to optimize use of water resources with selection of suitable wheat genotype(s) and irrigation schedule, in this experiment, the effect of elimination of irrigation at terminal growth and development stages of five wheat genotypes was investigated in two successive growing seasons (2002-03 and 2003-04) in the agricultural research station of Torogh Mashhad. Split plot experiments were used based on randomized complete block design with three replications. Irrigation treatments were allocated to the main plots as: W1: irrigation at stem elongation, flowering, milky, and doughy stages; W2: irrigation at stem elongation, flowering, and milky stages; and W3: irrigation at stem elongation and flowering stages. Five wheat genotypes including: C1: Toos, C2: C-78-4, C3: C-78-8, C4: C-79-6, and C5: C-79-16 were assigned to the sub plots. Results showed that the effect of irrigation treatments on biological yield (BY), grain yield (GY), thousands kernel weight (TKW) and water use efficiency (WUE) were significant. Elimination of irrigation in grain filling period i.e. milky and soft dough stages, decreased BY (4.17% and 12.1%, respectively) and GY (5.14% and 11.9%, respectively). The mean GY of bread wheat genotypes under W1, W2, and W3 irrigation treatments were 5834, 5549, and 5215 kg/ha, while WUE values were 1.022, 1.426 and 2.346 kg.m-3, respectively. Although elimination of irrigation in the critical periods of developmental stages (grain filling) of wheat had positive effects on WUE, it had negative effect on GY and, therefore, is not recommended. C4 and C5 genotypes had the highest GY and WUE (1.814 and 1.748 kg.m-3, respectively). However, C4 and C5 genotypes were more tolerant to terminal water stress.
Research Paper
s m; m m; m a
Abstract
Irrigation scheduling means applying the right amount of water at the right time. In this research, thecurrent irrigation scheduling implemented in the Mirza-kuchak-khan Sugarcane Agro-Industry farmslocated in Ahwaz was compared with the actual sugarcane crop water requirement using SWAPmodel. Due to ...
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Irrigation scheduling means applying the right amount of water at the right time. In this research, thecurrent irrigation scheduling implemented in the Mirza-kuchak-khan Sugarcane Agro-Industry farmslocated in Ahwaz was compared with the actual sugarcane crop water requirement using SWAPmodel. Due to lack of field measured data, the SWAP model was calibrated and evaluated usingLANDSAT 7 ETM+ images taken over the study area at twelve different dates during the sugarcanegrowing season. According to the results simulated by the SWAP model, the seasonal irrigation depthapplied (2640 mm) was much more than that required by the crop and, as a result, a significantamount of irrigation water was wasted in the form of deep percolation. The water productivity wasestimated to be 0.35 ton/ha.cm. In order to decrease deep percolation and improve water productivity,six irrigation plans including the possibility to reduce irrigation depth or eliminate some irrigationevents, or change irrigation times were evaluated by the SWAP model. For every plan studied, animproved irrigation scheduling was suggested. According to the SWAP simulations, implementationsof the suggested irrigation scheduling by eliminating some irrigation events or changing irrigationtimes can reduce seasonal irrigation depth by 27% and improve the water productivity by 30%.Reducing irrigation depth by 20% can also increase the water productivity by 26%. In case bothscenarios mentioned can be applied together, the irrigation depth would decrease 42% and waterproductivity would increase 68%.
Research Paper
o z; a m; h b
Abstract
Improving water productivity in food production has been a basic global issue, especially incountries with limited water resources like Iran. Due to quantitative and qualitative limitationsof water, measurement and analysis of agricultural water productivity indicators in Irandeserve special attention. ...
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Improving water productivity in food production has been a basic global issue, especially incountries with limited water resources like Iran. Due to quantitative and qualitative limitationsof water, measurement and analysis of agricultural water productivity indicators in Irandeserve special attention. Accordingly, in the present study, the physical and economicalproductivity of crops in Bahar plain, Hamadan, was investigated for the period of 2010-11. Inthis research, completing previous studies, water productivity indicators in different irrigationmethods were calculated. The results showed that water productivity of the modern irrigationmethods was significantly higher than traditional irrigation methods. Also, based on netbenefit per drop (NBPD) index, garlic and alfalfa, respectively, showed the highest and lowestproductivity. This can be considered as a proposed policy change in cropping pattern.
Research Paper
H T; S M; H Z
Abstract
The present research was conducted to study the effect of irrigation treatments on growth indices, yield, and water use efficiency of long green pepper (Capsicum annuum L.) at the research greenhouse of Shahrekord University. This experiment was done in a clay-loam soil using randomized design with four ...
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The present research was conducted to study the effect of irrigation treatments on growth indices, yield, and water use efficiency of long green pepper (Capsicum annuum L.) at the research greenhouse of Shahrekord University. This experiment was done in a clay-loam soil using randomized design with four treatments i.e. 40%, 60%, 80%, and 100 percent of water requirement and three replications, in 12 pots, during 2012. The obtained results from statistical analysis indicated that the effect of irrigation water on growth indices, yield, and water use efficiency (WUE) was significant at 5% level. Maximum yield and maximum water use efficiency were achieved in treatment of 100 percent water requirement i.e. full irrigation. Furthermore, it was observed that water use reduction by 20%, 40% and 60 percent led to reduction in yield by 26.98%, 50.92% and 69.49 percent, respectively. Moreover, it was observed that water use reduction by 20%, 40% and 60 percent led to reduction in water use efficiency by 10.56%, 22.24% and 29.35% percent, respectively. Since there was no significant difference in yield between 100% and 80 percent treatments, it is recommended that under water shortage conditions, the maximum reduction in water application be limited to 20 percent of water requirement.
Research Paper
SH K; R A; M S
Abstract
With population growing throughout the world, it is necessary to optimize water use,especially in agricultural lands. In order to conduct technical and economical evaluation ofdrip and furrow irrigation methods under deficit irrigation of cotton, a field experiment wascarried out during 2010 growing ...
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With population growing throughout the world, it is necessary to optimize water use,especially in agricultural lands. In order to conduct technical and economical evaluation ofdrip and furrow irrigation methods under deficit irrigation of cotton, a field experiment wascarried out during 2010 growing season at experimental farm of Orzoueyeh Agricultural andNatural Resources Research Center in Kerman province. The treatments were laid out in splitplot a randomized complete block design (RCBD) with three replications. The treatmentscomprised of three levels of irrigation including 100% (control), 80%, and 60 percent of cropwater requirement and were allocated to the main plot and two irrigation systems, consistingof furrow (S1) and surface drip irrigation (S2), were laid in the sub plot. The results showedthat in comparison with furrow irrigation, drip irrigation increased yield, water use efficiency(WUE), number of bolls per plant, and bolls weight by 8%, 44%, 15% and 33%, respectively.Also, compared with 100 percent of crop water requirement, the 80% treatment reduced waterusage by 1900 m3 ha-1, while yield, number of bolls per plant, and bolls weight decreased by1.6%, 9% and 3.6%, respectively, but WUE increased by 18%. Economic efficiency showedthat 80 percent of water requirement in the drip irrigation system was the best treatment.Considering the results obtained in this study and in the light of water saving and higherWUE, as the main objectives in deficit irrigation, for cotton cultivation in Orzoueyeh,application of 80% crop water requirement in the drip irrigation system is preferred.
Research Paper
J B; N A; M M; S B
Abstract
Comparison of Linear and Nonlinear (Bilinear) Time Series Models in Reference Crop Evapotranspiration Prediction in Urmia Synoptic StationReference crop evapotranspiration (ETo) prediction is one of the important elements in optimizing agricultural water consumption. In this regard, one of the prediction ...
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Comparison of Linear and Nonlinear (Bilinear) Time Series Models in Reference Crop Evapotranspiration Prediction in Urmia Synoptic StationReference crop evapotranspiration (ETo) prediction is one of the important elements in optimizing agricultural water consumption. In this regard, one of the prediction approaches is to use the stochastic time series methods. In this research, AR (p) and ARMA(p,q) linear models and Bilinear nonlinear model were compared in predicting the monthly values of ETo in Urmia synoptic station. To conduct the present research, the monthly values of ETo from 1971 to 2010 were calculated and data between 1971-2005 and 2006-2010 were used for models calibration and validation, respectively. In the next step, the suitable linear model was selected and the results of this model and Bilinear nonlinear model were compared with the values of FAO Penman-Monteith method. The results showed that the AR(11) time series model had better results than the other linear models. The comparison of the results of AR(11) model and BL(11,0,1,1) model with the monthly values of the ETo using FAO Penman-Monteith method showed that the value of root mean square error (RMSE) and relative error (VE) in AR(11) model were 1.85 mm and 3.8 %, respectively, and in BL(11,0,1,1) model, they were 1.76 mm and 3.6 %, respectively. Therefore, Bilinear nonlinear model had more capability in modeling and predicting of the monthly values of ETo values in comparing with linear models. In the next step, the monthly values of ETo for five future years were predicted by using the Bilinear nonlinear model.
Research Paper
K A; M SH; F K
Abstract
In order to study the effect of planting arrangements and water quantities in drip irrigation onyield of maize, an experiment was carried out using a spilt block based on randomizedcomplete block design for three years (2006-09) in Moghan. The factorial experiment hadthree planting densities (75000, ...
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In order to study the effect of planting arrangements and water quantities in drip irrigation onyield of maize, an experiment was carried out using a spilt block based on randomizedcomplete block design for three years (2006-09) in Moghan. The factorial experiment hadthree planting densities (75000, 85000 and 95000 plants per hectare ) with one- and two-rowscultivation (B1= one row cultivation with one drip irrigation lateral, B2= two cultivation rowswith one lateral between them) and four levels of irrigation including: I1= 100%, I2= 50%, I3=75%, and I4= 125 percent of evapotranspiration. Traits such as plant height, ear height,number of rows on ear, number of grains on rows, 1000 grains weight and grain yield with14%moisture were measured. The result of combined variance analysis showed significantdifference between irrigation levels at 1% level. Highest grain yield was obtained fromI4,while the lowest yield belonged to I2. On the other hands, the highest and lowest water useefficiency (WUE) belonged to I2 and I4, respectively. There was no significant differenceamong planting densities and cultivation methods. However, density of 75000 plants perhectare and one row cultivation had the highest grain yield among the treatments.
Research Paper
M A; S M
Abstract
Khuzestan province is considered as one of Iran's agricultural hubs, food production andsupply make it necessary to use water and soil resources to the optimum potential.Agricultural drainage waters, with their high volume and decentralized nature, are the mainsource of return flow to the Karun River. ...
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Khuzestan province is considered as one of Iran's agricultural hubs, food production andsupply make it necessary to use water and soil resources to the optimum potential.Agricultural drainage waters, with their high volume and decentralized nature, are the mainsource of return flow to the Karun River. These sources include pesticides and nutrients(nitrate, phosphate) and have high pollution. The purpose of this study was to estimatefarmers’ willingness to pay to reduce water pollution. The study method was surveying withHeckman method and using data from 120 farmers in the Molasany District, in 2012 .Theresults showed that 85 percent of farmers were willing to pay for reducing pollution of theriver. Also, variables such as age, suggested price, family members, and cause of riverpollution had negative and significant effects on people willingness to pay. But, income,education, farmers’ vision, the amount of damage, land ownership, and land size hadsignificant and positive effects. Average of farmers’ willingness to pay for reducing waterpollution was 188,000 Rials ($13 US) per year.