مجله پژوهش آب در کشاورزی
سال بیست و هشتم شماره 1 (بهار 1393)

In order to evaluate the possibility and compare different irrigation methods in rice cultivation, an experiment was conducted in factorial based randomized complete block design at Rice Research Institute of Iran, Mazandaran (Amol), during 2011. Treatments were different irrigation regimes including alternate wet and drying (AWD), semi-dry cultivation (SDC), combining shallow water depth with wetting and drying (SWD) and traditional irrigation (TI); and two different cultivars, namely, Tarom and Fajr, as local and improved cultivars, respectively. Results of ANOVA indicated that different cultivars and irrigation methods were significantly different in terms of irrigation and total water productivity. SDC with 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 as compared to the other irrigation regimes, especially compared to the traditional management (TI). In conclusion, regarding the better performance in water productivity, advanced irrigation methods (SDC, AWD and SWD, respectively) could be recommended for further investigations.

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.

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.

Irrigation scheduling means applying the right amount of water at the right time. In this research, the current irrigation scheduling implemented in the Mirza-kuchak-khan Sugarcane Agro-Industry farms located in Ahwaz was compared with the actual sugarcane crop water requirement using SWAP model. Due to lack of field measured data, the SWAP model was calibrated and evaluated using LANDSAT 7 ETM+ images taken over the study area at twelve different dates during the sugarcane growing season. According to the results simulated by the SWAP model, the seasonal irrigation depth applied (2640 mm) was much more than that required by the crop and, as a result, a significant amount of irrigation water was wasted in the form of deep percolation. The water productivity was estimated 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 irrigation events, or change irrigation times were evaluated by the SWAP model. For every plan studied, an improved irrigation scheduling was suggested. According to the SWAP simulations, implementations of the suggested irrigation scheduling by eliminating some irrigation events or changing irrigation times 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 both scenarios mentioned can be applied together, the irrigation depth would decrease 42% and water productivity would increase 68%.

Improving water productivity in food production has been a basic global issue, especially in countries with limited water resources like Iran. Due to quantitative and qualitative limitations of water, measurement and analysis of agricultural water productivity indicators in Iran deserve special attention. Accordingly, in the present study, the physical and economical productivity of crops in Bahar plain, Hamadan, was investigated for the period of 2010-11. In this research, completing previous studies, water productivity indicators in different irrigation methods were calculated. The results showed that water productivity of the modern irrigation methods was significantly higher than traditional irrigation methods. Also, based on net benefit per drop (NBPD) index, garlic and alfalfa, respectively, showed the highest and lowest productivity. This can be considered as a proposed policy change in cropping pattern.

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.

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 of drip and furrow irrigation methods under deficit irrigation of cotton, a field experiment was carried out during 2010 growing season at experimental farm of Orzoueyeh Agricultural and Natural Resources Research Center in Kerman province. The treatments were laid out in split plot a randomized complete block design (RCBD) with three replications. The treatments comprised of three levels of irrigation including 100% (control), 80%, and 60 percent of crop water requirement and were allocated to the main plot and two irrigation systems, consisting of furrow (S1) and surface drip irrigation (S2), were laid in the sub plot. The results showed that 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 water usage by 1900 m3 ha-1, while yield, number of bolls per plant, and bolls weight decreased by 1.6%, 9% and 3.6%, respectively, but WUE increased by 18%. Economic efficiency showed that 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 higher WUE, 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.

Reference 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.

In order to study the effect of planting arrangements and water quantities in drip irrigation on yield of maize, an experiment was carried out using a spilt block based on randomized complete block design for three years (2006-09) in Moghan. The factorial experiment had three planting densities (75000, 85000 and 95000 plants per hectare) with one- and two-rows cultivation (B1= one row cultivation with one drip irrigation lateral, B2= two cultivation rows with 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 with 14%moisture were measured. The result of combined variance analysis showed significant difference between irrigation levels at 1% level. Highest grain yield was obtained from I4,while the lowest yield belonged to I2. On the other hands, the highest and lowest water use efficiency (WUE) belonged to I2 and I4, respectively. There was no significant difference among planting densities and cultivation methods. However, density of 75000 plants per hectare and one row cultivation had the highest grain yield among the treatments.

Khuzestan province is considered as one of Iran's agricultural hubs, food production and supply 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 main source 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 estimate farmers’ willingness to pay to reduce water pollution. The study method was surveying with Heckman method and using data from 120 farmers in the Molasany District, in 2012. The results showed that 85 percent of farmers were willing to pay for reducing pollution of the river. Also, variables such as age, suggested price, family members, and cause of river pollution had negative and significant effects on people willingness to pay. But, income, education, farmers’ vision, the amount of damage, land ownership, and land size had significant and positive effects. Average of farmers’ willingness to pay for reducing water pollution was 188,000 Rials ($13 US) per year.

Given the importance and limitations of water resources in Iran, use of unconventional water, in areas such as Kerman province, can be considered as conservation of water resources. In order to take advantage of Kerman city wastewater for landscaping and agriculture, for a period of six months, samples were taken from the incoming wastewater and effluent wastewater and TDS, TSS, BOD, COD, pH, alkalinity, total coliform and fecal coliform, nematode eggs, cations, anions, phenol, formaldehyde, detergent and heavy metals were measured. Finally, agriculture irrigation water quality indicators such as EC, SAR and % soluble Na were calculated. The results showed that the mean values on the inlet wastewater, including TSS, BOD, COD were, 490, 207, 379 mg/L and the number of total coliforms and fecal coliform were, respectively, 13.3× 109 and 2.5 ×108 N/100 ml. In the wastewater treatment plant, the above parameters were, respectively, 64.4, 39.8, 74.5 mg/L, and number of total coliform and fecal coliform were, respectively, 100 Ml 48× 105 and 3 ×106. Value of electrical conductivity of the wastewater treatment effluent was 2.86 dS/m and SAR was calculated at7.04. Based on the test results and comparison of the measured parameters in the effluent standards, environmental standards, and guidelines provided by the World Health Organization and FAO, the effluent of wastewater treatment plant in Kerman can be used for growing industrial crops resistant to salinity and medium concentrations of sodium, chloride, bicarbonate, and boron.

In order to investigate the effects of polyethylene and organic mulches in different irrigation intervals on oil content and fatty acids composition in sunflower, an experiment was conducted at the research farm of college of Aboureyhan, University of Tehran, in 2009. The study was conducted in split-plot design based on randomized complete blocks with three replications. The main factor consisted of three irrigation intervals including 7, 12, and 17 days, and the sub-factors were the control (without mulch) and different types of mulch (polyethylene, cow manure including 8.5 ton/ha,17 ton/ha, 25 ton/ha, wheat stubble mulch at three levels of 2.5 ton/ha, 5.5 ton/ha, and 7.5 ton/ha). The results indicated that increasing irrigation intervals and the effect of water deficit stress cause considerable reduction in the amount of oil seed. Also, the highest oil yield was obtained from polyethylene and stubble mulch (7.5 ton/ha). Investigation on fatty acids compositions in sunflower seed indicated that highest fatty acids i.e. palmitic (6.26%) and stearic (4.1%) were obtained under intensive water deficit stress and oleic (40.44%) and linoleic (51.76%) were obtained under mild water deficit stress, respectively. Besides, the highest fatty i.e. acid, palmitic (6.44%) and linoleic (51.17%) were obtained in stubble mulch (7.5 ton/ha) and the highest fatty acid oleic (40.31%) was obtained in cow manure mulch (25 ton/ha). The overall test results showed that mulches can increases the quality and quantity of seed yield by reducing irrigation water use. Considering the results of the study and non-toxic effects of stubble mulches in agriculture, we suggest their usage.

Evapotranspiration is one of the most important factors in basin water balance and water cycle in the nature. Several variables affect evapotranspiration rate. Therefore, all these variables cannot be considered for deriving the equations governing the evapotranspiration process, even if they are available. Determining the most important of these variables, and reducing the number of inputs in modeling process, can lead to increasing the model validity. There are several approaches for sensitivity analysis and identifying the relative influence of different climatic parameters on evapotranspiration. In this study, using computational intelligence techniques and multivariate statistical methods, sensitivity analysis and relative importance of different parameters affecting reference evapotranspiration were investigated in the western and northwestern Iran, based on the FAO Penman-Monteith model. In order to increase the accuracy of the models output results, considering the type of climate in the process of evapotranspiration, using the Ward linkage and Euclidean similarity measure in the cluster analysis technique, based on data from synoptic meteorological stations, the study area was divided into several climatically homogeneous regions. Then, in each of the homogeneous regions, the most important parameters affecting the reference evapotranspiration were identified using three methods of factor analysis, neural networks, and decision tree. Finally, verification and validation of these methods were performed for different homogeneous regions. The results showed that the artificial neural network method had better performance for determining the most important parameters affecting evapotranspiration than decision tree and factor analysis techniques. Finally, using the results of artificial neural network, regional equations were extracted and tested for each homogeneous region.

To investigate the effects of nano iron oxide and urban solid waste compost coated sulfur on physical properties of a saline-sodic soil, a factorial experiment was carried out in a randomized complete blocks design at field scale. The treatments were nano iron oxide powder at two levels (0 and 20 mg/kg) and urban solid waste compost coated sulfur (USWCS) at two levels (0 and 15ton/ha) with three replications. After applying the experimental treatments, sunflower was cultivated. After harvest, the final infiltration rate, mean weight diameter of aggregates (MWD), bulk density (BD), the slope of retention curve at its inflection point (Sgi index), plant available water content (PAWC) and aeration porosity (AC) were determined. Application of USWCS caused significant (p<0.05) increase in all physical properties, except bulk density. Also, application of nano iron oxide increased MWD and Sgi index, significantly (p<0.05). Simultaneous application of USWCS and nano iron oxide resulted in maximum increase in final infiltration rate, Sgi index, and MWD, but decreased BD significantly (p<0.05). According to the results of this research, simultaneous application of nano iron oxide and urban solid waste compost is suggested to increase the availability of nutrients and improve soil physical conditions in saline-sodic soils.

In order to study the most effective traits as well as drought tolerance indices and to introduce tolerant cumin landraces for drought conditions, a field experiment was carried out in 2011 in Kerman, Iran, using split plot design based on randomized complete block with 2 replications Drought stress was applied to nine cumin landraces at flowering stage. Some traits such as plant height, number of sub branch, number of umbels, number of seed per umbels, number of sub-umbels per umbels, thousand-seed weight, grain yield and biological yield were evaluated. The results showed that grain yield, biological yield, thousand-seed weight, plant height and number of umbels diminished under drought stress conditions. The calculated correlation coefficients as well as tolerance indices (TOL, SSI, GMP and STI) showed that Geometric Mean Productivity (GMP) and Stress Tolerance Index (STI) were the best indices for selection of tolerant landraces. Based on these two indices, landraces Pars, Khorasan Razavi, and Yazd are recommended as the tolerant landraces.

In the current study, the water pricing method based on the crop type has been found as the most appropriate method for the case study, Qazvin plain, Iran. To study water pricing, a mathematical model was developed. In the pricing method based on the crop type, three different ways were considered for setting up the average price of water. These three ways consisted of weighting based on the area, volume of water consumption, and price of the crops. Economic efficiency based on current interest rate in the country was compared with reference economic efficiency i.e. when water is free of charge. Meanwhile, regarding the sensitivity analyses of water pricing methods, the economic efficacy was also measured and compared at various situations like increasing cost flows and reducing incomes. After that, the obtained prices were compared in a graph with the water prices that farmers were paying for each of the crops. Among all of the water pricing methods for “Qazvin plain”, the crop-volume of water consumption method had the highest efficiency in most of the situations and, therefore, was considered as the most appropriate method.

Factors such as poor management and improper operation and maintenance, dissatisfaction of farmers, and the deterioration of irrigation networks under governmental management have made it essential to successfully transfer irrigation system's management to farmers. The purpose of this study was to identify the most important factors affecting successful transition to privatization of irrigation networks management from the viewpoint of water users in the Qazvin network. Sample size was determined using Cochran formula and individual farmers were selected using multi-stage sampling method (n=127). A questionnaire was used to collect the data. The validity of the questionnaire was approved by the judgment of a panel of faculty members and experienced experts. In order to measure the reliability of the questionnaire, Cronbach Alpha coefficient was calculated for the main scales of the questionnaire (0.92). The results showed that the most important factors were facility and financial support of government, skill and proficiency level of irrigation network operators, transparency of the goals and the institutional management method, trust in farmers and their involvement in different activities, and development of technology and machinery. By using exploratory factor analysis, factors in the successful transition were summarized in three factors including trusting and financial/technical support of farmers, administrative transparency, and education and dissemination of information.

In order to study the effects of irrigation water salinity on the yield and yield components of three commercial sunflower hybrids, this experiment was carried out in a randomized complete block design and three replications in Rodasht Agricultural Research Station during three years. The main factors of irrigation water quality were at 4 levels i. e. 2, 5, 8, and 11 dS m-1 and the sub main factors were sunflower hybrids Allstar, Haysan 33, and Azargol. Statistical analysis results showed that salinity and high concentration of some minerals, especially sodium ions, in irrigation water affected the diameter, total oil yieldو and water use efficiency was significant at 1% level, while the effects on plant height, stem diameter, seed weight, grain yield, water use, and oil percent was significant at 5% level. Statistical analysis showed that the effects of hybrids on the diameter, oil yield, plant height, stem diameter, weight of 100 seeds, and water use efficiency were significant at the 1% level, and on yield at 5% level. In terms of performance, hybrids Haysan 33, Azargol, and Allstar had, respectively, the highest seed yield, oil yield, and water use efficiency.

Considering the spatial variations of the parameters affecting crop yield and water requirements over a plain, variation in crop water productivity could be expected. Besides, combination of crop growth simulation model and geographic information system could be used as an appropriate tool to predict crop water productivity over the various parts of a plain. The aim of the current study was to examine the impacts of deficit irrigation on water use efficiency in Mahidasht, as one of the productive plains in Kermanshah province. For this purpose, a field study was designed and implemented to calibrate crop parameters of WOFOST crop growth simulation model. The calibrated WOFOST model was used in CGMS to simulate crop growth over the plain. In CGMS, crop growth simulation model of WOFOST will be applied simultaneously in various homogeneous units. Study area was divided into a number of homogeneous units in terms of biophysical properties (soil and weather). Potential yield and water requirement of barley was estimated in the homogenous units using CGMS based on daily weather data (1992 - 2008) of the meteorological stations within the region or in the adjacent regions. Then, the system was modified and implemented for various deficit irrigation scenarios (20%, 40%, and 60 percent deficit irrigation) for all years and homogeneous units. Crop yield, percent of yield reduction, and water productivity of deficit irrigation scenarios were compared to potential situation i.e. full irrigation. Results indicated that crop water productivity increased with decrease in the amount of irrigation. The highest mean water use efficiency was determined for the scenario of 40% deficit irrigation in the range of 1.37–5.50 kg/m3 (irrigation efficiency of 100%). The mean of water use efficiency for scenarios of full irrigation, 20% and 60% deficit irrigation was determined in the range of 1.08–2.14, 1.34–2.60, and 0.71-3.23 kg/m3, respectively. In addition, the results indicated significant variations in yield and water use efficiency in the various parts of the plain.

Forecasting and monitoring droughts are important elements of optimum water resources management specifically in the metropolitan areas. Also, drought forecasting plays an important role in the planning and management of natural and water resources. Precipitation is the most important parameter used for defining drought, and its lack or deficit implies the threshold of drought. Therefore, in this study, SARIMA model was used to forecast precipitation. Also, SPI index was used to forecast droughts. In this research, considering 35 years (1977 to 2012) of precipitation data from meteorological stations of Kaboodarahang, Hamedan Airport, Nozhgeh, and Bahar, were used for drought forecast in Hamadan province. Based on criteria of AIC and SBC, for stations of Kaboodarahang, Airport, Nozheh, and Bahar the best models were SARIMA(0,0,1)(0,1,1), SARIMA(0,0,1)(0,1,1), SARIMA(0,0,1)(0,1,1) and SARIMA(0,1,1)(1,0,0). Values of R2 and MSE between between stations data and calculated data in stations of Airport, Bahar, Kaboodarahang and Nozheh were 0.92 and 358, 0.94 and 762, 0.97 and 487, 0.88 and 391, respectively. Based on SPI index, the results indicated weak droughts in the four stations for 2012 to 2017.

Drought, among the natural calamities, has the first rank in the view of severity, duration, and damage. To estimate the drought, it is necessary to use dynamic models in which the dominant processes on drought phenomenon are considered. Artificial neural networks models are dynamic models which are able to determine the relation of the inputs and outputs of a physical system joining together through nods. This research was performed to predict drought phenomenon in Mashhad synoptic station using perceptron and gradient descent with momentum training algorithm and gradient descent. The model input variables for SPI index consist of precipitation, climate large-scale index of SOI and NAO during 1951- 2007, and network output is SPI index in time delays; and input variables for PDSI index include precipitation, SOI, NAO and temperature during 1951- 2007, and the network output is PDSA index in different time delays. For modeling the SPI index, 57-year rainfall data of Mashhad synoptic station was used, of which 46 years were used for the network training and the rest (11 years) for the network testing. To model PDSI, 52-years statistical data was utilized; 33years for the network training and 9 years for validation and the rest 10 years for the network testing, by using Nero Solutions5 software. Also, for investigating the relation of ENSO with the precipitation of Mashhad synoptic station, regression method was used. Results showed that the southern fluctuations have small effect on this station precipitation and the northern atlas fluctuations have no effect on them. Occurrence of strong ENSO phenomenon in the world has affected the precipitations of Mashhad synoptic station, and the year after that, la Nina caused drought and low rainfall in this station. Occurrence of ENSO warm phase leads to increase in winter rainfall and lower rainfall in other seasons. Because of wide range of rainfall changes in time spans of 1, 2, and 3 months, the accuracy of predicted results by these time series is very low and by increasing of index time scale, the range of precipitation changes decreases while the results accuracy increases. The models of perceptron and feed forward operate well in predicting drought. Operation criteria R2= 0.78 for predicting 18-month SPI, and R2= 0.76 for predicting PSDI reflect this fact.

Water user's participation in agricultural water projects is necessary for proper operation and maintenance of irrigation and drainage systems and it is one of the most important issues in development of growing communities. In Alborz Integrated Land and Water Management Project (AILWMP), due to the strategic policies and the support of the World Bank, a key goal of the project is the formation of Water Users’ Associations (WUAs). The sample population of this study was 103 board members of 19 WUAs within the AILWMP area in Mazandaran province. Field data collection instrument was a questionnaire which was validated using Cronbach– alpha, calculated at 0.73. To design the questionnaire, the Delphi method was used and, to evaluate the effective components, ten categories were determined and weighted. The first priority was sustainability, which was the main goal of the organization based on the project document. Necessity of organizing the WUA as well as education and information dissemination indexes were the second priority. Task definition and satisfaction indexes were considered as the third priority. To ensure the accuracy of answers, the questionnaire used active researchers approach. The research results showed that, up to this stage, WUA's progress have been fairly successful. The effective indexes of WUAs’ success were identified as information and training, the need to create association, roles definition, and sustainability, with respective weights of 0.326, 0.292, 0.266, and 0.239. Therefore, these components must be implemented carefully in future projects to achieve successful WUAs.

In rural areas, where water tends to be traded less and is mostly used as an essential farm input, water users’ association (WUA) can be an alternative for water resource management. The aim of this study was to compare characteristics of farmers who accept or refuse WUA. Statistical population included all farmers of Feyzabad Dam network (192 farmers) and 120 farmers were selected through stratified random sampling. This study was conducted in 2011. Data was collected using a questionnaire. Face validity of the questionnaire was obtained through a panel of experts and reliability was obtained through pilot testing. The Cronbach's alpha ranged from 0.73 to 0.93. Discriminant analysis test was used to compare farmers. Results revealed that farmers accepting WUA in compare with those who refused it had more positive attitude towards water users associations, more information about associations, less history of dispute over water, more trust, consistency and social participation, and were less satisfied with Exploitation Company of the network.